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Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate various embodiments of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner. DETAILED DESCRIPTION Applicant of the present application owns the following U.S. Patent Applications that were filed on Mar. 24, 2021 and which are each herein incorporated by reference in their respective entireties: U.S. patent application Ser. No. 17/211,145, entitled METHOD OF USING A POWERED STAPLING DEVICE, now U.S. Patent Application Publication No. 2022/0304679; U.S. patent application Ser. No. 17/211,161, entitled SURGICAL STAPLING ASSEMBLY COMPRISING NONPLANAR STAPLES AND PLANAR STAPLES, now U.S. Patent Application Publication No. 2022/0304684; U.S. patent application Ser. No. 17/211,168, entitled SURGICAL STAPLE CARTRIDGE COMPRISING LONGITUDINAL SUPPORT BEAM, now U.S. Patent Application Publication No. 2022/0304685; U.S. patent application Ser. No. 17/211,172, entitled ROTARY-DRIVEN SURGICAL STAPLING ASSEMBLY COMPRISING ECCENTRICALLY DRIVEN FIRING MEMBER, now U.S. Patent Application Publication No. 2022/0304686; U.S. patent application Ser. No. 17/211,175, entitled ROTARY-DRIVEN SURGICAL STAPLING ASSEMBLY COMPRISING A FLOATABLE COMPONENT, now U.S. Patent Application Publication No. 2022/0304687; U.S. patent application Ser. No. 17/211,182, entitled DRIVERS FOR FASTENER CARTRIDGE ASSEMBLIES HAVING ROTARY DRIVE SCREWS, now U.S. Patent Application Publication No. 2022/0304680; U.S. patent application Ser. No. 17/211,189, entitled MATING FEATURES BETWEEN DRIVERS AND UNDERSIDE OF A CARTRIDGE DECK, now U.S. Patent Application Publication No. 2022/0304681; U.S. patent application Ser. No. 17/211,192 entitled LEVERAGING SURFACES FOR CARTRIDGE INSTALLATION, now U.S. Patent Application Publication No. 2022/0304690; U.S. patent application Ser. No. 17,211,197, entitled FASTENER CARTRIDGE WITH NON-REPEATING FASTENER ROWS, now U.S. Patent Application Publication No. 2022/0304682; U.S. patent application Ser. No. 17/211,207, entitled FIRING MEMBERS HAVING FLEXIBLE PORTIONS FOR ADAPTING TO A LOAD DURING A SURGICAL FIRING STROKE, now U.S. Patent Application Publication No. 2022/0304688; U.S. patent application Ser. No. 17/211,222, entitled MULTI-AXIS PIVOT JOINTS FOR SURGICAL INSTRUMENTS AND METHODS OF MANUFACTURING SAME, now U.S. Patent Application Publication No. 2022/0304714; U.S. patent application Ser. No. 17/211,230, entitled JOINT ARRANGEMENTS FOR MULTI-PLANAR ALIGNMENT AND SUPPORT OF OPERATIONAL DRIVE SHAFTS IN ARTICULATABLE SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2022/0304715; and U.S. patent application Ser. No. 17/211,242, entitled SURGICAL INSTRUMENT ARTICULATION JOINT ARRANGEMENTS COMPRISING MULTIPLE MOVING LINKAGE FEATURES, now U.S. Patent Application Publication No. 2022/0304683. Applicant of the present application owns the following U.S. Patent Applications and U.S. Patents that were filed on Dec. 19, 2017 and which are each herein incorporated by reference in their respective entireties: U.S. Pat. No. 10,835,330, entitled METHOD FOR DETERMINING THE POSITION OF A ROTATABLE JAW OF A SURGICAL INSTRUMENT ATTACHMENT ASSEMBLY; U.S. Pat. No. 10,716,565, entitled SURGICAL INSTRUMENTS WITH DUAL ARTICULATION DRIVES; U.S. patent application Ser. No. 15/847,325, entitled SURGICAL TOOLS CONFIGURED FOR INTERCHANGEABLE USE WITH DIFFERENT CONTROLLER INTERFACES, now U.S. Patent Application Publication No. 2019/0183491; U.S. Pat. No. 10,729,509 entitled SURGICAL INSTRUMENT COMPRISING CLOSURE AND FIRING LOCKING MECHANISM; U.S. patent application Ser. No. 15/847,315, entitled ROBOTIC ATTACHMENT COMPRISING EXTERIOR DRIVE ACTUATOR, now U.S. Patent Application Publication No. 2019/0183594; and U.S. Design Pat. No. D910,847, entitled SURGICAL INSTRUMENT ASSEMBLY. Applicant of the present application owns the following U.S. Patent Applications and U.S. Patents that were filed on Jun. 28, 2017 and which are each herein incorporated by reference in their respective entireties: U.S. patent application Ser. No. 15/635,693, entitled SURGICAL INSTRUMENT COMPRISING AN OFFSET ARTICULATION JOINT, now U.S. Patent Application Publication No. 2019/0000466; U.S. patent application Ser. No. 15/635,729, entitled SURGICAL INSTRUMENT COMPRISING AN ARTICULATION SYSTEM RATIO, now U.S. Patent Application Publication No. 2019/0000467; U.S. patent application Ser. No. 15/635,785, entitled SURGICAL INSTRUMENT COMPRISING AN ARTICULATION SYSTEM RATIO, now U.S. Patent Application Publication No. 2019/0000469; U.S. patent application Ser. No. 15/635,808, entitled SURGICAL INSTRUMENT COMPRISING FIRING MEMBER SUPPORTS, now U.S. Patent Application Publication No. 2019/0000471; U.S. patent application Ser. No. 15/635,837, entitled SURGICAL INSTRUMENT COMPRISING AN ARTICULATION SYSTEM LOCKABLE TO A FRAME, now U.S. Patent Application Publication No. 2019/0000472; U.S. Pat. No. 10,779,824, entitled SURGICAL INSTRUMENT COMPRISING AN ARTICULATION SYSTEM LOCKABLE BY A CLOSURE SYSTEM; U.S. patent application Ser. No. 15/636,029, entitled SURGICAL INSTRUMENT COMPRISING A SHAFT INCLUDING A HOUSING ARRANGEMENT, now U.S. Patent Application Publication No. 2019/0000477; U.S. patent application Ser. No. 15/635,958, entitled SURGICAL INSTRUMENT COMPRISING SELECTIVELY ACTUATABLE ROTATABLE COUPLERS, now U.S. Patent Application Publication No. 2019/0000474; U.S. patent application Ser. No. 15/635,981, entitled SURGICAL STAPLING INSTRUMENTS COMPRISING SHORTENED STAPLE CARTRIDGE NOSES, now U.S. Patent Application Publication No. 2019/0000475; U.S. patent application Ser. No. 15/636,009, entitled SURGICAL INSTRUMENT COMPRISING A SHAFT INCLUDING A CLOSURE TUBE PROFILE, now U.S. Patent Application Publication No. 2019/0000476; U.S. Pat. No. 10,765,427, entitled METHOD FOR ARTICULATING A SURGICAL INSTRUMENT; U.S. patent application Ser. No. 15/635,530, entitled SURGICAL INSTRUMENTS WITH ARTICULATABLE END EFFECTOR WITH AXIALLY SHORTENED ARTICULATION JOINT CONFIGURATIONS, now U.S. Patent Application Publication No. 2019/0000457; U.S. Pat. No. 10,588,633, entitled SURGICAL INSTRUMENTS WITH OPEN AND CLOSABLE JAWS AND AXIALLY MOVABLE FIRING MEMBER THAT IS INITIALLY PARKED IN CLOSE PROXIMITY TO THE JAWS PRIOR TO FIRING; U.S. patent application Ser. No. 15/635,559, entitled SURGICAL INSTRUMENTS WITH JAWS CONSTRAINED TO PIVOT ABOUT AN AXIS UPON CONTACT WITH A CLOSURE MEMBER THAT IS PARKED IN CLOSE PROXIMITY TO THE PIVOT AXIS, now U.S. Patent Application Publication No. 2019/0000459; U.S. Pat. No. 10,786,253, entitled SURGICAL END EFFECTORS WITH IMPROVED JAW APERTURE ARRANGEMENTS; U.S. patent application Ser. No. 15/635,594, entitled SURGICAL CUTTING AND FASTENING DEVICES WITH PIVOTABLE ANVIL WITH A TISSUE LOCATING ARRANGEMENT IN CLOSE PROXIMITY TO AN ANVIL PIVOT AXIS, now U.S. Patent Application Publication No. 2019/0000461; U.S. patent application Ser. No. 15/635,612, entitled JAW RETAINER ARRANGEMENT FOR RETAINING A PIVOTABLE SURGICAL INSTRUMENT JAW IN PIVOTABLE RETAINING ENGAGEMENT WITH A SECOND SURGICAL INSTRUMENT JAW, now U.S. Patent Application Publication No. 2019/0000462; U.S. Pat. No. 10,758,232, entitled SURGICAL INSTRUMENT WITH POSITIVE JAW OPENING FEATURES; U.S. Pat. No. 10,639,037, entitled SURGICAL INSTRUMENT WITH AXIALLY MOVABLE CLOSURE MEMBER; U.S. Pat. No. 10,695,057, entitled SURGICAL INSTRUMENT LOCKOUT ARRANGEMENT; U.S. Design Pat. No. D851,762, entitled ANVIL; U.S. Design Pat. No. D854,151, entitled SURGICAL INSTRUMENT SHAFT; and U.S. Design Pat. No. D869,655, entitled SURGICAL FASTENER CARTRIDGE. Applicant of the present application owns the following U.S. Patent Applications and U.S. Patents that were filed on Jun. 27, 2017 and which are each herein incorporated by reference in their respective entireties: U.S. patent application Ser. No. 15/634,024, entitled SURGICAL ANVIL MANUFACTURING METHODS, now U.S. Patent Application Publication No. 2018/0368839; U.S. Pat. No. 10,772,629, entitled SURGICAL ANVIL ARRANGEMENTS; U.S. patent application Ser. No. 15/634,046, entitled SURGICAL ANVIL ARRANGEMENTS, now U.S. Patent Application Publication No. 2018/0368841; U.S. Pat. No. 10,856,869, entitled SURGICAL ANVIL ARRANGEMENTS; U.S. patent application Ser. No. 15/634,068, entitled SURGICAL FIRING MEMBER ARRANGEMENTS, now U.S. Patent Application Publication No. 2018/0368843; U.S. patent application Ser. No. 15/634,076, entitled STAPLE FORMING POCKET ARRANGEMENTS, now U.S. Patent Application Publication No. 2018/0368844; U.S. patent application Ser. No. 15/634,090, entitled STAPLE FORMING POCKET ARRANGEMENTS, now U.S. Patent Application Publication No. 2018/0368845; U.S. patent application Ser. No. 15/634,099, entitled SURGICAL END EFFECTORS AND ANVILS, now U.S. Patent Application Publication No. 2018/0368846; and U.S. Pat. No. 10,631,859, entitled ARTICULATION SYSTEMS FOR SURGICAL INSTRUMENTS. Applicant of the present application owns the following U.S. Patent Applications that were filed on Jun. 2, 2020 and which are each herein incorporated by reference in their respective entireties: U.S. Design patent application Ser. No. 29/736,648, entitled STAPLE CARTRIDGE; U.S. Design patent application Ser. No. 29/736,649, entitled STAPLE CARTRIDGE; U.S. Design patent application Ser. No. 29/736,651, entitled STAPLE CARTRIDGE; U.S. Design patent application Ser. No. 29/736,652, entitled STAPLE CARTRIDGE; U.S. Design patent application Ser. No. 29/736,653, entitled STAPLE CARTRIDGE; U.S. Design patent application Ser. No. 29/736,654, entitled STAPLE CARTRIDGE; and U.S. Design patent application Ser. No. 29/736,655, entitled STAPLE CARTRIDGE. Applicant of the present application owns the following U.S. Design Patent Applications and U.S. Patents that were filed on Nov. 14, 2016, and which are each herein incorporated by reference in their respective entireties: U.S. patent application Ser. No. 15/350,621, now U.S. Patent Application Publication No. 2018/0132849, entitled STAPLE FORMING POCKET CONFIGURATIONS FOR CIRCULAR STAPLER ANVIL; U.S. patent application Ser. No. 15/350,624, now U.S. Patent Application Publication No. 2018/0132854, entitled CIRCULAR SURGICAL STAPLER WITH ANGULARLY ASYMMETRIC DECK FEATURES; U.S. Design Pat. No. D833,608, titled STAPLING HEAD FEATURE FOR SURGICAL STAPLER; and U.S. Design Pat. No. D830,550, titled SURGICAL STAPLER. Numerous specific details are set forth to provide a thorough understanding of the overall structure, function, manufacture, and use of the embodiments as described in the specification and illustrated in the accompanying drawings. Well-known operations, components, and elements have not been described in detail so as not to obscure the embodiments described in the specification. The reader will understand that the embodiments described and illustrated herein are non-limiting examples, and thus it can be appreciated that the specific structural and functional details disclosed herein may be representative and illustrative. Variations and changes thereto may be made without departing from the scope of the claims. The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a surgical system, device, or apparatus that “comprises,” “has,” “includes” or “contains” one or more elements possesses those one or more elements, but is not limited to possessing only those one or more elements. Likewise, an element of a system, device, or apparatus that “comprises,” “has,” “includes” or “contains” one or more features possesses those one or more features, but is not limited to possessing only those one or more features. The terms “proximal” and “distal” are used herein with reference to a clinician manipulating the handle portion of the surgical device. The term “proximal” refers to the portion closest to the clinician and the term “distal” refers to the portion located away from the clinician. It will be further appreciated that, for convenience and clarity, spatial terms such as “vertical”, “horizontal”, “up”, and “down” may be used herein with respect to the drawings. However, surgical device are used in many orientations and positions, and these terms are not intended to be limiting and/or absolute. In the following description, terms such as “first,” “second,” “top,” “bottom,” “up,” “down,” and the like are words of convenience and are not to be construed as limiting terms. References to items in the singular should be understood to include items in the plural, and vice versa, unless explicitly stated otherwise or clear from the text. Grammatical conjunctions are intended to express any and all disjunctive and conjunctive combinations of conjoined clauses, sentences, words, and the like, unless otherwise stated or clear from the context. Thus, the term “or” should generally be understood to mean “and/or”, etc. Recitation of ranges of values herein are not intended to be limiting, referring instead individually to any and all values falling within the range, unless otherwise indicated herein, and each separate value within such a range is incorporated into the disclosure as if it were individually recited herein. The words “about,” “approximately” or the like, when accompanying a numerical value, are to be construed as indicating a deviation as would be appreciated by one of ordinary skill in the art to operate satisfactorily for an intended purpose. Similarly, words of approximation such as “approximately” or “substantially” when used in reference to physical characteristics, should be construed to contemplate a range of deviations that would be appreciated by one of ordinary skill in the art to operate satisfactorily for a corresponding use, function, purpose or the like. The use of any and all examples, or exemplary language (“e.g.,” “such as,” or the like) provided herein, is intended merely to better illuminate the embodiments and does not pose a limitation on the scope of the embodiments. No language in the specification should be construed as indicating any unclaimed element as essential to the practice of the embodiments. Various exemplary devices and methods are provided for performing laparoscopic and minimally invasive surgical procedures. However, the reader will readily appreciate that the various methods and devices disclosed herein can be used in numerous surgical procedures and applications including, for example, in connection with open surgical procedures. As the present Detailed Description proceeds, the reader will further appreciate that the various surgical devices disclosed herein can be inserted into a body in any way, such as through a natural orifice, through an incision or puncture hole formed in tissue, etc. The working portions or end effector portions of the surgical devices can be inserted directly into a patient's body or can be inserted through an access device that has a working channel through which the end effector and elongate shaft of a surgical device can be advanced. A surgical stapling system can comprise a shaft and an end effector extending from the shaft. The end effector comprises a first jaw and a second jaw. The first jaw comprises a staple cartridge. The staple cartridge is insertable into and removable from the first jaw; however, other embodiments are envisioned in which a staple cartridge is not removable from, or at least readily replaceable from, the first jaw. The second jaw comprises an anvil configured to deform staples ejected from the staple cartridge. The second jaw is pivotable relative to the first jaw about a closure axis; however, other embodiments are envisioned in which the first jaw is pivotable relative to the second jaw. The surgical stapling system further comprises an articulation joint configured to permit the end effector to be rotated, or articulated, relative to the shaft. The end effector is rotatable about an articulation axis extending through the articulation joint. Other embodiments are envisioned which do not include an articulation joint. The staple cartridge comprises a cartridge body. The cartridge body includes a proximal end, a distal end, and a deck extending between the proximal end and the distal end. In use, the staple cartridge is positioned on a first side of the tissue to be stapled and the anvil is positioned on a second side of the tissue to be stapled. The anvil is moved toward the staple cartridge to compress and clamp the tissue against the deck. Thereafter, staples removably stored in the cartridge body can be deployed into the tissue. The cartridge body includes staple cavities defined therein wherein staples are removably stored in the staple cavities. The staple cavities are arranged in six longitudinal rows. Three rows of staple cavities are positioned on a first side of a longitudinal slot and three rows of staple cavities are positioned on a second side of the longitudinal slot. Other arrangements of staple cavities and staples are contemplated. The staples are supported by staple drivers in the cartridge body. The drivers are movable between a first, or unfired, position and a second, or fired, position to eject the staples from the staple cavities. The drivers are retained in the cartridge body by a retainer which extends around the bottom of the cartridge body and includes resilient members configured to grip the cartridge body and hold the retainer to the cartridge body. The drivers are movable between their unfired positions and their fired positions by a sled. The sled is movable between a proximal position adjacent a proximal end of the cartridge body and a distal position adjacent a distal end of the cartridge body. The sled comprises a plurality of ramped surfaces configured to slide under the drivers and lift the drivers, and the staples supported thereon, toward the anvil. Further to the above, the sled is moved distally by a firing member. The firing member is configured to contact the sled and push the sled toward the distal end. The longitudinal slot defined in the cartridge body is configured to receive the firing member. The anvil also includes a slot configured to receive the firing member. The firing member further comprises a first cam which engages the first jaw and a second cam which engages the second jaw. As the firing member is advanced distally, the first cam and the second cam can control the distance, or tissue gap, between the deck of the staple cartridge and the anvil. The firing member also comprises a knife configured to incise the tissue captured intermediate the staple cartridge and the anvil. It is desirable for the knife to be positioned at least partially proximal to the ramped surfaces such that the staples are ejected into the tissue ahead of the knife transecting the tissue. FIGS.1-8depict a surgical stapling instrument10configured to clamp, staple, and cut tissue of a patient. The surgical stapling instrument10comprises a handle20, a shaft assembly100attached to the handle20, and an end effector200. To cut and staple tissue of a patient, the end effector200comprises a cartridge jaw201and an anvil jaw203. The anvil jaw203is pivotable relative to the cartridge jaw203to clamp tissue between the anvil jaw203and the cartridge jaw203. Once tissue is clamped between the jaws201,203, the surgical stapling instrument10may be actuated to advance a firing member through the jaws201,203to staple and cut tissue with the end effector200as discussed in greater detail below. Discussed in greater detail below, the end effector200is articulatable by way of an articulation region110of the shaft assembly100. Such articulation provides a user of the surgical stapling instrument10with the ability to position and/or maneuver the end effector200near the target tissue more accurately. The handle20comprises a housing21configured to house various mechanical and electrical components and a handle portion22extending from the housing21. The handle portion22is configured to fit in the palm of a user and/or be gripped and/or held by a user using the surgical stapling instrument10. The handle20further comprises various actuators and/or triggers configured to be actuated by a user to operate one or more functions of the surgical stapling instrument10. The handle20comprises a closure trigger24, a firing trigger25, and at least one articulation actuator26. When actuated by a user, the closure trigger24is configured to clamp tissue with the end effector200by moving the anvil jaw203toward the cartridge jaw201. When actuated by a user, the firing trigger25is configured to cut and staple tissue with the end effector200by advancing a firing member to eject staples and cut tissue with a knife. When actuated by a user, the articulation actuator26is configured to articulate the end effector200relative to the shaft assembly100by way of the articulation region110. The triggers and actuators of the surgical stapling instrument10can either trigger one or more motors within the handle20to actuate various function of the surgical stapling instrument10and/or manually drive various drive shafts and components to actuate various function of the surgical stapling instrument10. The handle20further comprises a nozzle assembly30configured to support the shaft assembly100therein. The nozzle assembly30comprises an actuation wheel31configured to be rotated by a user to rotate the shaft assembly100and end effector200about a longitudinal axis LA relative to the handle20. Such a mechanism permits the user of the surgical stapling instrument10to rotate only the shaft assembly100and/or end effector200without having to rotate the entire handle20. The handle20further comprises a battery23configured to provide power to various electronic components, sensors, and/or motors of the surgical stapling instrument10. Embodiments are envisioned where the surgical stapling instrument10is directly connected to a power source. Embodiments are also envisioned where the surgical stapling instrument10is entirely manual or, non-powered, for example. Embodiments are further envisioned where articulation of the end effector, clamping and unclamping of the jaws, firing of the end effector staple and cut tissue, and shaft and/or end effector rotation are all powered systems. In at least one instance, the shaft assembly100and the end effector200may be modular and removable from the handle20. In at least one instance, the end effector200may be modular in that the end effector200can be removed from the shaft assembly100and replaced with a different end effector. In at least one instance, the shaft assembly100and/or the end effector200is employable in a surgical robotic environment. Such an embodiment would provide powered inputs from a surgical robotic interface to actuate each function of the end effector200. Examples of such surgical robots and surgical tools are further described in U.S. Patent Application Publication No. 2020/0138534, titled ROBOTIC SURGICAL SYSTEM, which published on May 7, 2020, which is incorporated by reference herein in its entirety. In at least one instance, the shaft assembly100and the end effector200are configured to be used with a surgical robot. In such an instance, the shaft assembly100and the end effector200are configured to be coupled to a surgical robot comprising a plurality of output drives. The plurality of output drives of the surgical robot are configured to mate with the drive systems of the shaft assembly100and end effector200. In such an instance, the surgical robot can actuate the various different functions of the end effector200such as, for example, articulating the end effector about multiple different articulation joints, rotating the shaft assembly100and/or end effector200about its longitudinal axis, clamping the end effector200to clamp tissue between the jaws of the end effector200, and/or firing the end effector200to cut and/or staple tissue. The shaft assembly100is configured to house various drive system components and/or electronic components of the surgical stapling instrument10so that the end effector200and shaft assembly100may be inserted through a trocar for laparoscopic surgery. The various drive system components are configured to be actuated by the various triggers and actuators of the handle20. Such components can include drive shafts for articulation, drive shafts for clamping and unclamping the end effector200, and/or drive shafts for firing the end effector200. Such drive shafts may be rotated by a drive system in the handle20or a surgical robotic interface in the instance where the shaft assembly100is connected to the same. In various aspects, a stapling end effector can include two independently rotatable drive members—one for grasping tissue and one for firing staples, for example. The stapling end effector can further include an articulation joint, and the rotary motions can be transmitted through the articulation joint. In various aspects, the stapling end effector can include one or more 3D printed assemblies, which can be incorporated into an articulation, grasping, or firing systems. Such drive shafts may be actuated by a drive system in the handle20or a surgical robotic interface in the instance where the shaft assembly100is connected to the same. Such drive shafts may comprise linear actuation, rotary actuation, or a combination thereof. A combination of rotary actuation and linear actuation may employ a series of rack gears and/or drive screws, for example. In at least one instance, the shaft assembly100is also configured to house electrical leads for various sensors and/or motors, for example, positioned within the shaft assembly100and/or end effector200, for example. The shaft assembly100comprises an outer shaft101extending from the nozzle assembly30to the articulation region110comprising dual articulation joints, discussed in greater detail below. The articulation region110allows the end effector200to be articulated relative to the outer shaft101in two distinct planes about two separate axes AA1, AA2. Referring now primarily toFIG.4, articulation of the end effector200will now be described. The articulation region110comprises two distinct articulation joints and two articulation actuators150,160. This allows the end effector200to be articulated in two different planes about two different axes AA1, AA2independently of each other. The articulation region110comprises a proximal joint shaft component120, an intermediate joint shaft component130, and a distal joint shaft component140. The proximal joint shaft component120is attached to a distal end of the shaft assembly100, the intermediate joint shaft component130is pivotally connected to the proximal joint shaft component120and the distal joint shaft component140, and the distal joint shaft component140is fixedly attached to the end effector200by way of a retention ring146. Discussed in greater detail below, this arrangement provides articulation of the end effector200relative to the shaft assembly100about axis AA1and axis AA2independently of each other. The proximal joint shaft component120comprises a proximal annular portion121fixedly fitted within the outer shaft101. The proximal joint shaft component120also includes a hollow passage122to allow various drive system components to pass therethrough, and further includes an articulation tab123comprising a pin hole124configured to receive articulation pin125. The articulation pin125pivotally connects the proximal joint shaft component120to a proximal articulation tab131of the intermediate joint shaft component130. To articulate the end effector200about axis AA1, the articulation actuator150is actuated linearly either in a distal direction or a proximal direction. Such an actuator may comprise a bar or rod made of any suitable material such as metal and/or plastic, for example. The articulation actuator150is pivotally mounted to an articulation crosslink151. The articulation crosslink151is pivotally mounted to the intermediate joint shaft component130off-axis relative to the articulation pin125so that when the articulation actuator150is actuated, a torque is applied to the intermediate joint shaft component130off-axis relative to the articulation pin125by the articulation crosslink151to cause the intermediate joint shaft component130and, thus, the end effector200, to pivot about axis AA1relative to the proximal joint shaft component120. The intermediate joint shaft component130is pivotally connected to the proximal joint shaft component120by way of the articulation pin125which defines axis AA1. Specifically, the intermediate joint shaft component130comprises a proximal articulation tab131that is pivotally connected to the proximal joint shaft component120by way of the articulation pin125. The intermediate joint shaft component130further comprises a hollow passage132configured to allow various drive system components to pass therethrough and a distal articulation tab133. The distal articulation tab133comprises a pin hole134configured to receive another articulation pin136, which defines axis AA2, and a distally-protruding key135. To articulate the end effector200about axis AA2, the articulation cable160is actuated to apply an articulation torque to a proximal tab141of the distal joint shaft component140by way of the key135. The articulation cable160is fixed to the key135such that, as the cable160is rotated, the key135is pivoted relative to the intermediate joint shaft component130. The key135is fitted within a key hole144of the distal joint shaft component140. Notably, the key135is not fixed to the intermediate joint shaft component130and the key135can be rotated relative to the intermediate joint shaft component130. The articulation cable160also contacts the proximal tab141around the pin hole142. This provides an additional torque moment from the articulation cable160to the distal joint shaft component140. The articulation pin136is received within the pin hole142to pivotally couple the intermediate joint shaft component130and the distal joint shaft component140. In at least one instance, the articulation cable160is only able to be pulled in a proximal direction. In such an instance, only one side of the articulation cable160would be pulled proximally to articulate the end effector200in the desired direction. In at least one instance, the articulation cable160is pushed and pulled antagonistically. In other words, the cable160can comprise a rigid construction such that one side of the articulation cable160is pushed distally while the other side of the articulation cable160is pulled proximally. Such an arrangement can allow the articulation forces to be divided between the pushed half of the cable160and the pulled half of the cable160. In at least one instance, the push-pull arrangement allows greater articulation forces to be transmitted to the corresponding articulation joint. Such forces may be necessary in an arrangement with two articulation joints. For example, if the proximal articulation joint is fully articulated, more force may be required of the articulation actuator meant to articulate the distal articulation joint owing to the stretching and/or lengthened distance that the articulation actuator for the distal articulation joint must travel. The distal joint shaft component140further comprises a cutout143to allow various drive components to pass therethrough. The retention ring146secures a channel210of the cartridge jaw201to the distal joint shaft component140thereby fixing the end effector assembly200to a distal end of the articulation region110. As discussed above, the anvil jaw201is movable relative to the cartridge jaw203to clamp and unclamp tissue with the end effector200. Operation of this function of the end effector200will now be described. The cartridge jaw201comprises the channel210and a staple cartridge220configured to be received within a cavity214of the channel210. The channel210further comprises an annular groove211configured to receive the retention ring146and a pair of pivot holes213configured to receive a jaw-coupling pin233. The jaw coupling pin233permits the anvil jaw203to be pivoted relative to the cartridge jaw201. The anvil jaw203comprises an anvil body230and a pair of pivot holes231. The pivot holes231in the proximal portion of the anvil jaw203are configured to receive the jaw-coupling pin233thereby pivotally coupling the anvil jaw203to the cartridge jaw201. To open and close the anvil jaw203relative to the cartridge jaw201, a closure drive250is provided. The closure drive250is actuated by a flexible drive segment175comprised of universally-movable joints arranged or formed end-to-end. In various instances, the flexible drive segment175can includes serial 3D-printed universal joints, which are printed all together as a single continuous system. Discussed in greater detail below, the flexible drive segment175is driven by an input shaft traversing through the shaft assembly100. The flexible drive segment175transmits rotary actuation motions through the dual articulation joints. The closure drive250comprises a closure screw251and a closure wedge255threadably coupled to the closure screw251. The closure wedge255is configured to positively cam the anvil jaw203open and closed. The closure screw251is supported by a first support body258and a second support body259secured within the channel210. To move the anvil jaw203between a clamped position (FIG.8) and an unclamped position (FIG.7), a closure drive shaft is actuated to actuate the flexible drive segment175. The flexible drive segment175is configured to rotate the closure screw251, which displaces the closure wedge255. For example, the closure wedge255is threadably coupled to the closure screw251and rotational travel of the closure wedge255with the staple cartridge220is restrained. The closure screw251drives the closure wedge255proximally or distally depending on which direction the closure screw251is rotated. To clamp the end effector200from an unclamped position (FIG.7), the closure wedge255is moved proximally. As the closure wedge255is moved proximally, a proximal cam surface256of the closure wedge255contacts a corresponding cam surface234defined in a proximal end235of the anvil body230. As the cam surface256contacts the cam surface234, a force is applied to the proximal end235of the anvil body230causing the anvil body230to rotate into the clamped position (FIG.8) about the pin233. To open or unclamp the end effector200from a clamped position (FIG.8), the closure wedge255is moved distally by rotating the closure screw251in a direction opposite to the direction that causes the closure wedge255to move proximally. As the closure wedge255is moved distally, a pair of nubs257extending from a distal end of the closure wedge255contact the cam surface234near a downwardly extending tab237of the anvil body230. As the nubs257contact the cam surface234near the tab237, a force is applied to the anvil body230to rotate the anvil body230into the open position (FIG.7) about the pin233. In at least one instance, the profile of the cam surface234corresponds to the profile of the cam surface256. For example, the cam surface234and the cam surface256may match such that a maximum cam force is applied to the anvil body230to cause the desired rotation of the anvil body230. As can be seen inFIG.8, for example, the cam surface234defined by the proximal end235of the anvil body230comprises a ramped section similar to that of the upper ramped section of the cam surface256. As discussed above, the surgical stapling instrument10may be actuated to advance a firing member through the jaws201,203to staple and cut tissue with the end effector200. The function of deploying staples226from the staple cartridge220and cutting tissue with knife283will now be described. The staple cartridge220comprises a cartridge body221, a plurality of staple drivers225, and a plurality of staples226removably stored within the cartridge body221. The cartridge body221comprises a deck surface222, a plurality of staple cavities223arranged in longitudinal rows defined in the cartridge body221, and a longitudinal slot224bifurcating the cartridge body221. The knife283is configured to be driven through the longitudinal slot224to cut tissue clamped between the anvil body230and the deck surface221. The deck surface221comprises a laterally-contoured tissue-supporting surface. In various aspects, the contour of the deck surface221can form a peak along a central portion of the cartridge body221. Such a peak can overlay a longitudinally-extending firing screw261that extends through the central portion of the cartridge body221, which is further described herein. The increased height along the peak can be associated with a smaller tissue gap along a firing path of the knife283in various instances. In certain aspects of the present disclosure, driver heights, formed staple heights, staple pocket extension heights, and/or staple overdrive distances can also vary laterally along the deck surface221. Laterally-variable staple formation (e.g. a combination of 2D staples and 3D staples) is also contemplated and further described herein. The staple drivers225are configured to be lifted by a sled280as the sled280is pushed distally through the staple cartridge220to eject the staples226supported by the staple drivers225in the staple cavities223. The sled280comprises ramps281to contact the staple drivers225. The sled280also includes the knife283. The sled280is configured to be pushed by a firing member270. To deploy the staples226and cut tissue with the knife283, the end effector200comprises a firing drive260. The firing drive260is actuated by a flexible drive shaft176. Discussed in greater detail below, the flexible drive shaft176is driven by an input shaft traversing through the shaft assembly100. The flexible drive shaft176transmits rotary actuation motions through the dual articulation joints. The firing drive260comprises a firing screw261configured to be rotated by the flexible drive shaft176. The firing screw261comprises journals supported within bearings in the support member259and the channel210. In various instances, the firing screw261can float relative to the channel210, as further described herein. The firing screw261comprises a proximal end262supported within the support member259and the channel210, a distal end263supported within the channel210, and threads265extending along a portion of the length of the firing screw261. The firing member270is threadably coupled to the firing screw261such that as the firing screw261is rotated, the firing member270is advanced distally or retracted proximally along the firing screw261. Specifically, the firing member270comprises a body portion271comprising a hollow passage272defined therein. The firing screw261is configured to be received within the hollow passage272and is configured to be threadably coupled with a threaded component273of the firing member270. Thus, as the firing screw261is rotated, the threaded component273applies a linear force to the body portion271to advance the firing member270distally or retract the firing member270proximally. As the firing member270is advanced distally, the firing member270pushes the sled280. Distal movement of the sled280causes the ejection of the staples223by engaging the plurality of staple drivers225, as further described herein. The driver225is a triple driver, which is configured to simultaneously fire multiple staples223. The driver225can comprise lateral asymmetries, as further described herein, to maximum the width of the sled rails and accommodate the firing screw261down the center of the cartridge220in various instances. At a point during firing of the end effector200, a user may retract the firing member270to allow unclamping of the jaws201,203. In at least one instance, the full retraction of the firing member270is required to open the jaws201,203where upper and lower camming members are provided on the body portion271which can only be disengaged from the jaws201,203once the firing member270is fully retracted. In various instances, the firing member270can be a hybrid construction of plastic and metal portions as further described herein. In various instances, the threaded component273can be a metal component, for example, which is incorporated into the firing member body271with insert molding or over molding. The firing member270can also be referred to an I-beam in certain instances. The firing member270can include a complex 3D-printed geometry comprising a lattice pattern of spaces therein. In various instances, 3D printing can allow the firing member or a portion thereof to act as a spring and allows a portion to more readily flex, which can improve the force distribution and/or tolerances during a firing stroke, for example. FIGS.9-11depict a surgical stapling assembly300comprising a shaft assembly310and the end effector200ofFIGS.1-8attached to the shaft assembly310. The shaft assembly310may be similar in many respects to various other shaft assemblies discussed herein; however, the shaft assembly310comprises a single articulation joint and an articulation bar configured to articulate the end effector200about the single articulation joint. The surgical stapling assembly300is configured to cut and staple tissue. The surgical stapling assembly300may be attached to a surgical instrument handle and/or surgical robotic interface. The surgical instrument handle and/or surgical robotic interface can be configured to actuate various functions of the surgical stapling assembly300. The shaft assembly310comprises an articulation joint320. Discussed in greater detail below, the end effector200is configured to be articulated relative to an outer shaft311of the shaft assembly310about axis AA. The shaft assembly310comprises the outer shaft311, a first shaft joint component330, and a second shaft joint component350pivotally coupled to the first shaft joint component330by way of an articulation pin354. The first shaft joint component330comprises a proximal tube portion331configured to fit within the inner diameter of the outer shaft311. Such a fit may comprise a press fit, for example. However, any suitable attachment means can be used. The first shaft joint component330also includes a distal portion332. The distal portion332comprises an articulation tab333comprising a pin hole334defined therein and a hollow passage335through which various drive components of the surgical stapling assembly300can pass. Such drive components can include articulation actuators, closure actuators, and/or firing actuators for example. The first shaft joint component330is pivotally connected to the second shaft joint component350by way of the articulation pin354. The articulation pin354is also received within a pin hole353of a proximally-extending articulation tab351of the second shaft joint component350. The pin hole353is axially aligned with the pin hole334. The articulation pin354allows the second shaft joint component350to be articulated relative to the first shaft joint component330about the articulation axis AA. The second shaft joint component350further comprises a pin protrusion352extending from the proximal-extending articulation tab351. Discussed in greater detail below, the pin protrusion352is configured to be pivotally coupled to an articulation drive system. The second shaft joint component350further comprises a distal portion355comprising an annular groove356configured to receive a retention ring358. The distal portion355also includes a hollow passage357through which various drive components of the surgical stapling assembly300can pass. The retention ring358is configured to hold the first jaw201to the second shaft joint component350by fitting within the annular groove211of the cartridge channel210and the annular groove356of the second shaft joint component350. To articulate the end effector200about the articulation axis AA, an articulation bar360is provided. The articulation bar360may be actuated by any suitable means such as, for example, by a robotic or motorized input and/or a manual handle trigger. The articulation bar360may be actuated in a proximal direction and a distal direction, for example. Embodiments are envisioned where the articulation system comprises rotary driven actuation in addition to or, in lieu of, linear actuation. The articulation bar360extends through the outer shaft311. The articulation bar360comprises a distal end361pivotally coupled to an articulation link362. The articulation link362is pivotally coupled to the pin protrusion352extending from the proximally-extending articulation tab351off center with respect to the articulation axis AA. Such off-center coupling of the articulation link362allows the articulation bar360to apply a force to the second joint shaft component350to rotate the second shaft joint component350and, thus, the end effector200, relative to the first joint shaft component330. The articulation bar360can be advanced distally to rotate the end effector200in a first direction about the articulation axis AA and retracted proximally to rotate the end effector200in a second direction opposite the first direction about the articulation axis AA. The shaft assembly310further comprises an articulation component support structure340positioned within the articulation joint320. Such a support structure can provide support to various drive components configured to pass through the articulation joint320to the end effector200as the end effector200is articulated. The support structure340may also serve to isolate the drive components from tissue remnants during use. FIGS.12-14depict a surgical stapling assembly400comprising a shaft assembly410and the end effector200ofFIGS.1-8attached to the shaft assembly410. The shaft assembly410may be similar in many respects to various other shaft assemblies discussed herein; however, the shaft assembly410comprises a single articulation joint and an articulation cable configured to articulate the end effector200about the single articulation joint. The surgical stapling assembly400is configured to cut and staple tissue. The surgical stapling assembly400may be attached to a surgical instrument handle and/or surgical robotic interface. The surgical instrument handle and/or surgical robotic interface can be configured to actuate various functions of the surgical stapling assembly400. The shaft assembly410comprises an articulation joint420. Discussed in greater detail below, the end effector200is configured to be articulated relative to an outer shaft411of the shaft assembly310about an axis AA. The shaft assembly410comprises the outer shaft411, a first shaft joint component430, and a second shaft joint component450pivotally coupled to the first shaft joint component430by way of an articulation pin454. The first shaft joint component430comprises a proximal tube portion431configured to fit within the inner diameter of the outer shaft411. Such a fit may comprise a press fit, for example. However, any suitable attachment means can be used. The first shaft joint component430also includes a distal portion432, which comprises an articulation tab433comprising a pin hole434defined therein. The distal portion432further defines a hollow passage435through which various drive components of the surgical stapling assembly400can pass. Such drive components can include articulation actuators, closure actuators, and/or firing actuators, for example. The first shaft joint component430is pivotally connected to the second shaft joint component450by way of the articulation pin454. The articulation pin454is also received within a pin hole453of a proximally-extending articulation tab451of the second shaft joint component450. The articulation pin454allows the second shaft joint component450to be articulated relative to the first shaft joint component430about the articulation axis AA. The second shaft joint component450further comprises a drive ring structure452. The drive ring structure452extends from the proximally-extending articulation tab451and further defines a portion of the pin hole453. Discussed in greater detail below, the drive ring structure452is configured to be engaged by an articulation drive system. The second shaft joint component450further comprises a distal portion455comprising an annular groove456configured to receive a retention ring458. A hollow passage457through the distal portion455is configured to receive various drive components of the surgical stapling assembly400therethrough. The retention ring458is configured to hold the first jaw201to the second shaft joint component450by fitting within the annular groove211of the cartridge channel210and the annular groove456of the second shaft joint component450. To articulate the end effector200about the articulation axis AA, an articulation cable460is provided. The articulation cable460may be actuated by any suitable means such as, for example, by a robotic input and/or a manual trigger on a handle of a handheld surgical instrument. The articulation cable460may comprise an antagonistic actuation profile. In other words, as a first side of the articulation cable460is pulled proximally a second side of the articulation cable460is allowed to advance distally like a pulley system. Similarly, as the second side is pulled proximally, the first side is allowed to advance distally. The articulation cable460extends through the outer shaft411. The articulation cable460is positioned around the drive ring structure452and frictionally retained thereon to permit rotation of the second shaft joint component450as the articulation cable460is actuated. As the articulation cable460is actuated, the articulation cable460is configured to apply a rotational torque to the drive ring structure452of the second joint shaft component450and, thus, the end effector200. Such torque is configured to cause the second joint shaft component450to rotate, or pivot, relative to the first joint shaft component430thereby articulating the end effector200relative to the outer shaft411. A first side of the articulation cable460can pulled to rotate the end effector200in a first direction about the articulation axis AA and a second side of the articulation cable460can be pulled to rotate the end effector200in a second direction opposite the first direction about the articulation axis AA. The shaft assembly410further comprises an articulation component support structure440positioned within the articulation joint420. Such a support structure440can provide support to various drive components configured to pass through the articulation joint420to the end effector200as the end effector200is articulated. The support structure440may also serve to isolate the drive components from tissue remnants during use. The surgical stapling assembly400further comprises a closure drive shaft segment475and a firing drive shaft segment476each configured to transmit rotary motion through the articulation joint420to the end effector200. The drive shaft segments475,476are configured to passively expand and contract longitudinally as the end effector200is articulated. For example, articulation can cause expansion and contraction of the drive shaft segments475,476to account for the respective longitudinal stretching of or contracting of the length of the drive shafts owing to articulation of the end effector200relative to the shaft assembly410. During expansion and contraction of the drive shaft segments475,476, the drive shaft segments475,476maintain rotary driving engagement with corresponding input shafts extending through the outer shaft411and output shafts in the end effector200. In at least one instance, the output shafts comprise the closure screw251, which is configured to effect grasping, closing, or tissue manipulation with the jaws201,203, and the firing screw261, which is configured to effect clamping of the jaws201,203and firing of the firing member270. FIGS.15-17depict a surgical stapling assembly500comprising a shaft assembly510and the end effector200ofFIGS.1-8attached to the shaft assembly510. The shaft assembly510may be similar in many respects to various other shaft assemblies discussed herein; however, the shaft assembly510comprises a single articulation joint and drive shaft segments configured to passively expand and contract. The surgical stapling assembly500is configured to cut and staple tissue. The surgical stapling assembly500may be attached to a surgical instrument handle and/or surgical robotic interface. The surgical instrument handle and/or surgical robotic interface can be configured to actuate various functions of the surgical stapling assembly500. The shaft assembly510comprises an articulation joint520. Discussed in greater detail below, the end effector200is configured to be articulated about an axis AA. The shaft assembly510comprises a first shaft joint component530and a second shaft joint component540pivotally coupled to the first shaft joint component530by way of an articulation pin543. The first shaft joint component530is configured to be attached to a shaft of a surgical instrument assembly and/or a surgical robotic interface. The first shaft joint component530comprises a proximal portion531and an articulation tab533comprising a pin hole534defined therein. In at least one instance, the first shaft joint component530comprises a hollow passage through which various drive components of the surgical stapling assembly400can pass. Such drive components can include articulation actuators, closure actuators, and/or firing actuators for example. The first shaft joint component530is pivotally connected to the second shaft joint component540by way of the articulation pin543. The articulation pin543is also received within a pin hole542of a proximally-extending articulation tab541of the second shaft joint component540. The articulation pin543allows the second shaft joint component540to be articulated relative to the first shaft joint component530about the articulation axis AA. The second shaft joint component540further comprises a distal portion545comprising an annular groove547configured to receive a retention ring548and a hollow passage546through which various drive components of the surgical stapling assembly500can pass. The retention ring548is configured to hold the first jaw201to the second shaft joint component540by fitting within the annular groove211of the cartridge channel210and the annular groove547of the second shaft joint component540. Any suitable articulation drive system can be used to articulate the end effector200about axis AA. In at least one instance, the end effector200is passively articulated. In such an instance, the end effector200may be pressed against tissue, for example, to apply a force to the end effector200and cause the end effector200to articulate about an articulation axis. In at least one instance, the end effector200further comprises a spring configured to apply a neutral biasing force to the second shaft joint segment540, for example, to cause the end effector200to be biased toward an unarticulated configuration. The surgical stapling assembly500further comprises a closure drive shaft segment575and a firing drive shaft segment576each configured to transmit rotary motion through the articulation joint520to the end effector200. The drive shaft segments575,576are configured to passively expand and contract longitudinally as the end effector200is articulated. Articulation causes the drive shaft segments575,576to expand and contract to account for the longitudinal stretching of or contracting of the length of the drive shafts owing to articulation of the end effector200. During expansion and contraction of the drive shaft segments575,576, the drive shaft segments575,576maintain rotary driving engagement with corresponding input shafts and output shafts in the end effector200. In at least one instance, the output shafts comprise the closure screw251and the firing screw261, which are further described herein. FIGS.18-20depict a surgical stapling end effector assembly600comprising a shaft portion610and an end effector600. The end effector assembly600is similar in many respects to various other end effector assemblies disclosed herein; however, the end effector assembly600comprises a multi-component firing member driven by a flexible firing shaft. The end effector assembly600is configured to cut and staple tissue. The end effector assembly600may be attached to a surgical instrument handle and/or surgical robotic interface by way of a proximal tab611of the shaft portion610. The surgical instrument handle and/or surgical robotic interface can be configured to actuate various functions of the end effector assembly600. The end effector assembly600comprises a cartridge channel jaw620and an anvil jaw660pivotally mounted to the cartridge channel jaw620to clamp tissue between the cartridge channel jaw620and the anvil jaw660. The cartridge channel jaw620comprises a channel630comprising a proximal end631, a staple cartridge640configured to store a plurality of staples therein and configured to be received within the channel630, and a support brace650fitted within the staple cartridge640. The staple cartridge640and the support brace650are configured to be assembled together prior to installing the staple cartridge640into the channel630. Discussed in greater detail below, the support brace650is configured to further support a firing member assembly as the firing member assembly is advanced through the end effector assembly600. The anvil jaw660is configured to form staples ejected from the staple cartridge640. The anvil jaw660comprises a proximal end661comprising a pair of pin holes662defined therein configured to receive a coupling pin663. The anvil jaw660is pivotable about the coupling pin663between an unclamped position and a fully clamped position. The coupling pin663is also received within a pair of pin holes633defined in the proximal end631of the channel630. The coupling pin663serves to pivotally mount the anvil jaw660to the channel630. In at least one instance, the channel630is mounted to the shaft portion610by way of a retention ring, or band, that fits around an annular groove632of the channel630and annular groove615of the shaft portion610. The retention ring, or band, is configured to hold the channel630to the shaft portion610. The end effector assembly600comprises a closure drive670configured to grasp tissue between the anvil jaw660and the cartridge channel jaw620by pivoting the anvil jaw660relative to the channel630. The end effector assembly600also includes a firing drive680configured to clamp, staple, and cut tissue by deploying a plurality of staples from the staple cartridge640. The closure drive670comprises a closure screw671positioned within the channel630and a closure wedge675threadably coupled to the closure screw671. As the closure screw671is rotated, the closure wedge675is advanced distally or retracted proximally to open or close the anvil jaw660, respectively. The closure drive670may be actuated by any suitable means. For example, a rotary drive shaft may extend through the shaft portion610from an actuation interface, for example, to rotate the closure screw671. Other examples of suitable rotary drive shafts are further described herein. The firing drive680comprises a flexible drive shaft681that is configured to be moved linearly through the end effector assembly600. The flexible drive shaft681may be actuated by a robotic input and/or a manually-actuated drive shaft of a handle assembly, for example. The flexible drive shaft681is configured to extend through a hollow passage614of a distal end613of the shaft portion610and is flexible so that the end effector assembly600may be articulated relative to a shaft from which the end effector600extends. The flexible drive shaft681extends through a clearance slot676defined in the closure wedge675and is fixedly attached to a lower firing member682. The lower firing member682is configured to be reused with different staple cartridges. The staple cartridge640comprises a disposable upper firing member683configured to hookingly engage or, latch, onto the lower firing member682such that the lower firing member582can push or, drive, the upper firing member683through the staple cartridge640and support brace650. In other words, the firing actuation involves a two-part firing member—a disposable upper firing member683incorporated into the cartridge640and a reusable lower firing member682incorporated into the firing drive680, which can be coupled together when the cartridge640is seated in the elongate channel630. The two-part firing member is further described herein. The upper firing member683comprises an upper flange configured to engage and position the anvil jaw660, a knife edge configured to cut tissue, and a latch portion configured to hookingly engage the lower firing member682. The staple cartridge640further comprises a sled684configured to engage staple drivers positioned within the staple cartridge640to eject staples from the staple cartridge640. Because a knife and cutting edge are incorporated into the disposable upper firing member683of the staple cartridge640, a new and/or fresh cutting edge can be supplied with each staple cartridge loaded into the end effector assembly600. The lower firing member682and the upper firing member683are configured to move through the support brace650such that the vertical loads associated with the firing sequence are configured to be distributed through the support brace650, the staple cartridge640, the channel630, and the anvil jaw660. The support brace650may be comprised of a metal material, for example, to be inserted within the staple cartridge640. The support brace650comprises key rails655configured to fit within corresponding key slots defined in a longitudinal slot of the staple cartridge640. The support brace650further comprises a longitudinal slot653configured to receive the knife of the upper firing member683, a cylindrical passage657configured to receive a portion of the upper firing member683, a portion of the lower firing member682, and the flexible drive shaft681. The support brace650further comprises vertical key extensions656configured to be received within corresponding key holes in the cartridge deck. Such extensions may be visible through the cartridge deck when the support brace650is installed within the staple cartridge640. In at least one instance, the support brace650is configured to be inserted into the staple cartridge640from the bottom of the staple cartridge640facing the channel630. The support brace650further comprises a proximal tab651and a distal tab653, which are both configured to be engaged with the channel630. The tabs651,653are configured to distribute at least some of the forces transmitted through the assembly600by the firing drive680and corresponding components. The distal tab651may serve to block the upper and lower firing members683,682from being pushed through a distal end of the support brace650by sharing and/or redistributing the load applied to the support brace650by the firing drive680with the channel630. When the staple cartridge640is replaced so that the end effector assembly600can be reused, the staple cartridge640is removed from the channel jaw630. Removing the staple cartridge640from the channel jaw630removes the upper firing member683, the sled684, the support brace650, and the staple cartridge640. A fresh knife can be provided with a replacement staple cartridge. Various embodiments disclosed herein may be employed in connection with a robotic system700. An exemplary robotic system is depicted inFIGS.21-23, for example.FIG.21depicts a master controller701that may be used in connection with a surgical robot, such as the robotic arm slave cart800depicted inFIG.22, for example. Master controller701and robotic arm slave cart800, as well as their respective components and control systems are collectively referred to herein as a robotic system700. Examples of such systems and devices are disclosed in U.S. Pat. No. 7,524,320, entitled MECHANICAL ACTUATOR INTERFACE SYSTEM FOR ROBOTIC SURGICAL TOOLS, as well as U.S. Pat. No. 9,072,535, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, which are each hereby incorporated by reference herein in their respective entireties. As is known, the master controller701generally includes controllers (generally represented as703inFIG.21) which are grasped by the surgeon and manipulated in space while the surgeon views the procedure via a stereo display702. The controllers701generally comprise manual input devices which preferably move with multiple degrees of freedom, and which often further have an actuatable handle, trigger, or actuator for actuating tools (for example, for closing grasping jaws, applying an electrical potential to an electrode, or the like). As can be seen inFIG.22, in one form, the robotic arm cart800may be configured to actuate one or more surgical tools, generally designated as900. Various robotic surgery systems and methods employing master controller and robotic arm cart arrangements are disclosed in U.S. Pat. No. 6,132,368, entitled MULTI-COMPONENT TELEPRESENCE SYSTEM AND METHOD, the entire disclosure of which is hereby incorporated by reference herein. In various forms, the robotic arm cart800includes a base702from which, in the illustrated embodiment, surgical tools900may be supported. In various forms, the surgical tool(s)900may be supported by a series of manually articulatable linkages, generally referred to as set-up joints804, and a robotic manipulator806. In various embodiments, the linkage and joint arrangement may facilitate rotation of a surgical tool around a point in space, as more fully described in U.S. Pat. No. 5,817,084, entitled REMOTE CENTER POSITIONING DEVICE WITH FLEXIBLE DRIVE, the entire disclosure of which is hereby incorporated by reference herein. The parallelogram arrangement constrains rotation to pivoting about an axis812a, sometimes called the pitch axis. The links supporting the parallelogram linkage are pivotally mounted to set-up joints804(FIG.22) so that the surgical tool further rotates about an axis812b, sometimes called the yaw axis. The pitch and yaw axes812a,812bintersect at the remote center814, which is aligned along an elongate shaft of the surgical tool900. The surgical tool900may have further degrees of driven freedom as supported by the manipulator806, including sliding motion of the surgical tool900along the longitudinal axis “LT-LT”. As the surgical tool900slides along the tool axis LT-LT relative to manipulator806(arrow812c), the remote center814remains fixed relative to the base816of the manipulator806. Hence, the entire manipulator is generally moved to re-position the remote center814. Linkage808of manipulator806may be driven by a series of motors820. These motors actively move linkage808in response to commands from a processor of a control system. The motors820may also be employed to manipulate the surgical tool900. Alternative joint structures and set up arrangements are also contemplated. Examples of other joint and set up arrangements, for example, are disclosed in U.S. Pat. No. 5,878,193, entitled AUTOMATED ENDOSCOPE SYSTEM FOR OPTIMAL POSITIONING, the entire disclosure of which is hereby incorporated by reference herein. While the data communication between a robotic component and the processor of the robotic surgical system is primarily described herein with reference to communication between the surgical tool and the master controller701, it should be understood that similar communication may take place between circuitry of a manipulator, a set-up joint, an endoscope or other image capture device, or the like, and the processor of the robotic surgical system for component compatibility verification, component-type identification, component calibration (such as off-set or the like) communication, confirmation of coupling of the component to the robotic surgical system, or the like. In accordance with at least one aspect, various surgical instruments disclosed herein may be used in connection with other robotically-controlled or automated surgical systems and are not necessarily limited to use with the specific robotic system components shown inFIGS.21-23and described in the aforementioned references. It is common practice during various laparoscopic surgical procedures to insert a surgical end effector portion of a surgical instrument through a trocar that has been installed in the abdominal wall of a patient to access a surgical site located inside the patient's abdomen. In its simplest form, a trocar is a pen-shaped instrument with a sharp triangular point at one end that is typically used inside a hollow tube, known as a cannula or sleeve, to create an opening into the body through which surgical end effectors may be introduced. Such arrangement forms an access port into the body cavity through which surgical end effectors may be inserted. The inner diameter of the trocar's cannula necessarily limits the size of the end effector and drive-supporting shaft of the surgical instrument that may be inserted through the trocar. Regardless of the specific type of surgical procedure being performed, once the surgical end effector has been inserted into the patient through the trocar cannula, it is often necessary to move the surgical end effector relative to the shaft assembly that is positioned within the trocar cannula in order to properly position the surgical end effector relative to the tissue or organ to be treated. This movement or positioning of the surgical end effector relative to the portion of the shaft that remains within the trocar cannula is often referred to as “articulation” of the surgical end effector. A variety of articulation joints have been developed to attach a surgical end effector to an associated shaft in order to facilitate such articulation of the surgical end effector. As one might expect, in many surgical procedures, it is desirable to employ a surgical end effector that has as large a range of articulation as possible. Due to the size constraints imposed by the size of the trocar cannula, the articulation joint components must be sized so as to be freely insertable through the trocar cannula. These size constraints also limit the size and composition of various drive members and components that operably interface with the motors and/or other control systems that are supported in a housing that may be handheld or comprise a portion of a larger automated system. In many instances, these drive members must operably pass through the articulation joint to be operably coupled to or operably interface with the surgical end effector. For example, one such drive member is commonly employed to apply articulation control motions to the surgical end effector. During use, the articulation drive member may be unactuated to position the surgical end effector in an unarticulated position to facilitate insertion of the surgical end effector through the trocar and then be actuated to articulate the surgical end effector to a desired position once the surgical end effector has entered the patient. Thus, the aforementioned size constraints form many challenges to developing an articulation system that can effectuate a desired range of articulation, yet accommodate a variety of different drive systems that are necessary to operate various features of the surgical end effector. Further, once the surgical end effector has been positioned in a desired articulated position, the articulation system and articulation joint must be able to retain the surgical end effector in that locked position during the actuation of the end effector and completion of the surgical procedure. Such articulation joint arrangements must also be able to withstand external forces that are experienced by the end effector during use. Various surgical instruments employ a variety of different drive shaft arrangements that serve to transmit drive motions from a corresponding source of drive motions that is supported in a handle of the surgical instrument or other portion of an automated or robotically controlled system. These drive shaft arrangements must be able to accommodate significant articulated orientations of the end effector while effectively transmitting such drive motions across the articulation joint of the surgical instrument. In addition, due to the above-mentioned size constraints dictated by the sizes of trocars through which the instrument shafts must be inserted, these drive shaft components must occupy as little space as possible within the shaft. To accommodate such requirements, many drive shaft arrangements comprise several movable elements that are coupled together in series. The small sizes (e.g., 4 mm diameter) and numbers of components lead to difficult and lengthy assembly procedures that add to the cost and complexity of the device. As further described herein, a powered stapling device can include two independently rotatable drive members: a first rotary drive member configured to effect closing of the jaws of the end effector and a second rotary drive member configured to effect firing of a staple cartridge installed in the end effector. The first and second rotary drive members are flexible and configured to extend through at least one articulation joint. In such instances, the first and second rotary drive members can transmit rotary actuation motions through the articulation joint(s) when in a non-flexed configuration and when in a flexed configuration. Exemplary rotary drive members are further described herein. The powered stapling assembly further comprises a first jaw, a second jaw, a closure drive comprising the first rotary drive member extending through the articulation joint, and a firing drive comprising the second rotary drive member extending through the articulation joint. The second rotary drive member can be rotatable independent of the first rotary drive member. The closure drive can be activated by a closure trigger, for example, whereupon an actuation of the closure drive effects a rotation of the first rotary drive member, which transmits a rotary motion through the articulation joint to a closure screw. The closure drive further comprises a closure wedge threadably coupled to the closure screw, wherein the closure wedge is configured to engage the first jaw to move the first jaw from an open position to a closed position upon rotation of the first rotary drive member. The firing drive can be activated by a firing trigger, for example, which is separate from the closure trigger. The rotation of the second rotary drive member is separate from the rotation of the first rotary drive member, and a closure motion is separate and distinct from a firing motion. Activation of the firing drive effects a rotation of the second rotary drive member, which transmits a rotary motion through the articulation joint to a firing screw. The firing drive further comprises a firing member threadably coupled to the firing screw, wherein the firing member is configured to camming engage the first jaw and the second jaw and to move a cutting member and/or a staple-firing sled upon rotation of the second rotary drive member. In various instances, at least one component in the powered stapling device can be a 3D-printed component. 3D-printed components can be incorporated into an articulation system, a closure/grasping system, and/or a firing system, as further described herein. 3D printing technology can be utilized to improve component capabilities in certain instances. For example, 3D printing can allow the printed component to exhibit metamaterial properties, such that the 3D-printed components exhibits greater structural strength and stiffness while allowing precision in the forming of small detailed features and optimizing other properties of the component such as selective flexibility and/or lubrication, for example. Exemplary 3D-printed components for the powered stapling device are further described herein and include the flexible rotatable drive member(s), e.g. serial 3D-printed universal joints, the firing member or I-beam, and/or the staple cartridge and/or sub-components thereof. In one instance, the staple cartridge can be a composite plastic-metal 3D-printed component. 3D printing of various components and considerations therefor are further described herein. A method of stapling with such surgical stapling assemblies is also contemplated. The method can include obtaining the surgical stapling assembly and activating, by the closure trigger, the closure drive, wherein the closure wedge is configured to engage the first jaw to move the first jaw from an open position to a closed position upon a rotation of the first rotary drive member. The method can further includes activating, by the firing trigger, the firing drive, wherein the firing member is configured to camming engage the first jaw and the second jaw and to advance a cutting member and a staple-firing sled during a firing motion upon a rotation of the second rotary drive member. Various applications of 3D-printed components in such assemblies are further described herein. Firing elements and various end effector components are subjected to high loads during the firing stroke. The loads imparted may cause deformation and/or wear of the firing elements and/or end effector components. For example, during a firing stroke, a firing element which cammingly engages an anvil and an elongate channel of an end effector may at least partially ride within an anvil slot in the anvil and along the bottom of the elongate channel. During firing, the anvil is in its closed position, however, as the firing element moves through the end effector, the anvil may attempt to move away from the elongate channel due to the forces associated with firing. For example, the force to form the staples, the force to sever the tissue, and the reactionary forces from the clamped tissue as it is cut and stapled. These forces are imparted onto the firing element during firing and can cause deformation or wear on the firing element and/or other end effector components. In various embodiments, end effector components may be constructed using three dimensional (“3D”) printing to improve component capabilities. In certain instances, 3D printing can allow components to exhibit metamaterial properties to aid in lowering the force to fire. A metamaterial is a synthetic composite material with a structure such that it exhibits properties not usually found in natural materials. 3D printing is one technique used to create a metamaterial to form structures with two or more materials. As such, 3D printing allows for the creation of complex geometries and/or material combinations that may otherwise be too costly and time consuming to manufacture or may even be impossible to manufacture absent 3D printing technology. In various embodiments, a firing element may be 3D printed such that its main body acts as a spring to allow the upper and/or lower cam portions to flex and move to contact the anvil and elongate channel at an angle of reduced resistance. FIGS.24and25depict a firing member41000for use with a surgical instrument, such as the surgical instruments disclosed herein. The firing member41000is deformable from a first or unloaded configuration (FIG.24) in the absence of a firing load to a second or expanded configuration (FIG.25) under a firing load. Additional configurations, such as intermediate configurations between the unloaded configuration and the expanded configuration, for example, are also contemplated in response to different firing loads. The firing member41000comprises a proximal firing bar portion41100and a distal head portion41200extending from the firing bar portion41100. Specifically, the firing bar portion41100includes a distal protrusion41110that extends into a cutout portion41250defined in the proximal end of the distal head portion41200. The distal protrusion41110includes arcuate portions and a blunt distal end for driving engagement with the distal head portion41200. Such an arrangement permits assembly of the firing bar portion41100to the distal head portion41200. The distal head portion41200further includes an upper portion41210and a lower portion41220that are movable relative to one another. The cutout portion41250is defined in both the upper and lower portions41210,41220. As such, the distal end of the firing bar portion41100is in engagement with both the upper portion41210and the lower portion41220of the distal head portion41200. Further, the distal head portion41200includes a protruding nose41230that extends distally. The protruding nose41230is configured to engage and drive a sled of a surgical staple cartridge distally during a firing stroke, for example. The protruding nose41230can be configured to defeat a firing lockout of a surgical instrument, for example. Further, the distal head portion41200includes a knife portion or cutting member for severing the tissue of a patient during a firing stroke of the firing member41000in certain aspects of the present disclosure. Further to the above, the distal head portion41200comprises a flexible portion41240that connects the upper portion41210and the lower portion41220of the distal head portion41200. Specifically, the flexible portion41240comprises a top end41260defined in the upper portion41210, and a bottom end41270defined in the lower portion41220. In at least one embodiment, the flexible portion41240is embedded into the distal head portion41200. However, other attachment arrangements are envisioned for the upper portion41220, the lower portion41220, and the flexible portion41240. For example, the entire distal head portion41200may be 3D printed having different materials for the different portions of the distal head41200. In at least one embodiment, the distal head41200is comprised of a first material and the flexible portion41240is comprised of a second material that is different from the first material. For example, the flexible portion41240may be comprised of aluminum and the remainder of the distal head portion41200may be comprised of stainless steel. However, other embodiments are envisioned with different materials for the distal head portion41200and the flexible portion41240such as plastic, ABS, rubber, and/or various polymers. In the illustrated embodiment, the flexible portion41240is shaped like an “I” having an upright portion and orthogonal flanges at both ends of the upright portion, however other embodiments are envisioned with different cross-sectional shapes for the flexible portion41240. Further to the above, the distal head portion41200comprises an upper cam member defined on the upper portion41210, and a lower cam member defined on the lower portion41220. The upper and lower cam members are configured to cammingly engage a first jaw and a second jaw of an end effector of a surgical instrument to approximate the first jaw and the second jaw relative to one another during a firing stroke. As such, the upper portion41210and the lower portion41220may separate to accommodate a transverse load imparted on the distal head portion41200during the firing stroke. Specifically, as depicted inFIG.25, a gap41280may form between the upper portion41210and the lower portion41220of the distal head41200during the firing stroke. In the illustrated embodiment, the upper portion41210moves away from the lower portion41240, which is stationary. The distal end of the firing bar41100includes an extension41120, which extends beyond the height of the upper portion41210when the distal head portion41200and flexible portion41240are undeformed or non-expanded. Further, the extension41120of the firing bar41100is tall enough to accommodate the expansion of the distal head41200. As such, when the distal head41200is expanded, the extension41120of the firing bar41100can maintain driving contact with the proximal end of the distal head41200. In any event, other embodiments are envisioned where both the upper portion41210and the lower portion41220move during a firing stroke in response to a firing load. Further, other embodiments are envisioned where only the lower portion41220moves during a firing stroke. Further to the above, when the distal head41200extends vertically to an expanded configuration, the flexible portion41240stretches vertically while maintaining the connection between the upper and lower portions41210,41220of the distal head41200. When the flexible portion41240is stretched, an intermediate portion41265of the flexible portion41240may neck down or narrow to accommodate a transverse load as depicted inFIG.25. FIG.26depicts a surgical instrument42000comprising an elongate shaft42100, an end effector42200extending from the elongate shaft42100, and a firing member42300configured to move relative to the elongate shaft42100and the end effector42200to perform a firing stroke. The elongate shaft42100may be a closure tube for opening and closing a pair of jaws42240,42210of the end effector42200, for example. The firing member42300comprises a proximal firing bar portion42310and a distal head portion42320extending therefrom. Specifically, the proximal firing bar portion42310includes a distal protrusion42312that extends into a cutout42336defined in the proximal end of the distal head portion42320. Such an arrangement facilitates the assembly of the proximal firing bar portion42310to the distal head portion42320. Further to the above, the distal head portion42320is a two-part assembly formed from an upper portion42330and a lower portion42340that are movable relative to one another. The upper portion42330comprises a distally-protruding lower foot42334and the lower portion42340comprises a proximally-protruding upper foot42342positioned to interact and selectively interlock with the distally-protruding lower foot42334. An opening42400is defined between the distally-protruding lower foot42334and the proximally-protruding upper foot42342when the upper portion42330and the lower portion42340are in a collapsed configuration, as depicted inFIG.26. The opening42400permits the upper portion42330to move relative to the lower portion42340, to an extent, during a firing stroke of the distal head portion42320, as discussed in greater detail below. Further to the above, the distally-protruding lower foot42334extends into a pocket, or cavity42346, in the lower portion42340. The cavity42346defines a flange42348on the proximal end of the lower portion42340. The flange42348extends toward the upper portion42330and prevents the distally-protruding lower foot42334of the upper portion42330from becoming detached from the lower portion42340. Specifically, the opening42400height is smaller than the height of the flange42348and, thus, the upper portion42330and the lower portion42340are prevented from detaching in the longitudinal direction. Further to the above, the upper portion42330and the lower portion42340of the distal head portion42320can be connected via a flexible attachment member, such as the flexible portion41240ofFIG.24, for example, in certain instances. Further, in at least one aspect, the upper portion42330and the lower portion42340of the distal head portion42320can comprise two completely separate components that are not attached, but are held together due to the internal geometry of the elongate shaft42100and end effector42200. Further to the above, The upper portion42330comprises a first cam member configured to cammingly engage the first jaw42240of the end effector42200during a firing stroke, and the lower portion42340comprises a second cam member configured to cammingly engage the second jaw42210of the end effector42200during the firing stroke. As such, the first cam member and the second cam member are configured to approximate the first jaw42240and the second jaw42210of the end effector42200during the firing stroke. In the illustrated embodiment, the first jaw42240comprises a movable anvil, and the second jaw42210comprises an elongate channel configured to receive a staple cartridge42220. The anvil42240is movable relative to the elongate channel42210between an open position and a closed position. Further, the firing member42300is configured to move a sled42230of the staple cartridge42220through the end effector42200to eject staples from the staple cartridge42220. In use, as the firing member42300distally advances from the unfired position depicted inFIG.26, the distal head portion42320advances beyond the distal end of the elongate shaft42100, which can allow for expansion of the distal head portion42320under certain firing loads. The distal head portion42320advances into the end effector42200such that the upper cam member engages the anvil42240and the lower cam member engages the elongate channel42210. As such, the first cam member on the upper portion42330is in camming engagement with the movable anvil42240during the firing stroke, and the second cam member on the lower portion42340is in camming engagement with the elongate channel42210during the firing stroke. The upper portion42330and the lower portion42340are capable of separating or moving farther apart vertically during the firing stroke. For example, when the anvil42240is in its closed position and the firing stroke has commenced, forces due to staple firing, cutting, and/or patient tissue may deflect or move the anvil42240away from the elongate channel42210. The expansion of the distal head portion42320can accommodate such movement or deflection. In certain instances, the expansion of the firing member42320can accommodate entry of the upper cam member on the upper portion42330into an anvil channel of the anvil42200if the anvil channel is misaligned. Further, the expansion of the distal head portion42320is limited by the distally-protruding lower foot42334and the proximally-protruding upper foot42342, which are drawn closer together to close the space42400therebetween and eventually engage one another to limit the extent of expansion of the distal head portion42320. Further to the above, after the distal head portion42320has been distally advanced and expanded, the distal head portion42320can be retracted back to the home or unfired position illustrated inFIG.26. During retraction, a first cam surface42338on the upper portion42330engages a second cam surface42120on the distal end of the elongate shaft42100. The first and second cam surfaces42338,42120interact to compress the distal head42320into its non-expanded state (FIG.26). Further to the above, the lower portion42340of the distal head portion42320comprises a cutout portion42344defined in the distal end of the lower portion42340. The cutout portion42344is configured to receive a proximal nose portion42232of the sled42230therein. As such, a distal advancement of the distal head portion42320will advance the sled42230through the staple cartridge42220to eject the staples. Further, the distal head portion42320comprises a knife portion42332configured to sever the tissue of a patient during the firing stroke. FIGS.27and28depict a stapling attachment43000for use with a surgical instrument, such as those described herein. The stapling attachment43000comprises an elongate shaft43100attachable to a handle and/or housing, and an end effector43200extending from the elongate shaft43100. The end effector43200comprises a first jaw, or anvil43210, and a second jaw, or elongate channel43220. The anvil43210is movable relative to the elongate channel43220between an open position and a closed position in response to a closure motion from a closure system. The anvil43210comprises landing portions43212on its proximal end. Further, a medium and/or low durometer material43214extends from the landing portion43212. The low durometer material43214can comprise rubber, plastic, a polymer and/or any other suitable material, for example. The material43214has a lower durometer than the landing portion43212. In one aspect, the landing portion43212can be metal, and the material43214can be rubber, for example. Further to the above, the elongate channel43220is configured to receive a staple cartridge43230therein. The staple cartridge43230comprises a proximal cartridge tail43232with substantially flat portions on both sides of a cartridge slot43234. Typically, the cartridge tail43232is configured to interact with the landing portions43212of the anvil43210when the anvil43210is in its closed position. In the illustrated embodiment, the low durometer material43214acts as a semi-compressible material between the landing portions43212of the anvil43210and the cartridge tail43232. As such, the anvil43210is capable of floating relative to the staple cartridge43230in response to the forces exerted by the closure system and/or the firing system. Specifically, due to the compressible nature of the low durometer material43214, the anvil43210can flex and/or deflect relative to the staple cartridge43230more than would be possible without the low durometer material43214present on the landing portions43214. Other embodiments are envisioned where the low durometer material43214is defined as part of the anvil43210and flush with the landing portions43212of the anvil43210. In such an arrangement, the low durometer material43214may allow for over-closing of the anvil43210relative to the staple cartridge43230. Specifically, a firing member engages the anvil slot43216and the elongate channel43220to close the anvil43200relative to the staple cartridge43230during an initial closing operation. During the initial closing operation of the anvil43200, the compressible low durometer material43214flush with the landing portions43212can abut and cause interference with the rigid cartridge tail43232of the staple cartridge43230. Because the low durometer material43214is compressible, the proximal portion of the anvil43200is capable of flexing to overcome the interference between the landing portions43212and the cartridge tail43232. As the firing member advances through the staple cartridge43230, the low durometer material43214may further compress against the rigid cartridge tail43232. The two surfaces43214,43232can move past the point of interference to allow the firing member to complete the firing stroke without binding. Further to the above, the low durometer material43214may be more compressible than the anvil43210and/or the cartridge43230. Further, the low durometer material43214may reduce the forces on a firing member which travels through the anvil43210and the staple cartridge slot43234. Specifically, a firing member with an upper and lower cam member, such as those described herein, can move within the end effector43200. For example, the upper cam of the firing member moves through anvil slot43216. Due to the compressibility of the low durometer material43214, the anvil slot43216can flex relative to the staple cartridge43230. As such, less force will be exerted on the upper cam member of the firing member during closing and/or firing as compared to if the low durometer material43214were not present. Further to the above, embodiments are envisioned which incorporate the low durometer material43214and the expanding firing members41000,42320ofFIGS.24-26into an end effector. The compressibility of the low durometer material43214of an anvil, for example, in combination with the expanding capabilities of the firing members41000or42320, for example, can provide an end effector with greater variability during the firing stroke. Specifically, the low durometer material43214can allow the anvil to float more relative to the cartridge, and the expanding firing members41000,42320can allow for greater leeway in alignment between the firing member flanges and the anvil slot. In various embodiments, firing members, (e.g., I-beams or E-beams) can be constructed to have complex 3D printed geometries incorporated into the main body, which can act as a spring and allow the upper cam portion to flex and move with the anvil ledge to an angle of reduced or least resistance. Such geometric complex printed structures allow for metamaterial behaviors. For example, a metal I-beam could have portions that act as a solid metal structure and alternative portions having geometries that are designed to allow for greater bending and/or stretching to permit the I-beam to focus its deflection in a location and/or orientation to align the I-beam to the use and/or load. Exemplary embodiments of such !-beams are discussed in greater detail below. FIG.29depicts a firing member44000comprising a body portion44100, a pair of upper cam members44140extending laterally from both sides of the body portion44100, and a pair of lower cam members44150extending laterally from both sides of the body portion44100. The upper cam members44140are configured to cammingly engage an upper jaw, or anvil, of an end effector during a firing stroke, and the lower cam members44150are configured to cammingly engage a lower jaw, or elongate channel of the end effector during the firing stroke. The elongate channel is configured to receive a staple cartridge including staples that can be ejected when the firing member44000is advanced within the staple cartridge. Exemplary jaws, anvil, and staple cartridges for use with the firing member44000are further described herein. Further to the above, the body portion44100comprises a longitudinal opening44110extending through the body portion44100and defining a longitudinal axis LA. The body portion44100further comprises a distal nose portion44130extending distally from the body portion44100. The longitudinal opening44110is configured to receive a rotary firing driver, such as firing screw261(see, e.g.FIG.16) described above. The body portion44100further comprises a cutout region44120configured to receive a firing drive nut44200. The firing drive nut44200is configured to threadably engage the rotary firing driver to convert rotary motion of the rotary firing driver into translation of the firing member44000. The firing drive nut44200comprise a pair of laterally-extending members44210that extend from both sides of the firing drive nut44200. The pair of laterally-extending members44210are aligned with the pair of lower cam members44150. As such, the cam members44210,44150cooperate to cammingly engage the lower jaw of the end effector during the firing stroke. Further to the above, the firing member44000further comprises flexible portions44160positioned intermediate the body portion44100and the pair of upper cam members44140. In other words, the flexible portions44160attach at least a portion of the upper cam members44140to the body portion44100. As can be seen inFIG.31, the flexible portions44160comprise a three-dimensional lattice comprising an array of cavities, gaps, and/or cutouts. The array of cavities form a plurality of arcuate bars44162arrange in an array. The flexible portion44160comprises an overall cross-sectional density that is reduced compared to the adjacent upper cam member44140and the body portion44100. As such, the flexible portions44160can flex, bend, and/or deflect a greater amount than the adjacent upper cam member44140and the body portion44100. As can be seen inFIG.31, the arcuate bars44162and corresponding cutout regions are symmetrical about the body portion44100. However, other embodiments are envisioned where the arcuate bars44162are of varying shapes and sizes on the same side and/or or on opposite sides of the body portion44100. In certain instances, the array of cavities can form linear bars, for example. In at least one embodiment, the flexible portion44160comprises a three-dimensional honeycomb lattice, for example. The three-dimensional lattice of the flexible portions44160can have a reduced density in comparison to adjacent portions. Moreover, the flexible portions44160can have a significantly reduced infill percentage in comparison to adjacent portions. Further to the above, as can be seen inFIG.31, the flexible portions44160extend longitudinally along only a portion of the upper cam members44140from the distal end of the upper cam members44140and terminate in an intermediate portion of the upper cam members44140. As such, the distal end of the upper cam members44140is more flexible than the proximal end of the upper cam members44140. Other embodiments are envisioned where the flexible members44160extend along the entire length of the upper cam members44140and/or only at the proximal end of the upper cam members44140. Further still, other embodiments are envisioned where the flexible portions44160are in the middle of the upper cam members44140with more rigid portions at the proximal and distal ends. Further to the above, in at least one embodiment, the firing member44000may be constructed using a 3D printing process. Infill and solid wall parts are traditionally used to fabricate objects that are lightweight and strong. 3D printed parts are manufactured with a specific infill percentage. The printing process uses a crosshatch or other pattern for interior surfaces to form cells within the infill portion of the 3D printed part. The density of this pattern is referred to as the infill percentage. For example, it is common to have 1-2 mm thick walls, and to have 25-35% of the part solid inside of the walls. When building parts with powder based processes, such as 3D printing, it is important to note that powder must have escape holes to ensure powder reclamation after the part is fabricated. Infill for parts can be 2D like a honeycomb, or 3D like a gyroid. Different patterns have different strength profiles. For example, patterns with larger cells can be more flexible than patterns with smaller cells. Due to the freedom of geometry, the geometry can be variably thickened and thinned to ensure that flexion can occur at a desired location and a desired amount. Different geometries and infill percentages could be used at different locations in the firing member44000to achieve different degrees of deformation and/or predispositions to different directions of deformation. In certain instances, the leading end of the upper cam portion44140can have a different infill percentage or infill matrix/geometry than adjacent portions of the firing member44000to maintaining the rigidity of the proximal end of the upper cam member44140, as depicted inFIG.31. An increased deflection of the leading edge of the upper cam member44140can facilitate alignment of the upper cam member44140with the anvil ledge at the outset of the firing motion, which can avoid jamming or binding of the firing member in certain instances, such as when thick and/or tough tissue is clamped between the jaws. Other embodiments are envisioned where the middle of the upper cam member44140is flexible with both of the ends more rigid. As such, by varying the firing member geometry with 3D printing, the location and amount of flexion can be controlled based on the amount of force anticipated. FIGS.32and33depict a firing member45000comprising a body portion45100, a pair of upper cam members45140extending laterally from both sides of the body portion45100, and a pair of lower cam members45150extending laterally from both sides of the body portion45100. The upper cam members45140are configured to cammingly engage an upper jaw, or anvil, of an end effector during a firing stroke, and the lower cam members45150are configured to cammingly engage a lower jaw, or elongate channel of the end effector during the firing stroke. The elongate channel is configured to receive a staple cartridge including staples that can be ejected when the firing member44000is advanced within the staple cartridge. Exemplary jaws, anvil, and staple cartridges for use with the firing member45000are further described herein. Further to the above, the body portion45100comprises a longitudinal opening45110extending through the body portion45100, similar to the longitudinal opening44110(seeFIG.29). The longitudinal opening45110is configured to receive a rotary firing driver, such as firing screw261(see, e.g.FIG.16) described above. The body portion45100further comprises a distal nose portion45130extending distally from the body portion45100. The body portion45100further comprises a cutout region45120configured to receive a firing drive nut45200. The firing drive nut45200is configured to threadably engage the rotary firing driver to convert rotary motion of the rotary firing driver into translation of the firing member45000. The firing drive nut45200comprise a pair of laterally-extending cam members45210that extend from both sides of the firing drive nut45200. The pair of laterally-extending cam members45210are aligned with the pair of lower cam members45150. As such, the cam members45210,45150cooperate to cammingly engage the lower jaw of the end effector during the firing stroke. Further to the above, the firing member45000further comprises a flexible portion45160positioned intermediate the upper cam members45140and the lower cam members45150,45210. The flexible portion45160comprises a first plurality of arcuate slots45170extending laterally through the body portion45100, and a second plurality of arcuate slots45180extending laterally through the body portion45100. In the illustrated embodiment, the first plurality of arcuate slots45170are curved in a direction which resembles a backward C-shape, and the second plurality of arcuate slots are curved in the opposite direction which resembles a forward C-shape. However, other embodiments are envisioned with different curvatures or combination of curvatures for the arcuate slots45170. Further, in the illustrated embodiment five first arcuate slots45170and five second arcuate slots45180are depicted, however, other embodiments are envisioned with more or less than five arcuate slots for each of the first plurality or arcuate slots45170and each of the second plurality of arcuate slots45180. In any event, the body portion45100further comprises a first cutout region45175on its distal end that is defined by the first plurality of arcuate slots45170, and a second cutout region45185on its proximal end that is defined by the second plurality of arcuate slots45180. The arcuate slots45170,45180and the cutout regions45175,45185permit the firing member45000to flex and/or deflect when a load is applied to the firing member45000, as discussed in greater detail below. Referring primarily toFIG.33, an anvil channel or anvil ledge45300and an elongate channel45400for receiving a staple cartridge are depicted in dashed lines for the purpose of simplicity. In use, when the firing member45000is driven within an end effector, the upper cam members45140are configured to cammingly engage the anvil (i.e., ride along the anvil ledge45300) during the firing stroke. Further, the lower cam members45150,45210are configured to cammingly engage the bottom of the elongate channel45400during the firing stroke. During the firing stroke of the firing member45000, the upper cam members45140may experience a lateral force F applied by the anvil ledge45300when the anvil ledge45300moves away from the elongate channel45400. For example, the lateral force F may be due to clamping of patient tissue, firing of the staples, or cutting of the patient tissue. In at least one embodiment, the lateral force F may be applied to the upper cam members45150upon entry into the anvil channel, for example. In any event, the firing member45000is configured to flex and/or deflect due to the flexible portion45160during the firing stroke. Specifically, inFIG.32the firing member45000is in a relaxed state corresponding to an unloaded configuration, and inFIG.33the firing member45000is in an unrelaxed, or deflected state corresponding to a loaded configuration. Further to the above, due to the lateral force F applied to the upper cam members45140, the upper cam members45140rotate in a clockwise direction which causes the flexible portion45160and the body portion45100to flex and/or deflect to enable the firing member45000to change shape based on the load applied. Specifically, the first plurality of arcuate slots45170are configured to stretch and the second plurality of arcuate slots45180are configured to compress when the lateral force F is applied. Moreover, the first cutout region45175elongates and the second cutout region45185compresses when the lateral force F is applied. As such, the firing member body45100can flex and/or deflect to accommodate the lateral force F. Further to the above, during use, the upper cam members45140are configured to ride along the anvil ledge45300within a longitudinal anvil slot. Upon initial entry of the upper cam members45140into the anvil slot, the upper cam members45140may be misaligned due to the varying amounts of tissue (i.e., thick and thin tissue) grasped between the jaws. As such, the flexible portion45160permits the upper cam members45140to flex and/or deflect to properly align the upper cam members45140with the anvil slot, for example. Further, the varying amounts of tissue grasped between the jaws may cause the anvil ledges45300to move away from the elongate channel45400during a firing stroke of the firing member45000. As such, the upper cam members45140may become misaligned with the anvil slot during firing. However, the flexible portion45160permits the upper cam members45140to flex and/or deflect to compensate for the varying amounts of tissue to prevent the upper cam members45140from jamming within the anvil slot when the upper cam members45140are not properly aligned within the anvil slot. Further to the above, in at least one embodiment, the firing member45000can comprise a longitudinal slot extending through the flexible portion45160to permit one lateral side of the firing member45000to flex at least partially independent of another lateral side of the firing member45000. The longitudinal slot may be similar to longitudinal slot46170(seeFIG.34) discussed in greater detail below, for example. FIGS.34-36depict a firing member46000comprising a body portion46100, a pair of upper cam members46140extending laterally from both sides of the body portion46100, and a pair of lower cam members46150extending laterally from both sides of the body portion46100. The upper cam members46140are configured to cammingly engage an upper jaw, or anvil, of an end effector during a firing stroke, and the lower cam members46150are configured to cammingly engage a lower jaw, or elongate channel of the end effector during the firing stroke. The elongate channel is configured to receive a staple cartridge including staples that can be ejected when the firing member46000is advanced within the staple cartridge. Exemplary jaws, anvil, and staple cartridges for use with the firing member46000are further described herein. Further to the above, the body portion46100comprises a longitudinal opening46110extending through the body portion46100and defining a longitudinal axis LA. The longitudinal opening46110is configured to receive a rotary firing driver, such as firing screw261(see, e.g.FIG.40) described above. The body portion46100further comprises a distal nose portion46130extending distally from the body portion46100. The body portion46100further comprises a cutout region46120configured to receive a firing drive nut46200. The firing drive nut46200is configured to threadably engage the rotary firing driver to convert rotary motion of the rotary firing driver into translation of the firing member46000. The firing drive nut46200comprise a pair of laterally-extending cam members46210that extend from both sides of the firing drive nut46200. The pair of laterally-extending cam members46210are aligned with the pair of lower cam members46150. As such, the cam members46210,46150cooperate to cammingly engage the lower jaw of the end effector during the firing stroke. Further to the above, the firing member46000further comprises a flexible portion, or lattice portion,46160positioned intermediate the upper cam members46150and the lower cam members46150. In the illustrated embodiment, the lattice portion46160is bifurcated by a longitudinal slot46170which extends parallel to the longitudinal axis LA. The longitudinal slot46170extends through the body portion46100from the proximal end to the distal end. As such, the lattice portion46160is divided into a first side46180and a second side46190. The first side46180of the lattice portion46160comprises a plurality of slots46182oriented transverse to the longitudinal axis LA in a first direction. The second side46190of the lattice portion46160comprises a plurality of slots46192oriented transverse to the longitudinal axis LA in a second direction that is opposite the first direction. The plurality of slots46182,46192reduce the overall cross-sectional density of the firing member46000within the lattice portion46160. In other words, the lattice portion46160is less dense (e.g. lower infill percentage) than the adjacent portions of the body portion46100of the firing member46000. Further, the longitudinal slot46170, which bifurcates the lattice portion46160, permits the first side46180of the lattice46160to slide past the second side46190of the lattice46160, and vice versa, and/or permits the first side46180of the lattice46160to stretch vertically while the second side46190is compressed vertically, or vice versa. Without the longitudinal slot46170, sliding and deflection of the first and second sides46180,46190relative to one another would be limited. Further to the above, the first side46180comprises a notch46185on the proximal end of the body portion46100, and the second side46190comprises a notch46195on the proximal end of the body portion46100. The notches46185,46195provide greater flexion and/or deflection of the proximal end of the body portion46100as compared to the distal end of the body portion46100. Moreover, in the illustrated embodiment, the notches46185,46195are positioned on the proximal end of the body portion46100. However, other embodiments are envisioned where the notches46185,46195are positioned on the distal end of the body portion46100for the opposite effect. Further still, other embodiments are envisioned with notches on the proximal and distal ends of the body portion46100, seeFIG.38and accompanying description below. In use, when the firing member46000is advanced into an end effector, the upper cam members46140engage an upper jaw, or anvil of the end effector, and the lower cam members46150,46210engage a lower jaw, or elongate channel of the end effector. As such, the lattice portion46160is configured to permit the upper cam members46140and the lower cam members46150,46210to flex and/or deflect relative to the body portion46100to accommodate lateral forces during the firing stroke. The body portion46100and the lattice portion46160can be constructed of varying geometries and materials to accommodate a desired stress profile within the firing member46000during the firing stroke. For example, the firing member46000can be constructed using 3D printing, or an equivalent process. In at least one embodiment, the body portion46100is 3D printed as a unitary piece with the body portion comprising a first material and the lattice portion46160comprising a second material that is different from the first material. Further, the first material may comprise a first density and the second material can comprise a second density that is different from the first density. Further to the above, 3D printing generally produces structures that have some amount of open space (i.e., they are not completely solid on a micro level). As discussed above, the 3D printing process uses a crosshatch or other pattern for interior surfaces housed within more solid wall structures. The density of this pattern within the solid walls is referred to as the infill percentage. The infill percentage can be varied throughout the 3D printing process to produce a component having different infill percentages for different portions of the component. If different infill portions comprise different infill percentages, they inherently comprise different densities on a micro level. In other words, the different infill portions can be varied to produce different micro densities within a component. Further to the above, other embodiments are envisioned where the infill percentage is uniform throughout the entire part. In such instances, flexibility can be built into the part from macro-geometry aspects, such as slots, cutouts, holes etc. upon which the 3D build is built around. For example, the firing member46000may comprise an entirely uniform infill percentage. In such an instance, the slots46182,46192define bar structures in between the slots46182,46192, and the bar structures would comprise the same infill percentage as the rest of the firing member46000, for example. FIG.37depicts a graphical representation47000of the forces imparted on the firing member46000during a firing stroke. In the illustrated embodiment, the larger the force exerted on the firing member46000the darker the shading. The forces are shown in the legend inFIG.37as pounds per square inch (PSI). In the illustrated embodiment, a 150 pound load on the distal end of the firing member46000resulted in 1 degree of bending during the finite element analysis simulation. FIGS.38and39depict a firing member48000similar in many aspects to the firing member46000and with the differences discussed herein. The firing member48000comprises a flexible portion, or lattice portion48160. The lattice portion48160is bifurcated by a longitudinal slot that divides the lattice portion48160into a first side48180and second side48190. The first side48180comprises a proximal notch48182defined in the proximal end of the firing member48000, and a distal notch48184defined in the distal end of the firing member48000. The notches48182and48184are V-shaped or triangular cutouts. The proximal notch48182is larger along the upper edge, while the distal notch48184is larger along the lower edge. The second side48190comprises proximal and distal notches that are opposite the proximal notch48182and the distal notch48184. As such, the first side48180of the lattice portion48160is a flipped mirror image of the second side48190of the lattice portion48160. Similar to the firing member46000, the firing member48000comprises a plurality of slots oriented in the lattice portion48160. Specifically, the first side48180comprises a plurality of slots48186oriented in a first direction transverse to longitudinal axis LA of the firing member48000. Further, the second side48190comprises a plurality of slots48196oriented transverse to the longitudinal axis LA in a second direction opposite the first direction. FIG.40depicts a model of a flexible portion49000configured for use with a firing member of a surgical instrument, such as those firing members described herein. The flexible portion49000is configured to flex front-to-back and side-to-side to accommodate a loading force on the firing member during a firing stroke. The flexible portions44160,45160,46160,48160described herein can be configured to flex as shown inFIG.40, resulting in front-to-back and side-to-side flexing of the I-beam as well. Embodiments are envisioned where the flexible portion49000is part of, or takes the place of, the flexible portions44160,45160,46160,48160in the firing members described herein. The flexible portion49000is configured to transition from a relaxed state49100(shown in phantom lines) to a flexed, or deflected state49100′ (shown in solid lines) when a force is imparted onto the flexible portion49000. In the illustrated embodiment, the force applied is imparted onto an upper member49100of the flexible member49000while a base49120of the flexible member49000is held stationary. The upper member49100and the base49120are connected by a first vertical member49130and a second vertical member49140which crisscross to form an X-configuration. In use, when a force is applied to the upper member49100, the upper member49100transitions to a deflected state49110′, the first vertical member49130transitions to a deflected state49130′, and the second vertical member49140transitions to a deflected state49140′. The first and second vertical members49130,49140can be deflected to accommodate various loads applied to the upper member49100. It should be appreciate that any of the discrete features of the flexible portions44160,45160,46160,48160,49000can be used in combination with each other. For example, the flexible portions44160positioned between the upper cam member44140and the body portion44100may be incorporated into the firing members45000,46000, and/or48000. Moreover, the flexible portions44160may be incorporated into any of the lower cam members of firing members44000,45000,46000,48000,49000to provide for greater flexion of the lower cam members in certain instances. 3D printing may be utilized in a similar approach for various instrument components described herein, among others. For example, to accommodate a rotary drive screw in an elongate channel of a surgical instrument, the elongate channel may comprise a distal support bearing or support washer to support the distal end of the rotary drive screw. In at least one embodiment, the distal support bearing could be 3D printed to include a compressible portion that, when compressed in a first direction expands in a second direction that is transverse to the first direction to increase the bearing surface between the distal support bearing and the rotary drive screw. As a result, the coupling between the rotary drive screw and the distal support bearing is improved in certain instances due to a decrease in the bearing loads achieved by increasing the bearing surface area. Channel retainers and various end effector components are subject to high deflection and longitudinal loads during operation of a surgical instrument. Standard materials for these components consist of aluminum and stainless steel which have limited stretch and deflection capabilities. For example, 250 to 300 pounds of force can be applied longitudinally to a channel retainer during a surgical actuation and an acceptable longitudinal flex can be less than 0.08 inches. A composite component can include different materials for different portions to obtain complex part geometries, such as interlocking features, alignment keyways, or open sliding passages, for example, with a first material (e.g. plastic) while also maintaining appropriate strength, stiffness, and/or rigidity with a second material (e.g. metal) to support the longitudinal stress and strain loads during a surgical actuation. Metal portion(s) in a composite component can be flexible in one plane but rigid or stiff in another. For example, metal portions can permit lateral flexing but limit longitudinal stretching. Moreover, plastic material can act as a gap filler and interlocking substance between the metal substrates, while also allowing feature-rich, complex geometries. For example, a low durometer or flexible material such as plastic may be used as a body portion for an end effector component. The plastic body portion can comprise metal substrate portions defined therein to bear the loading forces during operation while the plastic body provides keying and alignment features. Such a laminate component can be constructed with 3D printed plastic and metal substrate inserts. For example, a channel retainer for use with a surgical device can comprise a first metal substrate, a second metal substrate interlocking with the first metal substrate, and a plastic portion built around the first metal substrate and the second metal substrate. The channel retainer is positioned between a handle and an end effector of the surgical device. Further, the channel retainer can comprise alignment and connection features built into the plastic body to facilitate attachment to the surgical device. FIGS.41-43depict a channel retainer50000for use with a surgical instrument, such as those described herein. In various embodiments, the proximal end of the channel retainer50000can be connected to a handle and/or housing of a surgical instrument and the distal end of the channel retainer50000can be connected to an articulation joint and/or end effector of a surgical instrument. The channel retainer50000acts as a longitudinal spine portion of the surgical instrument in such instances. Further, the channel retainer50000can support articulation actuators, firing actuators, and/or closure actuators of the surgical instrument. In at least one embodiment, the channel retainer50000bears the load of a closure tube which surrounds the channel retainer50000. As the closure tube advances to effectuate an end effector, forces are exerted onto the channel retainer50000. As such, the channel retainer50000can stretch and deflect due to the loading forces exerted by the closure tube. Further to the above, the proximal end of the channel retainer50000comprises notches50130which facilitate attachment of the channel retainer50000to the handle and/or housing of a surgical instrument. The distal end of the channel retainer50000comprises notches50120which facilitate attachment of the channel retainer to an articulation joint and/or end effector of a surgical instrument. However, other embodiments are envisioned with different attachment features for connecting the channel retainer50000to the surgical instrument. Further to the above, the channel retainer50000comprises a body portion50100, first substrate portions50300, and second substrate portions50400. The channel retainer50000further comprises a longitudinal slot50110defined therein for receiving various actuators of a surgical instrument. For example, a firing member extending from a handle or housing of a surgical instrument can extend within the longitudinal slot50110. In any event, the longitudinal slot50110splits the channel retainer50000in half with the first and second substrate portion50300,50400positioned on each side of the slot50110(i.e., the channel retainer50000is symmetrical). In at least one embodiment, the body portion50100is 3D printed with the first and second substrate portions50300,50400defined therein. In other words, the body portion50100is built around the first and second substrate portions50300,50400. In at least one embodiment, the body portion50100is comprised of plastic and the substrate portions50300,50400are comprised of metal. The substrate portions50300,50400can be comprised of stamped metal plates, for example. Other embodiments are envisioned where the substrate portions50300,50400comprises materials that are more rigid and/or dense than the body portion50100, for example. As illustrated inFIG.43, the first substrate portions50300are positioned within the body portion50110at the proximal end. Each first substrate portion50300comprises a first lateral flange50310at its distal end. The first lateral flanges50310extend toward the longitudinal slot50110. The second substrate portions50400are positioned within the body portion50100and each comprises a first opening50410at their proximal end and a second opening50420at their distal end. The first and second substrates50300,50400are positioned such that the first opening50410receives the first lateral flange50310to operably connect the first substrate portion50200and the second substrate portion50400within the body portion50100. In other words, the first and second substrate portions50300,50400are at least partially embedded and/or encapsulated within the body portion50100. These substrates can form a multi-interlocking load sharing assembly comprised of stamped components within the 3D-printed assembly. In certain instances, interlocking of stamped components within a 3D-printed assembly can be utilized to combine components where injection molding is not a viable alternative due to the shrinking of the composite material over elongated metal components during a molding process, which can result in a buildup of internal stresses and shear features within the assembly. For example, elongate assemblies, such as channel retainers, for example, may be better suited to 3D printing around interlocking metal components. Further to the above, each of the first substrate portions50300comprise a second lateral flange50320positioned at their proximal end and extending away from the longitudinal slot50110. The second lateral flanges50320are built and/or embedded into the body portion50100such that they extend behind the proximal notches50310defined in the body portion50100. As such, the first substrate portions50300are at least partially restricted from moving longitudinally within the body portion50100due to their engagement with the proximal notches50310. Further, the alignment notches50310may be used to attach and align the channel retainer50000within a handle or housing of the surgical instrument. As such, the first substrate portions50300within the proximal end provide additional support to the channel retainer50000to facilitate attachment to a surgical instrument. Other embodiments are envisioned with the first substrate portions50300at both the proximal and distal ends to facilitate attachment to a surgical device. In at least one embodiment, the body portion50100comprises a keying feature, an alignment feature, and/or an interlocking feature for use with a surgical instrument. The first and second substrate portions50300,50400can comprise more rigid metallic materials to bear the loading and stretch forces that the channel retainer50000experiences during operation of the surgical instrument. Further to the above, the first substrate portion50300and/or the second substrate portion50400comprise flexible circuit boards and/or other integrated electronics supported or affixed thereto. During manufacture, the 3D printing material of the body portion50100can be overprinted around the substrate portions50300,50400without directly affixing the build material to the electronics of the substrate portions50300,50400. By preventing direct application of the 3D build material onto the substrate portions50300,50400, the risk of damage to the substrate portions50300,50400and their electronic components is reduced. For example, referring primarily toFIG.43, there are various gaps50500between the substrate portions50300,50400and the body portion50100. As such, the channel retainer50000is constructed such that at least portions of the substrate portions50300,50400are not 3D printed directly thereon. Electronic components can be positioned in locations that are not directly 3D printed on, which can inhibit heat transfer and/or inadvertent damage to the electronic components due to localized heat. However, other embodiments are envisioned where the substrate portions50300,50400are completely encapsulated and surrounded by the 3D build material of the body portion50100. As discussed above, the channel retainer50000may be constructed via 3D printing. For example, before the 3D build begins, metal substrates such as substrate portions50300, are introduced upon which the 3D plastic build will be attached. Partially through the 3D build, the build could be stopped with standing alignment features to permit the creation of a perimeter build flange. The perimeter build flange allows for the introduction of another mid-substance metallic support plate, or substrate portions50400, for example. In at least one embodiment, the substrate portions50300,50400can be aligned in such a manner as to have coupling plastic features (such as notches50130, for example) that prevent movement of the substrates50300,50400within the body portion50100while also preventing shear of the body portion50100. In at least one embodiment, the channel retainer50000is a sandwiched laminate comprised of metal plates with 3D plastic printed coupling and assembly features. The metal plates are capable of bearing the load and stretch properties and the 3D printed elements are configured to provide all the keying, aligning, lateral support, and interlocking features with adjacent systems. 3D printing a channel retainer in this manner enables complex plastic interface features to be affixed to load bearing metallic sub-frames within and around the 3D built part. Further to the above, a steel stamped part could have a lateral flange bend in both ends for affixing to an elongate shaft and/or an articulation joint of a surgical instrument. The flanges could be laid into the 3D printer with the flanges away from the printing head path. The 3D build is then continued to form the rest of the channel retainer. As such, the lateral flange bends extend from the 3D printed channel retainer for attachment to the surgical instrument. In other words, the lateral flange bends are not overprinted with 3D printing material, extend from the 3D printed material, and are attachable to the surgical instrument. Further to the above, other embodiments are envisioned with a 3D printed laminate construction comprising a plastic body and metal substrates for various end effector components. For example, a staple cartridge, an elongate channel configured to receive a staple cartridge, and/or an anvil, could be constructed as a 3D printed laminate with plastic and metallic materials. As such, embodiments are envisioned where other end effector components utilize a plastic body for all of the keying and alignment features while the metal substrates bear the stretch and deflection loads during operation. Further to the above, with traditional insert molded parts creating undercuts, interior voids, interior spaces, and/or features transverse to the parting line of the mold (.e. more than 3 degrees from the parting axis of the mold) may be difficult and costly to manufacture in certain instances. The 3D-printed plastic body discussed above, can comprise undercuts, interior voids, and/or transverse alignment features for connecting components, for example. FIGS.44and45depict a surgical instrument51000comprising a firing bar support51020, a firing bar51010, and an over-molded sleeve51030. The firing bar support51020comprises two lateral plates51022,51024positioned on both sides of the firing bar51010. In the illustrated embodiment, the firing bar51010comprises a laminate firing bar constructed of several layers. Other embodiments are envisioned where the firing bar is a one-piece unitary structure. In any event, the firing bar support51020prevents bucking of the firing bar51010during firing of the firing bar51010and/or articulation of the end effector51000. In certain instances, the firing bar support51020may be identical to the firing bar support disclosed in U.S. patent application Ser. No. 15/635,808 filed on Jun. 28, 2017, the entirety of which is incorporated by reference herein. Further, the firing bar support51020comprises a flexible portion51040positioned in an articulation joint of the surgical instrument51000. Specifically,FIG.44illustrates the surgical instrument51000in an unarticulated orientation andFIG.45illustrates the surgical instrument51000in an articulated configuration. The firing bar support51020is defined within the over-molded sleeve51030that extends along the articulation joint of the surgical instrument51000. In other words, the over-molded sleeve51030encompasses and/or encapsulates the firing bar support51020therein. In at least one embodiment, the over-molded sleeve51030may be a plastic 3D printed material built around the firing bar support51020to embed and/or encapsulate the firing bar support51020therein. As such, the over-molded sleeve51030and the firing bar support51020comprise a substantially unitary piece. Further, the unitary piece formed of the over-molded sleeve51030and the firing bar support51030comprises a longitudinal slot51032defined therein. The longitudinal slot51032is configured to receiving the firing bar51010to permit translation of the firing member51010therein. FIG.46depicts an anvil52000for use with a surgical instrument, such as those described herein. The anvil52000comprises a tissue contacting surface52020and a longitudinal slot52030for receiving a portion of a firing member. The anvil52000further comprises an anvil slot52040extending longitudinally along at least a portion of the anvil52000. In the illustrated embodiment, the anvil slot52040is plus-shaped, however, other embodiments are envisioned where the anvil slot52040is T-shaped with a flat top portion. The reader will appreciate that alternative geometries and shapes for the anvil slot52040are contemplated. In any event, the anvil52000comprises a compliant portion52050extending longitudinally along at least a portion of the anvil slot52040. In the illustrated embodiment, the compliant portion52050is positioned around the perimeter of the anvil slot52040on all sides. However, other embodiments are envisioned where the compliant portion52050resides solely on a pair of anvil slot ledges52060of the anvil52000. In at least one embodiment, the compliant portion52050comprises a more compressible material than the remainder of the anvil52000. For example, the compliant portion52050can comprise a material that is less dense or softer (i.e., a smaller number on Mohs hardness scale) than the remainder of anvil52000material. In at least one embodiment, the compliant portion52050can be comprised of brass or bronze and the remainder of the anvil52000can be comprised of stainless steel. In any event, the upper pins or upper cam members of a firing member (i.e., an I-beam or E-beam) can ride along the compliant portion52050during firing. As such, the body of the anvil52000is more rigid with the anvil slot52040being softer and/or more compliant to facilitate more give to the firing member during firing. Further, the compliant portion52050may be smoother than the remainder of the anvil52000to further facilitate sliding of the upper pins of the firing member within the anvil slot52040. Further to the above, the anvil52000may be constructed using 3D printing to position the compliant portion52050within the body of the anvil52000. For example, the 3D printer could begin by building up stainless steel from the tissue contacting surface52020upward. The 3D build could be stopped to insert the compliant member52050, and then the build continued to encapsulate the compliant member52050within the stainless steel 3D print material of the anvil52000. As such, the compliant member52050and the anvil52000can be 3D printed to produce a substantially unitary piece having two different materials. Other embodiments are envisioned with more than two materials 3D printed into the anvil52000. Various aspects of the subject matter described herein are set out in the following examples. Example 1—A firing member for use with a surgical instrument comprising an anvil and an elongate channel configured to receive a staple cartridge. The firing member comprises a body portion configured to be driven through a firing stroke, a first cam member extending laterally from the body portion and configured to cammingly engage the anvil during the firing stroke, a second cam member extending laterally from the body portion and configured to cammingly engage the elongate channel during the firing stroke, and a lattice portion comprising a pattern of spaces formed in the firing member. The lattice portion is configured to flex more readily from a load during the firing stroke than adjacent portions of the firing member. Example 2—The firing member of Example 1, wherein the lattice portion is positioned intermediate the first cam member and the second cam member. Example 3—The firing member of Examples 1 or 2, further comprising a longitudinal slot extending longitudinally through the firing member, wherein the longitudinal slot bifurcates the lattice portion into a first portion on a first side of the longitudinal slot and a second portion on a second side of the longitudinal slot, and wherein the lattice portion is configured to deflect in opposing directions on opposite sides of the longitudinal slot. Example 4—The firing member of Example 3, wherein the pattern of spaces comprises a first plurality of slots in the first portion and a second plurality of slots in the second portion. Example 5—The firing member of Example 4, wherein the first plurality of slots are oriented in a first direction, and wherein the second plurality of slots are oriented in a second direction opposite the first direction. Example 6—The firing member of Examples 4 or 5, wherein the first plurality of slots are parallel to one another, and wherein the second plurality of slots are parallel to one another. Example 7—The firing member of Examples 1, 2, 3, 4, 5, or 6, wherein the lattice portion connects at least a portion of the first cam member to the body portion. Example 8—The firing member of Examples 1, 2, 3, 4, 5, 6, or 7, wherein the pattern of spaces define a plurality of arcuate bars connecting the first cam member and the body portion. Example 9—The firing member of Example 8, wherein the plurality of arcuate bars are arranged in an array. Example 10—The firing member of Examples 1, 2, 3, 4, 5, 6, 7, 8, or 9, wherein the pattern of spaces comprises an array of crisscrossing diagonal slots. Example 11—The firing member of Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, wherein the lattice portion is less rigid than the first cam member and the body portion. Example 12—An end effector comprising an anvil, an elongate channel configured to receive a staple cartridge, and a firing member. The firing member comprises a body portion, a first cam member extending laterally from the body portion and configured to cammingly engage the anvil during a firing stroke of the firing member, a second cam member extending laterally from the body portion and configured to cammingly engage the elongate channel during the firing stroke, and a flexible portion positioned intermediate the first cam member and the body portion. The flexible portion comprises a three-dimensional lattice comprising an array of cavities. Example 13—The end effector of Example 12, wherein the array of cavities define a plurality of arcuate bars. Example 14—The end effector of Examples 12 or 13, wherein the flexible portion comprises a first rigidity, wherein the body portion and the first cam member comprise a second rigidity, and wherein the first rigidity and the second rigidity are different. Example 15—A firing member for use with a surgical instrument comprising a first jaw and a second jaw. The firing member comprises a body portion configured to move longitudinally through a firing stroke, a first cam member extending laterally from the body portion and configured to cammingly engage the first jaw during the firing stroke, a second cam member extending laterally from the body portion and configured to cammingly engage the second jaw during the firing stroke, and a low density portion comprising a flexible lattice configured to flex more readily from a load during the firing stroke than adjacent portions of the firing member. Example 16—The firing member of Example 15, wherein the flexible lattice deflects a first amount when the first cam member is under the load, wherein the body portion adjacent the flexible lattice deflects a second amount when the first cam member is under the load, and wherein the first amount is greater than the second amount. Example 17—The firing member of Examples 15 or 16, wherein the body portion comprises a first rigidity, wherein the flexible lattice comprises a second rigidity, and wherein the first rigidity and the second rigidity are different. Example 18—The firing member of Examples 15, 16, or 17, wherein the flexible lattice comprises a plurality of slots arranged in a pattern and defined in the body portion. Example 19—The firing member of Examples 15, 16, 17, or 18, wherein the body portion comprises a first infill percentage, wherein the low density portion comprises a second infill percentage, and wherein the first infill percentage and the second infill percentage are different. Example 20—The firing member of Examples 15, 16, 17, 18, or 19, further comprising a longitudinal slot extending longitudinally through the firing member, wherein the longitudinal slot bifurcates the flexible lattice into a first portion on a first side of the longitudinal slot and a second portion on a second side of the longitudinal slot. Example 21—The firing member of Example 20, wherein the first portion comprises a plurality of slots oriented in a first direction and the second portion comprises a plurality of slots oriented in a second direction that is opposite the first direction. Example 22—A firing member for use with a surgical instrument comprising an anvil and an elongate channel configured to receive a staple cartridge, wherein the firing member comprises a body portion configured to be driven through a firing stroke, a first cam member extending laterally from the body portion and configured to cammingly engage the anvil during the firing stroke, a second cam member extending laterally from the body portion and configured to cammingly engage the elongate channel during the firing stroke, and a flexible portion. The flexible portion comprises a pattern of spaces formed in the firing member. The flexible portion is configured to flex more readily from a load during the firing stroke than adjacent less flexible portions of the firing member. The flexible portion is the same material as the adjacent less flexible portions. Example 23—A channel retainer for use with a surgical device. The channel retainer is positionable between a handle and an end effector of the surgical device. The channel retainer comprises a proximal end, a distal end, a plastic body extending from the proximal end to the distal end, a first metal substrate positioned within the plastic body, and a second metal substrate positioned within the plastic body. The first metal substrate comprises a lateral flange. The second metal substrate comprises an opening. The lateral flange is positioned within the opening to operably connect the first metal substrate and the second metal substrate within the plastic body. Example 24—The channel retainer of Example 23, wherein the first metal substrate is positioned at the proximal end of the channel retainer, and wherein the proximal end of the channel retainer is configured to be attached to the handle of the surgical device. Example 25—The channel retainer of Examples 23 or 24, wherein the plastic body comprises an alignment notch, and wherein the first metal substrate comprises another lateral flange embedded in the plastic body proximal to the alignment notch. Example 26—The channel retainer of Examples 23, 24, or 25, wherein at least one of the first metal substrate and the second metal substrate comprises a stamped metal component. Example 27—The channel retainer of Examples 23, 24, 25, or 26, wherein the plastic body is printed on the first metal substrate and the second metal substrate. Example 28—The channel retainer of Examples 23, 24, 25, 26, or 27, wherein the plastic body comprises one of a group consisting of a keying feature, an alignment feature, and an interlocking feature for connection with the surgical device. Example 29—The channel retainer of Examples 23, 24, 25, 26, 27, or 28, wherein at least one of the first metal substrate and the second metal substrate comprises a flexible circuit board. Example 30—A channel retainer for use with a surgical device. The channel retainer comprises a proximal end, a distal end, a first metal substrate, a second metal substrate interlocking with the first metal substrate, and a plastic portion extending from the proximal end to the distal end. The plastic portion is built around the first metal substrate and the second metal substrate. Example 31—The channel retainer of Example 30, wherein the first metal substrate comprises a flange embedded in an alignment portion of the plastic portion, and wherein the alignment portion is configured to attach the plastic portion to the surgical device. Example 32—The channel retainer of Examples 30 or 31, wherein the plastic portion comprises an alignment notch, and wherein the first metal substrate comprises a lateral flange embedded in the plastic portion proximal to the alignment notch. Example 33—The channel retainer of Examples 30, 31, or 32, wherein at least one of the first metal substrate and the second metal substrate comprises a stamped metal component. Example 34—The channel retainer of Examples 30, 31, 32, or 33, wherein the plastic portion is printed on the first metal substrate and the second metal substrate. Example 35—The channel retainer of Examples 30, 31, 32, 33, or 34, wherein the plastic portion comprises one of a group consisting of a keying feature, an aligning feature, and an interlocking feature for connection with the surgical device. Example 36—The channel retainer of Examples 30, 31, 32, 33, 34, or 35, wherein at least one of the first metal substrate and the second metal substrate comprises a flexible circuit board. Example 37—An end effector component for use with a surgical stapling device. The end effector component comprises a plastic body comprising alignment features. The end effector component further comprises a first metal substrate at least partially surrounded by the plastic body. The end effector component further comprises a second metal substrate at least partially surrounded by the plastic body. The first metal substrate and the second metal substrate comprise substrate interlocking features embedded within the plastic body. Example 38—The end effector component of Example 37, wherein the first metal substrate comprise a lateral flange, wherein the second metal substrate comprises an opening, and wherein the lateral flange is positioned within the opening and surrounded by the plastic body. Example 39—The end effector component of Examples 37 or 38, wherein the alignment features comprise notches at a proximal and a distal end of the plastic body, and wherein the notches facilitate attachment and alignment of the end effector component to a handle and an end effector of the surgical stapling device. Example 40—The end effector component of Examples 37, 38, or 39, wherein the end effector component comprises an elongate channel configured to receive a staple cartridge. Example 41—The end effector component of Examples 37, 38, 39, or 40, wherein at least one of the first metal substrate and the second metal substrate comprises a flexible circuit board. Example 42—The end effector component of Examples 37, 38, 39, 40, or 41 wherein the plastic body comprises an interior void, and wherein the interior void is completely surrounded by the plastic body. Example 43—The end effector component of Examples 37, 38, 39, 40, 41, or 42, wherein the plastic body comprises an undercut. Many of the surgical instrument systems described herein are motivated by an electric motor; however, the surgical instrument systems described herein can be motivated in any suitable manner. In various instances, the surgical instrument systems described herein can be motivated by a manually-operated trigger, for example. In certain instances, the motors disclosed herein may comprise a portion or portions of a robotically controlled system. Moreover, any of the end effectors and/or tool assemblies disclosed herein can be utilized with a robotic surgical instrument system. U.S. patent application Ser. No. 13/118,241, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, now U.S. Pat. No. 9,072,535, for example, discloses several examples of a robotic surgical instrument system in greater detail. The surgical instrument systems described herein have been described in connection with the deployment and deformation of staples; however, the embodiments described herein are not so limited. Various embodiments are envisioned which deploy fasteners other than staples, such as clamps or tacks, for example. Moreover, various embodiments are envisioned which utilize any suitable means for sealing tissue. For instance, an end effector in accordance with various embodiments can comprise electrodes configured to heat and seal the tissue. Also, for instance, an end effector in accordance with certain embodiments can apply vibrational energy to seal the tissue. The entire disclosures of: U.S. Pat. No. 5,403,312, entitled ELECTROSURGICAL HEMOSTATIC DEVICE, which issued on Apr. 4, 1995; U.S. Pat. No. 7,000,818, entitled SURGICAL STAPLING INSTRUMENT HAVING SEPARATE DISTINCT CLOSING AND FIRING SYSTEMS, which issued on Feb. 21, 2006; U.S. Pat. No. 7,422,139, entitled MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITH TACTILE POSITION FEEDBACK, which issued on Sep. 9, 2008; U.S. Pat. No. 7,464,849, entitled ELECTRO-MECHANICAL SURGICAL INSTRUMENT WITH CLOSURE SYSTEM AND ANVIL ALIGNMENT COMPONENTS, which issued on Dec. 16, 2008; U.S. Pat. No. 7,670,334, entitled SURGICAL INSTRUMENT HAVING AN ARTICULATING END EFFECTOR, which issued on Mar. 2, 2010; U.S. Pat. No. 7,753,245, entitled SURGICAL STAPLING INSTRUMENTS, which issued on Jul. 13, 2010; U.S. Pat. No. 8,393,514, entitled SELECTIVELY ORIENTABLE IMPLANTABLE FASTENER CARTRIDGE, which issued on Mar. 12, 2013; U.S. patent application Ser. No. 11/343,803, entitled SURGICAL INSTRUMENT HAVING RECORDING CAPABILITIES, now U.S. Pat. No. 7,845,537; U.S. patent application Ser. No. 12/031,573, entitled SURGICAL CUTTING AND FASTENING INSTRUMENT HAVING RF ELECTRODES, filed Feb. 14, 2008; U.S. patent application Ser. No. 12/031,873, entitled END EFFECTORS FOR A SURGICAL CUTTING AND STAPLING INSTRUMENT, filed Feb. 15, 2008, now U.S. Pat. No. 7,980,443; U.S. patent application Ser. No. 12/235,782, entitled MOTOR-DRIVEN SURGICAL CUTTING INSTRUMENT, now U.S. Pat. No. 8,210,411; U.S. patent application Ser. No. 12/249,117, entitled POWERED SURGICAL CUTTING AND STAPLING APPARATUS WITH MANUALLY RETRACTABLE FIRING SYSTEM, now U.S. Pat. No. 8,608,045; U.S. patent application Ser. No. 12/647,100, entitled MOTOR-DRIVEN SURGICAL CUTTING INSTRUMENT WITH ELECTRIC ACTUATOR DIRECTIONAL CONTROL ASSEMBLY, filed Dec. 24, 2009, now U.S. Pat. No. 8,220,688; U.S. patent application Ser. No. 12/893,461, entitled STAPLE CARTRIDGE, filed Sep. 29, 2012, now U.S. Pat. No. 8,733,613; U.S. patent application Ser. No. 13/036,647, entitled SURGICAL STAPLING INSTRUMENT, filed Feb. 28, 2011, now U.S. Pat. No. 8,561,870; U.S. patent application Ser. No. 13/118,241, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, now U.S. Pat. No. 9,072,535; U.S. patent application Ser. No. 13/524,049, entitled ARTICULATABLE SURGICAL INSTRUMENT COMPRISING A FIRING DRIVE, filed on Jun. 15, 2012, now U.S. Pat. No. 9,101,358; U.S. patent application Ser. No. 13/800,025, entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on Mar. 13, 2013, now U.S. Pat. No. 9,345,481; U.S. patent application Ser. No. 13/800,067, entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on Mar. 13, 2013, now U.S. Patent Application Publication No. 2014/0263552; U.S. Patent Application Publication No. 2007/0175955, entitled SURGICAL CUTTING AND FASTENING INSTRUMENT WITH CLOSURE TRIGGER LOCKING MECHANISM, filed Jan. 31, 2006; and U.S. Patent Application Publication No. 2010/0264194, entitled SURGICAL STAPLING INSTRUMENT WITH AN ARTICULATABLE END EFFECTOR, filed Apr. 22, 2010, now U.S. Pat. No. 8,308,040, are hereby incorporated by reference herein. Although various devices have been described herein in connection with certain embodiments, modifications and variations to those embodiments may be implemented. Particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, the particular features, structures, or characteristics illustrated or described in connection with one embodiment may be combined in whole or in part, with the features, structures or characteristics of one or more other embodiments without limitation. Also, where materials are disclosed for certain components, other materials may be used. Furthermore, according to various embodiments, a single component may be replaced by multiple components, and multiple components may be replaced by a single component, to perform a given function or functions. The foregoing description and following claims are intended to cover all such modification and variations. The devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. In either case, however, a device can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps including, but not limited to, the disassembly of the device, followed by cleaning or replacement of particular pieces of the device, and subsequent reassembly of the device. In particular, a reconditioning facility and/or surgical team can disassemble a device and, after cleaning and/or replacing particular parts of the device, the device can be reassembled for subsequent use. Those skilled in the art will appreciate that reconditioning of a device can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application. The devices disclosed herein may be processed before surgery. First, a new or used instrument may be obtained and, when necessary, cleaned. The instrument may then be sterilized. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and instrument may then be placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, and/or high-energy electrons. The radiation may kill bacteria on the instrument and in the container. The sterilized instrument may then be stored in the sterile container. The sealed container may keep the instrument sterile until it is opened in a medical facility. A device may also be sterilized using any other technique known in the art, including but not limited to beta radiation, gamma radiation, ethylene oxide, plasma peroxide, and/or steam. While this invention has been described as having exemplary designs, the present invention may be further modified within the spirit and scope of the disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated materials do not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.

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Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate various embodiments of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner. DETAILED DESCRIPTION Applicant of the present application also owns the following U.S. Patent Applications that were filed on even date herewith and which are each herein incorporated by reference in their respective entireties:U.S. patent application Ser. No. 17/246,010, entitled METHOD FOR OPERATING A SURGICAL INSTRUMENT INCLUDING SEGMENTED ELECTRODES;U.S. patent application Ser. No. 17/246,017, entitled STAPLE CARTRIDGE COMPRISING STAPLE DRIVERS AND STABILITY SUPPORTS;U.S. patent application Ser. No. 17/246,019, entitled STAPLE CARTRIDGE COMPRISING FORMATION SUPPORT FEATURES;U.S. patent application Ser. No. 17/246,022, entitled INTERCHANGEABLE END EFFECTOR RELOAD;U.S. patent application Ser. No. 17/246,040, entitled SURGICAL INSTRUMENT COMPRISING A CLOSURE BAR AND A FIRING BAR;U.S. patent application Ser. No. 17/246,055, entitled SURGICAL INSTRUMENT COMPRISING END EFFECTOR WITH LONGITUDINAL SEALING STEP;U.S. patent application Ser. No. 17/246,067, entitled SURGICAL INSTRUMENT COMPRISING END EFFECTOR WITH ENERGY SENSITIVE RESISTANCE ELEMENTS;U.S. patent application Ser. No. 14/246,073, entitled SURGICAL INSTRUMENT COMPRISING INDEPENDENTLY ACTIVATABLE SEGMENTED ELECTRODES;U.S. patent application Ser. No. 17/246,080, entitled SURGICAL SYSTEMS CONFIGURED TO CONTROL THERAPEUTIC ENERGY APPLICATION TO TISSUE BASED ON CARTRIDGE AND TISSUE PARAMETERS;U.S. patent application Ser. No. 17/246,089, entitled ELECTROSURGICAL TECHNIQUES FOR SEALING, SHORT CIRCUIT DETECTION, AND SYSTEM DETERMINATION OF POWER LEVEL;U.S. patent application Ser. No. 17/246,095, entitled ELECTROSURGICAL ADAPTATION TECHNIQUES OF ENERGY MODALITY FOR COMBINATION ELECTROSURGICAL INSTRUMENTS BASED ON SHORTING OR TISSUE IMPEDANCE IRREGULARITY;U.S. patent application Ser. No. 17/246,101, entitled SURGICAL STAPLE FOR USE WITH COMBINATION ELECTROSURGICAL INSTRUMENTS;U.S. patent application Ser. No. 17/246,101, entitled SURGICAL SYSTEMS CONFIGURED TO COOPERATIVELY CONTROL END EFFECTOR FUNCTION AND APPLICATION OF THERAPEUTIC ENERGY;U.S. patent application Ser. No. 17/246,134, entitled ARTICULATION SYSTEM FOR SURGICAL INSTRUMENT; andU.S. patent application Ser. No. 17/246,141, entitled SHAFT SYSTEM FOR SURGICAL INSTRUMENT. Applicant of the present application also owns the following U.S. Patent Applications that were filed on Feb. 26, 2021 and which are each herein incorporated by reference in their respective entireties:U.S. patent application Ser. No. 17/186,269, entitled METHOD OF POWERING AND COMMUNICATING WITH A STAPLE CARTRIDGE;U.S. patent application Ser. No. 17/186,273, entitled METHOD OF POWERING AND COMMUNICATING WITH A STAPLE CARTRIDGE;U.S. patent application Ser. No. 17/186,276, entitled ADJUSTABLE COMMUNICATION BASED ON AVAILABLE BANDWIDTH AND POWER CAPACITY;U.S. patent application Ser. No. 17/186,283, entitled ADJUSTMENT TO TRANSFER PARAMETERS TO IMPROVE AVAILABLE POWER;U.S. patent application Ser. No. 17/186,345, entitled MONITORING OF MANUFACTURING LIFE-CYCLE;U.S. patent application Ser. No. 17/186,350, entitled MONITORING OF MULTIPLE SENSORS OVER TIME TO DETECT MOVING CHARACTERISTICS OF TISSUE;U.S. patent application Ser. No. 17/186,353, entitled MONITORING OF INTERNAL SYSTEMS TO DETECT AND TRACK CARTRIDGE MOTION STATUS;U.S. patent application Ser. No. 17/186,357, entitled DISTAL COMMUNICATION ARRAY TO TUNE FREQUENCY OF RF SYSTEMS;U.S. patent application Ser. No. 17/186,364, entitled STAPLE CARTRIDGE COMPRISING A SENSOR ARRAY;U.S. patent application Ser. No. 17/186,373, entitled STAPLE CARTRIDGE COMPRISING A SENSING ARRAY AND A TEMPERATURE CONTROL SYSTEM;U.S. patent application Ser. No. 17/186,378, entitled STAPLE CARTRIDGE COMPRISING AN INFORMATION ACCESS CONTROL SYSTEM;U.S. patent application Ser. No. 17/186,407, entitled STAPLE CARTRIDGE COMPRISING A POWER MANAGEMENT CIRCUIT;U.S. patent application Ser. No. 17/186,421, entitled STAPLING INSTRUMENT COMPRISING A SEPARATE POWER ANTENNA AND A DATA TRANSFER ANTENNA;U.S. patent application Ser. No. 17/186,438, entitled SURGICAL INSTRUMENT SYSTEM COMPRISING A POWER TRANSFER COIL; andU.S. patent application Ser. No. 17/186,451, entitled STAPLING INSTRUMENT COMPRISING A SIGNAL ANTENNA. Applicant of the present application also owns the following U.S. Patent Applications that were filed on Oct. 29, 2020 and which are each herein incorporated by reference in their respective entireties:U.S. patent application Ser. No. 17/084,179, entitled SURGICAL INSTRUMENT COMPRISING A RELEASABLE CLOSURE DRIVE LOCK;U.S. patent application Ser. No. 17/084,190, entitled SURGICAL INSTRUMENT COMPRISING A STOWED CLOSURE ACTUATOR STOP;U.S. patent application Ser. No. 17/084,198, entitled SURGICAL INSTRUMENT COMPRISING AN INDICATOR WHICH INDICATES THAT AN ARTICULATION DRIVE IS ACTUATABLE;U.S. patent application Ser. No. 17/084,205, entitled SURGICAL INSTRUMENT COMPRISING AN ARTICULATION INDICATOR;U.S. patent application Ser. No. 17/084,258, entitled METHOD FOR OPERATING A SURGICAL INSTRUMENT;U.S. patent application Ser. No. 17/084,206, entitled SURGICAL INSTRUMENT COMPRISING AN ARTICULATION LOCK;U.S. patent application Ser. No. 17/084,215, entitled SURGICAL INSTRUMENT COMPRISING A JAW ALIGNMENT SYSTEM;U.S. patent application Ser. No. 17/084,229, entitled SURGICAL INSTRUMENT COMPRISING SEALABLE INTERFACE;U.S. patent application Ser. No. 17/084,180, entitled SURGICAL INSTRUMENT COMPRISING A LIMITED TRAVEL SWITCH;U.S. Design patent application Ser. No. 29/756,615, Applications entitled SURGICAL STAPLING ASSEMBLY;U.S. Design patent application Ser. No. 29/756,620, entitled SURGICAL STAPLING ASSEMBLY;U.S. patent application Ser. No. 17/084,188, entitled SURGICAL INSTRUMENT COMPRISING A STAGED VOLTAGE REGULATION START-UP SYSTEM; andU.S. patent application Ser. No. 17/084,193, entitled SURGICAL INSTRUMENT COMPRISING A SENSOR CONFIGURED TO SENSE WHETHER AN ARTICULATION DRIVE OF THE SURGICAL INSTRUMENT IS ACTUATABLE. Applicant of the present application also owns the following U.S. Patent Applications that were filed on Apr. 11, 2020 and which are each herein incorporated by reference in their respective entireties:U.S. patent application Ser. No. 16/846,303, entitled METHODS FOR STAPLING TISSUE USING A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2020/0345353;U.S. patent application Ser. No. 16/846,304, entitled ARTICULATION ACTUATORS FOR A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2020/0345354;U.S. patent application Ser. No. 16/846,305, entitled ARTICULATION DIRECTIONAL LIGHTS ON A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2020/0345446;U.S. patent application Ser. No. 16/846,307, entitled SHAFT ROTATION ACTUATOR ON A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2020/03453549;U.S. patent application Ser. No. 16/846,308, entitled ARTICULATION CONTROL MAPPING FOR A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2020/0345355;U.S. patent application Ser. No. 16/846,309, entitled INTELLIGENT FIRING ASSOCIATED WITH A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2020/0345356;U.S. patent application Ser. No. 16/846,310, entitled INTELLIGENT FIRING ASSOCIATED WITH A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2020/0345357;U.S. patent application Ser. No. 16/846,311, entitled ROTATABLE JAW TIP FOR A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2020/0345358;U.S. patent application Ser. No. 16/846,312, entitled TISSUE STOP FOR A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2020/0345359; andU.S. patent application Ser. No. 16/846,313, entitled ARTICULATION PIN FOR A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2020/0345360. The entire disclosure of U.S. Provisional Patent Application Ser. No. 62/840,715, entitled SURGICAL INSTRUMENT COMPRISING AN ADAPTIVE CONTROL SYSTEM, filed Apr. 30, 2019, is hereby incorporated by reference herein. Applicant of the present application owns the following U.S. Patent Applications that were filed on Feb. 21, 2019 and which are each herein incorporated by reference in their respective entireties:U.S. patent application Ser. No. 16/281,658, entitled METHODS FOR CONTROLLING A POWERED SURGICAL STAPLER THAT HAS SEPARATE ROTARY CLOSURE AND FIRING SYSTEMS, now U.S. Patent Application Publication No. 2019/0298350;U.S. patent application Ser. No. 16/281,670, entitled STAPLE CARTRIDGE COMPRISING A LOCKOUT KEY CONFIGURED TO LIFT A FIRING MEMBER, now U.S. Patent Application Publication No. 2019/0298340;U.S. patent application Ser. No. 16/281,675, entitled SURGICAL STAPLERS WITH ARRANGEMENTS FOR MAINTAINING A FIRING MEMBER THEREOF IN A LOCKED CONFIGURATION UNLESS A COMPATIBLE CARTRIDGE HAS BEEN INSTALLED THEREIN, now U.S. Patent Application Publication No. 2019/0298354;U.S. patent application Ser. No. 16/281,685, entitled SURGICAL INSTRUMENT COMPRISING CO-OPERATING LOCKOUT FEATURES, now U.S. Patent Application Publication No. 2019/0298341;U.S. patent application Ser. No. 16/281,693, entitled SURGICAL STAPLING ASSEMBLY COMPRISING A LOCKOUT AND AN EXTERIOR ACCESS ORIFICE TO PERMIT ARTIFICIAL UNLOCKING OF THE LOCKOUT, now U.S. Patent Application Publication No. 2019/0298342;U.S. patent application Ser. No. 16/281,704, entitled SURGICAL STAPLING DEVICES WITH FEATURES FOR BLOCKING ADVANCEMENT OF A CAMMING ASSEMBLY OF AN INCOMPATIBLE CARTRIDGE INSTALLED THEREIN, now U.S. Patent Application Publication No. 2019/0298356;U.S. patent application Ser. No. 16/281,707, entitled STAPLING INSTRUMENT COMPRISING A DEACTIVATABLE LOCKOUT, now U.S. Patent Application Publication No. 2019/0298347;U.S. patent application Ser. No. 16/281,741, entitled SURGICAL INSTRUMENT COMPRISING A JAW CLOSURE LOCKOUT, now U.S. Patent Application Publication No. 2019/0298357;U.S. patent application Ser. No. 16/281,762, entitled SURGICAL STAPLING DEVICES WITH CARTRIDGE COMPATIBLE CLOSURE AND FIRING LOCKOUT ARRANGEMENTS, now U.S. Patent Application Publication No. 2019/0298343;U.S. patent application Ser. No. 16/281,666, entitled SURGICAL STAPLING DEVICES WITH IMPROVED ROTARY DRIVEN CLOSURE SYSTEMS, now U.S. Patent Application Publication No. 2019/0298352;U.S. patent application Ser. No. 16/281,672, entitled SURGICAL STAPLING DEVICES WITH ASYMMETRIC CLOSURE FEATURES, now U.S. Patent Application Publication No. 2019/0298353;U.S. patent application Ser. No. 16/281,678, entitled ROTARY DRIVEN FIRING MEMBERS WITH DIFFERENT ANVIL AND CHANNEL ENGAGEMENT FEATURES, now U.S. Patent Application Publication No. 2019/0298355; andU.S. patent application Ser. No. 16/281,682, entitled SURGICAL STAPLING DEVICE WITH SEPARATE ROTARY DRIVEN CLOSURE AND FIRING SYSTEMS AND FIRING MEMBER THAT ENGAGES BOTH JAWS WHILE FIRING, now U.S. Patent Application Publication No. 2019/0298346. Applicant of the present application owns the following U.S. Provisional Patent Applications that were filed on Feb. 19, 2019 and which are each herein incorporated by reference in their respective entireties:U.S. Provisional Patent Application Ser. No. 62/807,310, entitled METHODS FOR CONTROLLING A POWERED SURGICAL STAPLER THAT HAS SEPARATE ROTARY CLOSURE AND FIRING SYSTEMS;U.S. Provisional Patent Application Ser. No. 62/807,319, entitled SURGICAL STAPLING DEVICES WITH IMPROVED LOCKOUT SYSTEMS; andU.S. Provisional Patent Application Ser. No. 62/807,309, entitled SURGICAL STAPLING DEVICES WITH IMPROVED ROTARY DRIVEN CLOSURE SYSTEMS. Applicant of the present application owns the following U.S. Provisional Patent Applications, filed on Mar. 28, 2018, each of which is herein incorporated by reference in its entirety:U.S. Provisional Patent Application Ser. No. 62/649,302, entitled INTERACTIVE SURGICAL SYSTEMS WITH ENCRYPTED COMMUNICATION CAPABILITIES;U.S. Provisional Patent Application Ser. No. 62/649,294, entitled DATA STRIPPING METHOD TO INTERROGATE PATIENT RECORDS AND CREATE ANONYMIZED RECORD;U.S. Provisional Patent Application Ser. No. 62/649,300, entitled SURGICAL HUB SITUATIONAL AWARENESS;U.S. Provisional Patent Application Ser. No. 62/649,309, entitled SURGICAL HUB SPATIAL AWARENESS TO DETERMINE DEVICES IN OPERATING THEATER;U.S. Provisional Patent Application Ser. No. 62/649,310, entitled COMPUTER IMPLEMENTED INTERACTIVE SURGICAL SYSTEMS;U.S. Provisional Patent Application Ser. No. 62/649,291, entitled USE OF LASER LIGHT AND RED-GREEN-BLUE COLORATION TO DETERMINE PROPERTIES OF BACK SCATTERED LIGHT;U.S. Provisional Patent Application Ser. No. 62/649,296, entitled ADAPTIVE CONTROL PROGRAM UPDATES FOR SURGICAL DEVICES;U.S. Provisional Patent Application Ser. No. 62/649,333, entitled CLOUD-BASED MEDICAL ANALYTICS FOR CUSTOMIZATION AND RECOMMENDATIONS TO A USER;U.S. Provisional Patent Application Ser. No. 62/649,327, entitled CLOUD-BASED MEDICAL ANALYTICS FOR SECURITY AND AUTHENTICATION TRENDS AND REACTIVE MEASURES;U.S. Provisional Patent Application Ser. No. 62/649,315, entitled DATA HANDLING AND PRIORITIZATION IN A CLOUD ANALYTICS NETWORK;U.S. Provisional Patent Application Ser. No. 62/649,313, entitled CLOUD INTERFACE FOR COUPLED SURGICAL DEVICES;U.S. Provisional Patent Application Ser. No. 62/649,320, entitled DRIVE ARRANGEMENTS FOR ROBOT-ASSISTED SURGICAL PLATFORMS;U.S. Provisional Patent Application Ser. No. 62/649,307, entitled AUTOMATIC TOOL ADJUSTMENTS FOR ROBOT-ASSISTED SURGICAL PLATFORMS; andU.S. Provisional Patent Application Ser. No. 62/649,323, entitled SENSING ARRANGEMENTS FOR ROBOT-ASSISTED SURGICAL PLATFORMS. Applicant of the present application owns the following U.S. Provisional Patent Application, filed on Mar. 30, 2018, which is herein incorporated by reference in its entirety:U.S. Provisional Patent Application Ser. No. 62/650,887, entitled SURGICAL SYSTEMS WITH OPTIMIZED SENSING CAPABILITIES. Applicant of the present application owns the following U.S. Patent Application, filed on Dec. 4, 2018, which is herein incorporated by reference in its entirety:U.S. patent application Ser. No. 16/209,423, entitled METHOD OF COMPRESSING TISSUE WITHIN A STAPLING DEVICE AND SIMULTANEOUSLY DISPLAYING THE LOCATION OF THE TISSUE WITHIN THE JAWS, now U.S. Patent Application Publication No. 2019/0200981. Applicant of the present application owns the following U.S. Patent Applications that were filed on Aug. 20, 2018 and which are each herein incorporated by reference in their respective entireties:U.S. patent application Ser. No. 16/105,101, entitled METHOD FOR FABRICATING SURGICAL STAPLER ANVILS, now U.S. Patent Application Publication No. 2020/0054323;U.S. patent application Ser. No. 16/105,183, entitled REINFORCED DEFORMABLE ANVIL TIP FOR SURGICAL STAPLER ANVIL, now U.S. Pat. No. 10,912,559;U.S. patent application Ser. No. 16/105,150, entitled SURGICAL STAPLER ANVILS WITH STAPLE DIRECTING PROTRUSIONS AND TISSUE STABILITY FEATURES, now U.S. Patent Application Publication No. 2020/0054326;U.S. patent application Ser. No. 16/105,098, entitled FABRICATING TECHNIQUES FOR SURGICAL STAPLER ANVILS, now U.S. Patent Application Publication No. 2020/0054322;U.S. patent application Ser. No. 16/105,140, entitled SURGICAL STAPLER ANVILS WITH TISSUE STOP FEATURES CONFIGURED TO AVOID TISSUE PINCH, now U.S. Pat. No. 10,779,821;U.S. patent application Ser. No. 16/105,081, entitled METHOD FOR OPERATING A POWERED ARTICULATABLE SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2020/0054320;U.S. patent application Ser. No. 16/105,094, entitled SURGICAL INSTRUMENTS WITH PROGRESSIVE JAW CLOSURE ARRANGEMENTS, now U.S. Patent Application Publication No. 2020/0054321;U.S. patent application Ser. No. 16/105,097, entitled POWERED SURGICAL INSTRUMENTS WITH CLUTCHING ARRANGEMENTS TO CONVERT LINEAR DRIVE MOTIONS TO ROTARY DRIVE MOTIONS, now U.S. Patent Application Publication No. 2020/0054328;U.S. patent application Ser. No. 16/105,104, entitled POWERED ARTICULATABLE SURGICAL INSTRUMENTS WITH CLUTCHING AND LOCKING ARRANGEMENTS FOR LINKING AN ARTICULATION DRIVE SYSTEM TO A FIRING DRIVE SYSTEM, now U.S. Pat. No. 10,842,492;U.S. patent application Ser. No. 16/105,119, entitled ARTICULATABLE MOTOR POWERED SURGICAL INSTRUMENTS WITH DEDICATED ARTICULATION MOTOR ARRANGEMENTS, now U.S. Patent Application Publication No. 2020/0054330;U.S. patent application Ser. No. 16/105,160, entitled SWITCHING ARRANGEMENTS FOR MOTOR POWERED ARTICULATABLE SURGICAL INSTRUMENTS, now U.S. Pat. No. 10,856,870; andU.S. Design patent application Ser. No. 29/660,252, entitled SURGICAL STAPLER ANVILS. Applicant of the present application owns the following U.S. Patent Applications and U.S. Patents that are each herein incorporated by reference in their respective entireties:U.S. patent application Ser. No. 15/386,185, entitled SURGICAL STAPLING INSTRUMENTS AND REPLACEABLE TOOL ASSEMBLIES THEREOF, now U.S. Pat. No. 10,639,035;U.S. patent application Ser. No. 15/386,230, entitled ARTICULATABLE SURGICAL STAPLING INSTRUMENTS, now U.S. Patent Application Publication No. 2018/0168649;U.S. patent application Ser. No. 15/386,221, entitled LOCKOUT ARRANGEMENTS FOR SURGICAL END EFFECTORS, now U.S. Pat. No. 10,835,247;U.S. patent application Ser. No. 15/386,209, entitled SURGICAL END EFFECTORS AND FIRING MEMBERS THEREOF, now U.S. Pat. No. 10,588,632;U.S. patent application Ser. No. 15/386,198, entitled LOCKOUT ARRANGEMENTS FOR SURGICAL END EFFECTORS AND REPLACEABLE TOOL ASSEMBLIES, now U.S. Pat. No. 10,610,224;U.S. patent application Ser. No. 15/386,240, entitled SURGICAL END EFFECTORS AND ADAPTABLE FIRING MEMBERS THEREFOR, now U.S. Patent Application Publication No. 2018/0168651;U.S. patent application Ser. No. 15/385,939, entitled STAPLE CARTRIDGES AND ARRANGEMENTS OF STAPLES AND STAPLE CAVITIES THEREIN, now U.S. Pat. No. 10,835,246;U.S. patent application Ser. No. 15/385,941, entitled SURGICAL TOOL ASSEMBLIES WITH CLUTCHING ARRANGEMENTS FOR SHIFTING BETWEEN CLOSURE SYSTEMS WITH CLOSURE STROKE REDUCTION FEATURES AND ARTICULATION AND FIRING SYSTEMS, now U.S. Pat. No. 10,736,629;U.S. patent application Ser. No. 15/385,943, entitled SURGICAL STAPLING INSTRUMENTS AND STAPLE-FORMING ANVILS, now U.S. Pat. No. 10,667,811;U.S. patent application Ser. No. 15/385,950, entitled SURGICAL TOOL ASSEMBLIES WITH CLOSURE STROKE REDUCTION FEATURES, now U.S. Pat. No. 10,588,630;U.S. patent application Ser. No. 15/385,945, entitled STAPLE CARTRIDGES AND ARRANGEMENTS OF STAPLES AND STAPLE CAVITIES THEREIN, now U.S. Pat. No. 10,893,864;U.S. patent application Ser. No. 15/385,946, entitled SURGICAL STAPLING INSTRUMENTS AND STAPLE-FORMING ANVILS, now U.S. Patent Application Publication No. 2018/0168633;U.S. patent application Ser. No. 15/385,951, entitled SURGICAL INSTRUMENTS WITH JAW OPENING FEATURES FOR INCREASING A JAW OPENING DISTANCE, now U.S. Pat. No. 10,568,626;U.S. patent application Ser. No. 15/385,953, entitled METHODS OF STAPLING TISSUE, now U.S. Pat. No. 10,675,026;U.S. patent application Ser. No. 15/385,954, entitled FIRING MEMBERS WITH NON-PARALLEL JAW ENGAGEMENT FEATURES FOR SURGICAL END EFFECTORS, now U.S. Pat. No. 10,624,635;U.S. patent application Ser. No. 15/385,955, entitled SURGICAL END EFFECTORS WITH EXPANDABLE TISSUE STOP ARRANGEMENTS, now U.S. Pat. No. 10,813,638;U.S. patent application Ser. No. 15/385,948, entitled SURGICAL STAPLING INSTRUMENTS AND STAPLE-FORMING ANVILS, now U.S. Patent Application Publication No. 2018/0168584;U.S. patent application Ser. No. 15/385,956, entitled SURGICAL INSTRUMENTS WITH POSITIVE JAW OPENING FEATURES, now U.S. Pat. No. 10,588,631;U.S. patent application Ser. No. 15/385,958, entitled SURGICAL INSTRUMENTS WITH LOCKOUT ARRANGEMENTS FOR PREVENTING FIRING SYSTEM ACTUATION UNLESS AN UNSPENT STAPLE CARTRIDGE IS PRESENT, now U.S. Pat. No. 10,639,034;U.S. patent application Ser. No. 15/385,947, entitled STAPLE CARTRIDGES AND ARRANGEMENTS OF STAPLES AND STAPLE CAVITIES THEREIN, now U.S. Pat. No. 10,568,625;U.S. patent application Ser. No. 15/385,896, entitled METHOD FOR RESETTING A FUSE OF A SURGICAL INSTRUMENT SHAFT, now U.S. Patent Application Publication No. 2018/0168597;U.S. patent application Ser. No. 15/385,898, entitled STAPLE-FORMING POCKET ARRANGEMENT TO ACCOMMODATE DIFFERENT TYPES OF STAPLES, now U.S. Pat. No. 10,537,325;U.S. patent application Ser. No. 15/385,899, entitled SURGICAL INSTRUMENT COMPRISING IMPROVED JAW CONTROL, now U.S. Pat. No. 10,758,229;U.S. patent application Ser. No. 15/385,901, entitled STAPLE CARTRIDGE AND STAPLE CARTRIDGE CHANNEL COMPRISING WINDOWS DEFINED THEREIN, now U.S. Pat. No. 10,667,809;U.S. patent application Ser. No. 15/385,902, entitled SURGICAL INSTRUMENT COMPRISING A CUTTING MEMBER, now U.S. Pat. No. 10,888,322;U.S. patent application Ser. No. 15/385,904, entitled STAPLE FIRING MEMBER COMPRISING A MISSING CARTRIDGE AND/OR SPENT CARTRIDGE LOCKOUT, now U.S. Pat. No. 10,881,401;U.S. patent application Ser. No. 15/385,905, entitled FIRING ASSEMBLY COMPRISING A LOCKOUT, now U.S. Pat. No. 10,695,055;U.S. patent application Ser. No. 15/385,907, entitled SURGICAL INSTRUMENT SYSTEM COMPRISING AN END EFFECTOR LOCKOUT AND A FIRING ASSEMBLY LOCKOUT, now U.S. Patent Application Publication No. 2018/0168608;U.S. patent application Ser. No. 15/385,908, entitled FIRING ASSEMBLY COMPRISING A FUSE, now U.S. Patent Application Publication No. 2018/0168609;U.S. patent application Ser. No. 15/385,909, entitled FIRING ASSEMBLY COMPRISING A MULTIPLE FAILED-STATE FUSE, now U.S. Patent Application Publication No. 2018/0168610;U.S. patent application Ser. No. 15/385,920, entitled STAPLE-FORMING POCKET ARRANGEMENTS, now U.S. Pat. No. 10,499,914;U.S. patent application Ser. No. 15/385,913, entitled ANVIL ARRANGEMENTS FOR SURGICAL STAPLERS, now U.S. Patent Application Publication No. 2018/0168614;U.S. patent application Ser. No. 15/385,914, entitled METHOD OF DEFORMING STAPLES FROM TWO DIFFERENT TYPES OF STAPLE CARTRIDGES WITH THE SAME SURGICAL STAPLING INSTRUMENT, now U.S. Patent Application Publication No. 2018/0168615;U.S. patent application Ser. No. 15/385,893, entitled BILATERALLY ASYMMETRIC STAPLE-FORMING POCKET PAIRS, now U.S. Pat. No. 10,682,138;U.S. patent application Ser. No. 15/385,929, entitled CLOSURE MEMBERS WITH CAM SURFACE ARRANGEMENTS FOR SURGICAL INSTRUMENTS WITH SEPARATE AND DISTINCT CLOSURE AND FIRING SYSTEMS, now U.S. Pat. No. 10,667,810;U.S. patent application Ser. No. 15/385,911, entitled SURGICAL STAPLERS WITH INDEPENDENTLY ACTUATABLE CLOSING AND FIRING SYSTEMS, now U.S. Pat. No. 10,448,950;U.S. patent application Ser. No. 15/385,927, entitled SURGICAL STAPLING INSTRUMENTS WITH SMART STAPLE CARTRIDGES, now U.S. Patent Application Publication No. 2018/0168625;U.S. patent application Ser. No. 15/385,917, entitled STAPLE CARTRIDGE COMPRISING STAPLES WITH DIFFERENT CLAMPING BREADTHS, now U.S. Patent Application Publication No. 2018/0168617;U.S. patent application Ser. No. 15/385,900, entitled STAPLE-FORMING POCKET ARRANGEMENTS COMPRISING PRIMARY SIDEWALLS AND POCKET SIDEWALLS, now U.S. Pat. No. 10,898,186;U.S. patent application Ser. No. 15/385,931, entitled NO-CARTRIDGE AND SPENT CARTRIDGE LOCKOUT ARRANGEMENTS FOR SURGICAL STAPLERS, now U.S. Patent Application Publication No. 2018/0168627;U.S. patent application Ser. No. 15/385,915, entitled FIRING MEMBER PIN ANGLE, now U.S. Pat. No. 10,779,823;U.S. patent application Ser. No. 15/385,897, entitled STAPLE-FORMING POCKET ARRANGEMENTS COMPRISING ZONED FORMING SURFACE GROOVES, now U.S. Patent Application Publication No. 2018/0168598;U.S. patent application Ser. No. 15/385,922, entitled SURGICAL INSTRUMENT WITH MULTIPLE FAILURE RESPONSE MODES, now U.S. Pat. No. 10,426,471;U.S. patent application Ser. No. 15/385,924, entitled SURGICAL INSTRUMENT WITH PRIMARY AND SAFETY PROCESSORS, now U.S. Pat. No. 10,758,230;U.S. patent application Ser. No. 15/385,910, entitled ANVIL HAVING A KNIFE SLOT WIDTH, now U.S. Pat. No. 10,485,543;U.S. patent application Ser. No. 15/385,903, entitled CLOSURE MEMBER ARRANGEMENTS FOR SURGICAL INSTRUMENTS, now U.S. Pat. No. 10,617,414;U.S. patent application Ser. No. 15/385,906, entitled FIRING MEMBER PIN CONFIGURATIONS, now U.S. Pat. No. 10,856,868;U.S. patent application Ser. No. 15/386,188, entitled STEPPED STAPLE CARTRIDGE WITH ASYMMETRICAL STAPLES, now U.S. Pat. No. 10,537,324;U.S. patent application Ser. No. 15/386,192, entitled STEPPED STAPLE CARTRIDGE WITH TISSUE RETENTION AND GAP SETTING FEATURES, now U.S. Pat. No. 10,687,810;U.S. patent application Ser. No. 15/386,206, entitled STAPLE CARTRIDGE WITH DEFORMABLE DRIVER RETENTION FEATURES, now U.S. Patent Application Publication No. 2018/0168586;U.S. patent application Ser. No. 15/386,226, entitled DURABILITY FEATURES FOR END EFFECTORS AND FIRING ASSEMBLIES OF SURGICAL STAPLING INSTRUMENTS, now U.S. Patent Application Publication No. 2018/0168648;U.S. patent application Ser. No. 15/386,222, entitled SURGICAL STAPLING INSTRUMENTS HAVING END EFFECTORS WITH POSITIVE OPENING FEATURES, now U.S. Patent Application Publication No. 2018/0168647;U.S. patent application Ser. No. 15/386,236, entitled CONNECTION PORTIONS FOR DEPOSABLE LOADING UNITS FOR SURGICAL STAPLING INSTRUMENTS, now U.S. Patent Application Publication No. 2018/0168650;U.S. patent application Ser. No. 15/385,887, entitled METHOD FOR ATTACHING A SHAFT ASSEMBLY TO A SURGICAL INSTRUMENT AND, ALTERNATIVELY, TO A SURGICAL ROBOT, now U.S. Pat. No. 10,835,245;U.S. patent application Ser. No. 15/385,889, entitled SHAFT ASSEMBLY COMPRISING A MANUALLY-OPERABLE RETRACTION SYSTEM FOR USE WITH A MOTORIZED SURGICAL INSTRUMENT SYSTEM, now U.S. Patent Application Publication No. 2018/0168590;U.S. patent application Ser. No. 15/385,890, entitled SHAFT ASSEMBLY COMPRISING SEPARATELY ACTUATABLE AND RETRACTABLE SYSTEMS, now U.S. Pat. No. 10,675,025;U.S. patent application Ser. No. 15/385,891, entitled SHAFT ASSEMBLY COMPRISING A CLUTCH CONFIGURED TO ADAPT THE OUTPUT OF A ROTARY FIRING MEMBER TO TWO DIFFERENT SYSTEMS, now U.S. Patent Application Publication No. 2018/0168592;U.S. patent application Ser. No. 15/385,892, entitled SURGICAL SYSTEM COMPRISING A FIRING MEMBER ROTATABLE INTO AN ARTICULATION STATE TO ARTICULATE AN END EFFECTOR OF THE SURGICAL SYSTEM, now U.S. Pat. No. 10,918,385;U.S. patent application Ser. No. 15/385,894, entitled SHAFT ASSEMBLY COMPRISING A LOCKOUT, now U.S. Pat. No. 10,492,785;U.S. patent application Ser. No. 15/385,895, entitled SHAFT ASSEMBLY COMPRISING FIRST AND SECOND ARTICULATION LOCKOUTS, now U.S. Pat. No. 10,542,982;U.S. patent application Ser. No. 15/385,916, entitled SURGICAL STAPLING SYSTEMS, now U.S. Patent Application Publication No. 2018/0168575;U.S. patent application Ser. No. 15/385,918, entitled SURGICAL STAPLING SYSTEMS, now U.S. Patent Application Publication No. 2018/0168618;U.S. patent application Ser. No. 15/385,919, entitled SURGICAL STAPLING SYSTEMS, now U.S. Patent Application Publication No. 2018/0168619;U.S. patent application Ser. No. 15/385,921, entitled SURGICAL STAPLE CARTRIDGE WITH MOVABLE CAMMING MEMBER CONFIGURED TO DISENGAGE FIRING MEMBER LOCKOUT FEATURES, now U.S. Pat. No. 10,687,809;U.S. patent application Ser. No. 15/385,923, entitled SURGICAL STAPLING SYSTEMS, now U.S. Patent Application Publication No. 2018/0168623;U.S. patent application Ser. No. 15/385,925, entitled JAW ACTUATED LOCK ARRANGEMENTS FOR PREVENTING ADVANCEMENT OF A FIRING MEMBER IN A SURGICAL END EFFECTOR UNLESS AN UNFIRED CARTRIDGE IS INSTALLED IN THE END EFFECTOR, now U.S. Pat. No. 10,517,595;U.S. patent application Ser. No. 15/385,926, entitled AXIALLY MOVABLE CLOSURE SYSTEM ARRANGEMENTS FOR APPLYING CLOSURE MOTIONS TO JAWS OF SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2018/0168577;U.S. patent application Ser. No. 15/385,928, entitled PROTECTIVE COVER ARRANGEMENTS FOR A JOINT INTERFACE BETWEEN A MOVABLE JAW AND ACTUATOR SHAFT OF A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2018/0168578;U.S. patent application Ser. No. 15/385,930, entitled SURGICAL END EFFECTOR WITH TWO SEPARATE COOPERATING OPENING FEATURES FOR OPENING AND CLOSING END EFFECTOR JAWS, now U.S. Patent Application Publication No. 2018/0168579;U.S. patent application Ser. No. 15/385,932, entitled ARTICULATABLE SURGICAL END EFFECTOR WITH ASYMMETRIC SHAFT ARRANGEMENT, now U.S. Patent Application Publication No. 2018/0168628;U.S. patent application Ser. No. 15/385,933, entitled ARTICULATABLE SURGICAL INSTRUMENT WITH INDEPENDENT PIVOTABLE LINKAGE DISTAL OF AN ARTICULATION LOCK, now U.S. Pat. No. 10,603,036;U.S. patent application Ser. No. 15/385,934, entitled ARTICULATION LOCK ARRANGEMENTS FOR LOCKING AN END EFFECTOR IN AN ARTICULATED POSITION IN RESPONSE TO ACTUATION OF A JAW CLOSURE SYSTEM, now U.S. Pat. No. 10,582,928;U.S. patent application Ser. No. 15/385,935, entitled LATERALLY ACTUATABLE ARTICULATION LOCK ARRANGEMENTS FOR LOCKING AN END EFFECTOR OF A SURGICAL INSTRUMENT IN AN ARTICULATED CONFIGURATION, now U.S. Pat. No. 10,524,789;U.S. patent application Ser. No. 15/385,936, entitled ARTICULATABLE SURGICAL INSTRUMENTS WITH ARTICULATION STROKE AMPLIFICATION FEATURES, now U.S. Pat. No. 10,517,596;U.S. patent application Ser. No. 14/318,996, entitled FASTENER CARTRIDGES INCLUDING EXTENSIONS HAVING DIFFERENT CONFIGURATIONS, now U.S. Patent Application Publication No. 2015/0297228;U.S. patent application Ser. No. 14/319,006, entitled FASTENER CARTRIDGE COMPRISING FASTENER CAVITIES INCLUDING FASTENER CONTROL FEATURES, now U.S. Pat. No. 10,010,324;U.S. patent application Ser. No. 14/318,991, entitled SURGICAL FASTENER CARTRIDGES WITH DRIVER STABILIZING ARRANGEMENTS, now U.S. Pat. No. 9,833,241;U.S. patent application Ser. No. 14/319,004, entitled SURGICAL END EFFECTORS WITH FIRING ELEMENT MONITORING ARRANGEMENTS, now U.S. Pat. No. 9,844,369;U.S. patent application Ser. No. 14/319,008, entitled FASTENER CARTRIDGE COMPRISING NON-UNIFORM FASTENERS, now U.S. Pat. No. 10,299,792;U.S. patent application Ser. No. 14/318,997, entitled FASTENER CARTRIDGE COMPRISING DEPLOYABLE TISSUE ENGAGING MEMBERS, now U.S. Pat. No. 10,561,422;U.S. patent application Ser. No. 14/319,002, entitled FASTENER CARTRIDGE COMPRISING TISSUE CONTROL FEATURES, now U.S. Pat. No. 9,877,721;U.S. patent application Ser. No. 14/319,013, entitled FASTENER CARTRIDGE ASSEMBLIES AND STAPLE RETAINER COVER ARRANGEMENTS, now U.S. Patent Application Publication No. 2015/0297233; andU.S. patent application Ser. No. 14/319,016, entitled FASTENER CARTRIDGE INCLUDING A LAYER ATTACHED THERETO, now U.S. Pat. No. 10,470,768. Applicant of the present application owns the following U.S. Patent Applications that were filed on Jun. 24, 2016 and which are each herein incorporated by reference in their respective entireties:U.S. patent application Ser. No. 15/191,775, entitled STAPLE CARTRIDGE COMPRISING WIRE STAPLES AND STAMPED STAPLES, now U.S. Patent Application Publication No. 2017/0367695;U.S. patent application Ser. No. 15/191,807, entitled STAPLING SYSTEM FOR USE WITH WIRE STAPLES AND STAMPED STAPLES, now U.S. Pat. No. 10,702,270;U.S. patent application Ser. No. 15/191,834, entitled STAMPED STAPLES AND STAPLE CARTRIDGES USING THE SAME, now U.S. Pat. No. 10,542,979;U.S. patent application Ser. No. 15/191,788, entitled STAPLE CARTRIDGE COMPRISING OVERDRIVEN STAPLES, now U.S. Pat. No. 10,675,024; andU.S. patent application Ser. No. 15/191,818, entitled STAPLE CARTRIDGE COMPRISING OFFSET LONGITUDINAL STAPLE ROWS, now U.S. Pat. No. 10,893,863. Applicant of the present application owns the following U.S. Patent Applications that were filed on Jun. 24, 2016 and which are each herein incorporated by reference in their respective entireties:U.S. Design patent application Ser. No. 29/569,218, entitled SURGICAL FASTENER, now U.S. Design Pat. No. D826,405;U.S. Design patent application Ser. No. 29/569,227, entitled SURGICAL FASTENER, now U.S. Design Pat. No. D822,206;U.S. Design patent application Ser. No. 29/569,259, entitled SURGICAL FASTENER CARTRIDGE, now U.S. Design Pat. No. D847,989; andU.S. Design patent application Ser. No. 29/569,264, entitled SURGICAL FASTENER CARTRIDGE, now U.S. Design Pat. No. D850,617. Applicant of the present application owns the following patent applications that were filed on Apr. 1, 2016 and which are each herein incorporated by reference in their respective entirety:U.S. patent application Ser. No. 15/089,325, entitled METHOD FOR OPERATING A SURGICAL STAPLING SYSTEM, now U.S. Patent Application Publication No. 2017/0281171;U.S. patent application Ser. No. 15/089,321, entitled MODULAR SURGICAL STAPLING SYSTEM COMPRISING A DISPLAY, now U.S. Pat. No. 10,271,851;U.S. patent application Ser. No. 15/089,326, entitled SURGICAL STAPLING SYSTEM COMPRISING A DISPLAY INCLUDING A RE-ORIENTABLE DISPLAY FIELD, now U.S. Pat. No. 10,433,849;U.S. patent application Ser. No. 15/089,263, entitled SURGICAL INSTRUMENT HANDLE ASSEMBLY WITH RECONFIGURABLE GRIP PORTION, now U.S. Pat. No. 10,307,159;U.S. patent application Ser. No. 15/089,262, entitled ROTARY POWERED SURGICAL INSTRUMENT WITH MANUALLY ACTUATABLE BAILOUT SYSTEM, now U.S. Pat. No. 10,357,246;U.S. patent application Ser. No. 15/089,277, entitled SURGICAL CUTTING AND STAPLING END EFFECTOR WITH ANVIL CONCENTRIC DRIVE MEMBER, now U.S. Pat. No. 10,531,874;U.S. patent application Ser. No. 15/089,296, entitled INTERCHANGEABLE SURGICAL TOOL ASSEMBLY WITH A SURGICAL END EFFECTOR THAT IS SELECTIVELY ROTATABLE ABOUT A SHAFT AXIS, now U.S. Pat. No. 10,413,293;U.S. patent application Ser. No. 15/089,258, entitled SURGICAL STAPLING SYSTEM COMPRISING A SHIFTABLE TRANSMISSION, now U.S. Pat. No. 10,342,543;U.S. patent application Ser. No. 15/089,278, entitled SURGICAL STAPLING SYSTEM CONFIGURED TO PROVIDE SELECTIVE CUTTING OF TISSUE, now U.S. Pat. No. 10,420,552;U.S. patent application Ser. No. 15/089,284, entitled SURGICAL STAPLING SYSTEM COMPRISING A CONTOURABLE SHAFT, now U.S. Patent Application Publication No. 2017/0281186;U.S. patent application Ser. No. 15/089,295, entitled SURGICAL STAPLING SYSTEM COMPRISING A TISSUE COMPRESSION LOCKOUT, now U.S. Pat. No. 10,856,867;U.S. patent application Ser. No. 15/089,300, entitled SURGICAL STAPLING SYSTEM COMPRISING AN UNCLAMPING LOCKOUT, now U.S. Pat. No. 10,456,140;U.S. patent application Ser. No. 15/089,196, entitled SURGICAL STAPLING SYSTEM COMPRISING A JAW CLOSURE LOCKOUT, now U.S. Pat. No. 10,568,632;U.S. patent application Ser. No. 15/089,203, entitled SURGICAL STAPLING SYSTEM COMPRISING A JAW ATTACHMENT LOCKOUT, now U.S. Pat. No. 10,542,991;U.S. patent application Ser. No. 15/089,210, entitled SURGICAL STAPLING SYSTEM COMPRISING A SPENT CARTRIDGE LOCKOUT, now U.S. Pat. No. 10,478,190;U.S. patent application Ser. No. 15/089,324, entitled SURGICAL INSTRUMENT COMPRISING A SHIFTING MECHANISM, now U.S. Pat. No. 10,314,582;U.S. patent application Ser. No. 15/089,335, entitled SURGICAL STAPLING INSTRUMENT COMPRISING MULTIPLE LOCKOUTS, now U.S. Pat. No. 10,485,542;U.S. patent application Ser. No. 15/089,339, entitled SURGICAL STAPLING INSTRUMENT, now U.S. Patent Application Publication No. 2017/0281173;U.S. patent application Ser. No. 15/089,253, entitled SURGICAL STAPLING SYSTEM CONFIGURED TO APPLY ANNULAR ROWS OF STAPLES HAVING DIFFERENT HEIGHTS, now U.S. Pat. No. 10,413,297;U.S. patent application Ser. No. 15/089,304, entitled SURGICAL STAPLING SYSTEM COMPRISING A GROOVED FORMING POCKET, now U.S. Pat. No. 10,285,705;U.S. patent application Ser. No. 15/089,331, entitled ANVIL MODIFICATION MEMBERS FOR SURGICAL STAPLERS, now U.S. Pat. No. 10,376,263;U.S. patent application Ser. No. 15/089,336, entitled STAPLE CARTRIDGES WITH ATRAUMATIC FEATURES, now U.S. Pat. No. 10,709,446;U.S. patent application Ser. No. 15/089,312, entitled CIRCULAR STAPLING SYSTEM COMPRISING AN INCISABLE TISSUE SUPPORT, now U.S. Patent Application Publication No. 2017/0281189;U.S. patent application Ser. No. 15/089,309, entitled CIRCULAR STAPLING SYSTEM COMPRISING ROTARY FIRING SYSTEM, now U.S. Pat. No. 10,675,021; andU.S. patent application Ser. No. 15/089,349, entitled CIRCULAR STAPLING SYSTEM COMPRISING LOAD CONTROL, now U.S. Pat. No. 10,682,136. Applicant of the present application also owns the U.S. Patent Applications identified below which were filed on Dec. 30, 2015 which are each herein incorporated by reference in their respective entirety:U.S. patent application Ser. No. 14/984,488, entitled MECHANISMS FOR COMPENSATING FOR BATTERY PACK FAILURE IN POWERED SURGICAL INSTRUMENTS, now U.S. Pat. No. 10,292,704;U.S. patent application Ser. No. 14/984,525, entitled MECHANISMS FOR COMPENSATING FOR DRIVETRAIN FAILURE IN POWERED SURGICAL INSTRUMENTS, now U.S. Pat. No. 10,368,865; andU.S. patent application Ser. No. 14/984,552, entitled SURGICAL INSTRUMENTS WITH SEPARABLE MOTORS AND MOTOR CONTROL CIRCUITS, now U.S. Pat. No. 10,265,068. Applicant of the present application also owns the U.S. Patent Applications identified below which were filed on Feb. 9, 2016, which are each herein incorporated by reference in their respective entirety:U.S. patent application Ser. No. 15/019,220, entitled SURGICAL INSTRUMENT WITH ARTICULATING AND AXIALLY TRANSLATABLE END EFFECTOR, now U.S. Pat. No. 10,245,029;U.S. patent application Ser. No. 15/019,228, entitled SURGICAL INSTRUMENTS WITH MULTIPLE LINK ARTICULATION ARRANGEMENTS, now U.S. Pat. No. 10,433,837;U.S. patent application Ser. No. 15/019,196, entitled SURGICAL INSTRUMENT ARTICULATION MECHANISM WITH SLOTTED SECONDARY CONSTRAINT, now U.S. Pat. No. 10,413,291;U.S. patent application Ser. No. 15/019,206, entitled SURGICAL INSTRUMENTS WITH AN END EFFECTOR THAT IS HIGHLY ARTICULATABLE RELATIVE TO AN ELONGATE SHAFT ASSEMBLY, now U.S. Pat. No. 10,653,413;U.S. patent application Ser. No. 15/019,215, entitled SURGICAL INSTRUMENTS WITH NON-SYMMETRICAL ARTICULATION ARRANGEMENTS, now U.S. Patent Application Publication No. 2017/0224332;U.S. patent application Ser. No. 15/019,227, entitled ARTICULATABLE SURGICAL INSTRUMENTS WITH SINGLE ARTICULATION LINK ARRANGEMENTS, now U.S. Patent Application Publication No. 2017/0224334;U.S. patent application Ser. No. 15/019,235, entitled SURGICAL INSTRUMENTS WITH TENSIONING ARRANGEMENTS FOR CABLE DRIVEN ARTICULATION SYSTEMS, now U.S. Pat. No. 10,245,030;U.S. patent application Ser. No. 15/019,230, entitled ARTICULATABLE SURGICAL INSTRUMENTS WITH OFF-AXIS FIRING BEAM ARRANGEMENTS, now U.S. Pat. No. 10,588,625; andU.S. patent application Ser. No. 15/019,245, entitled SURGICAL INSTRUMENTS WITH CLOSURE STROKE REDUCTION ARRANGEMENTS, now U.S. Pat. No. 10,470,764. Applicant of the present application also owns the U.S. Patent Applications identified below which were filed on Feb. 12, 2016, which are each herein incorporated by reference in their respective entirety:U.S. patent application Ser. No. 15/043,254, entitled MECHANISMS FOR COMPENSATING FOR DRIVETRAIN FAILURE IN POWERED SURGICAL INSTRUMENTS, now U.S. Pat. No. 10,258,331;U.S. patent application Ser. No. 15/043,259, entitled MECHANISMS FOR COMPENSATING FOR DRIVETRAIN FAILURE IN POWERED SURGICAL INSTRUMENTS, now U.S. Pat. No. 10,448,948;U.S. patent application Ser. No. 15/043,275, entitled MECHANISMS FOR COMPENSATING FOR DRIVETRAIN FAILURE IN POWERED SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2017/0231627; andU.S. patent application Ser. No. 15/043,289, entitled MECHANISMS FOR COMPENSATING FOR DRIVETRAIN FAILURE IN POWERED SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2017/0231628. Applicant of the present application owns the following patent applications that were filed on Jun. 18, 2015 and which are each herein incorporated by reference in their respective entirety:U.S. patent application Ser. No. 14/742,925, entitled SURGICAL END EFFECTORS WITH POSITIVE JAW OPENING ARRANGEMENTS, now U.S. Pat. No. 10,182,818;U.S. patent application Ser. No. 14/742,941, entitled SURGICAL END EFFECTORS WITH DUAL CAM ACTUATED JAW CLOSING FEATURES, now U.S. Pat. No. 10,052,102;U.S. patent application Ser. No. 14/742,933, entitled SURGICAL STAPLING INSTRUMENTS WITH LOCKOUT ARRANGEMENTS FOR PREVENTING FIRING SYSTEM ACTUATION WHEN A CARTRIDGE IS SPENT OR MISSING, now U.S. Pat. No. 10,154,841;U.S. patent application Ser. No. 14/742,914, entitled MOVABLE FIRING BEAM SUPPORT ARRANGEMENTS FOR ARTICULATABLE SURGICAL INSTRUMENTS, now U.S. Pat. No. 10,405,863;U.S. patent application Ser. No. 14/742,900, entitled ARTICULATABLE SURGICAL INSTRUMENTS WITH COMPOSITE FIRING BEAM STRUCTURES WITH CENTER FIRING SUPPORT MEMBER FOR ARTICULATION SUPPORT, now U.S. Pat. No. 10,335,149;U.S. patent application Ser. No. 14/742,885, entitled DUAL ARTICULATION DRIVE SYSTEM ARRANGEMENTS FOR ARTICULATABLE SURGICAL INSTRUMENTS, now U.S. Pat. No. 10,368,861; andU.S. patent application Ser. No. 14/742,876, entitled PUSH/PULL ARTICULATION DRIVE SYSTEMS FOR ARTICULATABLE SURGICAL INSTRUMENTS, now U.S. Pat. No. 10,178,992.Applicant of the present application owns the following patent applications that were filed on Mar. 6, 2015 and which are each herein incorporated by reference in their respective entirety:U.S. patent application Ser. No. 14/640,746, entitled POWERED SURGICAL INSTRUMENT, now U.S. Pat. No. 9,808,246;U.S. patent application Ser. No. 14/640,795, entitled MULTIPLE LEVEL THRESHOLDS TO MODIFY OPERATION OF POWERED SURGICAL INSTRUMENTS, now U.S. Pat. No. 10,441,279;U.S. patent application Ser. No. 14/640,832, entitled ADAPTIVE TISSUE COMPRESSION TECHNIQUES TO ADJUST CLOSURE RATES FOR MULTIPLE TISSUE TYPES, now U.S. Pat. No. 10,687,806;U.S. patent application Ser. No. 14/640,935, entitled OVERLAID MULTI SENSOR RADIO FREQUENCY (RF) ELECTRODE SYSTEM TO MEASURE TISSUE COMPRESSION, now U.S. Pat. No. 10,548,504;U.S. patent application Ser. No. 14/640,831, entitled MONITORING SPEED CONTROL AND PRECISION INCREMENTING OF MOTOR FOR POWERED SURGICAL INSTRUMENTS, now U.S. Pat. No. 9,895,148;U.S. patent application Ser. No. 14/640,859, entitled TIME DEPENDENT EVALUATION OF SENSOR DATA TO DETERMINE STABILITY, CREEP, AND VISCOELASTIC ELEMENTS OF MEASURES, now U.S. Pat. No. 10,052,044;U.S. patent application Ser. No. 14/640,817, entitled INTERACTIVE FEEDBACK SYSTEM FOR POWERED SURGICAL INSTRUMENTS, now U.S. Pat. No. 9,924,961;U.S. patent application Ser. No. 14/640,844, entitled CONTROL TECHNIQUES AND SUB-PROCESSOR CONTAINED WITHIN MODULAR SHAFT WITH SELECT CONTROL PROCESSING FROM HANDLE, now U.S. Pat. No. 10,045,776;U.S. patent application Ser. No. 14/640,837, entitled SMART SENSORS WITH LOCAL SIGNAL PROCESSING, now U.S. Pat. No. 9,993,248;U.S. patent application Ser. No. 14/640,765, entitled SYSTEM FOR DETECTING THE MIS-INSERTION OF A STAPLE CARTRIDGE INTO A SURGICAL STAPLER, now U.S. Pat. No. 10,617,412;U.S. patent application Ser. No. 14/640,799, entitled SIGNAL AND POWER COMMUNICATION SYSTEM POSITIONED ON A ROTATABLE SHAFT, now U.S. Pat. No. 9,901,342; andU.S. patent application Ser. No. 14/640,780, entitled SURGICAL INSTRUMENT COMPRISING A LOCKABLE BATTERY HOUSING, now U.S. Pat. No. 10,245,033. Applicant of the present application owns the following patent applications that were filed on Feb. 27, 2015, and which are each herein incorporated by reference in their respective entirety:U.S. patent application Ser. No. 14/633,576, entitled SURGICAL INSTRUMENT SYSTEM COMPRISING AN INSPECTION STATION, now U.S. Pat. No. 10,045,779;U.S. patent application Ser. No. 14/633,546, entitled SURGICAL APPARATUS CONFIGURED TO ASSESS WHETHER A PERFORMANCE PARAMETER OF THE SURGICAL APPARATUS IS WITHIN AN ACCEPTABLE PERFORMANCE BAND, now U.S. Pat. No. 10,180,463;U.S. patent application Ser. No. 14/633,560, entitled SURGICAL CHARGING SYSTEM THAT CHARGES AND/OR CONDITIONS ONE OR MORE BATTERIES, now U.S. Patent Application Publication No. 2016/0249910;U.S. patent application Ser. No. 14/633,566, entitled CHARGING SYSTEM THAT ENABLES EMERGENCY RESOLUTIONS FOR CHARGING A BATTERY, now U.S. Pat. No. 10,182,816;U.S. patent application Ser. No. 14/633,555, entitled SYSTEM FOR MONITORING WHETHER A SURGICAL INSTRUMENT NEEDS TO BE SERVICED, now U.S. Pat. No. 10,321,907;U.S. patent application Ser. No. 14/633,542, entitled REINFORCED BATTERY FOR A SURGICAL INSTRUMENT, now U.S. Pat. No. 9,931,118;U.S. patent application Ser. No. 14/633,548, entitled POWER ADAPTER FOR A SURGICAL INSTRUMENT, now U.S. Pat. No. 10,245,028;U.S. patent application Ser. No. 14/633,526, entitled ADAPTABLE SURGICAL INSTRUMENT HANDLE, now U.S. Pat. No. 9,993,258;U.S. patent application Ser. No. 14/633,541, entitled MODULAR STAPLING ASSEMBLY, now U.S. Pat. No. 10,226,250; andU.S. patent application Ser. No. 14/633,562, entitled SURGICAL APPARATUS CONFIGURED TO TRACK AN END-OF-LIFE PARAMETER, now U.S. Pat. No. 10,159,483. Applicant of the present application owns the following patent applications that were filed on Dec. 18, 2014 and which are each herein incorporated by reference in their respective entirety:U.S. patent application Ser. No. 14/574,478, entitled SURGICAL INSTRUMENT SYSTEMS COMPRISING AN ARTICULATABLE END EFFECTOR AND MEANS FOR ADJUSTING THE FIRING STROKE OF A FIRING MEMBER, now U.S. Pat. No. 9,844,374;U.S. patent application Ser. No. 14/574,483, entitled SURGICAL INSTRUMENT ASSEMBLY COMPRISING LOCKABLE SYSTEMS, now U.S. Pat. No. 10,188,385;U.S. patent application Ser. No. 14/575,139, entitled DRIVE ARRANGEMENTS FOR ARTICULATABLE SURGICAL INSTRUMENTS, now U.S. Pat. No. 9,844,375;U.S. patent application Ser. No. 14/575,148, entitled LOCKING ARRANGEMENTS FOR DETACHABLE SHAFT ASSEMBLIES WITH ARTICULATABLE SURGICAL END EFFECTORS, now U.S. Pat. No. 10,085,748;U.S. patent application Ser. No. 14/575,130, entitled SURGICAL INSTRUMENT WITH AN ANVIL THAT IS SELECTIVELY MOVABLE ABOUT A DISCRETE NON-MOVABLE AXIS RELATIVE TO A STAPLE CARTRIDGE, now U.S. Pat. No. 10,245,027;U.S. patent application Ser. No. 14/575,143, entitled SURGICAL INSTRUMENTS WITH IMPROVED CLOSURE ARRANGEMENTS, now U.S. Pat. No. 10,004,501;U.S. patent application Ser. No. 14/575,117, entitled SURGICAL INSTRUMENTS WITH ARTICULATABLE END EFFECTORS AND MOVABLE FIRING BEAM SUPPORT ARRANGEMENTS, now U.S. Pat. No. 9,943,309;U.S. patent application Ser. No. 14/575,154, entitled SURGICAL INSTRUMENTS WITH ARTICULATABLE END EFFECTORS AND IMPROVED FIRING BEAM SUPPORT ARRANGEMENTS, now U.S. Pat. No. 9,968,355;U.S. patent application Ser. No. 14/574,493, entitled SURGICAL INSTRUMENT ASSEMBLY COMPRISING A FLEXIBLE ARTICULATION SYSTEM, now U.S. Pat. No. 9,987,000; andU.S. patent application Ser. No. 14/574,500, entitled SURGICAL INSTRUMENT ASSEMBLY COMPRISING A LOCKABLE ARTICULATION SYSTEM, now U.S. Pat. No. 10,117,649. Applicant of the present application owns the following patent applications that were filed on Mar. 1, 2013 and which are each herein incorporated by reference in their respective entirety:U.S. patent application Ser. No. 13/782,295, entitled ARTICULATABLE SURGICAL INSTRUMENTS WITH CONDUCTIVE PATHWAYS FOR SIGNAL COMMUNICATION, now U.S. Pat. No. 9,700,309;U.S. patent application Ser. No. 13/782,323, entitled ROTARY POWERED ARTICULATION JOINTS FOR SURGICAL INSTRUMENTS, now U.S. Pat. No. 9,782,169;U.S. patent application Ser. No. 13/782,338, entitled THUMBWHEEL SWITCH ARRANGEMENTS FOR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2014/0249557;U.S. patent application Ser. No. 13/782,499, entitled ELECTROMECHANICAL SURGICAL DEVICE WITH SIGNAL RELAY ARRANGEMENT, now U.S. Pat. No. 9,358,003;U.S. patent application Ser. No. 13/782,460, entitled MULTIPLE PROCESSOR MOTOR CONTROL FOR MODULAR SURGICAL INSTRUMENTS, now U.S. Pat. No. 9,554,794;U.S. patent application Ser. No. 13/782,358, entitled JOYSTICK SWITCH ASSEMBLIES FOR SURGICAL INSTRUMENTS, now U.S. Pat. No. 9,326,767;U.S. patent application Ser. No. 13/782,481, entitled SENSOR STRAIGHTENED END EFFECTOR DURING REMOVAL THROUGH TROCAR, now U.S. Pat. No. 9,468,438;U.S. patent application Ser. No. 13/782,518, entitled CONTROL METHODS FOR SURGICAL INSTRUMENTS WITH REMOVABLE IMPLEMENT PORTIONS, now U.S. Patent Application Publication No. 2014/0246475;U.S. patent application Ser. No. 13/782,375, entitled ROTARY POWERED SURGICAL INSTRUMENTS WITH MULTIPLE DEGREES OF FREEDOM, now U.S. Pat. No. 9,398,911; andU.S. patent application Ser. No. 13/782,536, entitled SURGICAL INSTRUMENT SOFT STOP, now U.S. Pat. No. 9,307,986. Applicant of the present application also owns the following patent applications that were filed on Mar. 14, 2013 and which are each herein incorporated by reference in their respective entirety:U.S. patent application Ser. No. 13/803,097, entitled ARTICULATABLE SURGICAL INSTRUMENT COMPRISING A FIRING DRIVE, now U.S. Pat. No. 9,687,230;U.S. patent application Ser. No. 13/803,193, entitled CONTROL ARRANGEMENTS FOR A DRIVE MEMBER OF A SURGICAL INSTRUMENT, now U.S. Pat. No. 9,332,987;U.S. patent application Ser. No. 13/803,053, entitled INTERCHANGEABLE SHAFT ASSEMBLIES FOR USE WITH A SURGICAL INSTRUMENT, now U.S. Pat. No. 9,883,860;U.S. patent application Ser. No. 13/803,086, entitled ARTICULATABLE SURGICAL INSTRUMENT COMPRISING AN ARTICULATION LOCK, now U.S. Patent Application Publication No. 2014/0263541;U.S. patent application Ser. No. 13/803,210, entitled SENSOR ARRANGEMENTS FOR ABSOLUTE POSITIONING SYSTEM FOR SURGICAL INSTRUMENTS, now U.S. Pat. No. 9,808,244;U.S. patent application Ser. No. 13/803,148, entitled MULTI-FUNCTION MOTOR FOR A SURGICAL INSTRUMENT, now U.S. Pat. No. 10,470,762;U.S. patent application Ser. No. 13/803,066, entitled DRIVE SYSTEM LOCKOUT ARRANGEMENTS FOR MODULAR SURGICAL INSTRUMENTS, now U.S. Pat. No. 9,629,623;U.S. patent application Ser. No. 13/803,117, entitled ARTICULATION CONTROL SYSTEM FOR ARTICULATABLE SURGICAL INSTRUMENTS, now U.S. Pat. No. 9,351,726;U.S. patent application Ser. No. 13/803,130, entitled DRIVE TRAIN CONTROL ARRANGEMENTS FOR MODULAR SURGICAL INSTRUMENTS, now U.S. Pat. No. 9,351,727; andU.S. patent application Ser. No. 13/803,159, entitled METHOD AND SYSTEM FOR OPERATING A SURGICAL INSTRUMENT, now U.S. Pat. No. 9,888,919. Applicant of the present application also owns the following patent application that was filed on Mar. 7, 2014 and is herein incorporated by reference in its entirety:U.S. patent application Ser. No. 14/200,111, entitled CONTROL SYSTEMS FOR SURGICAL INSTRUMENTS, now U.S. Pat. No. 9,629,629. Applicant of the present application also owns the following patent applications that were filed on Mar. 26, 2014 and are each herein incorporated by reference in their respective entirety:U.S. patent application Ser. No. 14/226,106, entitled POWER MANAGEMENT CONTROL SYSTEMS FOR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2015/0272582;U.S. patent application Ser. No. 14/226,099, entitled STERILIZATION VERIFICATION CIRCUIT, now U.S. Pat. No. 9,826,977;U.S. patent application Ser. No. 14/226,094, entitled VERIFICATION OF NUMBER OF BATTERY EXCHANGES/PROCEDURE COUNT, now U.S. Patent Application Publication No. 2015/0272580;U.S. patent application Ser. No. 14/226,117, entitled POWER MANAGEMENT THROUGH SLEEP OPTIONS OF SEGMENTED CIRCUIT AND WAKE UP CONTROL, now U.S. Pat. No. 10,013,049;U.S. patent application Ser. No. 14/226,075, entitled MODULAR POWERED SURGICAL INSTRUMENT WITH DETACHABLE SHAFT ASSEMBLIES, now U.S. Pat. No. 9,743,929;U.S. patent application Ser. No. 14/226,093, entitled FEEDBACK ALGORITHMS FOR MANUAL BAILOUT SYSTEMS FOR SURGICAL INSTRUMENTS, now U.S. Pat. No. 10,028,761;U.S. patent application Ser. No. 14/226,116, entitled SURGICAL INSTRUMENT UTILIZING SENSOR ADAPTATION, now U.S. Patent Application Publication No. 2015/0272571;U.S. patent application Ser. No. 14/226,071, entitled SURGICAL INSTRUMENT CONTROL CIRCUIT HAVING A SAFETY PROCESSOR, now U.S. Pat. No. 9,690,362;U.S. patent application Ser. No. 14/226,097, entitled SURGICAL INSTRUMENT COMPRISING INTERACTIVE SYSTEMS, now U.S. Pat. No. 9,820,738;U.S. patent application Ser. No. 14/226,126, entitled INTERFACE SYSTEMS FOR USE WITH SURGICAL INSTRUMENTS, now U.S. Pat. No. 10,004,497;U.S. patent application Ser. No. 14/226,133, entitled MODULAR SURGICAL INSTRUMENT SYSTEM, now U.S. Patent Application Publication No. 2015/0272557;U.S. patent application Ser. No. 14/226,081, entitled SYSTEMS AND METHODS FOR CONTROLLING A SEGMENTED CIRCUIT, now U.S. Pat. No. 9,804,618;U.S. patent application Ser. No. 14/226,076, entitled POWER MANAGEMENT THROUGH SEGMENTED CIRCUIT AND VARIABLE VOLTAGE PROTECTION, now U.S. Pat. No. 9,733,663;U.S. patent application Ser. No. 14/226,111, entitled SURGICAL STAPLING INSTRUMENT SYSTEM, now U.S. Pat. No. 9,750,499; andU.S. patent application Ser. No. 14/226,125, entitled SURGICAL INSTRUMENT COMPRISING A ROTATABLE SHAFT, now U.S. Pat. No. 10,201,364. Applicant of the present application also owns the following patent applications that were filed on Sep. 5, 2014 and which are each herein incorporated by reference in their respective entirety:U.S. patent application Ser. No. 14/479,103, entitled CIRCUITRY AND SENSORS FOR POWERED MEDICAL DEVICE, now U.S. Pat. No. 10,111,679;U.S. patent application Ser. No. 14/479,119, entitled ADJUNCT WITH INTEGRATED SENSORS TO QUANTIFY TISSUE COMPRESSION, now U.S. Pat. No. 9,724,094;U.S. patent application Ser. No. 14/478,908, entitled MONITORING DEVICE DEGRADATION BASED ON COMPONENT EVALUATION, now U.S. Pat. No. 9,737,301;U.S. patent application Ser. No. 14/478,895, entitled MULTIPLE SENSORS WITH ONE SENSOR AFFECTING A SECOND SENSOR'S OUTPUT OR INTERPRETATION, now U.S. Pat. No. 9,757,128;U.S. patent application Ser. No. 14/479,110, entitled POLARITY OF HALL MAGNET TO IDENTIFY CARTRIDGE TYPE, now U.S. Pat. No. 10,016,199;U.S. patent application Ser. No. 14/479,098, entitled SMART CARTRIDGE WAKE UP OPERATION AND DATA RETENTION, now U.S. Pat. No. 10,135,242;U.S. patent application Ser. No. 14/479,115, entitled MULTIPLE MOTOR CONTROL FOR POWERED MEDICAL DEVICE, now U.S. Pat. No. 9,788,836; andU.S. patent application Ser. No. 14/479,108, entitled LOCAL DISPLAY OF TISSUE PARAMETER STABILIZATION, now U.S. Patent Application Publication No. 2016/0066913. Applicant of the present application also owns the following patent applications that were filed on Apr. 9, 2014 and which are each herein incorporated by reference in their respective entirety:U.S. patent application Ser. No. 14/248,590, entitled MOTOR DRIVEN SURGICAL INSTRUMENTS WITH LOCKABLE DUAL DRIVE SHAFTS, now U.S. Pat. No. 9,826,976;U.S. patent application Ser. No. 14/248,581, entitled SURGICAL INSTRUMENT COMPRISING A CLOSING DRIVE AND A FIRING DRIVE OPERATED FROM THE SAME ROTATABLE OUTPUT, now U.S. Pat. No. 9,649,110;U.S. patent application Ser. No. 14/248,595, entitled SURGICAL SYSTEM COMPRISING FIRST AND SECOND DRIVE SYSTEMS, now U.S. Pat. No. 9,844,368;U.S. patent application Ser. No. 14/248,588, entitled POWERED LINEAR SURGICAL STAPLER, now U.S. Pat. No. 10,405,857;U.S. patent application Ser. No. 14/248,591, entitled SURGICAL INSTRUMENT COMPRISING A GAP SETTING SYSTEM, now U.S. Pat. No. 10,149,680;U.S. patent application Ser. No. 14/248,584, entitled MODULAR MOTOR DRIVEN SURGICAL INSTRUMENTS WITH ALIGNMENT FEATURES FOR ALIGNING ROTARY DRIVE SHAFTS WITH SURGICAL END EFFECTOR SHAFTS, now U.S. Pat. No. 9,801,626;U.S. patent application Ser. No. 14/248,587, entitled POWERED SURGICAL STAPLER, now U.S. Pat. No. 9,867,612;U.S. patent application Ser. No. 14/248,586, entitled DRIVE SYSTEM DECOUPLING ARRANGEMENT FOR A SURGICAL INSTRUMENT, now U.S. Pat. No. 10,136,887; andU.S. patent application Ser. No. 14/248,607, entitled MODULAR MOTOR DRIVEN SURGICAL INSTRUMENTS WITH STATUS INDICATION ARRANGEMENTS, now U.S. Pat. No. 9,814,460. Applicant of the present application also owns the following patent applications that were filed on Apr. 16, 2013 and which are each herein incorporated by reference in their respective entirety:U.S. Provisional Patent Application Ser. No. 61/812,365, entitled SURGICAL INSTRUMENT WITH MULTIPLE FUNCTIONS PERFORMED BY A SINGLE MOTOR;U.S. Provisional Patent Application Ser. No. 61/812,376, entitled LINEAR CUTTER WITH POWER;U.S. Provisional Patent Application Ser. No. 61/812,382, entitled LINEAR CUTTER WITH MOTOR AND PISTOL GRIP;U.S. Provisional Patent Application Ser. No. 61/812,385, entitled SURGICAL INSTRUMENT HANDLE WITH MULTIPLE ACTUATION MOTORS AND MOTOR CONTROL; andU.S. Provisional Patent Application Ser. No. 61/812,372, entitled SURGICAL INSTRUMENT WITH MULTIPLE FUNCTIONS PERFORMED BY A SINGLE MOTOR. Applicant of the present application owns the following U.S. Provisional Patent Applications, filed on Dec. 28, 2017, the disclosure of each of which is herein incorporated by reference in its entirety:U.S. Provisional Patent Application Ser. No. 62/611,341, entitled INTERACTIVE SURGICAL PLATFORM;U.S. Provisional Patent Application Ser. No. 62/611,340, entitled CLOUD-BASED MEDICAL ANALYTICS; andU.S. Provisional Patent Application Ser. No. 62/611,339, entitled ROBOT ASSISTED SURGICAL PLATFORM. Applicant of the present application owns the following U.S. Provisional Patent Applications, filed on Mar. 28, 2018, each of which is herein incorporated by reference in its entirety:U.S. Provisional Patent Application Ser. No. 62/649,302, entitled INTERACTIVE SURGICAL SYSTEMS WITH ENCRYPTED COMMUNICATION CAPABILITIES;U.S. Provisional Patent Application Ser. No. 62/649,294, entitled DATA STRIPPING METHOD TO INTERROGATE PATIENT RECORDS AND CREATE ANONYMIZED RECORD;U.S. Provisional Patent Application Ser. No. 62/649,300, entitled SURGICAL HUB SITUATIONAL AWARENESS;U.S. Provisional Patent Application Ser. No. 62/649,309, entitled SURGICAL HUB SPATIAL AWARENESS TO DETERMINE DEVICES IN OPERATING THEATER;U.S. Provisional Patent Application Ser. No. 62/649,310, entitled COMPUTER IMPLEMENTED INTERACTIVE SURGICAL SYSTEMS;U.S. Provisional Patent Application Ser. No. 62/649,291, entitled USE OF LASER LIGHT AND RED-GREEN-BLUE COLORATION TO DETERMINE PROPERTIES OF BACK SCATTERED LIGHT;U.S. Provisional Patent Application Ser. No. 62/649,296, entitled ADAPTIVE CONTROL PROGRAM UPDATES FOR SURGICAL DEVICES;U.S. Provisional Patent Application Ser. No. 62/649,333, entitled CLOUD-BASED MEDICAL ANALYTICS FOR CUSTOMIZATION AND RECOMMENDATIONS TO A USER;U.S. Provisional Patent Application Ser. No. 62/649,327, entitled CLOUD-BASED MEDICAL ANALYTICS FOR SECURITY AND AUTHENTICATION TRENDS AND REACTIVE MEASURES;U.S. Provisional Patent Application Ser. No. 62/649,315, entitled DATA HANDLING AND PRIORITIZATION IN A CLOUD ANALYTICS NETWORK;U.S. Provisional Patent Application Ser. No. 62/649,313, entitled CLOUD INTERFACE FOR COUPLED SURGICAL DEVICES;U.S. Provisional Patent Application Ser. No. 62/649,320, entitled DRIVE ARRANGEMENTS FOR ROBOT-ASSISTED SURGICAL PLATFORMS;U.S. Provisional Patent Application Ser. No. 62/649,307, entitled AUTOMATIC TOOL ADJUSTMENTS FOR ROBOT-ASSISTED SURGICAL PLATFORMS; andU.S. Provisional Patent Application Ser. No. 62/649,323, entitled SENSING ARRANGEMENTS FOR ROBOT-ASSISTED SURGICAL PLATFORMS. Applicant of the present application owns the following U.S. Patent Applications, filed on Mar. 29, 2018, each of which is herein incorporated by reference in its entirety:U.S. patent application Ser. No. 15/940,641, entitled INTERACTIVE SURGICAL SYSTEMS WITH ENCRYPTED COMMUNICATION CAPABILITIES, now U.S. Patent Application Publication No. 2019/0207911;U.S. patent application Ser. No. 15/940,648, entitled INTERACTIVE SURGICAL SYSTEMS WITH CONDITION HANDLING OF DEVICES AND DATA CAPABILITIES, now U.S. Patent Application Publication No. 2019/0206004;U.S. patent application Ser. No. 15/940,656, entitled SURGICAL HUB COORDINATION OF CONTROL AND COMMUNICATION OF OPERATING ROOM DEVICES, now U.S. Patent Application Publication No. 2019/0201141;U.S. patent application Ser. No. 15/940,666, entitled SPATIAL AWARENESS OF SURGICAL HUBS IN OPERATING ROOMS, now U.S. Patent Application Publication No. 2019/0206551;U.S. patent application Ser. No. 15/940,670, entitled COOPERATIVE UTILIZATION OF DATA DERIVED FROM SECONDARY SOURCES BY INTELLIGENT SURGICAL HUBS, now U.S. Patent Application Publication No. 2019/0201116;U.S. patent application Ser. No. 15/940,677, entitled SURGICAL HUB CONTROL ARRANGEMENTS, now U.S. Patent Application Publication No. 2019/0201143;U.S. patent application Ser. No. 15/940,632, entitled DATA STRIPPING METHOD TO INTERROGATE PATIENT RECORDS AND CREATE ANONYMIZED RECORD, now U.S. Patent Application Publication No. 2019/0205566;U.S. patent application Ser. No. 15/940,640, entitled COMMUNICATION HUB AND STORAGE DEVICE FOR STORING PARAMETERS AND STATUS OF A SURGICAL DEVICE TO BE SHARED WITH CLOUD BASED ANALYTICS SYSTEMS, now U.S. Patent Application Publication No. 2019/0200863;U.S. patent application Ser. No. 15/940,645, entitled SELF DESCRIBING DATA PACKETS GENERATED AT AN ISSUING INSTRUMENT, now U.S. Pat. No. 10,892,899;U.S. patent application Ser. No. 15/940,649, entitled DATA PAIRING TO INTERCONNECT A DEVICE MEASURED PARAMETER WITH AN OUTCOME, now U.S. Patent Application Publication No. 2019/0205567;U.S. patent application Ser. No. 15/940,654, entitled SURGICAL HUB SITUATIONAL AWARENESS, now U.S. Patent Application Publication No. 2019/0201140;U.S. patent application Ser. No. 15/940,663, entitled SURGICAL SYSTEM DISTRIBUTED PROCESSING, now U.S. Patent Application Publication No. 2019/0201033;U.S. patent application Ser. No. 15/940,668, entitled AGGREGATION AND REPORTING OF SURGICAL HUB DATA, now U.S. Patent Application Publication No. 2019/0201115;U.S. patent application Ser. No. 15/940,671, entitled SURGICAL HUB SPATIAL AWARENESS TO DETERMINE DEVICES IN OPERATING THEATER, now U.S. Patent Application Publication No. 2019/0201104;U.S. patent application Ser. No. 15/940,686, entitled DISPLAY OF ALIGNMENT OF STAPLE CARTRIDGE TO PRIOR LINEAR STAPLE LINE, now U.S. Patent Application Publication No. 2019/0201105;U.S. patent application Ser. No. 15/940,700, entitled STERILE FIELD INTERACTIVE CONTROL DISPLAYS, now U.S. Patent Application Publication No. 2019/0205001;U.S. patent application Ser. No. 15/940,629, entitled COMPUTER IMPLEMENTED INTERACTIVE SURGICAL SYSTEMS, now U.S. Patent Application Publication No. 2019/0201112;U.S. patent application Ser. No. 15/940,704, entitled USE OF LASER LIGHT AND RED-GREEN-BLUE COLORATION TO DETERMINE PROPERTIES OF BACK SCATTERED LIGHT, now U.S. Patent Application Publication No. 2019/0206050;U.S. patent application Ser. No. 15/940,722, entitled CHARACTERIZATION OF TISSUE IRREGULARITIES THROUGH THE USE OF MONO-CHROMATIC LIGHT REFRACTIVITY, now U.S. Patent Application Publication No. 2019/0200905; andU.S. patent application Ser. No. 15/940,742, entitled DUAL CMOS ARRAY IMAGING, now U.S. Patent Application Publication No. 2019/0200906. Applicant of the present application owns the following U.S. Patent Applications, filed on Mar. 29, 2018, each of which is herein incorporated by reference in its entirety:U.S. patent application Ser. No. 15/940,636, entitled ADAPTIVE CONTROL PROGRAM UPDATES FOR SURGICAL DEVICES, now U.S. Patent Application Publication No. 2019/0206003;U.S. patent application Ser. No. 15/940,653, entitled ADAPTIVE CONTROL PROGRAM UPDATES FOR SURGICAL HUBS, now U.S. Patent Application Publication No. 2019/0201114;U.S. patent application Ser. No. 15/940,660, entitled CLOUD-BASED MEDICAL ANALYTICS FOR CUSTOMIZATION AND RECOMMENDATIONS TO A USER, now U.S. Patent Application Publication No. 2019/0206555;U.S. patent application Ser. No. 15/940,679, entitled CLOUD-BASED MEDICAL ANALYTICS FOR LINKING OF LOCAL USAGE TRENDS WITH THE RESOURCE ACQUISITION BEHAVIORS OF LARGER DATA SET, now U.S. Patent Application Publication No. 2019/0201144;U.S. patent application Ser. No. 15/940,694, entitled CLOUD-BASED MEDICAL ANALYTICS FOR MEDICAL FACILITY SEGMENTED INDIVIDUALIZATION OF INSTRUMENT FUNCTION, now U.S. Patent Application Publication No. 2019/0201119;U.S. patent application Ser. No. 15/940,634, entitled CLOUD-BASED MEDICAL ANALYTICS FOR SECURITY AND AUTHENTICATION TRENDS AND REACTIVE MEASURES, now U.S. Patent Application Publication No. 2019/0201138;U.S. patent application Ser. No. 15/940,706, entitled DATA HANDLING AND PRIORITIZATION IN A CLOUD ANALYTICS NETWORK, now U.S. Patent Application Publication No. 2019/0206561; andU.S. patent application Ser. No. 15/940,675, entitled CLOUD INTERFACE FOR COUPLED SURGICAL DEVICES, now U.S. Pat. No. 10,849,697. Applicant of the present application owns the following U.S. Patent Applications, filed on Mar. 29, 2018, each of which is herein incorporated by reference in its entirety:U.S. patent application Ser. No. 15/940,627, entitled DRIVE ARRANGEMENTS FOR ROBOT-ASSISTED SURGICAL PLATFORMS, now U.S. Patent Application Publication No. 2019/0201111;U.S. patent application Ser. No. 15/940,637, entitled COMMUNICATION ARRANGEMENTS FOR ROBOT-ASSISTED SURGICAL PLATFORMS, now U.S. Patent Application Publication No. 2019/0201139;U.S. patent application Ser. No. 15/940,642, entitled CONTROLS FOR ROBOT-ASSISTED SURGICAL PLATFORMS, now U.S. Patent Application Publication No. 2019/0201113;U.S. patent application Ser. No. 15/940,676, entitled AUTOMATIC TOOL ADJUSTMENTS FOR ROBOT-ASSISTED SURGICAL PLATFORMS, now U.S. Patent Application Publication No. 2019/0201142;U.S. patent application Ser. No. 15/940,680, entitled CONTROLLERS FOR ROBOT-ASSISTED SURGICAL PLATFORMS, now U.S. Patent Application Publication No. 2019/0201135;U.S. patent application Ser. No. 15/940,683, entitled COOPERATIVE SURGICAL ACTIONS FOR ROBOT-ASSISTED SURGICAL PLATFORMS, now U.S. Patent Application Publication No. 2019/0201145;U.S. patent application Ser. No. 15/940,690, entitled DISPLAY ARRANGEMENTS FOR ROBOT-ASSISTED SURGICAL PLATFORMS, now U.S. Patent Application Publication No. 2019/0201118; andU.S. patent application Ser. No. 15/940,711, entitled SENSING ARRANGEMENTS FOR ROBOT-ASSISTED SURGICAL PLATFORMS, now U.S. Patent Application Publication No. 2019/0201120. Numerous specific details are set forth to provide a thorough understanding of the overall structure, function, manufacture, and use of the embodiments as described in the specification and illustrated in the accompanying drawings. Well-known operations, components, and elements have not been described in detail so as not to obscure the embodiments described in the specification. The reader will understand that the embodiments described and illustrated herein are non-limiting examples, and thus it can be appreciated that the specific structural and functional details disclosed herein may be representative and illustrative. Variations and changes thereto may be made without departing from the scope of the claims. The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a surgical system, device, or apparatus that “comprises,” “has,” “includes” or “contains” one or more elements possesses those one or more elements, but is not limited to possessing only those one or more elements. Likewise, an element of a system, device, or apparatus that “comprises,” “has,” “includes” or “contains” one or more features possesses those one or more features, but is not limited to possessing only those one or more features. The terms “proximal” and “distal” are used herein with reference to a clinician manipulating the handle portion of the surgical instrument. The term “proximal” refers to the portion closest to the clinician and the term “distal” refers to the portion located away from the clinician. It will be further appreciated that, for convenience and clarity, spatial terms such as “vertical”, “horizontal”, “up”, and “down” may be used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and/or absolute. Various exemplary devices and methods are provided for performing laparoscopic and minimally invasive surgical procedures. However, the reader will readily appreciate that the various methods and devices disclosed herein can be used in numerous surgical procedures and applications including, for example, in connection with open surgical procedures. As the present Detailed Description proceeds, the reader will further appreciate that the various instruments disclosed herein can be inserted into a body in any way, such as through a natural orifice, through an incision or puncture hole formed in tissue, etc. The working portions or end effector portions of the instruments can be inserted directly into a patient's body or can be inserted through an access device that has a working channel through which the end effector and elongate shaft of a surgical instrument can be advanced. A surgical stapling system can comprise a shaft and an end effector extending from the shaft. The end effector comprises a first jaw and a second jaw. The first jaw comprises a staple cartridge. The staple cartridge is insertable into and removable from the first jaw; however, other embodiments are envisioned in which a staple cartridge is not removable from, or at least readily replaceable from, the first jaw. The second jaw comprises an anvil configured to deform staples ejected from the staple cartridge. The second jaw is pivotable relative to the first jaw about a closure axis; however, other embodiments are envisioned in which the first jaw is pivotable relative to the second jaw. The surgical stapling system further comprises an articulation joint configured to permit the end effector to be rotated, or articulated, relative to the shaft. The end effector is rotatable about an articulation axis extending through the articulation joint. Other embodiments are envisioned which do not include an articulation joint. The staple cartridge comprises a cartridge body. The cartridge body includes a proximal end, a distal end, and a deck extending between the proximal end and the distal end. In use, the staple cartridge is positioned on a first side of the tissue to be stapled and the anvil is positioned on a second side of the tissue. The anvil is moved toward the staple cartridge to compress and clamp the tissue against the deck. Thereafter, staples removably stored in the cartridge body can be deployed into the tissue. The cartridge body includes staple cavities defined therein wherein staples are removably stored in the staple cavities. The staple cavities are arranged in six longitudinal rows. Three rows of staple cavities are positioned on a first side of a longitudinal slot and three rows of staple cavities are positioned on a second side of the longitudinal slot. Other arrangements of staple cavities and staples may be possible. The staples are supported by staple drivers in the cartridge body. The drivers are movable between a first, or unfired position, and a second, or fired, position to eject the staples from the staple cavities. The drivers are retained in the cartridge body by a retainer which extends around the bottom of the cartridge body and includes resilient members configured to grip the cartridge body and hold the retainer to the cartridge body. The drivers are movable between their unfired positions and their fired positions by a sled. The sled is movable between a proximal position adjacent the proximal end and a distal position adjacent the distal end. The sled comprises a plurality of ramped surfaces configured to slide under the drivers and lift the drivers, and the staples supported thereon, toward the anvil. Further to the above, the sled is moved distally by a firing member. The firing member is configured to contact the sled and push the sled toward the distal end. The longitudinal slot defined in the cartridge body is configured to receive the firing member. The anvil also includes a slot configured to receive the firing member. The firing member further comprises a first cam which engages the first jaw and a second cam which engages the second jaw. As the firing member is advanced distally, the first cam and the second cam can control the distance, or tissue gap, between the deck of the staple cartridge and the anvil. The firing member also comprises a knife configured to incise the tissue captured intermediate the staple cartridge and the anvil. It is desirable for the knife to be positioned at least partially proximal to the ramped surfaces such that the staples are ejected ahead of the knife. A surgical instrument1000is illustrated inFIG.1. As discussed in greater detail below, the surgical instrument1000is configured to clamp, incise, and seal patient tissue. The surgical instrument1000comprises an end effector1300, an articulation joint1400, and an articulation drive system1700(FIG.13) configured to articulate the end effector1300about the articulation joint1400. The end effector1300comprises a first jaw1310, a second jaw1320movable between an open position and a closed position, and a drive system1600(FIG.13) operable to close the second jaw1320during a closure stroke. After the end effector1300is closed, the drive system1600is operable once again to incise and staple the patient tissue captured between the first jaw1310and the second jaw1320during a firing stroke. Additionally, the surgical instrument1000comprises an energy delivery system1900which is also operable to seal the incised tissue. The surgical instrument1000further comprises a handle1100and a shaft1200extending from the handle1100. The handle1100comprises a grip1110extending downwardly from a handle body1120. As discussed in greater detail below, the handle1100further comprises a closure actuator1130operable to close the end effector1300and an articulation actuator1140operable to articulate the end effector1300relative to the shaft1200. The shaft1200comprises an outer housing1210and an inner frame, or spine,1230(FIG.4) which are rotatably mounted to the handle body1120about a rotation joint1220. Referring toFIG.5, the articulation joint1400comprises a flexible outer housing1410affixed to the outer housing1210and a flexible articulation frame1430connected to the shaft frame1230(FIG.4). The first jaw1310comprises a proximal end1311mounted to the flexible articulation frame1430via a pin forming a rotation joint1330between the first jaw1310and the second jaw1320. The distal end of the flexible articulation housing1410is also affixed to the first jaw1310via a clamp ring1420such that the end effector1300is affixed to the distal end of the articulation joint1400. Referring primarily toFIGS.1and13, the articulation drive system1700comprises an electric motor1710in communication with a control system of the surgical instrument1000. The control system is configured to supply power to the electric motor1710from a battery1180in response to an actuation of the articulation actuator1140. The articulation actuator1140comprises a switch that is actuatable in a first direction to operate the electric motor1710in a first direction and actuatable in a second direction to operate the electric motor1710in a second, or opposite, direction. The articulation drive system1700further comprises a transfer gear1730rotatably supported within the handle1100that is operably engaged with a gear output1720of the electric motor1710. Referring primarily toFIGS.2and4, the articulation drive system1700also comprises a first articulation actuator1740and a second articulation actuator1750operably engaged with the transfer gear1730. More specifically, the transfer gear1730comprises a pinion gear portion1735intermeshed with a first drive rack1745defined on the proximal end of the first articulation actuator1740and a second drive rack1755defined on the proximal end of the second articulation actuator1750. Owing to the positioning of the first drive rack1745and the second drive rack1755on opposite sides of the transfer gear1730, the first articulation actuator1740and the second articulation actuator1750are driven proximally and distally in opposition to, or antagonistically with respect to, one another when the transfer gear1730is rotated. For instance, the first articulation actuator1740is driven distally and the second articulation actuator1750is driven proximally to articulate the end effector1300in a first direction when the electric motor1710is operated in its first direction. Correspondingly, the first articulation actuator1740is driven proximally and the second articulation actuator1750is driven distally to articulate the end effector1300in a second, or opposite, direction when the electric motor1710is operated in its second direction. Referring toFIGS.4-6, the first jaw1310comprises a first articulation drive post1317extending upwardly on a first lateral side of the first jaw1310and a second articulation drive post1319extending upwardly on a second, or opposite, lateral side of the first jaw1310. The distal end of the first articulation actuator1740comprises a first drive mount1747engaged with the first articulation drive post1317and the distal end of the second articulation actuator1750comprises a second drive mount1759engaged with the second articulation drive post1319such that the proximal and distal movement of the articulation actuators1740and1750rotate the end effector1300about the articulation joint1400. When the end effector1300is articulated, the flexible outer housing1410and the flexible articulation frame1430of the articulation joint1400resiliently deflect to accommodate the rotation of the end effector1300. In various instances, the articulated position of the end effector1300is held in place due to friction within the articulation drive1700. In various embodiments, the articulation drive1700comprises an articulation lock configured to releasably hold the end effector1300in position. As discussed above, the surgical instrument1000comprises a drive system1600operable to close the end effector1300and then operable once again to staple and incise the patient tissue captured between the first jaw1310and the second jaw1320of the end effector1300. Referring again toFIG.13, the drive system1600comprises an electric motor1610in communication with the control system of the surgical instrument1000. The control system is configured to supply power to the electric motor1610from the battery1180in response to an actuation of the closure actuator1130. The closure actuator1130comprises a switch that is actuatable in a first direction to operate the electric motor1610in a first direction to close the end effector1300and actuatable in a second direction to operate the electric motor1610in a second, or opposite, direction to open the end effector1300. The closure drive system1600further comprises a transfer gear1630rotatably supported within the handle1100that is operably engaged with a gear output1620of the electric motor1610. The transfer gear1630is fixedly mounted to a rotatable drive shaft1660such that the drive shaft1660rotates with the transfer gear1630. The rotatable drive shaft1660extends through the shaft1200and comprises a flexible portion1665that extends through the articulation joint1400to accommodate the articulation of the end effector1300. The rotatable drive shaft1660further comprises a distal coupling1661that extends into a proximal end1311of the first jaw1310. In at least one embodiment, the distal coupling1661comprises a hex-shaped aperture, for example, but could comprise any suitable configuration. Referring primarily toFIG.6, the first jaw1310further comprises a channel1312extending between the proximal end1311and a distal end1313. The channel1312comprises two sidewalls extending upwardly from a bottom wall and is configured to receive a staple cartridge, such as a staple cartridge1500, for example, between the sidewalls. The staple cartridge1500comprises a cartridge body1510including a proximal end1511, a distal nose1513, and a tissue-supporting deck1512extending between the proximal end1511and the distal nose1513. The cartridge body1510further comprises a longitudinal slot1520defined therein extending from the proximal end1511toward the distal nose1513. The cartridge body1510also comprises longitudinal rows of staple cavities1530extending between the proximal end1511and the distal nose1513. More specifically, the cartridge body1510comprises a single longitudinal row of staple cavities1530positioned on a first lateral side of the longitudinal slot1520and a single longitudinal row of staple cavities1530positioned on a second, or opposite, lateral side of the longitudinal slot1520. That said, a staple cartridge can comprise any suitable number of longitudinal rows of staple cavities1530. The staple cartridge1500further comprises a staple removably stored in each staple cavity1530which is ejected from the staple cartridge1500during a staple firing stroke, as discussed in greater detail further below. Further to the above, referring again toFIG.6, the staple cartridge1500further comprises a drive screw1560rotatably supported in the cartridge body. More specifically, the drive screw1560comprises a proximal end1561rotatably supported by a proximal bearing in the proximal end1511of the cartridge body1510and a distal end1563rotatably supported by a distal bearing in the distal end1513of the cartridge body1510. The proximal end1561of the drive screw1560comprises a hex coupling extending proximally with respect to the proximal end1511of the cartridge end1510. When the staple cartridge1500is seated in the first jaw1310, the proximal end1511of the cartridge body1510is slid into the proximal end1311of the first jaw1310such that the hex coupling of the proximal drive screw end1561is inserted into and is operably engaged with the distal drive end1661of the rotatable drive shaft1660. Once the drive screw1560is coupled to the rotatable drive shaft1660the distal nose1513of the staple cartridge1500is seated in the distal end1313of the first jaw1310. That said, the staple cartridge1500can be seated in the first jaw1310in any suitable manner. In various instances, the staple cartridge1500comprises one or more snap-fit and/or press-fit features which releasably engage the first jaw1310to releasably secure the staple cartridge1500within the first jaw1310. To remove the staple cartridge1500from the first jaw1310, an upward, or lifting, force can be applied to the distal nose1513of the staple cartridge1500to release the staple cartridge1500from the first jaw1310. Referring again toFIG.6, the drive screw1560further comprises a threaded portion1565extending between the proximal end1561and the distal end1563and the staple cartridge1500further comprises a firing member1570threadably engaged with the threaded portion1565. More specifically, the firing member1570comprises a threaded nut insert1575threadably engaged with the threaded portion1565which is constrained, or at least substantially constrained, from rotating such that the firing member1570translates within the staple cartridge1500when the drive screw1560is rotated. When the drive screw1560is rotated in a first direction, the firing member1570translates from a proximal unactuated position to a distal actuated position during a closure stroke to move the second jaw1320from its open, or unclamped, position (FIG.7) to its distal, or clamped, position (FIGS.8and11). More specifically, the firing member1570comprises a first cam1572that engages the first jaw1310and a second cam1576that engages the second jaw1320during the closure stroke which co-operatively position the second jaw1320relative to the first jaw1310. At the outset of the closure stroke, the second cam1576is not engaged with the second jaw1320; however, the second cam1576comes into contact with a ramp1326(FIG.6) during the closure stroke to rotate the second jaw1320toward the first jaw1310. Once the firing member1570has reached the end of its closure stroke (FIGS.8and11), the controller of the surgical instrument1000stops the drive motor1610(FIG.13). At such point, referring toFIG.11, the firing member1570has not incised the patient tissue captured between the first jaw1310and the second jaw1320and/or stapled the patient tissue. If the clinician is unsatisfied with the positioning of the jaws1310and1320on the patient tissue, the clinician can release the closure actuator1130(FIG.1) to operate the drive motor1610in its second, or opposite, direction and translate the firing member1570proximally out of engagement with the second jaw1320. In at least one instance, the handle1100comprises a closure lock which releasably holds the closure actuator1130in its closed position and the clinician must deactivate the closure lock to reopen the closure actuator1130. Referring toFIG.1, the handle1100further comprises a closure lock release1160that, when actuated, unlocks the closure actuator1130. Once the end effector1300is open, the clinician can re-position the end effector1300relative to the patient tissue and, once satisfied with the re-positioning of the end effector1300relative to the patient tissue, close the closure actuator1130once again to re-operate the drive motor1610in its first direction to re-close the second jaw1320. At such point, the drive system1600can be operated to perform the staple firing stroke, as discussed further below. Further to the above, as illustrated inFIG.11, the firing member1570moves into contact with, or in close proximity to, a sled1550contained in the cartridge body1510at the end of the closure stroke. The surgical instrument1000further comprises a firing actuator in communication with the control system of the surgical instrument1000which, when actuated, causes the control system to operate the drive motor1610in its first direction to advance the firing member1570distally from its distal clamped position (FIGS.8and11) and push the sled1550through the staple firing stroke, as illustrated inFIG.12. In various embodiments, the staple cartridge1500comprises staple drivers which support and drive the staples out of the cartridge body1510when the staple drivers are contacted by the sled1550during the staple firing stroke. In other embodiments, as discussed in greater detail below, the staples comprise drivers integrally-formed thereon which are directly contacted by the sled1550during the staple firing stroke. In either event, the sled1550progressively ejects, or fires, the staples out of the cartridge body1510as the sled1550is moved from its distal clamped position (FIG.11) to its distal fired position (FIG.12) by the firing member1570. Moreover, referring toFIG.6, the firing member1570comprises a tissue cutting edge1571that moves through the longitudinal slot1520during the staple firing stroke to incise the tissue captured between the deck1512of the staple cartridge1500and the second jaw1320. Further to the above, the second jaw1320comprises a frame1325including a proximal end1321rotatably connected to the first jaw1310, a longitudinal recess1324, and a longitudinal slot1329configured to receive the firing member1570during the staple firing stroke. The frame1325further comprises a first longitudinal cam shoulder1327defined on a first side of the longitudinal slot1329and a second longitudinal cam shoulder1328defined on a second side of the longitudinal slot1329. During the staple firing stroke, the second cam1576of the firing member1570slides along the first longitudinal cam shoulder1327and the second longitudinal cam shoulder1328which co-operates with the first cam1572to hold the second jaw1320in position relative to the first jaw1310. The frame1325also comprises longitudinal rows of staple forming cavities defined therein which are registered with the staple cavities1530defined in the staple cartridge1500when the second jaw1320is in its closed position. The second jaw1320further comprises a cover, or cap,1322positioned in the longitudinal recess1324which is welded to the frame1325to enclose the longitudinal slot1329and extend over the second cam1576. The cover1322comprises a distal end, or nose,1323which is angled toward the distal nose1513of the staple cartridge1500. In various instances, the clinician can depress and hold the firing actuator until the staple firing stroke is completed. When the firing member1570reaches the end of the staple firing stroke, in such instances, the control system can automatically switch the operation of the drive motor1610from its first direction to its second direction to retract the firing member1570proximally back into its distal clamped position (FIGS.8and11). In such instances, the end effector1300remains in its closed, or clamped, configuration until the closure lock release1160(FIG.1) is actuated by the clinician to re-open the closure actuator1130and the end effector1300. In certain instances, the clinician can release the firing actuator prior to the end of the staple firing stroke to stop the drive motor1610. In such instances, the clinician can re-actuate the firing actuator to complete the staple firing stroke or, alternatively, actuate a retraction actuator in communication with the control system to operate the drive motor1610in its second direction to retract the firing member1570back into its distal clamped position (FIGS.8and11). In various alternative embodiments, the automatic retraction of the firing member1570and/or the actuation of the retraction actuator can retract the firing member1570back into is proximal unactuated position to automatically open the end effector1300without requiring the clinician to release the closure actuator1130. To move the second jaw1320into an open position (FIG.12A), the proximal end1321of the second jaw1320comprises a camming surface1339defined on the proximal end1321and the firing member1570comprises a cam portion1579defined on a proximal end of the firing member1570. The cam portion1579is configured to pivot the second jaw1320into the open position upon contacting the camming surface1339. Once the staple cartridge1500has been at least partially expended, i.e., at least partially fired, and the end effector1500has been re-opened, the staple cartridge1500can be removed from the first jaw1310and replaced with another staple cartridge1500, and/or any other suitable staple cartridge. If the expended staple cartridge1500is not replaced, the firing drive1600is locked out from performing another staple firing stroke. Such a lockout can comprise an electronic lockout that prevents the control system from operating the drive motor1610to perform another staple firing stroke until the spent staple cartridge1500is replaced with an unspent staple cartridge. In addition to or in lieu of an electronic lockout, the surgical instrument1000can include a mechanical lockout which blocks the distal advancement of the firing member1570through another staple firing stroke unless the spent staple cartridge1500is replaced. Notably, referring toFIG.12, the sled1550is not retracted proximally with the firing member1570after the staple firing stroke. As such, the electronic and/or mechanical lockout can key off of the position of the sled1550at the outset of the staple firing stroke. Stated another way, the staple firing stroke is prevented or blocked if the sled1550is not in its unfired position when the staple firing stroke is initiated. The entire disclosures of U.S. Pat. No. 7,143,923, entitled SURGICAL STAPLING INSTRUMENT HAVING A FIRING LOCKOUT FOR AN UNCLOSED ANVIL, which issued on Dec. 5, 2006; U.S. Pat. No. 7,044,352, SURGICAL STAPLING INSTRUMENT HAVING A SINGLE LOCKOUT MECHANISM FOR PREVENTION OF FIRING, which issued on May 16, 2006; U.S. Pat. No. 7,000,818, SURGICAL STAPLING INSTRUMENT HAVING SEPARATE DISTINCT CLOSING AND FIRING SYSTEMS, which issued on Feb. 21, 2006; U.S. Pat. No. 6,988,649, SURGICAL STAPLING INSTRUMENT HAVING A SPENT CARTRIDGE LOCKOUT, which issued on Jan. 24, 2006; and U.S. Pat. No. 6,978,921, SURGICAL STAPLING INSTRUMENT INCORPORATING AN E-BEAM FIRING MECHANISM, which issued on Dec. 27, 2005, are incorporated by reference herein. In various alternative embodiments, a surgical instrument can comprise separate and distinct closure and staple firing drive systems. In at least one such embodiment, the closure drive system comprises a closure actuator and a closure drive motor which, when actuated, moves the closure actuator distally through a closure stroke to close the end effector. In such embodiments, the staple firing drive system comprises a firing actuator and a separate firing drive motor which moves the firing actuator distally through a staple firing stroke. As discussed in greater detail below, the length of the closure stroke in such embodiments can be adjusted independently of the staple firing stroke to control the position of the second jaw1320. Moreover, the closure drive system can also be actuated during the staple firing stroke to further control the position of the second jaw1320. As discussed above, the staples ejected from the staple cartridge1500can seal the incised patient tissue. That said, a single row of staples on each side of the incision may not be able to create a sufficient hemostatic seal in the incised patient tissue. To this end, as discussed in greater detail below, the surgical instrument1000is further configured to use electrical energy to seal the patient tissue. Referring toFIG.1, the surgical instrument1000further comprises an energy delivery system1900including an off-board power supply and a cord1990in communication with the off-board power supply. In various alternative embodiments, the energy delivery system1900comprises an on-board power supply, such as the battery1180, for example. In either event, the control system of the surgical instrument1000is configured to control the delivery of energy from the energy delivery system1900to the patient tissue, as discussed in greater detail below. The energy delivery system1900comprises an electrical circuit extending through the shaft1200and the articulation joint1400and into the end effector1300. Referring toFIG.6, the energy delivery system1900comprises an electrode supply circuit1920that extends into the second jaw1320and comprises a longitudinal electrode1925mounted to the frame1325of the second jaw1320. The longitudinal electrode1925is electrically insulated from the metal frame1325such that the current flowing through the longitudinal electrode1925, or at least a majority of the current flowing through the longitudinal electrode1925, flows into a longitudinal return electrode1590of the staple cartridge1500. The longitudinal return electrode1590is seated in the cartridge body1510and comprises a cartridge connector1595that engages, and makes an electrical connection with, a circuit connector1915of an electrode return circuit1910when the staple cartridge1500is seated in the first jaw1310. In various alternative embodiments, the staple cartridge1500includes a supply electrode and the second jaw1320includes a return electrode. Referring toFIG.1, the surgical instrument1000further comprises a display1190in communication with the control system of the surgical instrument1000. In various instances, the control system is configured to display parameters and/or data regarding the staple firing system and/or the energy delivery system. A surgical instrument2000is illustrated inFIG.14. The surgical instrument2000comprises an end effector2300and a firing drive2600. The end effector2300comprises a first jaw2310and a second jaw2320rotatable relative to the first jaw2310about a pivot2330. The first jaw2310comprises a replaceable staple cartridge2500comprising staples removably stored therein and the second jaw2320comprises an anvil configured to deform the staples. The firing drive2600comprises a firing member2570that is advanced distally to push a sled contained in the staple cartridge2500during a staple firing stroke to drive the staples toward the second jaw2320. The firing member2570comprises a first cam2572configured to engage a longitudinal cam shoulder2312defined in the first jaw2310and a second cam2576configured to engage a longitudinal cam shoulder2327defined in the second jaw2320during the staple firing stroke which co-operatively hold the second jaw2320in position relative to the first jaw2310. The firing member2570further comprises a tissue cutting edge2571configured to incise the patient tissue captured between the staple cartridge2500and the second jaw2320during the staple firing stroke. Further to the above, the firing drive2600further comprises a rotatable drive shaft2660engaged with a rotatable drive shaft2560extending within the staple cartridge2500. The rotatable drive shaft2660comprises a threaded portion2665that is rotatably supported in the first jaw2310by a threaded bearing2315. As a result of the interaction between the threaded portion2665of the drive shaft2660and the threaded bearing2315, the rotation of the drive shaft2660causes the drive shaft2660to translate proximally or distally relative to the end effector2300depending on the direction in which the drive shaft2660is rotated. When the drive shaft2560is rotated in a first direction, the drive shaft2660translates distally. When the drive shaft2560is rotated in a second, or opposite, direction, the drive shaft2660translates proximally. As discussed in greater detail below, the rotation and translation of the drive shaft2660is transmitted to the rotatable drive shaft2560. Further to the above, the firing member2570comprises a threaded aperture2575defined therein that is threadably engaged with a threaded portion2565of the rotatable drive shaft2560. When the drive shaft2560is rotated in the first direction by the drive shaft2660as described above, referring toFIG.15, the firing member2570translates distally relative to the drive shaft2560. Thus, the distal motion of the firing member2570relative to the end effector2300is a composition of two concurrent distal translations—the translation of the drive shaft2560relative to the end effector2300and the translation of the firing member2570relative to the drive shaft2560. When the drive shaft2560is rotated in the second, or opposite, direction by the drive shaft2660as also described above, the firing member2570translates proximally relative to the drive shaft2560. Thus, the proximal motion of the firing member2570relative to the end effector2300is a composition of two concurrent proximal translations—the translation of the drive shaft2560relative to the end effector2300and the translation of the firing member2570relative to the drive shaft2560. To achieve the above, the threaded portion2565and the threaded portion2665can comprise any suitable thread design including, for example, right-handed threads and/or left-handed threads. As discussed above, the drive shaft2560translates distally relative to the end effector2300and, also, the firing member2570translates distally relative to the drive shaft2560during the staple firing stroke. In various instances, the drive shaft2560translates relative to the end effector2300at a first translational rate and the firing member2570translates distally relative to the drive shaft2560at a second translational rate. In at least one embodiment, the first translational rate and the second translational rate are the same, i.e., the firing member2570translates distally relative to the end effector2300at a speed which is twice that of the distal translation of the drive shaft2560relative to the end effector2300. In at least one such embodiment, the threaded portion2665of the drive shaft2660comprises a first thread pitch and the threaded portion2565of the drive shaft2560comprises a second thread pitch which is the same as the first thread pitch. In at least one such embodiment, the threaded portion2665of the drive shaft2660comprises a first threads-per-inch (TPI) and the threaded portion2565of the drive shaft2560comprises a second threads-per-inch which is the same as the first threads-per-inch. In various embodiments, further to the above, the first translational rate of the drive shaft2560relative to the end effector2300is faster than the second translational rate of the firing member2570relative to the drive shaft2560. In other embodiments, the first translational rate of the drive shaft2560relative to the end effector2300is slower than the second translational rate of the firing member2570relative to the drive shaft2560. In either instance, however, the speed of the firing member2570relative to the end effector2300is faster than the speed of the drive shaft2560relative to the end effector2300. In various embodiments, the first thread pitch of the threaded portion2665and the second thread pitch of the threaded portion2565are different. Likewise, in various embodiments, the first threads-per-inch of the threaded portion2665is different than the second threads-per-inch of the threaded portion2565. When the second translational rate of the firing member2570relative to the drive shaft2560is faster than the first translational rate of the drive shaft2560relative to the end effector2300, the second threads-per-inch of the threaded portion2565is smaller than the first threads-per-inch of the threaded portion2665, for example. Likewise, the second threads-per-inch of the threaded portion2565is larger than the first threads-per-inch of the threaded portion2665when the second translational rate of the firing member2570relative to the drive shaft2560is slower than the first translational rate of the drive shaft2560relative to the end effector2300, for example. In various embodiments, the first thread pitch of the threaded portion2665is constant along the length thereof. Thus, for a given speed of the electric motor driving the drive system2600, the drive shaft2660will translate at a constant speed relative to the end effector2300. In other embodiments, the first thread pitch of the threaded portion2665is not constant along the length thereof. In at least one such embodiment, the first thread pitch changes along the length of the threaded portion2665and, for a given speed of the electric motor driving the drive system2600, the translational speed of the drive shaft2660relative to the end effector2300changes during the staple firing stroke. Such an arrangement can be useful to create a soft start of the firing member2570at the beginning of the staple firing stroke and/or a soft stop of the firing member2570at the end of the staple firing stroke. In such instances, the first translational rate of the drive shaft2660is slower at the beginning and/or at the end of the staple firing stroke. In various embodiments, further to the above, the second thread pitch of the threaded portion2565is constant along the length thereof. Thus, for a given speed of the electric motor driving the drive system2600, the firing member2570will translate at a constant speed relative to the drive shaft2560. In other embodiments, the second thread pitch of the threaded portion2565is not constant along the length thereof. In at least one such embodiment, the second thread pitch changes along the length of the threaded portion2565and, for a given speed of the electric motor driving the drive system2600, the translational speed of the firing member2570relative to the drive shaft2560changes during the staple firing stroke. Such an arrangement can be useful to create a soft start of the firing member2570at the beginning of the staple firing stroke and/or a soft stop of the firing member2570at the end of the staple firing stroke. In such instances, the second translational rate of the firing member2570is slower at the beginning and/or at the end of the staple firing stroke. A surgical instrument3000is illustrated inFIG.16. The surgical instrument3000comprises an end effector3300, a closure drive3800, and a firing drive3600. The end effector3300comprises a first jaw3310and a second jaw3320rotatable relative to the first jaw3310about a pivot3330. The second jaw3320is movable from an open position to a closed position by the closure drive3800during a closure stroke, as discussed in greater detail below. The first jaw3310comprises a staple cartridge3500including staples removably stored therein and the second jaw3320comprises forming pockets configured to deform the staples. Once the second jaw3320is in its closed position, as illustrated inFIG.16, the firing drive3600is operable to fire the staples from the staple cartridge3500to staple the patient tissue captured between the staple cartridge3500and the second jaw3320, as also described in greater detail below. Further to the above, the closure drive3800comprises a closure member3870which is movable distally to engage the second jaw3320and move the second jaw3320into its closed position during the closure stroke. The closure member3870comprises a first cam3872configured to engage a first longitudinal shoulder3312defined in the first jaw3310and a second cam3876configured to engage the second jaw3320during the staple firing stroke. Referring toFIGS.17and18, the second jaw3320comprises an anvil plate3325and a cover, or cap,3322welded to the anvil plate3325. The anvil plate3325comprises a ramp3326and a longitudinal slot3329defined therein configured to receive the closure member3870. At the beginning of the closure stroke, the second cam3876of the closure member3870is not in contact with the ramp3326. Once the closure stroke is initiated, however, the second cam3876comes into contact with the ramp3326and begins to close the second jaw3320. As the closure stroke progresses, the second cam3876slides onto longitudinal shoulders3327and3328defined on the lateral sides of the longitudinal slot3329. At such point, the first cam3872and the second cam3876co-operatively hold the second jaw3320in its closed position. Referring again toFIG.16, the anvil33200comprises tissue stops3340extending downwardly therefrom which prevent, or at least inhibit, patient tissue from migrating into the proximal end of the end effector3300. Each tissue stop3340comprises a distal edge3345which co-operates with the lateral sides of the first jaw3310to prevent, or at least inhibit, the patient tissue from moving proximally. At the end of the closure stroke, referring again toFIG.16, the leading edge3871of the closure member3870is positioned proximally with respect to the distal edges3345of the tissue stops3340. After the closure stroke, as mentioned above, the firing drive3600can be actuated to fire the staples and incise the patient tissue during a staple firing stroke. The firing drive3600comprises a firing bar3670which is advanced distally to push a sled3550positioned in the staple cartridge3500through the staple firing stroke and drive the staples stored within the staple cartridge3500toward the second jaw3320. The firing bar3670further comprises a tissue cutting edge3675which extends into the longitudinal slot3329defined in the second jaw3320and passes through the tissue gap defined between the second jaw3320and the staple cartridge3500during the staple firing stroke to incise the patient tissue as it is being stapled. Notably, further to the above, the firing bar3670does not comprise cams which engage the first jaw3310and the second jaw3320to hold the second jaw3320in position during the staple firing stroke. In such embodiments, the position of the second jaw3320relative to the first jaw3310is controlled solely by the closure drive3800which is operated independently of the firing drive3600. Thus, in various instances, the control system of the surgical instrument3000can modify the operation of the closure drive3800independently of modifying the operation of the firing drive3600to achieve a desired goal and/or therapeutic effect. For instance, the control system can operate the closure drive3800to further close the second jaw3320while the firing drive3600is being operated to perform the staple firing stroke. In such instances, the control system can increase the clamping force being applied to the patient tissue during the staple firing stroke to improve staple formation. In other instances, the control system can operate the closure drive3800to relax the clamping pressure being applied to the patient tissue during the staple firing stroke. In such instances, the control system can prevent the overcompression of the patient tissue and/or keep the forming pockets in the second jaw3320in registration with the staples being ejected from the staple cartridge3500. Other embodiments are envisioned in which the firing bar3670comprises a first cam for engaging the first jaw3310during the staple firing stroke, but not a second cam engaged with the second jaw3320. In various alternative embodiments, the firing bar3670can comprise both a first cam engaged with the first jaw3310and a second cam engaged with the second jaw3320during the staple firing stroke. In such embodiments, both the firing drive3600and the closure drive3800can be used to control the position of the second jaw3320but at different locations within the end effector3300. Further to the above, the surgical instrument3000comprises a handle including a jaw adjustment actuator and/or touch screen control in communication with the control system of the surgical instrument3000. In various embodiments, the control system comprises one or more sensors configured to detect the firing load in the firing drive3600during the staple firing stroke. In at least one such embodiment, the control system comprises a current sensor configured to detect the magnitude of current through the electric motor of the firing drive3600—which is a proxy for the firing load in the firing drive3600—and adjust the position of the second jaw3320based on the magnitude of the current detected through the electric motor. In certain embodiments, the control system comprises a load cell sensor and/or a strain gauge sensor, for example, configured to detect the clamping force being applied to the patient tissue and adjust the position of the second jaw3320based on the voltage potential output of the load cell sensor and/or strain gauge sensor. In various embodiments, the control system is configured to automatically adjust the position of the second jaw3320. In other embodiments, the control system is configured to provide the clinician using the surgical instrument3000with the option of modifying the position of the second3320. In at least one such embodiment, the control system is configured to illuminate the jaw adjustment actuator, or present an actuatable input on the touch screen control, when the firing load in the firing drive3600and/or the clamping load in the closure drive3800has crossed a threshold and, when the actuator is actuated by the clinician, adjust the position of the second jaw3320. As discussed above, the closure drive3800is operable during the staple firing stroke to adjust the position of the closure member3870. Thus, the closure member3870is movable distally during a first closure stroke to close the second jaw3320and then a second closure stroke to control the position of the second jaw3320during the staple firing stroke. Further to the above, referring again toFIG.16, the closure member3870is movable distally into a first closed position as a result of the first closure stroke in which the closure member3870is positioned proximally with respect to the distal edges3345of the tissue stops3340. As a result of the second closure stroke, at least a portion of the closure member3870is moved distally beyond the distal edges3345of the tissue stops3340to a second closed position. In such a second closed position, the closure member3870can better resist the upward movement and/or deflection of the second jaw3320during the staple firing stroke. The above being said, various embodiments are envisioned in which the closure member3870does not move distally beyond the distal edges3345of the tissue stops3340during the second closure stroke. Referring again toFIG.16, the firing bar3670extends distally past the closure member3870. More specifically, the firing bar3670is positioned laterally with respect to the closure member3870along the length of the closure member3870and then extends distally in front of the closure member3870such that the firing bar3670is laterally centered, or at least substantially laterally centered, within the end effector3300. As a result, the tissue cutting edge3675is aligned, or at least substantially aligned, with the longitudinal slot of the end effector3300. An alternative arrangement is illustrated inFIGS.19and20which comprises a firing drive including a first firing bar3670a′ that extends alongside a first lateral side of a closure member3870′ and a second firing bar3670b′ that extends alongside a second, or opposite, lateral side of the closure member3870′.FIG.19is a cross-sectional view of this arrangement taken proximally with respect to the end effector of the surgical instrument andFIG.20is a cross-sectional view of this arrangement taken within the end effector. The closure member3870′ comprises a longitudinal bar extending between the firing bars3670a′ and3670b′ (FIG.19) and, also, first and second cams3872′ and3876′ (FIG.20) which are configured to engage the first and second jaws3310and3320, respectively, during a firing stroke. Notably, the height of the firing bars3670a′ and3670b′ are shortened to fit between the first and second cams3872′ and3876′ such that the firing bars3670a′ and3670b′ extend further into the end effector. The distal ends of the firing bars3670a′ and3670b′ are connected at a location which is distal to the closure member3870′ such that the firing bars3670a′ and3670b′ co-operatively support a tissue cutting knife and/or firing member during the firing stroke. A surgical instrument4000is illustrated inFIG.21. The surgical instrument4000comprises an end effector4300including a first jaw4310and a second jaw4320. The first jaw4310is rotatable relative to the second jaw4320between an open position and a closed position. The first jaw4310comprises a replaceable staple cartridge4500seated therein which comprises a cartridge body, a longitudinal slot4520defined in the cartridge body, a longitudinal row of staple cavities4530defined on each side of the longitudinal slot4520, and staples removably stored in the staple cavities4530. The staple cartridge4500further comprises an electrical circuit including one or more electrodes4590which are operable to seal the patient tissue as described in greater detail below. Further to the above, the first jaw4310comprises a longitudinal cam slot4312defined therein and the second jaw4320comprises longitudinal cam shoulders4327and4328defined on opposite sides of a longitudinal slot4329. The closure drive of the surgical instrument4000comprises a closure member4870comprising a C-shaped channel including a base, or spine,4877, a first cam4872extending from the spine4877, and a second cam4876extending from the spine4877. The first cam4872is configured to extend into the cam slot4312of the first jaw4310and the second cam4876is configured to engage the longitudinal shoulder4328defined in the second jaw4320during a closure stroke to move the first jaw4310from an open, unclamped, position to a closed, clamped, position. The firing drive of the surgical instrument comprises a firing member4670comprising a C-shaped channel including a base, or spine,4677, a first cam4672extending from the spine4677, and a second cam4676extending from the spine4677. The first cam4672is configured to extend into the cam slot4312of the first jaw4310and the second cam4676is configured to engage the longitudinal shoulder4327defined in the second jaw4320during a staple firing stroke to eject the staples from the staple cartridge4500. Notably, the spines4677and4877both extend within the longitudinal slot4520defined in the staple cartridge4500and the longitudinal slot4329defined in the second jaw4320and are arranged in a back-to-back arrangement which permits the firing member4670and the closure member4870to slide relative to one another. A portion of a staple cartridge5500is illustrated inFIGS.22-24. The staple cartridge5500comprises a cartridge body5510including staple cavities5530defined therein and staples5540positioned in the staple cavities5530. Each staple5540comprises a base5541, a first leg5542extending from the base5541, and a second leg5544extending from the base5541. Moreover, each staple5540comprises an integral driver portion that is directly engaged by a sled during a staple firing stroke which is discussed in greater detail below in connection withFIG.33. Each staple cavity5530comprises a central guide portion5531configured to guide the base5541of a staple5540, a first end5532configured to guide the first leg5542of the staple5540, and a second end5534configured to guide the second leg5544of the staple5540when the staple5540is lifted from an unfired position (FIG.23) to a fired position (FIG.24). As the staple5540is being fired, the first leg5542and the second leg5544contact forming pockets defined in an anvil positioned opposite the staple cartridge5500and are deformed generally inwardly, i.e., generally toward one another into a formed configuration, such as a B-shaped configuration, for example. In various instances, further to the above, the staple5540may become malformed during the staple forming process. For instance, one or both of the staple legs5542and5544may deform outwardly instead of inwardly during the staple forming process. While such outward deformation of the legs5542and5544may be acceptable in some circumstances, such malformation may not be desirable to some clinicians. To prevent, or at least inhibit, the malformation of the staple legs5542and5544, the staple5540and the staple cavity5530comprise co-operating features which bias the staple legs5542and5544inwardly during the staple forming process, as described in greater detail below. Referring primarily toFIG.24, the staple cavity5530comprises a first cam5533and the staple5540comprises a first cam shoulder5543which engages the first cam5533as the staple5540is lifted upwardly toward the anvil. When the first cam shoulder5543contacts the first cam5533, the first leg5542is pushed inwardly, i.e., toward the second leg5544. In various instances, the first cam5533and the first cam shoulder5543are configured and arranged such that first cam shoulder5543contacts the first cam5533prior to the first leg5542contacting the anvil forming pocket registered with the first leg5542. In such instances, the first leg5542has inward momentum when the first leg5542contacts the anvil which, as a result, facilitates the proper deformation of the staple5540. In other instances, the first cam5533and the first cam shoulder5543are configured and arranged such that first cam shoulder5543contacts the first cam5533at the same time that the first leg5542contacts the anvil forming pocket registered with the first leg5542. In such instances, the anvil forming pocket and the first cam5533co-operatively provide two points of contact for the first staple leg5542as the first staple leg5542is being deformed. In various other instances, the first cam5533and the first cam shoulder5543are configured and arranged such that first cam shoulder5543contacts the first cam5533after the first leg5542contacts the anvil forming pocket registered with the first leg5542. Referring primarily toFIG.24, the staple cavity5530further comprises a second cam5535and the staple5540further comprises a second cam shoulder5545which engages the second cam5535as the staple5540is lifted upwardly toward the anvil. When the second cam shoulder5545contacts the second cam5535, the second leg5544is pushed inwardly, i.e., toward the first leg5542. In various instances, the second cam5535and the second cam shoulder5545are configured and arranged such that second cam shoulder5545contacts the second cam5535prior to the second leg5544contacting the anvil forming pocket registered with the second leg5544. In such instances, the second leg5544has inward momentum when the second leg5544contacts the anvil which, as a result, facilitates the proper deformation of the staple5540. In other instances, the second cam5535and the second cam shoulder5545are configured and arranged such that second cam shoulder5545contacts the second cam5535at the same time that the second leg5544contacts the anvil forming pocket registered with the second leg5544. In such instances, the anvil forming pocket and the second cam5535co-operatively provide two points of contact for the second staple leg5544as the second staple leg5544is being deformed. In various other instances, the second cam5535and the second cam shoulder5545are configured and arranged such that second cam shoulder5545contacts the second cam5535after the second leg5544contacts the anvil forming pocket registered with the second leg5544. A portion of a staple cartridge6500is illustrated inFIGS.25-27. The staple cartridge6500comprises a cartridge body5510including staple cavities5530defined therein and staples6540positioned in the staple cavities5530. Each staple6540comprises a base6541, a first leg6542extending from the base6541, and a second leg6544extending from the base6541. Moreover, each staple6540comprises an integral driver portion that is directly engaged by a sled during a staple firing stroke. Further to the above, the first leg6542of the staple6540comprises an arcuate portion6543defined therein which is configured to contact the first cam5533as the staple6540is moved into its fired position. Similarly, the second leg6544of the staple6540comprises an arcuate portion6545defined therein which is configured to contact the second cam5535as the staple6540is moved into its fired position. The arcuate portion6543of the first leg6542and the arcuate portion6545of the second leg6544are cut-out during the stamping process. That said, various alternative embodiments are envisioned in which the arcuate portions6543and6545are bent into the staple legs6542and6544, respectively, during a secondary forming process. A portion of a staple cartridge7500is illustrated inFIGS.28and29. The staple cartridge7500comprises a cartridge body5510including staple cavities5530defined therein and staples7540positioned in the staple cavities5530. Each staple7540comprises a base7541, a first leg7542extending from the base7541, and a second leg7544extending from the base7541. Moreover, each staple7540comprises an integral driver portion that is directly engaged by a sled during a staple firing stroke. Further to the above, the first leg7542of the staple7540comprises a bump7543defined therein which is configured to contact the first cam5533as the staple7540is moved into its fired position. Similarly, the second leg7544of the staple7540comprises a bump7545defined therein which is configured to contact the second cam5535as the staple7540is moved into its fired position. The bump7543of the first leg7542and the bump7545of the second leg7544are cut-out during the stamping process. A portion of a staple cartridge8500is illustrated inFIGS.30-32. The staple cartridge8500comprises a cartridge body5510including staple cavities5530defined therein and staples8540positioned in the staple cavities5530. Each staple8540comprises a base8541, a first leg8542extending from the base8541, and a second leg8544extending from the base8541. Moreover, each staple8540comprises an integral driver portion that is directly engaged by a sled during a staple firing stroke. Further to the above, the first leg8542of the staple8540comprises an angled shoulder8543defined therein which is configured to contact the first cam5533as the staple8540is moved into its fired position. Similarly, the second leg8544of the staple8540comprises an angled shoulder8545defined therein which is configured to contact the second cam5535as the staple8540is moved into its fired position. The angled shoulder8543of the first leg8542and the angled shoulder8545of the second leg8544are cut-out during the stamping process. Moreover, the first leg8542and the second leg8544of the staple8540comprise notches or cut-outs8549defined therein which are configured to induce the legs8542and8544to bend inwardly, or at least substantially toward one another, during the staple forming process and assume a desired formed configuration. A stamped staple100is depicted inFIG.33. The staple100comprises a proximal staple leg110, a distal staple leg120, and a staple base portion130. The staple100further comprises vertical transition portions, or bends,118,128and lateral transition portions, or bends,116,126. The vertical transition portions118,128bend, or extend, the legs110,120vertically, or upward, from the staple base portion130. The lateral transition portions116,126extend the staple legs110,120laterally outward, or at least substantially perpendicularly with respect to the staple base portion130. The staple legs110,120define a first plane and the staple base130defines a second plane. Together, the vertical transition portions118,128and the lateral transition portions116,126permit the staple legs110,120to be laterally offset and parallel with respect to the staple base portion130. Stated another way, the first plane is offset from and at least substantially parallel to the second plane. InFIG.33, the first plane is offset in a negative Y direction, which is orthogonal to a vertical Z direction. Other staples may be used in conjunction with a plurality of staples100where the other staples comprise a first plane which is offset in the positive Y direction. The use of both types of staples permits staple rows to be nested, or interwoven, where staple legs of neighboring rows may be at least substantially aligned and/or share a common longitudinal axis. In various instances, the staple rows can be nested to provide denser staple rows. Further to the above, the proximal staple leg110comprises a generally rectangular cross-section including flat surfaces and corners. The corners of the cross-section comprise bevels, radiuses, and/or coined edges114which reduce the exposure of sharp edges to the patient tissue. That said, the proximal staple leg110comprises a sharp tip112configured to incise the patient tissue. Similarly, the distal staple leg120comprises a generally rectangular cross-section including flat surfaces125and corners124which are beveled, radiused, and/or coined to reduce the exposure of sharp edges to the patient tissue. Like the proximal leg110, the distal staple leg120comprises a sharp tip122configured to incise the patient tissue. The staple base130comprises an upper portion136configured to contact and support patient tissue. The upper portion136of the staple base130comprises tissue contacting surfaces137,138, and139and edges134which are beveled, radiused, and/or coined to reduce the exposure of the sharp edges to the patient tissue. The staple base130further comprises a lower portion135which includes a drive cam132configured to be directly engaged by a sled. The lower portion135further comprises a bottom edge131which rides over the apex of a sled rail and a distal shoulder133which loses contact with the sled rail as the sled moves distally. Further to the above, the legs110and120of the staple100extend in a first plane and the drive cam132of the staple100is defined in a second plane. The second plane is parallel to, or at least substantially parallel to, the first plane. When the legs110and120are deformed, the legs110and120capture patient tissue within the staple100outside of the second plane. Among other things, such an arrangement allows a larger volume of tissue to be captured within the staple100as compared to wire staples that are defined in a single plane. That said, such wire staples are desirable in many instances and, in some instances, can be used in conjunction with stamped staples. The entire disclosures of U.S. patent application Ser. No. 14/318,996, entitled FASTENER CARTRIDGES INCLUDING EXTENSIONS HAVING DIFFERENT CONFIGURATIONS, now U.S. Patent Application Publication No. 2015/0297228, U.S. patent application Ser. No. 15/385,907, entitled SURGICAL INSTRUMENT SYSTEM COMPRISING AN END EFFECTOR LOCKOUT AND A FIRING ASSEMBLY LOCKOUT, now U.S. Patent Application Publication No. 2018/0168608, and U.S. patent application Ser. No. 15/191,775, entitled STAPLE CARTRIDGE COMPRISING WIRE STAPLES AND STAMPED STAPLES, now U.S. Patent Application Publication No. 2017/0367695 are incorporated by reference herein. A staple cartridge9500is illustrated inFIGS.34-38. The staple cartridge9500comprises a cartridge body9510including a proximal end9511and a distal nose9513. The cartridge body9510further comprises a deck9512, a longitudinal slot9520extending from said proximal end9511toward the distal nose9513, and longitudinal rows of staple cavities9530defined in the deck9512extending between the proximal end9511and the distal nose9513. The cartridge body9510also comprises longitudinal tissue compression rails9515and9516extending upwardly from the deck9512. The longitudinal compression rail9515extends along a first side of the longitudinal slot9520and the longitudinal compression rail9516extends along a second, or opposite, side of the longitudinal slot9520. Further to the above, referring primarily toFIGS.37and38, the staple cartridge9500further comprises a staple9540stored in each staple cavity9530and staple drivers9580which support and drive the staples9540out of the staple cavities9530during a staple firing stroke. In this embodiment, each staple driver9580only supports and drives one staple9540, but other embodiments are envisioned in which a staple driver supports and drives more than one staple. The staple cartridge9500also comprises a sled9550which progressively contacts the staple drivers9580and lifts the staple drivers9580and staples9540within their respective staple cavities9530as the sled9550is moved distally during the staple firing stroke. Further to the above, the sled9550is pushed distally by a tissue cutting knife of a drive system during the staple firing stroke. After the staple firing stroke has been completed and/or otherwise stopped, the tissue cutting knife is retracted back into its unfired position. Notably, the sled9550is not retracted proximally and is instead left in its distal fired position. Such an arrangement can be used as part of a spent cartridge/missing cartridge firing lockout, as discussed above. Further to the above, the staple cartridge9500comprises an electrode circuit9590. The electrode circuit9590comprises an electrical connector9595configured to engage a corresponding electrical connector in a surgical instrument when the staple cartridge9500is seated in the surgical instrument. The electrode circuit further comprises a longitudinal row of electrode contacts9594positioned in apertures defined in the longitudinal tissue compression rail9516and a flex circuit9592and conductor bar9596electrically connecting the electrode contacts9594to the electrical connector9595. As discussed herein, electrical power is supplied to the electrode circuit9590to seal the patient tissue in co-operation with the staples9540. Further to the above, referring primarily toFIG.38, each staple9540of the staple cartridge9500comprises a base9541and legs9542extending from the base9541. Each staple driver9580comprises a seat9581slideably positioned in a staple cavity9530which is configured to receive and support the base9541of a staple9540positioned in the staple cavity9530. The seat9581of the staple driver9580is sized and configured such that it is closely received within its staple cavity9530. As a result, the movement of the staple driver9580is constrained, or at least substantially constrained, to upward movement toward the anvil positioned opposite the staple cartridge9500during the staple firing stroke. As such, the lateral movement, longitudinal movement, and/or rotation of the staple driver9580within the staple cavity9530is prevented, or at least limited, owing to the close fit therebetween. In addition, each staple driver9580comprises a lateral support9589slideably positioned within a support cavity9539defined in the cartridge body9510. The lateral supports9589of the staple drivers9580extend inwardly and above the seats9581and are sized and configured such that the lateral supports9589are closely received within the support cavities9539. As a result, the lateral supports9589prevent, or at least limit, lateral movement, longitudinal movement, and/or rotation of the staple drivers9580within the staple cavities9530. In at least one embodiment, the lateral supports9589extend into cavities defined under the longitudinal compression rails9515and9516when the staple drivers9580are in their fired positions, as illustrated inFIG.39. Moreover, the lateral supports9589of one row of the staple drivers9580are positioned under the electrode contacts9594when the staple drivers9580are in their fired positions. A staple cartridge10500is illustrated inFIGS.39-41and is similar to the staple cartridge9500in many respects which are not discussed herein for the sake of brevity. The staple cartridge10500comprises a cartridge body10510and longitudinal rows of staple cavities10530defined therein. The staple cartridge10500further comprises longitudinal rows of staple drivers10580configured to fire the staples positioned in the staple cavities10530. Each staple driver10580comprises a staple seat slideably positioned in a staple cavity10530, a lateral support10539slideably positioned in a support cavity10589, and a drive surface, or cam,10585positioned intermediate the staple seat and the lateral support10539. The drive cams10585of a longitudinal row of staple drivers10580are aligned, or at least substantially aligned, with one another longitudinally such that a ramp of a sled can sequentially engage all of the drive cams10585during the staple firing stroke. The staple drivers10580are driven from an unfired, or low, position (FIG.40) to a fired, or raised, position (FIGS.39and41) by the sled during the staple firing stroke. In various instances, the staple drivers10580, and the staples supported thereon, may accidentally be displaced upwardly within the staple cavities10530while the staple cartridge10500is being handled and/or inserted into the stapling instrument. To prevent, or at least inhibit, this from happening, each staple driver10580comprises a latch10588which is releasably engaged within a lock window10517defined in the cartridge body10510when the staple drivers10580are in their unfired positions. When the sled contacts the staple drivers10580, however, the latches10588release from the lock windows10517which permits the staple drivers10580to be lifted into their fired positions. Moreover, the latch10588can engage a lock shoulder10518defined in the cartridge body10510to hold the staple driver10580in its fired position so that the staple driver10580does not sink back down into its staple cavity10530after the sled passes thereby. Such an arrangement allows the staple drivers10580to hold the staples in their deformed shapes thereby reducing spingback of the staples after the staple firing stroke, for example. A staple cartridge11500is illustrated inFIGS.42-44and is similar to the staple cartridges9500and10500in many respects, most of which will not be discussed herein for the sake of brevity. The staple cartridge11500comprises a cartridge body11510including a deck11512, a longitudinal slot11520configured to receive a tissue cutting knife, and longitudinal rows of staple cavities11530defined in the deck11512. The cartridge body11510further comprises longitudinal tissue compression rails11515and11516extending upwardly from the deck11512. The staple cartridge11500further comprises staples removably stored in the staple cavities11530, staple drivers11580configured to support and drive the staples during a staple firing stroke, and a sled configured to sequentially drive the staple drivers11580and the staples from an unfired position to a fired position during the staple firing stroke. The staple cartridge11500also comprises an electrode circuit11590which, although not illustrated, includes electrode contacts on the longitudinal tissue compression rails11515and11516. Further to the above, referring primarily toFIGS.43and44, each staple driver11580comprises a staple seat11581including a slot configured to support a staple, a lateral support11589, and a drive cam11585connecting the staple seat11581and lateral support11589. Notably, the lateral support11589of each staple driver11580is positioned laterally inwardly with respect to the staple seat11581and is closely received within a support cavity defined in the cartridge body11510. The support cavities on one side of the staple cartridge11500comprise openings11519defined in the longitudinal tissue compression rail11516which are sized and configured to permit the lateral supports11589of the drivers11580to protrude upwardly from the cartridge body11510when the staple drivers11580are lifted into their unfired positions. Such an arrangement allows the lateral supports11589to provide additional anti-roll stability to the staple drivers11580. In addition to or in lieu of the above, the longitudinal tissue compression rail11515can comprise openings11519which are configured to receive the lateral supports11589of the other row of staple drivers11580. Also, notably, the lateral support11589extends proximally relative to the staple seat11581. Such an arrangement also provides anti-roll stability to the staple drivers11580. In various alternative embodiments, the lateral supports11589extend distally relative to the staple seats11581. Similar to the above, each staple driver11580comprises a latch arm11588which releasably secures the staple driver11580in its unfired and fired positions and provides additional stability support in those positions. A staple cartridge12500is illustrated inFIGS.45-48Band is similar to the staple cartridges9500,10500, and11500in many respects, most of which will not be discussed herein for the sake of brevity. The staple cartridge12500comprises a cartridge body12510including a longitudinal slot12520defined therein which is configured to receive a tissue cutting knife. The cartridge body12510also includes a longitudinal row of staple cavities12530defined on each side of the longitudinal slot12520. The staple cartridge12500further comprises staples removably stored in the staple cavities12530, longitudinal rows of staple drivers12580configured to support and drive the staples, a sled12550moveable from a proximal unfired position (FIG.45) to a distal fired position to engage and drive the staple drivers12580during a staple firing stroke, and a pan12505that is attached to and extends at least partially under the cartridge body12510. The pan12505prevents, or at least inhibits, the staple drivers12580from being accidentally dislodged from their unfired positions and/or falling out of the bottom of the cartridge body12510until the staple cartridge12500is seated in a surgical instrument12000(FIG.48A), for example. Further to the above, referring primarily toFIGS.46-48, each staple driver12580comprises a staple seat12581, two lateral supports12589, and a drive cam12585. One of the lateral supports12589is laterally-aligned with the staple seat12581and the other lateral support12589is positioned proximally with respect to the staple seat12581. Each staple driver12580further comprises staple supports12582which limit the movement of the staple supported thereon. The staple supports12582have a sufficient height to control the movement of the staple and prevent the staple from sliding laterally off of the staple seat12581. In at least one embodiment, the staple supports12582extend above the base of the staple positioned in the staple seat12581. Notably, the staple supports12582have open longitudinal ends. That said, the longitudinal movement of the staples within the staple cavities12530can be constrained by the longitudinal ends of the staple cavities12530. In any event, referring toFIG.48, the overall height of the staple seat12581is defined between the top of the staple supports12582and a bottom surface12583. As illustrated inFIG.48, the overall height of the lateral supports12589is taller than the overall height of the staple seat12581. Moreover, the lateral supports12589extend vertically above the staple seat12581. Also, the lateral supports12589extend vertically below the staple seat12581. Such an arrangement stabilizes the staple seat12581during the staple forming process. Notably, referring toFIG.48B, the pan12505comprises clearance openings12509defined therein for the lateral supports12589when the staple drivers12580are in their unfired position. A staple cartridge13500is illustrated inFIGS.49and50and is similar to the staple cartridges9500,10500,11500, and12500in many respects, most of which will not be discussed herein out of the sake of brevity. The staple cartridge13500comprises a cartridge body13510including a longitudinal slot13520configured to receive a tissue cutting knife. The cartridge body13510further comprises longitudinal rows of staple cavities13530defined therein. The staple cartridge13500further comprises staples removably stored in the staple cavities13530and longitudinal rows of staple drivers13580configured to support and drive the staples from an unfired position to a fired position during a staple firing stroke. Each staple driver13580comprises a staple seat13581, two lateral supports13589positioned laterally with respect to the staple seat13581, and a drive cam13585positioned between the staple seat13581and the lateral supports13589. The staple seat13581further comprises staple supports13582which define a groove configured to receive the base of a staple and enclosed longitudinal ends13586which co-operatively limit the lateral and longitudinal movement of the staple relative to the staple driver13580. Further to the above, each staple driver13580comprises a guide slot13584defined in the staple seat13581which is slideably engaged with a guide rail13514defined in the cartridge body13510. The guide rails13514and the guide slots13584comprise co-operating features which permit the staple drivers13580to move upwardly within the staple cavities13530but prevent, or at least limit, lateral translation, longitudinal translation, and/or rotation of the staple drivers13580within the staple cavities13530. In various instances, the guide rails13514are closely received within guide slots13584to prevent, or limit, such relative movement. In at least one such embodiment, the guide rails13514and the guide slots13584comprise a dovetail arrangement, for example. Further to the above, the staple cartridge13500further comprises electrode contacts positioned on longitudinal rails13515extending upwardly from the upper surface, or deck, of the cartridge body13510. During use, the current flows from and/or trough the electrode contacts and into the patient tissue to heat, cauterize, and/or seal the patient tissue. In some instances, the patient tissue may stick to the electrode contacts. The cartridge body13510further comprises longitudinal rows of openings13519defined therein which are configured to permit the lateral supports13589to extend above the cartridge body13510when the staple drivers13580are in their fired positions. In such instances, the lateral supports13589can lift the cauterized tissue away from the electrode contacts and free the patient tissue from the staple cartridge13500. In such instances, the patient tissue is at least partially cauterized before the tissue is incised and lifted away from the cartridge body13510during the staple firing stroke. A staple driver14580is illustrated inFIGS.51and52. The staple driver14580comprises two staple seats14581, a lateral support14589, and a driver cam14585which connects the staple seats14581and the lateral support14589together. One of the staple seats14581is positioned in a first staple cavity defined in a staple cartridge and the other staple seat14581is positioned in a second staple cavity defined in a staple cartridge. The staple seats14581are aligned longitudinally with one another and aligned longitudinally with other staple seats14581of other staple drivers14580in the staple cartridge. Each staple seat14581comprises a groove configured to support the base of a staple and staple supports14582configured to limit the relative movement of the staple base relative to the staple seat14581. Moreover, each staple seat14581comprises guide end rails14586which extend into corresponding guide slots defined in the staple cavities which co-operatively prevent, or at least limit, lateral translation, longitudinal translation, and rotation of the staple seats14581within their staple cavities. Further to the above, each staple seat14581comprises a latch14588configured to releasably hold the staple driver14580in its unfired position and/or fired position. A staple cartridge15500is illustrated inFIGS.53and54and is similar to the other staple cartridges disclosed herein in many respects, most of which will not be discussed herein for the sake of brevity. The staple cartridge15500comprises a cartridge body15510including a deck, a longitudinal slot15520defined therein which is configured to receive a tissue cutting knife, and, also, a longitudinal row of staple cavities15530defined on each side of the longitudinal slot15520. The cartridge body15510further comprises a deck and longitudinal tissue compression rails15515extending upwardly from the deck. Further to the above, one or both of the tissue compression rails15515is configured to support and/or house one or more electrodes. As discussed in greater detail further below, the cartridge body15510further comprises pocket extenders15537extending upwardly from the deck. When patient tissue is clamped against the staple cartridge15500, the pocket extenders15537atraumatically grip the patient tissue and prevent, or at least inhibit, the patient tissue from sliding relative to the staple cartridge15500. Further to the above, the staple cartridge15500further comprises staples15540stored in the staple cavities15530, staple drivers15580configured to support and drive the staples15540, and a sled15550configured to sequentially engage the staple drivers15580during a staple firing stroke. Similar to the above, each staple15540comprises a base and legs15542extending from the base. Each staple driver15580comprises a seat configured to receive and support the base of a staple15540positioned in a staple cavity15530. Each staple driver15580further comprises lateral supports15589which provide stability to the seat and a guide slot15584defined in the seat which co-operates with a vertical guide rail15534defined in the staple cavity15530to control the movement of the staple driver15580. The sled15550comprises a central portion15554positioned in the longitudinal slot15520and projections15552extending from the opposite sides of the central portion15554which are configured to engage the sidewalls of the longitudinal slot15520. The interaction between the projections15552and the sidewalls of the longitudinal slot15520inhibits the sled15550from being accidentally moved distally prior to the staple firing stroke but permits the sled15550to be moved distally by the firing drive of a surgical instrument during the staple firing stroke. When the sled15550is not being pushed distally by the firing drive, the sled15550is held in position. The sled15550further comprises two ramps15555—one on each side of the central portion15554—which are each configured to engage and drive a longitudinal row of staple drivers15580. A staple driver21580and a staple21540of a staple cartridge are illustrated inFIGS.72-74. The staple21540is comprised of wire and includes a base21541and legs21542extending upwardly from the base21541. The staple21540is depicted in its unfired configuration inFIG.72and is substantially V-shaped, for example. In at least one embodiment, the legs21542of the staple21540are engaged with the longitudinal ends of a staple cavity which resiliently bias the legs21542inwardly when the staple21540is positioned in the staple cavity. When the staple21540is moved from its unfired position to its fired position by the staple driver21540, the legs21542emerge from the staple cavity and contact the anvil forming pockets positioned opposite the staple cavity. In some instances, the legs21542begin to splay outwardly as the staple21540is lifted upwardly into is fired position. The pocket extenders15537(FIG.53) mentioned above in connection with the staple cartridge15500can limit the outward splay of the staple legs21542and assist in maintaining the alignment between the staple legs21542and the anvil forming pockets. Further to the above, the staple driver21580comprises a staple seat21581including a groove defined therein which supports the base21541of the staple21540and enclosed ends21582which co-operatively prevent, or at least limit, the lateral translation and/or longitudinal translation of the staple base21541relative to the staple seat21581. Notably, the enclosed ends21582of the staple seat21581extend above the base21541of the staple21540when the staple21540is positioned in the staple seat21581. The staple driver21580further comprises a drive cam21585positioned laterally inwardly with respect to the staple seat21581and a stability support21589extending from the drive cam21585. As the staple21540is pushed upwardly into its fired position by the staple driver21580, the enclosed ends21582of the staple driver21580and the pocket extenders15537of the cartridge body15510co-operatively support the staple legs21582as the staple21580is being deformed into its formed configuration. A staple cartridge16500is illustrated inFIGS.55-60and is similar to the other staple cartridges disclosed herein in many respects, most of which will not be discussed herein out of the sake of brevity. The staple cartridge16500comprises a cartridge body16510including a deck16512, a longitudinal slot16520defined therein which is configured to receive a tissue cutting knife, and a longitudinal row of staple cavities16530defined on each side of the longitudinal slot16520. The cartridge body16510further comprises longitudinal tissue compression rails16515extending upwardly from the deck16512where one or both of the tissue compression rails16515is configured to support and/or house one or more electrodes. The cartridge body16510further comprises pocket extenders16537extending upwardly from the deck16512. When patient tissue is clamped against the staple cartridge16500, the pocket extenders16537atraumatically grip the patient tissue and prevent, or at least inhibit, the patient tissue from sliding relative to the staple cartridge16500. Further to the above, the staple cartridge16500further comprises staples stored in the staple cavities16530, staple drivers16580configured to support and drive the staples16540, and a sled configured to sequentially engage the staple drivers16580during a staple firing stroke. Referring primarily toFIG.58, each staple driver16580comprises a staple seat16581, lateral supports16589, and a drive cam connecting the lateral supports16589. Each staple cavity16530comprises a lateral support cavity16539within which the lateral supports16589are closely received to resist unwanted lateral and longitudinal translation and/or unwanted rotation of the staple driver16580. Notably, referring primarily toFIGS.59and60, the top of the lateral support cavities16539are enclosed and provide an upward stop for the staple drivers16580during the staple firing stroke. In addition, referring toFIGS.57and58, each staple driver16580further comprises a latch, or lock arm,16588which releasably engages a sidewall of a lock window16517defined in the cartridge body16510to releasably hold the staple driver16580in its unfired position (FIG.59) until the staple driver16580is driven upwardly by the sled. The lock arm16588comprises a cantilever which flexes inwardly when the staple driver16580is lifted upwardly by the sled and then resiliently flexes outwardly when the staple driver16580reaches its fired position (FIG.60). In such instances, the lock arm16588engages the deck16512and holds the staple driver16580in its fired position. A staple cartridge17500is illustrated inFIGS.61-63, and is similar to the other staple cartridges disclosed herein in many respects, most of which will not be discussed herein out of the sake of brevity. The staple cartridge17500comprises a cartridge body17510including a deck17512, a longitudinal slot17520defined therein which is configured to receive a tissue cutting knife, and a longitudinal row of staple cavities17530defined on each side of the longitudinal slot17520. The cartridge body17510further comprises longitudinal tissue compression rails17515extending upwardly from the deck17512where one or both of the tissue compression rails17515is configured to support and/or house one or more electrodes. The cartridge body17510further comprises pocket extenders17537extending upwardly from the deck17512. When patient tissue is clamped against the staple cartridge17500, the pocket extenders17537atraumatically grip the patient tissue and prevent, or at least inhibit, the patient tissue from sliding relative to the staple cartridge17500. Further to the above, the staple cartridge17500further comprises staples stored in the staple cavities17530, staple drivers17580configured to support and drive the staples, and a sled configured to sequentially engage the staple drivers17580during a staple firing stroke. Referring primarily toFIG.63, each staple driver17580comprises a staple seat17581which defines a groove configured to receive the base of a staple, staple supports17582extending to the lateral sides of the groove, lateral supports17589, and a drive cam17585connecting the lateral supports17589to the staple seat17581. Each staple cavity17530comprises a lateral support cavity within which the lateral supports17589are closely received to resist unwanted lateral and longitudinal translation and/or unwanted rotation of the staple driver17580. Notably, the lateral supports17589of each staple driver17580define a guide slot17584therebetween which closely receives a guide rail17534defined in a staple cavity17530. The guide slot17584and guide rail17534co-operatively constrain the movement of the staple driver17580to vertical movement within the staple cavity17530. Also, notably, the lateral supports17589are positioned laterally outwardly with respect to the staple seat17581and do not extend under the longitudinal tissue compression rails17515. In addition, each staple driver17580further comprises a latch, or lock arm,17588which is releasably engaged with a sidewall of an internal lock window defined in the cartridge body17510to releasably hold the staple driver17580in its unfired position until the staple driver17580is driven upwardly by the sled. The lock arm17588comprises a cantilever which flexes inwardly when the staple driver17580is lifted upwardly by the sled and then resiliently flexes outwardly when the staple driver17580reaches its fired position. In such instances, the lock arm17588engages the deck17512and holds the staple driver17580in its fired position. A lock shoulder of the lock arm17588faces outwardly toward the lateral supports17589but could extend in any suitable direction. A staple cartridge18500is illustrated inFIGS.64and65and is similar to the other staple cartridges disclosed herein in many respects, most of which are not discussed herein for the sake of brevity. The staple cartridge18500comprises a cartridge body18510including a longitudinal slot18520configured to receive a tissue cutting knife and a longitudinal row of staple cavities18530defined on each side of the longitudinal slot18520. The cartridge body18510further comprises an upper portion, or deck,18512and longitudinal tissue compression rails18515and18516extending upwardly from the deck18512. The staple cartridge18500further comprises a staple18540positioned in each staple cavity18530, staple drivers18580configured to support and drive the staples18540during a staple firing stroke, and a sled configured to contact and drive the staple drivers18580. The staple cartridge18500further comprises an electrode circuit18590including electrode contacts18594housed within the longitudinal tissue compression rail18516and a conductor18596electrically connecting the electrode contacts18594. As illustrated inFIG.64, each electrode contact18594extends longitudinally and the electrode contacts18594collectively extend along a substantial majority of the longitudinal tissue compression rail18516. In at least one embodiment, the electrode contacts18594extend along at least 90% of the longitudinal length of the tissue compression rail18516, for example. In at least one embodiment, the electrode contacts18594cover at least 95% of the longitudinal length of the tissue compression rail18516, for example. A staple cartridge19500is illustrated inFIGS.66-69and is similar to the other staple cartridges disclosed herein in many respects, most of which will not be discussed herein out of the sake of brevity. The staple cartridge19500comprises a cartridge body19510including a deck, a longitudinal slot19520configured to receive the firing member1570(FIG.69) of the firing drive1600, and longitudinal rows of staple cavities19530. The staple cartridge19500further comprises a staple19540positioned in each staple cavity19530, staple drivers19580configured to support and drive the staples19540during a staple firing stroke, and a sled19550configured to sequentially contact and push the staple drivers19580and19540upwardly within the staple cavities19530during the staple firing stroke. Referring primarily toFIG.67, the sled19550comprises a central portion19554which slides within the longitudinal slot19520, and lateral ramps19555which slide within longitudinal ramp slots defined in the cartridge body19510and engage the staple drivers19580. When the staple cartridge19500is seated in the cartridge jaw1310, referring primarily toFIG.69, the sled19550is positioned over, but not operably engaged with, the drive screw1560. Notably, the drive screw1560is closely received within a clearance slot19553defined in the bottom of the sled19550such that there is little gap between the drive screw1560and the sled19550. During the staple firing stroke, the drive screw1560is rotated to drive the firing member1570distally which pushes the sled19550distally. Further to the above, the firing member1570is configured to pull the anvil jaw toward the staple cartridge19500during the staple firing stroke. In many instances, as a result, the staple cartridge19500can experience a significant compressive load—especially around the staples19540being deformed against the anvil jaw. Notably, the sled19550is positioned directly under the staple drivers19580being lifted by the sled19550and can support the cartridge body19510if it deflects downwardly as a result of the compressive load. Referring again toFIGS.66and67, the sled19550comprises angled support shoulders19551defined on opposite sides thereof. The angled support shoulders19551of the sled19550are directly adjacent to and/or are in abutting contact with angled shoulders19511defined in the cartridge body19510which extend along the longitudinal length thereof. As a result, the cartridge body19510can be directly supported by the sled19550and limit the deflection of the cartridge body19510during the staple firing stroke. In some instances, the sled19550can be pushed downwardly against the drive screw1560by the cartridge body19510. As such, the surface of the clearance aperture19553in the sled19550is smooth such that the sled19550can slide over and relative to the drive screw1560even though the drive screw1560is rotating. Further to the above, each staple driver19580comprises a lateral stability support19589configured to slide within a support slot19539defined in the cartridge body19510. Each staple driver19580further comprises a clearance recess19583defined therein which is configured to closely receive the drive screw1560when the staple drivers19580are in their unfired positions. Such an arrangement allows for a staple cartridge19500that is vertically compact. A staple cartridge20500is illustrated inFIGS.70and71. The staple cartridge20500comprises a cartridge body20510comprising staple cavities, a pan20505attached to the cartridge body20510, staples removably stored in the staple cavities, and staple drivers. The pan20505comprises a plurality of latches and/or lock windows engaged with features defined on the cartridge body20510which secure the pan20505to the cartridge body20510. Further to the above, the pan20505at least partially extends under the cartridge body20510and prevents, or at least inhibits, the staple drivers and staples stored within the cartridge body20510from being accidentally dislodged from their unfired positions when the staple cartridge20500is loaded into a cartridge jaw. Further to the above, the cartridge body20510further comprises supports20501embedded therein. In at least one embodiment, the cartridge body20510is comprised of a plastic material which is injection molded around the supports20501such that the supports20501are integrally-formed with the cartridge body20510. Referring toFIG.71, each support20501comprises an upper portion20502embedded in the deck of the cartridge body20510and a lower portion20503which extends out of the bottom of the cartridge body20510. When the pan20505is assembled to the cartridge body20510, the lower portions20503of the supports20501are engaged with and/or directly adjacent to the pan20505. When a compression load is applied to the staple cartridge20500as a result of the end effector being closed, further to the above, the supports20501resist the downward deflection of the cartridge body20510by transmitting at least a portion of the compression load into the pan20505. During the staple firing stroke, in at least one embodiment, the supports20501yield, or give way, under the compressive load and/or as the result of the sled contacting the supports20501and bending them out of contact with the pan20505. As a result of the above, the staple cartridge20500is able to resist the compressive loading during use but is not re-usable. A staple cartridge22500is illustrated inFIGS.75-79and is similar to other staple cartridge disclosed herein in many respects, most of which will not be discussed herein for the sake of brevity. The staple cartridge22500comprises a cartridge body22510including staple cavities22530defined therein, a staple positioned in each staple cavity22530, staple drivers22580configured to drive the staples upwardly within the staple cavities22530, and a sled22550movable from a proximal unfired position (FIG.77) to a distal fired position (FIG.79) to engage the staple drivers22580during a staple firing stroke. Referring primarily toFIGS.75and76, the sled22550comprises lateral angled drive plane surfaces22555configured to engage and lift the staple drivers22580during the staple firing stroke. Each angled drive plane surface22555extends from the distal, or wedge tip, end of the sled22550to the proximal, apex, end of the sled22550. Each staple driver22580comprises a corresponding angled cam plane surface which slides upwardly on one of the angled drive plane surfaces22555as the sled22550slides under the staple drivers22850. Each staple driver22850comprises a guide key22859extending therefrom which is slideably received in a key slot defined in the cartridge body22510which constrains the motion of the staple drivers22850to vertical movement within the cartridge body22510. FIGS.80-85illustrate a drive system23000for use with a surgical instrument, such as those described herein. The drive system23000comprises a shift motor23100, a drive motor23300, and a lock bar, or brake,23400. Referring primarily toFIG.81, the shift motor23100comprises a rotary output shaft23110including an external thread portion23120. The shift motor23100may be a stepper motor or any suitable motor configured to actuate the rotary output shaft23110between a plurality of set rotated positions. The threaded portion23120is threadably engaged with a motor carrier23200. Specifically, internal threads of the motor carrier23200are threadably engaged with the external thread portion23120of the rotary output shaft23110. As such, when the rotary output shaft23110is rotated in a first direction, the motor carrier23200is translated distally. Notably, the motor carrier23200does not rotate with the rotary output shaft23110. Correspondingly, when the rotary output shaft23110is rotated in a second direction opposite the first direction, the motor carrier23200is translated proximally. Further to the above, the motor carrier23200comprises an opening23220configured to receive the drive motor23300. The drive motor23300is fixed and/or attached to the motor carrier23200such that the drive motor23300translates with the motor carrier23200. Any suitable method may be utilized to affix the drive motor23300within the opening23220of the motor carrier23200such as welding, and/or adhesives, and/or fasteners, for example. Other embodiments are envisioned where the drive motor23300is press fit into the opening23220of the motor carrier23200. Further, other embodiments are envisioned where the motor carrier23200and the drive motor23300are one unitary component. In any event, the motor carrier23200and the drive motor23300translate together between a plurality of positions in response to the actuation of the rotary output shaft23110of the shift motor23100between a plurality of radial positions. Further to the above, the drive motor23300comprises a rotary output shaft, or drive motor shaft23310. The drive motor shaft23310extends distally from a body portion23305of the drive motor23300. The drive motor shaft23310comprises a proximal radial groove23320and a distal radial groove23330spaced apart from one another along the drive motor shaft23310. The radial grooves23320,23330define narrower shaft portions compared to the remainder of the drive motor shaft23310. Further, the drive system23000comprises a main drive gear23340fixed to the drive motor shaft23310intermediate the proximal radial groove23320and the distal radial groove23330. The main drive gear23340may be fixed to the drive motor shaft23310using any suitable means such as welding, and/or fasteners, and/or adhesives, for example. Other embodiments are envisioned where the main drive gear23340is press fit onto the drive motor shaft23310, for example. In any event, rotation of the drive motor shaft23310via the drive motor23300will result in the rotation of the main drive gear23340. Further, the main drive gear23340is configured to rotate one of a plurality of output drive gears and their respective output shafts depending upon the longitudinal position of the drive motor23300, as discussed in greater detail below. Further to the above, the drive system23000further comprises a lock bar, or brake23400, a first output gear23500, a second output gear23600, and a third output gear23700. Referring primarily toFIG.81, the brake23400comprises a body portion23405including a clevis portion23407extending laterally from the body portion23405. The clevis portions23407comprises a proximal collar23410and a distal collar23420spaced apart from one another. The proximal collar23410is configured to be received around the proximal radial groove23320, and the distal collar23420is configured to be received around the distal radial groove23330. Specifically, the proximal collar23410comprises a proximal opening23412which receives the drive motor shaft23310in the region of the proximal radial groove23320. Further, the distal collar23420comprises a distal opening23422which receives the drive motor shaft23310in the region of the distal recess23330. Further, the brake23400is free to rotate about the drive motor shaft23310. As such, the brake23400, the drive motor23300, and the drive motor shaft23310translate together when the shift motor23100is actuated; however, the brake23400does not rotate with the drive shaft23310. Other embodiments are envisioned where the brake23400is operably attached to the handle or housing of the instrument such that the brake23400translates with the drive motor23300without the brake23400being attached to the drive motor shaft23310. In any event, the brake23400translates with the drive motor shaft23310to selectively engage two of the three output gears23500,23600, and23700to prevent their rotation while permitting one of the three output gears23500,23600, and23700to rotate, as discussed in greater detail below. Referring primarily toFIG.81, the first output gear23500comprises a first output shaft23510extending distally therefrom, the second output gear23600comprises a second output shaft23610extending distally therefrom, and the third output gear23700comprises a third output shaft23710extending distally therefrom. The output drive shafts23510,23610,23710are rotatably supported within the handle or housing of the instrument and are configured to effectuate different motions within an end effector or stapling attachment of a surgical instrument. Further, the output drive shafts23510,23610,23710are nested within one another. Specifically, the first output drive shaft23510is received within an opening23620in the second output drive shaft23610, and the first and second output drive shafts23510,23610are received within an opening23720in the third output drive shaft23710. As such, the output drive shafts23510,23610,23710are rotatable relative to one another about the same longitudinal axis. Referring primarily toFIG.82, the brake23400comprises a pair of longitudinal teeth23430extending laterally from the body portion23405. The pair of longitudinal teeth23430extend longitudinally along the entire body portion23405except for a gap23440defined in the pair of longitudinal teeth23430. Specifically,FIGS.83-85illustrate the gap23440in the pair of longitudinal teeth23430. The longitudinal teeth23430are configured to meshingly engage with teeth of the output gears23500,23600,23700to selectively prevent their rotation depending upon the longitudinal position of the brake23400. Specifically, the longitudinal position of the brake23400, which is translatable by the shift motor23100, determines which of the output gears23500,23600,23700can be freely rotated, as discussed in greater detail below. In use, when the shift motor23100positions the drive motor23300and brake23400in a first position, as illustrated inFIG.83, teeth on the main drive gear23340are meshingly engaged with teeth on the first output gear23500. As such, rotation of the main drive gear23340will rotate the first output gear23500and the first output drive shaft23510to perform a first end effector function. Further, the gap23440of the brake23400is positioned such that the pair of longitudinal teeth23430of the brake23400are only engaged with the second output gear23600and the third output gear23700and, thus, the second output gear23600and the third output gear23700are prevented from rotating—thereby locking out a second end effector function and a third end effector function. In various embodiments, the first end effector function comprises the articulation of the end effector, for example. In at least one such embodiment, the end effector of the surgical instrument is rotatable about an articulation joint. In at least one embodiment, the second end effector function comprises rotating the end effector about a longitudinal axis, for example. In at least one such embodiment, the surgical instrument comprises a rotation joint proximal to the articulation joint which permits at least a portion of the shaft and the end effector of the surgical instrument to rotate about the longitudinal axis. In at least one embodiment, the surgical instrument comprises a rotation joint distal to the articulation joint which permits the end effector to rotate relative to the shaft about a longitudinal axis. In at least one embodiment, the third end effector function comprises advancing a tissue cutting knife distally through the end effector, for example. Further to the above, when the shift motor23100positions the drive motor23300and the brake23400in a second position, as illustrated inFIG.84, the teeth of the main drive gear23340are meshingly engaged with the teeth of the second output gear23600. As such, rotation of the main drive gear23340will rotate the second output gear23600and the second output drive shaft23610. Further, the gap23440of the brake23400is positioned such that the pair of longitudinal teeth23430of the brake23400are only engaged with the first output gear23500and the third output gear23700—and not the second output gear23600—and, thus, the first output gear23500and the third output gear23700are prevented from rotating. Further to the above, when the shift motor23100positions the drive motor23300and the brake23400in a third position, as illustrated inFIG.85, the teeth of the main drive gear23340are meshingly engaged with teeth of the third output gear23700. As such, rotation of the main drive gear23340will rotate the third output gear23700and the third output drive shaft23710. Further, the gap23440of the brake23400is positioned such that the pair of longitudinal teeth23430of the brake23400are only engaged with the first output gear23500and the second output gear23600—and not the third output gear23700—and, thus, the first output gear23500and the second output gear23600are prevented from rotating. FIGS.86-92illustrate a drive system24000for use with a surgical instrument, such as those described herein. The drive system24000comprises a drive motor24100and a shift motor24200. Referring primarily toFIG.89, the drive motor24100comprises a rotary input shaft24110and a drive motor gear24120mounted onto the rotary input shaft24110. The drive motor gear24120is operably engaged with a first idler gear24130, a second idler gear24140, and a third idler gear24150. Specifically, the teeth of the drive motor gear24120are meshingly engaged with only the teeth of the first idler gear24130while the teeth of the first idler gear24130are meshingly engaged with the teeth of the second idler gear24140and the teeth of the third idler gear24150. The second idler gear24140and the third idler gear24150are positioned on opposite sides of the first idler gear24130. As such, rotation of the drive motor gear24120via the drive motor24100results in simultaneous rotation of the first idler gear24130, the second idler gear24140, and the third idler gear24150. The above being said, other embodiments are envisioned where the drive motor gear24120is positioned in between all three idler gears24130,24140,24150and meshingly engaged with all three idler gears24130,24140,24150. Referring primarily toFIG.88, the first idler gear24130is mounted to a first rotary input shaft24132, the second idler gear24140is mounted to a second rotary input shaft24142, and the third idler gear24150is mounted to a third rotary input shaft24152. In the illustrated embodiment, the drive motor gear24120and the idler gears24130,24140,24150are attached to their respective shafts24132,24142,24152via a pin, or screw. However, other embodiments are envisioned where the drive motor gear24120and the idler gears24130,24140,24150are fixed and/or attached to their respective shafts24132,24142,24152using any suitable means such as welding, adhesives, press fitting, etc., for example. In any event, the first rotary input shaft24132comprises a first input clutch24134extending from its distal end, the second rotary input shaft24142comprises a second input clutch24144extending from its distal end, and the third rotary input shaft24152comprises a third input clutch24154extending from its distal end. The input clutches24134,24144,24154are configured to be selectively engageable with three different output clutches, as discussed in greater detail below. Referring primarily toFIG.88, the shift motor24200comprises a shift motor shaft24210comprising a rotary index shaft24220. The rotary index shaft24220defines a longitudinal axis LA and is configured to rotate about its longitudinal axis LA when the shift motor24200is actuated. The shift motor24200may be a stepper motor or any suitable motor configured to actuate the rotary index shaft24220between a plurality of set rotated positions, for example. Further, the rotary index shaft24220comprises three separate cam profiles24222,24224,24226extending all the way around the rotary index shaft24220, as discussed in greater detail below. Further to the above, the rotary index shaft24220comprises a first cam profile24222, a second cam profile24224, and a third cam profile24226. Each of the first, second, and third cam profiles24222,24224,24226define a radial groove in the rotary index shaft24220. Further, each cam profile24222,24224,24226is different when viewed in reference to the longitudinal axis LA. Specifically, the first cam profile24222is identical to the second cam profile24224; however, the second cam profile24224is rotated approximately 60 degrees relative to the first cam profile24222about the longitudinal axis LA. Further, the second cam profile24224is identical to the third cam profile24226; however, the third cam profile is rotated approximately 60 degrees relative to the second cam profile24225. It shall be understood that any suitable orientation of the cam profiles24222,24224,24226relative to one another are contemplated. As discussed in greater detail below, each of the cam profiles24222,24224,24226are distinctly defined in the rotary index shaft24220relative to the longitudinal axis LA to effectuate different movements of three separate cams. Referring primarily toFIG.88, a first cam24300comprises an opening24310configured to receive the rotary index shaft24220. The first cam24300comprises a first cam pin24320(seeFIG.87) extending through the opening24310and into the first cam profile24222such that the first cam pin24320rides within and along the first cam profile24222when the rotary index shaft24220is rotated. Further, a second cam24400comprises an opening24410configured to receive the rotary index shaft24220. The second cam24400comprises a second cam pin24420(seeFIG.87) extending through the opening24410and into the second cam profile24224such that the second cam pin24420rides within and along the second cam profile24224when the rotary index shaft24220is rotated. Further, a third cam24500comprises an opening24510configured to receive the rotary index shaft24220. The third cam24500comprises a third cam pin24520extending through the opening24510and into the third cam profile24226such that the third cam pin24520rides within and along the third cam profile24226when the rotary index shaft24220is rotated. As discussed in greater detail below, each of the cams24300,24400,24500can translate longitudinally relative to the longitudinal axis LA when the rotary index shaft24220is rotated about the longitudinal axis LA. Referring primarily toFIG.88, the first cam24300comprises a first lateral flange24330and a first opening24340defined in the first lateral flange24330. The second cam24400comprises a second lateral flange24430and a second opening24440defined in the second lateral flange24430. The third cam24500comprises a third lateral flange24530and a third opening24540defined in the third lateral flange24530. A first rotary output shaft24600extends through the first opening24340, a second rotary output shaft24700extends through the second opening24440, and a third rotary output shaft24800extends through the third opening24540, as discussed in greater detail below. Further to the above, the first rotary output shaft24600, the second rotary output shaft24700, and the third rotary output shaft24800are rotatably mounted to the surgical instrument. The output shafts24600,24700,24800are rotatably supported within the instrument by thrust bearings, for example, and/or any other suitable means. A first output clutch24610is slideably mounted on the proximal end of the first rotary output shaft24600. The first output clutch24610comprises a protrusion, or key,24630positioned in a groove24640defined in the first output shaft24600. The protrusion and groove arrangement24630,24640permits the first output clutch24610to slide, or translate, relative to the first output shaft24600and also rotate with the first output shaft24600. Further, a second output clutch24710is slideably mounted on the proximal end of the second rotary output shaft24700. The second output clutch24710comprises a protrusion, or key,24730positioned in a groove24740defined in the second output shaft24700. The protrusion and groove arrangement24730,24740permits the second output clutch24710to slide, or translate, relative to the second output shaft24700and also rotate with the second output shaft24700. Further, a third output clutch24810is slideably mounted on the proximal end of the third rotary output shaft24800. The third output clutch24810comprises a protrusion, or key,24830positioned in a groove24840in the third output shaft24800. The protrusion and groove arrangement24830,24840permits the third output clutch24810to slide, or translate, relative to the third output shaft24800and also rotate with the third output shaft24800. Referring primarily toFIG.88, the first output clutch24610comprises a first radial groove24620that is received in—and rotatable within—the first opening24340of the first cam24300. The second output clutch24710comprises a second radial groove24720that is received in—and rotatable within—the second opening24440of the second cam24400. The third output clutch24810comprises a third radial groove24820that is received in—and rotatable within—the third opening24540of the third cam24500. As such, the first output clutch24610is rotatable relative to the first cam24300, the second output clutch24710is rotatable relative to the second cam24400, and the third output clutch24810is rotatable relative to the third cam24500. Further, the sidewalls of the radial grooves24620,24720,24820of the output clutches24610,24710,24810, respectively, provide bearing surfaces for the cam members24300,24400,24500to translate the output clutches24610,24710,24810relative to their respective output shafts24600,24700,24800. As discussed in greater detail below, such translation of the output clutches24610,24710,24810relative to their respective output shafts24600,24700,24800allows the output clutches24610,24710,24810to be selectively engaged with and disengaged from their respective input clutches24134,24144,24154. Referring toFIG.90, the rotary index shaft24220of the shift motor24200is in a first radial position relative to the longitudinal axis LA. The cams24300,24400,24500are in a first configuration when the rotary index shaft24200is in its first radial position. In the first configuration, the first cam24300and the first output clutch24610are in a distal position where the first output clutch24610is not engaged with the first input clutch24134. Further, in the first configuration, the second cam24400and the second output clutch24710are in a proximal position where the second output clutch24710is engaged with the second input clutch24144. Further, in the first configuration, the third cam24500and the third output clutch24810are in a distal position where the third output clutch is not engaged with the third input clutch24154. As such, in the first configuration, only the second output clutch24710is engaged with its respective input clutch24400. Therefore, when the cams24300,24400,24500are in their first configuration (FIG.90), rotation of drive motor gear24120will result in rotation of the second output shaft24700. Referring toFIG.91, the rotary index shaft24220has been rotated into a second radial position about the longitudinal axis LA from the first radial position inFIG.90. The cams24300,24400,24500are in a second configuration when the rotary index shaft24220is in its second radial position. Specifically, the first cam24300and the second cam24400have moved toward one another while the third cam24500remains in the same longitudinal position as in the first configuration ofFIG.90. The first cam24300and the second cam24400are translated toward one another due to the first and second cam profiles24222,24224of the rotary index shaft24220cammingly engaging the first and second cam pins24320,24420of the first and second cams24300,24400when the rotary index shaft24220is rotated from its first radial position to its second radial position. A dwell of the third cam profile24226is radially oriented relative to the first and second cam profiles24222,24224such that the third cam pin24520is not translated when the rotary index shaft24200rotates from its first radial position to its second radial position. As such, the third cam24500and the third output clutch24810do not translate when the rotary index shaft24220rotates from its first radial position to its second radial position. Further to the above, when the cams24300,24400,24500are in the second configuration as illustrated inFIG.91, the first cam24300and the first output clutch24610are in a proximal position where the first output clutch24610is engaged with the first input clutch24134. Further, in the second configuration, the second cam24400and the second output clutch24710are in a distal position where the second output clutch24710is not engaged with the second input clutch24144. Further, in the second configuration, the third cam24500and the third output clutch24810remain in their distal position where the third output clutch24810is not engaged with the third input clutch24154. As such, in the second configuration, only the first output clutch24610is engaged with its respective input clutch24134. Therefore, when the cams24300,24400,24500are in their second configuration (FIG.91), rotation of drive motor gear24120will result in rotation of first output shaft24600. Referring toFIG.92, the rotary index shaft24220has been rotated into a third radial position about the longitudinal axis LA from its second radial position inFIG.91. The cams24300,24400,24500are in a third configuration when the rotary index shaft24220is in its third radial position. Specifically, the first cam24300and the third cam24500move away from one another while the second cam24400remains in the same longitudinal position as the second configuration (FIG.91). The first cam24300and the third cam24500are translated away from one another due the first and third cam profiles24222,24226of the rotary index shaft24222cammingly engaging the first and third cam pins cam pins24320,24520of the first and third cams24300,24500when the rotary index shaft24220is rotated from its second radial position to its third radial position. A dwell of the second cam profile24224is radially oriented relative to the first and third cam profiles24222,24226such that the second cam pin24420is not translated when the rotary index shaft24200rotates from its second radial position to its third radial position. As such, the second cam24400and the second output clutch24710do not translate when the rotary index shaft24220rotates from its second radial position to its third radial position. Further to the above, when the cams24300,24400,24500are in the third configuration as illustrated inFIG.92, the first cam24300and the first output clutch24610are in the distal position where the first output clutch24610is not engaged with the first input clutch24134. Further, in the third configuration, the second cam24400and the second output clutch24710remain in the distal position where the second output clutch24710is not engaged with the second input clutch24144. Further, in the third configuration, the third cam24500and the third output clutch24810are in a proximal position where the third output clutch24810is engaged with the third input clutch24154. As such, in the third configuration, only the third output clutch24810is engaged with its respective input clutch24154. Therefore, when the cams24300,24400,24500are in their third configuration (FIG.92), rotation of drive motor gear24120will result in rotation of third output shaft24800. Referring toFIG.86, the rotary index shaft24220is in a fourth radial position that is different than the first radial position (FIG.90), the second radial position (FIG.91), and the third radial position (FIG.92). When the rotary index shaft24220is in the fourth radial position, the cam members24300,24400,24500are in a fourth configuration. In the fourth configuration, the cams24300,24400,24500and their respective output clutches24610,24710,24810are in their distal positions where the output clutches24610,24710,24810are not engaged with their respective input clutches24134,24144,24154. As such, when the cams24300,24400,24500are in the fourth configuration (FIG.86), rotation of drive motor gear24120will not result in the rotation of any of the output shafts24600,24700,24800. FIGS.93-96depict a surgical instrument assembly25000comprising a shaft25010, an end effector25020, and an articulation joint, or region,25030. The surgical instrument assembly25000further comprises a primary drive shaft25060configured to actuate a function of the end effector25020and articulation actuators25050configured to articulate the end effector25020relative to the shaft25020about pivot axis PA. The shaft25010comprises a distal end25011comprising tabs25012extending from the distal end25011of the shaft25010. The shaft25010further comprises a central cavity25014configured to receive the primary drive shaft25060and articulation actuators25050therethrough. The central cavity25014may also receive other drive shafts, frame components, and/or electrical components therethrough, for example. The end effector25020comprises a proximal end25021comprising tabs25023extending from the proximal end25021of the end effector25020. The tabs25012are pivotally coupled to the tabs25023to pivotally couple the shaft25010and the end effector25020together an enable articulation of the end effector25020relative to the shaft25010. The tabs25012and the tabs25023are pivotally coupled to each other by way of pins25031. The pivot axis PA is defined by the pins25031. The articulation joint25030comprises an articulation support pivot25040. The articulation support pivot25040comprises a cylindrical member positioned within a cavity25022defined between the tabs25012and the tabs25023and is configured to pivot when actuated by articulation actuators25050. While the term ‘cylindrical’ is used, the articulation support pivot need not resemble a perfect cylinder. Each articulation actuator25050comprises a distal end25051. The distal ends25051are pinned to the articulation support pivot25040by way of actuation pin25035. The articulation actuators25050may comprise any suitable type of actuator such as, for example, flexible actuators, cables, flexible plastic plates, electroactive polymer actuators, and/or piezoelectric bimorph actuators. The articulation support pivot25040comprises a central cavity25041defined therethrough along a longitudinal axis LA. The primary drive shaft25060is configured to be received through the central cavity25041. In at least one instance, the primary drive shaft25060is flexible and is configured to bend, or flex, as the end effector25030is articulated relative to the shaft25010. In at least one instance, the primary drive shaft25060comprises a flexible actuator. In at least one instance, the primary drive shaft25060comprises a linearly translatable actuator. In at least on instance, the primary drive shaft25060comprises rotary drive shaft. In at least one instance, the primary drive shaft25060is flexible, is configured to be rotated to actuate a function of the end effector, and is configured to be translated to actuate a function of the end effector25020. In at least one instance, the articulation support pivot comprises a prism structure, a spherical structure, and/or a rectangular structure. To articulate the end effector25020, the articulation actuators25050are configured to be pushed and pulled in an antagonistic manner to articulate the end effector25030relative to the shaft25010. For example, a first actuator25050is configured to push a first side of the pin25035distally and a second actuator25050is configured to pull a second side of the pin25035proximally resulting in the rotation, or pivoting, of the articulation support pivot25040to articulate the end effector25020in a first direction. Similarly, the first actuator25050is configured to pull a first side of the pin25035proximally and the second actuator25050is configured to push a second side of the pin25035distally resulting in the rotation, or pivoting, of the articulation support pivot25040to articulate the end effector25020in a second direction opposite the first direction. In at least one instance, the primary drive shaft25060is bent, or pivoted, by the central cavity25041of the articulation support pivot25040. As a result, the primary drive shaft25060is configured to apply a pivot force to the end effector25020to articulate the end effector25020in the desired direction. In at least one instance, a first articulation actuator25050is actively actuated and passive movement of a second articulation actuator25050is dependent on the actuation of the first actuator25050. In at least one instance, only one articulation actuator25050is provided. In at least one instance, the end effector25020is fixedly attached to the articulation support pivot25040such that, as the articulation support pivot25040is rotated by the actuators25050and actuation pin25035, the articulation support pivot25040directly articulates the end effector25020relative to the shaft25010by virtue of the fixed relationship between the end effector25020and the articulation support pivot25040. In such an instance, the end effector25020may aid in flexing the primary drive shaft25060when the end effector25020is articulated relative to the shaft25010. In at least one instance, the articulation support pivot25040defines a central axis which is transverse to the longitudinal axis LA. In at least one instance, the central axis is aligned with the pivot axis PA. In such an instance, the articulation support pivot25040rotates about the pivot axis PA. In at least one instance, the articulation support pivot25040is configured float laterally within the articulation joint25030. In such an instance, the axis about which the articulation support pivot25040rotates is not fixed relative to the end effector25020and/or the shaft25010and, rather, moves laterally and/or longitudinally relative to the end effector25020and/or the shaft25010. Such a configuration may provide a degree of flexibility within the articulation joint25030by removing a fixed pivot axis and providing a semi-movable, or floatable, pivot axis. As can be seen inFIG.95, the articulation support pivot25040is configured to prevent the primary drive shaft25060from blowing out of the articulation joint25030. The central cavity25041is configured to restrain the primary drive shaft25060within the articulation joint25030as the end effector25020is articulated relative to the shaft25010. In at least one instance, the central cavity25041laterally and vertically supports the primary drive shaft25060through the articulation joint25030. In at least one instance, the articulation pin25035provides a vertical support limit within the central cavity25041. In at least one instance, the articulation support pivot25040is assembled with the shaft25010and end effector25020and then the primary drive shaft25060is inserted through the shaft25010and central cavity25041and into the end effector25020. As a result, the primary drive shaft25060itself is configured to prevent disassembly of the articulation joint25030. In such an instance, the primary drive shaft25060itself holds one or more components of the articulation joint25030together. FIG.97depicts a surgical instrument assembly25100comprising many of the same components of the surgical instrument assembly25000. The surgical instrument assembly25100comprises an articulation joint25130comprising pivot pins25131which, unlike the surgical instrument assembly25100, pin the tabs25012,25023to each other in addition to an articulation support pivot25140. The articulation support pivot25140may comprise the same and/or similar functions of the articulation support pivot25040. The articulation support pivot25140comprises a central cavity25141defined therethrough configured to receive a portion of the pin25035and the primary drive shaft25060. The articulation joint25130may allow for a more distinct pivot by pivotally coupling the shaft25010to the articulation support pivot25140. In at least one instance, the end effector25020is fixedly attached to the articulation support pivot25140. In at least one instance, the end effector25020is pivotally attached to the articulation support pivot25140. FIGS.98and99depict a surgical instrument assembly25200comprising an end effector cartridge25210, a firing member25270, and a plurality of flexible actuators25220. The actuators25220comprise a plurality of first actuators25260and a tube25230. The tube25230may comprise a linearly translatable member configured to push and/or pull the firing member25270. In at least one instance, the tube25230acts only as a jacket to the actuator25260to allow a flex circuit25240to be wrapped therearound. The surgical instrument assembly25200may comprise an articulation joint through which the actuators25220are configured to extend. To this end, each actuator25260comprises a plurality of slits25261configured to allow the actuators25260to flex, or bend, in a first predetermined direction. The direction may correspond to the plane of articulation through which the end effector cartridge25210is articulated. In at least one instance, each actuator25260comprises additional slits to allow the actuators25260to flex, or bend, in a second predetermined direction in addition to the first predetermined direction. Such a configuration would permit the use of the actuators25260in a multi-axis articulation joint where the end effector cartridge25210may be articulated in two distinct planes. In at least one instance, the actuators25260are provided to articulate the end effector cartridge25210by applying an articulation force to the end effector cartridge25210through the firing member25270. The actuators25260may comprise an electroactive polymer and/or a piezoelectric bimorph configured to be energized to bend the actuators25260into a desired bent configuration thereby causing the firing member25270to which the actuators25260are attached to be moved in a predetermined direction. The actuators25260may also be advanced and/or rotated to effect one or more functions of the end effector cartridge25210and/or end effector assembly comprising the end effector cartridge25210. For example, the actuators25260may be translated linearly to push the firing member25270distally and/or pull the firing member25270proximally. In at least one instance, the actuators25260are configured to apply a rotational force to the firing member25270to rotate the end effector cartridge25210relative to a shaft, for example. In such an instance, the actuators25260may be actuated by a planetary gear train, for example. The slits25260may be formed in the actuators25260by way of any suitable method. For example, the slits25260may be laser cut into the actuators25260. The actuators25260may comprise of any suitable material and/or materials. For example, the actuators25260may comprise of a metal material and may be actuated by way of additional articulation bands, cables, and/or plates, for example. In at least one instance, the actuators25260comprise of an electroactive polymer and are configured to be energized and de-energized to bend and/or advance/retract the actuators25260. Referring toFIG.99, the flex circuit25240is attached to the firing member25270. The flex circuit25240is spiral wrapped, or coiled, around the tube25230. In at least one instance, the coiling of the flex circuit25240is configured to reduce capacitive coupling between various electrical components within a shaft, for example, by fluctuating the position of the flex circuit25240radially within the shaft. In at least one instance, a control circuit is provided configured to actively mitigate capacitive coupling. An active inductor tunable impedance system can be employed to monitor and mitigate capacitive coupling within a surgical instrument assembly. In at least one instance, a control circuit is configured to provide active power management to electrical systems within a surgical instrument assembly. In such an instance, the control circuit is configured to detect capacitive coupling and actively adjust power delivery to reduce capacitive coupling between various electrical components within the surgical instrument assembly. In at least one instance, the flex circuit25240is wrapped around one or more components of a shaft assembly such that in a neutral, un-rotated state, the flex circuit25240is in a minimum tension state. In such an instance, rotation of components which would cause the flex circuit25240to rotate as well would cause the flex circuit25240to increase in tension as the flex circuit25240twists. The flex circuit25240can be configured to experience a maximum amount of twist-induced tension before a control circuit stops rotation. In various instances, rotation in a first direction causes the flex circuit25240to tighten around the shaft and rotation in the opposite direct causes the flex circuit25240to loosen around the shaft. Such a configuration provides a magnitude of slack in the system prior to rotation of components of the shaft assembly. In at least one instance, the flex circuit25240is manufactured in a coiled state. In at least one instance, the flex circuit25240is manufactured in a non-coiled state and is assembled into a neutral coiled state. Manufacturing the flex circuit25240in a coiled state can permit a thicker and/or wider flex circuit allowing for more signal transmission, for example. In at least one instance, the coiled configuration of the flex circuit25240reduces capacitive coupling between various signal transmission lines. In at least one instance, multiple ground layers or planes can be employed to surround radio frequency signals and/or isolate any stray fields generated within the surgical instrument assembly. FIGS.100and101depict an articulation system25300configured to be used with a surgical instrument assembly. The articulation system25300comprises a shaft25301, a biasing system25310, and an articulation joint25330comprising a plurality of electromagnets25351and a plurality of shaft segments25360configured to flex the articulation joint25330and, thus, the shaft25301, in an articulation plane. The biasing system25310is configured to bias the articulation system into a non-articulated configuration. The biasing system25310comprises a ratchet fork25311, translatable rack members25320and slave cables25340attached to the translatable rack members25320and a proximal shaft segment25360. The ratchet fork25311comprises toothed prongs25312configured to flex inwardly relative to each other when a spring force of the ratchet fork25311is overcome owing to translation of one or more of the translatable rack members25320. The toothed prongs25312are engaged with the translatable rack members25320such that, as the translatable rack members25320are pushed and/or pulled by the articulation joint25350, the toothed prongs25312ride against teeth25321of the rack members25320to provide a predetermined holding force to the rack members25320. The slave cables25340are attached to a distal end25322of each rack member25320to translate the pushing and/or pulling force of the articulation joint25350to the rack members25320. The rack members25320are attached to coil springs25330within a shaft assembly, for example, such that as the articulation joint25350is articulated, the coil springs25330are configured to push the rack members25320away from the articulation joint25350as slack is introduced to a corresponding slave cable25340and pulled toward the articulation joint25350as tension is applied to a corresponding slave cable25340by the articulation joint25350. To articulate the shaft25301with the articulation joint25350, the shaft segments25360are actuated in an accordion-like manner such that the electromagnets25351on one side of the articulation joint25350are energized to attract the electromagnets25351to each other to contract this side of the articulation joint25350and bend the shaft25301in a first direction. In at least one instance, the electromagnets25351on the other side of the articulation joint25350are de-energized, or not energized, so as to allow the electromagnets to move away from each other with the expansion of this other side of the articulation joint23350owing to the direction of articulation caused by the electromagnets25351which are energized. In at least one instance, the electromagnets25351on the expansion side of the articulation joint25350are energized in such a manner so as to repel the electromagnets on the expansion side of the articulation joint25350so as to aid expansion of this side of the articulation joint25350. Similarly, the articulation joint25350may be bent in the other direction by energizing the electromagnets in a manner opposite to the manner described above. In at least one instance, each electromagnet25351is energized simultaneously to attract and repel the desired electromagnets25351. In at least one instance, the proximal electromagnet25351attached to the slave cable is energized to activate contraction and/or expansion of the entire chain of electromagnets distal to the proximal electromagnet25351on one side of the articulation joint25350. In at least one instance, both sides of the articulation joint25350are energized corresponding to the desired configuration (expanded or contracted). Cables25352may contract and expand according to the desired configuration of the articulation joint25350. In at least one instance, the cables25352are configured to bias the articulation joint25350into a non-articulated configuration and are only compressed, or relaxed, and/or stretched, or pulled into tension, upon energizing the corresponding electromagnets25351. As discussed above, the biasing system25310is configured to bias the articulation joint25350into a non-articulated configuration. In at least one instance, the electromagnets25351are de-energized to allow the biasing system25310to push and pull the articulation joint25350into the non-articulated configuration. Referring toFIG.101, once the electromagnets25351are de-energized, the expanded coil spring25330will pull its corresponding rack member25320toward the articulation joint25350and the compressed coil spring25330will push its corresponding rack member25320away from the articulation joint25350. This pushing and pulling motion is applied to the slave cables25340and is configured to aid in moving the articulation joint25350into the non-articulated configuration. In at least one instance, the teeth25321and toothed prongs25312provide an audible sound to a user to indicate when the articulation joint25350has attained a fully non-articulation configuration. In at least one instance, the power supplied to the electromagnets25351can be varied to vary the articulation angle. For example, the more the user wants an end effector to articulate, the power supplied to the electromagnets25351can be progressively increased. In various instances, the cables25352,25340comprise a conductive thread, for example. The conductive thread can be monitored to detect the articulation angle of the articulation joint by monitoring the resistance and/or conductivity of the thread in real time and correlating the monitored resistance and/or conductivity to the articulation angle. In at least one instance, another set of electromagnets can be employed to allow for multi-axis articulation rather than single plane articulation. FIGS.102-104depict a surgical instrument shaft assembly25400configured for use with a surgical instrument such as those disclosed herein, for example. The shaft assembly25400comprises many of the same components as the surgical instrument1000. The shaft assembly25400may comprise various drive members configured to articulate an end effector, rotate an end effector about a longitudinal axis, and/or fire an end effector, for example. One or more of these drive members and/or components within a shaft assembly may be subject to tension and/or compression owing to the interaction of such drive members and/or components with other drive members and/or components of a surgical instrument employing the shaft assembly25400. In at least one instance, articulation of an end effector may cause a spine member to which an articulation joint may be attached to stretch and/or compress upon articulation of the end effector. This can be attributed to the attachment of the articulation joint to the spine member and the bending, or articulation, of the articulation joint. A core insert may aid in strengthening the shaft assembly25400and/or help define a maximum system stretch of the shaft assembly25400. The maximum system stretch may be defined by a maximum load and/or a maximum stretch length, for example. A core insert may prevent a member of a shaft assembly from prematurely failing. A core insert may also predefine the maximum system stretch of a shaft assembly so as to provide a predictable amount of stretch of one or more components of the shaft assembly and/or surgical instrument with which the shaft assembly is used. The shaft assembly25400comprises a spine member25410and the articulation joint1400. The shaft assembly25400further comprises a proximally extending articulation joint portion25430comprising pin apertures25431. The spine member25410comprises lateral slots25411defined therein each configured to receive an articulation actuator. The lateral slots25411can provide space between an outer shaft tube and the spine member25410for the articulation actuators. The spine member25410further comprises a primary slot25412configured to receive a drive member therethrough such as, for example, a primary drive shaft. The shaft assembly25400further comprises a core insert25420positioned with the spine member25410. The core insert25420may be insert molded and/or overmolded into the spine member25410. Other suitable manufacturing techniques are contemplated. The core insert25420comprises a proximal core member25421comprising a distal hook end25422. The distal hook end25422comprises a hook tab25423extending from the proximal core member25421. The core insert25420further comprises a distal core member25425comprising a proximal hook end25426. The proximal hook end25426comprises a hook tab25427extending from the distal core member25425. The hook tabs25423,25427face each other and cooperate to transmit stretching forces to each other through the spine member25410. The distal core member25425further comprises a distal mounting portion25428extending distally out of the spine member25410. The distal mounting portion25428comprises pin apertures25429defined therethrough. The shaft assembly25400further comprises pins2543configured to pin the articulation joint portion25430to the distal mounting portion25428by way of apertures25429. The pinned engagement between the distal mounting portion25428and the articulation joint portion25430may result in stretching, or tensile, forces being applied to the spine member25410. The core insert25420may help prevent the spine member25410from overstretching, for example. In at least one instance, the spine member25410comprises a first material and the core insert25420comprises a second material which is different than the first material. The first material may comprise a polymer material and the second material may comprise a metallic material. In at least one instance, the tensile strength of the second material is greater than the tensile strength of the first material. Such an arrangement can reduce weight, for example, of a surgical instrument which employs the shaft assembly25400while maintaining a desired system and/or shaft strength of the surgical instrument where significant actuation forces are present. For example, as an articulation actuator articulates the end effector and bends the articulation joint1400, stretching forces are applied to the spine member25410and the core insert25420can serve to counter these stretching forces. The material of the spine member25410positioned between the proximal core member25421and the distal core member25425may reduce capacitive coupling and/or electrically isolate the proximal core member25421from the distal core member25425. FIGS.105-111depict a plurality of articulation actuators configured for use with a surgical instrument. In at least one instance, the actuators discussed herein can be used for any suitable system requiring an actuator.FIG.105depicts a piezoelectric actuator25600comprising an energizing circuit25601and a piezoelectric bimorph polymer25610. The piezoelectric bimorph25610comprises an inner substrate layer25611and outer piezoelectric layers25612. The outer piezoelectric layers25612are configured to be energized in such a manner so as to bend the bimorph25610in the desired direction. The actuator25600may be used to articulate an end effector in an articulation plane. The substrate may comprise any suitable material. In at least one instance, the substrate comprises a material selected specifically for its rigidity and/or one or more other material properties, for example. In response to an electrical field, the layers25612are configured to bend in a desired direction. In at least one instance, the layers25611,25612are configured to splay relative to each other to compensate for radial differences in length upon bending within an articulation joint, for example. FIGS.106and107depict a piezoelectric bimorph actuator25800configured to be used with a surgical instrument. In at least one instance, one or more of the actuator25800is configured to be used to articulate an end effector. The actuator25800comprises an inner substrate layer25810and piezoelectric outer layers25820configured to be energized to bend the actuator25800in a desired direction. The polarization direction of the actuator25800can be pre-determined in order to predictable bend the actuator25800in the desired direction. The actuator25800further comprises an input circuit25801configured to actuate, or energize, the actuator25800. In at least one instance, both piezoelectric layers comprise the same polarization direction. In at least one instance, the same voltage signal is connected to the exposed outer surfaces of the piezoelectric layers. In at least on instance, the substrate layer is grounded. FIGS.108and109depicts a piezoelectric bimorph actuator25900configured to be used with a surgical instrument. In at least one instance, one or more of the actuator25900is configured to be used to articulate an end effector. The actuator25900comprises an input circuit25910and an actuation member25920. The actuator25900is configured to be energized to bend a bendable length25923of the actuator25900a pre-determined displacement amount25924and direction. In at least one instance, a portion25921of the actuator25900is inactive. In at least one instance, the actuator25900is energized in such a manner so as to bend the actuator25900in multiple directions to be able to articulate an end effector in multiple directions. Any suitable combination of the actuators described herein may be combined for use with a surgical instrument. For example, a piezoelectric bimorph actuator may be used in addition to an electroactive polymer actuator. In at least one instance, the circuit employed to energize various actuators disclosed herein can be specifically tuned depending on the desired amount of flexion of the actuator and/or depending on the force required to actuate the function of the end effector such as, for example, articulating an end effector. A chart25650is provided inFIG.112illustrating force generation vs. displacement of a piezoelectric actuator for use with a surgical instrument. FIG.111depicts an electroactive polymer (EAP) actuator25700configured to be used with a surgical instrument. In at least one instance, one or more of the actuator25700is configured to be used to articulate an end effector. In at least one instance, the actuator25700comprises a PVDF material (polyvinylidene fluoride). The actuator25700comprises an input mounting circuit25701and a bendable member25710. The bendable member25710comprises conductive layer25722(such as gold, for example), substrate layer25721(such as a PVDF layer, for example), and polypyrrole layers25723. FIG.112depicts a shaft assembly26000configured to permit distal end effector rotation within a surgical instrument. The shaft assembly26000comprises an outer shaft26010, a spine shaft26020, a primary drive shaft26030, and a distal head rotation drive shaft26040. In at least on instance, an end effector extends distally from the spine shaft26020so that the end effector can be rotated by the spine shaft26020. In at least one instance, the spine shaft26020rotates independently of the outer shaft26010. To rotate the spine shaft26020, a driving engagement surface26050is employed on the drive shaft26040and the inner diameter of the spine shaft26020such that, as the drive shaft26040is rotated, the spine shaft26020is rotated. In at least one instance, an elastomeric, friction-inducing material is positioned around the drive shaft26040and positioned around the inner diameter of the spine shaft26020. In at least one instance, the spine shaft26020comprises spline grooves and the drive shaft26040comprises teeth configured to engage the spine grooves. FIG.113depicts a shaft assembly26100configured to permit distal end effector rotation within a surgical instrument. The shaft assembly26100comprises an outer shaft26110, a spine shaft26120, a primary drive shaft26140, and a drive system configured to rotate the spine shaft26120. In at least on instance, an end effector extends distally from the spine shaft26120so that the end effector can be rotated by the spine shaft26120. In at least one instance, the spine shaft26120rotates independently of the outer shaft26110. To rotate the spine shaft26120, the drive system comprises windings26160positioned around shaft26150and magnets26130positioned on an inner diameter of the spine shaft26120. To rotate the spine shaft26120the windings26160are energized to cause the magnets26130to move around the windings26160. Various methods of locking rotational drive mechanisms are contemplated. For example, a system can rely on the resonant position holding torque of the magnets26130to hold an end effector in position relative to a shaft. In at least one instance, a mechanical ratchet is employed to hold an end effector in position relative to a shaft. In at least one instance, a sprung clutch system is employed to require a motor to overcome the sprung clutch system to unlock end effector rotation. In at least one instance, a ring gear is locked and unlocked to effect rotation of an end effector and to effector closure of a jaw relative to a fixed jaw. A planetary gear system can be employed to rotate different elements of a shaft assembly to effect different functions of a surgical instrument assembly, for example. FIG.114depicts a surgical instrument assembly26200comprising an outer shaft26210, a proximal spine member26220positioned within the outer shaft26210, and a distal spine member26230positioned within the outer shaft26210and configured to be rotated relative to the proximal spine member26220and, in at least one instance, the outer shaft26210. Rotation of the distal spine member26230can be employed to rotate an end effector of a surgical instrument, for example. The surgical instrument assembly26200further comprises a drive shaft26250configured to actuate a function of an end effector such as, for example, firing staples and/or cutting tissue. The proximal spine member26220comprises an annular flange portion26221and the distal spine member26230comprises an annular flange portion26231. The surgical instrument assembly26200further comprises one or more bearings26245positioned between the annular flange portions26221,26231such that the distal spine member26230can be rotated relative to the proximal spine member26220. The surgical instrument assembly26200further comprises a piezoelectric rotary motor. The piezoelectric rotary motor comprises a rotary piezoelectric member26240fixed within the assembly26200and one or more drive members26241configured to be actuated by the piezoelectric member26240. The surgical instrument assembly26200further comprises an electrical trace26260configured to energize the piezoelectric member26240to actuate the drive members26241in such a manner so as to apply a rotational torque to an inner drive surface26233. As a rotational torque is applied to the surface26233, the distal spine member26230is rotated to rotate an end effector, for example. In at least one instance, the piezoelectric rotary motor is configured to rotate the distal spine member26230in a clockwise direction and in a counter clockwise direction. In various instances, shaft assemblies for use with surgical instruments can contain electrical traces and/or wires, for example, extending through the shaft assembly from a proximal end to a distal end. The electrical traces may extend into an end effector attached to the distal end of the shaft assembly. In various instances, end effectors can be configured to rotate relative to the shaft. In various instances, end effectors and the shaft assembly to which the end effector is attached are configured to rotate relative to a proximal attachment interface and/or surgical instrument handle, for example. In such instances, the rotation of the end effector and/or shaft assembly may cause electrical traces to bind if the end effector and/or shaft assembly is over-rotated. Various ways of handling binding issues and/or contact issues with electrical traces positioned within shaft assemblies, which may be caused by rotation of an end effector and/or shaft assembly, are discussed herein. FIGS.115-117depict a limiter system26300configured to be used with a surgical instrument. The limiter system26300is configured to cease over-rotation of a drive train. In at least one instance, the limiter system26300is automatic and does not require input from a user to cease over-rotation of a drive train. In at least one instance, the limiter system26300requires input from a user. The limiter system26300comprises an actuator26310comprising a solenoid, for example. The actuator26310comprises a shaft26311comprising a spring26312and a distal end26313. The limiter system26300further comprises a gear26320. In at least one instance, the gear26320is part of a rotational drive train configured to actuate a function of an end effector. For example, the gear26320may be a part of a rotation drive train configured to articulate an end effector in multiple directions, rotate an end effector about a longitudinal axis relative to a shaft, clamp jaws of an end effector, and/or actuate a firing member of an end effector. As can be seen inFIG.115, the gear26320is free to rotate because the actuator26310is not actuated. In at least one instance, the actuator26310comprises a brake applied only in certain instances. The actuator26310may only be activated, or triggered, when a user desires and/or a surgical robot is programmed to limit movement of the gear26320. For example, as discussed above, the gear26320may comprise a component of a rotational drive train configured to articulate an end effector. In at least one instance, a user may activate an articulation drive train thereby rotating the gear26320. At any point, the user and/or a surgical robot may activate the actuator26310to stop articulation of an end effector.FIG.116illustrates the actuator26310in an actuated position. The distal end26313comprises teeth26314configured to engage teeth26321of the gear26320. However, at this point of rotation of the gear26320, a braking force applied to the gear26320may not be sufficient to cease rotation of the rotational drive train. The rotational drive train may be motorized and/or manual. Both can be ceased using the limiter system26300. In the position illustrated inFIG.116, an audible ratcheting noise may be heard during rotation of the gear26320. The spring26312is not fully compressed and will not apply a full braking force until the gear26320rotates to the position illustrated inFIG.117. As can be seen inFIG.117, the spring26312is fully compressed. In this position, the limiter system26300is configured to apply a maximum braking force to a rotational drive train by engaging teeth26323of the gear26320. Engagement between the teeth26314and the teeth26323results in maximum braking force because the teeth26323comprise the greatest radius of all of the teeth26321of the gear26320resulting in maximum compression of the spring26312. As the gear26320rotates from the position illustrated inFIG.116to the threshold position illustrated inFIG.117, an audible ratchet sound may increase in volume and/or slow in frequency. This may indicate to a user and/or a control circuit that maximum braking force is being approached. In at least one instance, a control circuit is configured to detect the braking force as it is applied and is configured to automatically shut off a motor actuating the rotational drive train connected to the gear26320. In at least one instance, a limiter system is applied with a substantially circular gear. In such an instance, an actuator may be progressively actuated to advance a shaft progressively toward the circular gear. In such an instance, a gradually increasing braking force may be applied to the gear. A control circuit may be configured to monitor and actively adjust the braking force during use of the limiter system. In at least one instance, a control circuit is configured to actuate the limiter system upon receiving input from one or more other control systems and/or circuits indicating that one or more systems of a surgical instrument are to be shut down during operation. In at least one instance, the limiter system26300is configured to be overridden such that the gear26320may be rotated past the threshold position where the maximum braking force is applied. In at least one instance, the limiter system26300is configured to be automatically activated upon an end of stroke for the function configured to be actuated by the rotational drive train. For example, as an end effector nears a maximum articulation angle, the limiter system26300may be activated to apply a braking force thereto. The maximum articulation angle may be detected by an encoder on an articulation motor and/or a sensor configured to detect directly the angle of articulation, for example. In various instances, the limiter system26300may be deactivated at any point a user and/or control circuit seeks to continue uninterrupted actuation of the rotational drive train. In at least one instance, audible ratcheting noises may be heard during rotational of the gear26320in both the counterclockwise direction and the clockwise direction. If the actuator26310is actuated, an audible ratchet noise is heard during rotation of the gear26320in either direction. In at least one instance, the limiter system26300is configured to provide only feedback of the threshold position being reached and is not configured to affect actuation of a rotational drive train for which it provides feedback. In other words, the limiter system26300is only an indicator system and does not apply braking force to the function of the end effector being monitored. In at least one instance, the limiter system26300provides a hard stop for the function of the end effector. Once the threshold position is reached, a motor actuating the rotational drive system cannot overcome the braking force applied thereto by the limiter system26300. In various instances, a control circuit configured to actuate the limiter system26300comprises a counter rotation feature. Once the gear23620reaches the threshold position, the control circuit may deactivate the actuator26310and counter rotate the gear26320to a non-threshold position. Once the gear is26320is counter rotated, a user may regain control of actuation of the rotational drive train. In at least one instance, a user may indicate the need for rotation of the rotational drive train beyond the threshold position. In such an instance, a user may indicate that further rotational is desired. If the user indicates that further rotation is desired, the actuator26310may be automatically deactivated and the rotational drive train is free to rotate. In at least one instance, an absolute maximum rotation is predetermined and cannot be surpassed. In such instance, a soft maximum threshold may be predetermined allowing for some rotation passed the soft maximum threshold but not beyond the absolute maximum rotation. The absolute maximum rotation may be defined by mechanical limits, for example. The soft maximum threshold may be defined by an operational limit which does not overstress any components, for example. In at least one instance, the counter rotation feature is inhibited if jaws of an end effector sense a fully clamped state onto tissue. This can reduce the likelihood of accidentally opening the jaws and losing grip on targeted tissue. In at least one instance, braking force may be applied during several rotations of the gear26320. In such an instance, shaft rotation of the rotational drive train may be tracked and the braking force applied by the actuator26310is gradually increased as the gear26320rotates. FIGS.118-120depict a rotary actuation system26400for use with a surgical instrument. The rotary actuation system comprises a mechanical limiting system configured to prevent over-rotation, or actuation, of a drive system. The drive system may comprise an articulation drive system, an end effector rotation drive system, a jaw clamping and/or unclamping drive system, and/or a firing member drive system, for example. The rotary actuation system26400comprises a motor26410, a variable screw26420configured to be rotated by the motor26410, and a drive nut26430configured to be linearly actuated by the screw26420. The motor26410is configured to rotate the screw26420to actuate the drive nut26430to actuate a function of a surgical instrument. The drive nut26430may be connected to a drive member configured to actuate a function of the surgical instrument. While any suitable function may be actuated by the rotary actuation system,26400, the rotary actuation system26400will be described in connection with an articulation system. The screw26420comprises variable threads26425, an inner section26421, and outer sections26422extending from the inner section26421. The outer sections26422extend from the inner section26421gradually increasing a thread diameter of the threads26425. In at least one instance, the thread diameter is varied along a screw axis defined by the screw26420. In at least one instance, the thread pitch is varied along the screw axis defined by the screw26420. In at least one instance, the thread diameter and the thread pitch are varied along the screw axis. In at least one instance, a thread profile varies along the length of the screw26420. The varied thread profile is engaged with the drive nut26430such that engagement of threads26431of the drive nut26430and threads26425of the screw26420varies along the length of the screw26420. As the screw26420is rotated in a first direction, the drive nut26430is configured to move in a corresponding first direction toward an outer section26422of the screw26420. In at least one instance, movement of the drive nut26430toward an outer section26422corresponds to articulation of an end effector. As the drive nut26430moves toward an outer section26422, the threaded engagement between the nut26430and the screw26420tightens owing to the varied thread profile. This tightened engagement may cause increased load on the motor26410. This increased load can be monitored and detected. The detected load can be conveyed to a user and/or a control circuit to indicate to a user and/or a control circuit that the drive nut26430is nearing an end of stroke position. In at least one instance, the motor26410is automatically slowed so as to slow the velocity of the drive nut26430near the end of stroke position. In at least one instance, the motor26410is automatically stopped upon detecting a threshold load. In at least one instance, the drive nut26430is automatically counter-rotated at least partially to decrease load on the motor26410. In at least one instance, the outer ends26422provide a hard stop for an actuation stroke, such as an articulation stroke, for example. In at least one instance, the distance capable of being traveled by the drive nut26430corresponds to mechanical limitations by the corresponding actuation stroke such as, for example, maximum articulation angle. In at least one instance, the threads26431comprise a non-variable thread profile while the threads26425comprise a variable thread profile. In at least one instance, the threads26431also comprise a variable thread profile in addition to the threads26425of the screw26420. In at least one instance, the motor is configured to stall upon reaching a maximum rotational limit. In at least one instance, the threaded engagement locks the nut26430into place upon reaching the maximum rotational limit. In at least one instance, a control circuit is configured to unlock the drive nut26430after reaching the maximum rotational limit by re-activating the motor26410to rotate the screw26420in an opposite direction. In at least one instance, a larger torque may be required to unlock the drive nut26430from its maximum rotational limit position. In at least one instance, feedback is provided as the maximum rotational limit position is approached. For example, a control circuit may provide audio and/or tactile feedback to a user, based on detected increase motor load, as the drive nut26430approaches the maximum rotational limit position. In at least one instance, a control circuit is configured to automatically adjust a control motion of actuation of the motor26410before, during, and/or after the drive nut26430reaches the maximum rotational limit position. The drive nut26430comprises a maximum rotational limit position on both outer sections26422of the screw26420. In at least one instance, a hard stop is provided to prevent irreversible binding of the nut26430and the screw26420. FIG.121depicts a segmented ring contact system26500for use with a surgical instrument assembly. The segmented ring contact system26500may be employed between two or more components where electrical transmission is desired between two or more of the components and one or more of the components are configured to be rotated relative to one or more other components. The segmented ring contact system26500is configured to provide redundant slip ring contacts within a shaft assembly for a surgical instrument, for example. The segmented ring contact system26500comprises an outer segmented contact system26510comprising a plurality of slip ring contact segments26511and an inner segmented contact system26520comprising a plurality of slip ring contact segments26521. As can be seen inFIG.121, the slip ring contact segments26511span gaps defined between the slip ring contact segments26521and the slip ring contact segments26521span gaps defined between the slip ring contact segments26511. In at least one instance, the contact system26500may mitigate fluid shorting between contacts by providing multiple segments as opposed to a single slip ring contact spanning a 360 degree length of a shaft, for example. If one segment shorts out, another segment may provide a redundant means for transmitting electrical signals. In at least one instance, the segments26511and the segments26521comprise different resistance values which can be detected and monitored by a control circuit. Such an arrangement may indicate to a user and/or control circuit, for example, which contacts are transmitting electrical signals and which contacts are not transmitting electrical signals. Such an arrangement may also allow a control circuit to determine rotational shaft position. FIGS.122-127depict various electrical transmission arrangements for use with surgical instrument assemblies. In various instances, the electrical transmission arrangements are configured to transmit electrical signals between a first shaft and a second shaft. The first shaft may be attached to a surgical robot and/or handle, for example, and the second shaft may comprise an end effector attached to a distal end thereof. In at least one instance, the electrical transmission arrangements are configured to transmit electrical signals between sensors, processors, and/or power sources, etc., of the first shaft assembly and the second shaft assembly. For example, the second shaft may comprise a motor requiring power from the first shaft and/or a component upstream of the first shaft. Another example may include receiving electrical signals from sensors positioned on the second shaft and/or end effector attached to the second shaft. Other systems requiring electrical transmission between the first shaft assembly and second shaft assembly are contemplated. The electrical transmission arrangements disclosed herein can be configured to help prevent fluid shorting of the transmission arrangement, for example. FIG.122depicts a surgical instrument assembly26600comprising a first shaft26610, a second shaft26620, and an electrical transmission arrangement26640. The second shaft26620is rotatable relative to the first shaft26610. In at least one instance, the first shaft26610is rotatable relative to the second shaft26620. In at least one instance, the first shaft26610and the second shaft26620are rotatable relative to each other. In at least one instance, the second shaft26620comprises an end effector attached to a distal end thereof. The electrical transmission arrangement26640comprises electrical traces26611and first contacts26612connected to the electrical traces26611and positioned in an inner channel26613of the first shaft26610. The first contacts26612may comprise slip ring contacts, for example, extending around the entire inner diameter of the channel26613. In at least one instance, the first contacts26612comprise isolated contact segments. The electrical transmission arrangement26640further comprises electrical traces26621and second contacts26622connected to the electrical traces26621and positioned on an outer surface26623of the second shaft26620. The second contacts26622may comprise slip ring contacts, for example, extending around the entire outer diameter of the outer surface26623of the second shaft26620. The second contacts26622are configured to contact the first contacts26612to transmit electrical signals therebetween. The second contacts26622are configured to maintain electrical contact with the first contacts26612during rotation of the second shaft26620relative to the first shaft26610. The surgical instrument assembly26600further comprises a channel26630between the first shaft26610and the second shaft26620. Fluid and/or debris from a patient may flow into the channel26630during an operation. The electrical transmission arrangement26640may help prevent fluid and/or debris from flowing into the channel26630. In at least one instance, each contact26612is configured to supply and/or receive different electrical signals for different electrical systems. In at least one instance, the contacts26612,26622act as redundant contacts. FIG.123depicts a surgical instrument assembly26700. The surgical instrument assembly26700comprises many of the same components of the surgical instrument assembly26600. The surgical instrument assembly26700further comprises grommets26710positioned between each set of contacts26612,26622. The grommets26710may comprise of a rubber material, for example. The grommets26710may help prevent fluid and/or debris from flowing into the channel26630. FIG.124depicts a surgical instrument assembly26800. The surgical instrument assembly26800comprises many of the same components of the surgical instrument assembly26600. The surgical instrument assembly26800further comprises a grommet26810positioned away from the contacts26612,26622. The grommet26810may help prevent fluid and/or debris from flowing into the channel26630and toward the contacts26612,26622well away from the contacts26612,26622. FIG.125depicts a surgical instrument assembly26900comprising a first shaft26910, a second shaft26920, and an electrical transmission arrangement26940. The second shaft26920is rotatable relative to the first shaft26910. In at least one instance, the first shaft26910is rotatable relative to the second shaft26920. In at least one instance, the first shaft26910and the second shaft26920are rotatable relative to each other. In at least one instance, the second shaft26920comprises an end effector attached to a distal end thereof. The electrical transmission arrangement26940comprises electrical traces26911and first contacts26912A,26912B connected to the electrical traces26911and positioned in an inner channel26913of the first shaft26910. The first contacts26912A,26912B comprise isolated contact segments. The contacts26912A and the contacts26912B are positioned opposite each other. This positioning may help prevent contacts26912A,26912B from shorting out where fluid flows into an upper portion of the channel26930and not a lower portion of the channel26930. The electrical transmission arrangement26940further comprises electrical traces26921and second contacts26922connected to the electrical traces26921and positioned on an outer surface26923of the second shaft26920. The second contacts26922may comprise slip ring contacts, for example, extending around the entire outer diameter of the outer surface26923of the second shaft26920. The second contacts26922are configured to contact the first contacts26912A,26912B to transmit electrical signals therebetween. The second contacts26922are configured to maintain electrical contact with the first contacts26912A,26912B during rotation of the second shaft26920relative to the first shaft26910. The surgical instrument assembly26900further comprises a channel26930between the first shaft26910and the second shaft26920. Fluid and/or debris from a patient may flow into the channel26930during an operation. The surgical instrument assembly26900further comprises a grommet26931configured to prevent fluid and/or debris from flowing into the channel26930. FIG.126depicts a surgical instrument assembly27000comprising a first shaft27010, a second shaft27020, and an electrical transmission arrangement27040. The second shaft27020is rotatable relative to the first shaft27010. In at least one instance, the first shaft27010is rotatable relative to the second shaft27020. In at least one instance, the first shaft27010and the second shaft27020are rotatable relative to each other. In at least one instance, the second shaft27020comprises an end effector attached to a distal end thereof. The electrical transmission arrangement27040comprises first electrical contacts27012positioned within an annular slot27011defined in an inner diameter27013of the first shaft27010. The electrical transmission arrangement27040further comprises a second electrical contact27021, such as a slip ring contact, for example, positioned on an outer diameter27022of the shaft27020. The first electrical contacts27012are configured to maintain electrical contact as one of the shafts27010,27020rotates relative to the other shaft27010,27020. This contact arrangement may be referred to as a blade-style electrical contact arrangement. The second electrical contact27021is configured to be positioned at least partially within the annular slot27011and may be referred to as a blade contact. FIG.127depicts a surgical instrument assembly27100comprising a first shaft27110, a second shaft27120, and an electrical transmission arrangement27140. The second shaft27120is rotatable relative to the first shaft27110. In at least one instance, the first shaft27110is rotatable relative to the second shaft27120. In at least one instance, the first shaft27110and the second shaft27120are rotatable relative to each other. In at least one instance, the second shaft27120comprises an end effector attached to a distal end thereof. The electrical transmission arrangement27140comprises first electrical contacts27113positioned within annular slots27112defined in an inner diameter27111of the first shaft27110. The electrical transmission arrangement27140further comprises second electrical contacts27123positioned on blade wheels27122positioned on an outer diameter27121of the shaft27120. The first electrical contacts27113and second electrical contacts27123are configured to maintain electrical contact with each other as one of the shafts27110,27120rotates relative to the other shaft27110,27120. The second electrical contacts27123are configured to be positioned at least partially within the annular slots27112. The blade wheels27122may help alleviate shorting of the contacts27123,27113by reducing the amount of exposed electrical contact area exists within the electrical transmission arrangement27140. FIGS.128and129depict inductive coil systems28000,28100configured to be used with a surgical instrument shaft assembly. Employing wired electrical traces between components configured to rotate relative to each other such as, for example, a shaft assembly and an end effector. The inductive coil system28000comprises a first inductive coil28010and a second inductive coil28020. In at least one instance, the coil28010comprises a transmitter coil and the coil28020comprises a receiver coil. The coils28010,28020can be configured to transmit electrical signals therebetween. In at least one instance, one of the coils28010,28020is positioned on a first component and the other of the coils28010,28020is positioned on a second component configured to rotate relative to the first component. In at least one instance, the distance between the coils28010is less than the diameter of ach coil28010,28020. The coil system28100comprises a first inductive coil28110and a second inductive coil28120. In at least one instance, the coil28110comprises a transmitter coil and the coil28120comprises a receiver coil. The coil28120comprises a diameter which is less than the diameter of the coil28110. In at least one instance, multiple coil systems are employed with a surgical instrument assembly. For example, one or more coil systems can be utilized to transmit power and one or more coil systems can be utilized to transmit data. FIGS.130and131depict an electroactive polymer system29000for use with a surgical instrument assembly. The system29000comprises an electroactive polymer29010and an input circuit29020. The system29000can be used as an actuator for a surgical instrument assembly such as, for example, an articulation actuator.FIG.131illustrates the polymer29010in an energized state.FIG.130illustrates the polymer29010in an un-energized state. In at least one instance, the polymer29010is employed to rotate an end effector relative to a shaft. One end of the polymer29010can be fixed to the shaft and the bendable end of the polymer29010can be attached to the end effector. The polymer29010can be configured to be twisted to cause rotation of an end effector relative to a shaft. The material selected for the system29000can be selected based on material limitations to predefine the amount of deflection required for the actuation. End effectors of surgical instruments, including the components thereof, experience significant forces upon them during a single firing stroke. Such forces lead to equipment wear, which can ultimately lead to ineffective tissue treatment, for example. In various instances, a clinician may want to use a new cutting element for each tissue cutting stroke during a particular surgical procedure. The disposable end effector assemblies described herein allow for a clinician to interchangeably replace one or more components of the end effector from a particular surgical instrument. FIGS.132-138depict an end effector30000for use with a surgical instrument. The end effector30000comprises a channel30100, an anvil30200, and a cartridge30300. In various instances, the channel30100is configured to fixedly, or non-replaceably, extend from an elongate shaft30500of the surgical instrument. In other instances, the channel30100is configured to be replaceably attached to the elongate shaft30500. In any event, the channel30100is configured to extend from the elongate shaft30500at a point distal to an articulation joint. The anvil30200comprises an elongate slot30280defined therein. The elongate slot30280extends from a proximal end30202toward a distal end30204of the anvil30200and is configured to receive a first camming member30406of a firing member30400. An anvil projection30210extends from a sidewall, or tissue stop,30208near the proximal end30202of the anvil30200. The anvil projection30210defines a pivot joint about which the anvil30200is movable relative to the cartridge30300. The anvil projection30210comprises an aperture30212defined therein. The aperture30212is sized to fittingly receive a cartridge projection30310therein. The cartridge projection30310extending through at least a portion of the anvil projection30210establishes a coupling and/or attachment between the cartridge30300and the anvil30200while also maintaining component alignment. In various instances, the cartridge30300and the anvil30200are coupled together during the manufacturing and/or packaging process. In other instances, a clinician is able to selectively choose between various combinations of compatible anvils and cartridges prior to use of the assembly with a surgical instrument. As shown inFIG.134, the cartridge30300comprises a cartridge pivot member30350from which the cartridge projection30310extends. The cartridge pivot member30350serves as an electronics interface to the channel30100when the cartridge30300is seated therein. In various instances, the cartridge pivot member30350is comprised of metal while the remaining cartridge body is comprised of a plastic material, for example. In various instances, the cartridge30300comprises a plurality of staple cavities30360defined therein, at least one electrode30370, and a longitudinal slot30380extending from a proximal end towards a distal end. The at least one electrode30370is similar to longitudinal electrode1925, whose functionality is described in greater detail with respect toFIGS.1and6. In various instances, the at least one electrode30370is an RF electrode. The longitudinal slot30380is configured to receive a portion of the firing member30400as the firing member30400translates through the end effector30000during a firing stroke. Staples are removably positioned in the staple cavities30360. In other instances, the cartridge may only comprise staple cavities or may only comprise an RF electrode. In any event, the cartridge30300is configured to be removably seated in the channel30100. The cartridge30300further comprises a lateral projection30320extending from a cartridge sidewall. Sidewalls of the channel30100comprise a notch30120defined in a distal portion thereof. The notch30120is sized to receive the lateral projection30320of the cartridge30300therein as the cartridge30300is seated in the channel30100. In addition to securing the cartridge30300to the channel30100, the notch30120ensures that the assembly comprised of the cartridge30300and the anvil30200is appropriately aligned with the channel30100, and thus the elongate shaft30500. The act of installing the assembly comprised of the cartridge30300and the anvil30200into the channel30100also serves to connect various electrical components30700throughout the end effector30000. The sidewalls of the channel30100further comprise a pivot notch30110defined therein. The pivot notch30110comprises a size and/or geometry configured to receive the anvil projection30210therein. As shown inFIGS.132and133, the pivot notch30110is angled in an effort to prevent the assembly of the anvil30200and cartridge30300from unwantedly detaching from the channel30100, for example. When the disposable assembly comprised of the anvil30200and the cartridge30300are fully seated in the channel30100, the anvil30200is not physically, or directly, attached to the elongate shaft30500. Stated another way, the anvil30200is only physically, or directly, coupled to the cartridge30300and the channel30100. As shown inFIG.133, the channel30100further comprises a drive screw30150positioned therein prior to the attachment of the staple cartridge30300thereto. A distal end30104of the channel base30108comprises a mounting interface30130for securing a distal end30154of the drive screw30150. A firing member30400is mounted on the drive screw30150prior to the staple cartridge30300being seated in the channel30100. FIGS.135-138show the progression of seating the disposable assembly comprising the anvil30200and the cartridge30300into the channel30100. As shown inFIG.135, the anvil30200is coupled to the cartridge30300as an assembly, and the channel30100is attached to the elongate shaft30500at a point distal to any articulation joint; however, the anvil30200and the cartridge30300are completely detached from the channel30100. A first stage of seating the disposable assembly in the channel30100is shown inFIG.136. As the disposable assembly is brought toward the channel30100, the proximal end30202of the anvil30200is tilted toward the base30106of the channel30100, while the distal end30204of the anvil30200, and thus the disposable assembly, is tilted slightly away from the base30106of the channel30100. Initial contact is made between the anvil projection30210and the pivot notch30110of the channel30100. Notably, the lateral projection30320is not yet aligned with the notch30120of the channel30100. In the first stage, the first camming member30406of the firing member30400is slid into a proximal portion of the elongate slot30280of the anvil30200. Additionally, the drive screw30150is not yet aligned with the longitudinal slot30380of the cartridge30300. Such misalignment prevents the cartridge30300from being fully seated in the channel30100. A second stage of seating the disposable assembly in the channel30100is shown inFIG.137. As the anvil projection30210is slid completely into the pivot notch30110of the channel30100, the disposable assembly moves distally within the channel30100, disengaging the first camming member30406of the firing member30400from the elongate slot30280of the anvil30200. Such distal movement brings the lateral projection30320in line with the notch30120; however, the distal end of the cartridge30300remains elevated. FIG.138depicts the disposable assembly fully seated in the channel30100. At such a point, the anvil projection30210is completely housed within the pivot notch30110, the lateral projection30320is completely housed within the notch30120, and the drive screw30150is completely housed within the longitudinal slot30380of the cartridge30300. Such alignment between the cartridge30300and the drive screw30150allows for the cartridge30300and the anvil30200disposable assembly to be fully seated in the channel30100. When the disposable assembly is fully seated in the channel30100, all electrical components, such as flex circuits and/or sensor arrays,30700are coupled and in communication with the channel30100and/or the elongate shaft30500of the surgical instrument. In various instances, the disposable assembly comprised of the cartridge30300, the anvil30200, and various flex circuits30700is only intended for a single use. Stated another way, upon completion of a single firing stroke, the cartridge30300, the anvil30200, and the associated flex circuits30700are removed, or unseated, from the channel30100leaving behind the drive screw30150and the firing member30400. In such instances, the drive screw30150and the firing member30400are intended to be used for more than one firing stroke. The channel30100, including the drive screw30150and the firing member30400, can be detached from the elongate shaft30500and disposed of after being used for a pre-determined number of firing strokes, or upon becoming defective, for example. FIGS.139-146depict an end effector31000for use with a surgical instrument. Similar to the end effector30000, the end effector31000comprises a channel31100, an anvil31200, and a cartridge31300. The end effector31000is detachably, or replaceably, coupled to an elongate shaft31500of the surgical instrument at a point distal to any articulation joint. Stated another way, the end effector31000is configured to be disposed of after a pre-determined number of firing strokes, such as one, for example. As shown inFIG.146, the end effector31000comprises a firing member31400as part of a disposable portion. In such instances, a new cutting element, for example, is present every time the end effector31000is replaced. Similar to the cartridge30300, the cartridge31300can comprise staple cavities, an RF electrode, and/or any suitable combination of features. The cartridge31300further comprises a lateral projection31320extending from a cartridge sidewall. Sidewalls of the channel31100comprise a notch31120defined in a distal portion thereof. The notch31120is sized to receive the lateral projection31320of the cartridge31300therein as the cartridge31300is seated in the channel31100. In addition to securing the cartridge31300to the channel31100, the notch31120ensures that the cartridge31300is appropriately aligned with the channel31100. While the end effector31000is shown as being detachably coupled to the elongate shaft31500, the cartridge31300is also replaceably seated in the channel31100. As shown inFIG.141, the anvil31200comprises a flex circuit31700having traces arranged on a sidewall, or tissue stop, of the anvil31200near a proximal end. When pivotally coupled to the channel31100, the anvil traces are in electrical contact with a flex circuit comprising traces31151positioned on the channel. A coupling member31800serves as an attachment interface between elongate shaft31500and the assembly formed of the channel31100, the anvil31200, and the cartridge31300. A distal end of the elongate shaft31500is shown inFIG.140prior to attachment of the coupling member31800and end effector31000thereto. The distal end of the elongate shaft31500comprises various attachment members configured to secure and/or align the elongate shaft31500with the end effector31000in addition to coupling the drive systems and/or electrical connections. A proximal end of the coupling member31800is configured to interface with the distal end of the elongate shaft31500. The proximal end of the coupling member31800is shown inFIG.142prior to attachment to the elongate shaft31500. The coupling member31800comprises complementary features to those of the elongate shaft31500. More specifically, the distal end of the elongate shaft31500comprises a drive shaft31600extending therefrom. A channel31860is defined in the coupling member31800that is sized to closely receive the drive shaft31600therein. The drive shaft31600extends through the channel31860for ultimate attachment to a drive screw within the channel31100and/or cartridge31300of the end effector31000. As described in greater detail throughout, a flex circuit, or electrical traces,31550extend through the elongate shaft31500to a control circuit and/or processor within a proximal housing, for example. The flex circuit31550of the elongate shaft31500is electrically coupled to a flex circuit31850on the coupling member31800. The flex circuit31850on the coupling member31800is in electrical communication with the flex circuit31700on the anvil31200. Sensed parameters and/or component statuses can be communicated through the chain of flex circuits when the end effector31000is coupled to the elongate shaft31500via the coupling member31800. The distal end of the elongate shaft31500further comprises an attachment member31570and an alignment pin31580. The proximal end of the coupling member31800comprises an attachment groove31870sized to receive the attachment member31570and an alignment groove31880sized to receive the alignment pin31580when the end effector31000is attached to the elongate shaft31500. FIGS.142-146show the progression of attaching the disposable end effector31000comprising the channel31100, the anvil31200, and the cartridge31300to the elongate shaft31500. As shown inFIG.142, the cartridge31300is fully seated in the channel31100and the anvil30200is coupled thereto as an assembly. The end effector31000further comprises a coupling member31800for replaceably attaching the end effector31000to the elongate shaft31500at a point distal to any articulation joint. A first stage of attaching the disposable end effector assembly to the elongate shaft31500is shown inFIG.143. As the coupling member31800of the disposable assembly is brought toward the distal end of the elongate shaft31500, initial contact is made between the attachment member31570extending from the elongate shaft31500and the attachment groove31870defined in the coupling member31800. The drive shaft31600is initially received within the channel31860; however, the drive shaft31600has not yet been coupled to a drive screw31150. Notably, the flex circuits31850,31750are misaligned and out of physical contact in the first stage of attachment. Furthermore, the alignment pin31580is out of alignment with the alignment groove31880defined in the coupling member31800. Such misalignment prevents the disposable end effector31000from being fully attached to the elongate shaft31500. A second stage of attaching the disposable end effector assembly to the elongate shaft31500is shown inFIG.144. Contact between the proximal end of the coupling member31800and the alignment pin31580causes the alignment pin31580to be spring biased away from the coupling member31800thereby allowing the disposable end effector31000and/or the elongate shaft31500to be freely rotated with respect to one another. Such rotation of the disposable end effector31000and/or the elongate shaft31500with respect to one another begins to rotatably attach the drive shaft31600to the drive screw31150; however, the flex circuits31850,31550are still out of physical contact and the alignment pin31580has not yet been received by the alignment groove31880defined in the coupling member31800. FIG.145depicts the disposable end effector assembly fully attached to the elongate shaft31500. At such a point, the alignment pin31580is biased back toward the coupling member31800and is completely housed within the alignment groove31880defined within the coupling member31800. As shown inFIG.146, complete operational coupling between the drive shaft31600and the drive screw31150is achieved when the disposable end effector assembly is fully attached to the elongate shaft31500. Furthermore, such alignment between the end effector31000and the elongate shaft31500also ensures alignment and/or physical contact between the flex circuits31850,31550. When the disposable assembly is fully attached to the elongate shaft31500, all electrical components, including flex circuits30700and/or sensor arrays positioned in the anvil31200, cartridge31300, and/or channel31100are coupled and in communication with the elongate shaft31500of the surgical instrument. In various instances, the disposable assembly comprised of the channel31100, the anvil31200, the cartridge31300, and various flex circuits31700is only intended for a single use. Stated another way, upon completion of a single firing stroke, the end effector31000, including the firing member31400, and the associated flex circuits31700are removed, or detached, from the elongate shaft31500. Detachment can occur after being used for a pre-determined number of firing strokes, or upon becoming defective, for example. FIGS.147and148depict an end effector32050configured to be replaceably attached to an elongate shaft32500of a surgical instrument. The end effector32050has a channel32100, an anvil32200, and a cartridge32300. The cartridge32300is sized and/or configured to be seated in the channel32100. As described in greater detail with respect toFIGS.132-138, in various instances, the anvil32200and the cartridge32300are pivotally attached to one another about a pivot joint32210prior to the cartridge32300being seated in the channel32100. In various instances, the anvil32200is configured to be pivotally attached to the channel32100. The channel32100comprises a proximal end32052and a distal end32054. The proximal end32052of the channel32100comprises an attachment member32056extending proximally therefrom. The attachment member32056is configured to releasably secure the end effector32050to an elongate shaft32500of the surgical instrument. WhileFIGS.147and148show the attachment member32056extending from the proximal end of the channel32100, the attachment member32056can extend from any suitable component of the end effector32050such as the anvil32200or the cartridge32300. In various instances, the attachment member32056is integrally formed with the particular end effector component. In other instances, the end effector32050comprises an adapter attached to a proximal end of the end effector32050. The adapter comprises the attachment member32056for securement of the end effector32050to the elongate shaft32500. A distal end of the elongate shaft32500comprises a securement door32510movable between an open position and a closed position about a pivot joint32520. In various instances, the securement door32510remains in the closed position until motivated into the open position. In such instances, the securement door32510is in the closed position prior to attachment of an end effector32050thereto. The attachment member32056of the end effector32050can be used to bias the securement door32510into an open position. Alternatively, a clinician can motivate the securement door32510into the open position prior to attaching the end effector32050to the elongate shaft32500. The securement door32510can remain biased open in its open position until an attachment member32056is appropriately positioned in the groove and/or until the securement door32510is motivated into the closed position. In its open position, as shown inFIG.147, the securement door32510exposes a groove sized to receive the attachment member32056of the end effector32050therein. Stated another way, when the securement door32510is in the open position, a path is cleared for the attachment member32056to be positioned in the groove of the elongate shaft32500. In various instances, the securement door32510can return to its closed position when the attachment member32056is appropriately positioned in the groove. In other instances, a clinician can motivate the securement door32510into the closed position. A sensor assembly can communicate a status and/or position of the securement door32510to a processor. In such instances, the processor is configured to prevent use of the surgical instrument while the securement door32510is in the open position and/or defective. The securement door32510has a distal end32512with a latch geometry. The attachment member32056comprises a proximal portion having a first thickness and a distal portion having a second thickness. As shown inFIGS.147and148, the first thickness is greater than the second thickness. Such a geometry allows for the distal end32512of the securement door32510and/or the corresponding geometry of the groove to retain the attachment member32056therein. The geometry of the groove prevents unwanted movement of the attachment member32056and/or maintains alignment of the end effector32050and the elongate shaft32500, for example. In various instances, the attachment member32056has a press-fit relationship with the groove; however, any suitable mechanism that maintains attachment and/or alignment between the components is envisioned. In various instances, a geometry and/or size of the attachment member32056does not correspond to a geometry and/or size of the channel Such a mismatch in geometry and/or size prevents the end effector32050from being fully attached to and/or aligned with the elongate shaft32500. In such instances, the firing drive(s) and/or electronic components are not connected and the surgical instrument is non-operable. Should the attachment member32056be too large to fit within the groove, the securement door32510will be unable to reach its fully closed position, and an alert can be sent to a processor as described in greater detail herein. Similarly, a sensor assembly can detect an absence of contact between the attachment member32056and the barriers of the groove, suggestive of an attachment member32056comprising an inappropriately small geometry for use with the surgical instrument. In such instances, the processor prevents the use of the surgical instrument. The end effector32050further comprises a firing member32400mounted on a drive screw. A drive shaft32600, similar to drive shaft1660, extends through the elongate shaft32500and is coupled with the drive screw of the end effector32050upon attachment of the end effector32050to the elongate shaft32500. Subsequent rotation of the drive screw causes the firing member32400to translate through the end effector32050. The firing member32400comprises a first camming member32406configured to engage the anvil32200as the firing member32400translates through the end effector32050, a second camming member32408configured to engage the channel32100as the firing member32400translates through the end effector32050, and a cutting element32410. As discussed in greater detail throughout, the firing member32400can be mounted on a drive screw in the channel32100prior to attachment of the cartridge32300thereto or the firing member32400can be an integral component with the cartridge32300prior to seating the cartridge32300in the channel32100. In any event, as shown inFIGS.149and150, the firing member32400comprises a projection32420having a keyed profile32425on a proximal end32402of the firing member32400. The keyed profile32425is configured to be received within a corresponding groove32610formed in a distal end32604of the drive shaft32600. As the end effector32050is brought into alignment with the elongate shaft32500, the keyed profile32425of the projection32420is configured to be positioned in the groove32610. In various instances, the groove32610comprises a larger geometry than the keyed profile32425of the firing member32400. However, the groove32610comprises a notch configured to catch the keyed profile32425of the firing member32400and prevent the firing member32400from translating distally out of connection with the drive shaft32600. In various instances, the width of the groove32610is similar to the width of the keyed profile32425. Such a similarity in width allows for the keyed profile32425to comfortably fit into the groove32610yet prevents unwanted proximal translation and/or rotation of the keyed profile32425within the groove32610. FIGS.151and152depict a reinforce anvil33200having an anvil33250and an anvil plate33260circumferentially welded thereto. The anvil33250comprises a projection33210for pivotal attachment to a cartridge and/or a channel as described in greater detail herein. The anvil plate33260bridges, or crosses, at least partially over top of the pivot joint formed about the projection33210. While the anvil plate33260is described as being welded to the anvil33200, any attachment method that provides suitable reinforcement to the anvil33200is envisioned. The reinforced anvil33200provides increased strength to allow the reinforced anvil33200to withstand greater loads experienced during closure and/or firing strokes, especially over the pivotal attachment joint, for example. As shown inFIG.153, the reinforced anvil33200is pivotally attached to a channel33100of an end effector33000. The end effector33000further comprises a cartridge33300seated in the channel33100. A firing member33400is positioned in the end effector33000. The firing member33400has a first camming member33406configured to engage an elongate slot33220of the anvil33200as the firing member33400translates through the end effector33000, a second camming member33408configured to engage the channel33100as the firing member33400translates through the end effector33000, and a cutting element33410. The anvil plate33260comprises a first thickness A at a proximal end33262and a second thickness a at a distal end33264thereof. In various instances, the first thickness A can range from 0.03 inches to 0.035 inches, while the second thickness a can range from 0.01 inches to 0.015 inches, for example. The first thickness A is larger than the second thickness to provide an increased strength to the reinforced anvil33200at the pivot joint formed about projection33210, for example. The reinforced anvil33200comprises a tissue-compressing surface. The tissue-compressing surface has a curved topography, wherein the distance between the tissue-compressing surface and a tissue-supporting surface of the cartridge33300is smaller at a point closer to the pivot joint about projection33210. The curved topography prevents patient tissue from becoming trapped and/or pinched between the reinforced anvil33200and the cartridge33300and/or the channel33100, for example. Welding the anvil plate33260to the anvil33250allows for the reinforced anvil33200to have an increased stiffness along the elongate slot33220of the anvil33250where substantial loads are applied by the firing member33400in addition to the portion of the anvil33250surrounding the projection33210. Such an increase in stiffness improves tissue manipulation and/or tissue clamping loads, for example. FIG.154depicts an assembly comprised of a cartridge34300and a channel34100. Such an assembly is configured to be replacably coupled to an elongate shaft of a surgical instrument distal to an articulation joint. In an effort to, for example, form a more rigid, disposable assembly, the assembly comprises an interlock system molded into the walls of the channel34100and the cartridge34300. The channel34100comprises a base34120with an elongate slot34110defined therein for receiving a portion of a firing member. The channel34100further comprises a pair of sidewalls34130extending from the base34120. A notch34150is defined in the sidewall34130. As described in greater detail throughout, the cartridge34300is configured to be seated in the channel34100. The cartridge34300comprises a plurality of staples removably positioned within staple cavities, a longitudinal slot34310extending from a proximal end toward a distal end of the cartridge34300, and a wedge sled34600configured to motivate the staples out of the respective staple cavities as the wedge sled34600translates through the longitudinal slot34310during a firing stroke. The cartridge34300further comprises a projection34350configured to be received within the notch34150when the cartridge34300is fully seated in the channel34100. A portion of a cartridge deck34320is configured to rest upon a top portion34140of the channel sidewall34130. While the cartridge is described as having a projection and the channel is described as having a notch, any suitable attachment mechanism or combination of attachment mechanisms are envisioned to releasably secure the cartridge in the channel. When the wedge sled34600is inserted into a proximal end of the cartridge34300, the cartridge34300is pushed laterally, causing the projection34350to nest within the notch34150of the channel34100. Such an interlocking engagement enables the channel34100to provide additional support to the cartridge deck34320and cartridge body than from the base34120alone. Lateral motivation of the cartridge34300diverts a tissue compression load from the cartridge deck34320into the sidewalls34130of the channel34100rather than allowing the tissue compression load to be transmitted through the body of the cartridge alone. Similar to the reinforced anvil33200shown inFIGS.151-154, the channel34100can be reinforced with a channel cap that bridges, or crosses, at least partially over top of the elongate slot34110. The base34120of the channel34100can range in thickness from 0.025 inches to 0.035 inches, for example. A channel cap with a thickness of between 0.01 inches and 0.015 inches, for example, can be welded to the base34120of the channel34100. The addition of the channel cap allows for a more robust cartridge and channel assembly. Various aspects of the present disclosure are directed to methods, devices, and systems for sealing tissue using a combination of energy and stapling modalities. The hybrid approach improves upon, and compensates for, the shortcomings of using the energy and stapling modalities separately. Referring now toFIG.155, a surgical instrument60000is configured to seal tissue using a combination of energy and stapling modalities or phases. In certain instances, is also configured to cut the tissue. The surgical instrument60000is similar in many respects to other surgical instruments (e.g. surgical instrument1000) described elsewhere herein, which are not repeated herein in the same level of detail for brevity. The surgical instrument60000includes an end effector60002, an articulation assembly60008, a shaft assembly60004, and a housing assembly60006. In the illustrated example, the articulation assembly60008permits the end effector60002to be articulated about a central longitudinal axis60005relative to the shaft assembly60006. In the illustrated example, the housing assembly60006is in the form of a handle that includes a trigger60010movable relative to a handle portion60012to effect a motion at the end effector60002. In other examples, however, the housing assembly60006can be incorporated into a robotic system. It will be understood that the various unique and novel arrangements of the various forms of the surgical instruments disclosed herein may also be effectively employed in connection with robotically-controlled surgical systems. Thus, the term “housing” may also encompass a housing or similar portion of a robotic system that houses or otherwise operably supports at least one drive system that is configured to generate and apply at least one control motion which could be used to actuate shaft assemblies disclosed herein and their respective equivalents. For example, the surgical instruments disclosed herein may be employed with various robotic systems, instruments, components and methods disclosed in U.S. patent application Ser. No. 13/118,241, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, now U.S. Patent Application Publication No. US 2012/0298719. U.S. patent application Ser. No. 13/118,241, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, now U.S. Patent Application Publication No. US 2012/0298719, is incorporated by reference herein in its entirety. In certain aspects, the housing assembly60006is detachably couplable to an interchangeable assembly that includes the shaft assembly60004, the articulation assembly60008, and the end effector60002, for example. Referring toFIG.156-162, the end effector60002extends distally from the articulation assembly60008, and includes an anvil60020and a cartridge support channel60040configured to accommodate a cartridge60030. In the illustrated example, the anvil60020defines a first jaw, while the support channel60040and the cartridge60030define a second jaw. At least one of the first jaw and the second jaw is movable relative to the other jaw to grasp tissue therebetween. In the illustrated example, rotation of a drive member, which can be in the form of a drive screw, causes a firing member, which can be in the form of an I-beam764, to move distally to pivot the anvil60020toward the cartridge60030in a closure motion to grasp tissue therebetween. Further rotation of the drive member causes of the I-beam764to engage and motivate a sled, in a firing motion, to deploy staples60033(FIG.159) from the anvil60020into the grasped tissue. The staples are generally stored in rows of staple cavities60031,60032extending longitudinally on opposite sides of a longitudinal slot60035defined in a cartridge body60039of the cartridge60030. The sled is configured to deploy the staples60033by pushing upward staple drivers in the rows of staple cavities60031,60032. Upward motion of the staple drivers deploys the staples60033from the rows of staple cavities60031,60032into the tissue. Staple legs of the staples60033are then deformed by corresponding rows of anvil pockets60021,60022(FIG.162) on opposite sides of a longitudinal slot60025defined in an anvil plate60024of the anvil60020. Referring primarily toFIG.163, a control circuit760may be programmed to control one or more functions of the surgical instrument750such as, for example, closure of the end effector60002, activation of the at least one electrode, and/or firing the cartridge60030. The control circuit760, in some examples, may comprise one or more microcontrollers, microprocessors, or other suitable processors for executing instructions that cause the processor or processors to control the one or more functions of the surgical instrument60000. In one aspect, a timer/counter781provides an output signal, such as the elapsed time or a digital count, to the control circuit760. The timer/counter781may be configured to measure elapsed time, count external events, or time external events. The control circuit760may generate a motor set point signal772. The motor set point signal772may be provided to a motor controller758. The motor controller758may comprise one or more circuits configured to provide a motor drive signal774to the motor754to drive a motor754as described herein. In some examples, the motor754may be a brushed DC electric motor. For example, the velocity of the motor754may be proportional to the motor drive signal774. In some examples, the motor754may be a brushless DC electric motor and the motor drive signal774may comprise a PWM signal provided to one or more stator windings of the motor754. Also, in some examples, the motor controller758may be omitted, and the control circuit760may generate the motor drive signal774directly. The motor754may receive power from an energy source762. The energy source762may be or include a battery, a super capacitor, or any other suitable energy source. The motor754may be mechanically coupled to the drive member751via a transmission756. The transmission756may include one or more gears or other linkage components to couple the motor754to the drive member751. In certain instances, a current sensor786can be employed to measure the current drawn by the motor754. The force required to advance the drive member751corresponds to the current drawn by the motor754. The force is converted to a digital signal and provided to the control circuit760. The current drawn by the motor754can represent tissue compression. Referring toFIG.164, a schematic of a control circuit760is depicted. According to the non-limiting aspect, the control circuit760can include a microcontroller comprising one or more processors68002(e.g., microprocessor, microcontroller) coupled to at least one memory circuit68008. The memory circuit68008can be configured to store machine-executable instructions that, when executed by the processor68002, can cause the processor68002to execute machine instructions to implement the various processes described herein. The processor68002can be any one of a number of single-core or multicore processors known in the art. Alternatively and/or additionally, the microcontroller can include a logic board, such as a Field Programmable Gate Array, for example. The memory circuit8008can comprise volatile and non-volatile storage media. The processor68002may include an instruction processing unit68004and an arithmetic unit68006. The instruction processing unit68004can be configured to receive instructions from the memory circuit68008of this disclosure. The control circuit760may employ a position sensor784to determine the position of the I-beam764. Position information is provided to a processor68002of the control circuit760, which can be programmed or configured to determine the position of the I-beam764based on the position information. In one aspect, the position information is indicative of the rotational position of the drive member751, and the processor68002is configured to calculate the positon of the I-beam764based on the rotational position of the drive member751. A display711displays a variety of operating conditions of the surgical instrument60000and may include touch screen functionality for data input. Information displayed on the display711may be overlaid with images acquired via imaging modules. The control circuit760may be in communication with one or more sensors788. The sensors788may be positioned on the end effector752and adapted to operate with the surgical instrument750to measure the various derived parameters such as gap distance versus time, tissue compression versus time, and anvil strain versus time. The sensors788may comprise a magnetic sensor, a magnetic field sensor, a strain gauge, a pressure sensor, a force sensor, an inductive sensor such as an eddy current sensor, a resistive sensor, a capacitive sensor, an optical sensor, and/or any other suitable sensor for measuring one or more parameters of the end effector752. In one aspect, sensors788may be implemented as a limit switch, electromechanical device, solid-state switches, Hall-effect devices, MR devices, GMR devices, magnetometers, among others. In other implementations, the sensors788may be solid-state switches that operate under the influence of light, such as optical sensors, IR sensors, ultraviolet sensors, among others. Still, the switches may be solid-state devices such as transistors (e.g., FET, junction FET, MOSFET, bipolar, and the like). In other implementations, the sensors788may include electrical conductorless switches, ultrasonic switches, accelerometers, and inertial sensors, among others. The sensors788may include one or more sensors. The control circuit760can be configured to simulate the response of the actual system of the instrument in the software of a controller. The drive member751can move one or more elements in the end effector752at or near a target velocity. The surgical instrument750can include a feedback controller, which can be one of any feedback controllers, including, but not limited to a PID, a state feedback, LQR, and/or an adaptive controller, for example. The surgical instrument750can include a power source to convert the signal from the feedback controller into a physical input such as case voltage, PWM voltage, frequency modulated voltage, current, torque, and/or force, for example. In addition to stapling tissue grasped between the anvil60020and the cartridge60030, the surgical instrument60000is further configured to apply an RF energy treatment to the tissue. An RF energy source794(FIG.163) is coupled to the end effector60002. As illustrated inFIG.162, the anvil60020includes a first electrode assembly60026on a first side of the longitudinal slot60025, and a second electrode assembly60027on a second side of the longitudinal slot60025opposite the first side. The electrode assemblies60026,60027can be separately, or commonly, connected to the RF energy source, and are configured to deliver RF energy to the tissue separately, or simultaneously. In the illustrated example, the first electrode assembly60026includes three segmented electrodes60026a,60026b,60026carranged in a first row on the first side of the longitudinal slot60025. Likewise, the second electrode assembly60027includes three segmented electrodes60027a,60027b,60027carranged in a second row on the second side of the longitudinal slot60025. It is, however, understood that the number of segmented electrodes in the anvil60020can be varied to accommodate various applications, for example. The segmented electrodes60026a-cand the segmented electrodes60027a-ccan be separately, or simultaneously, activated to deliver an RF energy treatment to the tissue in accordance with one or more RF energy algorithms, as discussed in greater detail below. In the illustrated example, the first electrode assembly60026is stepped up from the row of staple cavity60021. Likewise, the second electrode assembly60027is stepped up from the row of staple cavity60022. In various aspects, the segmented electrodes60026a-cand/or the segmented electrodes60027a-ccomprise the same, or substantially the same, height. In other examples, the segmented electrodes60026a-cand/or the segmented electrodes60027a-ccomprise different heights. In one arrangement, the segmented electrodes60026a-cand/or the segmented electrodes60027a-care arranged such that their heights gradually decrease from the most distal to the most proximal. In another arrangement, the segmented electrodes60026a-cand/or the segmented electrodes60027a-care arranged such that their heights gradually increase from the most distal to the most proximal. Further to the above, the cartridge60030includes an asymmetric cartridge body60034which accommodates a third electrode assembly60036including a row of segmented electrodes60036a,60036b,60036c,60036d,60036e,60036fon a first side of the longitudinal slot60035. The third electrode assembly60036is configured to oppose the first electrode assembly60026of the anvil60020in a closed configuration, as illustrated inFIG.158. The cartridge60030lacks an electrode assembly on the second side of the longitudinal slot60035. Instead, the second electrode assembly60027of the anvil60020is opposed by a longitudinal step60037extending alongside the third electrode assembly60036. In certain instances, the longitudinal step60037extends in parallel, or at least substantially in parallel, with the third electrode assembly60036. Although the third electrode assembly60036is depicted with six segmented electrodes60036a-f, more or less segmented electrodes could be utilized. The segmented electrodes60036a-fcan be separately, or commonly, connected to the RF energy source794, and can be activated separately, or simultaneously. In the illustrated example, the electrode assemblies60026,60027define source electrodes, while the third electrode assembly60036defines a return electrode such that bipolar RF energy is configured to flow from the electrode assemblies60026,60027to the third electrode assembly60036. In other examples, however, the third electrode assembly60036can be configured as a source electrode, and one or both of the electrode assemblies60026,60027can be configured as return electrodes. Further to the above, the segmented electrodes60036a-fof the third electrode assembly60036are arranged in a longitudinal row, and are spaced apart from one another. The third electrode assembly60036further includes insulators60039a-edisposed in spaces between the segmented electrodes60036a-falong the longitudinal row, as best illustrated inFIG.159. In one example, the insulators60039a-ecomprise a uniform length and/or shape. In other examples, the insulators60039a-ecomprise different lengths and/or shapes. Referring primarily toFIGS.160and161, a support wall60048extends between and separates, or at least partially separates, the third electrode assembly60036and the row of staple cavities60031. The third electrode assembly60036and the support wall60048are stepped up from the row of staple cavities60031on the first side of the longitudinal slot60035. Likewise, the longitudinal step60037is stepped up from the row of staple cavities60032on the second side of the longitudinal slot60035. The longitudinal step60037and third electrode assembly60036cooperatively define an interior tissue sealing zone stepped up from exterior tissue stapling zones defined by the rows of staple cavities60031,60032defined on opposite sides of the interior tissue sealing zone. In the illustrated example, the longitudinal step60037and third electrode assembly60036define, or at least partially define, opposite side walls of the longitudinal slot60035. The I-beam764is configured to pass between the longitudinal step60037and third electrode assembly60036in a firing motion of the surgical instrument60000. FIGS.160and161are a close-up view of the cartridge60030illustrating an example composition of the third electrode assembly60036. A flex circuit60041extends longitudinally behind the segmented electrodes60036a-fand insulators60039a-e. The flex circuit60041is positioned against the cartridge deck60047. In the illustrated example, the segmented electrodes60036a-fare electrically connected to the flex circuit60041via passive switches, current limiting elements, energy-sensitive resistance elements, or locally-adjustable resistance elements, which can be in the form of positive temperature coefficient (PTC) segments60042a-f. In other examples, the segmented electrodes60036a-fcan be directly connected to the flex circuit60041. In any event, the flex circuit60041is configured to connect the segmented electrodes60036a-fto the energy source794. In the illustrated example, the segmented electrodes60036a-fare separately connected in series with corresponding PTC segments60042a-f, respectively, as illustrated inFIG.173. In other words, there are an equal number of segmented electrodes and PTC segments. In other examples, however, two or more segmented electrodes can be connected to one PTC segment. In various aspects, the insulators60039a-eextend in gaps between the segmented electrodes60036a-f, and comprise the same, or at least substantially the same, height as the segmented electrodes60036a-fpermitting a uniform, or at least substantially uniform, tissue contacting surface along the tissue sealing zone defined by the third electrode assembly60036. Alternatively, as best illustrated inFIG.160, the segmented electrodes60036a-fand the insulators60039a-emay comprise different heights. The height disparity may allow the segmented electrodes60036a-fto act as conductive tissue gripping features. In the illustrated example, the insulator60039eextends longitudinally between the segmented electrode60036fand the segmented electrode60036e, and extends vertically to a first height slightly lesser than second and third heights of the segmented electrode60036fand the segmented electrode60036e. In other examples, the second and third heights are greater than the first height. In other examples, the first, second, and third heights are the same, or at least substantially the same. In various aspects, the segmented electrodes60036a-fcomprise a uniform, or at least substantially uniform, height. In other examples, the segmented electrodes60036a-fcomprise different heights. In one arrangement, the segmented electrodes60036a-fare arranged such that their heights gradually decrease from the most distal (segmented electrode60036f) to the most proximal (segmented electrode60036a). In another arrangement, the segmented electrodes60036a-fare arranged such that their heights gradually increase from the most distal (segmented electrode60036f) to the most proximal (segmented electrode60036a). In various aspects, the third electrode assembly60036can be secured to the cartridge body60039via posts60043extending through holes in third electrode assembly60036. As illustrated inFIG.159, in certain examples, the holes are defined in the insulators60039a-e. The posts60043can also function as heat stakes, for example. Additionally, or alternatively, the third electrode assembly60036can be secured to the cartridge body60039using any suitable locking, or mating, features, for example. In various aspects, the longitudinal step60037and the third electrode assembly60036comprise the same, or at least substantially the same, height. In other examples, the longitudinal step60037and the third electrode assembly60036comprise different heights. As illustrated inFIG.158, the anvil60020and the cartridge60030cooperatively define a tissue sealing gap60044including a first gap portion60044adefined between the first electrode assembly60026and the third electrode assembly60036, and a second gap portion60044bdefined between the second electrode assembly60027and the longitudinal step60037. In various aspects, the gap portions60044a,60044bcomprise the same, or at least substantially the same, size and/or height. In other aspects, the gap portions60044a,60044bcomprise different sizes and/or heights. Further to the above, the anvil60020and the cartridge60030cooperatively define a tissue-stapling gap60045therebetween. The tissue stapling gap60045includes a first gap portion60045adefined between the row of staple pockets60021and the row of staple cavities60031, and a second gap portion60045bdefined between the row of staple pockets60022and the row of staple cavities60032. The tissue sealing gap60044extends between the first gap portion60045aand the second gap portion60045b. In the illustrated example, the tissue sealing gap60044comprises a different height than the tissue stapling gap60045. For effective tissue sealing, the tissue sealing gap60044comprises a height selected from a range of about 0.005″ to about 0.02″, a range of about 0.008″ to about 0.018″, or a range of about 0.009″ to about 0.011″, for example. For effective tissue stapling, the tissue stapling gap60045comprises a height selected from a range of about 0.04″ to about 0.08″, a range of about 0.05″ to about 0.07″, or a range of about 0.055″ to about 0.065. In at least one example, the anvil60020and the cartridge60030cooperate to define a tissue sealing gap60044and a tissue stapling gap60045therebetween, wherein the tissue sealing gap comprises a height of about 0.01″, and the tissue stapling gap comprises a height of about 0.06″. In various aspects, as best illustrated inFIG.160, the rows of staple cavities60031,60032include pocket extenders60046that protrude from a cartridge deck60047of the cartridge60030. The pocket extenders60046ensure a proper deployment of the staples60033into tissue positioned against the cartridge deck60047. In certain examples, the tissue sealing gap60044is raised above the pocket extenders60046. In such examples, the longitudinal step60037and/or the third electrode assembly60036comprise a height, or heights, greater than that of the pocket extenders60046, for example. In various aspects, as best illustrated inFIG.160, the longitudinal step60037and the support wall60048include distal ramps60037a,60048athat facilitate insertion of the cartridge60030beneath a target tissue. The distal ramps60037a,60048agradually protrude from the cartridge deck60047toward top edges that are coplanar, or at least substantially coplanar, with tissue contacting surfaces of the longitudinal step60037and the third electrode assembly30036, for example. Referring primarily toFIG.158, the end effector60002is shown in a closed configuration suitable for application of a therapeutic energy treatment to a tissue portion between the electrode assemblies60026,60027and the third electrode assembly60036and the longitudinal step60037, and application of a tissue stapling treatment to tissue portions between rows of staple pockets60021,60022and rows of staple cavities60031,60032. In the closed configuration, a tissue sealing centerline is defined through the tissue sealing gap60044, and a tissue stapling center line is defined through the tissue stapling gap60045, wherein the tissue sealing centerline is higher than the tissue stapling centerline. In other words, the tissue sealing centerline is further away from the cartridge deck60047than the tissue stapling centerline. In the illustrated example, the tissue sealing gap60044is higher, or further away from the cartridge deck60047, than the tissue stapling centerline. In other configurations of the end effector60002, the tissue sealing centerline and the tissue stapling centerline are collinear. In various aspects, the tissue sealing centerline is equidistant from the first electrode assembly60026and the third electrode assembly60036, and/or equidistant from the second electrode assembly60027and the longitudinal step60037. In various aspects, the tissue stapling centerline is equidistant from the first row of staple cavities60021and the first row of staple cavities60031, and/or equidistant from the second row of staple cavities60022and the second row of staple cavities60032. In various aspects, the RF energy device794, which is configured to supply RF energy to the end effector60002, can be in the form of a generator such as, for example, generators800,900, which are described in greater detail below in connection withFIGS.165,166. In various aspects, the RF energy device794is electrically coupled to the electrode assemblies60026,60027,60036, and the control circuit760is configured to cause the RF energy source794to selectively switch one or more of the segmented electrodes of the electrode assemblies60026,60027,60036between an active mode and an inactive mode. In certain instances, one or more switching mechanisms can be employed to transition one or more of the segmented electrodes of the electrode assemblies60026,60027,60036between the active mode and inactive mode. In the active mode, the segmented electrodes of electrode assemblies60026,60027,60036can be utilized as source electrodes or return electrodes, depending on polarity, to implement various tissue sealing algorithms defined by the control circuit760, for example. In various aspects, the control circuit760may cause the RF energy source794to adaptively alternate, or switch, between an opposing bipolar energy mode and an offset bipolar energy mode. In the opposing bipolar energy mode the control circuit760is configured to cause the RF energy source794to pass a first therapeutic signal between the first electrode assembly60026and the third electrode assembly60036. In the offset bipolar energy mode, the control circuit760is configured to cause the RF energy source794to pass a second therapeutic signal between the second electrode assembly60027and the third electrode assembly60036. The cartridge60030, on one side of the longitudinal slot60035, includes the longitudinal step60037which is configured to cooperate with the second electrode assembly60027of the anvil60020to achieve a tissue compression suitable for energy sealing, but does not act as a return/source electrode. Alternating between the opposing energy mode and the offset energy mode permits a proper sealing of tissue in the second gap portion60044bof the tissue sealing gap60044where an electrode assembly is lacking due to the presence of the longitudinal step60037. In various aspects, as described in greater detail elsewhere herein, the longitudinal step60037includes a cavity60049therein configured to accommodate a driver support that resists driver roll. The longitudinal step60037permits the driver support to be extended above the cartridge deck60047to resist driver roll. In various aspects, the control circuit760may cause the RF energy source794to adaptively alternate, or switch, between the opposing bipolar energy mode and the offset bipolar energy mode based on a tissue parameter, or condition, such as, for example, tissue impedance.FIG.167is a logic flow diagram of a process60160depicting a control program or a logic configuration for sealing tissue grasped by an end effector by alternating, or switching, between the opposing energy mode and the offset energy mode. In certain instances, the process60160can be implemented by the surgical instrument60000, for example. In certain instances, the memory68008stores program instructions that, when executed by the processor68002, cause the processor68002to perform one or more aspects of the process60160. The process60160includes monitoring60161a tissue parameter of a tissue grasped by the end effector60002. In certain examples, the tissue parameter is a tissue compression. The control circuit760may monitor60161the tissue compression based on sensor signals from one or more sensors788. If60162the tissue parameter indicates suitable energy sealing conditions, the process60160activates60163one of the opposing energy mode and the offset energy mode. To determine whether the tissue parameter is indicative of suitable energy sealing conditions, the control circuit760may, for example, compare detected values of the tissue parameter to a predetermined threshold indicative of suitable energy sealing conditions, which can be stored in a storage medium accessible by the processor68002such as, for example, the memory68008. Following detection of a tissue parameter indicative of suitable energy sealing conditions, only the opposing energy mode is activated60163, while the offset energy mode remains inactive. In the opposing energy mode, the control circuit760may activate the electrode assemblies60026,60036, while the electrode assembly60027remains inactive. The process60160further includes monitoring tissue impedance60164to determine when to alternate, or switch, between the opposing energy mode and the offset energy mode. As described elsewhere herein in greater detail, tissue impedance of a tissue portion can be detected, for example by a control circuit760, by causing a sub-therapeutic signal to be passed through the tissue portion, receiving measurements from a voltage sensing circuit924and the current sensing circuit914, and dividing the measurements from the voltage sensing circuit924, by the corresponding measurements from the current sensing circuit914, for example. In the illustrated example, if60165a tissue impedance equal to, or beyond, a predetermined threshold is detected, the process60160switches60166from the opposing energy mode to the offset energy mode. To switch to the offset energy mode, the control circuit760may deactivate the electrode assembly60026, and activate the electrode assembly60027. In other instances, the offset energy mode is activated before activation of the opposing energy mode, and deactivated with, or after, activation of the opposing energy mode. Generator Hardware FIG.165is a simplified block diagram of a generator800configured to provide inductorless tuning, among other benefits. Additional details of the generator800are described in U.S. Pat. No. 9,060,775, titled SURGICAL GENERATOR FOR ULTRASONIC AND ELECTROSURGICAL DEVICES, which issued on Jun. 23, 2015, which is herein incorporated by reference in its entirety. The generator800may comprise a patient isolated stage802in communication with a non-isolated stage804via a power transformer806. A secondary winding808of the power transformer806is contained in the isolated stage802and may comprise a tapped configuration (e.g., a center-tapped or a non-center-tapped configuration) to define drive signal outputs810a,810b,810cfor delivering drive signals to different surgical instruments, such as, for example, an ultrasonic surgical instrument, an RF electrosurgical instrument, and a multifunction surgical instrument which includes ultrasonic and RF energy modes that can be delivered alone or simultaneously. In particular, drive signal outputs810a,810cmay output an ultrasonic drive signal (e.g., a 420V root-mean-square (RMS) drive signal) to an ultrasonic surgical instrument, and drive signal outputs810b,810cmay output an RF electrosurgical drive signal (e.g., a 100V RMS drive signal) to an RF electrosurgical instrument (e.g. surgical instrument60000), with the drive signal output810bcorresponding to the center tap of the power transformer806. It will be appreciated that the electrosurgical signal, provided to the surgical instrument60000, may be either a therapeutic or sub-therapeutic level signal where the sub-therapeutic signal can be used, for example, to monitor tissue or instrument conditions and provide feedback to the generator800. In certain instances, a sub-therapeutic signal can be employed, for example, to detect an impedance of a tissue grasped by the end effector60002. The non-isolated stage804may comprise a power amplifier812having an output connected to a primary winding814of the power transformer806. In certain forms, the power amplifier812may comprise a push-pull amplifier. For example, the non-isolated stage804may further comprise a logic device816for supplying a digital output to a digital-to-analog converter (DAC) circuit818, which in turn supplies a corresponding analog signal to an input of the power amplifier812. In certain forms, the logic device816may comprise a programmable gate array (PGA), a FPGA, programmable logic device (PLD), among other logic circuits, for example. The logic device816, by virtue of controlling the input of the power amplifier812via the DAC circuit818, may therefore control any of a number of parameters (e.g., frequency, waveform shape, waveform amplitude) of drive signals appearing at the drive signal outputs810a,810b,810c. In certain forms and as discussed below, the logic device816, in conjunction with a processor (e.g., a DSP discussed below), may implement a number of DSP-based and/or other control algorithms to control parameters of the drive signals output by the generator800. Power may be supplied to a power rail of the power amplifier812by a switch-mode regulator820, e.g., a power converter. In certain forms, the switch-mode regulator820may comprise an adjustable buck regulator, for example. The non-isolated stage804may further comprise a first processor822, which in one form may comprise a DSP processor such as an Analog Devices ADSP-21469 SHARC DSP, available from Analog Devices, Norwood, Mass., for example, although in various forms any suitable processor may be employed. In certain forms the DSP processor822may control the operation of the switch-mode regulator820responsive to voltage feedback data received from the power amplifier812by the DSP processor822via an ADC circuit824. In one form, for example, the DSP processor822may receive as input, via the ADC circuit824, the waveform envelope of a signal (e.g., an RF signal) being amplified by the power amplifier812. The DSP processor822may then control the switch-mode regulator820(e.g., via a PWM output) such that the rail voltage supplied to the power amplifier812tracks the waveform envelope of the amplified signal. By dynamically modulating the rail voltage of the power amplifier812based on the waveform envelope, the efficiency of the power amplifier812may be significantly improved relative to a fixed rail voltage amplifier schemes. In certain forms, the logic device816, in conjunction with the DSP processor822, may implement a digital synthesis circuit such as a direct digital synthesizer control scheme to control the waveform shape, frequency, and/or amplitude of drive signals output by the generator800. In one form, for example, the logic device816may implement a DDS control algorithm by recalling waveform samples stored in a dynamically updated lookup table (LUT), such as a RAM LUT, which may be embedded in an FPGA. This control algorithm is particularly useful for ultrasonic applications in which an ultrasonic transducer, such as an ultrasonic transducer, may be driven by a clean sinusoidal current at its resonant frequency. Because other frequencies may excite parasitic resonances, minimizing or reducing the total distortion of the motional branch current may correspondingly minimize or reduce undesirable resonance effects. Because the waveform shape of a drive signal output by the generator800is impacted by various sources of distortion present in the output drive circuit (e.g., the power transformer806, the power amplifier812), voltage and current feedback data based on the drive signal may be input into an algorithm, such as an error control algorithm implemented by the DSP processor822, which compensates for distortion by suitably pre-distorting or modifying the waveform samples stored in the LUT on a dynamic, ongoing basis (e.g., in real time). In one form, the amount or degree of pre-distortion applied to the LUT samples may be based on the error between a computed motional branch current and a desired current waveform shape, with the error being determined on a sample-by-sample basis. In this way, the pre-distorted LUT samples, when processed through the drive circuit, may result in a motional branch drive signal having the desired waveform shape (e.g., sinusoidal) for optimally driving the ultrasonic transducer. In such forms, the LUT waveform samples will therefore not represent the desired waveform shape of the drive signal, but rather the waveform shape that is required to ultimately produce the desired waveform shape of the motional branch drive signal when distortion effects are taken into account. The non-isolated stage804may further comprise a first ADC circuit826and a second ADC circuit828coupled to the output of the power transformer806via respective isolation transformers830,832for respectively sampling the voltage and current of drive signals output by the generator800. In certain forms, the ADC circuits826,828may be configured to sample at high speeds (e.g., 80 mega samples per second (MSPS)) to enable oversampling of the drive signals. In one form, for example, the sampling speed of the ADC circuits826,828may enable approximately 200× (depending on frequency) oversampling of the drive signals. In certain forms, the sampling operations of the ADC circuit826,828may be performed by a single ADC circuit receiving input voltage and current signals via a two-way multiplexer. The use of high-speed sampling in forms of the generator800may enable, among other things, calculation of the complex current flowing through the motional branch (which may be used in certain forms to implement DDS-based waveform shape control described above), accurate digital filtering of the sampled signals, and calculation of real power consumption with a high degree of precision. Voltage and current feedback data output by the ADC circuits826,828may be received and processed (e.g., first-in-first-out (FIFO) buffer, multiplexer) by the logic device816and stored in data memory for subsequent retrieval by, for example, the DSP processor822. As noted above, voltage and current feedback data may be used as input to an algorithm for pre-distorting or modifying LUT waveform samples on a dynamic and ongoing basis. In certain forms, this may require each stored voltage and current feedback data pair to be indexed based on, or otherwise associated with, a corresponding LUT sample that was output by the logic device816when the voltage and current feedback data pair was acquired. Synchronization of the LUT samples and the voltage and current feedback data in this manner contributes to the correct timing and stability of the pre-distortion algorithm. In certain forms, the voltage and current feedback data may be used to control the frequency and/or amplitude (e.g., current amplitude) of the drive signals. In one form, for example, voltage and current feedback data may be used to determine impedance phase. The frequency of the drive signal may then be controlled to minimize or reduce the difference between the determined impedance phase and an impedance phase setpoint (e.g., 0°), thereby minimizing or reducing the effects of harmonic distortion and correspondingly enhancing impedance phase measurement accuracy. The determination of phase impedance and a frequency control signal may be implemented in the DSP processor822, for example, with the frequency control signal being supplied as input to a DDS control algorithm implemented by the logic device816. In another form, for example, the current feedback data may be monitored in order to maintain the current amplitude of the drive signal at a current amplitude setpoint. The current amplitude setpoint may be specified directly or determined indirectly based on specified voltage amplitude and power setpoints. In certain forms, control of the current amplitude may be implemented by control algorithm, such as, for example, a proportional-integral-derivative (PID) control algorithm, in the DSP processor822. Variables controlled by the control algorithm to suitably control the current amplitude of the drive signal may include, for example, the scaling of the LUT waveform samples stored in the logic device816and/or the full-scale output voltage of the DAC circuit818(which supplies the input to the power amplifier812) via a DAC circuit834. The non-isolated stage804may further comprise a second processor836for providing, among other things user interface (UI) functionality. In one form, the UI processor836may comprise an Atmel AT91SAM9263 processor having an ARM 926EJ-S core, available from Atmel Corporation, San Jose, Calif., for example. Examples of UI functionality supported by the UI processor836may include audible and visual user feedback, communication with peripheral devices (e.g., via a USB interface), communication with a foot switch, communication with an input device (e.g., a touch screen display) and communication with an output device (e.g., a speaker). The UI processor836may communicate with the DSP processor822and the logic device816(e.g., via SPI buses). Although the UI processor836may primarily support UI functionality, it may also coordinate with the DSP processor822to implement hazard mitigation in certain forms. For example, the UI processor836may be programmed to monitor various aspects of user input and/or other inputs (e.g., touch screen inputs, foot switch inputs, temperature sensor inputs) and may disable the drive output of the generator800when an erroneous condition is detected. In certain forms, both the DSP processor822and the UI processor836, for example, may determine and monitor the operating state of the generator800. For the DSP processor822, the operating state of the generator800may dictate, for example, which control and/or diagnostic processes are implemented by the DSP processor822. For the UI processor836, the operating state of the generator800may dictate, for example, which elements of a UI (e.g., display screens, sounds) are presented to a user. The respective DSP and UI processors822,836may independently maintain the current operating state of the generator800and recognize and evaluate possible transitions out of the current operating state. The DSP processor822may function as the master in this relationship and determine when transitions between operating states are to occur. The UI processor836may be aware of valid transitions between operating states and may confirm if a particular transition is appropriate. For example, when the DSP processor822instructs the UI processor836to transition to a specific state, the UI processor836may verify that requested transition is valid. In the event that a requested transition between states is determined to be invalid by the UI processor836, the UI processor836may cause the generator800to enter a failure mode. The non-isolated stage804may further comprise a controller838for monitoring input devices (e.g., a capacitive touch sensor used for turning the generator800on and off, a capacitive touch screen). In certain forms, the controller838may comprise at least one processor and/or other controller device in communication with the UI processor836. In one form, for example, the controller838may comprise a processor (e.g., a Meg168 8-bit controller available from Atmel) configured to monitor user input provided via one or more capacitive touch sensors. In one form, the controller838may comprise a touch screen controller (e.g., a QT5480 touch screen controller available from Atmel) to control and manage the acquisition of touch data from a capacitive touch screen. In certain forms, when the generator800is in a “power off” state, the controller838may continue to receive operating power (e.g., via a line from a power supply of the generator800, such as the power supply854discussed below). In this way, the controller838may continue to monitor an input device (e.g., a capacitive touch sensor located on a front panel of the generator800) for turning the generator800on and off. When the generator800is in the power off state, the controller838may wake the power supply (e.g., enable operation of one or more DC/DC voltage converters856of the power supply854) if activation of the “on/off” input device by a user is detected. The controller838may therefore initiate a sequence for transitioning the generator800to a “power on” state. Conversely, the controller838may initiate a sequence for transitioning the generator800to the power off state if activation of the “on/off” input device is detected when the generator800is in the power on state. In certain forms, for example, the controller838may report activation of the “on/off” input device to the UI processor836, which in turn implements the necessary process sequence for transitioning the generator800to the power off state. In such forms, the controller838may have no independent ability for causing the removal of power from the generator800after its power on state has been established. In certain forms, the controller838may cause the generator800to provide audible or other sensory feedback for alerting the user that a power on or power off sequence has been initiated. Such an alert may be provided at the beginning of a power on or power off sequence and prior to the commencement of other processes associated with the sequence. In certain forms, the isolated stage802may comprise an instrument interface circuit840to, for example, provide a communication interface between a control circuit of a surgical instrument (e.g., a control circuit comprising handpiece switches) and components of the non-isolated stage804, such as, for example, the logic device816, the DSP processor822, and/or the UI processor836. The instrument interface circuit840may exchange information with components of the non-isolated stage804via a communication link that maintains a suitable degree of electrical isolation between the isolated and non-isolated stages802,804, such as, for example, an IR-based communication link. Power may be supplied to the instrument interface circuit840using, for example, a low-dropout voltage regulator powered by an isolation transformer driven from the non-isolated stage804. In one form, the instrument interface circuit840may comprise a logic circuit842(e.g., logic circuit, programmable logic circuit, PGA, FPGA, PLD) in communication with a signal conditioning circuit844. The signal conditioning circuit844may be configured to receive a periodic signal from the logic circuit842(e.g., a 2 kHz square wave) to generate a bipolar interrogation signal having an identical frequency. The interrogation signal may be generated, for example, using a bipolar current source fed by a differential amplifier. The interrogation signal may be communicated to a surgical instrument control circuit (e.g., by using a conductive pair in a cable that connects the generator800to the surgical instrument) and monitored to determine a state or configuration of the control circuit. The control circuit may comprise a number of switches, resistors, and/or diodes to modify one or more characteristics (e.g., amplitude, rectification) of the interrogation signal such that a state or configuration of the control circuit is uniquely discernable based on the one or more characteristics. In one form, for example, the signal conditioning circuit844may comprise an ADC circuit for generating samples of a voltage signal appearing across inputs of the control circuit resulting from passage of interrogation signal therethrough. The logic circuit842(or a component of the non-isolated stage804) may then determine the state or configuration of the control circuit based on the ADC circuit samples. In certain forms, the first data circuit may store information pertaining to the particular surgical instrument with which it is associated. Such information may include, for example, a model number, a serial number, a number of operations in which the surgical instrument has been used, and/or any other type of information. This information may be read by the instrument interface circuit840(e.g., by the logic circuit842), transferred to a component of the non-isolated stage804(e.g., to logic device816, DSP processor822, and/or UI processor836) for presentation to a user via an output device and/or for controlling a function or operation of the generator800. Additionally, any type of information may be communicated to the first data circuit for storage therein via the first data circuit interface846(e.g., using the logic circuit842). Such information may comprise, for example, an updated number of operations in which the surgical instrument has been used and/or dates and/or times of its usage. As discussed previously, a surgical instrument may be detachable from a handpiece (e.g., the multifunction surgical instrument may be detachable from the handpiece) to promote instrument interchangeability and/or disposability. In such cases, conventional generators may be limited in their ability to recognize particular instrument configurations being used and to optimize control and diagnostic processes accordingly. The addition of readable data circuits to surgical instruments to address this issue is problematic from a compatibility standpoint, however. For example, designing a surgical instrument to remain backwardly compatible with generators that lack the requisite data reading functionality may be impractical due to, for example, differing signal schemes, design complexity, and cost. Forms of instruments discussed herein address these concerns by using data circuits that may be implemented in existing surgical instruments economically and with minimal design changes to preserve compatibility of the surgical instruments with current generator platforms. Additionally, forms of the generator800may enable communication with instrument-based data circuits. For example, the generator800may be configured to communicate with a second data circuit contained in an instrument (e.g., the multifunction surgical instrument). In some forms, the second data circuit may be implemented in a many similar to that of the first data circuit described herein. The instrument interface circuit840may comprise a second data circuit interface848to enable this communication. In one form, the second data circuit interface848may comprise a tri-state digital interface, although other interfaces may also be used. In certain forms, the second data circuit may generally be any circuit for transmitting and/or receiving data. In one form, for example, the second data circuit may store information pertaining to the particular surgical instrument with which it is associated. Such information may include, for example, a model number, a serial number, a number of operations in which the surgical instrument has been used, and/or any other type of information. In some forms, the second data circuit may store information about the electrical and/or ultrasonic properties of an associated ultrasonic transducer, end effector, or ultrasonic drive system. For example, the first data circuit may indicate a burn-in frequency slope, as described herein. Additionally or alternatively, any type of information may be communicated to second data circuit for storage therein via the second data circuit interface848(e.g., using the logic circuit842). Such information may comprise, for example, an updated number of operations in which the instrument has been used and/or dates and/or times of its usage. In certain forms, the second data circuit may transmit data acquired by one or more sensors (e.g., an instrument-based temperature sensor). In certain forms, the second data circuit may receive data from the generator800and provide an indication to a user (e.g., a light emitting diode indication or other visible indication) based on the received data. In certain forms, the second data circuit and the second data circuit interface848may be configured such that communication between the logic circuit842and the second data circuit can be effected without the need to provide additional conductors for this purpose (e.g., dedicated conductors of a cable connecting a handpiece to the generator800). In one form, for example, information may be communicated to and from the second data circuit using a one-wire bus communication scheme implemented on existing cabling, such as one of the conductors used transmit interrogation signals from the signal conditioning circuit844to a control circuit in a handpiece. In this way, design changes or modifications to the surgical instrument that might otherwise be necessary are minimized or reduced. Moreover, because different types of communications implemented over a common physical channel can be frequency-band separated, the presence of a second data circuit may be “invisible” to generators that do not have the requisite data reading functionality, thus enabling backward compatibility of the surgical instrument. In certain forms, the isolated stage802may comprise at least one blocking capacitor850-1connected to the drive signal output810bto prevent passage of DC current to a patient. A single blocking capacitor may be required to comply with medical regulations or standards, for example. While failure in single-capacitor designs is relatively uncommon, such failure may nonetheless have negative consequences. In one form, a second blocking capacitor850-2may be provided in series with the blocking capacitor850-1, with current leakage from a point between the blocking capacitors850-1,850-2being monitored by, for example, an ADC circuit852for sampling a voltage induced by leakage current. The samples may be received by the logic circuit842, for example. Based changes in the leakage current (as indicated by the voltage samples), the generator800may determine when at least one of the blocking capacitors850-1,850-2has failed, thus providing a benefit over single-capacitor designs having a single point of failure. In certain forms, the non-isolated stage804may comprise a power supply854for delivering DC power at a suitable voltage and current. The power supply may comprise, for example, a 400 W power supply for delivering a 48 VDC system voltage. The power supply854may further comprise one or more DC/DC voltage converters856for receiving the output of the power supply to generate DC outputs at the voltages and currents required by the various components of the generator800. As discussed above in connection with the controller838, one or more of the DC/DC voltage converters856may receive an input from the controller838when activation of the “on/off” input device by a user is detected by the controller838to enable operation of, or wake, the DC/DC voltage converters856. FIG.166illustrates an example of a generator900, which is one form of the generator800(FIG.165). The generator900is configured to deliver multiple energy modalities to a surgical instrument. The generator900provides RF and ultrasonic signals for delivering energy to a surgical instrument either independently or simultaneously. The RF and ultrasonic signals may be provided alone or in combination and may be provided simultaneously. As noted above, at least one generator output can deliver multiple energy modalities (e.g., ultrasonic, bipolar or monopolar RF, irreversible and/or reversible electroporation, and/or microwave energy, among others) through a single port, and these signals can be delivered separately or simultaneously to the end effector to treat tissue. The generator900comprises a processor902coupled to a waveform generator904. The processor902and waveform generator904are configured to generate a variety of signal waveforms based on information stored in a memory coupled to the processor902, not shown for clarity of disclosure. The digital information associated with a waveform is provided to the waveform generator904which includes one or more DAC circuits to convert the digital input into an analog output. The analog output is fed to an amplifier1106for signal conditioning and amplification. The conditioned and amplified output of the amplifier906is coupled to a power transformer908. The signals are coupled across the power transformer908to the secondary side, which is in the patient isolation side. A first signal of a first energy modality is provided to the surgical instrument between the terminals labeled ENERGY1 and RETURN. A second signal of a second energy modality is coupled across a capacitor910and is provided to the surgical instrument between the terminals labeled ENERGY2 and RETURN. It will be appreciated that more than two energy modalities may be output and thus the subscript “n” may be used to designate that up to n ENERGYn terminals may be provided, where n is a positive integer greater than 1. It also will be appreciated that up to “n” return paths RETURNn may be provided without departing from the scope of the present disclosure. A first voltage sensing circuit912is coupled across the terminals labeled ENERGY1 and the RETURN path to measure the output voltage therebetween. A second voltage sensing circuit924is coupled across the terminals labeled ENERGY2 and the RETURN path to measure the output voltage therebetween. A current sensing circuit914is disposed in series with the RETURN leg of the secondary side of the power transformer908as shown to measure the output current for either energy modality. If different return paths are provided for each energy modality, then a separate current sensing circuit should be provided in each return leg. The outputs of the first and second voltage sensing circuits912,924are provided to respective isolation transformers916,922and the output of the current sensing circuit914is provided to another isolation transformer918. The outputs of the isolation transformers916,928,922in the on the primary side of the power transformer908(non-patient isolated side) are provided to a one or more ADC circuit926. The digitized output of the ADC circuit926is provided to the processor902for further processing and computation. The output voltages and output current feedback information can be employed to adjust the output voltage and current provided to the surgical instrument and to compute output impedance, among other parameters. Input/output communications between the processor902and patient isolated circuits is provided through an interface circuit920. Sensors also may be in electrical communication with the processor902by way of the interface circuit920. In one aspect, the impedance may be determined by the processor902by dividing the output of either the first voltage sensing circuit912coupled across the terminals labeled ENERGY1/RETURN or the second voltage sensing circuit924coupled across the terminals labeled ENERGY2/RETURN by the output of the current sensing circuit914disposed in series with the RETURN leg of the secondary side of the power transformer908. The outputs of the first and second voltage sensing circuits912,924are provided to separate isolations transformers916,922and the output of the current sensing circuit914is provided to another isolation transformer916. The digitized voltage and current sensing measurements from the ADC circuit926are provided the processor902for computing impedance. As an example, the first energy modality ENERGY1 may be ultrasonic energy and the second energy modality ENERGY2 may be RF energy. Nevertheless, in addition to ultrasonic and bipolar or monopolar RF energy modalities, other energy modalities include irreversible and/or reversible electroporation and/or microwave energy, among others. Also, although the example illustrated inFIG.166shows a single return path RETURN may be provided for two or more energy modalities, in other aspects, multiple return paths RETURNn may be provided for each energy modality ENERGYn. Thus, as described herein, the ultrasonic transducer impedance may be measured by dividing the output of the first voltage sensing circuit912by the current sensing circuit914and the tissue impedance may be measured by dividing the output of the second voltage sensing circuit924by the current sensing circuit914. As shown inFIG.166, the generator900comprising at least one output port can include a power transformer908with a single output and with multiple taps to provide power in the form of one or more energy modalities, such as ultrasonic, bipolar or monopolar RF, irreversible and/or reversible electroporation, and/or microwave energy, among others, for example, to the end effector depending on the type of treatment of tissue being performed. For example, the generator900can deliver energy with higher voltage and lower current to drive an ultrasonic transducer, with lower voltage and higher current to drive RF electrodes for sealing tissue, or with a coagulation waveform for spot coagulation using either monopolar or bipolar RF electrosurgical electrodes. The output waveform from the generator900can be steered, switched, or filtered to provide the frequency to the end effector of the surgical instrument. The connection of an ultrasonic transducer to the generator900output would be preferably located between the output labeled ENERGY1 and RETURN as shown inFIG.166. In one example, a connection of RF bipolar electrodes to the generator900output would be preferably located between the output labeled ENERGY2 and RETURN. In the case of monopolar output, the preferred connections would be active electrode (e.g., pencil or other probe) to the ENERGY2 output and a suitable return pad connected to the RETURN output. Additional details are disclosed in U.S. Patent Application Publication No. 2017/0086914, titled TECHNIQUES FOR OPERATING GENERATOR FOR DIGITALLY GENERATING ELECTRICAL SIGNAL WAVEFORMS AND SURGICAL INSTRUMENTS, which published on Mar. 30, 2017, which is herein incorporated by reference in its entirety. Referring toFIGS.168-170, a cartridge60130is similar in many respects to the cartridge60030. For example, the cartridge60130can also be utilized with the surgical instrument60000to seal and staple tissue. Also, the cartridge60130includes rows of staple cavities60131,60132extending on opposite sides of a longitudinal slot60135defined in a cartridge body60139, and housing staples60133. The cartridge60130also includes a third electrode assembly60136coupled to the cartridge body60139. In the illustrated example, the third electrode assembly60136includes segmented electrodes60136a-fand a flex circuit60141extending longitudinally behind the segmented electrodes, and configured to connect the segmented electrodes to the RF energy source794. The flex circuit60141is positioned against the cartridge deck60147. Sandwiched between the segmented electrodes and the flex circuit60141are passive switches, current limiting elements, energy-sensitive resistance elements, or locally-adjustable resistance elements, which can be in the form of positive temperature coefficient (PTC) segments60142. Further to the above, the third electrode assembly60136is configured to cover exposed cavities60134in the cartridge body60139, wherein the exposed cavities60134are configured to accommodate driver supports60149aof staple drivers60149. The driver supports60149aare configured to resist driver roll. The exposed cavities60134permit the driver support60149ato be extended above the cartridge deck60147to resist driver roll. Like the cartridge60030, the cartridge60130includes a longitudinal step60137—similar to the longitudinal stop60037, which are not repeated herein for brevity. The longitudinal step60137is configured to cover exposed cavities60134′ in the cartridge body60139, wherein the exposed cavities60134′ are configured to accommodate driver supports60149a′ of staple drivers60149′. The driver supports60149a′ are configured to resist driver roll. The exposed cavities60134′ permit the driver supports60149a′ to be extended above the cartridge deck60147to resist driver roll. Additional details about driver supports are disclosed elsewhere in the present disclosure, and are not repeated herein for brevity. Securing members60145a-cprotrude from a cartridge deck60147of the cartridge60130. The securing members60145a-care configured to lockingly engage the third electrode assembly60136. In the illustrated example, the securing members60145a-cdefine right-angled bracket s that are configured to matingly engage portions of the third electrode assembly60136. During assembly, insulative segments of the third electrode assembly60136are configured to snap into a locking engagement with the securing members6045a-c. FIG.171illustrates a cross-sectional view of the anvil60020ofFIG.162. In the illustrated example, the electrode assemblies60026,60027include segmented electrodes60026a-cand60027a-c, respectively. Further, Flex circuits60056,60058extend longitudinally between the segmented electrodes60026a-cand60027a-c, respectively, and an anvil deck60057. The flex circuits60056,60058are configured to connect the segmented electrodes to the RF energy source794, as illustrated inFIG.173. Sandwiched between the segmented electrodes and the flex circuits60056,60058are passive switches, current limiting elements, energy-sensitive resistance elements, or locally-adjustable resistance elements, which can be in the form of positive temperature coefficient (PTC) segments60053a-c,60054a-c. In the illustrated example, the segmented electrodes60026a-c,60027a-cof the electrode assemblies60026,60027are separately connected in series with corresponding PTC segments60053a-c,60054a-c, respectively, as illustrated inFIG.173. In other words, there are an equal number of segmented electrodes and PTC segments. In other examples, however, two or more segmented electrodes can be connected to one PTC segment. FIG.172illustrates an anvil60120similar in many respects to the anvil60020. For example, the anvil60120can also be utilized with the surgical instrument60000to seal and staple tissue. Also, the anvil60120includes rows of staple pockets60121,60122defined in an anvil deck60157, and electrode assemblies60126,60127extending on opposite sides of a longitudinal slot60125. In the illustrated example, the electrode assemblies60126,60127include segmented electrodes60126a-cand60127a-c, respectively. Furthermore, flex circuits60156,60158extend longitudinally behind the segmented electrodes60126a-cand60127a-c, respectively, and are configured to connect the segmented electrodes60126a-cand60127a-cto the RF energy source794. Further, the electrode assemblies60126,60127include passive switches, current limiting elements, energy-sensitive resistance elements, or locally-adjustable resistance elements, which can be in the form of positive temperature coefficient (PTC) segments60153a-c,60154a-c. In the illustrated example, the segmented electrodes60126a-cand60127a-care connected in series to the PTC segments60153a-c,60154a-c, respectively, but the PTC segments60153a-c,60154a-care not located directly behind the segmented electrodes60126a-cand60127a-c. Instead, the PTC segments60153a-c,60154a-care disposed at a proximal portion of the anvil60120. The flex Circuits60156,60158extend between the PTC segments60153a-c,60154a-cand the segmented electrodes60126a-cand60127a-c. In the illustrated example, each of segmented electrodes60126a-cand60127a-cis connected to a dedicated PTC segment. In other, examples, however, two or more segmented electrodes can share a PTC segment. Referring still toFIG.172, PTC segments60153a-cand the PTC segments60154a-care arranged on opposite sides of the longitudinal slot60125at a proximal portion of the anvil60120. In the illustrated example, the PTC segments60153a-cand60154a-care coupled to the anvil60120proximal to the rows of staple pockets60121,60122. In addition, the PTC segments60153a-cand60154a-care arranged in two rows. Other arrangements are contemplated by the present disclosure. FIG.173is an electrical diagram illustrating a simplified electrical layout of the electrode assemblies60036,60026,60027, in accordance with at least one aspect of the present disclosure. In the illustrated example, the segmented electrodes60036a-f,60026a-c,60027a-care separately connected to passive switches, current limiting elements, energy-sensitive resistance elements, or locally-adjustable resistance elements, which can be in the form of positive temperature coefficient (PTC) segments60042a-f,60053a-c,60054a-c, respectively. The passive switches, current limiting elements, energy-sensitive resistance elements, or locally-adjustable resistance elements, which can be in the form of positive temperature coefficient (PTC) segments60042a-f,60053a-c,60054a-c, are configured to adaptively and independently control current through their respective segmented electrodes60036a-f,60026a-c,60027a-c. In certain instances, the passive switches, current limiting elements, energy-sensitive resistance elements, or locally-adjustable resistance elements, which can be in the form of positive temperature coefficient (PTC) segments60042a-f,60053a-c,60054a-c, are configured to passively and independently deactivate, or reduce, energy flow through their respective segmented electrodes60036a-f,60026a-c,60027a-c, in response to a short circuit, for example. In the example illustrated inFIG.173, each of the electrode assemblies60026,60027,60036includes PTC segments. In other examples, however, PTC segments can be limited to any one or two of the electrode assemblies60026,60027,60036. As described in greater detail below, the PTC segments utilized with the electrode assemblies60026,60027,60036can be different in one or more aspects. In certain examples, the PTC segments can be different in transition temperatures, material composition, and/or response to short circuits. FIG.174is an electrical diagram illustrating an electrical layout of an alternative electrode assembly60060that can be implemented with one or more of the electrode assemblies60036,60026,60027. In the illustrated example, the electrode assembly60060includes segmented electrodes60060a-c. In other examples, however, the electrode assembly60060may include more, or less, than three segmented electrodes. In any event, the segmented electrodes60060a-care commonly connected to a passive switch, current limiting element, energy-sensitive resistance element, or locally-adjustable resistance element, which can be in the form of a positive temperature coefficient (PTC) segment60061. In such example, the PTC segment60061is configured to adaptively and independently control current through segmented electrodes60060a-c. In certain instances, the PTC segment60061is configured to passively and independently deactivate energy flow through the segmented electrodes60060a-cin response to a short circuit, for example. Referring primarily toFIGS.163and173, the control circuit760may cause the RF energy source794to adaptively alternate, or switch, between an opposing bipolar energy mode and an offset bipolar energy mode. In the opposing bipolar energy mode the control circuit760is configured to cause the RF energy source794to pass a first therapeutic signal between the first electrode assembly60026and the third electrode assembly60036. In the offset bipolar energy mode, the control circuit760is configured to cause the RF energy source794to pass a second therapeutic signal between the second electrode assembly60027and the third electrode assembly60036. Further to the above, in the opposing energy mode, a current pathway can be defined through the PTC segment60053a, the segmented electrode60026a, the tissue (T) (between the anvil60020and the staple cartridge60030), the segmented electrode60036a, and the PTC segment60042a, for example. When the opposing energy mode is switched to the offset energy mode, the current pathway is also switched. For example, in the offset energy mode, the current pathway can be defined through the PTC segment60054a, the segmented electrode60024a, the tissue (T), the segmented electrode60036a, and the PTC segment60042a. Furthermore, depending on the size of the segmented electrodes and circuit polarity, various other current pathways can be established. For example, current pathways can be established between the segmented electrode60026aand the segmented electrodes60036a,60036b. FIG.175is a cross-sectional view of an end effector60002′ similar in many respects to the end effector60002, which are not repeated herein for brevity. For example, the end effector60002′ can also be used with the surgical instrument6000in a similar manner to the end effector60002. Various components of the end effector60002′, which are similar to the end effector60002are removed for clarity. Unlike the end effector60002, the end effector60002′ includes an anvil60020′ that lacks the PTC segments60054a-f,60053a-f. In the illustrated example, tissue (T) is captured between an anvil60020′ and the cartridge60030′. The control circuit760then activates the electrode assemblies60026,60036to apply a tissue treatment cycle to the tissue (T) utilizing an opposing bipolar energy mode. In the illustrated example, the RF energy source794causes current to flow from the electrode assembly60026to the electrode assembly60036. Accordingly, the segmented electrodes60026b,60026cdefine source electrodes and the segmented electrodes60036d,60036e,60036fdefine return electrodes. In other examples, the RF energy source794may reverse the circuit polarity such that the segmented electrodes60026b,60026cdefine return electrodes and the segmented electrodes60036d,60036e,60036fdefine source electrodes. In any event, the tissue (T) includes a staple60033previously-deployed into the tissue. The presence of the staple60033causes a short circuit to form between the segmented electrodes60026c,60036e. As described in greater detail below, the short circuit causes the resistance of the PTC segment60042eto increase (e.g. from 5Ω to 20Ω) thereby effectively deactivating the energy flow between the segmented electrodes60026cand60036e, or at least reducing the energy flow to a sub-therapeutic level. Accordingly, the PTC segment60042eis configured to passively and independently control the current flow through the tissue (T). In certain instances, the PTC segment60042eis configured to passively deactivate the segmented electrode60036ewithout processor-based communication or control, in response to a short circuit between the segmented electrodes60026c,60036e. In the illustrated example, current is automatically diverted to adjacent segmented electrode60036d,60036f, as the resistances of the PTC segments60042d,60042fhave not been affected by the short circuit. PTC segments, in accordance with at least one aspect of the present disclosure, generally comprise a low-resistance condition at a temperature during a normal operation. However, on exposure to high temperature due to, for example, unusually large current resulting from the formation of a short circuit or excessive discharge, the PTC segments switch into an extremely high-resistance mode. Simply put, when the PTC segments are included in a circuit and an abnormal current passes through the circuit, such as in the instance of a short circuit caused by a staple60033, the resulting higher temperature condition switches the PTC segments to a higher resistance condition to decrease the current passing through the circuit to a minimal level and, thus, protect electric elements of the circuit. FIG.176is a graph60060illustrating the change in resistance (Ω) of a PTC segment in response to a change in temperature (° C.), in accordance with the at least one aspect of the present disclosure. In the illustrated example, the PTC segment comprises a transition temperature Ts, also referred to elsewhere herein as a switching temperature or a threshold temperature. In operation, a short circuit, possibly caused by the presence of a previously-fired staple60033in the tissue (T), may cause an increase in the temperature of the PTC segment. At the transition temperature Ts, the resistance (Ω) of the PTC segment increases significantly, effectively deactivating the segmented electrode affected by the short circuit, as described supra. Accordingly, the PTC segment acts as a resettable fuse for overcurrent Protection. FIG.177is another graph60065illustrating the change in resistance (Ω) of a PTC segment in response to a change in temperature (° C.), in accordance with the at least one aspect of the present disclosure. The resistance (Ω) is shown on a logarithmic scale. The resistance (Ω) of the PTC segment is generally maintained at a steady state during normal operation, but the resistance (Ω) begins to increase exponentially at the transition temperature Ts. As the temperature rises toward the transition temperature Ts, the resistance (Ω) increases slightly from a minimum resistance Rminto a higher resistance (e.g. double Rmin) at the transition temperature Ts. However, beyond the transition temperature Ts, the increase in the resistance (Ω) is exponential, effectively resulting in a deactivation of the current through the PTC segment. Referring again toFIG.175, the PTC segments60042a-fcan be configured to locally sense shorted electrical pathways, where overlap with previously-fired staples occurs, and deactivate affected segmented electrodes60036a-f,60026a-c,60027a-c, based on the same principles discussed in connection withFIGS.176and177. In the exemplification illustrated inFIG.175, the segmented electrodes60036a-fare commonly connected to the RF energy source794by individual connections originating from individual bifurcations of a common connection. As such, deactivation of the segmented electrode60036eby the PTC segment60042edoes not stop current flow to the other segmented electrodes in the electrode assembly60036. Instead, the current from the segmented electrode60026cis automatically diverted from the segmented electrode60036e, and away from the staple60033, toward the segmented electrodes60036f,60036d. In result, the segmented electrode60036eis passively and independently deactivated in response to the short circuit without processor based communication or control, while the remaining segmented electrodes of the third electrode assembly60036, which are not affected by the short circuit, uninterruptedly continue to deliver energy to the tissue to seal the tissue. FIG.178is a graph60070depicting passive and independent control of a current through a tissue portion including a staple60033between the electrode assemblies60026,60036(e.g. between the segmented electrodes60026c,60036f) during a tissue treatment cycle employing an opposing energy mode, in accordance with at least one aspect of the present disclosure. In the illustrated example, PTC segments60042c,60053fare configured to perform a passive and independent control of the current during the tissue treatment cycle. The Graph60070includes multiple graphs depicting time (t) on the X-axis vs source electrode (e.g.60026c) active status60071, return electrode (e.g. segmented electrode60036f) active status60072, power level60073, tissue impedance60074, and resistance60075of at least one of the PTC segments60042c,40053f, on the Y-axis. In the illustrated example, the control circuit760is configured to execute a tissue treatment cycle including a sub-therapeutic signal60077aand a therapeutic signal60077bapplied to a tissue grasped by the end effector60002. The control circuit760is configured to cause the RF energy source794to activate70076the return electrode, and then activate70077the source electrode. In certain instances, the RF energy source794may include one or more switching mechanisms for transitioning one or more of the segmented electrodes of the electrode assemblies60026,60027,60036between active and inactive modes, for example. Further to the above, during application of the sub-therapeutic signal60077a, the power level is maintained at a first level60078atoo low to effect a significant change (first portion70079aof the resistance line) in the resistance of the PTC segment(s) in the presence of the staple60033. However, during application of the therapeutic signal60077b, the power level is increased to a second level60078b, which begins to increase (second portion70079bof the resistance line) the resistance of the PTC segment(s) due to an increase in temperature caused by the short circuit created by the staple60033. In certain instances, the change in the resistance of the PTC segment(s) can be detected by the control circuit760by monitoring current and voltage parameters. In certain instances, if the change in resistance is greater than or equal to a predetermined threshold, the control circuit760concludes the presence of a short circuit, which can be reported to a user through the display711, for example. Furthermore, in certain instances, the control circuit760may be further to configured to shut down60080power delivery to the end effector60002at this point. If power delivery continues, the temperature of the PTC segment(s) will eventually reach the transition temperature Ts of the PTC segment(s). At such point, the resistance of the PTC segment(s) increases (third portion60079cof the resistance line) exponentially, effectively deactivating60081,60081the source and return electrodes. In various instances, PTC segments in accordance with at least one aspect of the present disclosure are ceramic PTC segments, with resistance-temperature characteristics that are attributed to the electronic properties of ceramic grain boundaries. In certain aspects, one or more of the PTC segments60042a-f,60053a-c,60054a-ccan be selected to operate as a quick-trip fuse or a slow-trip fuse in response to a short circuit, such as one caused by a previously fired staple60033, based on their temperature-resistance characteristics. FIG.179is a graph60090illustrating a PTC segment's trip response at different temperatures. The Y-axis represents current through the PTC segment, and the X-axis represents temperature of the PTC segment. In the illustrated example, a line60091is a hold-current line, which represents a maximum value of hold current at operating temperature. Hold current is a maximum current value which can be flowed in normal operation. Further, a line60092is a trip-current line, which represents a minimum current value which is necessary for PTC segment to move to high-resistance state. Hold current and trip current have temperature dependence which features decreasing current value with increasing temperature. The lines60091,60092define three distinct regions. A first region60090aidentifies where the PTC segment operates as a quick-trip fuse, a second region60090bidentifies where the PTC segment operates at a low/normal resistance, and a third region60090cidentifies where the PTC segment operates as a slow-trip fuse. Accordingly, one or more of the PTC segments60042a-f,60053a-c,60054a-ccan be selected to operate as a quick-trip fuse or a slow-trip fuse based on resistance-temperature characteristics. In certain instances, the slow-trip PTC segments comprise a higher transition temperature Ts than the fast-trip PTC segments. In one example, one or more of the PTC segments60042a-fcan be selected to operate as a quick-trip fuse, and one or more of the PTC segments60053a-c,60054a-ccan be selected to operate as a slow-trip fuse, in response to the short circuit. In at least one example, one or more of the PTC segments60042a-fmay include a first transition temperature Ts, and one or more of the PTC segments60053a-c,60054a-cmay include a second transition temperature Ts higher than the first transition temperature. In certain instances, the quick-trip fuse characteristic of the PTC segments60042a-fensure that current flow to the tissue is stopped during a short circuit. Meanwhile, the slow-trip fuse characteristic of the PTC segments60053a-c,60054a-cmay still permit current to flow through the corresponding segmented electrodes60026a-c,60027a-c. In certain instances, the electrode assemblies60026,60027are configured such that, while the slow-trip fuse of the PTC segments60053a-c,60054a-cis triggered, each of the segmented electrodes60026a-c,60027a-callows the current to flow back to the RF energy source794, or control electronics thereof (e.g. control circuit760), in an isolated manner, to allow the control electronics to detect which of the segmented electrodes60026a-c,60027a-cis associated with a PTC segment that has changed its resistance. The control circuit760may then alert a user, for example through the display711, of the portion of the end effector60002affected by the short circuit. Furthermore, the control circuit760may also adjust an ongoing tissue treatment cycle to address the detected short circuit. FIG.180is a logic flow diagram of a process60100depicting a control program or a logic configuration for detecting and addressing a short circuit during a tissue treatment cycle applied to tissue grasped by the end effector60002. In certain instances, the process60100can be implemented by the surgical instrument60000, for example. In at least one example, the process60100can be executed by the control circuit760. In certain instances, the memory68008stores program instructions that, when executed by the processor68002, cause the processor68002to perform one or more aspects of the process60100. The process60100includes monitoring60101a parameter indicative of a current returned from a source segmented electrode (e.g. the segmented electrodes60026a-c,60027a-c). The control circuit760may receive signals from a current sensor indicative of one or more current values of the returned current. The process60100detects60106a short circuit at the segmented electrode if60103a change in the monitored parameter is equal to, or beyond, a predetermined value. In certain instances, the predetermined value can be stored in a storage medium such as, for example, the memory68008. The process60100may further issue60104an alert and/or adjust60105at least one parameter of the tissue treatment cycle in response to the short circuit. FIG.181is a logic flow diagram of a process60110depicting a control program or a logic configuration for a tissue treatment cycle applied to tissue grasped by the end effector60002, in accordance with at least one aspect of the present disclosure. In certain instances, the process60110can be implemented by the surgical instrument60000, for example. The process60110is similar in many respects to the process60150. For example, the process60110can also be executed by the control circuit760. In certain instances, the memory68008stores program instructions that, when executed by the processor68002, cause the processor68002to perform one or more aspects of the process60110. The process60110includes monitoring60111a tissue parameter of a tissue grasped by the end effector60002. In certain examples, the tissue parameter is a tissue compression. The control circuit760may monitor60111the tissue compression based on sensor signals from one or more sensors788. If60112the tissue parameter indicates suitable energy sealing conditions, the process60110activates60113the offset energy mode, while the opposing energy mode remains inactive. To determine whether the tissue parameter is indicative of suitable energy sealing conditions, the control circuit760may, for example, compare detected values of the tissue parameter to a predetermined threshold indicative of suitable energy sealing conditions, which can be stored in a storage medium accessible by the processor68002such as, for example, the memory68008. In the offset energy mode, the control circuit760may activate the electrode assemblies60026,60036, while the electrode assembly60027remains inactive. The process60110further includes monitoring tissue impedance60114to determine when to switch from the offset energy mode to the opposing energy mode. As described elsewhere herein in greater detail, tissue impedance of a tissue portion can be detected, for example by a control circuit760, by causing a sub-therapeutic signal to be passed through the tissue portion, receiving measurements from a voltage sensing circuit924and the current sensing circuit914, and dividing the measurements from the voltage sensing circuit924, by the corresponding measurements from the current sensing circuit914, for example. In the illustrated example, if60114a tissue impedance equal to, or beyond, a predetermined threshold is detected, the process60110switches60115from the opposing energy mode to the offset energy mode. To switch to the offset energy mode, the control circuit760may deactivate the electrode assembly60026, and activate the electrode assembly60027. In other instances, the offset energy mode is activated before activation of the opposing energy mode, and deactivated with, or after, activation of the opposing energy mode. Further to the above, if60116a short circuit is detected, the process60110may issue an alert60117, switch to the offset energy mode60118, and/or deactivate60119the affected segmented electrodes of one or more of the electrode assemblies60026,60027,60036, for example. A short circuit can be detected, as described in greater detail in connection with the process60100, by monitoring a parameter indicative of a current returned from a source segmented electrode, for example. In certain instances, the tissue is a thick tissue such as a liver tissue, and the end effector60002is configured to grasp the liver tissue and apply a tissue treatment cycle thereto in accordance with the process60110. For example, the control circuit760may utilize the opposing energy modes to apply a feathering load technique, which causes the end effector60002to maintain a predetermined compression onto the grasped tissue at a constant, or substantially constant, value while applying the one of the offset and opposing energy modes to the grasped tissue. As the grasped tissue thins during welding, a short circuit may be detected60116by the control circuit760. For example, the thinning tissue may expose a pre-existing metallic object (e.g. staple or clip) in the tissue, which may cause the short circuit. In response, the control circuit760may switch to the offset energy mode60118to mitigate the short circuit. In certain instances, the process60150and/or the process60100can be modified to begin with the offset energy mode instead of the opposing energy mode. In such instances, the process60150and/or the process60100may switch from the offset energy mode to the opposing energy mode to mitigate the short circuit. In certain instances, one of the offset and opposing energy modes can be utilized in an initial tissue warming portion of a tissue treatment cycle, while the other one of the offset and opposing energy modes can be utilized in a tissue welding portion of the tissue treatment cycle, which follows the tissue warming portion. In various aspects, The control circuit760can be configured to cause the RF energy source794to adjust power levels in segmented electrodes that are kept in an active state following the detection of a short circuit. The adjustments may include increasing the power levels to compensate for the segmented electrodes deactivated in response to the short circuit. In various aspects, the short circuit between one or more segmented electrodes of the electrode assemblies60036,60026,60027can be detected by incorporating temperature sensors such as, for example, thermocouples at, or near, the segmented electrodes to detect PTC transition temperatures Ts. A short circuit due to a pre-existing metallic object such as a staple60033between a segmented electrode60026cand a segmented electrode60036e, for example, causes a temperature increase in the PTC segment60042eto, or beyond the PTC transition temperature Ts. The increase is detectable by the control circuit760based on signals generated by the temperature sensors. In response, the control circuit760may adjust one or more parameters of the RF energy source794to mitigate the short circuit. In various aspects, a short circuit between segmented electrodes of the electrode assemblies60036,60026,60027, due for example to a pre-existing metallic object in the tissue, abnormally changes an electric output of such segmented electrodes beyond the electric output expected during normal operating conditions. Further, the magnetic field induced by the electric output in the event of a short circuit is different than magnetic field induced during normal operations. In various instances, the short circuit between segmented electrodes of the electrode assemblies60036,60026,60027such as, for example, segmented electrode60026c,60036ecan be detected by incorporating magnetic sensors at, or near, the segmented electrodes60026c,60036eto measure a parameter of the magnetic field induced by the electric output of the segmented electrodes60026c,60036e. If a measured value of the parameter is equal to, or is beyond, a predetermine threshold, the control circuit760detects a short circuit between the segmented electrodes60026c,60036e. Accordingly, the control circuit760can be configured to detect the short circuit based on the signals from magnetic sensors configured to monitor the magnetic field induced by the electric output of segmented electrodes of the electrode assemblies60036,60026,60027. Referring toFIG.182, a graph60190represents a power scheme60191for a tissue treatment cycle and corresponding tissue impedance60192, in accordance with at least one aspect of the present disclosure. The power scheme60191can be implemented by the RF energy source794, for example. In certain instances, the control circuit760is configured to cause the RF energy source794to apply an energy treatment cycle, in accordance with the power scheme60191, to tissue grasped by the end effector60002. In the illustrated example, the power scheme60191includes a first segment160121a(between times t0and ta), a second segment60121b(between times taand tb), and a third segment60121c(between times tband tc). In the first segment60121a, the control circuit760is configured to cause the RF energy source794to apply a therapeutic energy to the tissue in an offset bipolar energy mode. The RF energy source794may activate the electrode assemblies60027,60036to effect the offset bipolar energy mode. The electrode assembly60026remains inactive during the first segment60121a. In at least one example, the electrode assembly60027is configured as a source electrode, while the electrode assembly60036is configured as a return electrode. In other examples, the RF energy source794may reverse the circuit polarity such that the electrode assembly60036becomes the source electrode, and the electrode assembly60027becomes the return electrode. In the second segment60121b, the control circuit760is configured to cause the RF energy source794to apply a therapeutic energy to the tissue in a hybrid mode using a combination of the opposing and offset bipolar energy modes. The RF energy source794may activate the electrode assembly60026to effect the opposing bipolar energy mode during the second segment60121b. In the hybrid mode, the offset bipolar energy mode is gradually decreased while the opposing bipolar energy mode is gradually increased, as time transitions toward tb. In other words, energy flow through the electrode assembly60026is gradually increased, while energy flow through the electrode assembly60027is gradually decreased In the third segment60121a, the control circuit760is configured to cause the RF energy source794to apply a therapeutic energy to the tissue in an opposing bipolar energy mode. The RF energy source794may cause the electrode assemblies60026,60036to effect the opposing bipolar energy mode. The electrode assembly60027is deactivated during the third segment60121c. In at least one example, the electrode assembly60026is configured as a source electrode, while the electrode assembly60036is configured as a return electrode. In other examples, the RF energy source794may reverse the circuit polarity such that the electrode assembly60036becomes the source electrode, and the electrode assembly60026becomes the return electrode. Referring toFIGS.183,184,185, and186, anvils60210,60220are similar in many respects to the anvil60020. For example, anvils60210,60220can be readily utilized with the end effector60002, and similarly include rows of staple pockets60021,60022and electrode assemblies60026,60027, with or without PTC segments60053a-c,60054a-c. In the examples illustrated inFIGS.183-186, the electrode assemblies60026,60027lack PTC segments. In other examples, however, the electrode assemblies60026,60027may include PTC segments60053a-c,60054a-c, as described in connection with the anvil60020. Furthermore, the anvils60210,60220are assembled in different ways, and from different components. For example, the anvils60210,60220include different electrode carriers60211,60221configured to accommodate the electrode assemblies60026,60027. The electrode assemblies60026,60027are manufactured separately, then assembled with the electrode carriers60211,60221. In at least one example, the electrode assemblies60026,60027are assembled with the electrode carriers60211,60221by press-fitting, snap-fitting, or interference-fitting, for example, into corresponding longitudinal slots60213,60214and60223,60224, defined in tissue-contacting surfaces60216,60226of the anvil carriers60211,60221, respectively. In other instances, an adhering agent such as any suitable glue can be utilized to fix the electrode assemblies60026,60027to the anvil carriers60211,60221, respectively. The anvil carrier60211of the anvil60210defines an anvil cap60212integrated therewith. On the other hand, the anvil carrier60221of the anvil60220includes separate carrier portions60221a,60221bthat are manufactured separately, and configured to be assembled with a separate anvil cap60222. The anvil caps60212,60222bridge longitudinal anvil slots60215,60225configured to slidably accommodate an I-beam764. In various aspects, the electrode carriers60211,60221are configured to provide structural support to the anvils60210,60220, reduce I-beam friction in the longitudinal slots60215,60225, and/or insulate the metallic anvil components from the electrode assemblies60026,60027, and ease assembly thereof into the anvils60210,60220, respectively. Further to the above, the anvil carriers60211,60221include sidewalls60231,60232,60233,602234keyed for mating engagement with sidewalls of staple pocket carriers60217,60218,60227,60228, respectively. In certain examples, the anvil carriers60211,60221are configured to slidably enter into a locking engagement with staple pocket carriers60217,60218,60227,60228, respectively. In certain instances, the locking engagements can be in the form of press-fit engagements, snap-fit engagements, interference-fit engagements, or any other suitable engagement. Further, in certain instances, the anvil carriers60211,60221and corresponding staple pocket carriers60217,60218,60227,60228, can be welded using any suitable welding technique. In certain instances, as illustrated inFIGS.183-186, the sidewalls60231,60232,60233,602234of the electrode carriers60211,60221define longitudinally-extending lateral slots configured to slidably receive longitudinally-extending lateral portions of the staple pocket carriers60217,60218,60227,60228, respectively, for assembly therewith. In certain examples, mating portions of the staple pocket carriers60217,60218,60227,60228are insertable into the slots of the sidewalls60231,60232,60233,602234in a distal to proximal direction. In such examples, nose, or distal, portions of the anvils60210,60220are attached to distal portions of the electrode carriers60211,60221, respectively, after assembly of the staple pocket carriers60217,60218,60227,60228with the electrode carriers60211,60221. In other examples, as illustrated inFIG.187, an electrode carrier60211′ of an anvil60210′, which is similar in many respects to the anvil60210, may include an integral nose, or distal, portion60219. In such instances, staple pocket carriers60217,60218can be assembled with the electrode carrier60211′ by laterally inserting mating portions of the staple pocket carriers60217,60218into the slots defined by the side walls60231,60232of the electrode carrier60211′. In various aspects, one or more surfaces of the electrode carriers60211,60221are covered, or coated, with an insulative material to isolate metallic components of the anvils60210,60220from the electrode assemblies60026,60027. The insulative coatings on internal surfaces of the electrode carriers60211,60221, which interact with the I-beam764during staple firing, also act as friction-reducing coatings. In such instances, the anvil longitudinal slots60215,60225can be manufactured cheaply, using looser tolerances, while manufacturing the insulating/friction-reducing coatings to tighter specifications to compensate for the discrepancies/defects in the anvil longitudinal slots60215,60225. FIG.188illustrates an anvil60240similar in many respects to the anvils60210,60220. In the illustrated example, the anvil60240includes separately-manufactured anvil cap60242, staple pocket carriers60247,60248, and electrode carriers60241,60243. The staple pocket carriers60247,60248include longitudinal openings defined in ledges60253,60254configured to receive, and matingly engage with, securing features60251,60252of the electrode carriers60241,60243. In various instances, electrode sticking/charring is associated with energy application to tissue by an end effector such as, for example, the end effector60002. Energy travel through tissue between the electrode assemblies60026,60027of the anvil60020and the electrode assembly60036of the cartridge60030may damage the electrode assemblies by sticking and/or charring. To improve the life cycle of a surgical instrument60000, the end effector60002is configured to concentrate the energy near disposable components of the end effector60002to protect against, or reduce the damage cause by, sticking and/or charring in non-disposable components. In the illustrated example, the cartridge60030is disposable, and the anvil60020is non-disposable. Consequently, the cartridge60030is replaced with a new cartridge60030after every firing, while the same anvil60020is utilized throughout the life cycle of the surgical instrument60000. Accordingly, the end effector60002is configured to protect against, or reduce the damage cause by, sticking and/or charring in the electrode assemblies60026,60027by concentrating the energy near the electrode assembly60036. In the illustrated example, this is achieved by designing the surface area of the segmented electrodes60026a-c,60027a-cto be greater than the surface area of corresponding segmented electrodes60036a-f. In other instances, energy concentration can also be achieved by designing the disposable segmented electrodes60036a-fto include raised portions, which can be spine-like portions, for example. FIG.189is a schematic view of an end effector60502including an anvil60520and a staple cartridge60530. The end effector60502is similar in many respects to the anvil60020, which are not repeated herein for brevity. For example, the end effector60502can be utilized with the surgical instrument60000, and is configured to apply a tissue treatment cycle to tissue grasped between the anvil60520and the cartridge60530. The tissue treatment cycle may include a tissue sealing phase and a tissue stapling phase, for example, which can be administered simultaneously, sequentially, or in a staggered manner. The anvil60520includes a longitudinal slot60525configured to slidably accommodate the I-beam764. Rows of staple pockets60521,60522are disposed on opposite sides of the longitudinal slot60525. The anvil60520further includes electrode assemblies60526,60527also disposed on opposite sides of the longitudinal slot60525. The electrode assemblies60526,60527include rows of segmented electrodes60526a-c,60527a-c. In the illustrated example, two rows of staple pockets and one row of segmented electrodes are depicted on each side of the longitudinal slot60525. Further, each row of segmented electrodes includes three segmented electrodes. These numbers, however, are for illustrative purposes, and should not be construed as limiting. In other examples, the anvil60520may include two, three, five, or six rows of staple pockets, and/or one, three, or four rows of segmented electrodes each includes two, four, five, or six segmented electrodes, for example. Further to the above, the cartridge60530includes a longitudinal slot60535configured to slidably accommodate the I-beam764. Rows of staple cavities60531,60532on opposite sides of the longitudinal slot60535. The cartridge60530further includes electrode assemblies60536,60537also disposed on opposite sides of the longitudinal slot60535. The electrode assemblies60536,60537include rows of segmented electrodes60536a-b,60537a-b. In the illustrated example, two rows of staple cavities and one row of segmented electrodes are depicted on each side of the longitudinal slot60535. Further, each row of segmented electrodes includes two segmented electrodes. These numbers, however, are for illustrative purposes, and should not be construed as limiting. In other examples, the cartridge60530may include two, three, five, or six rows of staple pockets, and/or one, three, or four rows of segmented electrodes each includes three, four, five, or six segmented electrodes, for example. In the illustrated example, the segmented electrodes60526a-c,60527a-c,60536a-b,60537a-bare separately connected to the RF energy source794. This configuration permits the control circuit760to cause the RF energy source794to selectively activate and deactivate the individual electrode segments in accordance with predetermined tissue treatment cycles and/or in response to certain events such as, for example, the detection of a short circuit in connection with one or more of the segmented electrodes, as described in greater detail elsewhere herein. In various aspects, a multiplexer may distribute the RF energy from the RF energy source794to the various segmented electrodes as desired under the control of the control circuit760, for example. In certain instances, one or more of the segmented electrodes60526a-c,60527a-c,60536a-b,60537a-bis separately connected to a separate conductor configured to separately connect to the RF energy source794, which may include individual power sources for one or more of the segmented electrodes60526a-c,60527a-c,60536a-b,60537a-b, for example. The conductors can be responsible for transmitting control, sensing, communication, and/or other signals. The individual conductors may originate at a processor. In certain instances, the processor can reside locally in the end effector60502. In other instances, the processor can be located proximally such as, for example, in a proximal housing of the surgical instrument60000, or at the RF energy source794. In various instances, a multiplexor can be employed, for example, at the end effector60502to control the segmented electrodes60526a-c,60527a-c,60536a-b,60537a-b. In certain instances, where a proximal processor (e.g. at a proximal housing of the surgical instrument60000or at the RF energy source794) is involved, a single conductor may extend from the processor to the end effector60502, which may split into separate connections for each of the segmented electrodes60526a-c,60527a-c,60536a-b,60537a-b, for example. Alternatively, individual conductors, which can be incorporated into a flex circuit for example, may extend from the processor to each of the segmented electrodes60526a-c,60527a-c,60536a-b,60537a-b. In other instances, as illustrated inFIGS.190and191, an end effector60502′, which is similar in many respects to the end effector60502, which are not repeated herein for brevity, may further include one or more passive switches, current limiting elements, energy-sensitive resistance elements, or locally-adjustable resistance elements, which can be in the form of positive temperature coefficient (PTC) segments, for example. In the illustrated example, the end effector60502′ includes anvil electrode assemblies60526′,60527′ and cartridge electrode assemblies60536′,60537′, wherein each of the segmented electrodes60526a-c,60527a-c,60536a-b,60537a-bis connected in series, or alternatively in parallel, to a PTC segment. In the illustrated example, each of the segmented electrodes60526a-c,60527a-c,60536a-b,60537a-bis connected in series to one of the PTC segments60553a-c,60554a-c,60542a-b,60543a-b. Further to the above, since the RF energy source794is independently connected to each of the segmented electrodes60526a-c,60527a-c,60536a-b,60537a-b, the control circuit760can be configured to detect a location of a short circuit by detecting an increase in the resistance of a PTC segment through a measured change current and/or voltage. In response, the control circuit760may issue an alert, for example through the display711, indicating the location of the effected segmented electrodes. Additionally, or alternatively, the control circuit760can be configured to deactivate the affected segmented electrodes at the determined location of the short circuit. Also, since the RF energy source794is independently connected to each of the segmented electrodes60526a-c,60527a-c,60536a-b,60537a-b, the control circuit760can be configured to prompt a clinician for instructions on which of the segmented electrodes to activate for a tissue treatment cycle.FIG.192is a logic flow diagram of a process60570depicting a control program or a logic configuration for applying a tissue treatment cycle to a tissue grasped by an end effector such as the end effector60502exclusively using segmented electrodes selected by a clinician. In certain instances, the process60570can be implemented by the surgical instrument60000, for example. The process60570can be executed by a control circuit760. In certain instances, the memory circuit68008stores machine-executable instructions that, when executed by the processor68002, cause the processor68002to execute machine instructions to implement the process60570, for example. In the illustrated example, the process60570includes prompting60571a clinician to select segmented electrode. In at least one example, the control circuit760causes the display711to present the schematic diagram ofFIG.189. The clinician may then select segmented electrodes to be activated, for example by pressing onto the display711. The process60570further includes prompting60572the clinician to select a tissue treatment cycle, only activating60573the selected segmented electrodes, and initiating60574the tissue treatment cycle only using the selected electrodes. In certain instances, the control circuit760is configured to automatically initiate the tissue treatment cycle, once clinician selections are made. In certain examples, the automatic tissue treatment cycle initiation can be further based on a tissue parameter. In such examples, initiation of the tissue treatment cycle is triggered by (i) receipt of the clinician selection(s), and (ii) detecting that a measurement of a tissue parameter is within a predefined range, or is equal to, or beyond, a predetermined threshold. In certain instances, the tissue parameter is an impedance of the tissue grasped by the end effector60502, for example. As described elsewhere herein in greater detail, tissue impedance of a tissue portion can be detected, for example by a control circuit760, by causing a sub-therapeutic signal to be passed through the tissue portion, receiving measurements from a voltage sensing circuit924and the current sensing circuit914, and dividing the measurements from the voltage sensing circuit924, by the corresponding measurements from the current sensing circuit914, for example. The control circuit760is then configured to only activate the selected segmented electrodes. Accordingly, only the selected segmented electrodes are utilized in treating the tissue. This approach causes energy to flow in specific, preselected, portions of the jaws, while maintaining the remainder of the jaws in a cooler state. In various aspects, the power requirements for effectively sealing a tissue grasped by the end effector60502may vary depending, for example, on the thickness and/or type of the grasped tissue. In certain instances, impedance of the grasped tissue can be indicative of the power required to effectively seal the tissue. Attempting to seal a grasped to tissue while available power is less than the required power can yield an ineffective, incomplete, tissue seal. This can yield undesirable consequences particularly if the grasped tissue includes a blood vessel. FIG.193is a logic flow diagram of a process60580depicting a control program or a logic configuration for addressing situations where power available to apply in a tissue treatment cycle is less than the power requirements for an effective tissue seal. In certain instances, the process60580can be implemented by the surgical instrument60000, for example. The process60580can be executed by a control circuit760. In certain instances, the memory circuit68008stores machine-executable instructions that, when executed by the processor68002, cause the processor68002to execute machine instructions to implement the process60580, for example. In the illustrated example, the process60580includes detecting60581a tissue parameter of a tissue grasped by an end effector such as, for example, the end effector60502, and determining based on the measured tissue parameter if60582available power is sufficient to yield an effective tissue seal via a tissue treatment cycle. In certain instances, the control circuit760is configured to detect60581based on signals from one or more sensors, e.g. current sensors, indicative of the tissue parameter. The tissue parameter can be a tissue impedance or a tissue thickness, for example. In such instances, the control circuit760can further be configured to ascertain the power required to achieve an effective tissue seal via a tissue treatment cycle based on the detected tissue parameter from information stored in a storage medium such as, for example, the memory circuit68008. The information can be in the form of a database, equation, formula, and/or table relating various values of the tissue parameter to corresponding values of the power requirement. Furthermore, the control circuit760can be configured to compare the ascertained power requirement to available power to determine whether the available power is sufficient to yield an effective tissue seal. In other instances, the information stored in the memory circuit68008can be in the form of a range, or a listing, of values of the tissue parameter suitable for achieving an effective tissue seal via the tissue treatment cycle. In any event, If60581it is determined that the available power is sufficient to yield an effective tissue seal, the process60580authorizes60583the tissue treatment cycle with no change. For example, the process60580may apply the tissue treatment cycle simultaneously to all portions of the end effector60502. If60582, however, the process60580determines that the available power is insufficient to yield an effective tissue seal via the tissue treatment cycle, the process60581may separately apply60584the tissue treatment cycle in discrete portions of the end effector60502. The control circuit760may be configured to implement the separate application60584of the tissue treatment cycle to discrete portions of the end effector60502by separately activating groups of the segmented electrodes of the electrode assemblies60526,60527,60536,60537along the length of the end effector to separately effect a tissue seal in discrete portions of the end effector60502. Accordingly, all of the available power will be fully directed to achieving an effective tissue seal at a first tissue portion in a first discrete portion of the end effector60502, then at a second tissue portion in a second discrete portion the end effector60502, and so forth, until all tissue portions in all discrete portions of the end effector60502are treated in accordance with the tissue treatment cycle. As discussed supra, the RF energy source794is independently connected to each of the segmented electrodes60526a-c,60527a-c,60536a-b,60537a-b. Accordingly, the control circuit760may cause RF energy source794to exclusively activate the segmented electrodes60526a,60536ato apply a tissue treatment cycle to a first tissue portion between the segmented electrodes60526a,60536ayielding an effective tissue seal of the first tissue portion with an available power lesser than the power required to achieve an effective tissue seal for all of the tissue grasped by the end effector60502simultaneously. Then, the control circuit760may cause RF energy source794to exclusively activate the segmented electrodes60526b,60536bto apply the tissue treatment cycle to a second tissue portion between the segmented electrodes60526b,60536b, and so forth until the tissue treatment cycle is applied to all the tissue grasped by the end effector60502. In various aspects, different portions of a tissue grasped by the end effector60502may require different amounts of time for achieving an effective tissue seal via a tissue treatment cycle. In certain instances, the amount of time required for achieving an effective tissue seal can be a function of a tissue parameter of the tissue portion such as, for example, an impedance of the tissue portion. As described elsewhere herein in greater detail, tissue impedance of a tissue portion can be detected, for example by a control circuit760, by causing a sub-therapeutic signal to be passed through the tissue portion, receiving measurements from a voltage sensing circuit924and the current sensing circuit914, and dividing the measurements from the voltage sensing circuit924, by the corresponding measurements from the current sensing circuit914, for example. FIG.194is a logic flow diagram of a process60590depicting a control program or a logic configuration for balancing different sealing times for different tissue portions exposed to a tissue treatment cycle by an end effector. In certain instances, the process60590can be implemented by the surgical instrument60000, for example. The process60590can be executed by a control circuit760. In certain instances, the memory circuit68008stores machine-executable instructions that, when executed by the processor68002, cause the processor68002to execute machine instructions to implement the process60590, for example. The process60590includes determining60591a first sealing time associated with applying a tissue treatment cycle to a first portion of a tissue grasped by the end effector60502, determining60592a second sealing time associated with applying a tissue treatment cycle to a second portion of the tissue grasped by the end effector60502, staggering/coordinating60593activation of a first segmented electrode positioned against the first portion of tissue and a second segmented electrode positioned against the second portion of tissue such that the first sealing time and the second sealing time are completed concurrently. In other words, begin the longer sealing time prior to the shorter sealing to ensure a concurrent completion of both sealing times. Further to the above, determining60591the first sealing time and determining60592the second sealing times can be achieved by measuring a first tissue impedance of the first portion of the tissue and measuring a second tissue impedance of the second portion of the tissue. The control circuit760may cause segmented electrodes of the end effector60502, which are positioned against the first and second tissue portions, to pass sub-therapeutic signals through the first and second tissue portions for the purposes of determining their tissue impedances. Further, the control circuit760can further be configured to ascertain a sealing time of a tissue portion based on its tissue impedance from information stored in a storage medium such as, for example, the memory circuit68008. The information may include a correlation between tissue impedance values and corresponding sealing time values, which can be in the form a database, equation, formula, and/or table relating various values of the tissue impedance to corresponding values of the sealing time. In other instances, a process similar in many respects to the process60590, which are not repeated herein for brevity, may stagger/coordinate activation of the first segmented electrode positioned against the first portion of tissue and the second segmented electrode positioned against the second portion of tissue for other purposes. For example, the process may stagger/coordinate the activations to avoid an occurrence of a particular event in the tissue treatment cycle simultaneously at the first tissue portion and the second tissue portion. In certain instances, the particular event can be a point during the first and second sealing times where a maximum power is applied to the first and second tissue portions, for example. Accordingly, the control circuit760can be configured to cause the RF energy source794to activate the first segmented electrode prior to activation of the second segmented electrode. In certain instances, where the first sealing time is greater than the second sealing time, the control circuit760can be configured to cause the RF energy source794to activate the second segmented electrode after completion of the maximum power event by the first segmented electrode, for example. In certain examples, the maximum power event is defined by a power level greater than or equal to a predetermined threshold. In certain examples, the maximum power event is defined by a minimum tissue impedance threshold. Further to the above, in various aspects, the control circuit760can be configured to rapidly alternate activation of segmented electrodes to concurrently seal different portions of a tissue grasped by the end effector60502. For example, the control circuit760may cause the RF energy source794to rapidly alternate activation of groups of segmented electrodes positioned against different tissue portions, wherein only one of the groups is active at any point of time, until a complete application of a tissue treatment cycle is achieved in all the tissue portions. Further to the above, in various aspects, the control circuit760can be configured to sequentially activate segmented electrodes to seal different portions of a tissue grasped by the end effector60502. For example, the control circuit760may cause the RF energy source794to activate a proximal subset of segmented electrodes to apply a tissue treatment cycle to a proximal portion of the tissue grasped by the end effector60502, prior to activation of a distal subset of segmented electrodes to apply a tissue treatment cycle to a distal portion of the tissue grasped by the end effector60502. FIG.195is a logic flow diagram of a process60200depicting a control program or a logic configuration for detecting and addressing a short circuit during a tissue treatment cycle applied to tissue grasped by the end effector60502. The process60200includes passing60201a first sub-therapeutic signal through a first tissue portion of the tissue grasped by the end effector60502, and monitoring60202a first tissue impedance of the first tissue portion based on the first sub-therapeutic signal. The process60200further includes passing60203a second sub-therapeutic signal through a second tissue portion of the tissue grasped by the end effector60502, wherein the second tissue portion is different than the first tissue portion. The process60200further includes monitoring60204a second tissue impedance of the second tissue portion based on the second sub-therapeutic signal. In addition, the process60200includes adjusting60205a first therapeutic signal configured to be passed through the first tissue portion based on the first tissue impedance, and adjusting60206a second therapeutic signal configured to be passed through the second tissue portion based on the first tissue impedance and the second tissue impedance. Furthermore, the process60200includes issuing60207an alert indicative of a short circuit based on the first tissue impedance. In certain instances, the first tissue portion is proximal to the second tissue portion. For example, the first tissue portion may be positioned between the segmented electrodes60526a,605236a, while second tissue portion can be positioned between the segmented electrodes60526b,60536b. FIG.196is a graph60260representing an interrogation of the first tissue portion, in accordance with the process60200. The graph60260includes multiple graphs depicting time (t) on the X-axis vs source electrode (e.g.60526a) active status60261, return electrode (e.g. segmented electrode60536a) active status60262, power level60263, and tissue impedance60264, on the Y-axis. In the illustrated example, the control circuit760is configured to cause the RF energy source794to selectively activate60265,60266segmented electrodes60526a,60536aabutting the first tissue portion to pass60201the first sub-therapeutic signal between activated segmented electrodes60526a,60536a, for example. The control circuit760is further configured to cause the RF energy source794to monitor60202the first tissue impedance curve60267of the first tissue portion. In the illustrated example, the monitored first tissue impedance curve60267is indicative of a short circuit between segmented electrodes60526a,60536adue to the presence of a metallic object such as, for example, a previously fired staple in the first tissue portion. The first tissue impedance curve60267shows an abnormal, or premature, decrease prior to stopping the first sub-therapeutic signal, which is indicative of the short circuit. In certain instances, a storage medium such as, for example, the memory circuit68008stores information representing an expected tissue impedance in response to a sub-therapeutic signal. The information can be in the form of one or more curves, tables, databases, equations, or any suitable medium. A deviation from the expected tissue impedance, as shown in the curve60267indicates a short circuit. Further to the above, the control circuit760may be configured to similarly interrogate the second tissue portion abutting segmented electrodes60526b,60536b. In addition, the control circuit760may cause the RF energy source794to adjust a first therapeutic signal configured to be passed between the segmented electrodes60526a,60536a, and a second therapeutic signal configured to be passed between the segmented electrodes60526b,60536b, to address the detected short circuit. In certain instances, adjusting the first therapeutic signal includes a reduction in a power parameter of the first therapeutic signal. In certain instances, adjusting the first therapeutic signal includes reducing the first therapeutic signal to a sub-therapeutic level. In other instances, adjusting the first therapeutic signal includes reducing the first therapeutic signal to a tissue warm-up only level. In other instances, adjusting the first therapeutic signal comprises deactivating at least one of the segmented electrodes60526a,60536a. In certain instances, adjusting the second therapeutic signal includes any modification suitable for extending a thermal effect of the second therapeutic signal to the first tissue portion to compensate for the decrease in the power parameter of the first therapeutic signal. In certain instances, adjusting the second therapeutic signal includes an increase in a power parameter of the second therapeutic signal. In other instances, adjusting the second therapeutic signal includes an increase in the time the second therapeutic signal is applied to the tissue, which can be at the same voltage, or at a lower voltage. In other instances, the second therapeutic signal is adjusted to cause an over-sealing of the second tissue portion, in response to the short circuit associated with the adjacent first tissue portion. In various instances, the adjustments to the first and second therapeutic signals are performed in accordance with predetermined tissue treatment cycles stored in a storage medium such as, for example, the memory circuit68008. The control circuit760may, in response to detecting the short circuit between the segmented electrodes60526a,60526a, select a tissue treatment cycle with first and second therapeutic signals adjusted, as described supra, for addressing the short circuit situation. In various instances, the control circuit760may respond to the detection of the short circuit by causing the RF energy source794to actively cycle both source and return segmented electrodes to seal around the tissue portion with a detected short circuit. Furthermore, various neighboring segmented electrodes can also be utilized in offset and/or opposing energy delivery modes to seal around the tissue portion with a detected short circuit including activation/cycling surrounding electrode segments in crisscross configurations, for example. In certain instances, depending on a location of short circuit, the control circuit760may cause the RF energy source794to selectively activate specific segmented electrodes as source electrodes, and simultaneously activating others as return electrodes. Such activations can be cycled or alternated to achieve an effective seal of the entire tissue grasped by the end effector60502, while avoiding the location of the detected short circuit. Electrical arcing is a phenomenon that may occur during application of a sealing energy to a tissue grasped by an end effector60502, for example. In certain instances, the presence of a metallic object such as previously-fired staples adjacent active segmented electrodes may yield electrical arcing. The efficacy of a tissue treatment cycle can be negatively influenced by electrical arcing due to a diversion/leap of the sealing energy away from the intended tissue target. The energy diversion may also cause unintended injury to neighboring tissue. In various instances, the ability of the control circuit760to separately control activation, deactivation, and polarity of each of the segmented electrodes60526a-c,60527a-c,60536a-b,60537a-bfurther allows the control circuit760to manage an arcing event (predicted and/or active) in a localized manner by selectively adjusting various parameters of segmented electrodes near the arcing event, for example. In certain instances, the adjusted parameters are power parameters. In certain instances, the control circuit760may selectively cause the RF energy source794to reduce the voltage across selected pairs of the segmented electrodes60526a-c,60527a-c,60536a-b,60537a-bto address an arcing event. In situations where an active arc has occurred, for example due to the presence of an adjacent metallic object such as previously-fired staples, the control circuit760can be configured to respond by exclusively deactivating the segmented electrodes responsible for the arcing event. Then, the deactivated segmented electrodes can be reactivated to complete a tissue treatment cycle after adjustments are made to the gap between the affected segmented electrodes and/or the voltage level. In certain instances, voltage levels can be reduced, while increasing the tissue treatment time, to still achieve an effective tissue seal with the reduced voltage. In various aspects, the control circuit760is configured to employ a sub-therapeutic signal to test if the power and/or gap adjustments are effective at avoiding recurrence of arcing, prior to restarting the tissue treatment cycle. In various instances, a control circuit760is configured to address an arcing event by increasing an overall tissue gap between jaws of the end effector60502, for example. However, to ensure an effective sealing the tissue with an increased tissue gap, the control circuit760may further increase at least one of a power parameter, for example voltage, or a sealing time of the tissue. The increased power parameter and/or the increased sealing time can be limited to selected pairs of the segmented electrodes60526a-c,60527a-c,60536a-b,60537a-b, for example. In various instances, the control circuit760can be configured to detect an arcing event by analyzing imaging data of the end effector60502during a tissue treatment cycle. Additionally, or alternatively, the arcing event can be detected through a clinician input via the display711, for example. Additionally, or alternatively, the arcing event can be detected by monitoring one or more parameter of the RF energy source794, for example. Additionally, or alternatively, the arcing event can be detected by monitoring tissue temperature during the tissue treatment cycle via temperature sensors in the end effector60502, for example. A deviation from an expected correlation between the energy supplied to the tissue portion and the temperature of the tissue portion can indicate an arcing event associated with segmented electrodes configured to supply energy to the tissue portion. In various instances, the ability of the control circuit760to separately control activation, deactivation, and polarity of each of the segmented electrodes60526a-c,60527a-c,60536a-b,60537a-bfurther allows the control circuit760to manage capacitive coupling issues which may occur within the shaft of the surgical instrument60000. In certain instances, the capacitive coupling may result in reducing power supply to the end effector60502, for example. The reduction may render available power ineffective in simultaneously applying a tissue treatment cycle to an entire tissue grasped by the end effector60502. In response, the control circuit760can be configured to separately apply the tissue treatment cycle to portions of the grasped tissue. This can be achieved, for example, by selectively activating subsets of the segmented electrodes of the end effector60502, one subset at a time, to separately apply the tissue treatment cycle to the tissue portions. For example, a first subset (e.g. proximal subset) of the segmented electrodes of the end effector60502can be activated to apply the tissue treatment cycle to a first portion (e.g. proximal portion) of the grasped tissue. The first subset is then deactivated, and a second subset (e.g. distal subset positioned distally with respect to the proximal subset) can be activated to apply the tissue treatment cycle to a second portion (e.g. distal portion positioned distally with respect to the proximal portion) of the tissue. In other instances, the control circuit760can be configured to address a reduction in power supply by alternating activation of the subsets of the segmented electrodes. In such instances, only one subset of the segmented electrodes is activated at each point of time. In other instances, the control circuit760can be configured to address a reduction in power supply by selecting a different tissue treatment cycle, for example one with a reduced power requirement and an increased sealing time. In various instances, the ability of the control circuit760to separately control activation, deactivation, and polarity of each of the segmented electrodes60526a-c,60527a-c,60536a-b,60537a-bfurther allows the control circuit760to dynamically adjust energy modalities in a tissue treatment cycle applied to a tissue grasped by the end effector60502. The different energy modalities can be applied to different tissue portions, or can be applied to the same tissue portion, or the entire grasped tissue, in a predetermined sequence. In certain instances, the control circuit760is configured to selectively activate one or more segmented electrodes to apply a monopolar energy modality, a bipolar energy modality, and/or a combination, or blended, bipolar/monopolar energy modality to a tissue portion abutting the activated segmented electrodes. Further to the above, a number of factors can be considered in the energy modality selection by the control circuit760including, but not limited to, closure load response, the percentage of jaw closure, tissue impedance, tissue location and/or type, and/or the presence of a short circuit. In certain instances, detecting a blood vessel may cause the control circuit760to select the bipolar modality. In certain instances, detecting a tissue thickness beyond a predetermined threshold, for example, may cause the control circuit760to select a tissue treatment cycle with an initial bipolar energy modality, to reduce the thickness of the tissue, an intermediate monopolar energy modality to increase the sealing speed, and then a final bipolar energy modality to complete the tissue seal. Further to the above, if a short circuit is detected, due for example to the presence of a previously-fired staple, the control circuit760can be configured to select a tissue treatment cycle with a bipolar energy modality, and a monopolar energy modality, especially modified to address the short circuit. Further, the control circuit760can be configured to selectively apply the bipolar energy modality only to a subset of the segmented electrodes that are not affected by the detected short circuit, and then apply the monopolar energy modality to all the segmented electrodes. For example, the control circuit760may cause the RF energy source794to deactivate the segmented electrodes where the short circuit is detected, and then apply the bipolar energy modality to the remaining segmented electrodes. Next, the control circuit760may cause the RF energy source794to reactivate the previously-deactivated segmented electrodes for application of the monopolar energy modality to the tissue. FIGS.197-203illustrate a number of energy profiles, or therapeutic signals,60300,60310,60320,60330,60340,60350,60360depicted in graphs representing Tissue impedance, Voltage, Power, and Current curves associated with application of the therapeutic signals60300,60310,60320,60330,60340,60350,60360to tissue grasped by the end effector60502, for example. It is understood that the therapeutic signals60300,60310,60320,60330,60340,60350,60360are for illustrative purposes only and, as such, are not limiting. Other high, medium, and low energy profiles can be utilized in tissue treatment cycles effected by the control circuit760. In certain instances, two or more of the therapeutic signals60300,60310,60320,60330,60340,60350,60360can be delivered to different tissue portions in different zones along a length of the end effector60502in a tissue treatment cycle effected by the control circuit760. The different zones can be defined by different subsets of the segmented electrodes60526a-c,60527a-c,60536a-b,60537a-b. In certain instances, the two or more of the therapeutic signals60300,60310,60320,60330,60340,60350,60360can be delivered simultaneously in the different zones in a tissue treatment cycle. In certain instances, the different zones include a proximal zone and a distal zone. In other instances, the different zones include a proximal zone, one or more intermediate zones, and a distal zone. In various instances, various parameters of the therapeutic signals60300,60310,60320,60330,60340,60350,60360can be stored in a storage medium such as, for example, the memory circuit68008, which can be accessed to implement a tissue treatment cycle, for example. The control circuit760can be configured to select one or more of the therapeutic signals60300,60310,60320,60330,60340,60350,60360for execution in a tissue treatment cycle applied to one or more zones of the end effector60502based on one or more conditions of the grasped tissue in the one or more zone including tissue thickness, tissue type, tissue location, and/or tissue impedance, for example. Referring primarily toFIGS.1and155, a surgical instrument (e.g. surgical instruments1000,60000) can include an end effector (e.g. end effectors1300,60002,60502). One or motor assemblies can be motivated by a control circuit (e.g. control circuit760) to effect one or more functions/motions of the end effector including closure of the jaws, firing of the staples, and/or rotation and/or articulation of the end effector about a central longitudinal axis (e.g. axis60005) of the surgical instrument. Various mechanisms for articulation, rotation, closure, and firing of an end effector are described in greater details elsewhere in the present disclosure, and are not repeated herein for brevity. In various aspects, the control circuit760can be configured to cause one or more motor assemblies to effect various rotation and/or articulation motions of an end effector (e.g. end effectors1300,60002,60502) in response to inputs from a clinician to align the jaws of the end effector with respect to a tissue. The clinician may then position one of the jaws behind the tissue. Further, the control circuit760can also be configured to cause one or more motor assemblies to motivate the jaws to grasp the tissue in a closure motion, in response to another clinician input. In certain instances, closure of the jaws can be reversed multiple times until a satisfactory tissue bite is achieved. At such point, the control circuit760can be configured to cause a firing driver such as, for example, the I-beam764to be advanced distally to fire staples stored in staple cavities of a staple cartridge into the grasped tissue. In certain instances, the clinician may elect to perform additional rotational adjustments of the end effector in the vicinity of the tissue such as, for example, prior to end effector closure, during end effector closure, and following end effector closure. In certain instances, the clinician may elect to perform additional rotational adjustments of the end effector after a successful end effector closure, or tissue bite, has been achieved by prior to applying a therapeutic energy to the tissue, or prior to firing staples into the tissue. The additional rotational adjustments can be fine rotational adjustments with different rotational parameters than standard rotational adjustments to protect the tissue and/or aid less-experienced clinicians. FIG.204is a logic flow diagram of a process60400depicting a control program or a logic configuration for adjusting a parameter of rotation of an end effector of a surgical instrument based on whether a tissue is being grasped by the end effector as determined based on at least one impedance measurement, in accordance with at least one aspect of the present disclosure. In various instances, the process60400can be implemented by any suitable surgical instrument such as, for example, surgical instruments1000,60000including any suitable end effector such as, for example, end effectors1300,60002,60502. However, for brevity, the following description of the process60400will focus on its implementation in the surgical instrument60000and the end effector60502, for example. In certain instances, the memory68008stores program instructions that, when executed by the processor68002, cause the processor68002to perform one or more aspects of the process60400. The process60400includes causing60401a sub-therapeutic signal to be provided to the end effector60502. For example, the control circuit760may cause the RF energy source794to attempt to pass a sub-therapeutic signal between the electrode assemblies60526,60536. The process60400further includes determining60402an impedance between the electrode assemblies60526,60536in response to the sub-therapeutic signal to assess whether tissue is being grasped by the end effector60502. The process60400further includes selecting60403a parameter of rotation of the end effector based on at least one impedance measurement. The parameter of rotation of the end effector includes rotation speed, rotation distance, rotation direction, and/or rotation time, for example. As described elsewhere herein in greater detail, the control circuit760is configured to determine60402the impedance between the electrode assemblies60526,60536, in response to the sub-therapeutic signal, based on measurements from a voltage sensing circuit924and the current sensing circuit914, for example. The control circuit760can be configured to divide the measurements from the voltage sensing circuit924, by the corresponding measurements from the current sensing circuit914, for example, to determine the impedance. Further to the above, the control circuit760can be configured to select60403a parameter of rotation of the end effector60502based on a comparison of the impedance measurement to a predetermined threshold. The impedance measurements can be indicative of the presence or absence of tissue in contact with the end effector60502. The control circuit760can be configured to detect an absence of tissue if the impedance measurement is greater than, or equal, to a predetermined threshold, for example due to an open circuit. On the contrary, the control circuit760can be configured to detect a presence of tissue if the impedance measurement is below the predetermined threshold. In certain instances, the predetermined threshold can be stored in a storage medium such as, for example, the memory circuit68008, and can be utilized by the processor68002to determine whether tissue is in contact with the end effector60502. Further to the above, selecting60403a parameter of rotation of the end effector60502can include selecting a speed of rotation, or a distance of rotation of the end effector60502. In certain instances, selecting60403a parameter of rotation of the end effector60502comprises selecting between a first rotational profile and a second rotational profile. The first and second rotational profiles can be stored in a storage medium such as, for example, the memory circuit68008. The control circuit760can be configured to select the first rotational profile in the absence of tissue, and the first rotational profile in the absence of tissue, as determined based on the comparison of the impedance measurements and the predetermined threshold. Further to the above, the first rotational profile may include a first speed of rotation greater than a second speed of rotation of the second rotational profile. In certain examples, the first speed of rotation may be a maximum speed of rotation. In certain example, the second speed of rotation can be a percentage of the first speed of rotation. The percentage can, for example, be selected from a range of about 1% to about 50%. In certain instances, the first rotational profile comprises a greater initial acceleration to a predetermined speed of rotation than the second rotational profile. In certain instances, the first rotational profile may include a first distance of rotation greater than a second distance of rotation of the second rotational profile. In certain examples, the first distance of rotation may be a maximum distance of rotation. In certain example, the second distance of rotation can be a percentage of the first distance of rotation. The percentage can, for example, be selected from a range of about 1% to about 50%. In certain instances, selecting60403a parameter of rotation of the end effector60502includes selecting a parameter of the power supplied to a motor to effect the rotation of the end effector60502. As described elsewhere herein in greater detail, a motor assembly may include a motor and a motor control circuit configured to supply power to the motor in accordance with power parameters selected by the control circuit760, for example. The motor can be configured to cause a rotation of the shaft60004and the end effector60502relative to the housing assembly60006, for example. In certain instances, current supplied to the motor by the motor control circuit can be selected based on the impedance measurement. The control circuit760can be configured to select a first current in the absence of tissue and a second current in the presence of tissue, wherein the first current is greater than the second current. In certain instances, the second current comprises a value of zero. Accordingly, the control circuit760can be configured to deactivate the motor to seize all rotational motions if tissue is detected between the jaws of the end effector60502. Further to the above, if tissue is no longer detected, based on impedance measurements, the control circuit760can be configured to readjust the power parameter of the motor. For example, the control circuit760can be configured to reselect the first current, or reselect the first rotational profile. In other embodiments, as illustrated inFIG.204, the parameter of rotation of the end effector60502can be selected60405based on a closure state of the end effector60502in addition to impedance measurements. Alternatively, the parameter of rotation of the end effector60502can be selected solely based on a closure state of the end effector60502. In certain examples, the parameter of rotation of the end effector60502is adjusted to different values associated with different closure states. For example, the control circuit760can be configured to select a first value for the parameter of rotation of the end effector60502for a fully-open state, select a second value for the parameter of rotation of the end effector60502for a partially-open state, and/or select a select a third value for the parameter of rotation of the end effector60502for a fully-closed state. In certain instances, the first value is greater than the second value, and the second value is greater than third value. The closure state of the end effector60502can be detected60404by the control circuit760based on sensor signals of one or more sensors. For example, sensor signals from the position sensor784(FIG.163) can be indicative of the position of a drive member (e.g. I-beam764or closure drive3800) movable by the motor754to effect a closure of the end effector60502. The position of the drive member can be correlated to the different closure states of the end effector60502. Other sensors788(FIG.163) can also be utilized by the control circuit760to determine the closure states of the end effector60502such as, for example, sensors configured to detect the gap between the jaws of the end effector60502. In other embodiments, the parameter of rotation of the end effector60502can be selected based on a closure load of the end effector60502instead of tissue impedance, or in addition to tissue impedance. In certain examples, the parameter of rotation of the end effector60502is adjusted to different closure loads. For example, the control circuit760can be configured to select a first value for the parameter of rotation of the end effector60502for a first closure load, select a second value for the parameter of rotation of the end effector60502for a second closure load, and/or select a select a third value for the parameter of rotation of the end effector60502for a third closure load. In certain instances, the third closure load is greater than the second closure load which is greater than the first closure load. In such instances, the third value is less than the second value, and the second value is less than first value. In various instances, the control circuit760is configured to detect a closure load of the end effector60502based on current draw by the motor effecting the closure load. A current sensor786can be configured to measure the current draw of the motor. In other embodiments, as illustrated inFIG.204, the parameter of rotation of the end effector60502can be selected60408based on a firing state of the end effector60502in addition to impedance measurements. Alternatively, the parameter of rotation of the end effector60502can be selected solely based on a firing state of the end effector60502. In certain examples, the parameter of rotation of the end effector60502is adjusted to different values associated with different firing states. For example, the control circuit760can be configured to select a first value for the parameter of rotation of the end effector60502for an unfired state, select a second value for the parameter of rotation of the end effector60502for a partially-fired state, and/or select a select a third value for the parameter of rotation of the end effector60502for a fully-fired state. In certain instances, the first value is greater than the second value. In certain instances, the third value is greater than the second value. The firing state of the end effector60502can be detected60404by the control circuit760based on sensor signals of one or more sensors. For example, sensor signals from the position sensor784(FIG.163) can be indicative of the position of a drive member (e.g. I-beam764) movable by the motor754to effect a firing of the staples from the end effector60502. The position of the drive member can be correlated to the different firing states of the end effector60502. In various instances, tissue impedance measurements of a tissue grasped by the end effector60502, as described supra in connection with the process60400ofFIG.204, can be useful in assessing tissue tension cause by over-rotation, or unintended rotation, of the end effector60502. A rotation of the end effector60502about the longitudinal axis60005increases tension on a first tissue portion on a first side of the longitudinal slot60535, while reducing tension on a second tissue portion on a second side, opposite the first side, of the longitudinal slot60535. Consequently, a first tissue thickness of the first tissue portion may be reduced, while a second tissue thickness of the second tissue portion may be increased. Furthermore, the changes in tissue thickness may be accompanied by changes in tissue impedances of the first and second tissue portions due to a change in the fluid content of the tissue portions. FIG.205is a logic flow diagram of a process60600depicting a control program or a logic configuration for adjusting a parameter of rotation of an end effector of a surgical instrument based a detected over-rotation of the end effector, in accordance with at least one aspect of the present disclosure. In various instances, the process60600can be implemented by any suitable surgical instrument such as, for example, surgical instruments1000,60000including any suitable end effector such as, for example, end effectors1300,60002,60502. However, for brevity, the following description of the process60600will focus on its implementation in the surgical instrument60000and the end effector60502, for example. In certain instances, the memory68008stores program instructions that, when executed by the processor68002, cause the processor68002to perform one or more aspects of the process60600. The process60600includes measuring60601a first tissue parameter of a first tissue portion on a first side of a longitudinal slot of an end effector, measuring60602a second tissue parameter of a second tissue portion on a second side of the longitudinal slot of the end effector, adjusting60603a parameter of rotation of the end effector based on a relation between the first tissue parameter and the second tissue parameter. The first and second tissue parameters can, for example, be tissue impedance, or tissue thickness. The control circuit760can be configured to monitor tissue impedance of the first tissue portion and the second tissue portion grasped by the end effector60502. For example, the control circuit760may cause the RF energy source794to pass sub-therapeutic signals between the electrode assemblies60526,60536and between the electrode assemblies60527,60537. The control circuit760may then calculate a first tissue impedance of the first tissue portion and a second tissue impedance of the second tissue portion, based on the sub-therapeutic signals. Furthermore, the control circuit760can be configured to adjust a parameter of rotation of the end effector60502based on the difference between the first and second tissue impedances. In certain examples, the control circuit760can be configured to slow, deactivate, or reverse, end effector rotation if the difference between the first and second tissue impedances is greater than or equal to a predetermined threshold. Further to the above, various adjustments can be made to one or more parameters of rotation of the end effector60502include a rotational position, rotational distance, a rotational speed, a rotational time, and/or a rotational direction to avoid, or mitigate, a detected obstacle. In various aspects, a control circuit760can be configured to adjust a parameter of rotation of the end effector60502in response to detecting a rotation obstacle. The control circuit760can be configured to detect a rotation obstacle if a current draw of the motor effecting a rotation of the end effector60502is greater than, or equal to a predetermined threshold, for example. In various aspects, the control circuit760can be configured to perform a predictive analysis to assess whether a previously-detected obstacle will be reached based on a requested movement by the clinician. Furthermore, the control circuit760may be configured to issue an alert, for example through the display711, and/or seize further rotation of the end effector60502, if it is determined that the requested movement will cause the end effector to reach the obstacle. In certain instances, the a previously-detected obstacle can be in the form of a system constraint such as, for example, a maximum rotation angle, which can be a predetermined maximum rotation angle that will be reached, or exceeded, if the requested movement is complied with. Referring primarily toFIG.189, the end effector60502is can be configured to apply a hybrid tissue treatment cycle to a tissue grasped between the cartridge60530and the anvil60520. The hybrid tissue treatment cycle includes an RF energy phase and a stapling phase, which can be applied separately, or sequentially, to tissue portions along a length of the end effector60502. In the hybrid tissue treatment cycle, RF energy can be applied to the grasped tissue by the electrode assemblies60526,60527,60536,60537. An RF energy zone may be cooperatively defined by segmented electrodes of the electrode assemblies60526,60527,60536,60537, for example. Further, the hybrid tissue treatment cycle also includes deploying staples into the grasped tissue from rows of staple cavities60531,60532, which are deformed by rows of staple pockets60521,60522. A stapling zone may be cooperatively defined by staple cavities60531,60532and corresponding staple pockets60521,60522. In the instance of the end effector60502, the RF zone is laterally surrounded by portions of the stapling zone due to the arrangement of the electrode assemblies60526,60527,60536,60537, the rows of staple cavities60531,60532and rows of staple pockets60521,60522. FIG.206is a logic flow diagram of a process60700depicting a control program or a logic configuration for cooperatively applying the RF energy phase and the stapling phase to tissue portions of a tissue grasped by an end effector60502, for example, in a hybrid tissue treatment cycle. In certain instances, the RF energy phase may be utilized to mitigate, counterbalance, compensate for, and/or offset defects in the stapling phase. In other instances, the stapling phase may be utilized mitigate, counterbalance, compensate for, and/or offset defects in the RF energy phase. In various instances, the process60700can be implemented by any suitable surgical instrument such as, for example, surgical instruments1000,60000including any suitable end effector such as, for example, end effectors1300,60002,60502. However, for brevity, the following description of the process60700will focus on its implementation in the surgical instrument60000and the end effector60502, for example. In certain instances, the memory68008stores program instructions that, when executed by the processor68002, cause the processor68002to perform one or more aspects of the process60700. In the illustrated example, the process60700includes detecting60701a tissue parameter. The tissue parameter can, for example, be a tissue thickness of the tissue grasped by the end effector60502. The process60700further includes detecting60702a cartridge parameter. The cartridge parameter can be a staple height of staples stored in the rows of staple cavities60531,60532of the end effector60502, for example. In addition, the process60700includes selecting60703a radio-frequency (RF) energy treatment for sealing the tissue based on the cartridge parameter and the tissue parameter. The process60700may utilize the RF energy phase to compensate for a discrepancy between a tissue thickness of a tissue grasped by the end effector60502, for example, and a staple height of the cartridge60530, for example. The discrepancy may arise when the grasped tissue is thicker than can be successfully accommodated by the staple height of the cartridge60530. In such instances, the RF energy phase can be utilized to thin the grasped tissue—through warming or drying out beyond an RF zone of the end effector60502and into a tissue stapling zone of the end effector60502—to yield a tissue thickness that can be successfully accommodated by the staple height of the cartridge60530. In other embodiments, the discrepancy between the tissue thickness and the staple height may arise when the grasped tissue is thinner than can be successfully stapled the cartridge60530due to the staple height being too tall. Consequently, the formed staples may not be able to apply sufficient compression to effectively seal the tissue. In such instances, the RF energy phase can be adjusted to expand a thermal spread through the tissue beyond the RF zone, and into the stapling to support energy sealing of tissue portions where staples will be too tall to effectively seal the tissue. Alternatively, in instances where thermal spread beyond the RF zone may reduce the thickness of the grasped tissue below what can be successfully stapled, the RF energy phase can be adjusted to minimize, or prevent, a thermal spread beyond the RF zone. In various instances, adjusting the thermal spread can be achieved by adjusting one or more parameters of the RF energy phase such as, for example, power level and/or activation time of the RF energy. In certain instances, adjusting parameters of the RF energy phase can be applied to individual segmented electrodes, or subsets of segmented electrodes, of the electrode assemblies60526,60527,60536,60537. In certain instances, the tissue thickness can be determined based on tissue impedance, for example. As described supra, the control circuit760can be configured to determine tissue impedance by causing the RF energy source794to pass one or more sub-therapeutic signals through the grasped tissue, utilizing for example the electrode assemblies60526,60527,60536,60536. The tissue thickness can then be determined based on a correlation between tissue impedance and tissue thickness, which can be stored in a storage medium such as, for example, the memory circuit86006. The correlation can be stored in any suitable form including a table, equation, or database, for example. In other embodiments, the tissue thickness can be determined by measuring a gap between the cartridge60530and the anvil60520abutting the grasped tissue. The gap can be measured by one or more of the sensors788, for example, and is representative of the tissue thickness. In certain instances, staple height, and other parameters of the cartridge60530can be stored in a storage medium such as, for example, a memory circuit, which can locally reside on, or within, the cartridge60530. The control circuit760can be configured to interrogate the storage medium of the cartridge605030to detect60702the cartridge parameter. In certain embodiments, the stapling phase of a hybrid tissue treatment cycle may be utilized to mitigate, counterbalance, compensate for, and/or offset defects in the RF energy phase, for example.FIG.207is a logic flow diagram of a process60710depicting a control program or a logic configuration for cooperatively applying the RF energy phase and the stapling phase to tissue portions of a tissue grasped by an end effector60502, for example, in a hybrid tissue treatment cycle. In various instances, the process60710can be implemented by any suitable surgical instrument such as, for example, surgical instruments1000,60000including any suitable end effector such as, for example, end effectors1300,60002,60502. However, for brevity, the following description of the process60710will focus on its implementation in the surgical instrument60000and the end effector60502, for example. In certain instances, the memory68008stores program instructions that, when executed by the processor68002, cause the processor68002to perform one or more aspects of the process60710. In the illustrated example, the process60710includes applying60711a therapeutic energy to a tissue grasped by an end effector60502, for example, to seal the tissue in an RF phase of a hybrid tissue treatment cycle. The control circuit760can be configured to cause the RF energy source794to activate segmented electrodes of one or more of the electrode assemblies60526,60527,60536,60536to apply the therapeutic energy to one or more tissue portions of the grasped tissue, in accordance with predetermined parameters of the hybrid tissue treatment cycle. Further to the above, the process60710includes detecting60712a tissue sealing inconsistency in the grasped tissue. The tissue sealing inconsistency can be an inadequate tissue seal due, for example, to a short circuit, which can result from the presence of a previously-fired staple. In certain examples, the control circuit760can be configured to cause the RF energy source794to pass one or more interrogation signals, which can be in the form of sub-therapeutic signals, through different tissue portions of the grasped tissue to detect inconsistencies in the tissue seal. The sub-therapeutic signals can be passed between pairs of segmented electrodes of the electrode assemblies60526,60527,60536,60536, for example. Tissue impedance of the different tissue portions can be determined following the RF energy phase. Since an inadequate tissue seal comprises different tissue impedance characteristics than those associated with an adequate seal, detecting tissue seal inconsistencies in the tissue portions can be achieved by comparing determined tissue impedance of such portions to a predetermined threshold, for example. Further to the above, the process60700may include adjusting60713a stapling parameter to compensate for the tissue sealing inconsistencies. In certain instances, adjusting the stapling parameter includes adjusting a tissue gap between the cartridge60530and an anvil60520. In certain instances, adjusting the stapling parameter includes adjusting a tissue compression of the grasped tissue, or a closure load of the end effector, for example. The control circuit760may be configured to cause a motor assembly to increase or decrease the closure load applied to the end effector by a closure driver such as, for example, the I-beam764, or closure drive3800in instances where closure and firing are driven separately. In certain instances, adjusting the stapling parameter includes adjusting a staple height of formed staples of the cartridge60530. In certain instances, adjusting the stapling parameter includes adjusting a firing speed for fine tuning the formed-staple height. The control circuit760may be configured to cause a motor assembly to increase or decrease the speed of a firing driver (e.g. I-beam764) to adjust the formed-staple height to compensate for the tissue sealing inconsistencies. In one example, the control circuit760can be configured to detect an inadequate seal in a first tissue portion between segmented electrodes60536a,60526a, for example, based on a comparison of the first tissue impedance to a predetermined threshold, or threshold range. The first tissue impedance can be measured by passing a first sub-therapeutic signal between the segmented electrodes60536b,60526c. Further, the control circuit760can be also configured to detect an adequate seal in a second tissue portion between segmented electrodes60536b,60526c, for example, based on a comparison of the second tissue impedance to the predetermined threshold, or threshold range. The second tissue impedance can be measured by passing a second sub-therapeutic signal between the segmented electrodes60536b,60526c. Furthermore, the control circuit760can be configured to select a firing speed of the firing driver (e.g. I-beam) in a tissue portion based on adequacy of the tissue seal in the tissue portion. Accordingly, the control circuit760can be configured to select a first firing speed of the firing driver (e.g. I-beam) in the first tissue portion with the inadequate tissue seal, and a second firing speed of the firing driver (e.g. I-beam) in the second tissue portion with the adequate tissue seal, wherein the first firing speed is less than the second firing speed, for example. In certain instances, the control circuit760can be configured to pause firing of the staple at a tissue portion with an inadequate tissue seal. In various aspects, a hybrid tissue treatment cycle can be applied to discrete tissue portions of a tissue grasped by an end effector60502by alternating between the RF energy phase and the stapling phase. The RF energy phase may lead the stapling phase to avoid circuit shorting conditions, which may occur if there are staples in the tissue during application of the RF energy phase. In other words, the stapling phase may follow the RF energy phase. In certain instances, the RF energy is applied to a proximal tissue portion, for example a tissue portion between the electrode assemblies60536a,60526a. Then, staples are fired from rows of staple cavities60221,60222into the proximal tissue portion by advancing the firing driver through the first tissue portion. The firing driver is then paused until the RF energy is applied to a proximal tissue portion, for example a tissue portion between the electrode assemblies60536b,60526b. Following application of the RF energy to the second tissue portion, the movement of the firing driver is reactivated to advance the firing driver through the second tissue portion thereby firing staples from rows of staple cavities60231,60232into the second tissue portion. Alternating between the RF phase and the stapling phase can be repeated for additional tissue portions until all the tissue portions of the grasped tissue are treated. Referring now toFIGS.208-210, a surgical instrument60000′ is configured to seal tissue using a combination of energy and stapling modalities or phases. The surgical instrument60000′ is similar in many respects to other surgical instruments such as, for example, the surgical instruments1000,60000, which are not repeated herein for brevity. For example, the surgical instrument60000′ includes an end effector60002′, the articulation assembly60008, the shaft assembly60004, and the housing assembly60006. Further to the above, the surgical instrument60000′ mainly differs from the surgical instrument60000in the electrical wiring associated with the electrode assembly60036. The surgical instrument60000′ comprises electrical wiring that defines two separate RF return paths60801,60802for the electrode assembly60036, while in the surgical instrument60000comprises electrical wiring that defines a single RF return path60801for the electrode assembly60036. For brevity, the following description focuses on the dual RF return paths60801,60802of the surgical instrument60000′. In the illustrated example, the staple cartridge60030′ comprises a proximal electrical contact60803define in a proximal wall of the staple cartridge60030′. A leaf-spring contact60804is connected to the proximal electrical contact60803, when the staple cartridge60030′ is properly inserted into the cartridge channel60040of the end effector60002′, as best illustrated inFIG.208. Additional wiring extends proximally from the leaf-spring contact60804to connect the electrical assembly60036to proximal electronics such as, for example, the control circuit760and/or the RF energy source794. Further to the above, the RF return path60801extends proximally from the electrode assembly60036, from the flex circuit60041, and penetrates the cartridge deck60047terminating at the proximal electrical contact60803. Similarly, the RF return path60802extends proximally from the electrode assembly60036, from the flex circuit60041, and penetrates the cartridge deck60047terminating at the proximal electrical contact60803. However, the he RF return path60802comprises a gap60805configured to be bridged by an isolated return pad of anvil60020′ of the end effector60002′, when the end effector60002′ is in a closed, or partially-closed, configuration, as illustrated inFIG.209. Accordingly, the RF return path60802remains open until the gap60508is bridged by the isolated return pad of the anvil60020′. In certain instances, the RF return paths60801,60802are utilized simultaneously, which ensures adequate connections through redundancy. In other instances, the RF return paths60801,60802define separate electrical pathways for separately connecting first and second electrical elements of the end effector600, respectively, to proximal electronics such as, for example, the RF energy source794and/or the control circuit760. In such instances, the first electrical elements, connected via the first RF return path60801, can be activated while the anvil60020′ remains in an open, or partially open, configuration, while the second electrical elements, connected via the second RF return path60802, can only be activated while the anvil60020′ remains in the closed configuration, as illustrated inFIG.210. FIG.211is a logic flow diagram of a process60850depicting a control program or logic configuration for cooperatively controlling application of a therapeutic signal to a tissue grasped by an end effector (e.g. end effector60502) and controlling a function of the end effector. The function includes at least one of an articulation of the end effector, a rotation of the end effector, a closure of the end effector about the tissue, and a firing of the staples into the tissue. In various instances, the process60850can be implemented by any suitable RF energy source (e.g. RF energy source794) and any suitable surgical instrument such as, for example, surgical instruments1000,60000that include any suitable end effector such as, for example, end effectors1300,60002,60502. However, for brevity, the following description of the process60850will focus on its implementation in a surgical system that includes the RF energy source794, the surgical instrument60000, and the end effector60502, for example. As described supra, the end effector60502is configured to grasp tissue in a closure motion of one, or both, of the jaws of the end effector60502. Further, the end effector60502is also configured to apply a tissue treatment cycle to the grasped tissue. The tissue treatment cycle includes an RF energy phase where the RF energy source794is configured to cause a therapeutic signal to be passed through the tissue to seal the tissue, and a stapling phase where staples are deployed into the tissue from a cartridge60530in a firing stroke. In the illustrated example, the process60850includes receiving60851a communication signal from the RF energy source794indicative of a deficiency in an application of the therapeutic signal to the grasped tissue, and adjusting60852a function of the end effector60502based on the communication signal to address the deficiency. The function includes at least one of an articulation of the end effector, a rotation of the end effector, a closure of the end effector about the tissue, and a firing of the staples into the tissue. The deficiency may, for example, be a power insufficiency to complete an effective tissue seal of grasped tissue via the therapeutic signal. The power insufficiency may result from an inadequacy of pressure applied to the tissue by the jaws of the end effector60502. Inadequate pressure may change the amount of fluid in the grasped tissue, which can change tissue impedance to a level that hinders a proper transfer of the therapeutic signal through the grasped tissue, by changing the power required to complete an effective seal beyond the safe capabilities of the RF energy source794. The RF energy source794may detect the power insufficiency based on impedance of the grasped tissue, for example. As described elsewhere herein in greater detail, the RF energy source794can measure tissue impedance of tissue portions between opposite segmented electrodes of the electrode assemblies60526,60527,50536,50536. Tissue impedance can then be compared to a threshold to determine whether sufficient power is available for an effective tissue seal. The threshold can be stored in a storage medium such as, for example, a memory circuit. In certain instances, the comparison can be performed by a processing unit at the RF energy source794. A communication signal can then be sent to the control circuit760to communicate the result of the comparison. In other instances, the communication signal may represent the value of the measured tissue impedance. In such instances, the comparison is performed by the control circuit760, and the threshold can be stored in the memory circuit68008, for example. In any event, if power insufficiency is detected, the control circuit760can be configured to adjust60852on or more function of the end effector60502to change the pressure applied onto the tissue by the jaws, which changes fluid levels in the grasped tissue, which changes the tissue impedance. If60853the change in tissue impedance addresses the deficiency, the control circuit760authorities application60804of the therapeutic signal to the tissue. In at least one example, various aspects of the process60850can be executed via the control circuit760. In certain instances, the memory68008stores program instructions that, when executed by the processor68002, cause the processor68002to perform one or more aspects of the process60800such as, for example, adjusting60852a function of the end effector60502. The control circuit760may cause one or more motor assemblies to change a degree of articulation and/or rotation of the end effector60502to adjust the pressure applied by the end effector60502onto the grasped tissue to address60853the deficiency. Additionally, or alternatively, the control circuit760may cause a motor assembly to move one or both of the jaws of the end effector60502to adjust a drive force of a closure drive (e.g. I-beam764, closure drive3800), which adjusts the clamp pressure applied by the end effector60502onto the grasped tissue, to address60853the deficiency. Additionally, or alternatively, the control circuit760may a motor assembly to adjust a parameter of motion of the I-beam764to address60853the deficiency. Referring primarily toFIG.212, in certain instances, the deficiency to be addressed can be in the end effector function rather than the application of the therapeutic signal. In one example, the deficiency can be a power insufficiency to perform the end effector function. As described supra, end effector functions are driven by one or more motor assemblies that can be powered by a local energy source such as, for example, the energy source762(FIG.163) which can be in the form of a battery, for example. A power insufficiency may result where a charge level of the local energy source762is less than the power requirement to complete one or more of the end effector functions, for example FIG.212is another logic flow diagram of a process60900depicting a control program or logic configuration for cooperatively controlling application of a therapeutic signal to a tissue grasped by an end effector (e.g. end effector60502) and controlling a function of the end effector in an application of a tissue treatment cycle. More specifically, the process60900is focused on addressing a deficiency in an end effector function such as, for example, a local power insufficiency to complete an end effector closure. In various instances, the process60850can be implemented by any suitable RF energy source (e.g. RF energy source794) and any suitable surgical instrument such as, for example, surgical instruments1000,60000that include any suitable end effector such as, for example, end effectors1300,60002,60502. However, for brevity, the following description of the process60850will focus on its implementation in a surgical system that includes the RF energy source794, the surgical instrument60000, and the end effector60502, for example. In certain instances, the memory68008stores program instructions that, when executed by the processor68002, cause the processor68002to perform one or more aspects of the process60900. In the illustrated example, the process60900is relevant to an application of an RF energy to a tissue grasped by the end effector60502below an optimal closure threshold due to a power insufficiency to complete the closure of the end effector60502. The RF energy source794can be configured to cause one or more of the electrode assemblies60526,60527,60536,60536to apply the RF energy to the tissue by passing a therapeutic signal through the tissue. The process60900includes detecting60901a charge level of a local energy source (e.g. energy source794) configured to supply power to a motor assembly configured to effect closure of the end effector60502. The process60900further includes adjusting60902a parameter of the therapeutic signal based on the charge level of the local energy source. In certain instances, the control circuit760is configured to monitor a charge level of the local energy source762. In at least one example, the control circuit760employs a charge meter to monitor the charge level. If the charge level is below a predetermined threshold associated with an end effector function such as, for example, closure of the end effector, the control circuit may cause the RF energy source794to adjust a parameter of the therapeutic signal to compensate for the inability of the motor assembly responsible for the closure of the end effector to fully complete the closure function. In certain instances, the adjusted parameter of the therapeutic signal is power. The control circuit760can be configured to cause the RF energy source794to increase a power level of the therapeutic signal, for example, in response to determining that a charge level of the local energy source is below the predetermined threshold. Energy Sealing, Sensing, and Algorithms Therefor The surgical instrument1000, as described above in connection withFIGS.1-13, may be adapted and configured for energy sealing and sensing under the control of various algorithm as described hereinbelow in connection withFIGS.213-233. The surgical instrument1000comprises an energy delivery system1900and control circuit configured to seal tissue with electrical energy and to execute algorithms for sensing short circuits in the end effector1300jaws1310,1320. In particular, the following description is directed generally to algorithms for detecting RF short circuits in the end effector1300jaws1310,1320, determining system RF power levels (including deactivation) from the energy delivery system1900, determining which portions of an electrode1925in the end effector1300jaws1310,1320are energized, and indicating to a user, by way of the display1190in communication with the control system of the surgical instrument1000, the status of the surgical instrument1000and an explanation of what is occurring within the surgical instrument1000. Prior to describing the various algorithms that may be executed by the control circuit of the surgical instrument1000, the description first turns to an explanation of the electrical/electronic operating environment in which the algorithms are executed for energy sealing and sensing operations. FIG.213illustrates a control system40600for the surgical instrument1000described in connection withFIGS.1-13comprising a plurality of motors40602,40606which can be activated to perform various functions, in accordance with at least one aspect of the present disclosure. It will be appreciated that the surgical instrument1000may comprise electronic control circuits having different configurations without limiting the scope of the present disclosure in this context. In certain instances, a first motor40602can be activated to perform a first function and a second motor40606can be activated to perform a second function, and so on. In certain instances, the plurality of motors40602,40606of the control system40600can be individually activated to cause firing, closure, and/or articulation motions in the end effector. The firing, closure, and/or articulation motions can be transmitted to the end effector through a shaft assembly, for example. In certain aspects, the control system40600may include a firing motor40602. The firing motor40602may be operably coupled to a firing motor drive assembly40604which can be configured to transmit firing motions, generated by the motor40602to the end effector, in particular to displace the knife element. In certain instances, the firing motions generated by the motor40602may cause the staples to be deployed from the staple cartridge into tissue grasped by the end effector and/or the cutting edge of the knife element to be advanced to cut the grasped tissue, for example. The knife element may be retracted by reversing the direction of the motor40602. In certain aspects, the control system40600may include an articulation motor40606, for example. The articulation motor40606may be operably coupled to an articulation motor drive assembly40608, which can be configured to transmit articulation motions generated by the articulation motor40606to the end effector. In certain instances, the articulation motions may cause the end effector to articulate relative to the shaft, for example. As described above, the control system40600may include a plurality of motors which may be configured to perform various independent functions. In certain aspects, the plurality of motors40602,40606of the control system40600can be individually or separately activated to perform one or more functions while the other motors remain inactive. For example, the articulation motor40606can be activated to cause the end effector to be articulated while the firing motor40602remains inactive. Alternatively, the firing motor40602can be activated to fire the plurality of staples, and/or to advance the cutting edge, while the articulation motor40606remains inactive. Each of the motors40602,40606may comprise a torque sensor to measure the output torque on the shaft of the motor. The force on an end effector may be sensed in any conventional manner, such as by force sensors on the outer sides of the jaws or by a torque sensor for the motor actuating the jaws. In various aspects, as illustrated inFIG.213, the control system40600may comprise a first motor driver40626to drive the firing motor40602and a second motor driver40632to drive the articulation motor40606. In other aspects, a single motor driver may be employed to drive the firing and articulation motors40602,40606. In one aspect, the motor drivers40626,40632each may comprise one or more H-Bridge field effect transistors (FETs). The firing motor driver40626may modulate the power transmitted from a power source40628to the firing motor40602based on input from a microcontroller40578(the “controller” or “control circuit”), for example. In certain instances, the microcontroller40578can be employed to determine the current drawn by the firing motor40602, for example, while the firing motor40602is coupled to microcontroller40578, as described above. In certain aspects, the microcontroller40578may include a microprocessor40622(the “processor”) and one or more non-transitory computer-readable mediums or memory units40624(the “memory”) coupled the processor40622. In certain aspects, the memory40624may store various program instructions, which when executed may cause the processor40622to perform a plurality of functions and/or calculations described herein. In certain aspects, one or more of the memory units40624may be coupled to the processor40622, for example. In certain instances, the power source40628can be employed to supply power to the microcontroller40578, for example. In certain instances, the power source40628may comprise a battery (or “battery pack” or “power pack”), such as a lithium-ion battery, for example. In certain instances, the battery pack may be configured to be releasably mounted to a handle for supplying power to the control system40600. A number of battery cells connected in series may be used as the power source40628. In certain instances, the power source628may be replaceable and/or rechargeable, for example. In various instances, the processor40622may control the firing motor driver40626to control the position, direction of rotation, and/or velocity of the firing motor40602. Similarly, the processor40622may control the articulation motor driver40632to control the position, direction of rotation, and/or velocity of the articulation motor40606. In certain aspects, the processor40622can signal the motor drivers40626,40632to stop and/or disable the firing or articulation motor40602,40606coupled to the processor40622. It should be understood that the term “processor” as used herein includes any suitable microprocessor, microcontroller, or other basic computing device that incorporates the functions of a computer's central processing unit (CPU) on an integrated circuit or, at most, a few integrated circuits. The processor40622is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory40624, and provides results as output. It is an example of sequential digital logic, as it has internal memory. Processors40622operate on numbers and symbols represented in the binary numeral system. In other aspects, the controller40578or control circuit may comprise analog or digital circuits such programmable logic devices (PLD), field programmable gate arrays (FPGA), discrete logic, or other hardware circuits, software, and/or firmware, or other machine executable instructions to perform the functions explained in the following description. In one aspect, the processor40622may be any single-core or multicore processor such as those known under the trade name ARM Cortex by Texas Instruments. In certain aspects, the microcontroller40578may be an LM 4F230H5QR, available from Texas Instruments, for example. In at least one example, the Texas Instruments LM4F230H5QR is an ARM Cortex-M4F Processor Core comprising an on-chip memory of 256 KB single-cycle flash memory, or other non-volatile memory, up to 40 MHz, a prefetch buffer to improve performance above 40 MHz, a 32 KB single-cycle SRAM, an internal ROM loaded with StellarisWare® software, a 2 KB EEPROM, one or more PWM modules, one or more QEI analogs, one or more 12-bit ADCs with 12 analog input channels, among other features that are readily available for the product datasheet. Other microcontrollers may be readily substituted for use with the control system40600. Accordingly, the present disclosure should not be limited in this context. In certain aspects, the memory40624may include program instructions for controlling each of the firing and articulation motors40602,40606of the control system40600that are couplable to the processor40622. For example, the memory40624may include program instructions for controlling the firing motor40602and the articulation motor40606. Such program instructions may cause the processor40622to control the firing, closure, and articulation functions in accordance with inputs from algorithms or control programs of the surgical instrument or tool. In certain aspects, the controller40578may be coupled to an RF generator40574and a plurality of electrodes40500disposed in the end effector via a multiplexer40576. The RF generator40574is configured to supply bipolar or monopolar RF energy either individually or in combination. In one aspect, the RF generator40574is configured to drive the segmented RF electrodes40500with an in-series current limiting element Z within the distal portion of the instrument for each electrode40500. The RF generator40574may be configured to sense a short circuit between the electrode40550and the return path40510by monitoring the output current, voltage, power, and impedance characteristics of the segmented electrode40500. In one aspect, the RF generator40574may be configured to actively limit the current through or redirect the current around a shorted electrode40500when a short is detected. This function also may be accomplished by the controller40578in combination with a switching element such as the multiplexer40576. The redirection or current limiting function may be controlled by the RF generator40574in response to a detected short circuit or electrode40500irregularity. If the RF generator40574is equipped with a display, the RF generator40574can display information to the user when a restricted electrode40500has been detected and the restriction on current may be removed when sensing of the short circuit is removed. The RF generator40574can engage the sensing and limiting functions as the tissue welding operation continues or at the start of a tissue welding operation. In one aspect, the RF generator40574may be a stand alone generator. In another aspect, the RF generator40574may be contained within the surgical instrument housing. In one aspect, the RF generator may be configured to adapt the energy modality (monopolar/bipolar) RF applied to the end effector1300of the surgical instrument1000based on shorting or other tissue resistance, impedance, or irregularity. The RF monopolar/bipolar energy modality may be adapted by the RF generator40574or by the controller40578in combination with a switching element such as the multiplexer40576. In one aspect, the present disclosure provides a dual energy mode RF endocutter surgical instrument1000configured to apply monopolar or bipolar RF energy. Further, the RF generator40574can be configured to adjust the power level and percentage of each monopolar or bipolar RF energy modality based on tissue impedance conditions detected either by the RF generator40574or the controller40578. The energy modality adjustment function may comprise switching between bipolar and monopolar RF energy modalities, blending the bipolar and monopolar RF energy modalities, or blending of certain electrode segments405001-4. In one aspect, the independently controlled electrode segments405001-4could be switched together as a group or as individual electrode segment-by-segment405001-4. With reference now also toFIG.239, in various aspects, the dual energy mode RF endocutter surgical instrument1000may be employed with staples44300that have variable electrical conductivity along their body. In one aspect, the variable electrical conductivity staple44300may comprise a portion of the staple44300such as the deformable legs44304,44306that are electrically conductive and a portion of the staple44300such as the crown44320that has a different electrical conductivity from the deformable legs44304,44306. The electrical conductivity of the staple44300may vary based on its geometry or material composition such that when the staple44300is grasped in a shorting condition between the RF electrode40500and the return path40510of a dual mode RF energy/stapling combination surgical instrument1000, the variable conductivity of the staple44300may be advantageously exploited to prevent the staple44300from shorting one electrode40500to the other. In one aspect, the conductivity of the staple44300may be based on the temperature of the staple44300, current through the staple44300, or a portion of the staple44300having a high dielectric breakdown coefficient. In one aspect, the surgical staple44300for a combination energy stapler surgical instrument1000comprises a crown44302defining a base44301and first and second deformable legs44304,44306extending from the each end of the base44301. A first electrically conductive material disposed on at least a first portion of the base44301and a second electrically conductive material disposed on at least a second portion of the base44301. The electrical conductivity of the first electrically conductive material is different from the electrical conductivity of the second electrically conductive material. In one aspect, the first and second electrically conductive materials are the same and the electrical conductivity varies based on different geometries of the first and second electrically conductive materials deposited on the first and second portions of the base44301. In one aspect, the first and second electrically conductive materials have different compositions and the electrical conductivity varies based on the different compositions of the first and second electrically conductive materials deposited on the first and second portions of the base44301. In one aspect, the first and second electrically conductive materials have similar geometries and different material compositions to provide different electrical conductivities. With reference back toFIG.213, in other aspects, the controller40578may be coupled to one or more mechanisms and/or sensors to alert the processor40622to the program instructions that should be used in a particular setting. For example, the sensors may alert the processor40622to use the program instructions associated with firing, closing, and articulating the end effector. In one aspect, the memory40624may store executable instructions to cause the processor40622to detect RF shorting in the end effector by monitoring one or more than one electrode406234. In another aspect, the memory40624may store executable instructions to cause the processor40622to determine RF power level (including deactivation). In other aspects, memory40624may store executable instructions to cause the processor40622to determine which portions of the electrodes40500are energized and indicate to the user of why and what is happening via a display40625coupled to the controller40578. In one aspect, the memory40624may comprise executable instructions that when executed cause the processor40622to detect short circuits in the end effector and predict the electrode40500by the controller40578and in response adapt the RF energy path of the RF energy generated by the RF generator40574. In one aspect, the electrodes40500may be segmented RF electrodes with an in-series current limiting element within the distal portion of the control system40600for each electrode. Aspects of segmented electrodes are described hereinbelow in connection withFIGS.214-217. In other aspects, the memory40624may store executable instructions to cause the processor40622to sense a short circuit between an electrode40500and the return path40510. In other aspects, the memory40624may store executable instructions that when executed cause the processor40622to actively limit the current through or redirect the current around a shorted electrode40500when a short circuit is detected. In various aspects, the redirection or current limiting is performed by the controller40578or the RF generator40574in response to a detected short circuit or electrode40500irregularity. In various aspects, the controller40578can detect when an electrode40574has been restricted and can display that information to the user via the display40625. In various aspects, the current restriction function may be removed when the sensing of the short circuit is removed. In various aspects, the sensing and limiting functions can be engaged as the tissue welding process continues or at the start of a tissue welding process. In various aspects, prior to applying therapeutic energy, the controller40578may apply a pre-sealing energy cycle to the electrode40500array at a lower than therapeutic level to provide an initial screen to scan for short circuits between the electrodes40500or between the electrodes40500and the return electrode40510. The multiplexer40576may cycle through the electrode40500array by sending low level signals out to determine if faults are present. This could be reported back to the RF generator405774. A contained system could then exclude channels where faults are or shorts are present and cycle through the remaining channels without the RF generator40574needing to adapt its output to the surgical instrument1000. In one aspect, coils may be employed as miniature metal detectors to determine presence of existing staples in a proposed energy path. In this example, the system is passive and does not pass an electric current through the tissue. In certain aspects, the controller40578may be coupled to various sensors. The sensors may comprise position sensors which can be employed to sense the position of switches, for example. Accordingly, the processor40622may use the program instructions associated with firing the knife of the end effector upon detecting, through the sensors, for example, that the switch is in the first position; the processor40622may use the program instructions associated with closing the anvil upon detecting, through the sensors for example, that the switch is in the second position; and the processor40622may use the program instructions associated with articulating the end effector upon detecting, through the sensors for example, that the switch is in the third or fourth position. Additional sensors include, without limitation, arc detection sensors to measure AC ripple on the base RF waveform and to measure current Δdi/dt. Other sensors include optical detectors and/or laparoscopic cameras to monitor specific frequencies or wavelengths in the visible, infrared (IR), or other portions of the electromagnetic spectrum. In one aspects, sensors to detect negative incremental resistance and RF arc temperature may be coupled to the controller40578. Other sensors, include environmental sensors to measure humidity, atmospheric pressure, temperature, or combinations thereof. FIG.214shows a jaw40524of an end effector for the surgical instrument1000described inFIGS.1-13where the electrode1925shown inFIG.6is configured with multiple pairs of segmented RF electrodes40500disposed on a circuit board40570, or other type of suitable substrate, on a lower surface of the jaw40524(i.e., the surface of the jaw40524facing tissue during operation), in accordance with at least one aspect of the present disclosure. The various pairs of segmented RF electrodes40500are energized by an RF source (or generator)40574. A multiplexer40576may distribute the RF energy to the various pairs of segmented RF electrodes40500as desired under the control of a controller40578. According to various aspects, the RF source40574, the multiplexer40576, and the controller40578may be located in the energy delivery system1900extending through the shaft1200and the articulation joint1400and into the end effector1300of the surgical instrument1000as described in connection withFIGS.1and6. The RF energy is coupled between the electrodes40500and a return path40510back to the RF generator40574. In the example of the pairs of segmented electrodes40500shown inFIG.214, the circuit board40570may comprise multiple layers that provide electrical connections between the multiplexer40576and the various pairs of segmented electrodes40500. For example, the circuit board40570may comprise multiple layers providing connections to the pairs of segmented electrodes40500. In one example, an upper most layer may provide connections to the most proximate pairs of segmented electrodes40500; a middle layer may provide connections to middle pairs of segmented electrodes40500; and a lowest layer may provide connections to most distal pairs of segmented electrodes40500. The pairs of segmented electrodes40500configuration, however, is not limited in this context. FIG.215illustrate a multi-layer circuit board40570, in accordance with at least one aspect of the present disclosure.FIG.215shows a cross-sectional end view of the jaw40524. The circuit board40570, adjacent to staple pockets50584, comprises three conducting layers405801-3, having insulating layers405821-4therebetween, showing how the various layers405801-3may be stacked to connect back to the multiplexer40576. An advantage of having multiple RF electrodes40500in the end effector1300, as shown inFIG.6, is that, in the case of a metal staple line or other electrically conductive object left in the tissue from a previous instrument firing or surgical procedure that may cause a short circuit of the electrodes40500, such a short situation could be detected by the RF generator40574, the multiplexer40576, and/or the controller40578, and the energy may be modulated in a manner appropriate for the short circuit or adaptation of the energy path in response. FIG.216shows segmented electrodes40500on either side of the knife slot40516in the jaw40524have different lengths, in accordance with at least one aspect of the present disclosure. In the illustrated example, there are four co-linear segmented electrodes, but the most distal electrodes405001,405002are 10 mm in length, and the two proximate electrodes405003,405004are 20 mm in length. Having shorter distal electrodes405001,405002may provide the advantage of concentrating the therapeutic energy applied to the tissue. FIG.217is a cross-sectional view of an end effector comprising a plurality of segmented electrodes40500, in accordance with at least one aspect of the present disclosure. As shown in the example ofFIG.217, the segmented electrodes40500are disposed on the upper jaw40524(or anvil) of the end effector. In the illustrated example, the active segmented electrodes40500are positioned adjacent the knife slot40516. A metal anvil portion of the jaw40524may serve as the return electrode. Insulators40504, which may be made of ceramic, insulate the segmented electrodes40500from the metallic jaw40524. FIG.218shows a jaw40524of an end effector for the surgical instrument1000described inFIGS.1-13and214where multiple pairs of segmented RF electrodes40500include a series current limiting element Z within the distal portion of the end effector for each electrode, in accordance with at least one aspect of the present disclosure. The current limiting element Z is shown schematically in series with the multiplexer40576, but may be disposed on the circuit board40570where the electrode elements are disposed. Accordingly, the controller40578or the RF generator40574may be configured to sense a short between an electrode40500and the return path40510and actively limit the current through or redirect the current around the shorted electrode40500when a short circuit is detected. In one aspect, the redirection or current limiting is done by the controller40578electronics in the surgical instrument1000(FIGS.1-13) or the RF generator40574in response to a detected short circuit or electrode irregularity. In one aspect, the controller40578or RF generator40574can detect when an electrode40500has been restricted and can display that information to the user on the display40625(FIG.213). In one aspect, the restriction on current is removed when the sensing of the short circuit is removed. In one aspect, the sensing and limiting can be engaged as the tissue welding process continues or at the start of the tissue welding process. RF Shorting Detection Methods and Systems Therefor With reference toFIGS.1-13, the present disclosure now turns to a description of systems and methods for detecting RF shorting in the jaws1310,1320of the end effector1300and determining the RF power level (including deactivation), and which portions of the electrode1925are energized and indicating to the user of why and what is happening via the display1190. The systems and methods comprise detecting RF short circuiting in the jaws1310,1320of the end effector1300employing algorithmic differentiation and detecting RF arching by monitoring the surgical instrument1000. In one general aspect, a system and method comprises detecting an RF short circuit in the end effector1300by algorithmic differentiation between low impedance tissue grasped in the jaws1310,1320of the end effector1300and a metallic short circuit between the electrode1925and the return path defined by the return electrode1590. A detection/warning to surgeons of shorting risk is provided to the user via the display1190. Algorithms utilized low power exploratory pulses prior to firing and can differentiate clips/staples and acceptable compared to unacceptable amounts of metal in the jaws1310,1320. With reference also toFIGS.213-218above and219-234hereinbelow, the systems and methods for detecting RF short circuiting in the jaws1310,1320of the end effector1300employing algorithmic differentiation and detecting RF arching by monitoring the surgical instrument1000, will be described in connection with the control system40600for the surgical instrument1000shown inFIG.213and the segmented electrodes40500described in connection withFIGS.213-218and the graphical representations shown inFIGS.219-232. Finally, the method will be further described in connection with the method41900,42000described in connection withFIGS.233and234. In one general aspect, the present disclosure provides a system40600and method41900for detecting and predicting shorting of the of the electrode1925and/or the segmented electrode40500by the controller40578electronics and adaptation of the energy path in response thereto. In one aspect, the segmented RF electrodes40500may comprises an in-series current limiting element Z (FIG.218) within the distal portion of the instrument1000jaw40524for each electrode405001-4, among others, for example. In another aspect, the controller40578is configured to sense a short between the electrode1925and the return path defined by the return electrode1590or the electrode40500and the return path40510. In yet another aspect, the controller40578may be configured to actively limit the current through or redirect the current around a shorted electrode1925,40500, when a short is detected. In yet another aspect, the controller40578or RF generator40574may be configured to redirect or limit the current though a shorted electrode element in response to a detected short or electrode irregularity. In yet another aspect, the controller40578may be configured to detect when an electrode1925,40500has been restricted and can display that information to the user via the display1190,40625. Further, in yet another aspect, the controller40578may be configured to remove the restriction on current when the sensing of the short is removed. Further, in yet another aspect, the controller40578may be configured to engage short circuit sensing and current limiting as the tissue welding process continues or at the start of the tissue welding process. Algorithmic Differentiation With reference toFIGS.1-13and213-228D, the present disclosure now turns to a description of one aspect of algorithmic differentiation between low impedance tissue conditions and a metallic short between the electrode1925and the return path electrode1590or the electrode40500and the return path40510. Upon detecting a short circuit, the controller40578provides a warning to the surgeon of shorting risk. The algorithms utilize low power exploratory pulses prior to firing, differentiate clips/staples, acceptable compared to unacceptable amounts of metal, and detection of metal in the jaws1320,40524causing energy control adjustments. FIGS.219-222illustrate various graphical representations of low power exploratory pulse waveforms41000, e.g., current, power, voltage, and impedance, applied to an electrodes1925or a segmented electrode40500to illustrate the algorithmic differentiation between low impedance tissue conditions and a metallic short between electrodes1925,40500and the return path electrodes1590,40510.FIG.219is a graphical representation of exploratory pulse waveforms41000applied by the RF generator40574under control of the controller40578to an electrode1925,40500to detect a metallic object shorting the electrode1925,40500and the return path electrode1590,40510, in accordance with at least one aspect of the present disclosure. In particular,FIG.219depicts the application of low power exploratory pulse waveforms41000prior to firing or activating RF sealing energy in liver tissue that includes a metallic staple located in the field causing a short between an electrode1925,40500and a return path electrode1590,40510. The exploratory pulse waveforms41000comprise a pulsed current waveform41002, a pulsed power waveform41004, a pulsed voltage waveform41006, and a pulsed impedance waveform41008measured between the electrode1925,40500and the return path electrode1590,40510before and during a shorting event, which is shown in the detailed view inFIG.220. FIG.220is a detailed view of the exploratory pulse waveforms41000applied to an electrode1925,40500during a shorting event, in accordance with at least one aspect of the present disclosure. The exploratory pulse waveforms4100are applied prior to firing or delivering therapeutic RF energy to seal tissue grasped between the jaws1320(40524),1310of the end effector1300. As shown, during the shorting event period, the pulsed current waveform41002increases to a maximum value (e.g., imax≥3 A) and at the same time the pulsed power waveform41004decreases to a minimum value (e.g., pmin≤2 W), the pulsed voltage waveform41006decreases to a minimum value (e.g., νmin≤0.6 V), and the pulsed impedance waveform41008decreases to a minimum value (e.g., Zmin≤0.2 Ohms). In one aspect, the shorting detection algorithm applies exploratory energy pulses monitors the values of the pulsed waveforms41002,41004,41006,41008and compares them to predetermined values to determine if a short circuit is present between the jaws1320(40524),1310of the end effector1300. The algorithm, then determines whether the exploratory pulse waveforms41000are due to a short circuit or low impedance tissue grasped between the jaws1320(40524),1310of the end effector1300. FIG.221is a graphical representations of exploratory pulse waveforms41010applied to an electrode1925,40500prior to firing or delivering therapeutic RF energy to seal tissue grasped between the jaws1320(40524),1310of the end effector1300, in accordance with at least one aspect of the present disclosure. The exploratory pulse waveforms41010are applied to low impedance tissue without the presence of a short circuit between the electrode1925,40500and the return electrode1590,40510. The low impedance tissue exploratory pulse waveforms41010comprise a current waveform41012, a power waveform41014, a voltage waveform41016, and an impedance waveform41018. FIG.222is a detailed view depicting the pulsed impedance waveform41018applied to tissue having an impedance of approximately 2Ω, in accordance with at least one aspect of the present disclosure. It has been determined that low tissue impedance is approximately in the range of 1Ω to 3Ω. As shown inFIG.221, the value of the exploratory pulsed current waveform41012applied the low impedance tissue increases to about 2.8 A while the exploratory pulsed voltage waveform41016drops to about 5V and the exploratory pulsed power waveform41014drops to about 20 W. Testing of the RF generator40574identified tissue impedance Z<1Ω as a short circuit compared to low impedance tissue impedance, which has been identified as ˜2Ω and in the range of 1Ω to 3Ω. With reference toFIGS.213-222, in one aspect, the present disclosure provides a method of detecting shorting in a jaw50524of an end effector prior to initiating a tissue sealing (welding) cycle. Accordingly, the memory40624stores executable instructions that when executed by the processor40622cause the processor40622control the RF generator40574to generate a series of pre-cycle exploratory pulses as shown inFIGS.219-222to determine whether there is a short in the jaw40524of the end effector or whether tissue in contact with the jaw40524has a low impedance. Under the control of the processor40622, the RF generator40574delivers pulses of non-therapeutic RF energy levels to the electrodes405001located at the distal end (nose) of the jaw40524at the initiation of an energy activation cycle. The nose pulse(s) is not detectable to a surgeon and it is part of the activation sequence. In one aspect, the pulse/detection period may be selected in the range of 0.1 to 1.0 seconds in duration. In other aspects, the pulse/detection period is less than 0.5 seconds in duration. In other aspects, under control of the processor40622the RF generator40574generates nose pulse(s) with non-therapeutic energy level at the initiation of energy activation to provide shorting detection specificity. In one aspect, the RF generator40574generates a single pulse that is applied to all active/return electrodes40500simultaneously. In another aspect, the RF generator40574generates multiple pulses, each with different combinations of segments of active/return electrodes40500to enable extremely specific targeting of active/return electrodes40500when in therapeutic mode in order to seal around a detected short. Still with reference toFIGS.213-222, in one aspect, the present disclosure provides a method of detecting shorting in a jaw50524of an end effector during the tissue sealing cycle. Detection of shorts in the jaw50524within the tissue sealing cycle may be necessary when staples/clips are protected by the tissue and shorting may not occur until the tissue sealing cycle has begun. Such tissue protected staples/clips are not detectable using the pre sealing cycle nose pulse as described above. In this aspect, the controller40578of the control system40600is configured to react in real time to manage activation of one or more electrode segments405001-405004. Accordingly, the memory40624may store executable instructions that when executed by the processor40622cause the processor40622to control the RF generator40574to generate and apply a continuous non-pulsed energy to the electrodes40500and determines real time rate changes or real time level thresholds of the current, power, voltage, and/or impedance. In one aspect, the processor40622is configured to detect decreased voltage, impedance, and/or power. In another aspect, the processor40622is configured to detect increased current. In various other aspect, the memory40624may store executable instructions that when executed by the processor40622cause the processor40622to execute alternative detection techniques which are not based on energy flow. In one aspect, segmented thermocouples may be located at each active and/or return electrode40500location and the processor40622is configured to read the temperature of each thermocouple and to employ a heat signature at a location of a segmented electrode40500to determine the presence of a short. In another alternative detection aspect of the present disclosure, a coil pickup may be located at each active and/or return electrode40500location and the processor40622is configured to detect a magnetic field induced from electric output by the electrode40500segment. The coils may be employed as miniature metal detectors to determine the presence of existing staples in a proposed energy path. The coil detection system is passive and does include passing a current through the tissue to enable detection of a short. In another alternative detection aspect of the present disclosure, a single frequency detector is employed to sense if a short has occurred in the jaw40524. In one aspect, the single frequency detector comprises two coils to detect a very low frequency (VLF) inductance or resistance. In another aspect, the single frequency detector employs pulse induction (PI) utilizing one coil for both transmit and receive functions and is good in saline environments. In yet another aspect, the single frequency detector comprises two coils and is configured to detect beat frequency oscillations (BFO). In another alternative detection aspect of the present disclosure, a multiple frequency detector is employed to determine to sense if a short has occurred in the jaw40524. In one aspect, the multiple frequency detector may be configured short depth frequency (shallow target) or long depth frequency (deep target). In another alternative detection aspect of the present disclosure, a balance device may be employed to remove unwanted signal of background environment (tissue, fluids). In one aspect, the balance device may employ manual or automatic adjustments. In automatic adjustments, the balance device determines the best balance settings. In one aspect, the balance device provides tracking adjustments where the balance device continuously adjusts based on current conditions of surrounding environment. In another alternative detection aspect of the present disclosure, staple material may be selected for specific identification of shorts. In one aspect, the staple material composition may be made unique to the manufacturer. This technique may be employed to identify specific competitor staples. In another alternative detection aspect of the present disclosure, coils may be positioned horizontal and/or vertical where gains/losses in signal depend upon the position of a foreign object relative to the coil. In one aspect, each coil is positioned surrounding each electrode40500on the deck or circuit board40570. In another aspect, the coils may be positioned/molded into a plastic cartridge wall surrounding the electrode40500. In various other aspect, the memory40624may store executable instructions that when executed by the processor40622cause the processor40622to predict a short, prior to full shorting, by interrogating data in a pulsed energy application. In one aspect, the pulsing may enable prediction of shorting verse reaction to shorting. In one aspect, the energy profile may be a pulsed application rather than a continuous application of energy. Pulsing may provide an extra layer of information than non-pulsed energy techniques based on needing to ramp up energy repeatedly throughout a cycle. FIGS.223-228Dillustrate several examples of energy activation in liver tissue that includes a metallic staple in the field as described in connection withFIGS.219-222.FIG.223is a graphical representation of a first example of exploratory pulse waveforms41100applied by the RF generator40574under control of the controller40578to an electrode1925,40500to detect a metallic object shorting the electrode1925,40500and the return path electrode1590,40510. FIG.223depicts the application of a first example of low power exploratory pulse waveforms41100prior to firing or activating RF sealing energy in liver tissue that includes a metallic staple located in the field causing a short between an electrode1925,40500and a return path electrode1590,40510, in accordance with at least one aspect of the present disclosure. The exploratory pulse waveforms41100comprise a pulsed current waveform41102, a pulsed power waveform41104, a pulsed voltage waveform41106, and a pulsed impedance waveform41108measured between the electrode1925,40500and the return path electrode1590,40510before and during a shorting event. FIG.224Ais a detailed view of the impedance waveform41108component of the exploratory pulse waveforms41100during a transition to a short circuit between the electrode1925,40500and the return path electrode1590,40510, in accordance with at least one aspect of the present disclosure. As shown, prior to the shorting event, the impedance41108decreases prior to reaching the short circuit impedance41110during the shorting event. FIG.224Bis a detailed view of the power waveform41104component of the exploratory pulse waveforms41100during a transition to a short circuit between the electrode1925,40500and the return path electrode1590,40510, in accordance with at least one aspect of the present disclosure. As shown, prior to the shorting event, the power41104decreases prior to reaching the short circuit power41112during the shorting event. FIG.224Cis a detailed view of the voltage waveform41106component of the exploratory pulse waveforms41100during a transition to a short circuit between the electrode1925,40500and the return path electrode1590,40510, in accordance with at least one aspect of the present disclosure. As shown, prior to the shorting event, the voltage41106decreases prior to reaching the short circuit voltage41114during the shorting event. FIG.224Dis a detailed view of the current waveform41102component of the exploratory pulse waveforms41100during a transition to a short circuit between the electrode1925,40500and the return path electrode1590,40510, in accordance with at least one aspect of the present disclosure. As shown, prior to the shorting event, the current41102increases prior to reaching the short circuit current41116during the shorting event. FIG.225depicts the application of a second example of low power exploratory pulse waveforms41200prior to firing or activating RF sealing energy in liver tissue that includes a metallic staple located in the field causing a short between an electrode1925,40500and a return path electrode1590,40510, in accordance with at least one aspect of the present disclosure. The exploratory pulse waveforms41200comprise a pulsed current waveform41202, a pulsed power waveform41204, a pulsed voltage waveform41206, and a pulsed impedance waveform41208measured between the electrode1925,40500and the return path electrode1590,40510before and during a shorting event. FIG.226Ais a detailed view of the impedance waveform41208component of the exploratory pulse waveforms41200during a transition to a short circuit between the electrode1925,40500and the return path electrode1590,40510, in accordance with at least one aspect of the present disclosure. As shown, prior to the shorting event, the impedance41208decreases prior to reaching the short circuit impedance41210during the shorting event. FIG.226Bis a detailed view of the power waveform41204component of the exploratory pulse waveforms41200during a transition to a short circuit between the electrode1925,40500and the return path electrode1590,40510, in accordance with at least one aspect of the present disclosure. As shown, prior to the shorting event, the power41204decreases prior to reaching the short circuit power41212during the shorting event. FIG.226Cis a detailed view of the voltage waveform41206component of the exploratory pulse waveforms41200during a transition to a short circuit between the electrode1925,40500and the return path electrode1590,40510, in accordance with at least one aspect of the present disclosure. As shown, prior to the shorting event, the voltage41206decreases prior to reaching the short circuit voltage41214during the shorting event. FIG.226Dis a detailed view of the current waveform41202component of the exploratory pulse waveforms41200during a transition to a short circuit between the electrode1925,40500and the return path electrode1590,40510, in accordance with at least one aspect of the present disclosure. As shown, prior to the shorting event, the current41202increases prior to reaching the short circuit current41216during the shorting event. FIG.227depicts the application of a second example of low power exploratory pulse waveforms41300prior to firing or activating RF sealing energy in liver tissue that includes a metallic staple located in the field causing a short between an electrode1925,40500and a return path electrode1590,40510, in accordance with at least one aspect of the present disclosure. The exploratory pulse waveforms41200comprise a pulsed current waveform41302, a pulsed power waveform41304, a pulsed voltage waveform41306, and a pulsed impedance waveform41308measured between the electrode1925,40500and the return path electrode1590,40510before and during a shorting event. FIG.228Ais a detailed view of the impedance waveform41308component of the exploratory pulse waveforms41300during a transition to a short circuit between the electrode1925,40500and the return path electrode1590,40510, in accordance with at least one aspect of the present disclosure. As shown, prior to the shorting event, the impedance41308decreases prior to reaching the short circuit impedance41310during the shorting event. FIG.228Bis a detailed view of the power waveform41304component of the exploratory pulse waveforms41300during a transition to a short circuit between the electrode1925,40500and the return path electrode1590,40510, in accordance with at least one aspect of the present disclosure. As shown, prior to the shorting event, the power41304increases prior to reaching the short circuit power41312during the shorting event. FIG.228Cis a detailed view of the voltage waveform41306component of the exploratory pulse waveforms41300during a transition to a short circuit between the electrode1925,40500and the return path electrode1590,40510, in accordance with at least one aspect of the present disclosure. As shown, prior to the shorting event, the voltage41306decreases prior to reaching the short circuit voltage41314during the shorting event. FIG.228Dis a detailed view of the current waveform41302component of the exploratory pulse waveforms41300during a transition to a short circuit between the electrode1925,40500and the return path electrode1590,40510. As shown, prior to the shorting event, the current41302increases prior to reaching the short circuit current41316during the shorting event. In one aspect, the exploratory waveforms define a ramp. The controller40578may be configured to compare an actual pulse ramp to a specified pulse ramp. Each pulse of energy application has a specified pulse ramp. The controller40578may be configured to identify a short circuit risk when the actual pulse ramp is different from the specified pulse ramp for a predefined voltage, current, or impedance exploratory waveform. In one aspect, the controller40578may be configured to compare present pulse data to pulse data of previous pulses including for example, moving average, etc. As previously described, the controller40578may identify a short circuit risk by detecting a decrease in voltage, impedance, or power or detecting an increase in current. In one aspect, the controller40578may be configured to monitor the electrode40500or segments of the electrode405001-4to determine a level of shorting risk based on predicted or actual shorting conditions in the jaws1310,1320(40524) of the end effector1300. The controller40578may be configured to differentiate clips/staples from a short circuit condition, acceptable in contrast to unacceptable amounts of metal, and the location of metallic objects in the jaws1310,1320(40524) of the end effector1300. A higher risk of shorting may be determined by the controller40578by differentiating between clips, staples, and unknown metallic objects in the sealing zone of the jaws1310,1320(40524) of the end effector1300. The controller40578, however, may be configured to differentiate a clip by measuring the resistance where a clip has a lower resistance (micro ohms) based on the amount of metal in the clip compared to the staple. The controller40578may be configured to measure electrode405001-4segment temperature where the clip most likely has a lower temperature, based on lower resistance, compared to a staple. In one aspect, segmented thermocouples may be incorporated in the jaws of the end effector to measure the temperature at different locations in the jaws. In one aspect, a clip impedance ramp is different than a staple impedance ramp and the controller40578may be configured to determine the difference. For example, clips and staples have different inductive or capacitive reactance that can be monitored by the controller40578to determine risk of shorting. In one aspect, the controller40578may be configured to detect a short circuit between two or more adjacent segments of the segmented electrode405001-4to be indicative of a clip or multiple staples. In other aspects, the controller40578may be configured to detect a short circuit distributed over more than 25% of the segments in a segmented electrode405001-4. A lower risk may be determined by the controller40578when the RF sealing pathway is defined through a non-optimal path, i.e., opposed sealing path compared to offset sealing path. In other aspects, switching between bipolar to monopolar sealing presents a lower risk of shorting. Accordingly, the controller40578may be configured to assess a lower risk of shorting when the surgical instrument switches from bipolar to monopolar sealing. Also, a staple located in the sealing zone presents a lower risk of shorting as well as the presence of known metallic objects in the sealing zone. Also, lower risk may be determined when the staples are made of a unique metal for a particular RF/endocutter device such as the surgical instrument1000. In such instance, the controller40578may be configured to differentiate how the surgical instrument1000responds to the presence of a known unique metal. Upon detection of a short circuit condition in the jaws1310,1320(40524) of the end effector1300, the controller40578may configured to output a warning to surgeons of a shorting risk though one or more than one user interfaces that may be audible, visual, tactile, or combinations thereof. In one aspect, the controller40578may output a warning on the display40625. In addition to communicating the presence of a shorting risk to the surgeon, the controller40578may be configured to identify and inform of the location of the risk, the risk level, device changes in response to risk, and/or provide recommendations for surgeon action. In other aspects, the controller40578may be configured to communicate aggregated information to a simple yes/no, good/bad, ready to fire, etc. type concise communication. In other aspects, the controller40578may be configured to not communicate to the surgeon, but rather manage the shorting events or potential risks of sorting appropriately. RF Arcing Detection In one aspect, the controller40578may be configured to monitor the electrode40500or segments of the electrode405001-4to detect RF arcing. Arc detection may be implemented by the controller40578monitoring the operation and functionality of the surgical instrument1000. Potential arc detection/risk factors include excessive AC ripple on the base RF waveform. Accordingly, in one aspect, the controller40578or the RF generator40574may be configured to monitor excessive AC ripple on the base RF waveform. In another aspect, the controller40578may be configured to measure the RF current and determine the potential arc detection/risk by measuring an increasing current Δdi/dt. In addition to or alternatively, the controller40578may be configured to monitor corona glow by employing an optical detector to make optical measurements. In one aspect, optical measurements may be made using a laparoscopic camera and monitoring specific frequencies in the visible, infrared (IR), or other portions of the electromagnetic spectrum. In one aspect, such optical measurement techniques may be integration into a surgical hub architecture. Other RF arcing detection techniques include, without limitation, configuring the controller40578to detect negative incremental resistance, which causes the electrical resistance to decrease as the arc temperature increases. Other environmental factors that may cause or exacerbate RF arcing that the controller40578may be taken into account in the configuration of the controller40578include monitoring a variety of sensors coupled to the controller to measure humidity, atmospheric pressure, temperature, or combinations thereof. Potential measurement tools include probes on the surgical instrument1000or the end effector1300, other devices or measurements taken in the operating room or coupled to a surgical hub, laparoscopes, etc. The description now turns to several plots that depict electrical parameters associated with RF arcing.FIG.229is a graphical depiction41400of impedance41402, voltage41406, and current41408versus time (t), in accordance with at least one aspect of the present disclosure. At the time of the arc point41410an excess di/dt (current versus time) results in a steep rising current41408versus time (t) slope41412and a rapid decrease in impedance −dZ/dt (negative impedance versus time) results in a steep falling impedance41402versus time (t) slope41414. This may be referred to as a negative incremental resistance that produces an electric arc. In one aspect, as previously described, the controller40578may be configured to monitor either the current41408versus time (t) slope41412(di/dt), the impedance41402versus time slope41414(−dZ/dt), or a combination thereof to predict the occurrence of the risk of an electric arc. FIG.230is a graphical depiction41500of an electric arcing charge41505across a 1.8 cm gap in a 0.8 cm2area relative to current41502and voltage41506waveforms, in accordance with at least one aspect of the present disclosure. As shown, the current41502rapidly increases until the arcing charge41505starts to rise. The voltage41506rises rapidly and the current41502drops. After the electric arc discharge, the voltage41506drops rapidly and the current41502decreases to zero. FIG.231is a graphical depiction41600of electric discharge regimes as a function of voltage versus current, where current (Amps) is along the horizontal axis and voltage (Volts) is along the vertical axis, in accordance with at least one aspect of the present disclosure. As shown, the electric discharge starts in the dark regime41620, transitions to the glow discharge regime41622, and then transitions to the arc discharge regime41624. In the dark discharge regime41620, the voltage curve transitions from background ionization41602through a saturation regime41604to a corona region61608. In the glow discharge regime41622, the voltage41610drops after it reaches a breakdown voltage point and transitions from a normal glow41618region to an abnormal glow region. The voltage41612rises until it transitions into the arc discharge regime41624, at which point there is glow-to-arc transition where the voltage41614rapidly drops and creates first a non-thermal arc and then a thermal arc. FIG.232is a graphical depiction41700of power (Watts) as a function of impedance (Ohms) of various tissue types, in accordance with at least one aspect of the present disclosure. As current41702is applied into low impedance tissue, the power41704is relatively low. As the tissue impedance starts to increase, the power41704increases until the impedance reaches ˜1000 Ohms. At which point the power41704starts to decrease exponentially with increasing tissue impedance. As shown, the tissue impedance of prostate tissue41706in nonconductive solution is in the range of ˜10 Ohms to ˜1500 Ohms as energy is applied. The impedance of liver and muscle tissue41708is in the range of ˜500 Ohms to ˜1900 Ohms as energy is applied. The impedance of bowel tissue41710is in the range of ˜1200 Ohms to ˜2400 Ohms as energy is applied. The impedance of gall bladder tissue41712is in the range of ˜1700 to ˜3000 Ohms as energy is applied. The impedance of mesentery momentum tissue41714is in the range of ˜2600 Ohms to ˜3600 Ohms as energy is applied. The impedance of fat, scar, or adhesion tissue41716is in the range of ˜3000 Ohms to ˜4000 Ohms as energy is applied. In various aspects, the controller40578may be configured to detect an electric arc discharge in real time. Multiple frequencies may be employed to detect the tissue state as indicated inFIG.232. Real time detection of electric arc discharges in real time can speed up diagnostics and can be configured to provide real time diagnostics in a tissue environment (pressure, moisture content) for different tissues as shown inFIG.232, for example. FIG.233is a logic flow diagram of a method41900of detecting a short circuit in the jaws1310,1320(40524) of an end effector1300of a surgical instrument1000(seeFIGS.1-6and213-218), in accordance with at least one aspect of the present disclosure. With reference also toFIGS.6and213-218, in accordance with the method41900, the memory40624may store a set of executable instructions that when executed cause to processor40622to execute the method41900. In accordance with the method41900, the processor40622causes the RF generator40574to apply41902a sub-therapeutic electrical signal to an electrode40500located in the jaw1320(40524) of the end effector1300to detect a short circuit. If the jaw1320comprises a single longitudinal electrode1925, the RF generator40574can apply the sub-therapeutic electrical signal directly to the single longitudinal electrode1925. If the jaw40524comprises a segmented electrode40500, the processor40622selects one of the segmented electrodes40500through the multiplexer40576and then causes the RF generator40574to apply the sub-therapeutic electrical signal to the selected electrode40500. It should be appreciated that the sub-therapeutic electrical signal is a signal used to detect a short circuit between the electrode1925(40500) and the return electrode1590(40510) without causing any therapeutic effects on the tissue grasped in the end effector1300. In accordance with the method41900, based on the signals received by the processor40622after applying the sub-therapeutic electrical signals, the processor40622determines41904if the electrode1925(40500) is shorted to the return electrode1590(40510). If the electrode1925(40500) is not shorted, the method41900continues along the NO path and the processor40622causes the RF generator40574to apply41918therapeutic RF electrical energy to the electrode1925(40500). In contrast, if the electrode1925(40500) is shorted, the method41900continues along the YES path and the processor40622modifies the electrical current through the shorted electrode1925(40500). In one aspect, the processor40622limits41906the electrical current through the shorted electrode1925(40500). In one aspect, if the jaw1320comprises a single electrode1925, the processor40622causes the RF generator40574to limit41906the output current. In another aspect, if the jaw40524comprises a segmented electrode40500, the processor40622through the multiplexer40576selectively redirects41908the current path around the shorted electrode40500through the current limiter Z coupled to a distal electrode segment. In either case, the processor40622causes the display40625to display41910information about the detected shorted electrode1925(40500) to the surgeon or other members of the surgical team. In accordance with the method41900, the processor40622determines41912if the electrode1925(40500) is still shorted. If the electrode1925(40500) is still shorted, the method41900continues along the YES path and the processor40622continues to limit41906or redirect41908the electrical current applied to the shorted electrode1925(40500). If the electrode1925(40500) is no longer shorted, the method41900continues along the NO branch and the processor40622removes41914the electrical current limit restriction through the electrode1925(40500) or removes41918the electrical current redirection around the electrode1925(40500). The processor40622then causes the RF generator40574to apply41918therapeutic RF electrical energy to the electrode1925(40500). FIG.234is a logic flow diagram of a method42000of detecting a short circuit in the jaws1310,1320(40524) of an end effector1300of a surgical instrument1000(seeFIGS.1-6and213-218), in accordance with at least one aspect of the present disclosure. With reference also toFIGS.6and213-218, in accordance with the method42000, the memory40624may store a set of executable instructions that when executed cause to processor40622to execute the method42000. In accordance with the method42000, the processor40622causes the multiplexer40576to select42002an electrode405001-4in an array of segmented electrodes40500. The processor40622causes the RF generator40574to apply42004a sub-therapeutic electrical signal to the selected electrode405001-4located in the jaw40524of the end effector1300to detect a short circuit. In accordance with the method42000, based on the signals received by the processor40622after applying the sub-therapeutic electrical signals, the processor40622determines42006if the selected electrode405001-4is shorted to the return electrode40510. If the selected electrode405001-4is not shorted, the method42000continues along the NO path and the processor40622selects42008the next electrode405001-4in the array of electrodes40500through the multiplexer40576and then tests the newly selected electrode405001-4until all segmented electrodes405001-4have been tested for shorts. If any one of the selected electrodes405001-4is shorted, the method42000continues along the YES path and the processor40622modifies the electrical current through the shorted electrode405001-4. In one aspect, the processor40622selectively modifies the current through the shorted electrode405001-4through the multiplexer40576either to limit42010the electrical current through the shorted selected electrode405001-4or redirect42012electrical current around the shorted electrode405001-4. the causes the RF generator40574to apply41918therapeutic RF electrical energy to the selected electrode405001-4. In one aspect, the processor40622through the multiplexer40576redirects41908the current path around the shorted electrode40500through the current limiter Z coupled to a distal electrode segment. In either case, the processor40622causes the display40625to display42014information about the detected shorted electrode405001-4to the surgeon or other members of the surgical team. In accordance with the method42000, the processor40622determines42016if the selected electrode405001-4is still shorted. If the selected electrode405001-4is still shorted, the method42000continues along the YES path and the processor40622continues to limit42010or redirect42012the electrical current to the shorted selected electrode405001-4. If the selected electrode405001-4is no longer shorted, the method42000continues along the NO branch and the processor40622removes42018the electrical current limit restriction through the selected electrode405001-4or removes42020the electrical current redirection around the selected electrode405001-4. The processor40622then causes the RF generator40574to apply42022therapeutic RF electrical energy to the selected electrode405001-4. In various aspects, the processor40622determines42006if the electrode1925(40500) is shorted to the return electrode1590(40510) as described inFIG.233or determines42006if the selected electrode405001-4is shorted to the return electrode40510as described inFIG.234using the techniques described inFIGS.219-228D. For example, with reference toFIGS.219-222, the processor40622may be configured to distinguish a shorted electrode from low impedance tissue. In one aspect, with reference to219-220, the processor40622controls the RF generator40574to apply a sequence of exploratory pulse waveforms41000to the electrode1925(40500). In one aspect, the exploratory pulses are applied prior to firing or delivering therapeutic RF energy to seal tissue grasped between the jaws1320(40524),1310of the end effector1300. The processor40622monitors the exploratory waveforms41000and determines that an electrode1925(40500) is shorted when the pulsed current waveform41002increases to a maximum value (e.g., imax≥3 A) and at the same time the pulsed power waveform41004decreases to a minimum value (e.g., pmin≤2 W), the pulsed voltage waveform41006decreases to a minimum value (e.g., νmin≤0.6 V), and the pulsed impedance waveform41008decreases to a minimum value less than 1 Ohm (e.g., Zmin≤0.2 Ohms). The processor40622distinguishes a shorted electrode1925(40500) from low impedance tissue as described in connection withFIGS.221-222when the tissue impedance is approximately in the range of 1Ω to 3Ω. As shown inFIG.221, the value of the exploratory pulsed current waveform41012applied the low impedance tissue increases to about 2.8 A while the exploratory pulsed voltage waveform41016drops to about 5V and the exploratory pulsed power waveform41014drops to about 20 W. Testing of the RF generator40574identified tissue impedance Z<1Ω as a short circuit compared to low impedance tissue impedance, which has been identified as ˜2Ω and in the range of 1Ω to 3Ω. Dual Energy Modality Combination Surgical Instrument With reference toFIGS.1-6and213-218, in one aspect, the surgical instrument1000may be configured as a dual energy modality combination energy device with switchable/blendable energy modalities. The controller40578is configured to adapt energy modality (monopolar/bipolar) RF endocutter based on shorting or other tissue resistance, impedance, or irregularity. In one aspect, the surgical instrument1000RF endocutter may be configured to apply monopolar or bipolar RF energy to the segmented electrodes40500. In one aspect, the power level and percentage of each energy modality may be adjusted based on the low resistance tissue conditions detected by the controller40578. As previously described, the controller40578comprises a memory40624storing executable instructions and a processor40622configured to execute the instructions and adjust energy modalities. In one aspect, the processor40622may be configured to interchange the energy modalities from bipolar to monopolar RF, blend the two energy modalities, or blend certain electrode segments405001-4only. In one aspect, the processor40622may be configured to independently control the electrode segments405001-4to switch together as a group or as individual electrode segments405001-4on a segment-by-segment basis. As described in connection withFIGS.213-228D, the controller40578may be configured to determine the difference between a shorting event and a low impendence tissue event for use in controlling or switching the energy modalities. In one aspect, the controller40578may be configured to blend or switch the energy modality to prevent shorting of the segmented electrodes405001-4by metallic contact. In one aspect, the controller40578may be configured to determine that a segment of an electrode405001-4is shorted by the presence of a metallic staple within the jaws1310,1320(40524) of the end effector1300or by the jaws1310,1320(40524) physically touching one another. Upon determining that there is a shorting event, the controller40578first blends the energy modality and then switches the energy modality from bipolar to monopolar if blending the energy modalities does not resolve the short circuit event below an arcing discharge (e.g., sparking) threshold as described above in connection withFIGS.229-232. In one aspect, for example, if the controller40578determines that monopolar and bipolar return paths40510are open simultaneously, blending will not occur as desired because energy will take the path of least resistance, which may bypass the desired energy modality path. Therefore, the processor40622may be configured to selectively control the multiplexer40576to switch between monopolar/bipolar energy paths as necessary, such that the energy modality return paths are not open simultaneously. The processor40622can consider blending the energy modalities at the time in which active switching is occurring. In one aspect, the processor40622may alternate active switching (energy modality blending) between bipolar and monopolar in accordance with the following technique. During bipolar energization, the processor40622through the multiplexer40576opens the bipolar energy return path40510with all the electrodes405001-4turned on and any shorted electrodes405001-4turned off. During monopolar energization, the processor40622through the multiplexer40576opens the monopolar return path with only the shorted active electrode405001-4turned on. In another aspect, during monopolar energization, the processor40622through the multiplexer40576opens the monopolar return path with all electrodes405501-4turned on. In another aspect, the processor40622may be configured to adjust energy modality or balance based on sensed tissue impedance limit. The processor40622may be configured to sense a parameter of the tissue grasped within the jaws1310,1320(40524) of the end effector1300to interrogate if a conductive element or other metallic object is located within the tissue in the jaws1310,1320(40524). As discussed above in connection withFIGS.213-228D, the controller40578may be configured to apply several exploratory pulse waveforms of non-therapeutic energy to the electrodes405001-4during a pre-energy activation cycle. The exploratory pulses may be are applied prior to firing or delivering therapeutic RF energy to seal the tissue. The RF exploratory pulse waveforms may comprise multiple high frequency waves transmitted through the electrodes405001-4. The return signal may be employed to determine various tissue parameters including the type of cutting/coagulation desired such as electrosurgical cutting, fulguration, desiccation, or time based. In one aspect, the processor40622may employ the impedance readings to determine the tissue type as described above in connection withFIG.232. In one aspect, the initial power settings may be based on known tissue parameters and subsequent pow retting may be adapted based on measurements or readings of tissue impedance, for example. In one aspect, tissue parameters may be sensed utilizing ferroelectric ceramic materials. Ferroelectricity is a characteristic of certain materials that have a spontaneous electric polarization (P) that can be reversed by the application of an external electric field (E). Three examples of spontaneous electric polarization by ferroelectric ceramic materials are shown inFIGS.235-237.FIG.235shows a dielectric polarization plot41800where polarization (P) is a linear41802function of external electric field (E), in accordance with at least aspect of the present disclosure.FIG.236shows a paraelectric polarization plot41820where polarization (P) is a non-linear41822function of external electric field (E) exhibiting a sharp transition from negative to positive polarization at the origin, in accordance with at least aspect of the present disclosure.FIG.237shows ferroelectric polarization plot41840where polarization (P) is a non-linear41842function of external electric field (E) exhibiting hysteresis around the origin, in accordance with at least aspect of the present disclosure. Examples of ferroelectric ceramic materials include, barium titanate, ceramics incorporated with a metallic wire, or ceramic coatings applied on staples. Barium titanate is a ceramic with dielectric constant values as high as 7,000. Over a narrow temperature range, values as high as 15,000 are possible. FIG.238is logic flow diagram of a method43000of adapting energy modality due to a short circuit or tissue type grasped in the jaws1310,1320(40524) of an end effector1300of a surgical instrument1000, in accordance with at least one aspect of the present disclosure. With reference also toFIGS.6and213-218, in one aspect, the processor40622selects43002an electrode405001-4in an array of segmented electrodes40500through the multiplexer40576. During a pre-energy activation cycle, the processor40622causes the RF generator4074to apply43004a sub-therapeutic electrical signal to the selected electrode405001-4to differentiate between a shorted electrode and low impedance tissue grasped in the jaws1310,1320(40524) of the end effector1300. Based on a measured parameter received by the processor40622after applying the sub-therapeutic electrical signal, the processor40622determines43006if the selected electrode405001-4is shorted. In accordance with the method43000, if the selected electrode405001-4is shorted, the method43000proceeds along the YES path and the processor40622causes the RF generator40574to blend43008monopolar and bipolar RF energy. After a period of time of applying blended monopolar and bipolar RF energy, the processor40622determines43010if the selected electrode405001-4is still shorted. If the selected electrode405001-4is still shorted the method43000proceeds along the YES path and the processor40622switches43012the output energy of the RF generator40574between monopolar and bipolar RF energy through the multiplexer40576and continues determining43010if the selected electrode is still shorted. In accordance with the method43000, when the processor40622determines43006,43010that the selected electrode405001-4is no longer shorted, the method43000proceeds along the NO path and the processor40622senses43014parameters of tissue grasped within the jaws1310,1320(40524) of the end effector1300. As described above in connection withFIG.232, the processor40622determines43016the type of tissue based on the sensed tissue parameter such as impedance or other measured parameters. As described in connection withFIG.33, the tissue impedance of prostate tissue41706in nonconductive solution is in the range of ˜10 Ohms to ˜1500 Ohms as energy is applied. The impedance of liver and muscle tissue41708is in the range of ˜500 Ohms to ˜1900 Ohms as energy is applied. The impedance of bowel tissue41710is in the range of ˜1200 Ohms to ˜2400 Ohms as energy is applied. The impedance of gall bladder tissue41712is in the range of ˜1700 to ˜3000 Ohms as energy is applied. The impedance of mesentery momentum tissue41714is in the range of ˜2600 Ohms to ˜3600 Ohms as energy is applied. The impedance of fat, scar, or adhesion tissue41716is in the range of ˜3000 Ohms to ˜4000 Ohms as energy is applied. Once the type of tissue is determined43016, the processor40622determines443018a suitable procedure for cutting/coagulation based on the tissue type and applies43200the determined cutting/coagulation procedure to the tissue. Accordingly, during the execution of the method4300and the application of the RF monopolar or bipolar RF energy, the processor40622controls the power level and/or percentage of each energy modality and adjusts the power level and percentage of each energy modality based on the low resistance tissue conditions detected. The processor40622may adjust energy modality by switching between bipolar to monopolar, blending of the two energy modalities, or blending a subset of the electrode segments405001-4, In other aspects, the processor40622is configured to independently control the electrode segments405001-4to switch together as a group or as an individual segment-by-segment process. Controlled Reaction to RF Shorting from Previous Staple Line FIG.239illustrates a staple44300comprising a crown44302defining a base44301and deformable legs44304,44306extending from each end of the base44301, in accordance with at least one aspect of the present disclosure. Similar to the above, the staple cartridge recesses can be configured to guide and/or deform the legs44304,44306when they contact the stapler cartridge. In one aspect, the crown44302includes a material44303disposed on the base44301, where the material may be overmolded or coated onto the base44301. As discussed in greater detail below, the material44303can be comprised of a material such as, for example, an electrically insulative material, a material having variable electrical resistance that increases resistance as the staple44300become heated, or a variable resistance thermally sensitive material, each of which is described in detail hereinbelow. In at least one of these aspects, the material44303may be formed around a single continuous wire comprising base44301and deformable legs44304,44306. In other aspects, the deformable legs44304,44306can include separate deformable members embedded in a material44303. Further, in various aspects, the wire comprising the base44301can be deformed to provide the recesses and anvils described above. In one aspect, the controller40578may be configured for monitor a controlled reaction of the staple44300due to RF shorting from a previous staple line. In one aspect, the present disclosure provides a RF endocutter surgical instrument1000for use with staples44300that have variable electrical conductivity along their body and in one aspect along the crown44302or base44301portion of the crown44302. In one aspect the staple44300may comprise a portion having a first electrical conductivity and another portion having a second electrical conductivity, where the first and second electrical conductivities are different. In one aspect, the electrical conductivity of the staple44300may vary based on geometry or material aspects. For example, when the staple44300is grasped in a shorting condition between the RF electrode40524and the return path40510of a energy/stapling combination device such as the RF endocutter surgical instrument1000, the variable conductivity prevents the staple44300from shorting electrodes40500against each other. In various other aspects, the electrical conductivity of the staple44300may be based on the temperature of the staple44300, electrical current through the staple44300, or a portion of the staple44300, such as the base44301or other portion of the crown44302, having a high dielectric breakdown coefficient. In various aspects, the present disclosure provides various staple configurations to minimize the chance of shorting by modifying or adjusting the electrical conductivity of the staple44300. In one aspect, the staple44300may be configured such that a non-bendable crown44302portion of the staple44300is electrically insulated to minimize the likelihood that the next firing results in shorting while the end effector1300is clamped across a previously deployed staple44300embedded in the tissue. In one aspect, the non-bendable crown44302portion of the staple44300may be formed of an electrically insulative material or may comprise an absorbable polymer to minimize shorting. In other aspects, an absorbable insulating material may double as a driver to eliminate the driver in the cartridge stack of the end effector1300. In various aspects of the present disclosure, the crown4132portion of or the entire staple44300may comprise electrically insulative portions formed of electrically insulative materials or may comprise an electrically insulative material44303overmolded onto the base44301of the staple44300. In one aspect, the electrically insulative material44303may be overmolded over the crown44302, or base44301, of the staple44300. In one aspect, the electrically insulative material44303may be overmolded or applied to the staple44300in the form of a coating having a thickness in the range of 0.0005 inches to 0.0015 inches and typically about 0.001 inches. In one aspect, the staple44300may be overmolded onto the crown44302portion or base portion44301of the staple44300with a lactide and glycolide copolymer plus calcium stearate coating similar to the material known under the common name Vikryl. The thickness of the coating material44303may be in the range of 0.0005 inches to 0.0015 inches and typically about 0.001 inches. In various aspects of the present disclosure, the crown44302portion of the staple44300or the entire staple44300may be dipped or coated in a polyimide material44303such as, for example, a polyimide film known under the common name Kapton developed by DuPont. Polyimide provides high dielectric strength to resist shorts. Various polyimide materials44303that are suitable candidates for coating or dipping the staple44300are described in U.S. Pat. No. 6,686,437 titled MEDICAL IMPLANTS MADE OF WEAR-RESISTANT, HIGH-PERFORMANCE POLYIMIDE, PROCESS OF MAKING SAME AND MEDICAL USE OF SAME, which is herein incorporated by reference. Other polyimide materials for dipping or coating the staple44300include, without limitation, a polymer known under the common name Parylene C, which has a high dielectric strength of approximately 6800 V and may be applied by vapor deposition. In various aspects of the present disclosure, the crown44302portion, or base44301portion, of the staple44300or the entire staple44300may comprise ferroelectric ceramic materials44303. Ferroelectric materials44303may be characterized as having a spontaneous electric polarization that can be reversed by the application of an external electric field, as described inFIGS.235-237, for example. In one aspect, metal detector coils may be embedded in the jaw1310of the end effector1300that is opposed to the jaw1320(40524) comprising the electrodes1925,40500. In this configuration, the embedded metal detector coils may be energized to induce an electric field in the staple to cause a polarization change of the ferroelectric material. The polarization change of the ferroelectric material lowers the electrical conductivity of the staple44300and thereby prevent the staple44300from short circuiting. Other ferroelectric materials44303include, without limitation, barium titanate and lead zirconate titanate. Barium titanate is a ceramic material44303having dielectric constant values as high as approximately 7,000. Over a narrow temperature range, dielectric constant values as high as 15,000 may be achievable. In various aspects of the present disclosure, the crown44302portion, or the base44301portion, of or the entire staple44300may comprise a Polyisobutene material44303, a class of organic polymers prepared by polymerization of isobutene. Examples of Polyisobutene materials44303that may be employed are described in U.S. Pat. No. 8,927,660 titled CROSSLINKABLE POLYISOBUTYLENE-BASED POLYMERS AND MEDICAL DEVICES CONTAINING THE SAME, which is incorporated herein by reference. In various aspects, the present disclosure provides a staple44300made of a wire material having an electrical resistance that is temperature dependent such that electrical resistivity increases as its temperature increases to minimize shorting of staples from previous firings. Accordingly, when the staple wire is placed in a short circuit condition, its temperature increases. The increase in temperature increases the electrical resistivity of the staple wire. Accordingly, in one aspect, the staple44300may be characterized as a variable electrical resistance where the resistance increase as the temperature of the staple increases when the staple is under a short circuit condition. This characteristic may be realized by making the staple wire from a metal/material hybrid such as, for example, the materials used to make resistance temperature devices (RTDs) or any metal/material that employs the resistance/temperature relationship of metals. Accordingly, the variable electrical resistance staple may be made of a length of wire wrapped around a ceramic core, for example. The temperature resistive wire may be made of a material, such as platinum, nickel, or copper, for example. The temperature/resistance relationship of the material can be used to increase the electrical resistance of the staple44300as its temperature increases under a short circuit condition. The temperature resistive wire may be housed in a protective layer of material. In various aspects, the present disclosure provides a staple wire material that increases its electrical resistance based on the temperature of the staple wire to minimize shorting of staples from previous firings. Variable resistance thermally sensitive staples44300may be employed in the RF endocutter surgical instrument1000described herein. In one aspect, the temperature resistive wire material may be made of a metallic alloy which has a positive temperature coefficient where the electrical resistance increases as a function of temperature. Therefore, as the staple44300heats up under a short circuit condition, the electrical resistance of the staple wire increases to minimize the effects of a short circuit. In addition, the staple wire material has the material properties of staples. The staple wire material may be similar to a light bulb filament where the resistance to electrical current of the metal wire increases as the metal wire gets hotter so it does not short and melt. In one aspect, the staple wire may be a cobalt-nickel-chromium-molybdenum-tungsten-iron alloy, for example. The entire disclosures of U.S. Pat. No. 8,070,034, entitled SURGICAL STAPLER WITH ANGLED STAPLE BAYS, which issued on Dec. 6, 2011, U.S. Pat. No. 10,143,474, entitled SURGICAL STAPLER, which issued on Dec. 4, 2018, and U.S. Pat. No. 7,611,038, entitled DIRECTIONALLY BIASED STAPLE AND ANVIL ASSEMBLY FOR FORMING THE STAPLE, which issued on Nov. 3, 2009, are incorporated by reference herein. The entire disclosures of U.S. Pat. No. 8,424,735, entitled VARIABLE COMPRESSION SURGICAL FASTENER CARTRIDGE, which issued on Apr. 23, 2013, U.S. Pat. No. 7,722,610, entitled MULTIPLE COIL STAPLE AND STAPLE APPLIER, which issued on May 25, 2010, and U.S. Pat. No. 8,056,789, entitled STAPLE AND FEEDER BELT CONFIGURATIONS FOR SURGICAL STAPLER, which issued on Nov. 15, 2011, are incorporated by reference herein. The entire disclosure of U.S. Pat. No. 6,843,403, entitled SURGICAL CLAMPING, CUTTING AND STAPLING DEVICE, which issued on Jan. 18, 2005, is incorporated by reference herein. The entire disclosures of U.S. Pat. No. 8,070,034, entitled SURGICAL STAPLER WITH ANGLED STAPLE BAYS, which issued on Dec. 6, 2011, U.S. Pat. No. 10,143,474, entitled SURGICAL STAPLER, which issued on Dec. 4, 2018, and U.S. Pat. No. 7,611,038, entitled DIRECTIONALLY BIASED STAPLE AND ANVIL ASSEMBLY FOR FORMING THE STAPLE, which issued on Nov. 3, 2009, are incorporated by reference herein. The entire disclosures of U.S. Pat. No. 8,424,735, entitled VARIABLE COMPRESSION SURGICAL FASTENER CARTRIDGE, which issued on Apr. 23, 2013, U.S. Pat. No. 7,722,610, entitled MULTIPLE COIL STAPLE AND STAPLE APPLIER, which issued on May 25, 2010, and U.S. Pat. No. 8,056,789, entitled STAPLE AND FEEDER BELT CONFIGURATIONS FOR SURGICAL STAPLER, which issued on Nov. 15, 2011, are incorporated by reference herein. The entire disclosure of U.S. Pat. No. 6,843,403, entitled SURGICAL CLAMPING, CUTTING AND STAPLING DEVICE, which issued on Jan. 18, 2005, is incorporated by reference herein. The surgical instrument systems described herein have been described in connection with the deployment and deformation of staples; however, the embodiments described herein are not so limited. Various embodiments are envisioned which deploy fasteners other than staples, such as clamps or tacks, for example. Moreover, various embodiments are envisioned which utilize any suitable means for sealing tissue. For instance, an end effector in accordance with various embodiments can comprise electrodes configured to heat and seal the tissue. Also, for instance, an end effector in accordance with certain embodiments can apply vibrational energy to seal the tissue. The entire disclosures of:U.S. Pat. No. 5,403,312, entitled ELECTROSURGICAL HEMOSTATIC DEVICE, which issued on Apr. 4, 1995;U.S. Pat. No. 7,000,818, entitled SURGICAL STAPLING INSTRUMENT HAVING SEPARATE DISTINCT CLOSING AND FIRING SYSTEMS, which issued on Feb. 21, 2006;U.S. Pat. No. 7,422,139, entitled MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITH TACTILE POSITION FEEDBACK, which issued on Sep. 9, 2008;U.S. Pat. No. 7,464,849, entitled ELECTRO-MECHANICAL SURGICAL INSTRUMENT WITH CLOSURE SYSTEM AND ANVIL ALIGNMENT COMPONENTS, which issued on Dec. 16, 2008;U.S. Pat. No. 7,670,334, entitled SURGICAL INSTRUMENT HAVING AN ARTICULATING END EFFECTOR, which issued on Mar. 2, 2010;U.S. Pat. No. 7,753,245, entitled SURGICAL STAPLING INSTRUMENTS, which issued on Jul. 13, 2010;U.S. Pat. No. 8,393,514, entitled SELECTIVELY ORIENTABLE IMPLANTABLE FASTENER CARTRIDGE, which issued on Mar. 12, 2013;U.S. patent application Ser. No. 11/343,803, entitled SURGICAL INSTRUMENT HAVING RECORDING CAPABILITIES, now U.S. Pat. No. 7,845,537;U.S. patent application Ser. No. 12/031,573, entitled SURGICAL CUTTING AND FASTENING INSTRUMENT HAVING RF ELECTRODES, filed Feb. 14, 2008;U.S. patent application Ser. No. 12/031,873, entitled END EFFECTORS FOR A SURGICAL CUTTING AND STAPLING INSTRUMENT, filed Feb. 15, 2008, now U.S. Pat. No. 7,980,443;U.S. patent application Ser. No. 12/235,782, entitled MOTOR-DRIVEN SURGICAL CUTTING INSTRUMENT, now U.S. Pat. No. 8,210,411;U.S. patent application Ser. No. 12/235,972, entitled MOTORIZED SURGICAL INSTRUMENT, now U.S. Pat. No. 9,050,083.U.S. patent application Ser. No. 12/249,117, entitled POWERED SURGICAL CUTTING AND STAPLING APPARATUS WITH MANUALLY RETRACTABLE FIRING SYSTEM, now U.S. Pat. No. 8,608,045;U.S. patent application Ser. No. 12/647,100, entitled MOTOR-DRIVEN SURGICAL CUTTING INSTRUMENT WITH ELECTRIC ACTUATOR DIRECTIONAL CONTROL ASSEMBLY, filed Dec. 24, 2009, now U.S. Pat. No. 8,220,688;U.S. patent application Ser. No. 12/893,461, entitled STAPLE CARTRIDGE, filed Sep. 29, 2012, now U.S. Pat. No. 8,733,613;U.S. patent application Ser. No. 13/036,647, entitled SURGICAL STAPLING INSTRUMENT, filed Feb. 28, 2011, now U.S. Pat. No. 8,561,870;U.S. patent application Ser. No. 13/118,241, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, now U.S. Pat. No. 9,072,535;U.S. patent application Ser. No. 13/524,049, entitled ARTICULATABLE SURGICAL INSTRUMENT COMPRISING A FIRING DRIVE, filed on Jun. 15, 2012, now U.S. Pat. No. 9,101,358;U.S. patent application Ser. No. 13/800,025, entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on Mar. 13, 2013, now U.S. Pat. No. 9,345,481;U.S. patent application Ser. No. 13/800,067, entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on Mar. 13, 2013, now U.S. Patent Application Publication No. 2014/0263552;U.S. Patent Application Publication No. 2007/0175955, entitled SURGICAL CUTTING AND FASTENING INSTRUMENT WITH CLOSURE TRIGGER LOCKING MECHANISM, filed Jan. 31, 2006; andU.S. Patent Application Publication No. 2010/0264194, entitled SURGICAL STAPLING INSTRUMENT WITH AN ARTICULATABLE END EFFECTOR, filed Apr. 22, 2010, now U.S. Pat. No. 8,308,040, are hereby incorporated by reference herein. Examples Example 1—A surgical instrument, comprising a shaft, and an end effector extending from the shaft. The end effector comprises a first jaw comprising a jaw frame including a threaded jaw aperture and a distal jaw end, and a second jaw rotatable relative to the first jaw. The surgical instrument further comprises a firing drive, comprising an electric motor comprising a rotatable output. The firing drive further comprises a rotatable drive shaft rotatably and translatably engaged with the rotatable output. The rotatable drive shaft comprises a proximal threaded portion and a distal threaded portion, wherein the proximal threaded portion is threadably engaged with the threaded jaw aperture. The rotatable drive shaft translates distally toward the distal end when the rotatable drive shaft is rotated in a first direction and translates proximally away from the distal end when the rotatable drive shaft is rotated in an opposite direction. The firing drive further comprises a tissue cutting knife threadably engaged with the distal threaded portion. The tissue cutting knife comprises a knife edge, a first cam configured to engage the first jaw during a firing stroke, and a second cam configured to engage the second jaw during the firing stroke. The tissue cutting knife further comprises a threaded drive aperture threadably engaged with the distal threaded portion of the rotatable drive shaft. The tissue cutting knife translates distally relative to the rotatable drive shaft when the rotatable drive shaft is rotated in the first direction and translates proximally relative to the rotatable drive shaft when the rotatable drive shaft is rotated in an opposite direction. Example 2—The surgical instrument of Example 1, wherein the proximal threaded portion comprises a first thread pitch, and wherein the distal threaded portion comprises a second thread pitch which is different than the first thread pitch. Example 3—The surgical instrument of Examples 1 or 2, wherein, for a given speed of the electric motor, the rotatable drive shaft translates relative to the first jaw at a first advancement rate and the tissue cutting knife translates relative to the rotatable drive shaft at a second advancement rate which is different than the first advancement rate. Example 4—The surgical instrument of Example 3, wherein the second advancement rate is faster than the first advancement rate. Example 5—The surgical instrument of Example 3, wherein the first advancement rate is faster than the second advancement rate. Example 6—The surgical instrument of Examples 1, or 2, wherein, for a given speed of the electric motor, the rotatable drive shaft translates relative to the first jaw at a first advancement rate and the tissue cutting knife translates relative to the first jaw at a second advancement rate which is different than the first advancement rate. Example 7—The surgical instrument of Example 6, wherein the second advancement rate is faster than the first advancement rate. Example 8—The surgical instrument of Examples 6 or 7, wherein the second advancement rate is twice as fast as the first advancement rate. Example 9—The surgical instrument of Example 1, wherein, for a given speed of the electric motor, the rotatable drive shaft translates relative to the first jaw at a first advancement rate and the tissue cutting knife translates relative to the rotatable drive shaft at a second advancement rate which is the same as the first advancement rate. Example 10—The surgical instrument of Examples 1, 2, 3, 4, 5, 6, 7, 8, or 9, further comprising a staple cartridge positioned in the first jaw. Example 11—The surgical instrument of Example 10, wherein the staple cartridge comprises an electrode. Example 12—The surgical instrument of Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11, wherein the second jaw comprises an electrode. Example 13—The surgical instrument of Examples 1, 2, 3, 4, 5, 6, 7, 8, or 9, further comprising a staple cartridge positioned in the second jaw. Example 14—The surgical instrument of Example 13, wherein the staple cartridge comprises an electrode. Example 15—The surgical instrument of Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, 13, or 14, wherein the first jaw comprises an electrode. Example 16—The surgical instrument of Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15, further comprising a handle, wherein the shaft extends from the handle. Example 17—The surgical instrument of Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16, further comprising a housing configured to be attached to a robotic surgical system, wherein the shaft extends from the housing. Example 18—The surgical instrument of Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, or 17, wherein the proximal threaded portion comprises right-hand threads and the distal threaded portion comprises left-hand threads. Example 19—A stapling instrument, comprising a shaft, and an end effector extending from the shaft. The end effector comprises a first jaw comprising a jaw frame including a threaded jaw interface and a distal jaw end, a second jaw rotatable relative to the first jaw, and a replaceable staple cartridge comprising staples removably stored therein. The stapling instrument further comprises a firing drive, comprising an electric motor comprising a rotatable output. The firing drive further comprises a rotatable drive shaft rotatably and translatably engaged with the rotatable output. The rotatable drive shaft comprises a proximal threaded portion and a distal threaded portion, wherein the proximal threaded portion is threadably engaged with the threaded jaw interface. The rotatable drive shaft translates distally toward the distal end when the rotatable drive shaft is rotated in a first direction and translates proximally away from the distal end when the rotatable drive shaft is rotated in an opposite direction. The firing drive further comprises a firing member threadably engaged with the distal threaded portion. The firing member comprises a first cam configured to engage the first jaw during a firing stroke, a second cam configured to engage the second jaw during the firing stroke, and a threaded drive interface threadably engaged with the distal threaded portion of the rotatable drive shaft. The firing member translates distally relative to the rotatable drive shaft when the rotatable drive shaft is rotated in the first direction and translates proximally relative to the rotatable drive shaft when the rotatable drive shaft is rotated in an opposite direction. Example 20—The stapling instrument of Example 19, wherein the staple cartridge comprises an electrode. Although various devices have been described herein in connection with certain embodiments, modifications and variations to those embodiments may be implemented. Particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, the particular features, structures, or characteristics illustrated or described in connection with one embodiment may be combined in whole or in part, with the features, structures or characteristics of one or more other embodiments without limitation. Also, where materials are disclosed for certain components, other materials may be used. Furthermore, according to various embodiments, a single component may be replaced by multiple components, and multiple components may be replaced by a single component, to perform a given function or functions. The foregoing description and following claims are intended to cover all such modification and variations. The devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. In either case, however, a device can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps including, but not limited to, the disassembly of the device, followed by cleaning or replacement of particular pieces of the device, and subsequent reassembly of the device. In particular, a reconditioning facility and/or surgical team can disassemble a device and, after cleaning and/or replacing particular parts of the device, the device can be reassembled for subsequent use. Those skilled in the art will appreciate that reconditioning of a device can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application. The devices disclosed herein may be processed before surgery. First, a new or used instrument may be obtained and, when necessary, cleaned. The instrument may then be sterilized. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and instrument may then be placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, and/or high-energy electrons. The radiation may kill bacteria on the instrument and in the container. The sterilized instrument may then be stored in the sterile container. The sealed container may keep the instrument sterile until it is opened in a medical facility. A device may also be sterilized using any other technique known in the art, including but not limited to beta radiation, gamma radiation, ethylene oxide, plasma peroxide, and/or steam. While this invention has been described as having exemplary designs, the present invention may be further modified within the spirit and scope of the disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. The foregoing detailed description has set forth various forms of the devices and/or processes via the use of block diagrams, flowcharts, and/or examples. Insofar as such block diagrams, flowcharts, and/or examples contain one or more functions and/or operations, it will be understood by those within the art that each function and/or operation within such block diagrams, flowcharts, and/or examples can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. Those skilled in the art will recognize that some aspects of the forms disclosed herein, in whole or in part, can be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the subject matter described herein are capable of being distributed as one or more program products in a variety of forms, and that an illustrative form of the subject matter described herein applies regardless of the particular type of signal bearing medium used to actually carry out the distribution. Instructions used to program logic to perform various disclosed aspects can be stored within a memory in the system, such as dynamic random access memory (DRAM), cache, flash memory, or other storage. Furthermore, the instructions can be distributed via a network or by way of other computer readable media. Thus a machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer), but is not limited to, floppy diskettes, optical disks, compact disc, read-only memory (CD-ROMs), and magneto-optical disks, read-only memory (ROMs), random access memory (RAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic or optical cards, flash memory, or a tangible, machine-readable storage used in the transmission of information over the Internet via electrical, optical, acoustical or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.). Accordingly, the non-transitory computer-readable medium includes any type of tangible machine-readable medium suitable for storing or transmitting electronic instructions or information in a form readable by a machine (e.g., a computer). As used in any aspect herein, the term “control circuit” may refer to, for example, hardwired circuitry, programmable circuitry (e.g., a computer processor including one or more individual instruction processing cores, processing unit, processor, microcontroller, microcontroller unit, controller, digital signal processor (DSP), programmable logic device (PLD), programmable logic array (PLA), or field programmable gate array (FPGA)), state machine circuitry, firmware that stores instructions executed by programmable circuitry, and any combination thereof. The control circuit may, collectively or individually, be embodied as circuitry that forms part of a larger system, for example, an integrated circuit (IC), an application-specific integrated circuit (ASIC), a system on-chip (SoC), desktop computers, laptop computers, tablet computers, servers, smart phones, etc. Accordingly, as used herein “control circuit” includes, but is not limited to, electrical circuitry having at least one discrete electrical circuit, electrical circuitry having at least one integrated circuit, electrical circuitry having at least one application specific integrated circuit, electrical circuitry forming a general purpose computing device configured by a computer program (e.g., a general purpose computer configured by a computer program which at least partially carries out processes and/or devices described herein, or a microprocessor configured by a computer program which at least partially carries out processes and/or devices described herein), electrical circuitry forming a memory device (e.g., forms of random access memory), and/or electrical circuitry forming a communications device (e.g., a modem, communications switch, or optical-electrical equipment). Those having skill in the art will recognize that the subject matter described herein may be implemented in an analog or digital fashion or some combination thereof. As used in one or more aspects of the present disclosure, a microcontroller may generally comprise a memory and a microprocessor (“processor”) operationally coupled to the memory. The processor may control a motor driver circuit generally utilized to control the position and velocity of a motor, for example. In certain instances, the processor can signal the motor driver to stop and/or disable the motor, for example. In certain instances, the microcontroller may be an LM 4F230H5QR, available from Texas Instruments, for example. In at least one example, the Texas Instruments LM4F230H5QR is an ARM Cortex-M4F Processor Core comprising on-chip memory of 256 KB single-cycle flash memory, or other non-volatile memory, up to 40 MHz, a prefetch buffer to improve performance above 40 MHz, a 32 KB single-cycle serial random access memory (SRAM), internal read-only memory (ROM) loaded with StellarisWare® software, 2 KB electrically erasable programmable read-only memory (EEPROM), one or more pulse width modulation (PWM) modules, one or more quadrature encoder inputs (QEI) analog, one or more 12-bit Analog-to-Digital Converters (ADC) with 12 analog input channels, among other features that are readily available for the product datasheet. It should be understood that the term processor as used herein includes any suitable microprocessor, or other basic computing device that incorporates the functions of a computer's central processing unit (CPU) on an integrated circuit or at most a few integrated circuits. The processor is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and provides results as output. It is an example of sequential digital logic, as it has internal memory. Processors operate on numbers and symbols represented in the binary numeral system. In at least one instance, the processor may be any single core or multicore processor such as those known under the trade name ARM Cortex by Texas Instruments. Nevertheless, other suitable substitutes for microcontrollers and safety processor may be employed, without limitation. As used in any aspect herein, the term “logic” may refer to an app, software, firmware and/or circuitry configured to perform any of the aforementioned operations. Software may be embodied as a software package, code, instructions, instruction sets and/or data recorded on non-transitory computer readable storage medium. Firmware may be embodied as code, instructions or instruction sets and/or data that are hard-coded (e.g., nonvolatile) in memory devices. As used in any aspect herein, the terms “component,” “system,” “module” and the like can refer to a computer-related entity, either hardware, a combination of hardware and software, software, or software in execution. As used in any aspect herein, an “algorithm” refers to a self-consistent sequence of steps leading to a desired result, where a “step” refers to a manipulation of physical quantities and/or logic states which may, though need not necessarily, take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It is common usage to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. These and similar terms may be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities and/or states. A network may include a packet switched network. The communication devices may be capable of communicating with each other using a selected packet switched network communications protocol. One example communications protocol may include an Ethernet communications protocol which may be capable permitting communication using a Transmission Control Protocol/Internet Protocol (TCP/IP). The Ethernet protocol may comply or be compatible with the Ethernet standard published by the Institute of Electrical and Electronics Engineers (IEEE) titled “IEEE 802.3 Standard”, published in December, 2008 and/or later versions of this standard. Alternatively or additionally, the communication devices may be capable of communicating with each other using an X.25 communications protocol. The X.25 communications protocol may comply or be compatible with a standard promulgated by the International Telecommunication Union-Telecommunication Standardization Sector (ITU-T). Alternatively or additionally, the communication devices may be capable of communicating with each other using a frame relay communications protocol. The frame relay communications protocol may comply or be compatible with a standard promulgated by Consultative Committee for International Telegraph and Telephone (CCITT) and/or the American National Standards Institute (ANSI). Alternatively or additionally, the transceivers may be capable of communicating with each other using an Asynchronous Transfer Mode (ATM) communications protocol. The ATM communications protocol may comply or be compatible with an ATM standard published by the ATM Forum titled “ATM-MPLS Network Interworking 2.0” published August 2001, and/or later versions of this standard. Of course, different and/or after-developed connection-oriented network communication protocols are equally contemplated herein. As used in any aspect herein, a wireless transmission such as, for example, a wireless communication or a wireless transfer of a data signal can be achieved, by a device including one or more transceivers. The transceivers may include, but are not limited to cellular modems, wireless mesh network transceivers, Wi-Fi® transceivers, low power wide area (LPWA) transceivers, and/or near field communications transceivers (NFC). The device may include or may be configured to communicate with a mobile telephone, a sensor system (e.g., environmental, position, motion, etc.) and/or a sensor network (wired and/or wireless), a computing system (e.g., a server, a workstation computer, a desktop computer, a laptop computer, a tablet computer (e.g., iPad®, GalaxyTab® and the like), an ultraportable computer, an ultramobile computer, a netbook computer and/or a subnotebook computer; etc. In at least one aspect of the present disclosure, one of the devices may be a coordinator node. The transceivers may be configured to receive serial transmit data via respective universal asynchronous receiver-transmitters (UARTs) from a processor to modulate the serial transmit data onto an RF carrier to produce a transmit RF signal and to transmit the transmit RF signal via respective antennas. The transceiver(s) can be further configured to receive a receive RF signal via respective antennas that includes an RF carrier modulated with serial receive data, to demodulate the receive RF signal to extract the serial receive data and to provide the serial receive data to respective UARTs for provision to the processor. Each RF signal has an associated carrier frequency and an associated channel bandwidth. The channel bandwidth is associated with the carrier frequency, the transmit data and/or the receive data. Each RF carrier frequency and channel bandwidth is related to the operating frequency range(s) of the transceiver(s). Each channel bandwidth is further related to the wireless communication standard and/or protocol with which the transceiver(s) may comply. In other words, each transceiver may correspond to an implementation of a selected wireless communication standard and/or protocol, e.g., IEEE 802.11 a/b/g/n for Wi-Fi® and/or IEEE 802.15.4 for wireless mesh networks using Zigbee routing. One or more drive systems or drive assemblies, as described herein, employ one or more electric motors. In various forms, the electric motors may be a DC brushed driving motor, for example. In other arrangements, the motor may include a brushless motor, a cordless motor, a synchronous motor, a stepper motor, or any other suitable electric motor. The electric motors may be powered by a power source that in one form may comprise a removable power pack. Batteries may each comprise, for example, a Lithium Ion (“LI”) or other suitable battery. The electric motors can include rotatable shafts that operably interface with gear reducer assemblies, for example. In certain instances, a voltage polarity provided by the power source can operate an electric motor in a clockwise direction wherein the voltage polarity applied to the electric motor by the battery can be reversed in order to operate the electric motor in a counter-clockwise direction. In various aspects, a microcontroller controls the electric motor through a motor driver via a pulse width modulated control signal. The motor driver can be configured to adjust the speed of the electric motor either in clockwise or counter-clockwise direction. The motor driver is also configured to switch between a plurality of operational modes which include an electronic motor braking mode, a constant speed mode, an electronic clutching mode, and a controlled current activation mode. In electronic braking mode, two terminal of the drive motor200are shorted and the generated back EMF counteracts the rotation of the electric motor allowing for faster stopping and greater positional precision. Unless specifically stated otherwise as apparent from the foregoing disclosure, it is appreciated that, throughout the foregoing disclosure, discussions using terms such as “processing,” “computing,” “calculating,” “determining,” “displaying,” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices. One or more components may be referred to herein as “configured to,” “configurable to,” “operable/operative to,” “adapted/adaptable,” “able to,” “conformable/conformed to,” etc. Those skilled in the art will recognize that “configured to” can generally encompass active-state components and/or inactive-state components and/or standby-state components, unless context requires otherwise. Those skilled in the art will recognize that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to claims containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that typically a disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms unless context dictates otherwise. For example, the phrase “A or B” will be typically understood to include the possibilities of “A” or “B” or “A and B.” With respect to the appended claims, those skilled in the art will appreciate that recited operations therein may generally be performed in any order. Also, although various operational flow diagrams are presented in a sequence(s), it should be understood that the various operations may be performed in other orders than those which are illustrated, or may be performed concurrently. Examples of such alternate orderings may include overlapping, interleaved, interrupted, reordered, incremental, preparatory, supplemental, simultaneous, reverse, or other variant orderings, unless context dictates otherwise. Furthermore, terms like “responsive to,” “related to,” or other past-tense adjectives are generally not intended to exclude such variants, unless context dictates otherwise. It is worthy to note that any reference to “one aspect,” “an aspect,” “an exemplification,” “one exemplification,” and the like means that a particular feature, structure, or characteristic described in connection with the aspect is included in at least one aspect. Thus, appearances of the phrases “in one aspect,” “in an aspect,” “in an exemplification,” and “in one exemplification” in various places throughout the specification are not necessarily all referring to the same aspect. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more aspects. In this specification, unless otherwise indicated, terms “about” or “approximately” as used in the present disclosure, unless otherwise specified, means an acceptable error for a particular value as determined by one of ordinary skill in the art, which depends in part on how the value is measured or determined. In certain embodiments, the term “about” or “approximately” means within 1, 2, 3, or 4 standard deviations. In certain embodiments, the term “about” or “approximately” means within 50%, 20%, 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, or 0.05% of a given value or range. In this specification, unless otherwise indicated, all numerical parameters are to be understood as being prefaced and modified in all instances by the term “about,” in which the numerical parameters possess the inherent variability characteristic of the underlying measurement techniques used to determine the numerical value of the parameter. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter described herein should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Any numerical range recited herein includes all sub-ranges subsumed within the recited range. For example, a range of “1 to 10” includes all sub-ranges between (and including) the recited minimum value of 1 and the recited maximum value of 10, that is, having a minimum value equal to or greater than 1 and a maximum value equal to or less than 10. Also, all ranges recited herein are inclusive of the end points of the recited ranges. For example, a range of “1 to 10” includes the end points 1 and 10. Any maximum numerical limitation recited in this specification is intended to include all lower numerical limitations subsumed therein, and any minimum numerical limitation recited in this specification is intended to include all higher numerical limitations subsumed therein. Accordingly, Applicant reserves the right to amend this specification, including the claims, to expressly recite any sub-range subsumed within the ranges expressly recited. All such ranges are inherently described in this specification. Any patent application, patent, non-patent publication, or other disclosure material referred to in this specification and/or listed in any Application Data Sheet is incorporated by reference herein, to the extent that the incorporated materials is not inconsistent herewith. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material. In summary, numerous benefits have been described which result from employing the concepts described herein. The foregoing description of the one or more forms has been presented for purposes of illustration and description. It is not intended to be exhaustive or limiting to the precise form disclosed. Modifications or variations are possible in light of the above teachings. The one or more forms were chosen and described in order to illustrate principles and practical application to thereby enable one of ordinary skill in the art to utilize the various forms and with various modifications as are suited to the particular use contemplated. It is intended that the claims submitted herewith define the overall scope.

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DETAILED DESCRIPTION The disclosed stapling devices will now be described in detail with reference to the drawings in which like reference numerals designate identical or corresponding elements in each of the several views. However, it is to be understood that the disclosed aspects of the disclosure are merely exemplary of the disclosure and may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the disclosure in virtually any appropriately detailed structure. In addition, directional terms such as front, rear, upper, lower, top, bottom, distal, proximal, and similar terms are used to assist in understanding the description and are not intended to limit the disclosure. In this description, the term “proximal” is used generally to refer to that portion of the device that is closer to a clinician, while the term “distal” is used generally to refer to that portion of the device that is farther from the clinician. In addition, the term “endoscopic” is used generally to refer to endoscopic, laparoscopic, arthroscopic, and/or any other procedure conducted through a small diameter incision or cannula. Further, the term “clinician” is used generally to refer to medical personnel including doctors, nurses, and support personnel. The disclosed surgical stapling device includes a reload assembly having a cartridge assembly and a shipping cap. As will be described in detail below, the shipping cap is configured to remain secured to the replaceable cartridge assembly until the reload assembly is properly installed on the surgical stapling device. FIG.1illustrates the disclosed surgical stapling device shown generally as stapling device10. The stapling device10defines a longitudinal axis “X” and includes a body12defining a stationary handle14, a pivotable trigger16that is movable relative to the stationary handle14, an elongated central body portion18extending from the body12, clamp slide members30, and an end effector20that is disposed on a distal end of the elongated central body portion18. The end effector20of the stapling device10includes an anvil assembly60and a replaceable cartridge assembly100. A shipping cap200is releasably attached to the replaceable cartridge assembly100to maintain the replaceable cartridge assembly100in operable condition during storage and shipping. A thumb button12ais slidably positioned on each side of the body12of the stapling device10. The thumb buttons12a(only one shown) are movable to manually advance an alignment pin144(FIG.6) of an alignment pin assembly140(FIG.3) of the replaceable cartridge assembly100. The stapling device10will be described to the extent necessary to fully disclose the aspects of the disclosure. For a detailed description of the internal structure and function of an exemplary surgical stapling device, please refer to commonly owned U.S. Pat. No. 6,817,508 (“the '508 patent”), and commonly owned U.S. Pat App. Pub. No. 2018/0153544 (“the '544 publication). FIG.2illustrates a distal portion of a frame50of the end effector20of the stapling device10(FIG.1). The distal portion of the frame50includes a base portion52and an L-shaped jaw portion54extending from the base portion52. The L-shaped jaw portion54includes a longitudinal portion54aand a transverse portion54b. The anvil assembly60is supported on the transverse portion54bof the jaw portion54of the frame assembly50and the replaceable cartridge assembly100is releasably supported within a head portion32defined by the clamp slide members30which are movably supported within the base portion52of the frame assembly50. The base portion52and the transverse portion54bof the jaw portion54of the frame assembly50of the end effector20are curved along an axis transverse to the longitudinal axis “X” of the stapling device10. For example, the end effector20may be C-shaped or include a first radius of curvature and a second radius of curvature. The first and second radii of curvature may be increased or decreased to suit a particular procedure and/or to facilitate access to a particular body cavity or location within a body cavity. The end effector20may also be formed by a plurality of substantially linear sections that are connected to each other to define a curved-like configuration. Alternatively, the base portion52and the transverse portion54bof the jaw portion54of the frame assembly50of the end effector20can have linear configurations. Each of the anvil assembly60and the replaceable cartridge assembly100include a configuration corresponding to the configuration of the frame assembly50of the end effector20. With continued reference toFIG.2, the head portion32defined by the clamp slide members30of stapling device10support the replaceable cartridge assembly100and is slidably supported within the base portion52of the frame assembly50of the end effector20. As disclosed in the '544 publication, the clamp slide members30advance in response to actuation of the trigger16(FIG.1) of the stapling device10(FIG.1) to cause advancement of the replaceable cartridge assembly100relative to the anvil assembly60. The head portion32of the clamp slide members30define a channel31that is configured to releasably support the replaceable cartridge assembly100. For a detailed description of the structure and operation of an exemplary end effector, please refer to the '544 publication. An alignment pin pusher or deployment member40is slidably supported within the elongated central body portion18of the stapling device10. The deployment member40has a distal end including an abutment member44that is positioned to engage with the alignment pin144of the alignment pin assembly140of the replaceable cartridge assembly100when the replaceable cartridge assembly100is supported on the end effector20. The deployment member40is operable to advance and retract the alignment pin144of the alignment pin assembly140. More specifically, the deployment member40is movable in response to movement of trigger16during an approximation stroke of the stapling device10to advance the alignment pin144of the alignment pin assembly140from a position within the replaceable cartridge assembly100into engagement with the anvil assembly60. Alternatively, the deployment member40can be manually advanced using the thumb buttons12ainto engagement with the anvil assembly60prior to actuation of the trigger16. The deployment member40will only be described to the extent necessary to fully disclose the aspects of the disclosure. For a detailed description of an exemplary deployment member, please refer to the '508 patent. The deployment member40of the stapling device10includes a vertical portion42(FIG.10) that supports the abutment member44(FIG.2). The abutment member44is configured to engage a base member142of the alignment pin assembly140of the replaceable cartridge assembly100such that when the deployment member40is advanced, the alignment pin144is advanced from within cartridge100into an opening (not shown) of the anvil assembly60. FIG.3illustrates the replaceable cartridge assembly100and the shipping cap200separated from the replaceable cartridge assembly100. The replaceable cartridge assembly100and the shipping cap200together form a reload assembly300. The replaceable cartridge assembly100of the stapling device10includes a housing110having a base portion112and an alignment pin retaining portion114connected to the base portion112. The base portion112supports a staple cartridge116. A pusher assembly130is operably supported within the base portion112, and the alignment pin assembly140is operably supported within the alignment pin retaining portion114. The shipping cap200includes a body portion210, and a staple retaining portion220extending perpendicular from the body portion210. The body portion210of the shipping cap200is configured to releasably engage the alignment pin retaining portion114of the housing110of the replaceable cartridge assembly100. More particularly, the body portion210includes first and second pairs of resilient arms212,214configured to be frictionally received about the alignment pin retaining portion114of the housing110of the replaceable cartridge assembly100, thereby creating a snap fit engagement with between the shipping cap200and the replaceable cartridge assembly100. Each arm of the first and second pairs of resilient arms212,214may be longitudinal offset from the other, as shown. A handle or grip portion216extends outwardly from the body portion210in a direction opposite to the resilient arms212,214and is configured for operable engagement by a user to facilitate separation of the shipping cap200from the replaceable loading unit100. A locking pin230extends from the body portion210opposite the handle portion216. As shown, the locking pin230is disposed between the first and second pairs of resilient arms212,214. The locking pin230includes a shaft portion232and a head portion234disposed on a free end of the shaft portion232. The head portion234of the locking pin230includes a diameter that is larger than a diameter of the shaft portion232. As will be described below, the locking pin230is configured to be selectively engaged by the alignment pin assembly140to selectively lock the shipping cap200to the replaceable cartridge assembly100to prevent premature separation of the shipping cap200from the replaceable cartridge assembly100. The staple retaining portion220of the shipping cap200includes a staple retaining surface222configured to be disposed adjacent a plurality of staple receiving pockets115(FIG.4) of the staple cartridge116. The staple retaining surface222ensures staples (not shown) supported within the staple cartridge116of the replaceable cartridge assembly100remain within the plurality of staple receiving pockets115of the staple cartridge116during shipping of the reload assembly300, and prior to the shipping cap200being separated from the replaceable cartridge assembly100. First and second pairs of clips224,226extend from the staple retaining portion220of the shipping cap200and form a snap fit engagement between the base portion112of the housing110of the replaceable cartridge assembly100and the staple retaining portion220, FIGS.4and5illustrate the replaceable cartridge assembly100with (FIG.5) and without (FIG.4) the shipping cap200attached. The replaceable cartridge assembly100will only be described to the extent necessary to fully disclose the aspects of the disclosure. For a detailed description of the structure and operation of an exemplary internal components of a cartridge assembly, e.g., a pusher assembly, please refer to the '544 publication. As noted above, the housing110of the replaceable cartridge assembly100includes the base portion112and the alignment, pin retaining portion114. The alignment pin retaining portion114defines a longitudinal channel115(FIG.5) for operably receiving the alignment pin assembly140(FIG.5). The alignment pin assembly140is maintained within the alignment pin retaining portion114by an end cap118. A proximal portion of the alignment pin retaining portion114defines a recess or relief117(FIG.10) that permits releasable engagement between the alignment pin assembly140and the abutment member44of the deployment member40(FIG.3). The alignment pin retaining portion114further defines an opening119(FIG.4) that is positioned to receive the locking pin230of the shipping cap200when the shipping cap200is attached to the replaceable cartridge assembly100. The alignment pin assembly140includes a base member142and the alignment pin144. The alignment pin144extends from the base member142distally towards the anvil assembly60(FIG.2) when the replaceable cartridge assembly100is secured to the clamp slide members30(FIG.2) of the end effector20. Although shown as being separate components, it is envisioned that the base member142and the alignment pin144may be integrally formed with each other. As described below, the alignment pin144of the alignment pin assembly140is moveable between a locked or retracted position (FIG.8) and an unlocked position (FIG.12) to permit separation of the shipping cap200from the replaceable cartridge assembly100. The alignment pin144is further movable from the unlocked position to an advanced position (not shown) in engagement with the anvil assembly60to provide alignment between the replaceable cartridge assembly100and the anvil assembly60during operation of the stapling device10(FIG.1). The alignment pin144is biased to the retracted position by a spring146. FIGS.6and7illustrate the alignment pin144of the alignment pin assembly140. The alignment pin144includes an elongate body150having a proximal portion150aconfigured for engagement with the base member142of the alignment pin assembly140and a tapered distal portion150bconfigured to facilitate receipt of the alignment pin144within an opening (not shown) formed in the anvil assembly60(FIG.2). The proximal portion150aof the alignment pin144may include one or more notches145, or be otherwise configured to facilitate secure engagement of the alignment pin144with the base member142(FIG.5). The proximal portion150aof the alignment pin144may be secured to the base member142by friction fit, adhesive, welding, or in any other suitable manner. The elongate body150of the alignment pin144defines a key hole slot151. The key hole slot151includes a first portion153and a second portion155in communication with the first portion153. The first portion153of the key hole slot151is sized and dimensioned to receive the head portion234of the locking pin230of the shipping cap200. The second portion155of the key hole slot151is sized and dimensioned to receive at least a portion of the shaft portion232of the locking pin230. As shown, the first portion153is circular and the second portion is rectangular, however, the first and second portions153,155may be of any shape. The key hole slot151is positioned on the elongate body150of the alignment pin144such that the first portion153of the key hole slot151aligns with the opening119(FIG.4) in the alignment pin retaining portion114of the housing112of the replaceable cartridge assembly100when the alignment pin144is in the locked position and the second portion155aligns with the opening119when the alignment pin144is in the unlocked position. FIGS.8and9illustrate the reload assembly300including the shipping cap200attached to the replaceable cartridge assembly100with the alignment pin144of the alignment pin assembly140in the locked or retracted position to prevent separation of the shipping cap200from the replaceable cartridge assembly100. When the shipping cap200is attached to the replaceable cartridge assembly100, the locking pin230is received through the opening119(FIG.4) in the alignment pin retaining portion114of the housing110of the replaceable cartridge assembly100and through the key hole slot151in the elongate body150of the alignment pin144. When the alignment pin144is in the locked or retracted position, the shaft portion232of the locking pin230of the shipping cap200is received within the second portion153of the key hole slot151. In this manner, the head portion234of the locking pin232engages the body portion150of the alignment pin144, thereby preventing the locking pin230from being withdrawn through the key hole slot151, thus locking the shipping cap200to the replaceable cartridge assembly. FIGS.10-12illustrate the reload assembly300including the shipping cap200attached to the replaceable cartridge assembly100with the alignment pin144of the alignment pin assembly140in the unlocked position to permit separation of the shipping cap200from the replaceable cartridge assembly100. When the alignment pin144is in the unlocked position, the shaft portion232of the locking pin230of the shipping cap200is received within the first portion153of the key hole slot151such that the head portion234of the locking pin230is aligned with the first portion153. In this manner, the locking pin230is free to be withdrawn through the first portion of the key hole slot151, thereby permitting separation of the shipping cap200from the replaceable cartridge assembly100. The alignment pin144of the alignment pin assembly140is moved against the bias of spring146to the unlocked position, as indicated by arrow “A” inFIGS.10-12, as the replaceable cartridge assembly100of the reload assembly300is loaded into to the end effector20(FIG.1) of the stapling device10. More particularly, loading the replaceable cartridge assembly100into the end effector20includes aligning the body portion112of the housing110of the replaceable cartridge assembly100with the channel31(FIG.2) between the head portion32of the clamp slide members30and moving the replaceable cartridge assembly100proximally within channel31, as indicated by arrow “B” inFIG.10. As the replaceable cartridge assembly100is moved proximally, the abutment portion44of the deployment member42engages the base member142of the alignment pin assembly140, causing the alignment pin144to move relative to the housing110of replaceable cartridge assembly100thereby unlocking the shipping assembly200from the replaceable cartridge assembly100. FIG.13illustrates the replaceable cartridge assembly100secured to the frame assembly50of the stapling device10(FIG.1) and the shipping cap200being separated from the replaceable cartridge assembly100after movement of the alignment pin144(FIG.12) to the unlocked position. Persons skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary aspects of the disclosed stapling device. It is envisioned that the elements and features illustrated or described in connection with one exemplary aspect of the disclosure may be combined with the elements and features of another without departing from the scope of the disclosure. As well, one skilled in the art will appreciate further features and advantages of the disclosure based on the above-described aspects of the disclosed ligation clip. Accordingly, the disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.

11857186

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The present disclosure provides disposable loading units which can be loaded into surgical instruments without removing the instruments from the body. That is, the loading units are loaded through a proximal opening in the surgical instrument and are engageable with an actuator of the surgical instrument to effect operation of the loading unit. In embodiments disclosed herein, the loading unit is loaded into a surgical fastener applier to apply fasteners to tissue clamped between the jaws of the loading unit. However, it is also contemplated that other loading units performing other functions can be loaded into the surgical instrument in situ. By enabling removal and reloading without removing the instrument from the body, the user does not need to relocate the instrument for each use, e.g., for each firing, which would otherwise be required if the instrument is removed from the surgical site, and reloaded outside the body of the patient. The present disclosure also provides instruments for receiving the loading units and a method for loading the loading units which are described in detail below. In some embodiments, instead of manual actuation of fastener firing and/or articulation, the loading unit actuation is effected by a battery and power train, which are loadable into a surgical fastener applier (stapler) to power various functions of the loading unit to reduce the forces exerted by the clinician otherwise required if manual force was utilized. The surgical staplers in these embodiments are designed to removably receive the power pack in a compartment or receptacle and the power pack interacts with the loading unit to effect firing of the fasteners, e.g. staples. In some instances, the power pack can be used to effect articulation of the jaw assembly of the loading unit to pivot the jaw assembly with respect to the longitudinal axis of the stapler. The surgical stapler could alternatively have a non-removable power train for effecting firing and/or articulation of the instrument. The power pack can also be utilized for powering endoscopic linear staplers, such as the stapler depicted inFIG.1A, other types of staplers as well as other surgical instruments. Examples of these instruments are discussed below. The loading units (magazines) are preferably disposable. The loading units can be designed/configured for use with endoscopic linear staplers as well as other types of staplers and other types of surgical instruments. Examples of these instruments are also discussed below. The loading units can be used with surgical instruments which are fully manually actuated or fully powered, or with surgical instruments wherein some functions are manually actuated and other functions are powered (e.g., powered by a motor). When the loading units are used with surgical staplers that dissect and join a given length of tissue, they enable multiple use, e.g., multiple firings, in a single procedure. That is, after the fasteners have been spent, the loading unit is proximally withdrawn from the stapler for loading of a fresh staple cartridge into the removed loading unit or alternatively a new loading unit with a fresh staple cartridge is provided. In either case, the loading unit with fresh staples is proximally loaded into the stapler, i.e., inserted through the back end of the handle assembly, without requiring the time consuming and sometimes difficult reinsertion/repositioning of the surgical stapler at the target site. This reloading of the surgical stapler can be repeated multiple times in the surgical procedure. When reloaded, the loading unit engages the handle assembly of the surgical stapler to interact with the actuators as described below. Thus, during a laparoscopic procedure for example, by removing and reloading the loading unit proximally while maintaining the instrument inside the patient's abdomen, the distal tip of the instrument remains within the field of view of the laparoscopic camera throughout the procedure. Referring now to the drawings and particular embodiments of the present disclosure, wherein like reference numerals identify similar structural features of the devices disclosed herein, there are illustrated several embodiments of the surgical instruments and removable power packs of the present disclosure. FIGS.1A-2Aillustrate one embodiment of an endoscopic linear stapler of the present disclosure which is inserted through a trocar (surgical port) and fires linear rows of surgical staples from a cartridge through tissue into contact with an anvil which forms the individual staples. (In some embodiments, the staplers can be inserted without a trocar). The stapler in this embodiment includes an open compartment in the handle housing that enables easy loading of the power pack within the stapler. The stapler could also include a compartment with a cover than is openable and closable as in the openable compartment disclosed inFIG.2B. In these versions with the cover, the staplers also provide a tight seal to protect the power pack from contaminants so that the power pack does not need to be sterilized for multiple uses. The power pack is engageable with a staple drive (staple firing) mechanism of the loading unit so that once the power pack and the loading unit are loaded in the stapler, actuation of the motor within the power pack effects firing of the staples through tissue. In some embodiments, the power pack is engageable with an articulation mechanism in the loading unit wherein actuation of the motor effects articulation of the jaw assembly of the loading unit. The powered articulation can be in addition to the powered staple firing or alternatively the stapler could have powered articulation and manual staple firing. A specific embodiment of such powered articulation included with powered firing is shown inFIGS.9A-10Dand discussed in detail below. Note in the embodiments discussed herein, the power pack could be loaded first, followed by insertion of the loading unit or alternatively the loading unit could be loaded first followed by insertion of the power pack. In the embodiments utilizing a power pack, the power pack with its motor driven mechanism has the advantages of reducing the force requirements of the user which can be high when multiple rows of staples are fired either simultaneously or sequentially from the stapler. The power pack in certain embodiments, such as inFIG.2B, can be held in a sealed compartment of the stapler, thereby avoiding the need for resterilization and its associated costs and risks, including the risk of damage to the electronic components by heat or chemicals. The term “surgical fasteners” as used herein encompasses staples having legs which are deformed by an anvil, two part fasteners wherein a fastener or staple component with legs is received and retained in a second component (retainer), and other types of fasteners which are advanced through tissue of a patient in performing surgical procedures. The term “proximal” as used herein denotes the region closer to the user and the term “distal” as used herein denotes the region further from the user. The terms “top” or “upper” and “bottom” or “lower” refer to the orientation of the instruments as shown in the orientation of the instrument inFIG.2A, with the compartment for receiving the power pack being on the top and the handle extending at the bottom. Turning initially toFIGS.1-2A, a first embodiment of the surgical stapler, power pack and loading unit are illustrated. In this embodiment, the power pack, which contains a battery, motor, drive mechanism and stapler engagement structure effects firing of the surgical fasteners (staples). The surgical stapler, also referred to herein as the surgical fastener applying instrument or surgical fastener applier, is designated generally by reference numeral10and includes a proximal portion14, a distal portion12and an elongated or endoscopic portion16(also referred to as an elongated tubular portion or shaft) extending between the proximal portion14and the distal portion12. A handle assembly15with a housing17(also referred to herein as a handle housing) is positioned at the proximal portion14and is configured to house and protect internal mechanisms of the stapler and receive the removable power pack when loaded (mounted) therein. The loading unit50(also referred to herein as the disposable loading unit or the magazine) includes an elongated member51(also referred to as an endoscopic portion or an elongated tubular member), a handle portion53of larger diameter, and a locking knob55at a proximal end. At the distal portion are opposing members, i.e., jaws,52a,52b, configured to clamp and constrain tissue during operation of the surgical stapler. At least one of the jaws is movable with respect to the other jaw from an open position to receive tissue between the jaws and a closed position to clamp tissue between the jaws. Thus, one of the jaws can be stationary and the other jaw movable with respect to the stationary jaw or alternatively both jaws can move, e.g., pivot, toward each other. In the embodiment ofFIG.1A, both jaw52b, which contains an anvil with staple forming pockets (staples) and jaw52awhich contains the cartridge supporting the row(s) of surgical fasteners, are movable toward and away from each other. In alternate embodiments, jaw52bwhich contains the anvil pockets is movable with respect to non-pivoting (stationary) jaw52awhich contains at least one row of surgical fasteners. In other alternate embodiments, the movable jaw52bcontains the surgical fasteners and the stationary jaw52acontains the anvil pockets. Jaws52a,52bare collectively referred to herein as jaws52. The fasteners are fired (advanced) from jaw52aby linear movement of a firing mechanism which engages staple drivers within the jaw52awhich move transverse to the longitudinal axis, i.e., transverse to the direction of movement of the firing mechanism, to sequentially advance (from proximal to distal) the staples in the linear rows of staples from the jaw52aand through tissue clamped by the jaws52to engage the anvil pockets on jaw52bfor formation of the staples. The fasteners can be contained in a separate cartridge60which is loaded into jaw52aprior to insertion of the loading unit50into the surgical instrument. The elongated tubular member16of stapler10extends distally from the housing17and is configured to fit through a surgical port (trocar) used for laparoscopic surgery. The elongated tubular member16can be of varying dimensions and in some embodiments is configured to fit through a 10 mm trocar, although other dimensions for fitting through other size trocars are also contemplated such as trocars ranging from 5 mm to 15 mm. It is advantageous to minimize the diameter of the endoscopic portion to minimize the size of the patient's incision. With the jaws52in the clamped position, the outer diameter of the elongated member16is maintained as the cross-sectional dimension of the closed jaws52preferably does not exceed the cross-sectional dimension (i.e., diameter) of the tubular member16. The loading unit50is inserted in a distal direction through a proximal opening23in the housing17, through a lumen in the housing17and through the lumen in elongated member16, with a portion of shaft51and the jaws52exiting the distal opening in the lumen of the elongated member16so jaws52extend distally of the elongated member16and are exposed. The loading unit50is removable by withdrawing the loading unit in a proximal direction (with the jaws52closed) so it is retracted through the lumen in elongated member16, the lumen in the housing17and out the proximal opening23. In the illustrated embodiment, the power pack30has a slot or channel34to accommodate the loading unit50. The loading unit50can in some embodiments include a joint54that provides for the articulation of the opposing jaw members52, i.e., pivoting of the jaw assembly (jaws52) to angular positions with respect to the longitudinal axis of elongated member51of the loading unit so (and thus with respect to the longitudinal axis of shaft16of the stapler10). Articulation can be achieved by linear motion of elongated members extending through the elongated member51which are slidable to angle the jaw assembly. The loading unit has a transverse rod58extending from a side of the handle portion53of the loading unit50to engage an internal wall of the handle assembly. Elongated slot56provides an opening for a first engagement member, e.g., flag, of the power pack30to engage the firing member which is internal of handle53and/or for a second engagement member, e.g., another flag, to engage the articulation member which is internal of handle53. The elongated member51has a laser cut portion59proximal of joint54. The jaw52aof proximally loaded loading unit50, as noted above and illustrated inFIG.2A, receives a cartridge60containing fasteners, e.g., staples. Thus, after firing, the cartridge60can be removed and a new cartridge60can be loaded into jaw52acontaining staples66, linear rows of slots62to receive the linear rows of staples66, stapler drivers to advance the staples transversely through the slots and a knife bar68(seeFIGS.4A and4B) advanceable in linear slot69to cut tissue between the rows of staples66. In a preferred embodiment, separate cartridges60are loaded into the proximal loading unit50after it is withdrawn proximally from the stapler so a single loading unit50can receive multiple cartridges60(seeFIGS.5A and5B). In an alternate embodiment, the proximally loaded loading unit can contain a non-removable cartridge so that a new proximal loading unit with a fresh array of fasteners replaces the loading unit with the fired staples. In either embodiment, the loading unit is proximally loaded into the stapler (in a distal direction) and withdrawn proximally from the stapler in situ. The instrument10can include a rotational member or knob22engageable with the loading unit50and configured to rotate, with respect to the handle assembly, the elongated member51and connected jaws52about the axis of the elongated member51, e.g., 360 degree rotation, to change the position of the jaws52. Articulation can be effected by manual manipulation of a lever adjacent the handle assembly15. A handle lever24, linked to an axially movable clamping bar within the loading unit, is pivotable from a first position to a second position closer to stationary handle26to effect movement of the jaw52band jaw52afrom an open (unclamped) position to a clamping position, also referred to as a closed position of the jaws52. Release of handle lever24returns the jaws52b,52ato their open position. A locking lever can be provided to retain the handle24in the closed position. Stationary handle28for grasping by the user is ergonomically designed for comfort of use. In summary, with a loading unit positioned within the stapler10, the surgical stapler10operates by manual pivoting of the lever24toward stationary handle26, wherein it can be locked by latch28, to clamp the tissue between jaws52, followed by powered firing of the staples from jaw52a, through the clamped tissue and into contact with the staple forming pockets of the anvil of jaw52b. Prior to firing, the jaws52can be rotated to a desired orientation by rotation of endoscopic portion51of loading unit50via knob22and/or articulated about joint54, via movement of the elongated articulation members, to a desired angled position with respect to the longitudinal axis of elongated portion51(and shaft16). Note articulation can performed by manual manipulation of a lever (not shown) which is operatively connected to an internal elongated member within the loading unit50which extends to joint54. A force applied to the internal elongated member pivots/articulates the jaws52about the joint54. Alternatively, powered articulation can be provided. The stapler can include a firing lock to maintain the jaws52a,52bin an actuation position. The firing lock may be engaged by squeezing the lever24of the handle assembly, which thus maintains the distal jaws52a,52bin the closed position. Upon completion of tissue joining and dissection, the firing lock may be released by fully squeezing the lever24to open jaws52a,52b, for example, through spring loading or the like. In some embodiments the loading unit can be inserted into the stapler and then rotated into a loading position. In these embodiments, the loading unit can include a knob with a locking position that provides an indication to a user that the surgical stapler is properly loaded. The housing17of the handle assembly15of the surgical stapler10is configured to receive the loadable/removable power pack30in receptacle25. In this embodiment, the power pack housing is not maintained in a sterile environment. In the alternate embodiment ofFIG.2B, the power pack35is fully contained within a compartment27bin the handle housing29and is therefore maintained in a sterile environment within the surgical instrument so it can be removed and reused in another procedure and/or instrument without the complexities, time, costs and risks of resterilization of the power pack. The sealed environment of the battery and power train within the housing also enables certain features/components to be used which might not otherwise be practical if sterilization of the internal power pack was required. Thus, by preventing contact between the power pack and the patient and/or bodily fluids and the external environment, resterilization is not required in this embodiment. The receptacle (compartment)27bincludes a base and side walls27chaving one or more guides27dthat cooperate with corresponding guiding structures37con the outer wall of the housing37aof power pack35for proper alignment of the power pack35in the handle assembly during insertion into the receptacle27b. In the embodiment ofFIG.2B, the guides37con power pack housing37aare in the form of a pair of ribs or projections37cextending transversely to a longitudinal axis of the power pack35for receipt within grooves formed between guides, e.g., ribs or projections,27dof the compartment27b, also extending transversely with respect to a longitudinal axis of the stapler. In the illustrated embodiment, the ribs37dare on opposing sides of the power pack35and are axially offset from each other, although in alternate embodiments they can be axially aligned. Additionally, a different number of ribs (axially or non-axially aligned) can be provided (with corresponding receiving structure in the compartment27b). It should be appreciated that alternatively, the grooves could be provided on the power pack35and the ribs provided on the walls in the compartment27bto provide the guiding structure for the power pack35. The guiding structure also helps to retain power pack35in position within the compartment27b. The power pack35has rear and front concave regions37b,37dto reduce its overall size. The power pack35can include a slot or channel (like slot34of power pack30) to receive/accommodate the loading unit50so it can be inserted through the proximal opening and endoscopic portion16′ of the stapler. The loading unit50is inserted through the proximal opening29aof the housing29. The handle assembly of the stapler includes handles24′ and26′, identical to handles24,26ofFIG.2A, and a rotatable knob22′ identical to knob22ofFIG.2A. A cover27afor opening and closing the receptacle27bcan be provided. The compartment cover27ais shown as being hingedly attached to the housing25, but may alternatively be fully removable or attached in some other manner such as a slidable connection or the like. The cover27ais shown pivotably mounted to a top portion of the housing29(in the orientation ofFIG.2D) for top loading of the power pack, although alternatively, side or bottom loading can be provided. The cover27apivots from a closed position to an open position ofFIG.2Bto enable loading of power pack35into the compartment27aof the housing29. In some embodiments, the cover27ais spring loaded to an open position so it remains open for loading of the power pack35. Once loaded, the cover27ais pivoted about its hinge to its closed position. A latch can be provided to latch the cover27ato the housing29in the closed position. When the cover27ais in an open position, the power pack35may be removed from the receptacle27bor inserted into the receptacle27b. In some embodiments, when the cover27ais in a closed position, the seal of the cover27ais in contact with the rim of the housing29such that the receptacle27b, and the power pack35if inserted into the receptacle27b, is sealed from the environment exterior to the surgical stapler. The top seal can be attached to the cover27aand in some embodiments can be in the form of an elastomer that is compressed by the housing, e.g., tightly fits slightly within the housing or is pressed on the rim of the housing29. In other embodiments, the elastomer seal can be on the housing29, i.e., extending around the perimeter of the rim of the compartment27b, and is compressed by the cover27ato seal between the cover27aand housing29. Other seals can also be provided within the surgical stapler to seal/protect the power pack35from contaminants, e.g., body fluids. After applications of fasteners and release (unclamping of the jaws from tissue), the cover27acan be opened and the power pack35removed and charged while the stapler and handle assembly are resterilized if the stapler is a reusable instrument or the stapler and handle assembly are disposed of if the stapler is a single use disposable instrument. The power pack35, due to its sealed configuration discussed above, can be reused without requiring sterilization by insertion into the receptacle of a resterilized handle assembly or a sterile handle assembly of an unused disposable handle assembly. The power packs30and35can be used with surgical instruments discarded after use (fully disposable instruments), partially disposable surgical instruments or with fully reusable/sterilizable instruments. The power packs are easily loadable in the surgical instrument, preferably the handle assembly or housing of the instrument, to easily and securely engage structure in the loading unit to effect movement of such structure. The power packs are also easily disengageable from the structure for removal from the housing. The power packs can be configured so they can be loadable and engageable in various types of surgical instruments. Turning now to the internal components of the power pack35of the present disclosure, and with reference toFIGS.8A-8G, one embodiment of the power pack35is shown which includes a motor assembly, battery and electronics contained within housing35a. (Power pack30contains the same components and arrangement as power pack35) More specifically, the power pack35includes a powering assembly including a motor32connected to a planetary gear box34configured to gear down the output of the motor32for proper drive speeds for firing staples from jaw52athrough the tissue into contact with the anvil of jaw52b. The planetary gear box34drives a lead screw36through one or more gears operatively connected to the motor shaft. More specifically, upon rotation of the motor shaft by motor32in a first direction, gear38is rotated in the same first direction, causing rotation of the gear31in a second opposite direction due to the intermeshed teeth of gears31and38. Lead screw36is operatively connected to gear31so that rotation of gear31causes rotation of lead screw36in the same direction. The power pack35includes a battery33which can be rechargeable outside the stapler when the power pack35is removed. The power pack35in some embodiments can include a power switch which is activated, i.e., turned on, by the clinician to start the motor and effect staple firing. In other embodiments, the motor can automatically turn on when the power pack is fully loaded or upon actuation of another control on the stapler housing17. In some embodiments, the motor can automatically turn off when the power pack is removed from the stapler housing. Note the power pack35has a different housing configuration than power pack30ofFIG.2A. However, the internal mechanisms are the same. Connected to the end of lead screw36(the end opposite the connection to the gear31) is a drive mechanism40. The drive mechanism40is configured to move in a linear motion (in an axial direction) along the lead screw36in response to rotation of the lead screw36. For example, the drive mechanism40may include internal threads that engage external threads of the lead screw36and may include slides engaged in a track that prevent the drive mechanism40from rotating and therefore cause the drive mechanism40to move linearly (axially) in response to rotation of the lead screw36. As depicted inFIGS.8A-8F, the power pack35has a compact configuration as the lead screw36extends alongside, slightly spaced from, the motor32and gear box34, i.e., both the motor32/gear box34and lead screw36extending longitudinally with the lead screw36parallel to the motor32. The drive mechanism40is connected to a proximal end of lead screw36and extends proximally of the proximal end of the motor32in the illustrated embodiment. The power pack35can have features/structure to constrain the motor32. In the embodiment ofFIG.8F, such feature is in the form of proximal rails70aand distal rails70bspaced apart axially within the housing17. Motor32is seated within proximal rails70aand gear box34is seated within rails70b, the rails70a,70bretaining the motor and preventing axial and rotational movement within the housing17. Bearing or bushings71aand71bcan also be provided to constrain the lead screw36at opposing ends, while allowing rotation thereof, thereby also constraining the motor. Other features can additionally or alternatively be provided to restrain the motor from axial movement while allowing rotation of the lead screw. The drive mechanism40includes a first output flag or yoke42, which is discussed in more detail below, configured to engage a staple firing mechanism, e.g., firing rod46, extending longitudinally within the disposable loading unit50. The staple firing rod46extends through the elongated portion51of the disposable loading unit50and is operatively engageable with a firing rod which is engageable with a series of staple drivers in jaw52ato advance the fasteners (staples)66from the fastener jaw52a. Alternatively, the firing rod46can extend through the elongated portion51and itself engage the stapler drivers as the camming surface of the firing rod46engages the staple drivers to sequentially fire the staples as the firing rod46is advanced. Thus, as the motor32generates rotational motion of the lead screw36through the planetary gear box34and the gears38,30, the drive mechanism40moves in linear motion along the lead screw36. Such linear motion effects linear movement of the firing rod46(due to the engagement of the boss44by the flag42) which advances the staple driving mechanism to advance (fire) the staples out from jaw52athrough tissue and into contact with the anvil in jaw52b. As noted above, the firing rod46can be a single element extending through the elongated portion51(terminating adjacent jaw52a) or alternatively can be attached to one or more components intermediate the firing rod46and jaw52a. A clamp bar can be positioned within and concentric with firing rod46. The clamp bar can be operatively connected to the pivotable handle24of stapler10via a linkage connecting one end of handle24to the distal end of clamp bar. In this manner, movement of pivotable handle24toward stationary handle28causes the operatively connected jaw clamping mechanism, e.g., the clamp rod, to be advanced distally to pivot jaw52btoward jaw52ato clamp tissue between the two jaws52. Note that for clamping, the clamp bar slides linearly within a lumen of firing rod46; for staple firing, firing rod46moves linearly over the clamp bar. The power pack30or35can also include in some embodiments one or more sensors to indicate the position of the firing rod46to indicate to the clinician the status of staple firing. For example, a proximal sensor and a distal sensor can be provided in the power pack housing to sense the position of yoke42of the drive mechanism40. Thus, the proximal sensor would sense the initial position of the yoke42(and thus the initial position of the firing rod46) and at the end of the firing stroke, the distal sensor would indicate the end (final) position of the yoke42(and thus the final positon of the firing rod46) which would indicate completed firing of the fasteners. The power pack30or35could also include an audible or visual indicator (viewable though the power pack housing and instrument handle housing) actuated by the sensor to indicate to the clinician the position of the flag42and thus the completion or status of the firing stroke to fire the fasteners. The power pack can also include sensors to detect the position of the articulation flag in the embodiments discussed below which have powered articulation. The sensor can include a potentiometer to determine the location during the firing stroke. It can also include an encoder to detect the position along the stroke. Alternatively, the stroke can also be identified by motor count. It is also contemplated that in alternate embodiments, the sensor(s) can be carried by the handle housing and/or the loading unit rather than (or in addition to) the power pack and utilized to detect the position of the flag42and/or firing rod46and/or detect the position of the articulation flag and/or articulation rod in the embodiments discussed below which have powered articulation. It is also contemplated that a sensor(s) can be provided to detect the position of the clamping rod for clamping the jaws. The sensor can be provided in (or supported by) the power pack or alternatively the sensor(s) can be carried by the loading unit and/or by the handle housing rather than (or in addition to) the power pack and utilized to detect the position of the jaws by detecting the position of the flag engaging the jaw clamping rod and/or detecting the position of the jaw clamping rod in the embodiments which have powered clamping. Note the sensor can be provided in some embodiments; in other embodiments, no sensor is provided. The output flag42of power pack18, as shown inFIG.8D, is configured to engage a bossed end44of the firing rod46of the loading unit50when the power pack18is fully inserted into the receptacle27bof the handle assembly17. As shown, the output flag (yoke)42has a receiving or mounting feature or member (also referred to as the engagement feature (member) or firing rod engagement feature (member) in the form of two arms43aand a slot43btherebetween, configured to frictionally (and releasably) engage the bossed end44, the feature aligning with the bossed end44during insertion. (The aforedescribed guiding structure on the power pack35and internal wall of the compartment27baid such alignment). Note the firing rod46is able to rotate when the first output flag42of the power pack35is engaged with the bossed end44. When the power pack35is secured to the firing rod46by the first output flag42, linear motion generated at the first output flag42by the motor actuated drive assembly is transferred to the firing rod46, which moves linearly to actuate the staple firing mechanism. That is, rotation of the gear30effects axial (linear) movement of the drive screw36which effects axial (linear) movement of the connected drive mechanism40to effect axial (linear) movement of the associated drive mechanism (rod) engaging member (i.e., flag42). It should be appreciated that flag42provides one example of the releasable attachment (engagement member) of the motor assembly to the firing rod46, it being understood that other mounting (engagement) members or features are also contemplated to engage the firing rod to advance it axially. In the alternate embodiment ofFIGS.7A-7C, the bossed end44′, when the loading unit50is sufficiently inserted into the stapler, engages edge49of output flag42′ (which is identical in structure and function to output flag42except for the angled edge49), which biases the bossed end44′ downwardly to compress spring19within the handle housing of the stapler. After boss44apasses edge49and is aligned with the recess/slot in the flag42, it is biased upwardly (in the orientation ofFIG.7C) toward the recess/slot by the spring19for engagement by the flag42′ as shown inFIG.7Cso the firing rod of the loading unit is engaged with the drive mechanism of the power pack. Note, in this embodiment, the bossed end44′ is a separate piece attached to rod46′ which effects firing in the same manner as rod46. In an alternate embodiment, the bossed end44′ and rod46′ can be one piece. In all other respects, the stapler10′ ofFIG.7Ais the same as stapler10ofFIG.1Aand corresponding parts (which have the same structures and functions) have been labeled with “prime” designations for convenience. In the embodiment ofFIGS.1-8F, the proximal loading unit50is used with a stapler10receiving a power pack35that actuates the firing rod46to fire the staples while other steps are performed manually. In summary, in this embodiment, in use, the jaws52a,52bare moved to the closed (clamped) position manually by a hand actuated lever or control, e.g., handle24. Also, in this embodiment, the jaws52are articulated with respect to the longitudinal axis of the endoscopic portion manually by a hand actuated lever or control. Thus, the clinician would manually clamp the jaws, manually rotate the endoscopic portion and attached jaws52, and manually articulate the jaws by manipulation of controls at the proximal end of the stapler10, e.g., at the handle15. It is also contemplated that the proximal loading unit can be used with a stapler wherein all or some of the steps/functions are manually actuated, i.e., clamping, articulation, and firing. An example of this is shown inFIG.15. Stapler220has a pawl224within the handle housing222. Loading unit230includes an engagement member232having a rack234engageable with the pawl224. Engagement member232is operatively connected to deployment/firing rod236at connection235. When handle226is moved toward handle228, due to the pawl/rack engagement at connection235, the engagement member232moves distally thereby causing the deployment (firing) rod236to move distally to fire the fasteners in the same manner as rod46described above. Stapler220can include a rotation knob223which functions like knob22. The loading unit230in all other respects is identical to the loading unit50and like loading unit50has a pair of jaws for clamping tissue with one jaw receiving the fasteners and an opposing jaw having an anvil. The loading unit can also provide for articulation of the jaws as in the aforedescribed embodiments. Note the stapler220ofFIG.15can be used to manually actuate loading units having other configurations such as the alternate loading units and alternate jaw assemblies disclosed herein. In some embodiments, the seal inside the tubular member, e.g., tubular member16, of the surgical stapler maintains positive pressure so that the loading unit may be removed and reloaded during use. The seal may be, for example, a silicone seal or the like. Additionally, since the seal maintains positive pressure, the tubular member of the surgical stapler may, advantageously, itself function in certain instances as a trocar for use with other surgical tools. In some embodiments, the handle lever24may have a mechanism operatively connected thereto that interacts with the loading unit50to prevent the lever24from being actuated, for example, by squeezing by a user, if the loading unit is not properly loaded into the surgical stapler. Additionally, in some embodiments, a user will advantageously be able to determine if the loading unit50is properly loaded into the surgical stapler via an alignment feature on the knob55of the loading unit50configured to indicate proper loading of the loading unit after sufficient insertion through the proximal entry opening23of the stapler such that the knob55enters a locking position. The locking mechanism may be configured to generate an indication to a user when the loading unit is in the locking position, such as an audible sound, tactile feedback, or the like, thereby indicating to a user that the surgical stapler is properly loaded. For instance, the loading unit50may be pushed against a spring force generated by a mechanism in the surgical stapler. (Note that the mechanism ofFIG.7Cdescribed herein could provide such audible or tactile feedback due to the spring action) Once in the locking position, the loading unit50can be retained until the locking mechanism is engaged to release the loading unit. FIG.1Ashows one embodiment, of an endoscopic linear stapler that can have proximal loaded loading unit of the present disclosure, andFIGS.6A and6Bshow the endoscopic linear stapler extending through a trocar T passing through tissue A. (FIG.6Bshows loading unit50prior to insertion in a distal direction through the handle and endoscopic portion16of the stapler10). However, the loading unit of the present disclosure is not limited to such endoscopic linear staplers. For example,FIGS.14A-14Cillustrate another endoscopic linear stapler, designated by reference numeral120, that can utilize the loading unit of the present disclosure. The stapler120can be manually actuated or can receive and be powered by the power pack30or35. Stapler120has a handle132manually pivotable towards stationary handle130for clamping of the jaws, an endoscopic portion or shaft124extending from the handle housing128, and a loading unit121with a jaw assembly containing jaws122a,122bat a distal portion of elongated member125. The endoscopic portion124is flexible which enables use in various endoscopic procedures. In some embodiments, the flexible endoscopic portion124can be stretched to make it more rigid to facilitate insertion of the loading unit121through the lumen in the endoscopic portion124. The stapler120also includes a rotation knob126for rotation of the elongated portion123of loading unit121to rotate the jaws122a,122b. Power pack35is shown fully loaded (inserted) within the handle housing128and the cover129closed to seal the power pack35from the external environment. As in the embodiment ofFIGS.8E-8F, the flag42extending from lead screw36engages a firing rod within the elongated member125of loading unit121to effect movement of the flexible firing rod to fire the staples when the motor of the power pack35is actuated. Power pack90having articulation described below can also be utilized with stapler120. Manual firing and/or manual articulation rather than powered are also contemplated. In use, the loading unit121is inserted in a distal direction through a proximal opening in the stapler and through a lumen in the handle housing128to extend through the lumen in endoscopic portion124. As noted above, the endoscopic portion can be stiffened prior to insertion of the loading unit121so it assumes a more linear position to facilitate insertion of the loading unit121. (The loading unit121could also be stiffened prior to insertion if it is provided with a flexible elongated member). The power pack35engages the loading unit121in a similar manner as engagement with loading unit50. As with loading unit50, after staple firing, the loading unit121can be removed by proximal withdrawal (retraction) through the endoscopic portion124and through the handle housing128and proximal opening for replacement with another loading unit with fresh staples, or replacement of the same loading unit with a fresh cartridge, for proximal loading into the stapler120. As noted above, the insertion (loading) and reloading with fresh staples can be achieved while the instrument remains in position, i.e., without moving the instrument from its location in the body and/or without withdrawing the instrument from the patient. The loading unit is also not limited to use with endoscopic linear staplers, nor is it limited to use with staplers.FIGS.13A and13Billustrate one example of a different stapler with a proximally loaded loading unit. As in the endoscopic linear staplers discussed herein, these staplers can also have a knife bar to cut tissue between the rows of staples applied to the tissue. By way of example, a proximal loaded loading unit can be used with a circular stapler that applies circular arrays of staples such as shown inFIGS.13A-13C. Surgical stapling instrument100can be manually powered or can receive and be powered by the power pack35or30of the present disclosure. Stapler100has a handle117manually pivotable towards stationary handle118for clamping of the jaws, an elongated tubular portion or shaft112extending from the handle housing116and a disposable loading101with a jaw assembly having an anvil (jaw)102and a cartridge (jaw)106containing circular arrays of fasteners (staples). The anvil102has a proximal clamping surface108and is movable by anvil rod104toward the cartridge106to clamp tissue between the anvil clamping surface108and distal clamping surface110of cartridge106by manual movement of handle117toward stationary handle118. The stapler100also includes a rotation knob114for rotation of the elongated portion (shaft)105of the loading unit101to rotate the jaws102,106. Power pack35is shown fully loaded (inserted) within the handle housing116and the cover is shown closed to seal the power pack35from the external environment. As in the embodiment ofFIGS.8A-8F, the flag42extending from lead screw36engages a firing rod within the loading unit101to effect movement of a firing rod extending through elongated portion105to fire the circular arrays of staples when the motor of the power pack35(or30) is actuated. Power pack90having articulation described below can also be utilized with stapler100. Manual firing and/or articulation is also contemplated. In use, the loading unit101is inserted through a proximal opening in the stapler100and through a lumen in the handle housing to extend through the lumen in elongated portion112. As with loading unit50, after staple firing, the loading unit101can be removed by proximal withdrawal (retraction) through the elongated portion112, the handle housing116and the proximal opening for replacement with another loading unit with fresh staples, or replacement of the same loading unit with a fresh cartridge and in some embodiments a fresh anvil, for proximal loading (in a distal direction) into the stapler100. As noted above, the insertion (loading) and reloading can be achieved while the instrument remains in position, i.e., without moving the instrument from its location in the body and/or without withdrawing the instrument from the patient. The anvil102can be tiltable as it is inserted through the housing116and elongated portion112to facilitate insertion. The cartridge106can also be tiltable for insertion. The anvil102and/or cartridge106can alternatively or in addition be collapsible and expandable to facilitate insertion through the elongated portion112. In the embodiments ofFIGS.8A-8F, a gear mechanism is driven by the motor to rotate the lead screw to advance the drive mechanism to effect firing of the staples. In the alternate embodiments ofFIGS.11A-12B, a belt drive mechanism is used to effect firing. The belt drive mechanism is contained in the power pack35or30(or90) in the same manner as the gear mechanism of the foregoing embodiments, and thus the power pack for the belt drive would include the housing35aof the configuration ofFIG.2Bor housing31of the configuration ofFIG.2Aand loaded in the stapler in the same manner as the power packs described above. The belt drives ofFIGS.11A-12Bare described below for use with the stapler ofFIG.1Abut can be used in the other surgical staplers and instruments disclosed herein which are designed to receive power pack30,35or power pack90for powered actuation. Turning first to the embodiment ofFIGS.11A-11B, the belt drive assembly (mechanism) includes a motor148connected to a planetary gear box150configured to gear down the output of the motor148for proper drive speeds for firing staples from jaw52athrough the tissue into contact with the anvil of jaw52b. The planetary gear box150drives a lead screw144via the drive belt operatively connected to the motor shaft. More specifically, upon rotation of the motor shaft by motor148, first rotatable disc152(also referred to as the first wheel or pulley) is rotated in a first direction, causing movement of belt156and rotation of second rotatable disc154(also referred to as the second wheel or pulley). Note the two discs152,154are spaced apart and not in contact. Lead screw144is operatively connected to disc154so that rotation of disc154causes rotation of lead screw144in the same direction. The power pack35(or30) includes a battery which can be rechargeable outside the stapler when the power pack35is removed. The motor148is actuated in the various ways described above with regard to power pack35ofFIG.8C. A tensioner can be provided such as tensioner158, illustratively in the form of a tension disc or wheel, to apply a force against the belt156. In the orientation ofFIG.11A, the tensioner158is positioned underneath the drive belt156and applies an upward tensioning force against the belt156in a direction toward discs152,154. Other types of mechanisms to apply a tensioning force to the belt are also contemplated for use in the embodiments ofFIGS.11A-12Bif such tensioning of the drive belt156is desired. Connected to the end of lead screw144(the end opposite of the connection to the disc154) is a drive mechanism142. The drive mechanism142, like drive mechanism40ofFIG.8A, is configured to move in a linear motion (in an axial direction) along the lead screw144in response to rotation of the lead screw144. For example, as in the drive mechanism40, drive mechanism142may include internal threads that engage external threads of the lead screw144and may include slides engaged in a track that prevent the drive mechanism142from rotating and therefore cause the drive mechanism142to move linearly in response to rotation of the lead screw144. As shown, the lead screw144extends alongside, slightly spaced from, the motor148and gear box150, i.e., both the motor148/gear box150and lead screw144extending longitudinally with the lead screw144parallel to the motor148. The drive mechanism142extends proximally of the proximal end of the motor148in the illustrated embodiment. The drive mechanism142, like drive mechanism140ofFIG.8E, includes a first output flag or yoke146with slot143configured to engage a staple firing rod46of the loading unit50extending longitudinally within the handle4. The flag146is the same as flag42ofFIG.8Eand engages the staple firing rod46in the same manner as flag42. Therefore, for brevity, further discussion of flag146and it engagement with firing rod46is not provided as the structure and function of flag42, and alternative firing rod engagement features, are fully applicable to flag146ofFIGS.11A-11B. In brief, as the motor148generates rotational motion of the lead screw144through the drive belt, the drive mechanism144moves in linear motion along the lead screw144to effect linear movement of the firing rod46which advances the staple driving mechanism to advance (fire) the staples out from jaw52athrough tissue and into contact with the anvil in jaw52b. In an alternate embodiment of a belt drive mechanism, the belt drive mechanism can have different sized discs (wheels). That is, one disc which is operatively connected to lead screw144is larger in diameter than other disc. Consequently, instead of providing a one to one ratio of the discs as in discs154and152ofFIG.11A, a greater ratio of disc to disc is provided which varies the output of motor168. That is, the rotational output of lead screw144is less than the rotational output of the motor shaft due to the differing degree of rotation due to the varying sizes. An example of such different sized discs is shown with the alternate belt drive mechanism ofFIGS.12A and12B. FIGS.12A-12Billustrate an alternate embodiment of a belt drive mechanism. The belt drive200differs from the belt drive ofFIG.11Ain that discs212,214have teeth to engage ribs or treads on belt216. As shown, the toothed discs212,214are spaced apart so their teeth/projections do not intermesh—the teeth of disc212engage belt216and the teeth of disc214engage belt216. Rotation of disc212moves drive belt216in the same direction due to its engagement with the teeth, which causes rotation of toothed disc214in the same direction due to engagement with its teeth to rotate lead screw204. In all other respects, mechanism200is identical to mechanism140. Belt drive mechanism (assembly)200has a motor208connected to a planetary gear box210configured to gear down the output of the motor208. The planetary gear box210drives a lead screw204through the belt drive operatively connected to the motor shaft. Upon rotation of the motor shaft by motor208, first disc (wheel or pulley)212is rotated in a first direction, causing movement of belt216and rotation of second disc (wheel or pulley)214. Lead screw204is operatively connected to disc214so that rotation of disc214causes rotation of lead screw204in the same direction. A tensioner218like tensioner158can be provided to apply tension to the belt216. The drive mechanism202, like the drive mechanism142ofFIG.11B, includes a first output flag or yoke206with slot203configured to engage a staple firing rod46of the proximal loading unit in the same manner as flag42. Rotation of the motor shaft generates rotational motion of the lead screw204through the drive belt, causing the drive mechanism202to move in linear motion along the lead screw204to effect linear movement of the firing rod46which advances the staple driving mechanism to advance (fire) the staples out from jaw52athrough tissue and into contact with the anvil in jaw52b. The second toothed disc214which is operatively connected to lead screw204is larger in diameter than first toothed disc2122. Consequently, instead of providing a one to one ratio of the discs as in discs154,152, a greater ratio of disc214to disc212is provided which varies the output of motor208. That is, the rotational output of lead screw204is less than the rotational output of the motor shaft due to the differing degree of rotation of discs214,212due to the varying sizes. It should be appreciated that in alternative embodiments, the toothed discs212214can be the same size as in the embodiment ofFIG.11A. It should be appreciated that the foregoing belt drive mechanisms can be used as an alternative to the gear mechanism in power pack30or35as well as an alternative to one or both of the gear mechanisms of power pack90discussed herein. In the foregoing embodiments, the power packs30and35were described for powering staple firing. In an alternate embodiment, the power pack can include a drive mechanism for effecting articulation. This motor powered articulation can be in addition to the motor powered staple firing, or alternatively, the power pack can be used solely for powered articulation. The embodiment ofFIGS.9A-10Dillustrate a power pack which powers both staple firing and articulation. If only for articulation, the power pack described herein (power pack90) would not include the gear mechanism engageable with the firing rod46for staple firing. The power pack90can be loaded in the staplers disclosed herein in the same manner as power pack35and30, however, the engagement features of the power pack90engage both the firing rod of the loading unit, e.g., loading unit50, as well as the articulation rod of the loading unit. In the illustrated embodiment, the power pack90is shaped like power pack35and can have guides e.g., projections90a,90b, either axially aligned or axially offset, similar to guides37cof power pack35for alignment with guiding structure in the compartment of the stapler More specifically, the power pack has a motor assembly and drive mechanism for firing staples which is identical to that of the power pack35ofFIG.2B. However, power pack90differs from power pack35(and power pack30) in that it additionally has a motor assembly and drive mechanism for articulating the jaws of the loading unit. The addition of the articulation assembly can be appreciated by a comparison of the cross-sectional view ofFIG.8F, which only effects firing of the fasteners (staplers), and the cross-sectional view ofFIG.9Dwhich effects firing of fasteners and articulation of the jaw assembly. The powered staple firing assembly like the firing assembly of power pack35ofFIG.8F, includes a motor83connected to a planetary gear box85configured to gear down the output of the motor in the same manner as motor32and gear box34of power pack35. The planetary gear box85drives a lead screw86through one or more gears operatively connected to the motor shaft. Upon rotation of the motor shaft by the motor83in a first direction, gear81is rotated in the same first direction, causing rotation of the gear84in a second opposite direction due to the intermeshed teeth of gears81and84. Lead screw86is operatively connected to gear84so that rotation of gear84causes rotation of lead screw86in the same direction. The power pack90includes a battery33which can be rechargeable outside the stapler when the power pack90is removed. The power pack90in some embodiments can include a power switch which is activated, i.e., turned on, by the clinician to start the motor and effect staple firing. In other embodiments, the motor can automatically turn on when fully loaded or upon actuation of another control on the stapler housing. Connected to the end of lead screw86(the end opposite the connection to the gear84) is a drive mechanism80which is configured to move in a linear motion (in an axial direction) along the lead screw86in response to rotation of the lead screw86. Drive mechanism80includes a flag or yoke identical to yoke42of power pack35discussed above, which engages the flange or boss44of firing rod46within the loading unit. The connection of the flag to the firing rod, the motor and gear mechanism, and the drive mechanism80of power pack90are the same as the power pack35and therefore the aforedescribed functions and features/components of power pack35for staple firing are fully applicable to the function and features/components of power pack90for staple firing so for brevity are not fully repeated herein. It should also be appreciated that the alternative mechanisms for motor powered stapled firing, such as the various belt drive mechanisms discussed above and/or illustrated in the Figures, can also be used in the power pack90to effect staple firing. Additionally, the various sensors discussed above with regard to sensing the firing stroke can also be provided in power pack90for the same uses. Power pack90also has an articulation assembly that includes a powering assembly including a motor96connected to a planetary gear box93configured to gear down the output of the motor96. The planetary gear box93drives a lead screw98through gears91,92operatively connected to the motor shaft. More specifically, upon rotation of the motor shaft by motor96in a first direction, gear91is rotated in the same first direction, causing rotation of the gear92in a second opposite direction due to the intermeshed teeth of gears92and91. Lead screw98is operatively connected to gear92so that rotation of gear92causes rotation of lead screw98in the same direction. The power pack90in some embodiments can include a power switch which is activated, i.e., turned on, by the clinician to start the motor and effect articulation. Connected to the end of lead screw98(the end opposite the connection to the gear92) is a drive mechanism95configured to move in a linear motion (in an axial direction) along the lead screw98in response to rotation of the lead screw98. For example, the drive mechanism95, like drive mechanism40described above, may include internal threads that engage external threads of the lead screw98and may include slides engaged in a track that prevent the drive mechanism95from rotating and therefore cause the drive mechanism95to move linearly (axially) in response to rotation of the lead screw98. As depicted, the power pack90has a compact configuration as the lead screw98extends alongside, slightly spaced from, the motor96and gear box93, i.e., both the motor96/gear box93and lead screw98extending longitudinally with the lead screw98parallel to the motor96. The drive mechanism95is connected to a proximal end of lead screw98. The drive mechanism95has an articulation rod engagement feature in the form of a flange or yoke94extending therefrom having legs99band a recess99ato engage an articulation rod79movable within the elongated member51of the loading unit. In the illustrated embodiment, the articulation rod79includes a flange or boss78which is engageable by the flag94. The output flag94can engage the bossed end78of the articulation tube79in substantially the same manner as the output flag42engages the bossed end44of the firing rod46as discussed above. The articulation assembly of the power pack90is oriented in the opposite direction from the staple firing assembly to minimize the space required in the power pack90, thereby providing the power pack with a compact configuration. As can be appreciated by reference toFIG.9D, the drive assembly80and associated flag82are at a proximal end of the assembly for firing staples with the lead screw86extending distally toward the gears81,84. The driving assembly95with associated flag94of the assembly for articulation are at a distal end with the lead screw98extending proximally toward gears91,92. Also, as can be appreciated by reference to the orientation ofFIG.9D, the articulation assembly is above the firing assembly, and the articulation assembly in the illustrated embodiment is positioned axially proximal of gears81,84and axially distal of drive mechanism80, radially spaced from lead screw86. The power pack90, like power pack35can have features/structure to constrain the motors84and96. These include for example spaced apart proximal and distal rails like proximal and distal rails97a,97bofFIG.9B, wherein gear box93can be seated within the proximal rails and the motor can be seated within the distal rails, the rails retaining the motor and preventing axial and rotational movement within the housing of power pack90. Bearing or bushings like bushings71a,71bofFIG.8Fcan also be provided to constrain the lead screw98at opposing ends, while allowing rotation thereof, thereby also constraining the motor. Other features can additionally or alternatively be provided to restrain the motor from axial movement while allowing rotation of the lead screw. Upon loading of the power pack90, the flag of the drive mechanism80of the staple firing assembly engages flange76of firing rod75and flag94of drive mechanism95of the articulation assembly engages flange or bossed end78of articulation rod79. Actuation of the motor96effects linear motion of the flag94which moves the articulation rod79linearly (axially). The articulation rod79is either directly coupled to the joint54, or coupled to another member or multiple members which are coupled to the joint54. When moved linearly, the articulation rod79effects movement of the jaws52a,52bof the stapler10to angular positions with respect to the longitudinal axis of the stapler. Note the articulation drive assembly operates in a similar manner as the firing drive assembly of power pack35in that when the power pack90is secured to the tube79by the second output flag94, linear motion generated at the second output flag94is transferred to linear motion of the tube79. Note that the joint54could be configured to provide movement about multiple axis, e.g., two or three axes, and could even be configured to provide unconstrained movement. Actuation of the motor83effects linear motion of the flag of drive mechanism80which moves the firing rod46linearly (axially). The firing rod either extends through the elongated portion51of the loading unit50for engagement of the firing mechanism in the jaw52aor is coupled to another elongated component(s) extending through the elongated portion51to engage the firing mechanism in the jaw52a. Note that the articulation rod or tube79can be configured to receive the firing rod so that the firing rod46can move within the tube79to effect firing and the articulation rod79can slide linearly over the firing rod to effect articulation. After use, the cover can be opened and the power pack90removed and charged while the handle assembly17(and stapler10) is sterilized or disposed of if the stapler is a disposable instrument. The power pack90, like power pack35described above, may be reused without requiring sterilization by being inserted into the receptacle of the now-sterilized handle assembly or a different sterile handle assembly. Thus, the removable power pack90, like power pack35, does not need to be subjected to the sterilization process and, therefore, contact between the harsh temperatures and/or chemicals of the sterilization process is advantageously avoided. One or more seals can be utilized for sealing power pack35and power pack90within the handle assembly17so that the power pack remains sterile and is not exposed to bodily fluids during surgical procedures. For example, as discussed above, in the stapler ofFIG.2B, a top seal is positioned at the interface between the cover27aand the housing29of the handle assembly where the cover27acloses for sealing the opening into the receptacle27band, therefore, power pack35or90from the environment when positioned therein. Further seals can be provided to further seal the receptacle and thus the power pack such as an O-ring placed around the articulation rod79to seal the space around the rod79and a flexible trigger seal surrounding the lever of the actuator24′ for sealing the internal components of the handle assembly throughout the range of positions of the movable lever24′. Additional seals can be provided to prevent flow of body fluid through the elongated member51and endoscopic portion16. As noted above, the power pack90can be used with the other staplers disclosed herein, e.g. circular staplers, linear staplers, as well as other instruments wherein two powered functions are desired. The first motor assembly can effect linear motion of a first elongated member to effect a first function of the stapler, e.g., clamping, articulation, firing, and the second motor assembly can effect linear motion of a second elongated member to effect a second different function of the stapler, e.g., clamping, articulation, firing. In the embodiment ofFIG.9D, one function is articulation and another function is staple firing. Note the power pack90can also be used with surgical instruments other than surgical staplers such as those illustrated inFIGS.16and17A-17F. The proximally loaded loading units of the present disclosure can include various end effectors to achieve various functions. They can be offered in a kit containing two or more differently functioning loading units, i.e., differently functioning jaws.FIG.16provides one example of a kit having two loading units: Loading unit170has a pair of scissors and loading unit175has a pair of graspers. More specifically, loading unit170has a handle portion171, an elongated portion172and jaws173a,173bwhich are connected to a clamping member extending through elongated portion172. Movement of the clamping member (clamping rod) within the elongated portion172moves the jaws173a,173bbetween open and closed positions to cut tissue between the jaws173a,173b. Loading unit175has a handle portion176, an elongated portion177and jaws178a,178bwhich are connected to a clamping member extending through elongated portion177. Movement of the clamping member (clamping rod) within the elongated portion177moves the jaws178a,178bbetween open and closed positions to grasp tissue between the jaws178a,178b. The jaws178a,178bcan have grasping surfaces that can include teeth, roughened surfaces, ribs, etc. The loading units170and175are insertable and removable through a proximal opening195in the instrument190(as in proximal openings23and29adescribed above) while the instrument remains in the body. The instrument190can be manually actuated, i.e., by squeezing handle194towards handle196, to effect clamping of the jaws of the loaded loading unit when inserted into the instrument190, as handle192operatively engages the clamping member to effect its linear movement. This engagement can be via a rack and pawl as inFIG.15. Alternatively, the instrument190can be powered by a power pack loaded into the compartment of the stapler in the same manner as power pack30or35described below, with the proximal opening within the compartment. The power pack drive mechanisms, e.g., an output flag or yoke like flag42, would extend through the slot in handle portions171,176to engage the clamping member within the loading unit to effect movement of the jaws toward each other. Either one of the jaws can be movable, i.e., pivotable, or both jaws can be movable (pivotable) toward and away from each other, for movement between closed and open positions It should be appreciated thatFIG.16is just one example of a kit as kits with other combinations of loading units, (and any number of loading units) including loading units containing fasteners, can be provided which are proximally loaded into the instrument in the same manner as loading unit50so that various loading units, or loading units that are reloaded with fasteners, can be removed and reinserted while the instrument remains in situ. Alternate jaw assemblies of the proximally loaded loading units are shown inFIGS.17C-17Fby way of example, it being understood that other jaw assemblies could be provided. Jaw assembly180provides shears for dissecting tissue, jaw assembly182provides graspers to grasp tissue, and jaw assembly184is a bipolar dissector to provide electrosurgical energy to tissue grasped between the jaws. InFIG.17D, instead of jaws, a hook186for monopolar cautery extends from the elongated member of the proximally loaded loading unit. InFIG.17E, the jaws188crimp a surgical clip189about tissue. InFIG.17F, the proximally loaded loading unit has an advancer within the elongated member to apply surgical tacks to tissue. It should be appreciated that the aforedescribed variations of the power packs can also be used with the surgical instruments ofFIGS.16-17Fso one or more functions can be powered by the motor. Alternatively, the instruments ofFIGS.16-17Fcan be manually powered. The power packs disclosed herein can be used in surgery where the clinician manually clamps the jaws and actuates the motor or motors to provide powered staple firing and/or powered jaw articulation or other functions. It is also contemplated that the power packs30,35and90can be used with automated robotic driven surgical staplers wherein clamping, motor actuation and any other functions of the instrument are performed robotically, including remote robotic control. This is shown for example inFIGS.6C and6D. Robotic arm160has a base162that is rotatable 360 degrees, an arm164connected to the base which moves in a clockwise or counterclockwise direction, and an arm166extending from arm164which swivels in a motion simulating a person's wrist to provide various degrees of freedom to manipulate the stapler. InFIG.6C, the stapler is shown held in arm164of robotic arm160prior to proximal loading of the loading unit50(or other loading units described herein) into the stapler168(which can be identical to stapler10or other staplers disclosed herein).FIG.6Dillustrates the stapler168after the loading unit50(or other loading units described herein) are proximally loaded into the stapler168. The degrees of freedom of the arms and base described herein are one example of the robotic arm design that can be utilized as other movements for the base and arms are also contemplated. The robotic arm can also be utilized for the other instruments disclosed herein, e.g., circular staplers, scissors, graspers, etc. Thus, whether robotically positioned or manually positioned by the user, the present disclosure provides a method for reloading a surgical fastener applier wherein the surgical fastener applier is maintained in a body, e.g., body cavity of a patient, while a) a first loading unit is proximally withdrawn through a proximal opening in the surgical fastener applier and b) a second loading unit is inserted in a distal direction through the proximal opening in the surgical fastener applier. The loading units each have an elongated member, first and second jaws at a distal portion of the elongated member and a firing mechanism movable within the elongated member from a first position to effect firing of fasteners into the tissue clamped between the first and second jaws. The loading units can alternatively have other jaws, e.g., graspers, scissors, etc. for effecting different surgical functions. In some embodiments, elements such as the rotational member and handle actuator may be omitted and a controller may be configured to generate signals or commands to be received by the surgical stapler in order to actuate the jaws, rotate the tubular shaft or perform other functions. Such a controller may be part of the surgical stapler device or located remotely. The handle assembly and/or motor assembly may be in wired or wireless communication with an external controller that includes inputs for controlling the surgical stapler Although the apparatus and methods of the subject disclosure have been described with respect to preferred embodiments, those skilled in the art will readily appreciate that changes and modifications may be made thereto without departing from the spirit and scope of the present disclosure as defined by the appended claims.

11857187

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate certain embodiments of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner. DETAILED DESCRIPTION The Applicant of the present application also owns the U.S. patent applications identified below which are each herein incorporated by reference in their respective entirety:U.S. patent application Ser. No. 12/894,311, entitled SURGICAL INSTRUMENTS WITH RECONFIGURABLE SHAFT SEGMENTS, now U.S. Pat. No. 8,763,877;U.S. patent application Ser. No. 12/894,340, entitled SURGICAL STAPLE CARTRIDGES SUPPORTING NON-LINEARLY ARRANGED STAPLES AND SURGICAL STAPLING INSTRUMENTS WITH COMMON STAPLE-FORMING POCKETS, now U.S. Pat. No. 8,899,463;U.S. patent application Ser. No. 12/894,327, entitled JAW CLOSURE ARRANGEMENTS FOR SURGICAL INSTRUMENTS, now U.S. Pat. No. 8,978,956;U.S. patent application Ser. No. 12/894,351, entitled SURGICAL CUTTING AND FASTENING INSTRUMENTS WITH SEPARATE AND DISTINCT FASTENER DEPLOYMENT AND TISSUE CUTTING SYSTEMS, now U.S. Pat. No. 9,113,864;U.S. patent application Ser. No. 12/894,338, entitled IMPLANTABLE FASTENER CARTRIDGE HAVING A NON-UNIFORM ARRANGEMENT, now U.S. Pat. No. 8,864,007;U.S. patent application Ser. No. 12/894,369, entitled IMPLANTABLE FASTENER CARTRIDGE COMPRISING A SUPPORT RETAINER, now U.S. Patent Application Publication No. 2012/0080344;U.S. patent application Ser. No. 12/894,312, entitled IMPLANTABLE FASTENER CARTRIDGE COMPRISING MULTIPLE LAYERS, now U.S. Pat. No. 8,925,782;U.S. patent application Ser. No. 12/894,377, entitled SELECTIVELY ORIENTABLE IMPLANTABLE FASTENER CARTRIDGE, now U.S. Pat. No. 8,393,514;U.S. patent application Ser. No. 12/894,339, entitled SURGICAL STAPLING INSTRUMENT WITH COMPACT ARTICULATION CONTROL ARRANGEMENT, now U.S. Pat. No. 8,840,003;U.S. patent application Ser. No. 12/894,360, entitled SURGICAL STAPLING INSTRUMENT WITH A VARIABLE STAPLE FORMING SYSTEM, now U.S. Pat. No. 9,113,862;U.S. patent application Ser. No. 12/894,322, entitled SURGICAL STAPLING INSTRUMENT WITH INTERCHANGEABLE STAPLE CARTRIDGE ARRANGEMENTS, now U.S. Pat. No. 8,740,034;U.S. patent application Ser. No. 12/894,350, entitled SURGICAL STAPLE CARTRIDGES WITH DETACHABLE SUPPORT STRUCTURES AND SURGICAL STAPLING INSTRUMENTS WITH SYSTEMS FOR PREVENTING ACTUATION MOTIONS WHEN A CARTRIDGE IS NOT PRESENT, now U.S. Patent Application Publication No. 2012/0080478;U.S. patent application Ser. No. 12/894,383, entitled IMPLANTABLE FASTENER CARTRIDGE COMPRISING BIOABSORBABLE LAYERS, now U.S. Pat. No. 8,752,699;U.S. patent application Ser. No. 12/894,389, entitled COMPRESSIBLE FASTENER CARTRIDGE, now U.S. Pat. No. 8,740,037;U.S. patent application Ser. No. 12/894,345, entitled FASTENERS SUPPORTED BY A FASTENER CARTRIDGE SUPPORT, now U.S. Pat. No. 8,783,542;U.S. patent application Ser. No. 12/894,306, entitled COLLAPSIBLE FASTENER CARTRIDGE, now U.S. Pat. No. 9,044,227;U.S. patent application Ser. No. 12/894,318, entitled FASTENER SYSTEM COMPRISING A PLURALITY OF CONNECTED RETENTION MATRIX ELEMENTS, now U.S. Pat. No. 8,814,024;U.S. patent application Ser. No. 12/894,330, entitled FASTENER SYSTEM COMPRISING A RETENTION MATRIX AND AN ALIGNMENT MATRIX, now U.S. Pat. No. 8,757,465;U.S. patent application Ser. No. 12/894,361, entitled FASTENER SYSTEM COMPRISING A RETENTION MATRIX, now U.S. Pat. No. 8,529,600;U.S. patent application Ser. No. 12/894,367, entitled FASTENING INSTRUMENT FOR DEPLOYING A FASTENER SYSTEM COMPRISING A RETENTION MATRIX, now U.S. Pat. No. 9,033,203;U.S. patent application Ser. No. 12/894,388, entitled FASTENER SYSTEM COMPRISING A RETENTION MATRIX AND A COVER, now U.S. Pat. No. 8,474,677;U.S. patent application Ser. No. 12/894,376, entitled FASTENER SYSTEM COMPRISING A PLURALITY OF FASTENER CARTRIDGES, now U.S. Pat. No. 9,044,228;U.S. patent application Ser. No. 13/097,865, entitled SURGICAL STAPLER ANVIL COMPRISING A PLURALITY OF FORMING POCKETS, now U.S. Pat. No. 9,295,464;U.S. patent application Ser. No. 13/097,936, entitled TISSUE THICKNESS COMPENSATOR FOR A SURGICAL STAPLER, now U.S. Pat. No. 8,657,176;U.S. patent application Ser. No. 13/097,954, entitled STAPLE CARTRIDGE COMPRISING A VARIABLE THICKNESS COMPRESSIBLE PORTION, now U.S. Pat. No. 10,136,890;U.S. patent application Ser. No. 13/097,856, entitled STAPLE CARTRIDGE COMPRISING STAPLES POSITIONED WITHIN A COMPRESSIBLE PORTION THEREOF, now U.S. Patent Application Publication No. 2012/0080336;U.S. patent application Ser. No. 13/097,928, entitled TISSUE THICKNESS COMPENSATOR COMPRISING DETACHABLE PORTIONS, now U.S. Pat. No. 8,746,535;U.S. patent application Ser. No. 13/097,891, entitled TISSUE THICKNESS COMPENSATOR FOR A SURGICAL STAPLER COMPRISING AN ADJUSTABLE ANVIL, now U.S. Pat. No. 8,864,009;U.S. patent application Ser. No. 13/097,948, entitled STAPLE CARTRIDGE COMPRISING AN ADJUSTABLE DISTAL PORTION, now U.S. Pat. No. 8,978,954;U.S. patent application Ser. No. 13/097,907, entitled COMPRESSIBLE STAPLE CARTRIDGE ASSEMBLY, now U.S. Pat. No. 9,301,755;U.S. patent application Ser. No. 13/097,861, entitled TISSUE THICKNESS COMPENSATOR COMPRISING PORTIONS HAVING DIFFERENT PROPERTIES, now U.S. Pat. No. 9,113,865;U.S. patent application Ser. No. 13/097,869, entitled STAPLE CARTRIDGE LOADING ASSEMBLY, now U.S. Pat. No. 8,857,694;U.S. patent application Ser. No. 13/097,917, entitled COMPRESSIBLE STAPLE CARTRIDGE COMPRISING ALIGNMENT MEMBERS, now U.S. Pat. No. 8,777,004;U.S. patent application Ser. No. 13/097,873, entitled STAPLE CARTRIDGE COMPRISING A RELEASABLE PORTION, now U.S. Pat. No. 8,740,038;U.S. patent application Ser. No. 13/097,938, entitled STAPLE CARTRIDGE COMPRISING COMPRESSIBLE DISTORTION RESISTANT COMPONENTS, now U.S. Pat. No. 9,016,542;U.S. patent application Ser. No. 13/097,924, entitled STAPLE CARTRIDGE COMPRISING A TISSUE THICKNESS COMPENSATOR, now U.S. Pat. No. 9,168,038;U.S. patent application Ser. No. 13/242,029, entitled SURGICAL STAPLER WITH FLOATING ANVIL, now U.S. Pat. No. 8,893,949;U.S. patent application Ser. No. 13/242,066, entitled CURVED END EFFECTOR FOR A STAPLING INSTRUMENT, now U.S. Patent Application Publication No. 2012/0080498;U.S. patent application Ser. No. 13/242,086, entitled STAPLE CARTRIDGE INCLUDING COLLAPSIBLE DECK, now U.S. Pat. No. 9,055,941;U.S. patent application Ser. No. 13/241,912, entitled STAPLE CARTRIDGE INCLUDING COLLAPSIBLE DECK ARRANGEMENT, now U.S. Pat. No. 9,050,084;U.S. patent application Ser. No. 13/241,922, entitled SURGICAL STAPLER WITH STATIONARY STAPLE DRIVERS, now U.S. Pat. No. 9,216,019;U.S. patent application Ser. No. 13/241,637, entitled SURGICAL INSTRUMENT WITH TRIGGER ASSEMBLY FOR GENERATING MULTIPLE ACTUATION MOTIONS, now U.S. Pat. No. 8,789,741; andU.S. patent application Ser. No. 13/241,629, entitled SURGICAL INSTRUMENT WITH SELECTIVELY ARTICULATABLE END EFFECTOR, now U.S. Patent Application Publication No. 2012/0074200. The Applicant of the present application also owns the U.S. patent applications identified below which were filed on Mar. 28, 2012 and which are each herein incorporated by reference in their respective entirety:U.S. application Ser. No. 13/433,096, entitled TISSUE THICKNESS COMPENSATOR COMPRISING A PLURALITY OF CAPSULES, now U.S. Pat. No. 9,301,752;U.S. application Ser. No. 13/433,103, entitled TISSUE THICKNESS COMPENSATOR COMPRISING A PLURALITY OF LAYERS, now U.S. Pat. No. 9,433,419;U.S. application Ser. No. 13/433,098, entitled EXPANDABLE TISSUE THICKNESS COMPENSATOR, now U.S. Pat. No. 9,301,753;U.S. application Ser. No. 13/433,102, entitled TISSUE THICKNESS COMPENSATOR COMPRISING A RESERVOIR, now U.S. Pat. No. 9,232,941;U.S. application Ser. No. 13/433,114, entitled RETAINER ASSEMBLY INCLUDING A TISSUE THICKNESS COMPENSATOR, now U.S. Pat. No. 9,386,988;U.S. application Ser. No. 13/433,136, entitled TISSUE THICKNESS COMPENSATOR COMPRISING AT LEAST ONE MEDICAMENT, now U.S. Pat. No. 9,839,420;U.S. application Ser. No. 13/433,144, entitled TISSUE THICKNESS COMPENSATOR COMPRISING FIBERS TO PRODUCE A RESILIENT LOAD, now U.S. Pat. No. 9,277,919;U.S. application Ser. No. 13/433,148, entitled TISSUE THICKNESS COMPENSATOR COMPRISING STRUCTURE TO PRODUCE A RESILIENT LOAD, now U.S. Pat. No. 9,220,500;U.S. application Ser. No. 13/433,155, entitled TISSUE THICKNESS COMPENSATOR COMPRISING RESILIENT MEMBERS, now U.S. Pat. No. 9,480,476;U.S. application Ser. No. 13/433,163, entitled METHODS FOR FORMING TISSUE THICKNESS COMPENSATOR ARRANGEMENTS FOR SURGICAL STAPLERS, now U.S. Patent Application Publication No. 2012/0248169;U.S. application Ser. No. 13/433,167, entitled TISSUE THICKNESS COMPENSATORS, now U.S. Pat. No. 9,220,501;U.S. application Ser. No. 13/433,175, entitled LAYERED TISSUE THICKNESS COMPENSATOR, now U.S. Pat. No. 9,332,974;U.S. application Ser. No. 13/433,179, entitled TISSUE THICKNESS COMPENSATORS FOR CIRCULAR SURGICAL STAPLERS, now U.S. Pat. No. 9,364,233;U.S. application Ser. No. 13/433,115, entitled TISSUE THICKNESS COMPENSATOR COMPRISING CAPSULES DEFINING A LOW PRESSURE ENVIRONMENT, now U.S. Pat. No. 9,204,880;U.S. application Ser. No. 13/433,118, entitled TISSUE THICKNESS COMPENSATOR COMPRISED OF A PLURALITY OF MATERIALS, now U.S. Pat. No. 9,414,838;U.S. application Ser. No. 13/433,135, entitled MOVABLE MEMBER FOR USE WITH A TISSUE THICKNESS COMPENSATOR, now U.S. Pat. No. 9,517,063;U.S. application Ser. No. 13/433,129, entitled TISSUE THICKNESS COMPENSATOR COMPRISING A PLURALITY OF MEDICAMENTS, now U.S. Pat. No. 9,211,120;U.S. application Ser. No. 13/433,140, entitled TISSUE THICKNESS COMPENSATOR AND METHOD FOR MAKING THE SAME, now U.S. Pat. No. 9,241,714;U.S. application Ser. No. 13/433,147, entitled TISSUE THICKNESS COMPENSATOR COMPRISING CHANNELS, now U.S. Pat. No. 9,351,730;U.S. application Ser. No. 13/433,126, entitled TISSUE THICKNESS COMPENSATOR COMPRISING TISSUE INGROWTH FEATURES, now U.S. Pat. No. 9,320,523; andU.S. application Ser. No. 13/433,132, entitled DEVICES AND METHODS FOR ATTACHING TISSUE THICKNESS COMPENSATING MATERIALS TO SURGICAL STAPLING INSTRUMENTS, now U.S. Patent Application Publication No. 2013/0256373. Certain exemplary embodiments will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the devices and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those of ordinary skill in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments and that the scope of the various embodiments of the present invention is defined solely by the claims. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present invention. Reference throughout the specification to “various embodiments,” “some embodiments,” “one embodiment,” or “an embodiment”, or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in various embodiments,” “in some embodiments,” “in one embodiment”, or “in an embodiment”, or the like, in places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, the particular features, structures, or characteristics illustrated or described in connection with one embodiment may be combined, in whole or in part, with the features structures, or characteristics of one or more other embodiments without limitation. Such modifications and variations are intended to be included within the scope of the present invention. The terms “proximal” and “distal” are used herein with reference to a clinician manipulating the handle portion of the surgical instrument. The term “proximal” referring to the portion closest to the clinician and the term “distal” referring to the portion located away from the clinician. It will be further appreciated that, for convenience and clarity, spatial terms such as “vertical”, “horizontal”, “up”, and “down” may be used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and/or absolute. Various exemplary devices and methods are provided for performing laparoscopic and minimally invasive surgical procedures. However, the person of ordinary skill in the art will readily appreciate that the various methods and devices disclosed herein can be used in numerous surgical procedures and applications including, for example, in connection with open surgical procedures. As the present Detailed Description proceeds, those of ordinary skill in the art will further appreciate that the various instruments disclosed herein can be inserted into a body in any way, such as through a natural orifice, through an incision or puncture hole formed in tissue, etc. The working portions or end effector portions of the instruments can be inserted directly into a patient's body or can be inserted through an access device that has a working channel through which the end effector and elongated shaft of a surgical instrument can be advanced. Turning to the Drawings wherein like numerals denote like components throughout the several views,FIG.1depicts a surgical instrument10that is capable of practicing several unique benefits. The surgical stapling instrument10is designed to manipulate and/or actuate various forms and sizes of end effectors12that are operably attached thereto. In the embodiment depicted inFIGS.1-1E, for example, the end effector12includes an elongated channel14that forms a lower jaw13of the end effector12. The elongated channel14is configured to support an “implantable” staple cartridge30and also movably support an anvil20that functions as an upper jaw15of the end effector12. In various embodiments, the elongated channel14may be fabricated from, for example, 300 & 400 Series, 17-4 & 17-7 stainless steel, titanium, etc. and be formed with spaced side walls16. The anvil20may be fabricated from, for example, 300 & 400 Series, 17-4 & 17-7 stainless steel, titanium, etc. and have a staple forming undersurface, generally labeled as22that has a plurality of staple forming pockets23formed therein. SeeFIGS.1B-1E. In addition, the anvil20has a bifurcated ramp assembly24that protrudes proximally therefrom. An anvil pin26protrudes from each lateral side of the ramp assembly24to be received within a corresponding slot or opening18in the side walls16of the elongated channel14to facilitate its movable or pivotable attachment thereto. Various forms of implantable staple cartridges may be employed with the various embodiments of the surgical instruments disclosed herein. Specific staple cartridge configurations and constructions will be discussed in further detail below. However, in the embodiment depicted inFIG.1A, an implantable staple cartridge30is shown. In at least one embodiment, the staple cartridge30has a body portion31that consists of a compressible hemostat material such as, for example, oxidized regenerated cellulose (“ORC”) or a bio-absorbable foam in which lines of unformed metal staples32are supported. In at least some embodiments, in order to prevent the staple from being affected and the hemostat material from being activated during the introduction and positioning process, the entire cartridge may be coated or wrapped in a biodegradable film38such as a polydioxanon film sold under the trademark PDS® or with a Polyglycerol sebacate (PGS) film or other biodegradable films formed from PGA (Polyglycolic acid, marketed under the trade mark Vicryl), PCL (Polycaprolactone), PLA or PLLA (Polylactic acid), PHA (polyhydroxyalkanoate), PGCL (poliglecaprone 25, sold under the trademark Monocryl) or a composite of PGA, PCL, PLA, PDS that would be impermeable until ruptured. The body31of staple cartridge30is sized to be removably supported within the elongated channel14as shown such that each staple32therein is aligned with corresponding staple forming pockets23in the anvil when the anvil20is driven into forming contact with the staple cartridge30. In use, once the end effector12has been positioned adjacent the target tissue, the end effector12is manipulated to capture or clamp the target tissue between an upper face36of the staple cartridge30and the staple forming surface22of the anvil20. The staples32are formed by moving the anvil20in a path that is substantially parallel to the elongated channel14to bring the staple forming surface22and, more particularly, the staple forming pockets23therein into substantially simultaneous contact with the upper face36of the staple cartridge30. As the anvil20continues to move into the staple cartridge30, the legs34of the staples32contact a corresponding staple forming pocket23in anvil20which serves to bend the staple legs34over to form the staples32into a “B shape”. Further movement of the anvil20toward the elongated channel14will further compress and form the staples32to a desired final formed height “FF”. The above-described staple forming process is generally depicted inFIGS.1B-1E. For example,FIG.1Billustrates the end effector12with target tissue “T” between the anvil20and the upper face36of the implantable staple cartridge30.FIG.1Cillustrates the initial clamping position of the anvil20wherein the anvil has20been closed onto the target tissue “T” to clamp the target tissue “T” between the anvil20and the upper face36of the staple cartridge30.FIG.1Dillustrates the initial staple formation wherein the anvil20has started to compress the staple cartridge30such that the legs34of the staples32are starting to be formed by the staple forming pockets23in the anvil20.FIG.1Eillustrates the staple32in its final formed condition through the target tissue “T” with the anvil20removed for clarity purposes. Once the staples32have been formed and fastened to the target tissue “T”, the surgeon will move the anvil20to the open position to enable the cartridge body31and the staples32to remain affixed to the target tissue while the end effector12is being withdrawn from the patient. The end effector12forms all of the staples simultaneously as the two jaws13,15are clamped together. The remaining “crushed” body materials31act as both a hemostat (the ORC) and a staple line reinforcement (PGA, PDS or any of the other film compositions mentioned above 38). Also, since the staples32never have to leave the cartridge body31during forming, the likelihood of the staples32being malformed during forming is minimized. As used herein the term “implantable” means that, in addition to the staples, the cartridge body materials that support the staples will also remain in the patient and may eventually be absorbed by the patient's body. Such implantable staple cartridges are distinguishable from prior cartridge arrangements that remain positioned within the end effector in their entirety after they have been fired. In various implementations, the end effector12is configured to be coupled to an elongated shaft assembly40that protrudes from a handle assembly100. The end effector12(when closed) and the elongated shaft assembly40may have similar cross-sectional shapes and be sized to operably pass through a trocar tube or working channel in another form of access instrument. As used herein, the term “operably pass” means that the end effector and at least a portion of the elongated shaft assembly may be inserted through or passed through the channel or tube opening and can be manipulated therein as needed to complete the surgical stapling procedure. In some embodiments, when in a closed position, the jaws13and15of the end effector12may provide the end effector with a roughly circular cross-sectional shape that facilitates its passage through a circular passage/opening. However, the end effectors of various embodiments of the present invention, as well as the elongated shaft assembly embodiments, could conceivably be provided with other cross-sectional shapes that could otherwise pass through access passages and openings that have non-circular cross-sectional shapes. Thus, an overall size of a cross-section of a closed end effector will be related to the size of the passage or opening through which it is intended to pass. Thus, one end effector for example, may be referred to as a “5 mm” end effector which means it can operably pass through an opening that is at least approximately 5 mm in diameter. In various embodiments, the elongated shaft assembly40may have an outer diameter that is substantially the same as the outer diameter of the end effector12when in a closed position. For example, a 5 mm end effector may be coupled to an elongated shaft assembly40that has 5 mm cross-sectional diameter. However, as the present Detailed Description proceeds, it will become apparent that various embodiments of the present may be effectively used in connection with different sizes of end effectors. For example, a 10 mm end effector may be attached to an elongated shaft that has a 5 mm cross-sectional diameter. Conversely, for those applications wherein a 10 mm or larger access opening or passage is provided, the elongated shaft assembly40may have a 10 mm (or larger) cross-sectional diameter, but may also be able to actuate a 5 mm or 10 mm end effector. Accordingly, the outer shaft40may have an outer diameter that is the same as or is different from the outer diameter of a closed end effector12attached thereto. As depicted, the elongated shaft assembly40extends distally from the handle assembly100in a generally straight line to define a longitudinal axis A-A. In various embodiments, for example, the elongated shaft assembly40may be approximately 9-16 inches (229-406 mm) long. However, the elongated shaft assembly40may be provided in other lengths and, in other embodiments, may have joints therein or be otherwise configured to facilitate articulation of the end effector12relative to other portions of the shaft or handle assembly as will be discussed in further detail below. In various embodiments, the elongated shaft assembly40includes a spine member50that extends from the handle assembly100to the end effector12. The proximal end of the elongated channel14of the end effector12has a pair of retention trunnions17protruding therefrom that are sized to be received within corresponding trunnion openings or cradles52that are provided in a distal end of the spine member50to enable the end effector12to be removably coupled the elongated shaft assembly40. The spine member50may be fabricated from, for example, 6061 or 7075 aluminum, stainless steel, titanium, etc. In various embodiments, the handle assembly100comprises a pistol grip-type housing that may be fabricated in two or more pieces for assembly purposes. For example, the handle assembly100as shown comprises a right hand case member102and a left hand case member (not illustrated) that are molded or otherwise fabricated from a polymer or plastic material and are designed to mate together. Such case members may be attached together by snap features, pegs and sockets molded or otherwise formed therein and/or by adhesive, screws, etc. The spine member50has a proximal end54that has a flange56formed thereon. The flange56is configured to be rotatably supported within a groove106formed by mating ribs108that protrude inwardly from each of the case members102,104. Such arrangement facilitates the attachment of the spine member50to the handle assembly100while enabling the spine member50to be rotated relative to the handle assembly100about the longitudinal axis A-A in a 360° path. As can be further seen inFIG.1, the spine member50passes through and is supported by a mounting bushing60that is rotatably affixed to the handle assembly100. The mounting bushing60has a proximal flange62and a distal flange64that define a rotational groove65that is configured to rotatably receive a nose portion101of the handle assembly100therebetween. Such arrangement enables the mounting bushing60to rotate about longitudinal axis A-A relative to the handle assembly100. The spine member50is non-rotatably pinned to the mounting bushing60by a spine pin66. In addition, a rotation knob70is attached to the mounting bushing60. In one embodiment, for example, the rotation knob70has a hollow mounting flange portion72that is sized to receive a portion of the mounting bushing60therein. In various embodiments, the rotation knob70may be fabricated from, for example, glass or carbon filled Nylon, polycarbonate, Ultem®, etc. and is affixed to the mounting bushing60by the spine pin66as well. In addition, an inwardly protruding retention flange74is formed on the mounting flange portion72and is configured to extend into a radial groove68formed in the mounting bushing60. Thus, the surgeon may rotate the spine member50(and the end effector12attached thereto) about longitudinal axis A-A in a 360° path by grasping the rotation knob70and rotating it relative to the handle assembly100. In various embodiments, the anvil20is retained in an open position by an anvil spring21and/or another biasing arrangement. The anvil20is selectively movable from the open position to various closed or clamping and firing positions by a firing system, generally designated as109. The firing system109includes a “firing member”110which, in various embodiments, comprises a hollow firing tube110. The hollow firing tube110is axially movable on the spine member50and thus forms the outer portion of the elongated shaft assembly40. The firing tube110may be fabricated from a polymer or other suitable material and have a proximal end that is attached to a firing yoke114of the firing system109. In various embodiments for example, the firing yoke114may be over-molded to the proximal end of the firing tube110. However, other fastener arrangements may be employed. As can be seen inFIG.1, the firing yoke114may be rotatably supported within a support collar120that is configured to move axially within the handle assembly100. In various embodiments, the support collar120has a pair of laterally extending fins that are sized to be slidably received within fin slots formed in the right and left hand case members. Thus, the support collar120may slide axially within the handle housing100while enabling the firing yoke114and firing tube110to rotate relative thereto about the longitudinal axis A-A. In various embodiments, a longitudinal slot is provided through the firing tube110to enable the spine pin66to extend therethrough into the spine member50while facilitating the axial travel of the firing tube110on the spine member50. The firing system109further comprises a firing trigger130which serves to control the axial travel of the firing tube110on the spine member50. SeeFIG.1. Such axial movement in the distal direction of the firing tube110into firing interaction with the anvil20is referred to herein as “firing motion”. As can be seen inFIG.1, the firing trigger130is movably or pivotally coupled to the handle assembly100by a pivot pin132. A torsion spring135is employed to bias the firing trigger130away from the pistol grip portion107of the handle assembly100to an un-actuated “open” or starting position. As can be seen inFIG.1, the firing trigger130has an upper portion134that is movably attached to (pinned) firing links136that are movably attached to (pinned) the support collar120. Thus, movement of the firing trigger130from the starting position (FIG.1) toward an ending position adjacent the pistol grip portion107of the handle assembly100will cause the firing yoke114and the firing tube110to move in the distal direction “DD”. Movement of the firing trigger130away from the pistol grip portion107of the handle assembly100(under the bias of the torsion spring135) will cause the firing yoke114and firing tube110to move in the proximal direction “PD” on the spine member50. Various embodiments of the present invention may be employed with different sizes and configurations of implantable staple cartridges. For example, the surgical instrument10, when used in connection with a first firing adapter140, may be used with a 5 mm end effector12that is approximately 20 mm long (or in other lengths) which supports an implantable staple cartridge30. Such end effector size may be particularly well-suited, for example, to complete relatively fine dissection and vascular transactions. However, as will be discussed in further detail below, the surgical instrument10may also be employed, for example, in connection with other sizes of end effectors and staple cartridges by replacing the first firing adapter140with a second firing adapter. In still other embodiments, the elongated shaft assembly40may configured to be attached to only one form or size of end effector. One method of removably coupling the end effector12to the spine member50will now be explained. The coupling process is commenced by inserting the retention trunnions17on the elongated channel14into the trunnion cradles52in the spine member50. Thereafter, the surgeon advances the firing trigger130toward the pistol grip107of the housing assembly100to distally advance the firing tube110and the first firing adapter140over a proximal end portion47of the elongated channel14to thereby retain the trunnions17in their respective cradles52. Such position of the first firing adapter140over the trunnions17is referred to herein as the “coupled position”. Various embodiments of the present invention may also have an end effector locking assembly for locking the firing trigger130in position after an end effector12has been attached to the spine member50. More specifically, one embodiment of the end effector locking assembly160includes a retention pin162that is movably supported in the upper portion134of the firing trigger130. As discussed above, the firing tube110must initially be advanced distally to the coupled position wherein the first firing adapter140retains the retention trunnions17of the end effector12in the trunnion cradles52in the spine member50. The surgeon advances the firing adapter140distally to the coupled position by pulling the firing trigger130from the starting position toward the pistol grip107. As the firing trigger130is initially actuated, the retention pin162is moved distally until the firing tube110has advanced the first firing adapter140to the coupled position at which point the retention pin162is biased into a locking cavity164formed in the case member. In various embodiments, when the retention pin162enters into the locking cavity164, the pin162may make an audible “click” or other sound, as well as provide a tactile indication to the surgeon that the end effector12has been “locked” onto the spine member50. In addition, the surgeon cannot inadvertently continue to actuate the firing trigger130to start to form staples32in the end effector12without intentionally biasing the retention pin162out of the locking cavity164. Similarly, if the surgeon releases the firing trigger130when in the coupled position, it is retained in that position by the retention pin162to prevent the firing trigger130from returning to the starting position and thereby releasing the end effector12from the spine member50. Various embodiments of the present invention may further include a firing system lock button137that is pivotally attached to the handle assembly100. In one form, the firing system lock button137has a latch138formed on a distal end thereof that is oriented to engage the firing yoke114when the firing release button is in a first latching position. As can be seen inFIG.1, a latch spring139serves to bias the firing system lock button137to the first latching position. In various circumstances, the latch138serves to engage the firing yoke114at a point where the position of the firing yoke114on the spine member50corresponds to a point wherein the first firing adapter140is about to distally advance up the clamping ramp28on the anvil20. It will be understood that, as the first firing adapter140advances axially up the clamping ramp28, the anvil20will move in a path such that its staple forming surface portion22is substantially parallel to the upper face36of the staple cartridge30. After the end effector12has been coupled to the spine member50, the staple forming process is commenced by first depressing the firing system lock button137to enable the firing yoke114to be further moved distally on the spine member50and ultimately compress the anvil20into the staple cartridge30. After depressing the firing system lock button137, the surgeon continues to actuate the firing trigger130towards the pistol grip107thereby driving the first staple collar140up the corresponding staple forming ramp29to force the anvil20into forming contact with the staples32in the staple cartridge30. The firing system lock button137prevents the inadvertent forming of the staples32until the surgeon is ready to start that process. In this embodiment, the surgeon must depress the firing system lock button137before the firing trigger130may be further actuated to begin the staple forming process. The surgical instrument10may be solely used as a tissue stapling device if so desired. However, various embodiments of the present invention may also include a tissue cutting system, generally designated as170. In at least one form, the tissue cutting system170comprises a knife member172that may be selectively advanced from an un-actuated position adjacent the proximal end of the end effector12to an actuated position by actuating a knife advancement trigger200. The knife member172is movably supported within the spine member50and is attached or otherwise protrudes from a knife rod180. The knife member172may be fabricated from, for example, 420 or 440 stainless steel with a hardness of greater than 38HRC (Rockwell Hardness C-scale) and have a tissue cutting edge176formed on the distal end174thereof and be configured to slidably extend through a slot in the anvil20and a centrally disposed slot33in the staple cartridge30to cut through tissue that is clamped in the end effector12. In various embodiments, the knife rod180extends through the spine member50and has a proximal end portion which drivingly interfaces with a knife transmission that is operably attached to the knife advance trigger200. In various embodiments, the knife advance trigger200is attached to pivot pin132such that it may be pivoted or otherwise actuated without actuating the firing trigger130. In various embodiments, a first knife gear192is also attached to the pivot pin132such that actuation of the knife advance trigger200also pivots the first knife gear192. A firing return spring202is attached between the first knife gear192and the handle housing100to bias the knife advancement trigger200to a starting or un-actuated position. Various embodiments of the knife transmission also include a second knife gear194that is rotatably supported on a second gear spindle and in meshing engagement with the first knife gear192. The second knife gear194is in meshing engagement with a third knife gear196that is supported on a third gear spindle. Also supported on the third gear spindle195is a fourth knife gear198. The fourth knife gear198is adapted to drivingly engage a series of annular gear teeth or rings on a proximal end of the knife rod180. Thus, such arrangement enables the fourth knife gear198to axially drive the knife rod180in the distal direction “DD” or proximal direction “PD” while enabling the firing rod180to rotate about longitudinal axis A-A with respect to the fourth knife gear198. Accordingly, the surgeon may axially advance the firing rod180and ultimately the knife member172distally by pulling the knife advancement trigger200towards the pistol grip107of the handle assembly100. Various embodiments of the present invention further include a knife lockout system210that prevents the advancement of the knife member172unless the firing trigger130has been pulled to the fully fired position. Such feature will therefore prevent the activation of the knife advancement system170unless the staples have first been fired or formed into the tissue. As can be seen inFIG.1, various implementations of the knife lockout system210comprise a knife lockout bar211that is pivotally supported within the pistol grip portion107of the handle assembly100. The knife lockout bar211has an activation end212that is adapted to be engaged by the firing trigger130when the firing trigger130is in the fully fired position. In addition, the knife lockout bar211has a retaining hook214on its other end that is adapted to hookingly engage a latch rod216on the first cut gear192. A knife lock spring218is employed to bias the knife lockout bar211to a “locked” position wherein the retaining hook214is retained in engagement with the latch rod216to thereby prevent actuation of the knife advancement trigger200unless the firing trigger130is in the fully fired position. After the staples have been “fired” (formed) into the target tissue, the surgeon may depress the firing trigger release button167to enable the firing trigger130to return to the starting position under the bias of the torsion spring135which enables the anvil20to be biased to an open position under the bias of spring21. When in the open position, the surgeon may withdraw the end effector12leaving the implantable staple cartridge30and staples32behind. In applications wherein the end effector was inserted through a passage, working channel, etc. the surgeon will return the anvil20to the closed position by activating the firing trigger130to enable the end effector12to be withdrawn out through the passage or working channel. If, however, the surgeon desires to cut the target tissue after firing the staples, the surgeon activates the knife advancement trigger200in the above-described manner to drive the knife bar172through the target tissue to the end of the end effector. Thereafter, the surgeon may release the knife advancement trigger200to enable the firing return spring202to cause the firing transmission to return the knife bar172to the starting (un-actuated) position. Once the knife bar172has been returned to the starting position, the surgeon may open the end effector jaws13,15to release the implantable cartridge30within the patient and then withdraw the end effector12from the patient. Thus, such surgical instruments facilitate the use of small implantable staple cartridges that may be inserted through relatively smaller working channels and passages, while providing the surgeon with the option to fire the staples without cutting tissue or if desired to also cut tissue after the staples have been fired. Various unique and novel embodiments of the present invention employ a compressible staple cartridge that supports staples in a substantially stationary position for forming contact by the anvil. In various embodiments, the anvil is driven into the unformed staples wherein, in at least one such embodiment, the degree of staple formation attained is dependent upon how far the anvil is driven into the staples. Such an arrangement provides the surgeon with the ability to adjust the amount of forming or firing pressure applied to the staples and thereby alter the final formed height of the staples. In other various embodiments of the present invention, surgical stapling arrangements can employ staple driving elements which can lift the staples toward the anvil. Such embodiments are described in greater detail further below. In various embodiments, with regard to the embodiments described in detail above, the amount of firing motion that is applied to the movable anvil is dependent upon the degree of actuation of the firing trigger. For example, if the surgeon desires to attain only partially formed staples, then the firing trigger is only partially depressed inward towards the pistol grip107. To attain more staple formation, the surgeon simply compresses the firing trigger further which results in the anvil being further driven into forming contact with the staples. As used herein, the term “forming contact” means that the staple forming surface or staple forming pockets have contacted the ends of the staple legs and have started to form or bend the legs over into a formed position. The degree of staple formation refers to how far the staple legs have been folded over and ultimately relates to the forming height of the staple as referenced above. Those of ordinary skill in the art will further understand that, because the anvil20moves in a substantially parallel relationship with respect to the staple cartridge as the firing motions are applied thereto, the staples are formed substantially simultaneously with substantially the same formed heights. FIGS.2and3illustrate an alternative end effector12″ that is similar to the end effector12′ described above, except with the following differences that are configured to accommodate a knife bar172′. The knife bar172′ is coupled to or protrudes from a knife rod180and is otherwise operated in the above described manner with respect to the knife bar172. However, in this embodiment, the knife bar172′ is long enough to traverse the entire length of the end effector12″ and therefore, a separate distal knife member is not employed in the end effector12″. The knife bar172′ has an upper transverse member173′ and a lower transverse member175′ formed thereon. The upper transverse member173′ is oriented to slidably transverse a corresponding elongated slot250in anvil20″ and the lower transverse member175′ is oriented to traverse an elongated slot252in the elongated channel14″ of the end effector12″. A disengagement slot (not shown) is also provided in the anvil20″ such that when the knife bar172′ has been driven to an ending position within end effector12″, the upper transverse member173′ drops through the corresponding slot to enable the anvil20″ to move to the open position to disengage the stapled and cut tissue. The anvil20″ may be otherwise identical to anvil20described above and the elongated channel14″ may be otherwise identical to elongated channel14described above. In these embodiments, the anvil20″ is biased to a fully open position (FIG.2) by a spring or other opening arrangement (not shown). The anvil20″ is moved between the open and fully clamped positions by the axial travel of the firing adapter150in the manner described above. Once the firing adapter150has been advanced to the fully clamped position (FIG.3), the surgeon may then advance the knife bar172″ distally in the manner described above. If the surgeon desires to use the end effector as a grasping device to manipulate tissue, the firing adapter may be moved proximally to allow the anvil20″ to move away from the elongated channel14″ as represented inFIG.4in broken lines. In this embodiment, as the knife bar172″ moves distally, the upper transverse member173′ and the lower transverse member175′ draw the anvil20″ and elongated channel14″ together to achieve the desired staple formation as the knife bar172″ is advanced distally through the end effector12″. SeeFIG.5. Thus, in this embodiment, staple formation occurs simultaneously with tissue cutting, but the staples themselves may be sequentially formed as the knife bar172″ is driven distally. The unique and novel features of the various surgical staple cartridges and the surgical instruments of the present invention enable the staples in those cartridges to be arranged in one or more linear or non-linear lines. A plurality of such staple lines may be provided on each side of an elongated slot that is centrally disposed within the staple cartridge for receiving the tissue cutting member therethrough. In one arrangement, for example, the staples in one line may be substantially parallel with the staples in adjacent line(s) of staples, but offset therefrom. In still other embodiments, one or more lines of staples may be non-linear in nature. That is, the base of at least one staple in a line of staples may extend along an axis that is substantially transverse to the bases of other staples in the same staple line. For example, the lines of staples on each side of the elongated slot may have a zigzag appearance. In various embodiments, a staple cartridge can comprise a cartridge body and a plurality of staples stored within the cartridge body. In use, the staple cartridge can be introduced into a surgical site and positioned on a side of the tissue being treated. In addition, a staple-forming anvil can be positioned on the opposite side of the tissue. In various embodiments, the anvil can be carried by a first jaw and the staple cartridge can be carried by a second jaw, wherein the first jaw and/or the second jaw can be moved toward the other. Once the staple cartridge and the anvil have been positioned relative to the tissue, the staples can be ejected from the staple cartridge body such that the staples can pierce the tissue and contact the staple-forming anvil. Once the staples have been deployed from the staple cartridge body, the staple cartridge body can then be removed from the surgical site. In various embodiments disclosed herein, a staple cartridge, or at least a portion of a staple cartridge, can be implanted with the staples. In at least one such embodiment, as described in greater detail further below, a staple cartridge can comprise a cartridge body which can be compressed, crushed, and/or collapsed by the anvil when the anvil is moved from an open position into a closed position. When the cartridge body is compressed, crushed, and/or collapsed, the staples positioned within the cartridge body can be deformed by the anvil. Alternatively, the jaw supporting the staple cartridge can be moved toward the anvil into a closed position. In either event, in various embodiments, the staples can be deformed while they are at least partially positioned within the cartridge body. In certain embodiments, the staples may not be ejected from the staple cartridge while, in some embodiments, the staples can be ejected from the staple cartridge along with a portion of the cartridge body. Referring now toFIGS.6A-6D, a compressible staple cartridge, such as staple cartridge1000, for example, can comprise a compressible, implantable cartridge body1010and, in addition, a plurality of staples1020positioned in the compressible cartridge body1010, although only one staple1020is depicted inFIGS.6A-6D.FIG.6Aillustrates the staple cartridge1000supported by a staple cartridge support, or staple cartridge channel,1030, wherein the staple cartridge1000is illustrated in an uncompressed condition. In such an uncompressed condition, the anvil1040may or may not be in contact with the tissue T. In use, the anvil1040can be moved from an open position into contact with the tissue T as illustrated inFIG.6Band position the tissue T against the cartridge body1010. Even though the anvil1040can position the tissue T against a tissue-contacting surface1019of staple cartridge body1010, referring again toFIG.6B, the staple cartridge body1010may be subjected to little, if any, compressive force or pressure at such point and the staples1020may remain in an unformed, or unfired, condition. As illustrated inFIGS.6A and6B, the staple cartridge body1010can comprise one or more layers and the staple legs1021of staples1020can extend upwardly through these layers. In various embodiments, the cartridge body1010can comprise a first layer1011, a second layer1012, a third layer1013, wherein the second layer1012can be positioned intermediate the first layer1011and the third layer1013, and a fourth layer1014, wherein the third layer1013can be positioned intermediate the second layer1012and the fourth layer1014. In at least one embodiment, the bases1022of the staples1020can be positioned within cavities1015in the fourth layer1014and the staple legs1021can extend upwardly from the bases1022and through the fourth layer1014, the third layer1013, and the second layer1012, for example. In various embodiments, each deformable leg1021can comprise a tip, such as sharp tip1023, for example, which can be positioned in the second layer1012, for example, when the staple cartridge1000is in an uncompressed condition. In at least one such embodiment, the tips1023may not extend into and/or through the first layer1011, wherein, in at least one embodiment, the tips1023may not protrude through the tissue-contacting surface1019when the staple cartridge1000is in an uncompressed condition. In certain other embodiments, the sharp tips1023may be positioned in the third layer1013, and/or any other suitable layer, when the staple cartridge is in an uncompressed condition. In various alternative embodiments, a cartridge body of a staple cartridge may have any suitable number of layers such as less than four layers or more than four layers, for example. In various embodiments, as described in greater detail below, the first layer1011can be comprised of a buttress material and/or plastic material, such as polydioxanone (PDS) and/or polyglycolic acid (PGA), for example, and the second layer1012can be comprised of a bioabsorbable foam material and/or a compressible haemostatic material, such as oxidized regenerated cellulose (ORC), for example. In various embodiments, one or more of the first layer1011, the second layer1012, the third layer1013, and the fourth layer1014may hold the staples1020within the staple cartridge body1010and, in addition, maintain the staples1020in alignment with one another. In various embodiments, the third layer1013can be comprised of a buttress material, or a fairly incompressible or inelastic material, which can be configured to hold the staple legs1021of the staples1020in position relative to one another. Furthermore, the second layer1012and the fourth layer1014, which are positioned on opposite sides of the third layer1013, can stabilize, or reduce the movement of, the staples1020even though the second layer1012and the fourth layer1014can be comprised of a compressible foam or elastic material. In certain embodiments, the staple tips1023of the staple legs1021can be at least partially embedded in the first layer1011. In at least one such embodiment, the first layer1011and the third layer1013can be configured to co-operatively and firmly hold the staple legs1021in position. In at least one embodiment, the first layer1011and the third layer1013can each be comprised of a sheet of bioabsorbable plastic, such as polyglycolic acid (PGA) which is marketed under the trade name Vicryl, polylactic acid (PLA or PLLA), polydioxanone (PDS), polyhydroxyalkanoate (PHA), poliglecaprone 25 (PGCL) which is marketed under the trade name Monocryl, polycaprolactone (PCL), and/or a composite of PGA, PLA, PDS, PHA, PGCL and/or PCL, for example, and the second layer1012and the fourth layer1014can each be comprised of at least one haemostatic material or agent. Although the first layer1011can be compressible, the second layer1012can be substantially more compressible than the first layer1011. For example, the second layer1012can be about twice as compressible, about three times as compressible, about four times as compressible, about five times as compressible, and/or about ten times as compressible, for example, as the first layer1011. Stated another way, the second layer1012may compress about two times, about three times, about four times, about five times, and/or about ten times as much as first layer1011, for a given force. In certain embodiments, the second layer1012can be between about twice as compressible and about ten times as compressible, for example, as the first layer1011. In at least one embodiment, the second layer1012can comprise a plurality of air voids defined therein, wherein the amount and/or size of the air voids in the second layer1012can be controlled in order to provide a desired compressibility of the second layer1012. Similar to the above, although the third layer1013can be compressible, the fourth layer1014can be substantially more compressible than the third layer1013. For example, the fourth layer1014can be about twice as compressible, about three times as compressible, about four times as compressible, about five times as compressible, and/or about ten times as compressible, for example, as the third layer1013. Stated another way, the fourth layer1014may compress about two times, about three times, about four times, about five times, and/or about ten times as much as third layer1013, for a given force. In certain embodiments, the fourth layer1014can be between about twice as compressible and about ten times as compressible, for example, as the third layer1013. In at least one embodiment, the fourth layer1014can comprise a plurality of air voids defined therein, wherein the amount and/or size of the air voids in the fourth layer1014can be controlled in order to provide a desired compressibility of the fourth layer1014. In various circumstances, the compressibility of a cartridge body, or cartridge body layer, can be expressed in terms of a compression rate, i.e., a distance in which a layer is compressed for a given amount of force. For example, a layer having a high compression rate will compress a larger distance for a given amount of compressive force applied to the layer as compared to a layer having a lower compression rate. This being said, the second layer1012can have a higher compression rate than the first layer1011and, similarly, the fourth layer1014can have a higher compression rate than the third layer1013. In various embodiments, the second layer1012and the fourth layer1014can be comprised of the same material and can comprise the same compression rate. In various embodiments, the second layer1012and the fourth layer1014can be comprised of materials having different compression rates. Similarly, the first layer1011and the third layer1013can be comprised of the same material and can comprise the same compression rate. In certain embodiments, the first layer1011and the third layer1013can be comprised of materials having different compression rates. As the anvil1040is moved toward its closed position, the anvil1040can contact tissue T and apply a compressive force to the tissue T and the staple cartridge1000, as illustrated inFIG.6C. In such circumstances, the anvil1040can push the top surface, or tissue-contacting surface1019, of the cartridge body1010downwardly toward the staple cartridge support1030. In various embodiments, the staple cartridge support1030can comprise a cartridge support surface1031which can be configured to support the staple cartridge1000as the staple cartridge1000is compressed between the cartridge support surface1031and the tissue-contacting surface1041of anvil1040. Owing to the pressure applied by the anvil1040, the cartridge body1010can be compressed and the anvil1040can come into contact with the staples1020. More particularly, in various embodiments, the compression of the cartridge body1010and the downward movement of the tissue-contacting surface1019can cause the tips1023of the staple legs1021to pierce the first layer1011of cartridge body1010, pierce the tissue T, and enter into forming pockets1042in the anvil1040. As the cartridge body1010is further compressed by the anvil1040, the tips1023can contact the walls defining the forming pockets1042and, as a result, the legs1021can be deformed or curled inwardly, for example, as illustrated inFIG.6C. As the staple legs1021are being deformed, as also illustrated inFIG.6C, the bases1022of the staples1020can be in contact with or supported by the staple cartridge support1030. In various embodiments, as described in greater detail below, the staple cartridge support1030can comprise a plurality of support features, such as staple support grooves, slots, or troughs1032, for example, which can be configured to support the staples1020, or at least the bases1022of the staples1020, as the staples1020are being deformed. As also illustrated inFIG.6C, the cavities1015in the fourth layer1014can collapse as a result of the compressive force applied to the staple cartridge body1010. In addition to the cavities1015, the staple cartridge body1010can further comprise one or more voids, such as voids1016, for example, which may or may not comprise a portion of a staple positioned therein, that can be configured to allow the cartridge body1010to collapse. In various embodiments, the cavities1015and/or the voids1016can be configured to collapse such that the walls defining the cavities and/or walls deflect downwardly and contact the cartridge support surface1031and/or contact a layer of the cartridge body1010positioned underneath the cavities and/or voids. Upon comparingFIG.6BandFIG.6C, it is evident that the second layer1012and the fourth layer1014have been substantially compressed by the compressive pressure applied by the anvil1040. It may also be noted that the first layer1011and the third layer1013have been compressed as well. As the anvil1040is moved into its closed position, the anvil1040may continue to further compress the cartridge body1010by pushing the tissue-contacting surface1019downwardly toward the staple cartridge support1030. As the cartridge body1010is further compressed, the anvil1040can deform the staples1020into their completely-formed shape as illustrated inFIG.6D. Referring toFIG.6D, the legs1021of each staple1020can be deformed downwardly toward the base1022of each staple1020in order to capture at least a portion of the tissue T, the first layer1011, the second layer1012, the third layer1013, and the fourth layer1014between the deformable legs1021and the base1022. Upon comparingFIGS.6C and6D, it is further evident that the second layer1012and the fourth layer1014have been further substantially compressed by the compressive pressure applied by the anvil1040. It may also be noted upon comparingFIGS.6C and6Dthat the first layer1011and the third layer1013have been further compressed as well. After the staples1020have been completely, or at least sufficiently, formed, the anvil1040can be lifted away from the tissue T and the staple cartridge support1030can be moved away, and/or detached from, the staple cartridge1000. As depicted inFIG.6D, and as a result of the above, the cartridge body1010can be implanted with the staples1020. In various circumstances, the implanted cartridge body1010can support the tissue along the staple line. In some circumstances, a haemostatic agent, and/or any other suitable therapeutic medicament, contained within the implanted cartridge body1010can treat the tissue over time. A haemostatic agent, as mentioned above, can reduce the bleeding of the stapled and/or incised tissue while a bonding agent or tissue adhesive can provide strength to the tissue over time. The implanted cartridge body1010can be comprised of materials such as ORC (oxidized regenerated cellulose), extracellular proteins such as collagen, polyglycolic acid (PGA) which is marketed under the trade name Vicryl, polylactic acid (PLA or PLLA), polydioxanone (PDS), polyhydroxyalkanoate (PHA), poliglecaprone 25 (PGCL) which is marketed under the trade name Monocryl, polycaprolactone (PCL), and/or a composite of PGA, PLA, PDS, PHA, PGCL and/or PCL, for example. In certain circumstances, the cartridge body1010can comprise an antibiotic and/or anti-microbial material, such as colloidal silver and/or triclosan, for example, which can reduce the possibility of infection in the surgical site. In various embodiments, the layers of the cartridge body1010can be connected to one another. In at least one embodiment, the second layer1012can be adhered to the first layer1011, the third layer1013can be adhered to the second layer1012, and the fourth layer1014can be adhered to the third layer1013utilizing at least one adhesive, such as fibrin and/or protein hydrogel, for example. In certain embodiments, although not illustrated, the layers of the cartridge body1010can be connected together by interlocking mechanical features. In at least one such embodiment, the first layer1011and the second layer1012can each comprise corresponding interlocking features, such as a tongue and groove arrangement and/or a dovetail joint arrangement, for example. Similarly, the second layer1012and the third layer1013can each comprise corresponding interlocking features while the third layer1013and the fourth layer1014can each comprise corresponding interlocking features. In certain embodiments, although not illustrated, the staple cartridge1000can comprise one or more rivets, for example, which can extend through one or more layers of the cartridge body1010. In at least one such embodiment, each rivet can comprise a first end, or head, positioned adjacent to the first layer1011and a second head positioned adjacent to the fourth layer1014which can be either assembled to or formed by a second end of the rivet. Owing to the compressible nature of the cartridge body1010, in at least one embodiment, the rivets can compress the cartridge body1010such that the heads of the rivets can be recessed relative to the tissue-contacting surface1019and/or the bottom surface1018of the cartridge body1010, for example. In at least one such embodiment, the rivets can be comprised of a bioabsorbable material, such as polyglycolic acid (PGA) which is marketed under the trade name Vicryl, polylactic acid (PLA or PLLA), polydioxanone (PDS), polyhydroxyalkanoate (PHA), poliglecaprone 25 (PGCL) which is marketed under the trade name Monocryl, polycaprolactone (PCL), and/or a composite of PGA, PLA, PDS, PHA, PGCL and/or PCL, for example. In certain embodiments, the layers of the cartridge body1010may not be connected to one another other than by the staples1020contained therein. In at least one such embodiment, the frictional engagement between the staple legs1021and the cartridge body1010, for example, can hold the layers of the cartridge body1010together and, once the staples have been formed, the layers can be captured within the staples1020. In certain embodiments, at least a portion of the staple legs1021can comprise a roughened surface or rough coating which can increase the friction forces between the staples1020and the cartridge body1010. As described above, a surgical instrument can comprise a first jaw including the staple cartridge support1030and a second jaw including the anvil1040. In various embodiments, as described in greater detail further below, the staple cartridge1000can comprise one or more retention features which can be configured to engage the staple cartridge support1030and, as a result, releasably retain the staple cartridge1000to the staple cartridge support1030. In certain embodiments, the staple cartridge1000can be adhered to the staple cartridge support1030by at least one adhesive, such as fibrin and/or protein hydrogel, for example. In use, in at least one circumstance, especially in laparoscopic and/or endoscopic surgery, the second jaw can be moved into a closed position opposite the first jaw, for example, such that the first and second jaws can be inserted through a trocar into a surgical site. In at least one such embodiment, the trocar can define an approximately 5 mm aperture, or cannula, through which the first and second jaws can be inserted. In certain embodiments, the second jaw can be moved into a partially-closed position intermediate the open position and the closed position which can allow the first and second jaws to be inserted through the trocar without deforming the staples1020contained in the staple cartridge body1010. In at least one such embodiment, the anvil1040may not apply a compressive force to the staple cartridge body1010when the second jaw is in its partially-closed intermediate position while, in certain other embodiments, the anvil1040can compress the staple cartridge body1010when the second jaw is in its partially-closed intermediate position. Even though the anvil1040can compress the staple cartridge body1010when it is in such an intermediate position, the anvil1040may not sufficiently compress the staple cartridge body1010such that the anvil1040comes into contact with the staples1020and/or such that the staples1020are deformed by the anvil1040. Once the first and second jaws have been inserted through the trocar into the surgical site, the second jaw can be opened once again and the anvil1040and the staple cartridge1000can be positioned relative to the targeted tissue as described above. In various embodiments, referring now toFIGS.7A-7D, an end effector of a surgical stapler can comprise an implantable staple cartridge1100positioned intermediate an anvil1140and a staple cartridge support1130. Similar to the above, the anvil1140can comprise a tissue-contacting surface1141, the staple cartridge1100can comprise a tissue-contacting surface1119, and the staple cartridge support1130can comprise a support surface1131which can be configured to support the staple cartridge1100. Referring toFIG.7A, the anvil1140can be utilized to position the tissue T against the tissue contacting surface1119of staple cartridge1100without deforming the staple cartridge1100and, when the anvil1140is in such a position, the tissue-contacting surface1141can be positioned a distance1101aaway from the staple cartridge support surface1131and the tissue-contacting surface1119can be positioned a distance1102aaway from the staple cartridge support surface1131. Thereafter, as the anvil1140is moved toward the staple cartridge support1130, referring now toFIG.7B, the anvil1140can push the top surface, or tissue-contacting surface1119, of staple cartridge1100downwardly and compress the first layer1111and the second layer1112of cartridge body1110. As the layers1111and1112are compressed, referring again toFIG.7B, the second layer1112can be crushed and the legs1121of staples1120can pierce the first layer1111and enter into the tissue T. In at least one such embodiment, the staples1120can be at least partially positioned within staple cavities, or voids,1115in the second layer1112and, when the second layer1112is compressed, the staple cavities1115can collapse and, as a result, allow the second layer1112to collapse around the staples1120. In various embodiments, the second layer1112can comprise cover portions1116which can extend over the staple cavities1115and enclose, or at least partially enclose, the staple cavities1115.FIG.7Billustrates the cover portions1116being crushed downwardly into the staple cavities1115. In certain embodiments, the second layer1112can comprise one or more weakened portions which can facilitate the collapse of the second layer1112. In various embodiments, such weakened portions can comprise score marks, perforations, and/or thin cross-sections, for example, which can facilitate a controlled collapse of the cartridge body1110. In at least one embodiment, the first layer1111can comprise one or more weakened portions which can facilitate the penetration of the staple legs1121through the first layer1111. In various embodiments, such weakened portions can comprise score marks, perforations, and/or thin cross-sections, for example, which can be aligned, or at least substantially aligned, with the staple legs1121. When the anvil1140is in a partially closed, unfired position, referring again toFIG.7A, the anvil1140can be positioned a distance1101aaway from the cartridge support surface1131such that a gap is defined therebetween. This gap can be filled by the staple cartridge1100, having a staple cartridge height1102a, and the tissue T. As the anvil1140is moved downwardly to compress the staple cartridge1100, referring again toFIG.7B, the distance between the tissue contacting surface1141and the cartridge support surface1131can be defined by a distance1101bwhich is shorter than the distance1101a. In various circumstances, the gap between the tissue-contacting surface1141of anvil1140and the cartridge support surface1131, defined by distance1101b, may be larger than the original, undeformed staple cartridge height1102a. As the anvil1140is moved closer to the cartridge support surface1131, referring now toFIG.7C, the second layer1112can continue to collapse and the distance between the staple legs1121and the forming pockets1142can decrease. Similarly, the distance between the tissue-contacting surface1141and the cartridge support surface1131can decrease to a distance1101cwhich, in various embodiments, may be greater than, equal to, or less than the original, undeformed cartridge height1102a. Referring now toFIG.7D, the anvil1140can be moved into a final, fired position in which the staples1120have been fully formed, or at least formed to a desired height. In such a position, the tissue-contacting surface1141of anvil1140can be a distance1101daway from the cartridge support surface1131, wherein the distance1101dcan be shorter than the original, undeformed cartridge height1102a. As also illustrated inFIG.7D, the staple cavities1115may be fully, or at least substantially, collapsed and the staples1120may be completely, or at least substantially, surrounded by the collapsed second layer1112. In various circumstances, the anvil1140can be thereafter moved away from the staple cartridge1100. Once the anvil1140has been disengaged from the staple cartridge1100, the cartridge body1110can at least partially re-expand in various locations, i.e., locations intermediate adjacent staples1120, for example. In at least one embodiment, the crushed cartridge body1110may not resiliently re-expand. In various embodiments, the formed staples1120and, in addition, the cartridge body1110positioned intermediate adjacent staples1120may apply pressure, or compressive forces, to the tissue T which may provide various therapeutic benefits. As discussed above, referring again to the embodiment illustrated inFIG.7A, each staple1120can comprise staple legs1121extending therefrom. Although staples1120are depicted as comprising two staple legs1121, various staples can be utilized which can comprise one staple leg or, alternatively, more than two staple legs, such as three staple legs or four staple legs, for example. As illustrated inFIG.7A, each staple leg1121can be embedded in the second layer1112of the cartridge body1110such that the staples1120are secured within the second layer1112. In various embodiments, the staples1120can be inserted into the staple cavities1115in cartridge body1110such that the tips1123of the staple legs1121enter into the cavities1115before the bases1122. After the tips1123have been inserted into the cavities1115, in various embodiments, the tips1123can be pressed into the cover portions1116and incise the second layer1112. In various embodiments, the staples1120can be seated to a sufficient depth within the second layer1112such that the staples1120do not move, or at least substantially move, relative to the second layer1112. In certain embodiments, the staples1120can be seated to a sufficient depth within the second layer1112such that the bases1122are positioned or embedded within the staple cavities1115. In various other embodiments, the bases1122may not be positioned or embedded within the second layer1112. In certain embodiments, referring again toFIG.7A, the bases1122may extend below the bottom surface1118of the cartridge body1110. In certain embodiments, the bases1122can rest on, or can be directly positioned against, the cartridge support surface1130. In various embodiments, the cartridge support surface1130can comprise support features extending therefrom and/or defined therein wherein, in at least one such embodiment, the bases1122of the staples1120may be positioned within and supported by one or more support grooves, slots, or troughs,1132, for example, in the staple cartridge support1130, as described in greater detail further below. In various embodiments, referring now toFIGS.8and9, a staple cartridge, such as staple cartridge1200, for example, can comprise a compressible, implantable cartridge body1210comprising an outer layer1211and an inner layer1212. Similar to the above, the staple cartridge1200can comprise a plurality of staples1220positioned within the cartridge body1210. In various embodiments, each staple1220can comprise a base1222and one or more staple legs1221extending therefrom. In at least one such embodiment, the staple legs1221can be inserted into the inner layer1212and seated to a depth in which the bases1222of the staples1220abut and/or are positioned adjacent to the bottom surface1218of the inner layer1212, for example. In the embodiment depicted inFIGS.8and9, the inner layer1212does not comprise staple cavities configured to receive a portion of the staples1220while, in other embodiments, the inner layer1212can comprise such staple cavities. In various embodiments, further to the above, the inner layer1212can be comprised of a compressible material, such as bioabsorbable foam and/or oxidized regenerated cellulose (ORC), for example, which can be configured to allow the cartridge body1210to collapse when a compressive load is applied thereto. In various embodiments, the inner layer1212can be comprised of a lyophilized foam comprising polylactic acid (PLA) and/or polyglycolic acid (PGA), for example. The ORC may be commercially available under the trade name Surgicel and can comprise a loose woven fabric (like a surgical sponge), loose fibers (like a cotton ball), and/or a foam. In at least one embodiment, the inner layer1212can be comprised of a material including medicaments, such as freeze-dried thrombin and/or fibrin, for example, contained therein and/or coated thereon which can be water-activated and/or activated by fluids within the patient's body, for example. In at least one such embodiment, the freeze-dried thrombin and/or fibrin can be held on a Vicryl (PGA) matrix, for example. In certain circumstances, however, the activatable medicaments can be unintentionally activated when the staple cartridge1200is inserted into a surgical site within the patient, for example. In various embodiments, referring again toFIGS.8and9, the outer layer1211can be comprised of a water impermeable, or at least substantially water impermeable, material such that liquids do not come into contact with, or at least substantially contact, the inner layer1212until after the cartridge body1210has been compressed and the staple legs have penetrated the outer layer1211and/or after the outer layer1211has been incised in some fashion. In various embodiments, the outer layer1211can be comprised of a buttress material and/or plastic material, such as polydioxanone (PDS) and/or polyglycolic acid (PGA), for example. In certain embodiments, the outer layer1211can comprise a wrap which surrounds the inner layer1212and the staples1220. More particularly, in at least one embodiment, the staples1220can be inserted into the inner layer1212and the outer layer1211can be wrapped around the sub-assembly comprising the inner layer1212and the staples1220and then sealed. In various embodiments described herein, the staples of a staple cartridge can be fully formed by an anvil when the anvil is moved into a closed position. In various other embodiments, referring now toFIGS.10-13, the staples of a staple cartridge, such as staple cartridge4100, for example, can be deformed by an anvil when the anvil is moved into a closed position and, in addition, by a staple driver system which moves the staples toward the closed anvil. The staple cartridge4100can comprise a compressible cartridge body4110which can be comprised of a foam material, for example, and a plurality of staples4120at least partially positioned within the compressible cartridge body4110. In various embodiments, the staple driver system can comprise a driver holder4160, a plurality of staple drivers4162positioned within the driver holder4160, and a staple cartridge pan4180which can be configured to retain the staple drivers4162in the driver holder4160. In at least one such embodiment, the staple drivers4162can be positioned within one or more slots4163in the driver holder4160wherein the sidewalls of the slots4163can assist in guiding the staple drivers4162upwardly toward the anvil. In various embodiments, the staples4120can be supported within the slots4163by the staple drivers4162wherein, in at least one embodiment, the staples4120can be entirely positioned in the slots4163when the staples4120and the staple drivers4162are in their unfired positions. In certain other embodiments, at least a portion of the staples4120can extend upwardly through the open ends4161of slots4163when the staples4120and staple drivers4162are in their unfired positions. In at least one such embodiment, referring primarily now toFIG.11, the bases of the staples4120can be positioned within the driver holder4160and the tips of the staples4120can be embedded within the compressible cartridge body4110. In certain embodiments, approximately one-third of the height of the staples4120can be positioned within the driver holder4160and approximately two-thirds of the height of the staples4120can be positioned within the cartridge body4110. In at least one embodiment, referring toFIG.10A, the staple cartridge4100can further comprise a water impermeable wrap or membrane4111surrounding the cartridge body4110and the driver holder4160, for example. In use, the staple cartridge4100can be positioned within a staple cartridge channel, for example, and the anvil can be moved toward the staple cartridge4100into a closed position. In various embodiments, the anvil can contact and compress the compressible cartridge body4110when the anvil is moved into its closed position. In certain embodiments, the anvil may not contact the staples4120when the anvil is in its closed position. In certain other embodiments, the anvil may contact the legs of the staples4120and at least partially deform the staples4120when the anvil is moved into its closed position. In either event, the staple cartridge4100can further comprise one or more sleds4170which can be advanced longitudinally within the staple cartridge4100such that the sleds4170can sequentially engage the staple drivers4162and move the staple drivers4162and the staples4120toward the anvil. In various embodiments, the sleds4170can slide between the staple cartridge pan4180and the staple drivers4162. In embodiments where the closure of the anvil has started the forming process of the staples4120, the upward movement of the staples4120toward the anvil can complete the forming process and deform the staples4120to their fully formed, or at least desired, height. In embodiments where the closure of the anvil has not deformed the staples4120, the upward movement of the staples4120toward the anvil can initiate and complete the forming process and deform the staples4120to their fully formed, or at least desired, height. In various embodiments, the sleds4170can be advanced from a proximal end of the staple cartridge4100to a distal end of the staple cartridge4100such that the staples4120positioned in the proximal end of the staple cartridge4100are fully formed before the staples4120positioned in the distal end of the staple cartridge4100are fully formed. In at least one embodiment, referring toFIG.12, the sleds4170can each comprise at least one angled or inclined surface4711which can be configured to slide underneath the staple drivers4162and lift the staple drivers4162as illustrated inFIG.13. In various embodiments, further to the above, the staples4120can be formed in order to capture at least a portion of the tissue T and at least a portion of the compressible cartridge body4110of the staple cartridge4100therein. After the staples4120have been formed, the anvil and the staple cartridge channel4130of the surgical stapler can be moved away from the implanted staple cartridge4100. In various circumstances, the cartridge pan4180can be fixedly engaged with the staple cartridge channel4130wherein, as a result, the cartridge pan4180can become detached from the compressible cartridge body4110as the staple cartridge channel4130is pulled away from the implanted cartridge body4110. In various embodiments, referring again toFIG.10, the cartridge pan4180can comprise opposing side walls4181between which the cartridge body4110can be removably positioned. In at least one such embodiment, the compressible cartridge body4110can be compressed between the side walls4181such that the cartridge body4110can be removably retained therebetween during use and releasably disengaged from the cartridge pan4180as the cartridge pan4180is pulled away. In at least one such embodiment, the driver holder4160can be connected to the cartridge pan4180such that the driver holder4160, the drivers4162, and/or the sleds4170can remain in the cartridge pan4180when the cartridge pan4180is removed from the surgical site. In certain other embodiments, the drivers4162can be ejected from the driver holder4160and left within the surgical site. In at least one such embodiment, the drivers4162can be comprised of a bioabsorbable material, such as polyglycolic acid (PGA) which is marketed under the trade name Vicryl, polylactic acid (PLA or PLLA), polydioxanone (PDS), polyhydroxyalkanoate (PHA), poliglecaprone 25 (PGCL) which is marketed under the trade name Monocryl, polycaprolactone (PCL), and/or a composite of PGA, PLA, PDS, PHA, PGCL and/or PCL, for example. In various embodiments, the drivers4162can be attached to the staples4120such that the drivers4162are deployed with the staples4120. In at least one such embodiment, each driver4162can comprise a trough configured to receive the bases of the staples4120, for example, wherein, in at least one embodiment, the troughs can be configured to receive the staple bases in a press-fit and/or snap-fit manner. In certain embodiments, further to the above, the driver holder4160and/or the sleds4170can be ejected from the cartridge pan4180. In at least one such embodiment, the sleds4170can slide between the cartridge pan4180and the driver holder4160such that, as the sleds4170are advanced in order to drive the staple drivers4162and staples4120upwardly, the sleds4170can move the driver holder4160upwardly out of the cartridge pan4180as well. In at least one such embodiment, the driver holder4160and/or the sleds4170can be comprised of a bioabsorbable material, such as polyglycolic acid (PGA) which is marketed under the trade name Vicryl, polylactic acid (PLA or PLLA), polydioxanone (PDS), polyhydroxyalkanoate (PHA), poliglecaprone 25 (PGCL) which is marketed under the trade name Monocryl, polycaprolactone (PCL), and/or a composite of PGA, PLA, PDS, PHA, PGCL and/or PCL, for example. In various embodiments, the sleds4170can be integrally formed and/or attached to a drive bar, or cutting member, which pushes the sleds4170through the staple cartridge4100. In such embodiments, the sleds4170may not be ejected from the cartridge pan4180and may remain with the surgical stapler while, in other embodiments in which the sleds4170are not attached to the drive bar, the sleds4170may be left in the surgical site. In any event, further to the above, the compressibility of the cartridge body4110can allow thicker staple cartridges to be used within an end effector of a surgical stapler as the cartridge body4110can compress, or shrink, when the anvil of the stapler is closed. In certain embodiments, as a result of the staples being at least partially deformed upon the closure of the anvil, taller staples, such as staples having an approximately 0.18″ staple height, for example, could be used, wherein approximately 0.12″ of the staple height can be positioned within the compressible layer4110and wherein the compressible layer4110can have an uncompressed height of approximately 0.14″, for example. In many embodiments described herein, a staple cartridge can comprise a plurality of staples therein. In various embodiments, such staples can be comprised of a metal wire deformed into a substantially U-shaped configuration having two staple legs. Other embodiments are envisioned in which staples can comprise different configurations such as two or more wires that have been joined together having three or more staple legs. In various embodiments, the wire, or wires, used to form the staples can comprise a round, or at least substantially round, cross-section. In at least one embodiment, the staple wires can comprise any other suitable cross-section, such as square and/or rectangular cross-sections, for example. In certain embodiments, the staples can be comprised of plastic wires. In at least one embodiment, the staples can be comprised of plastic-coated metal wires. In various embodiments, a cartridge can comprise any suitable type of fastener in addition to or in lieu of staples. In at least one such embodiment, such a fastener can comprise pivotable arms which are folded when engaged by an anvil. In certain embodiments, two-part fasteners could be utilized. In at least one such embodiment, a staple cartridge can comprise a plurality of first fastener portions and an anvil can comprise a plurality of second fastener portions which are connected to the first fastener portions when the anvil is compressed against the staple cartridge. In certain embodiments, as described above, a sled or driver can be advanced within a staple cartridge in order to complete the forming process of the staples. In certain embodiments, a sled or driver can be advanced within an anvil in order to move one or more forming members downwardly into engagement with the opposing staple cartridge and the staples, or fasteners, positioned therein. In various embodiments described herein, a staple cartridge can comprise four rows of staples stored therein. In at least one embodiment, the four staple rows can be arranged in two inner staple rows and two outer staple rows. In at least one such embodiment, an inner staple row and an outer staple row can be positioned on a first side of a cutting member, or knife, slot within the staple cartridge and, similarly, an inner staple row and an outer staple row can be positioned on a second side of the cutting member, or knife, slot. In certain embodiments, a staple cartridge may not comprise a cutting member slot; however, such a staple cartridge may comprise a designated portion configured to be incised by a cutting member in lieu of a staple cartridge slot. In various embodiments, the inner staple rows can be arranged within the staple cartridge such that they are equally, or at least substantially equally, spaced from the cutting member slot. Similarly, the outer staple rows can be arranged within the staple cartridge such that they are equally, or at least substantially equally, spaced from the cutting member slot. In various embodiments, a staple cartridge can comprise more than or less than four rows of staples stored within a staple cartridge. In at least one embodiment, a staple cartridge can comprise six rows of staples. In at least one such embodiment, the staple cartridge can comprise three rows of staples on a first side of a cutting member slot and three rows of staples on a second side of the cutting member slot. In certain embodiments, a staple cartridge may comprise an odd number of staple rows. For example, a staple cartridge may comprise two rows of staples on a first side of a cutting member slot and three rows of staples on a second side of the cutting member slot. In various embodiments, the staple rows can comprise staples having the same, or at least substantially the same, unformed staple height. In certain other embodiments, one or more of the staple rows can comprise staples having a different unformed staple height than the other staples. In at least one such embodiment, the staples on a first side of a cutting member slot may have a first unformed height and the staples on a second side of a cutting member slot may have a second unformed height which is different than the first height, for example. In various embodiments, as described above, a staple cartridge can comprise a cartridge body including a plurality of staple cavities defined therein. The cartridge body can comprise a deck and a top deck surface wherein each staple cavity can define an opening in the deck surface. As also described above, a staple can be positioned within each staple cavity such that the staples are stored within the cartridge body until they are ejected therefrom. Prior to being ejected from the cartridge body, in various embodiments, the staples can be contained with the cartridge body such that the staples do not protrude above the deck surface. As the staples are positioned below the deck surface, in such embodiments, the possibility of the staples becoming damaged and/or prematurely contacting the targeted tissue can be reduced. In various circumstances, the staples can be moved between an unfired position in which they do not protrude from the cartridge body and a fired position in which they have emerged from the cartridge body and can contact an anvil positioned opposite the staple cartridge. In various embodiments, the anvil, and/or the forming pockets defined within the anvil, can be positioned a predetermined distance above the deck surface such that, as the staples are being deployed from the cartridge body, the staples are deformed to a predetermined formed height. In some circumstances, the thickness of the tissue captured between the anvil and the staple cartridge may vary and, as a result, thicker tissue may be captured within certain staples while thinner tissue may be captured within certain other staples. In either event, the clamping pressure, or force, applied to the tissue by the staples may vary from staple to staple or vary between a staple on one end of a staple row and a staple on the other end of the staple row, for example. In certain circumstances, the gap between the anvil and the staple cartridge deck can be controlled such that the staples apply a certain minimum clamping pressure within each staple. In some such circumstances, however, significant variation of the clamping pressure within different staples may still exist. Surgical stapling instruments are disclosed in U.S. Pat. No. 7,380,696, which issued on Jun. 3, 2008, the entire disclosure of which is incorporated by reference herein. An illustrative multi-stroke handle for the surgical stapling and severing instrument is described in greater detail in the co-owned U.S. patent application entitled SURGICAL STAPLING INSTRUMENT INCORPORATING A MULTISTROKE FIRING POSITION INDICATOR AND RETRACTION MECHANISM, Ser. No. 10/674,026, now U.S. Pat. No. 7,364,061, the disclosure of which is hereby incorporated by reference in its entirety. Other applications consistent with the present invention may incorporate a single firing stroke, such as described in commonly owned U.S. patent application SURGICAL STAPLING INSTRUMENT HAVING SEPARATE DISTINCT CLOSING AND FIRING SYSTEMS, Ser. No. 10/441,632, now U.S. Pat. No. 7,000,818, the disclosure of which is hereby incorporated by reference in its entirety. In various embodiments described herein, a staple cartridge can comprise means for compensating for the thickness of the tissue captured within the staples deployed from the staple cartridge. In various embodiments, referring toFIG.14, a staple cartridge, such as staple cartridge10000, for example, can include a rigid first portion, such as support portion10010, for example, and a compressible second portion, such as tissue thickness compensator10020, for example. In at least one embodiment, referring primarily toFIG.16, the support portion10010can comprise a cartridge body, a top deck surface10011, and a plurality of staple cavities10012wherein, similar to the above, each staple cavity10012can define an opening in the deck surface10011. A staple10030, for example, can be removably positioned in each staple cavity10012. In at least one such embodiment, each staple10030can comprise a base10031and one or more legs10032extending from the base10031. Prior to the staples10030being deployed, as also described in greater detail below, the bases10031of the staples10030can be supported by staple drivers positioned within the support portion10010and, concurrently, the legs10032of the staples10030can be at least partially contained within the staple cavities10012. In various embodiments, the staples10030can be deployed between an unfired position and a fired position such that the legs10032move through the tissue thickness compensator10020, penetrate through a top surface of the tissue thickness compensator10020, penetrate the tissue T, and contact an anvil positioned opposite the staple cartridge10000. As the legs10032are deformed against the anvil, the legs10032of each staple10030can capture a portion of the tissue thickness compensator10020and a portion of the tissue T within each staple10030and apply a compressive force to the tissue. Further to the above, the legs10032of each staple10030can be deformed downwardly toward the base10031of the staple to form a staple entrapment area10039in which the tissue T and the tissue thickness compensator10020can be captured. In various circumstances, the staple entrapment area10039can be defined between the inner surfaces of the deformed legs10032and the inner surface of the base10031. The size of the entrapment area for a staple can depend on several factors such as the length of the legs, the diameter of the legs, the width of the base, and/or the extent in which the legs are deformed, for example. In previous embodiments, a surgeon was often required to select the appropriate staples having the appropriate staple height for the tissue being stapled. For example, a surgeon could select tall staples for use with thick tissue and short staples for use with thin tissue. In some circumstances, however, the tissue being stapled did not have a consistent thickness and, thus, some staples were unable to achieve the desired fired configuration. For example,FIG.48illustrates a tall staple used in thin tissue. Referring now toFIG.49, when a tissue thickness compensator, such as tissue thickness compensator10020, for example, is used with thin tissue, for example, the larger staple may be formed to a desired fired configuration. Owing to the compressibility of the tissue thickness compensator, the tissue thickness compensator can compensate for the thickness of the tissue captured within each staple. More particularly, referring now toFIGS.43and44, a tissue thickness compensator, such as tissue thickness compensator10020, for example, can consume larger and/or smaller portions of the staple entrapment area10039of each staple10030depending on the thickness and/or type of tissue contained within the staple entrapment area10039. For example, if thinner tissue T is captured within a staple10030, the tissue thickness compensator10020can consume a larger portion of the staple entrapment area10039as compared to circumstances where thicker tissue T is captured within the staple10030. Correspondingly, if thicker tissue T is captured within a staple10030, the tissue thickness compensator10020can consume a smaller portion of the staple entrapment area10039as compared to the circumstances where thinner tissue T is captured within the staple10030. In this way, the tissue thickness compensator can compensate for thinner tissue and/or thicker tissue and assure that a compressive pressure is applied to the tissue irrespective, or at least substantially irrespective, of the tissue thickness captured within the staples. In addition to the above, the tissue thickness compensator10020can compensate for different types, or compressibilities, of tissues captured within different staples10030. Referring now toFIG.44, the tissue thickness compensator10020can apply a compressive force to vascular tissue T which can include vessels V and, as a result, restrict the flow of blood through the less compressible vessels V while still applying a desired compressive pressure to the surrounding tissue T. In various circumstances, further to the above, the tissue thickness compensator10020can also compensate for malformed staples. Referring toFIG.45, the malformation of various staples10030can result in larger staple entrapment areas10039being defined within such staples. Owing to the resiliency of the tissue thickness compensator10020, referring now toFIG.46, the tissue thickness compensator10020positioned within malformed staples10030may still apply a sufficient compressive pressure to the tissue T eventhough the staple entrapment areas10039defined within such malformed staples10030may be enlarged. In various circumstances, the tissue thickness compensator10020located intermediate adjacent staples10030can be biased against the tissue T by properly-formed staples10030surrounding a malformed staple10030and, as a result, apply a compressive pressure to the tissue surrounding and/or captured within the malformed staple10030, for example. In various circumstances, a tissue thickness compensator can compensate for different tissue densities which can arise due to calcifications, fibrous areas, and/or tissue that has been previously stapled or treated, for example. In various embodiments, a fixed, or unchangeable, tissue gap can be defined between the support portion and the anvil and, as a result, the staples may be deformed to a predetermined height regardless of the thickness of the tissue captured within the staples. When a tissue thickness compensator is used with these embodiments, the tissue thickness compensator can adapt to the tissue captured between the anvil and the support portion staple cartridge and, owing to the resiliency of the tissue thickness compensator, the tissue thickness compensator can apply an additional compressive pressure to the tissue. Referring now toFIGS.50-55, a staple10030has been formed to a predefined height H. With regard toFIG.50, a tissue thickness compensator has not been utilized and the tissue T consumes the entirety of the staple entrapment area10039. With regard toFIG.57, a portion of a tissue thickness compensator10020has been captured within the staple10030, compressed the tissue T, and consumed at least a portion of the staple entrapment area10039. Referring now toFIG.52, thin tissue T has been captured within the staple10030. In this embodiment, the compressed tissue T has a height of approximately 2/9H and the compressed tissue thickness compensator10020has a height of approximately 7/9H, for example. Referring now toFIG.53, tissue T having an intermediate thickness has been captured within the staple10030. In this embodiment, the compressed tissue T has a height of approximately 4/9H and the compressed tissue thickness compensator10020has a height of approximately 5/9H, for example. Referring now toFIG.54, tissue T having an intermediate thickness has been captured within the staple10030. In this embodiment, the compressed tissue T has a height of approximately ⅔H and the compressed tissue thickness compensator10020has a height of approximately ⅓H, for example. Referring now toFIG.53, thick tissue T has been captured within the staple10030. In this embodiment, the compressed tissue T has a height of approximately 8/9H and the compressed tissue thickness compensator10020has a height of approximately 1/9H, for example. In various circumstances, the tissue thickness compensator can comprise a compressed height which comprises approximately 10% of the staple entrapment height, approximately 20% of the staple entrapment height, approximately 30% of the staple entrapment height, approximately 40% of the staple entrapment height, approximately 50% of the staple entrapment height, approximately 60% of the staple entrapment height, approximately 70% of the staple entrapment height, approximately 80% of the staple entrapment height, and/or approximately 90% of the staple entrapment height, for example. In various embodiments, the staples10030can comprise any suitable unformed height. In certain embodiments, the staples10030can comprise an unformed height between approximately 2 mm and approximately 4.8 mm, for example. The staples10030can comprise an unformed height of approximately 2.0 mm, approximately 2.5 mm, approximately 3.0 mm, approximately 3.4 mm, approximately 3.5 mm, approximately 3.8 mm, approximately 4.0 mm, approximately 4.1 mm, and/or approximately 4.8 mm, for example. In various embodiments, the height H to which the staples can be deformed can be dictated by the distance between the deck surface10011of the support portion10010and the opposing anvil. In at least one embodiment, the distance between the deck surface10011and the tissue-contacting surface of the anvil can be approximately 0.097″, for example. The height H can also be dictated by the depth of the forming pockets defined within the anvil. In at least one embodiment, the forming pockets can have a depth measured from the tissue-contacting surface, for example. In various embodiments, as described in greater detail below, the staple cartridge10000can further comprise staple drivers which can lift the staples10030toward the anvil and, in at least one embodiment, lift, or “overdrive”, the staples above the deck surface10011. In such embodiments, the height H to which the staples10030are formed can also be dictated by the distance in which the staples10030are overdriven. In at least one such embodiment, the staples10030can be overdriven by approximately 0.028″, for example, and can result in the staples10030being formed to a height of approximately 0.189″, for example. In various embodiments, the staples10030can be formed to a height of approximately 0.8 mm, approximately 1.0 mm, approximately 1.5 mm, approximately 1.8 mm, approximately 2.0 mm, and/or approximately 2.25 mm, for example. In certain embodiments, the staples can be formed to a height between approximately 2.25 mm and approximately 3.0 mm, for example. Further to the above, the height of the staple entrapment area of a staple can be determined by the formed height of the staple and the width, or diameter, of the wire comprising the staple. In various embodiments, the height of the staple entrapment area10039of a staple10030can comprise the formed height H of the staple less two diameter widths of the wire. In certain embodiments, the staple wire can comprise a diameter of approximately 0.0089″, for example. In various embodiments, the staple wire can comprise a diameter between approximately 0.0069″ and approximately 0.0119″, for example. In at least one exemplary embodiment, the formed height H of a staple10030can be approximately 0.189″ and the staple wire diameter can be approximately 0.0089″ resulting in a staple entrapment height of approximately 0.171″, for example. In various embodiments, further to the above, the tissue thickness compensator can comprise an uncompressed, or pre-deployed, height and can be configured to deform to one of a plurality of compressed heights. In certain embodiments, the tissue thickness compensator can comprise an uncompressed height of approximately 0.125″, for example. In various embodiments, the tissue thickness compensator can comprise an uncompressed height of greater than or equal to approximately 0.080″, for example. In at least one embodiment, the tissue thickness compensator can comprise an uncompressed, or pre-deployed, height which is greater than the unfired height of the staples. In at least one embodiment, the uncompressed, or pre-deployed, height of the tissue thickness compensator can be approximately 10% taller, approximately 20% taller, approximately 30% taller, approximately 40% taller, approximately 50% taller, approximately 60% taller, approximately 70% taller, approximately 80% taller, approximately 90% taller, and/or approximately 100% taller than the unfired height of the staples, for example. In at least one embodiment, the uncompressed, or pre-deployed, height of the tissue thickness compensator can be up to approximately 100% taller than the unfired height of the staples, for example. In certain embodiments, the uncompressed, or pre-deployed, height of the tissue thickness compensator can be over 100% taller than the unfired height of the staples, for example. In at least one embodiment, the tissue thickness compensator can comprise an uncompressed height which is equal to the unfired height of the staples. In at least one embodiment, the tissue thickness compensator can comprise an uncompressed height which is less than the unfired height of the staples. In at least one embodiment, the uncompressed, or pre-deployed, height of the thickness compensator can be approximately 10% shorter, approximately 20% shorter, approximately 30% shorter, approximately 40% shorter, approximately 50% shorter, approximately 60% shorter, approximately 70% shorter, approximately 80% shorter, and/or approximately 90% shorter than the unfired height of the staples, for example. In various embodiments, the compressible second portion can comprise an uncompressed height which is taller than an uncompressed height of the tissue T being stapled. In certain embodiments, the tissue thickness compensator can comprise an uncompressed height which is equal to an uncompressed height of the tissue T being stapled. In various embodiments, the tissue thickness compensator can comprise an uncompressed height which is shorter than an uncompressed height of the tissue T being stapled. As described above, a tissue thickness compensator can be compressed within a plurality of formed staples regardless of whether thick tissue or thin tissue is captured within the staples. In at least one exemplary embodiment, the staples within a staple line, or row, can be deformed such that the staple entrapment area of each staple comprises a height of approximately 2.0 mm, for example, wherein the tissue T and the tissue thickness compensator can be compressed within this height. In certain circumstances, the tissue T can comprise a compressed height of approximately 1.75 mm within the staple entrapment area while the tissue thickness compensator can comprise a compressed height of approximately 0.25 mm within the staple entrapment area, thereby totaling the approximately 2.0 mm staple entrapment area height, for example. In certain circumstances, the tissue T can comprise a compressed height of approximately 1.50 mm within the staple entrapment area while the tissue thickness compensator can comprise a compressed height of approximately 0.50 mm within the staple entrapment area, thereby totaling the approximately 2.0 mm staple entrapment area height, for example. In certain circumstances, the tissue T can comprise a compressed height of approximately 1.25 mm within the staple entrapment area while the tissue thickness compensator can comprise a compressed height of approximately 0.75 mm within the staple entrapment area, thereby totaling the approximately 2.0 mm staple entrapment area height, for example. In certain circumstances, the tissue T can comprise a compressed height of approximately 1.0 mm within the staple entrapment area while the tissue thickness compensator can comprise a compressed height of approximately 1.0 mm within the staple entrapment area, thereby totaling the approximately 2.0 mm staple entrapment area height, for example. In certain circumstances, the tissue T can comprise a compressed height of approximately 0.75 mm within the staple entrapment area while the tissue thickness compensator can comprise a compressed height of approximately 1.25 mm within the staple entrapment area, thereby totaling the approximately 2.0 mm staple entrapment area height, for example. In certain circumstances, the tissue T can comprise a compressed height of approximately 1.50 mm within the staple entrapment area while the tissue thickness compensator can comprise a compressed height of approximately 0.50 mm within the staple entrapment area, thereby totaling the approximately 2.0 mm staple entrapment area height, for example. In certain circumstances, the tissue T can comprise a compressed height of approximately 0.25 mm within the staple entrapment area while the tissue thickness compensator can comprise a compressed height of approximately 1.75 mm within the staple entrapment area, thereby totaling the approximately 2.0 mm staple entrapment area height, for example. In various embodiments, further to the above, the tissue thickness compensator can comprise an uncompressed height which is less than the fired height of the staples. In certain embodiments, the tissue thickness compensator can comprise an uncompressed height which is equal to the fired height of the staples. In certain other embodiments, the tissue thickness compensator can comprise an uncompressed height which is taller than the fired height of the staples. In at least one such embodiment, the uncompressed height of a tissue thickness compensator can comprise a thickness which is approximately 110% of the formed staple height, approximately 120% of the formed staple height, approximately 130% of the formed staple height, approximately 140% of the formed staple height, approximately 150% of the formed staple height, approximately 160% of the formed staple height, approximately 170% of the formed staple height, approximately 180% of the formed staple height, approximately 190% of the formed staple height, and/or approximately 200% of the formed staple height, for example. In certain embodiments, the tissue thickness compensator can comprise an uncompressed height which is more than twice the fired height of the staples. In various embodiments, the tissue thickness compensator can comprise a compressed height which is from approximately 85% to approximately 150% of the formed staple height, for example. In various embodiments, as described above, the tissue thickness compensator can be compressed between an uncompressed thickness and a compressed thickness. In certain embodiments, the compressed thickness of a tissue thickness compensator can be approximately 10% of its uncompressed thickness, approximately 20% of its uncompressed thickness, approximately 30% of its uncompressed thickness, approximately 40% of its uncompressed thickness, approximately 50% of its uncompressed thickness, approximately 60% of its uncompressed thickness, approximately 70% of its uncompressed thickness, approximately 80% of its uncompressed thickness, and/or approximately 90% of its uncompressed thickness, for example. In various embodiments, the uncompressed thickness of the tissue thickness compensator can be approximately two times, approximately ten times, approximately fifty times, and/or approximately one hundred times thicker than its compressed thickness, for example. In at least one embodiment, the compressed thickness of the tissue thickness compensator can be between approximately 60% and approximately 99% of its uncompressed thickness. In at least one embodiment, the uncompressed thickness of the tissue thickness compensator can be at least 50% thicker than its compressed thickness. In at least one embodiment, the uncompressed thickness of the tissue thickness compensator can be up to one hundred times thicker than its compressed thickness. In various embodiments, the compressible second portion can be elastic, or at least partially elastic, and can bias the tissue T against the deformed legs of the staples. In at least one such embodiment, the compressible second portion can resiliently expand between the tissue T and the base of the staple in order to push the tissue T against the legs of the staple. In certain embodiments, discussed in further detail below, the tissue thickness compensator can be positioned intermediate the tissue T and the deformed staple legs. In various circumstances, as a result of the above, the tissue thickness compensator can be configured to consume any gaps within the staple entrapment area. In various embodiments, the tissue thickness compensator may comprise materials characterized by one or more of the following properties: biocompatible, bioabsorable, bioresorbable, biodurable, biodegradable, compressible, fluid absorbable, swellable, self-expandable, bioactive, medicament, pharmaceutically active, anti-adhesion, haemostatic, antibiotic, anti-microbial, anti-viral, nutritional, adhesive, permeable, hydrophilic and/or hydrophobic, for example. In various embodiments, a surgical instrument comprising an anvil and a staple cartridge may comprise a tissue thickness compensator associated with the anvil and/or staple cartridge comprising at least one of a haemostatic agent, such as fibrin and thrombin, an antibiotic, such as doxycpl, and medicament, such as matrix metalloproteinases (MMPs). In various embodiments, the tissue thickness compensator may comprise synthetic and/or non-synthetic materials. The tissue thickness compensator may comprise a polymeric composition comprising one or more synthetic polymers and/or one or more non-synthetic polymers. The synthetic polymer may comprise a synthetic absorbable polymer and/or a synthetic non-absorbable polymer. In various embodiments, the polymeric composition may comprise a biocompatible foam, for example. The biocompatible foam may comprise a porous, open cell foam and/or a porous, closed cell foam, for example. The biocompatible foam may have a uniform pore morphology or may have a gradient pore morphology (i.e. small pores gradually increasing in size to large pores across the thickness of the foam in one direction). In various embodiments, the polymeric composition may comprise one or more of a porous scaffold, a porous matrix, a gel matrix, a hydrogel matrix, a solution matrix, a filamentous matrix, a tubular matrix, a composite matrix, a membranous matrix, a biostable polymer, and a biodegradable polymer, and combinations thereof. For example, the tissue thickness compensator may comprise a foam reinforced by a filamentous matrix or may comprise a foam having an additional hydrogel layer that expands in the presence of bodily fluids to further provide the compression on the tissue. In various embodiments, a tissue thickness compensator could also be comprised of a coating on a material and/or a second or third layer that expands in the presence of bodily fluids to further provide the compression on the tissue. Such a layer could be a hydrogel that could be a synthetic and/or naturally derived material and could be either biodurable and/or biodegradable, for example. In various embodiments, the tissue thickness compensator may comprise a microgel or a nanogel. The hydrogel may comprise carbohydrate-derived microgels and/or nanogels. In certain embodiments, a tissue thickness compensator may be reinforced with fibrous non-woven materials or fibrous mesh type elements, for example, that can provide additional flexibility, stiffness, and/or strength. In various embodiments, a tissue thickness compensator that has a porous morphology which exhibits a gradient structure such as, for example, small pores on one surface and larger pores on the other surface. Such morphology could be more optimal for tissue in-growth or haemostatic behavior. Further, the gradient could be also compositional with a varying bio-absorption profile. A short term absorption profile may be preferred to address hemostasis while a long term absorption profile may address better tissue healing without leakages. Examples of non-synthetic materials include, but are not limited to, lyophilized polysaccharide, glycoprotein, bovine pericardium, collagen, gelatin, fibrin, fibrinogen, elastin, proteoglycan, keratin, albumin, hydroxyethyl cellulose, cellulose, oxidized cellulose, oxidized regenerated cellulose (ORC), hydroxypropyl cellulose, carboxyethyl cellulose, carboxymethylcellulose, chitan, chitosan, casein, alginate, and combinations thereof. Examples of synthetic absorbable materials include, but are not limited to, poly(lactic acid) (PLA), poly(L-lactic acid) (PLLA), polycaprolactone (PCL), polyglycolic acid (PGA), poly(trimethylene carbonate) (TMC), polyethylene terephthalate (PET), polyhydroxyalkanoate (PHA), a copolymer of glycolide and ε-caprolactone (PGCL), a copolymer of glycolide and -trimethylene carbonate, poly(glycerol sebacate) (PGS), poly(dioxanone) (PDS), polyesters, poly(orthoesters), polyoxaesters, polyetheresters, polycarbonates, polyamide esters, polyanhydrides, polysaccharides, poly(ester-amides), tyrosine-based polyarylates, polyamines, tyrosine-based polyiminocarbonates, tyrosine-based polycarbonates, poly(D,L-lactide-urethane), poly(hydroxybutyrate), poly(B-hydroxybutyrate), poly(E-caprolactone), polyethyleneglycol (PEG), poly[bis(carboxylatophenoxy) phosphazene] poly(amino acids), pseudo-poly(amino acids), absorbable polyurethanes, poly (phosphazine), polyphosphazenes, polyalkyleneoxides, polyacrylamides, polyhydroxyethylmethylacrylate, polyvinylpyrrolidone, polyvinyl alcohols, poly(caprolactone), polyacrylic acid, polyacetate, polypropylene, aliphatic polyesters, glycerols, copoly(ether-esters), polyalkylene oxalates, polyamides, poly(iminocarbonates), polyalkylene oxalates, and combinations thereof. In various embodiments, the polyester is may be selected from the group consisting of polylactides, polyglycolides, trimethylene carbonates, polydioxanones, polycaprolactones, polybutesters, and combinations thereof. In various embodiments, the synthetic absorbable polymer may comprise one or more of 90/10 poly(glycolide-L-lactide) copolymer, commercially available from Ethicon, Inc. under the trade designation VICRYL (polyglactic 910), polyglycolide, commercially available from American Cyanamid Co. under the trade designation DEXON, polydioxanone, commercially available from Ethicon, Inc. under the trade designation PDS, poly(glycolide-trimethylene carbonate) random block copolymer, commercially available from American Cyanamid Co. under the trade designation MAXON, 75/25 poly(glycolide-ε-caprolactone-poliglecaprolactone 25) copolymer, commercially available from Ethicon under the trade designation MONOCRYL, for example. Examples of synthetic non-absorbable materials include, but are not limited to, polyurethane, polypropylene (PP), polyethylene (PE), polycarbonate, polyamides, such as nylon, polyvinylchloride (PVC), polymethylmetacrylate (PMMA), polystyrene (PS), polyester, polyetheretherketone (PEEK), polytetrafluoroethylene (PTFE), polytrifluorochloroethylene (PTFCE), polyvinylfluoride (PVF), fluorinated ethylene propylene (FEP), polyacetal, polysulfone, silicons, and combinations thereof. The synthetic non-absorbable polymers may include, but are not limited to, foamed elastomers and porous elastomers, such as, for example, silicone, polyisoprene, and rubber. In various embodiments, the synthetic polymers may comprise expanded polytetrafluoroethylene (ePTFE), commercially available from W. L. Gore & Associates, Inc. under the trade designation GORE-TEX Soft Tissue Patch and co-polyetherester urethane foam commercially available from Polyganics under the trade designation NASOPORE. In various embodiments, the polymeric composition may comprise from approximately 50% to approximately 90% by weight of the polymeric composition of PLLA and approximately 50% to approximately 10% by weight of the polymeric composition of PCL, for example. In at least one embodiment, the polymeric composition may comprise approximately 70% by weight of PLLA and approximately 30% by weight of PCL, for example. In various embodiments, the polymeric composition may comprise from approximately 55% to approximately 85% by weight of the polymeric composition of PGA and 15% to 45% by weight of the polymeric composition of PCL, for example. In at least one embodiment, the polymeric composition may comprise approximately 65% by weight of PGA and approximately 35% by weight of PCL, for example. In various embodiments, the polymeric composition may comprise from approximately 90% to approximately 95% by weight of the polymeric composition of PGA and approximately 5% to approximately 10% by weight of the polymeric composition of PLA, for example. In various embodiments, the synthetic absorbable polymer may comprise a bioabsorbable, biocompatible elastomeric copolymer. Suitable bioabsorbable, biocompatible elastomeric copolymers include but are not limited to copolymers of ε-caprolactone and glycolide (preferably having a mole ratio of ε-caprolactone to glycolide of from about 30:70 to about 70:30, preferably 35:65 to about 65:35, and more preferably 45:55 to 35:65); elastomeric copolymers of ε-caprolactone and lactide, including L-lactide, D-lactide blends thereof or lactic acid copolymers (preferably having a mole ratio of ε-caprolactone to lactide of from about 35:65 to about 65:35 and more preferably 45:55 to 30:70) elastomeric copolymers of p-dioxanone (1,4-dioxan-2-one) and lactide including L-lactide, D-lactide and lactic acid (preferably having a mole ratio of p-dioxanone to lactide of from about 40:60 to about 60:40); elastomeric copolymers of ε-caprolactone and p-dioxanone (preferably having a mole ratio of ε-caprolactone to p-dioxanone of from about 30:70 to about 70:30); elastomeric copolymers of p-dioxanone and trimethylene carbonate (preferably having a mole ratio of p-dioxanone to trimethylene carbonate of from about 30:70 to about 70:30); elastomeric copolymers of trimethylene carbonate and glycolide (preferably having a mole ratio of trimethylene carbonate to glycolide of from about 30:70 to about 70:30); elastomeric copolymer of trimethylene carbonate and lactide including L-lactide, D-lactide, blends thereof or lactic acid copolymers (preferably having a mole ratio of trimethylene carbonate to lactide of from about 30:70 to about 70:30) and blends thereof. In one embodiment, the elastomeric copolymer is a copolymer of glycolide and ε-caprolactone. In another embodiment, the elastomeric copolymer is a copolymer of lactide and ε-caprolactone. The disclosures of U.S. Pat. No. 5,468,253, entitled ELASTOMERIC MEDICAL DEVICE, which issued on Nov. 21, 1995, and U.S. Pat. No. 6,325,810, entitled FOAM BUTTRESS FOR STAPLING APPARATUS, which issued on Dec. 4, 2001, are hereby incorporated by reference in their respective entireties. In various embodiments, the tissue thickness compensator may comprise an emulsifier. Examples of emulsifiers may include, but are not limited to, water-soluble polymers, such as, polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), polyethylene glycol (PEG), polypropylene glycol (PPG), PLURONICS, TWEENS, polysaccharides and combinations thereof. In various embodiments, the tissue thickness compensator may comprise a surfactant. Examples of surfactants may include, but are not limited to, polyacrylic acid, methalose, methyl cellulose, ethyl cellulose, propyl cellulose, hydroxy ethyl cellulose, carboxy methyl cellulose, polyoxyethylene cetyl ether, polyoxyethylene lauryl ether, polyoxyethylene octyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene oleyl ether, polyoxyethylene sorbitan monolaurate, polyoxyethylene stearyl ether, polyoxyethylene nonylphenyl ether, dialkylphenoxy poly(ethyleneoxy) ethanol, and polyoxamers. In various embodiments, the polymeric composition may comprise a pharmaceutically active agent. The polymeric composition may release a therapeutically effective amount of the pharmaceutically active agent. In various embodiments, the pharmaceutically active agent may be released as the polymeric composition is desorbed/absorbed. In various embodiments, the pharmaceutically active agent may be released into fluid, such as, for example, blood, passing over or through the polymeric composition. Examples of pharmaceutically active agents may include, but are not limited to, haemostatic agents and drugs, such as, for example, fibrin, thrombin, and oxidized regenerated cellulose (ORC); anti-inflammatory drugs, such as, for example, diclofenac, aspirin, naproxen, sulindac, and hydrocortisone; antibiotic and antimicrobial drug or agents, such as, for example, triclosan, ionic silver, ampicillin, gentamicin, polymyxin B, chloramphenicol; and anticancer agents, such as, for example, cisplatin, mitomycin, adriamycin. In various embodiments, the polymeric composition may comprise a haemostatic material. The tissue thickness compensator may comprise haemostatic materials comprising poly(lactic acid), poly(glycolic acid), poly(hydroxybutyrate), poly(caprolactone), poly(dioxanone), polyalkyleneoxides, copoly(ether-esters), collagen, gelatin, thrombin, fibrin, fibrinogen, fibronectin, elastin, albumin, hemoglobin, ovalbumin, polysaccharides, hyaluronic acid, chondroitin sulfate, hydroxyethyl starch, hydroxyethyl cellulose, cellulose, oxidized cellulose, hydroxypropyl cellulose, carboxyethyl cellulose, carboxymethyl cellulose, chitan, chitosan, agarose, maltose, maltodextrin, alginate, clotting factors, methacrylate, polyurethanes, cyanoacrylates, platelet agonists, vasoconstrictors, alum, calcium, RGD peptides, proteins, protamine sulfate, ε-amino caproic acid, ferric sulfate, ferric subsulfates, ferric chloride, zinc, zinc chloride, aluminum chloride, aluminum sulfates, aluminum acetates, permanganates, tannins, bone wax, polyethylene glycols, fucans and combinations thereof. The tissue thickness compensator may be characterized by haemostatic properties. The polymeric composition of a tissue thickness compensator may be characterized by percent porosity, pore size, and/or hardness, for example. In various embodiments, the polymeric composition may have a percent porosity from approximately 30% by volume to approximately 99% by volume, for example. In certain embodiments, the polymeric composition may have a percent porosity from approximately 60% by volume to approximately 98% by volume, for example. In various embodiments, the polymeric composition may have a percent porosity from approximately 85% by volume to approximately 97% by volume, for example. In at least one embodiment, the polymeric composition may comprise approximately 70% by weight of PLLA and approximately 30% by weight of PCL, for example, and can comprise approximately 90% porosity by volume, for example. In at least one such embodiment, as a result, the polymeric composition would comprise approximately 10% copolymer by volume. In at least one embodiment, the polymeric composition may comprise approximately 65% by weight of PGA and approximately 35% by weight of PCL, for example, and can have a percent porosity from approximately 93% by volume to approximately 95% by volume, for example. In various embodiments, the polymeric composition may comprise greater than 85% porosity by volume. The polymeric composition may have a pore size from approximately 5 micrometers to approximately 2000 micrometers, for example. In various embodiments, the polymeric composition may have a pore size between approximately 10 micrometers to approximately 100 micrometers, for example. In at least one such embodiment, the polymeric composition can comprise a copolymer of PGA and PCL, for example. In certain embodiments, the polymeric composition may have a pore size between approximately 100 micrometers to approximately 1000 micrometers, for example. In at least one such embodiment, the polymeric composition can comprise a copolymer of PLLA and PCL, for example. According to certain aspects, the hardness of a polymeric composition may be expressed in terms of the Shore Hardness, which can defined as the resistance to permanent indentation of a material as determined with a durometer, such as a Shore Durometer. In order to assess the durometer value for a given material, a pressure is applied to the material with a durometer indenter foot in accordance with ASTM procedure D2240-00, entitled, “Standard Test Method for Rubber Property-Durometer Hardness”, the entirety of which is incorporated herein by reference. The durometer indenter foot may be applied to the material for a sufficient period of time, such as 15 seconds, for example, wherein a reading is then taken from the appropriate scale. Depending on the type of scale being used, a reading of 0 can be obtained when the indenter foot completely penetrates the material, and a reading of 100 can be obtained when no penetration into the material occurs. This reading is dimensionless. In various embodiments, the durometer may be determined in accordance with any suitable scale, such as Type A and/or Type OO scales, for example, in accordance with ASTM D2240-00. In various embodiments, the polymeric composition of a tissue thickness compensator may have a Shore A hardness value from approximately 4 A to approximately 16 A, for example, which is approximately 45 OO to approximately 65 OO on the Shore OO range. In at least one such embodiment, the polymeric composition can comprise a PLLA/PCL copolymer or a PGA/PCL copolymer, for example. In various embodiments, the polymeric composition of a tissue thickness compensator may have a Shore A Hardness value of less than 15 A. In various embodiments, the polymeric composition of a tissue thickness compensator may have a Shore A Hardness value of less than 10 A. In various embodiments, the polymeric composition of a tissue thickness compensator may have a Shore A Hardness value of less than 5 A. In certain embodiments, the polymeric material may have a Shore OO composition value from approximately 35 OO to approximately 75 OO, for example. In various embodiments, the polymeric composition may have at least two of the above-identified properties. In various embodiments, the polymeric composition may have at least three of the above-identified properties. The polymeric composition may have a porosity from 85% to 97% by volume, a pore size from 5 micrometers to 2000 micrometers, and a Shore A hardness value from 4 A to 16 A and Shore OO hardness value from 45 OO to 65 OO, for example. In at least one embodiment, the polymeric composition may comprise 70% by weight of the polymeric composition of PLLA and 30% by weight of the polymeric composition of PCL having a porosity of 90% by volume, a pore size from 100 micrometers to 1000 micrometers, and a Shore A hardness value from 4 A to 16 A and Shore OO hardness value from 45 OO to 65 OO, for example. In at least one embodiment, the polymeric composition may comprise 65% by weight of the polymeric composition of PGA and 35% by weight of the polymeric composition of PCL having a porosity from 93% to 95% by volume, a pore size from 10 micrometers to 100 micrometers, and a Shore A hardness value from 4 A to 16 A and Shore OO hardness value from 45 OO to 65 OO, for example. In various embodiments, the tissue thickness compensator may comprise a material that expands. As discussed above, the tissue thickness compensator may comprise a compressed material that expands when uncompressed or deployed, for example. In various embodiments, the tissue thickness compensator may comprise a self-expanding material formed in situ. In various embodiments, the tissue thickness compensator may comprise at least one precursor selected to spontaneously crosslink when contacted with at least one of other precursor(s), water, and/or bodily fluids. Referring toFIG.205, in various embodiments, a first precursor may contact one or more other precursors to form an expandable and/or swellable tissue thickness compensator. In various embodiments, the tissue thickness compensator may comprise a fluid-swellable composition, such as a water-swellable composition, for example. In various embodiments, the tissue thickness compensator may comprise a gel comprising water. Referring toFIGS.189Aand B, for example, a tissue thickness compensator70000may comprise at least one hydrogel precursor70010selected to form a hydrogel in situ and/or in vivo to expand the tissue thickness compensator70000.FIG.189Aillustrates a tissue thickness compensator70000comprising an encapsulation comprising a first hydrogel precursor70010A and a second hydrogel precursor70010B prior to expansion. In certain embodiments, as shown inFIG.189A, the first hydrogel precursor70010A and second hydrogel precursor70010B may be physically separated from other in the same encapsulation. In certain embodiments, a first encapsulation may comprise the first hydrogel precursor70010A and a second encapsulation may comprise the second hydrogel precursor70010B.FIG.189Billustrates the expansion of the thickness tissue compensator70000when the hydrogel is formed in situ and/or in vivo. As shown inFIG.189B, the encapsulation may be ruptured, and the first hydrogel precursor70010A may contact the second hydrogel precursor70010B to form the hydrogel70020. In certain embodiments, the hydrogel may comprise an expandable material. In certain embodiments, the hydrogel may expand up to 72 hours, for example. In various embodiments, the tissue thickness compensator may comprise a biodegradable foam having an encapsulation comprising dry hydrogel particles or granules embedded therein. Without wishing to be bound to any particular theory, the encapsulations in the foam may be formed by contacting an aqueous solution of a hydrogel precursor and an organic solution of biocompatible materials to form the foam. As shown inFIG.206, the aqueous solution and organic solution may form micelles. The aqueous solution and organic solution may be dried to encapsulate dry hydrogel particles or granules within the foam. For example, a hydrogel precursor, such as a hydrophilic polymer, may be dissolved in water to form a dispersion of micelles. The aqueous solution may contact an organic solution of dioxane comprising poly(glycolic acid) and polycaprolactone. The aqueous and organic solutions may be lyophilized to form a biodegradable foam having dry hydrogel particles or granules dispersed therein. Without wishing to be bound to any particular theory, it is believed that the micelles form the encapsulation having the dry hydrogel particles or granules dispersed within the foam structure. In certain embodiments, the encapsulation may be ruptured, and the dry hydrogel particles or granules may contact a fluid, such as a bodily fluid, and expand. In various embodiments, the tissue thickness compensator may expand when contacted with an activator, such as a fluid, for example. Referring toFIG.190, for example, a tissue thickness compensator70050may comprise a swellable material, such as a hydrogel, that expands when contacted with a fluid70055, such as bodily fluids, saline, water and/or an activator, for example. Examples of bodily fluids may include, but are not limited to, blood, plasma, peritoneal fluid, cerebral spinal fluid, urine, lymph fluid, synovial fluid, vitreous fluid, saliva, gastrointestinal luminal contents, bile, and/or gas (e.g., CO2). In certain embodiments, the tissue thickness compensator70050may expand when the tissue thickness compensator70050absorbs the fluid. In another example, the tissue thickness compensator70050may comprise a non-crosslinked hydrogel that expands when contacted with an activator70055comprising a cross-linking agent to form a crosslinked hydrogel. In various embodiments, the tissue thickness compensator may expand when contacted with an activator. In various embodiments, the tissue thickness compensator may expand or swell from contact up to 72 hours, such as from 24-72 hours, up to 24 hours, up to 48 hours, and up to 72 hours, for example, to provide continuously increasing pressure and/or compression to the tissue. As shown inFIG.190, the initial thickness of the tissue thickness compensator70050may be less than an expanded thickness after the fluid70055contacts the tissue thickness compensator70050. Referring toFIGS.187and188, in various embodiments, a staple cartridge70100may comprise a tissue thickness compensator70105and a plurality of staples70110each comprising staple legs70112. As shown inFIG.187, tissue thickness compensator70105may have an initial thickness or compressed height that is less than the fired height of the staples70110. The tissue thickness compensator70100may be configured to expand in situ and/or in vivo when contacted with a fluid70102, such as bodily fluids, saline, and/or an activator for example, to push the tissue T against the legs70112of the staple70110. As shown inFIG.188, the tissue thickness compensator70100may expand and/or swell when contacted with a fluid70102. The tissue thickness compensator70105can compensate for the thickness of the tissue T captured within each staple70110. As shown inFIG.188, tissue thickness compensator70105may have an expanded thickness or an uncompressed height that is less than the fired height of the staples70110. In various embodiments, as described above, the tissue thickness compensator may comprise an initial thickness and an expanded thickness. In certain embodiments, the initial thickness of a tissue thickness compensator can be approximately 0.001% of its expanded thickness, approximately 0.01% of its expanded thickness, approximately 0.1% of its expanded thickness, approximately 1% of its expanded thickness, approximately 10% of its expanded thickness, approximately 20% of its expanded thickness, approximately 30% of its expanded thickness, approximately 40% of its expanded thickness, approximately 50% of its expanded thickness, approximately 60% of its expanded thickness, approximately 70% of its expanded thickness, approximately 80% of its expanded thickness, and/or approximately 90% of its expanded thickness, for example. In various embodiments, the expanded thickness of the tissue thickness compensator can be approximately two times, approximately five times, approximately ten times, approximately fifty times, approximately one hundred times, approximately two hundred times, approximately three hundred times, approximately four hundred times, approximately five hundred times, approximately six hundred times, approximately seven hundred times, approximately eight hundred times, approximately nine hundred times, and/or approximately one thousand times thicker than its initial thickness, for example. In various embodiments, the initial thickness of the tissue thickness compensator can be up to 1% its expanded thickness, up to 5% its expanded thickness, up to 10% its expanded thickness, and up to 50% its expanded thickness. In various embodiments, the expanded thickness of the tissue thickness compensator can be at least 50% thicker than its initial thickness, at least 100% thicker than its initial thickness, at least 300% thicker than its initial thickness, and at least 500% thicker than its initial thickness. As described above, in various circumstances, as a result of the above, the tissue thickness compensator can be configured to consume any gaps within the staple entrapment area. As discussed above, in various embodiments, the tissue thickness compensator may comprise a hydrogel. In various embodiments, the hydrogel may comprise homopolymer hydrogels, copolymer hydrogels, multipolymer hydrogels, interpenetrating polymer hydrogels, and combinations thereof. In various embodiments, the hydrogel may comprise microgels, nanogels, and combinations thereof. The hydrogel may generally comprise a hydrophilic polymer network capable of absorbing and/or retaining fluids. In various embodiments, the hydrogel may comprise a non-crosslinked hydrogel, a crosslinked hydrogel, and combinations thereof. The hydrogel may comprise chemical crosslinks, physical crosslinks, hydrophobic segments and/or water insoluble segments. The hydrogel may be chemically crosslinked by polymerization, small-molecule crosslinking, and/or polymer-polymer crosslinking. The hydrogel may be physically crosslinked by ionic interactions, hydrophobic interactions, hydrogen bonding interactions, sterocomplexation, and/or supramolecular chemistry. The hydrogel may be substantially insoluble due to the crosslinks, hydrophobic segments and/or water insoluble segments, but be expandable and/or swellable due to absorbing and/or retaining fluids. In certain embodiments, the precursor may crosslink with endogenous materials and/or tissues. In various embodiments, the hydrogel may comprise an environmentally sensitive hydrogel (ESH). The ESH may comprise materials having fluid-swelling properties that relate to environmental conditions. The environmental conditions may include, but are not limited to, the physical conditions, biological conditions, and/or chemical conditions at the surgical site. In various embodiments, the hydrogel may swell or shrink in response to temperature, pH, electric fields, ionic strength, enzymatic and/or chemical reactions, electrical and/or magnetic stimuli, and other physiological and environmental variables, for example. In various embodiments, the ESH may comprise multifunctional acrylates, hydroxyethylmethacrylate (HEMA), elastomeric acrylates, and related monomers. In various embodiments, the tissue thickness compensator comprising a hydrogel may comprise at least one of the non-synthetic materials and synthetic materials described above. The hydrogel may comprise a synthetic hydrogel and/or a non-synthetic hydrogel. In various embodiments, the tissue thickness compensator may comprise a plurality of layers. The plurality of the layers may comprise porous layers and/or non-porous layers. For example, the tissue thickness compensator may comprise a non-porous layer and a porous layer. In another example, the tissue thickness compensator may comprise a porous layer intermediate a first non-porous layer and a second non-porous layer. In another example, the tissue thickness compensator may comprise a non-porous layer intermediate a first porous layer and a second porous layer. The non-porous layers and porous layers may be positioned in any order relative to the surfaces of the staple cartridge and/or anvil. Examples of the non-synthetic material may include, but are not limited to, albumin, alginate, carbohydrate, casein, cellulose, chitin, chitosan, collagen, blood, dextran, elastin, fibrin, fibrinogen, gelatin, heparin, hyaluronic acid, keratin, protein, serum, and starch. The cellulose may comprise hydroxyethyl cellulose, oxidized cellulose, oxidized regenerated cellulose (ORC), hydroxypropyl cellulose, carboxyethyl cellulose, carboxymethylcellulose, and combinations thereof. The collagen may comprise bovine pericardium. The carbohydrate may comprise a polysaccharide, such as lyophilized polysaccharide. The protein may comprise glycoprotein, proteoglycan, and combinations thereof. Examples of the synthetic material may include, but are not limited to, poly(lactic acid), poly(glycolic acid), poly(hydroxybutyrate), poly(phosphazine), polyesters, polyethylene glycols, polyethylene oxide, polyethylene oxide-co-polypropylene oxide, co-polyethylene oxide, polyalkyleneoxides, polyacrylamides, polyhydroxyethylmethylacrylate, poly(vinylpyrrolidone), polyvinyl alcohols, poly(caprolactone), poly(dioxanone), polyacrylic acid, polyacetate, polypropylene, aliphatic polyesters, glycerols, poly(amino acids), copoly(ether-esters), polyalkylene oxalates, polyamides, poly(iminocarbonates), polyoxaesters, polyorthoesters, polyphosphazenes and combinations thereof. In certain embodiments, the above non-synthetic materials may be synthetically prepared, e.g., synthetic hyaluronic acid, utilizing conventional methods. In various embodiments, the hydrogel may be made from one or more hydrogel precursors. The precursor may comprise a monomer and/or a macromer. The hydrogel precursor may comprise an electrophile functional group and/or a nucleophile electrophile functional group. In general, electrophiles may react with nucleophiles to form a bond. The term “functional group” as used herein refers to electrophilic or nucleophilic groups capable of reacting with each other to form a bond. Examples of electrophilic functional groups may include, but are not limited to, N-hydroxysuccinimides (“NETS”), sulfosuccinimides, carbonyldiimidazole, sulfonyl chloride, aryl halides, sulfosuccinimidyl esters, N-hydroxysuccinimidyl esters, succinimidyl esters such as succinimidyl succinates and/or succinimidyl propionates, isocyanates, thiocyanates, carbodiimides, benzotriazole carbonates, epoxides, aldehydes, maleimides, imidoesters, combinations thereof, and the like. In at least one embodiment, the electrophilic functional group may comprise a succinimidyl ester. Examples of nucleophile functional groups may include, but are not limited to, —NH2, —SH, —OH, —PH2, and —CO—NH—NH2. In various embodiments, the hydrogel may be formed from a single precursor or multiple precursors. In certain embodiments, the hydrogel may be formed from a first precursor and a second precursor. The first hydrogel precursor and second hydrogel precursor may form a hydrogel in situ and/or in vivo upon contact. The hydrogel precursor may generally refer to a polymer, functional group, macromolecule, small molecule, and/or crosslinker that can take part in a reaction to form a hydrogel. The precursor may comprise a homogeneous solution, heterogeneous, or phase separated solution in a suitable solvent, such as water or a buffer, for example. The buffer may have a pH from about 8 to about 12, such as, about 8.2 to about 9, for example. Examples of buffers may include, but are not limited to borate buffers. In certain embodiments, the precursor(s) may be in an emulsion. In various embodiments, a first precursor may react with a second precursor to form a hydrogel. In various embodiments, the first precursor may spontaneously crosslink when contacted with the second precursor. In various embodiments, a first set of electrophilic functional groups on a first precursor may react with a second set of nucleophilic functional groups on a second precursor. When the precursors are mixed in an environment that permits reaction (e.g., as relating to pH, temperature, and/or solvent), the functional groups may react with each other to form covalent bonds. The precursors may become crosslinked when at least some of the precursors react with more than one other precursor. In various embodiments, the tissue thickness compensator may comprise at least one monomer selected from the group consisting of 3-sulfopropyl acrylate potassium salt (“KSPA”), sodium acrylate (“NaA”), N-(tris(hydroxylmethyl)methyl)acrylamide (“tris acryl”), and 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS). The tissue thickness compensator may comprise a copolymer comprising two or more monomers selected from the group consisting of KSPA, NaA, tris acryl, AMPS. The tissue thickness compensator may comprise homopolymers derived from KSPA, NaA, trisacryl and AMPS. The tissue thickness compensator may comprise hydrophilicity modifying monomers copolymerizable therewith. The hydrophilicity modifying monomers may comprise methylmethacrylate, butylacrylate, cyclohexylacrylate, styrene, styrene sulphonic acid. In various embodiments, the tissue thickness compensator may comprise a crosslinker. The crosslinker may comprise a low molecular weight di- or polyvinylic crosslinking agent, such as ethylenglycol diacrylate or dimethacrylate, di-, tri- or tetraethylen-glycol diacrylate or dimethacrylate, allyl (meth)acrylate, a C2-C8-alkylene diacrylate or dimethacrylate, divinyl ether, divinyl sulfone, di- and trivinylbenzene, trimethylolpropane triacrylate or trimethacrylate, pentaerythritol tetraacrylate or tetramethacrylate, bisphenol A diacrylate or dimethacrylate, methylene bisacrylamide or bismethacrylamide, ethylene bisacrylamide or ethylene bismethacrylamide, triallyl phthalate or diallyl phthalate. In at least one embodiment, the crosslinker may comprise N,N′-methylenebisacrylamide (“MBAA”). In various embodiments, the tissue thickness compensator may comprise at least one of acrylate and/or methacrylate functional hydrogels, biocompatible photoinitiator, alkyl-cyanoacrylates, isocyanate functional macromers, optionally comprising amine functional macromers, succinimidyl ester functional macromers, optionally comprising amine and/or sulfhydryl functional macromers, epoxy functional macromers, optionally comprising amine functional macromers, mixtures of proteins and/or polypeptides and aldehyde crosslinkers, Genipin, and water-soluble carbodiimides, anionic polysaccharides and polyvalent cations. In various embodiments, the tissue thickness compensator may comprise unsaturated organic acid monomers, acrylic substituted alcohols, and/or acrylamides. In various embodiments, the tissue thickness compensator may comprise methacrylic acids, acrylic acids, glycerolacrylate, glycerolmethacryulate, 2-hydroxyethylmethacrylate, 2-hydroxyethylacrylate, 2-(dimethylaminoethyl) methacrylate, N-vinyl pyrrolidone, methacrylamide, and/or N, N-dimethylacrylamide poly(methacrylic acid). In various embodiments, the tissue thickness compensator may comprise a reinforcement material. In various embodiments, the reinforcement material may comprise at least one of the non-synthetic materials and synthetic materials described above. In various embodiments, the reinforcement material may comprise collagen, gelatin, fibrin, fibrinogen, elastin, keratin, albumin, hydroxyethyl cellulose, cellulose, oxidized cellulose, hydroxypropyl cellulose, carboxyethyl cellulose, carboxymethylcellulose, chitan, chitosan, alginate, poly(lactic acid), poly(glycolic acid), poly(hydroxybutyrate), poly(phosphazine), polyesters, polyethylene glycols, polyalkyleneoxides, polyacrylamides, polyhydroxyethylmethylacrylate, polyvinylpyrrolidone, polyvinyl alcohols, poly(caprolactone), poly(dioxanone), polyacrylic acid, polyacetate, polycaprolactone, polypropylene, aliphatic polyesters, glycerols, poly(amino acids), copoly(ether-esters), polyalkylene oxalates, polyamides, poly(iminocarbonates), polyalkylene oxalates, polyoxaesters, polyorthoesters, polyphosphazenes and combinations thereof. In various embodiments, the tissue thickness compensator may comprise a layer comprising the reinforcement material. In certain embodiments, a porous layer and/or a non-porous layer of a tissue thickness compensator may comprise the reinforcement material. For example, the porous layer may comprise the reinforcement material and the non-porous layer may not comprise the reinforcement material. In various embodiments, the reinforcement layer may comprise an inner layer intermediate a first non-porous layer and a second non-porous layer. In certain embodiments, the reinforcement layer may comprise an outer layer of the tissue thickness compensator. In certain embodiments, the reinforcement layer may comprise an exterior surface of the tissue thickness compensator. In various embodiments, the reinforcement material may comprise meshes, monofilaments, multifilament braids, fibers, mats, felts, particles, and/or powders. In certain embodiments, the reinforcement material may be incorporated into a layer of the tissue thickness compensator. The reinforcement material may be incorporated into at least one of a non-porous layer and a porous layer. A mesh comprising the reinforcement material may be formed using conventional techniques, such as, for example, knitting, weaving, tatting, and/or knipling. In various embodiments, a plurality of reinforcement materials may be oriented in a random direction and/or a common direction. In certain embodiments, the common direction may be one of parallel to the staple line and perpendicular to the staple line, for example. For example, the monofilaments and/or multifilament braids may be oriented in a random direction and/or a common direction. The monofilaments and multifilament braids may be associated with the non-porous layer and/or the porous layer. In various embodiments, the tissue thickness compensator may comprise a plurality of reinforcement fibers oriented in a random direction within a non-porous layer. In various embodiments, the tissue thickness compensator may comprise a plurality of reinforcement fibers oriented in a common direction within a non-porous layer. In various embodiments, referring toFIG.199, an anvil70300may comprise a tissue thickness compensator70305comprising a first non-porous layer70307and a second non-porous layer70309sealingly enclosing a reinforcement layer70310. In various embodiments, the reinforcement layer70310may comprise a hydrogel comprising ORC particles or fibers embedded therein, and the non-porous layers may comprise ORC. As shown inFIG.199, the tissue thickness compensator70305may be configured to conform to the contour of the anvil70300. The inner layer of the tissue thickness compensator70305may conform to the inner surface of the anvil70300, which includes the forming pockets70301. The fibers may form a non-woven material, such as, for example, a mat and a felt. The fibers may have any suitable length, such as, for example from 0.1 mm to 100 mm and 0.4 mm to 50 mm. The reinforcement material may be ground to a powder. The powder may have a particle size from 10 micrometers to 1 cm, for example. The powder may be incorporated into the tissue thickness compensator. In various embodiments, the tissue thickness compensator may be formed in situ. In various embodiments, the hydrogel may be formed in situ. The tissue thickness compensator may be formed in situ by covalent, ionic, and/or hydrophobic bonds. Physical (non-covalent) crosslinks may result from complexation, hydrogen bonding, desolvation, Van der Waals interactions, ionic bonding, and combinations thereof. Chemical (covalent) crosslinking may be accomplished by any of a number of mechanisms, including: free radical polymerization, condensation polymerization, anionic or cationic polymerization, step growth polymerization, electrophile-nucleophile reactions, and combinations thereof. In various embodiments, in situ formation of the tissue thickness compensator may comprise reacting two or more precursors that are physically separated until contacted in situ and/or react to an environmental condition to react with each other to form the hydrogel. In situ polymerizable polymers may be prepared from precursor(s) that can be reacted to form a polymer at the surgical site. The tissue thickness compensator may be formed by crosslinking reactions of the precursor(s) in situ. In certain embodiments, the precursor may comprise an initiator capable of initiating a polymerization reaction for the formation of the in situ tissue thickness compensator. The tissue thickness compensator may comprise a precursor that can be activated at the time of application to create, in various embodiments, a crosslinked hydrogel. In situ formation of the tissue thickness compensator may comprise activating at least one precursor to form bonds to form the tissue thickness compensator. In various embodiments, activation may be achieved by changes in the physical conditions, biological conditions, and/or chemical conditions at the surgical site, including, but not limited to temperature, pH, electric fields, ionic strength, enzymatic and/or chemical reactions, electrical and/or magnetic stimuli, and other physiological and environmental variables. In various embodiments, the precursors may be contacted outside the body and introduced to the surgical site. In various embodiments, the tissue thickness compensator may comprise one or more encapsulations, or cells, which can be configured to store at least one component therein. In certain embodiments, the encapsulation may be configured to store a hydrogel precursor therein. In certain embodiments, the encapsulation may be configured to store two components therein, for example. In certain embodiments, the encapsulation may be configured to store a first hydrogel precursor and a second hydrogel precursor therein. In certain embodiments, a first encapsulation may be configured to store a first hydrogel precursor therein and a second encapsulation may be configured to store a second hydrogel precursor therein. As described above, the encapsulations can be aligned, or at least substantially aligned, with the staple legs to puncture and/or otherwise rupture the encapsulations when the staple legs contact the encapsulation. In certain embodiments, the encapsulations may be compressed, crushed, collapsed, and/or otherwise ruptured when the staples are deployed. After the encapsulations have been ruptured, the component(s) stored therein can flow out of the encapsulation. The component stored therein may contact other components, layers of the tissue thickness compensator, and/or the tissue. In various embodiments, the other components may be flowing from the same or different encapsulations, provided in the layers of the tissue thickness compensator, and/or provided to the surgical site by the clinician. As a result of the above, the component(s) stored within the encapsulations can provide expansion and/or swelling of the tissue thickness compensator. In various embodiments, the tissue thickness compensator may comprise a layer comprising the encapsulations. In various embodiments, the encapsulation may comprise a void, a pocket, a dome, a tube, and combinations thereof associated with the layer. In certain embodiments, the encapsulations may comprise voids in the layer. In at least one embodiment, the layer can comprise two layers that can be attached to one another wherein the encapsulations can be defined between the two layers. In certain embodiments, the encapsulations may comprise domes on the surface of the layer. For example, at least a portion of the encapsulations can be positioned within domes extending upwardly from the layer. In certain embodiments, the encapsulations may comprise pockets formed within the layer. In certain embodiments, a first portion of the encapsulations may comprise a dome and a second portion of the encapsulations may comprise a pocket. In certain embodiments, the encapsulations may comprise a tube embedded within the layer. In certain embodiments, the tube may comprise the non-synthetic materials and/or synthetic materials described herein, such as PLA. In at least one embodiment, the tissue thickness compensator may comprise a bioabsorable foam, such as ORC, comprising PLA tubes embedded therein, and the tube may encapsulate a hydrogel, for example. In certain embodiments, the encapsulations may comprise discrete cells that are unconnected to each other. In certain embodiments, one or more of the encapsulations can be in fluid communication with each other via one or more passageways, conduits, and/or channels, for example, extending through the layer. The rate of release of a component from the encapsulation may be controlled by the thickness of the tissue thickness compensator, the composition of tissue thickness compensator, the size of the component, the hydrophilicity of the component, and/or the physical and/or chemical interactions among the component, the composition of the tissue thickness compensator, and/or the surgical instrument, for example. In various embodiments, the layer can comprise one or more thin sections or weakened portions, such as partial perforations, for example, which can facilitate the incision of the layer and the rupture of the encapsulations. In various embodiments, the partial perforations may not completely extend through a layer while, in certain embodiments, perforations may completely extend through the layer. Referring toFIGS.194and195, in various embodiments, a tissue thickness compensator70150may comprise an outer layer70152A and an inner layer70152B comprising encapsulations70154. In certain embodiments, the encapsulation may comprise a first encapsulated component and a second encapsulated component. In certain embodiments, the encapsulations may independently comprise one of a first encapsulated component and a second encapsulated component. The first encapsulated component may be separated from the second encapsulated component. The outer layer70152A may comprise a tissue-contacting surface. The inner layer70152B may comprise an instrument-contacting surface. The instrument-contacting surface70152B may be releasably attached to the anvil70156. The outer layer70152A may be attached to the inner layer70152B to define a void between the outer layer70152A and inner layer70152B. As shown inFIG.194, each encapsulation70154may comprise a dome on the instrument-contacting surface of the inner layer70152B. The dome may comprise partial perforations to facilitate the incision of the layer by the staple legs and the rupture of the encapsulation. As shown in theFIG.195, the anvil70156can comprise a plurality of forming pocket rows70158wherein the domes of the encapsulations70154may be aligned with the forming pocket70158. The tissue-contacting surface may comprise a flat surface lacking domes. In certain embodiments, the tissue-contacting surface may comprise one or more encapsulations, such as encapsulations70154, for example, extending therefrom. In various embodiments, an anvil may comprise a tissue thickness compensator comprising an encapsulated component comprising at least one microsphere particle. In certain embodiments, the tissue thickness compensator may comprise an encapsulation comprising a first encapsulated component and a second encapsulated component. In certain embodiments, the tissue thickness compensator may comprise an encapsulation comprising a first microsphere particle and a second microsphere particle. In various embodiments, referring toFIG.196, a stapling apparatus may comprise an anvil70180and a staple cartridge (illustrated in other figures). The staples70190of a staple cartridge can be deformed by an anvil70180when the anvil70180is moved into a closed position and/or by a staple driver system70192which moves the staples70190toward the closed anvil70180. The legs70194of the staples may contact the anvil70180such that the staples70190are at least partially deformed. The anvil70180may comprise a tissue thickness compensator70182comprising an outer layer70183A, an inner layer70183B. The tissue thickness compensator70182may comprise a first encapsulated component and a second encapsulated component. In certain embodiments, the encapsulations210185can be aligned, or at least substantially aligned, such that, when the staple legs70194are pushed through the tissue T and the outer layer70183A, the staple legs70194can puncture and/or otherwise rupture the encapsulations70185. As shown inFIG.196, the staple70190C is in its fully fired position, the staple70190B is in the process of being fired, and the staple70190A is in its unfired position. The legs of staples70190C and70190B have moved through the tissue T, the outer layer70183A, and the inner layer70183B of the tissue thickness compensator70182, and have contacted an anvil70180positioned opposite the staple cartridge. After the encapsulations70185have been ruptured, the encapsulated components can flow out and contact each other, bodily fluids, and/or the tissue T, for example. The encapsulated components may react to form a reaction product such as a hydrogel, for example, to expand between the tissue T and the base of the staple and to push the tissue T against the legs of the staple. In various circumstances, as a result of the above, the tissue thickness compensator can be configured to consume any gaps within the staple entrapment area. In various embodiments, the tissue thickness compensator may be suitable for use with a surgical instrument. As described above the tissue thickness compensator may be associated with the staple cartridge and/or the anvil. The tissue thickness compensator may be configured into any shape, size and/or dimension suitable to fit the staple cartridge and/or anvil. As described herein, the tissue thickness compensator may be releasably attached to the staple cartridge and/or anvil. The tissue thickness compensator may be attached to the staple cartridge and/or anvil in any mechanical and/or chemical manner capable of retaining the tissue thickness compensator in contact with the staple cartridge and/or anvil prior to and during the stapling process. The tissue thickness compensator may be removed or released from the staple cartridge and/or anvil after the staple penetrates the tissue thickness compensator. The tissue thickness compensator may be removed or released from the staple cartridge and/or anvil as the staple cartridge and/or anvil is moved away from the tissue thickness compensator. Referring toFIGS.191-193, stapling apparatus70118may comprise an anvil70120and a staple cartridge70122comprising a firing member70124, a plurality of staples70128, a knife edge70129, and a tissue thickness compensator70130. The tissue thickness compensator70130may comprise at least one encapsulated component. The encapsulated component may be ruptured when the tissue thickness compensator is compressed, stapled, and/or cut. Referring toFIG.192, for example, the staples70128can be deployed between an unfired position and a fired position such that the staple legs move through the tissue thickness compensator70130, penetrate through a bottom surface and a top surface of the tissue thickness compensator70130, penetrate the tissue T, and contact an anvil70120positioned opposite the staple cartridge70118. The encapsulated components may react with each other, a hydrophilic powder embedded or dispersed in the tissue thickness compensator, and/or bodily fluids to expand or swell the tissue thickness compensator70130. As the legs are deformed against the anvil, the legs of each staple can capture a portion of the tissue thickness compensator70130and a portion of the tissue T within each staple70128and apply a compressive force to the tissue T. As shown inFIGS.192and193, the tissue thickness compensator70130can compensate for the thickness of the tissue T captured within each staple70128. Referring toFIG.197, a surgical instrument70200may comprise an anvil70205comprising an upper tissue thickness compensator70210and a staple cartridge70215comprising a lower tissue thickness compensator comprising an outer layer70220and an inner layer70225. The upper tissue thickness compensator70210can be positioned on a first side of the targeted tissue and the lower tissue thickness compensator can be positioned on a second side of the tissue. In certain embodiments, the upper tissue thickness compensator70210may comprise ORC, the outer layer of the lower tissue thickness compensator may comprise a hydrogel having ORC particles embedded therein, and the inner layer of the lower tissue thickness compensator may comprise ORC, for example. Referring toFIGS.200-202, in various embodiments, a surgical instrument70400may comprise a staple cartridge70405and an anvil70410. The staple cartridge70405may comprise a tissue thickness compensator70415including bioabsorbable foam. In various embodiments, the bioabsorbable foam can comprise an encapsulation which comprises an encapsulated component70420. The bioabsorable foam may comprise ORC and the encapsulated component may comprise a medicament, for example. The tissue thickness compensator70415of the anvil70410may comprise an inner layer70425and an outer layer70430. The inner layer70425may comprise a bioabsorbable foam, and the outer layer70430may comprise a hydrogel, optionally comprising reinforcement materials, for example. During an exemplary firing sequence, referring primarily toFIG.201, a sled70435can first contact staple70440A and begin to lift the staple upwardly. As the sled70435is advanced further distally, the sled70435can begin to lift staples70440B-D, and any other subsequent staples, in a sequential order. The sled70435can drive the staples70440upwardly such that the legs of the staples contact the opposing anvil70410and are deformed to a desired shape. With regard to the firing sequence illustrated inFIG.201, the staples70440A-C have been moved into their fully fired positions, the staple70440D is in the process of being fired, and the staple70420E is still in its unfired position. The encapsulated component70470may be ruptured by the staple legs during the exemplary firing sequence. The encapsulated component70420may flow from the encapsulation around the staple legs to contact the tissue T. In various circumstances, additional compression of the tissue thickness compensator can squeeze additional medicament out of the encapsulation. In various embodiments, the medicament can immediately treat the tissue and can reduce bleeding from the tissue. In various circumstances, a surgeon, or other clinician, may deliver a fluid to the tissue thickness compensator to manufacture a tissue thickness compensator comprising at least one medicament stored and/or absorbed therein. In various embodiments, a staple cartridge and/or anvil may comprise a port configured to provide access to the tissue thickness compensator. Referring toFIG.203B, a staple cartridge70500may comprise a port70505at a distal end thereof, for example. The port70505may be configured to receive a needle70510, such as a fenestrated needle shown inFIG.203A. In at least one embodiment, the clinician may insert a needle70510through the port70505into the tissue thickness compensator70515to deliver the fluid to the tissue thickness compensator70515. In various embodiments, the fluid may comprise a medicament and hydrogel precursor, for example. As described above, the fluid may be released from tissue thickness compensator to the tissue when the tissue thickness compensator is ruptured and/or compressed. For example, the medicament may be released from the tissue thickness compensator70515as the tissue thickness compensator70515biodegrades. In various embodiments, referring now toFIG.14, a staple cartridge, such as staple cartridge10000, for example, can comprise a support portion10010and a compressible tissue thickness compensator10020. Referring now toFIGS.16-18, the support portion10010can comprise a deck surface10011and a plurality of staple cavities10012defined within the support portion10010. Each staple cavity10012can be sized and configured to removably store a staple, such as a staple10030, for example, therein. The staple cartridge10000can further comprise a plurality of staple drivers10040which can each be configured to support one or more staples10030within the staple cavities10012when the staples10030and the staple drivers10040are in their unfired positions. In at least one such embodiment, referring primarily toFIGS.22and23, each staple driver10040can comprise one or more cradles, or troughs,10041, for example, which can be configured to support the staples and limit relative movement between the staples10030and the staple drivers10040. In various embodiments, referring again toFIG.16, the staple cartridge10000can further comprise a staple-firing sled10050which can be moved from a proximal end10001to a distal end10002of the staple cartridge in order to sequentially lift the staple drivers10040and the staples10030from their unfired positions toward an anvil positioned opposite the staple cartridge10000. In certain embodiments, referring primarily toFIGS.16and18, each staple10030can comprise a base10031and one or more legs10032extending from the base10031wherein each staple can be at least one of substantially U-shaped and substantially V-shaped, for example. In at least one embodiment, the staples10030can be configured such that the tips of the staple legs10032are recessed with respect to the deck surface10011of the support portion10010when the staples10030are in their unfired positions. In at least one embodiment, the staples10030can be configured such that the tips of the staple legs10032are flush with respect to the deck surface10011of the support portion10010when the staples10030are in their unfired positions. In at least one embodiment, the staples10030can be configured such that the tips of the staple legs10032, or at least some portion of the staple legs10032, extend above the deck surface10011of the support portion10010when the staples10030are in their unfired positions. In such embodiments, the staple legs10032can extend into and can be embedded within the tissue thickness compensator10020when the staples10030are in their unfired positions. In at least one such embodiment, the staple legs10032can extend above the deck surface10011by approximately 0.075″, for example. In various embodiments, the staple legs10032can extend above the deck surface10011by a distance between approximately 0.025″ and approximately 0.125″, for example. In certain embodiments, further to the above, the tissue thickness compensator10020can comprise an uncompressed thickness between approximately 0.08″ and approximately 0.125″, for example. In use, further to the above and referring primarily toFIG.31, an anvil, such as anvil,10060, for example, can be moved into a closed position opposite the staple cartridge10000. As described in greater detail below, the anvil10060can position tissue against the tissue thickness compensator10020and, in various embodiments, compress the tissue thickness compensator10020against the deck surface10011of the support portion10010, for example. Once the anvil10060has been suitably positioned, the staples10030can be deployed, as also illustrated inFIG.31. In various embodiments, as mentioned above, the staple-firing sled10050can be moved from the proximal end10001of the staple cartridge10000toward the distal end10002, as illustrated inFIG.32. As the sled10050is advanced, the sled10050can contact the staple drivers10040and lift the staple drivers10040upwardly within the staple cavities10012. In at least one embodiment, the sled10050and the staple drivers10040can each comprise one or more ramps, or inclined surfaces, which can co-operate to move the staple drivers10040upwardly from their unfired positions. In at least one such embodiment, referring toFIGS.19-23, each staple driver10040can comprise at least one inclined surface10042and the sled10050can comprise one or more inclined surfaces10052which can be configured such that the inclined surfaces10052can slide under the inclined surface10042as the sled10050is advanced distally within the staple cartridge. As the staple drivers10040are lifted upwardly within their respective staple cavities10012, the staple drivers10040can lift the staples10030upwardly such that the staples10030can emerge from their staple cavities10012through openings in the staple deck10011. During an exemplary firing sequence, referring primarily toFIGS.25-27, the sled10050can first contact staple10030aand begin to lift the staple10030aupwardly. As the sled10050is advanced further distally, the sled10050can begin to lift staples10030b,10030c,10030d,10030e, and10030f, and any other subsequent staples, in a sequential order. As illustrated inFIG.27, the sled10050can drive the staples10030upwardly such that the legs10032of the staples contact the opposing anvil, are deformed to a desired shape, and ejected therefrom the support portion10010. In various circumstances, the sled10030can move several staples upwardly at the same time as part of a firing sequence. With regard to the firing sequence illustrated inFIG.27, the staples10030aand10030bhave been moved into their fully fired positions and ejected from the support portion10010, the staples10030cand10030dare in the process of being fired and are at least partially contained within the support portion10010, and the staples10030eand10030fare still in their unfired positions. As discussed above, and referring toFIG.33, the staple legs10032of the staples10030can extend above the deck surface10011of the support portion10010when the staples10030are in their unfired positions. With further regard to this firing sequence illustrated inFIG.27, the staples10030eand10030fare illustrated in their unfired position and their staple legs10032extend above the deck surface10011and into the tissue thickness compensator10020. In various embodiments, the tips of the staple legs10032, or any other portion of the staple legs10032, may not protrude through a top tissue-contacting surface10021of the tissue thickness compensator10020when the staples10030are in their unfired positions. As the staples10030are moved from their unfired positions to their fired positions, as illustrated inFIG.27, the tips of the staple legs can protrude through the tissue-contacting surface10032. In various embodiments, the tips of the staple legs10032can comprise sharp tips which can incise and penetrate the tissue thickness compensator10020. In certain embodiments, the tissue thickness compensator10020can comprise a plurality of apertures which can be configured to receive the staple legs10032and allow the staple legs10032to slide relative to the tissue thickness compensator10020. In certain embodiments, the support portion10010can further comprise a plurality of guides10013extending from the deck surface10011. The guides10013can be positioned adjacent to the staple cavity openings in the deck surface10011such that the staple legs10032can be at least partially supported by the guides10013. In certain embodiments, a guide10013can be positioned at a proximal end and/or a distal end of a staple cavity opening. In various embodiments, a first guide10013can be positioned at a first end of each staple cavity opening and a second guide10013can be positioned at a second end of each staple cavity opening such that each first guide10013can support a first staple leg10032of a staple10030and each second guide10013can support a second staple leg10032of the staple. In at least one embodiment, referring toFIG.33, each guide10013can comprise a groove or slot, such as groove10016, for example, within which a staple leg10032can be slidably received. In various embodiments, each guide10013can comprise a cleat, protrusion, and/or spike that can extend from the deck surface10011and can extend into the tissue thickness compensator10020. In at least one embodiment, as discussed in greater detail below, the cleats, protrusions, and/or spikes can reduce relative movement between the tissue thickness compensator10020and the support portion10010. In certain embodiments, the tips of the staple legs10032may be positioned within the guides10013and may not extend above the top surfaces of the guides10013when the staples10030are in their unfired position. In at least such embodiment, the guides10013can define a guide height and the staples10030may not extend above this guide height when they are in their unfired position. In various embodiments, a tissue thickness compensator, such as tissue thickness compensator10020, for example, can be comprised of a single sheet of material. In at least one embodiment, a tissue thickness compensator can comprise a continuous sheet of material which can cover the entire top deck surface10011of the support portion10010or, alternatively, cover less than the entire deck surface10011. In certain embodiments, the sheet of material can cover the staple cavity openings in the support portion10010while, in other embodiments, the sheet of material can comprise openings which can be aligned, or at least partially aligned, with the staple cavity openings. In various embodiments, a tissue thickness compensator can be comprised of multiple layers of material. In some embodiments, referring now toFIG.15, a tissue thickness compensator can comprise a compressible core and a wrap surrounding the compressible core. In certain embodiments, a wrap10022can be configured to releasably hold the compressible core to the support portion10010. In at least one such embodiment, the support portion10010can comprise one or more projections, such as projections10014(FIG.18), for example, extending therefrom which can be received within one or more apertures and/or slots, such as apertures10024, for example, defined in the wrap10022. The projections10014and the apertures10024can be configured such that the projections10014can retain the wrap10022to the support portion10010. In at least one embodiment, the ends of the projections10014can be deformed, such as by a heat-stake process, for example, in order to enlarge the ends of the projections10014and, as a result, limit the relative movement between the wrap10022and the support portion10010. In at least one embodiment, the wrap10022can comprise one or more perforations10025which can facilitate the release of the wrap10022from the support portion10010, as illustrated inFIG.15. Referring now toFIG.24, a tissue thickness compensator can comprise a wrap10222including a plurality of apertures10223, wherein the apertures10223can be aligned, or at least partially aligned, with the staple cavity openings in the support portion10010. In certain embodiments, the core of the tissue thickness compensator can also comprise apertures which are aligned, or at least partially aligned, with the apertures10223in the wrap10222. In other embodiments, the core of the tissue thickness compensator can comprise a continuous body and can extend underneath the apertures10223such that the continuous body covers the staple cavity openings in the deck surface10011. In various embodiments, as described above, a tissue thickness compensator can comprise a wrap for releasably holding a compressible core to the support portion10010. In at least one such embodiment, referring toFIG.16, a staple cartridge can further comprise retainer clips10026which can be configured to inhibit the wrap, and the compressible core, from prematurely detaching from the support portion10010. In various embodiments, each retainer clip10026can comprise apertures10028which can be configured to receive the projections10014extending from the support portion10010such that the retainer clips10026can be retained to the support portion10010. In certain embodiments, the retainer clips10026can each comprise at least one pan portion10027which can extend underneath the support portion10010and can support and retain the staple drivers10040within the support portion10010. In certain embodiments, as described above, a tissue thickness compensator can be removably attached to the support portion10010by the staples10030. More particularly, as also described above, the legs of the staples10030can extend into the tissue thickness compensator10020when the staples10030are in their unfired position and, as a result, releasably hold the tissue thickness compensator10020to the support portion10010. In at least one embodiment, the legs of the staples10030can be in contact with the sidewalls of their respective staple cavities10012wherein, owing to friction between the staple legs10032and the sidewalls, the staples10030and the tissue thickness compensator10020can be retained in position until the staples10030are deployed from the staple cartridge10000. When the staples10030are deployed, the tissue thickness compensator10020can be captured within the staples10030and held against the stapled tissue T. When the anvil is thereafter moved into an open position to release the tissue T, the support portion10010can be moved away from the tissue thickness compensator10020which has been fastened to the tissue. In certain embodiments, an adhesive can be utilized to removably hold the tissue thickness compensator10020to the support portion10010. In at least one embodiment, a two-part adhesive can be utilized wherein, in at least one embodiment, a first part of the adhesive can be placed on the deck surface10011and a second part of the adhesive can be placed on the tissue thickness compensator10020such that, when the tissue thickness compensator10020is placed against the deck surface10011, the first part can contact the second part to active the adhesive and detachably bond the tissue thickness compensator10020to the support portion10010. In various embodiments, any other suitable means could be used to detachably retain the tissue thickness compensator to the support portion of a staple cartridge. In various embodiments, further to the above, the sled10050can be advanced from the proximal end10001to the distal end10002to fully deploy all of the staples10030contained within the staple cartridge10000. In at least one embodiment, referring now toFIGS.56-60, the sled10050can be advanced distally within a longitudinal cavity10016within the support portion10010by a firing member, or knife bar,10052of a surgical stapler. In use, the staple cartridge10000can be inserted into a staple cartridge channel in a jaw of the surgical stapler, such as staple cartridge channel10070, for example, and the firing member10052can be advanced into contact with the sled10050, as illustrated inFIG.56. As the sled10050is advanced distally by the firing member10052, the sled10050can contact the proximal-most staple driver, or drivers,10040and fire, or eject, the staples10030from the cartridge body10010, as described above. As illustrated inFIG.56, the firing member10052can further comprise a cutting edge10053which can be advanced distally through a knife slot in the support portion10010as the staples10030are being fired. In various embodiments, a corresponding knife slot can extend through the anvil positioned opposite the staple cartridge10000such that, in at least one embodiment, the cutting edge10053can extend between the anvil and the support portion10010and incise the tissue and the tissue thickness compensator positioned therebetween. In various circumstances, the sled10050can be advanced distally by the firing member10052until the sled10050reaches the distal end10002of the staple cartridge10000, as illustrated inFIG.58. At such point, the firing member10052can be retracted proximally. In some embodiments, the sled10050can be retracted proximally with the firing member10052but, in various embodiments, referring now toFIG.59, the sled10050can be left behind in the distal end10002of the staple cartridge10000when the firing member10052is retracted. Once the firing member10052has been sufficiently retracted, the anvil can be re-opened, the tissue thickness compensator10020can be detached from the support portion10010, and the remaining non-implanted portion of the expended staple cartridge10000, including the support portion10010, can be removed from the staple cartridge channel10070. After the expended staple cartridge10000has been removed from the staple cartridge channel, further to the above, a new staple cartridge10000, or any other suitable staple cartridge, can be inserted into the staple cartridge channel10070. In various embodiments, further to the above, the staple cartridge channel10070, the firing member10052, and/or the staple cartridge10000can comprise co-operating features which can prevent the firing member10052from being advanced distally a second, or subsequent, time without a new, or unfired, staple cartridge10000positioned in the staple cartridge channel10070. More particularly, referring again toFIG.56, as the firing member10052is advanced into contact with the sled10050and, when the sled10050is in its proximal unfired position, a support nose10055of the firing member10052can be positioned on and/or over a support ledge10056on the sled10050such that the firing member10052is held in a sufficient upward position to prevent a lock, or beam,10054extending from the firing member10052from dropping into a lock recess defined within the staple cartridge channel. As the lock10054will not drop into the lock recess, in such circumstances, the lock10054may not abut a distal sidewall10057of the lock recess as the firing member10052is advanced. As the firing member10052pushes the sled10050distally, the firing member10052can be supported in its upward firing position owing to the support nose10055resting on the support ledge10056. When the firing member10052is retracted relative to the sled10050, as discussed above and illustrated inFIG.59, the firing member10052can drop downwardly from its upward position as the support nose10055is no longer resting on the support ledge10056of the sled10050. In at least one such embodiment, the surgical staple can comprise a spring10058, and/or any other suitable biasing element, which can be configured to bias the firing member10052into its downward position. Once the firing member10052has been completely retracted, as illustrated inFIG.60, the firing member10052cannot be advanced distally through the spent staple cartridge10000once again. More particularly, the firing member10052can't be held in its upper position by the sled10050as the sled10050, at this point in the operating sequence, has been left behind at the distal end10002of the staple cartridge10000. Thus, as mentioned above, in the event that the firing member10052is advanced once again without replacing the staple cartridge, the lock beam10054will contact the sidewall10057of the lock recess which will prevent the firing member10052from being advanced distally into the staple cartridge10000once again. Stated another way, once the spent staple cartridge10000has been replaced with a new staple cartridge, the new staple cartridge will have a proximally-positioned sled10050which can hold the firing member10052in its upper position and allow the firing member10052to be advanced distally once again. As described above, the sled10050can be configured to move the staple drivers10040between a first, unfired position and a second, fired position in order to eject staples10030from the support portion10010. In various embodiments, the staple drivers10040can be contained within the staple cavities10012after the staples10030have been ejected from the support portion10010. In certain embodiments, the support portion10010can comprise one or more retention features which can be configured to block the staple drivers10040from being ejected from, or falling out of, the staple cavities10012. In various other embodiments, the sled10050can be configured to eject the staple drivers10040from the support portion10010with the staples10030. In at least one such embodiment, the staple drivers10040can be comprised of a bioabsorbable and/or biocompatible material, such as Ultem, for example. In certain embodiments, the staple drivers can be attached to the staples10030. In at least one such embodiment, a staple driver can be molded over and/or around the base of each staple10030such that the driver is integrally formed with the staple. U.S. patent application Ser. No. 11/541,123, entitled SURGICAL STAPLES HAVING COMPRESSIBLE OR CRUSHABLE MEMBERS FOR SECURING TISSUE THEREIN AND STAPLING INSTRUMENTS FOR DEPLOYING THE SAME, filed on Sep. 29, 2006, is hereby incorporated by reference in its entirety. As described above, a surgical stapling instrument can comprise a staple cartridge channel configured to receive a staple cartridge, an anvil rotatably coupled to the staple cartridge channel, and a firing member comprising a knife edge which is movable relative to the anvil and the staple cartridge channel. In use, a staple cartridge can be positioned within the staple cartridge channel and, after the staple cartridge has been at least partially expended, the staple cartridge can be removed from the staple cartridge channel and replaced with a new staple cartridge. In some such embodiments, the staple cartridge channel, the anvil, and/or the firing member of the surgical stapling instrument may be re-used with the replacement staple cartridge. In certain other embodiments, a staple cartridge may comprise a part of a disposable loading unit assembly which can include a staple cartridge channel, an anvil, and/or a firing member, for example, which can be replaced along with the staple cartridge as part of replacing the disposable loading unit assembly. Certain disposable loading unit assemblies are disclosed in U.S. patent application Ser. No. 12/031,817, entitled END EFFECTOR COUPLING ARRANGEMENTS FOR A SURGICAL CUTTING AND STAPLING INSTRUMENT, now U.S. Patent Application Publication No. 2009/0206131, which was filed on Feb. 15, 2008, the entire disclosure of which is incorporated by reference herein. In various embodiments, the tissue thickness compensator may comprise an extrudable, a castable, and/or moldable composition comprising at least one of the synthetic and/or non-synthetic materials described herein. In various embodiments, the tissue thickness compensator may comprise a film or sheet comprising two or more layers. The tissue thickness compensator may be obtained using conventional methods, such as, for example, mixing, blending, compounding, spraying, wicking, solvent evaporating, dipping, brushing, vapor deposition, extruding, calendaring, casting, molding and the like. In extrusion, an opening may be in the form of a die comprising at least one opening to impart a shape to the emerging extrudate. In calendering, an opening may comprise a nip between two rolls. Conventional molding methods may include, but are not limited to, blow molding, injection molding, foam injection, compression molding, thermoforming, extrusion, foam extrusion, film blowing, calendaring, spinning, solvent welding, coating methods, such as dip coating and spin coating, solution casting and film casting, plastisol processing (including knife coating, roller coating and casting), and combinations thereof. In injection molding, an opening may comprise a nozzle and/or channels/runners and/or mold cavities and features. In compression molding, the composition may be positioned in a mold cavity, heated to a suitable temperature, and shaped by exposure to compression under relatively high pressure. In casting, the composition may comprise a liquid or slurry that may be poured or otherwise provided into, onto and/or around a mold or object to replicate features of the mold or object. After casting, the composition may be dried, cooled, and/or cured to form a solid. In various embodiments, a method of manufacturing a tissue thickness compensator may generally comprise providing a tissue thickness compensator composition, liquifying the composition to make it flowable, and forming the composition in the molten, semi-molten, or plastic state into a layer and/or film having the desired thickness. Referring toFIG.198A, a tissue thickness compensator may be manufactured by dissolving a hydrogel precursor in an aqueous solution, dispersing biocompatible particles and/or fibers therein, providing a mold having biocompatible particles therein, providing the solution into the mold, contacting an activator and the solution, and curing the solution to form the tissue thickness compensator comprising an outer layer comprise biocompatible particles and an inner layer comprising biocompatible particles embedded therein. A shown inFIG.198A, a biocompatible layer70250may be provided in the bottom of a mold70260, and an aqueous solution of a hydrogel precursor70255having biocompatible particles70257disposed therein may be provided to the mold70260, and the aqueous solution may be cured to form a tissue thickness compensator having a first layer comprising a biocompatible material, such as ORC, for example, and a second layer comprising a hydrogel having biocompatible fibers, such as ORC fibers, disposed therein. The tissue thickness compensator may comprise a foam comprising an outer layer comprise biocompatible particles and an inner layer comprising biocompatible particles embedded therein. In at least one embodiment, a tissue thickness compensator may be manufactured by dissolving a sodium alginater in water, dispersing ORC particles therein, providing a mold having ORC particles therein, pouring the solution into the mold, spraying or infusing calcium chloride to contact the solution to initiate crosslinking of the sodium alginater, freeze drying the hydrogel to form the tissue thickness compensator comprising an outer layer comprising ORC and an inner layer comprising a hydrogel and ORC particles embedded therein. Referring toFIG.198B, in various embodiments, a method of manufacturing a trilayer tissue thickness compensator may generally comprise by dissolving a first hydrogel precursor in a first aqueous solution, dispersing biocompatible particles and/or fibers in the first aqueous solution, providing a mold70260having a first layer70250of biocompatible particles therein, providing the first aqueous solution into the mold, contacting an activator and the first aqueous solution, curing the first aqueous solution to form a second layer70255, dissolving a second hydrogel precursor in a second aqueous solution, providing the second aqueous solution into the mold, curing the second aqueous solution to form a third layer70265. In at least one embodiment, a trilayer tissue thickness compensator may be manufactured by dissolving a sodium alginater in water to form a first aqueous solution, dispersing ORC particles in the first aqueous solution, providing a mold having a first layer of ORC particles therein, pouring the first aqueous solution into the mold, spraying or infusing calcium chloride to contact the first aqueous solution to initiate crosslinking of the sodium alginater, freeze drying the first aqueous solution to form a second layer comprising a hydrogel having ORC particles embedded therein, dissolving a sodium alginater in water to form a second aqueous solution, pouring the second aqueous solution into the mold, spraying or infusing calcium chloride to contact the second aqueous solution to initiate crosslinking of the sodium alginater, freeze drying the second aqueous solution to form a third layer comprising a hydrogel. In various embodiments, a method of manufacturing a tissue thickness compensator comprising at least one medicament stored and/or absorbed therein may generally comprise providing a tissue thickness compensator and contacting the tissue thickness compensator and the medicament to retain the medicament in the tissue thickness compensator. In at least one embodiment, a method of manufacturing a tissue thickness compensator comprising an antibacterial material may comprise providing a hydrogel, drying the hydrogel, swelling the hydrogel in an aqueous solution of silver nitrate, contacting the hydrogel and a solution of sodium chloride to form the tissue thickness compensator having antibacterial properties. The tissue thickness compensator may comprise silver dispersed therein. Referring toFIG.204, in various embodiments, a method for manufacturing a tissue thickness compensator may comprise co-extrusion and/or bonding. In various embodiments, the tissue thickness compensator70550may comprise a laminate comprising a first layer70555and a second layer70560sealingly enclosing an inner layer70565comprising a hydrogel, for example. The hydrogel may comprise a dry film, a dry foam, a powder, and/or granules, for example. The hydrogel may comprise super absorbent materials, such as, for example, polyvinylpyrrolidone, carboxy methycellulose, poly sulful propyl acrylate. The first and/or second layers may be made in-line by feeding raw materials of the first and second layers, respectively, into an extruder from a hopper, and thereafter supplying the first and second layers. The raw materials of the inner layer70565may be added to a hopper of an extruder. The raw materials can be dispersively mixed and compounded at an elevated temperature within the extruder. As the raw materials exit the die70570at an opening, the inner layer70565may be deposited onto a surface of the first layer70555. In various embodiments, the tissue thickness compensator may comprise a foam, film, powder, and/or granule. The first and second layers70555and70560may be positioned in the face-to-face relationship. The second layer70560may be aligned with the first layer70555in a face-to-face relationship by a roller70575. The first layer70555may adhere to the second layer70560wherein the first and second layers70555,70560may physically entrap the inner layer70565. The layers may be joined together under light pressure, under conventional calendar bonding processes, and/or through the use of adhesives, for example, to form the tissue thickness compensator70550. In at least one embodiment, as shown inFIG.78, the first and second layers70555and70560may be joined together through a rolling process utilizing a grooved roller70580, for example. In various embodiments, as a result of the above, the inner layer70565may be contained and/or sealed by the first and second layers70555and70560which can collectively form an outer layer, or barrier. The outer layer may prevent or reduce moisture from contacting the inner layer70565until the outer layer is ruptured. Referring toFIG.61, an end effector12for a surgical instrument10(FIG.1) can be configured to receive a fastener cartridge assembly, such as staple cartridge20000, for example. As illustrated inFIG.61, the staple cartridge20000can be configured to fit in a cartridge channel20072of a jaw20070of the end effector12. In other embodiments, the staple cartridge20000can be integral to the end effector12such that the staple cartridge20000and the end effector12are formed as a single unit construction. The staple cartridge20000can comprise a first body portion, such as rigid support portion20010, for example. The staple cartridge20000can also comprise a second body portion, such as a compressible portion or a tissue thickness compensator20020, for example. In other embodiments, the tissue thickness compensator20020may not comprise an integral part of the staple cartridge20000but may be otherwise positioned relative to the end effector12. For example, the tissue thickness compensator20020can be secured to an anvil20060of the end effector12or can be otherwise retained in the end effector12. In at least one embodiment, referring toFIG.78, the staple cartridge can further comprise retainer clips20126which can be configured to inhibit the tissue thickness compensator20020from prematurely detaching from the support portion20010. The reader will appreciate that the tissue thickness compensators described herein can be installed in or otherwise engaged with a variety of end effectors and that such embodiments are within the scope of the present disclosure. Similar to the tissue thickness compensators described herein, referring now toFIG.78, the tissue thickness compensator20020can be released from or disengaged with the surgical end effector12. For example, in some embodiments, the rigid support portion20010of the staple cartridge20000can remain engaged with the fastener cartridge channel20072of the end effector jaw20070while the tissue thickness compensator20020disengages from the rigid support portion20010. In various embodiments, the tissue thickness compensator20020can release from the end effector12after staples20030(FIGS.78-83) are deployed from staple cavities20012in the rigid support portion2010, similar to various embodiments described herein. Staples20030can be fired from staple cavities20012such that the staples20030engage the tissue thickness compensator20020. Also similar to various embodiments described herein, referring generally toFIGS.63,82and83, a staple20030can capture a portion of the tissue thickness compensator20020along with stapled tissue T. In some embodiments, the tissue thickness compensator20020can be deformable and the portion of the tissue thickness compensator20020that is captured within a fired staple20030can be compressed. Similar to the tissue thickness compensators described herein, the tissue thickness compensator20020can compensate for different thicknesses, compressibilities, and/or densities of tissue T captured within each staple20030. Further, as also described herein, the tissue thickness compensator20020can compensate for gaps created by malformed staples20030. The tissue thickness compensator20020can be compressible between non-compressed height(s) and compressed height(s). Referring toFIG.78, the tissue thickness compensator20020can have a top surface20021and a bottom surface20022. The height of the tissue thickness compensator can be the distance between the top surface20021and the bottom surface20022. In various embodiments, the non-compressed height of the tissue thickness compensator20020can be the distance between the top surface20021and the bottom surface20022when minimal or no force is applied to the tissue thickness compensator20020, i.e., when the tissue thickness compensator20020is not compressed. The compressed height of the tissue thickness compensator20020can be the distance between the top surface20021and the bottom surface20022when a force is applied to the tissue thickness compensator20020, such as when a fired staple20030captures a portion of the tissue thickness compensator20020, for example. The tissue thickness compensator20020can have a distal end20025and a proximal end20026. As illustrated inFIG.78, the non-compressed height of the tissue thickness compensator20020can be uniform between the distal end20025and the proximal end20026of the tissue thickness compensator20020. In other embodiments, the non-compressed height can vary between the distal end20025and the proximal end20026. For example, the top surface20021and/or bottom surface20022of the tissue thickness compensator20020can be angled and/or stepped relative to the other such that the non-compressed height varies between the proximal end20026and the distal end20025. In some embodiments, the non-compressed height of the tissue thickness compensator20020can be approximately 0.08 inches, for example. In other embodiments, the non-compressed height of the tissue thickness compensator20020can vary between approximately 0.025 inches and approximately 0.10 inches, for example. As described in greater detail herein, the tissue thickness compensator20020can be compressed to different compressed heights between the proximal end20026and the distal end20025thereof. In other embodiments, the tissue thickness compensator20020can be uniformly compressed throughout the length thereof. The compressed height(s) of the tissue thickness compensator20020can depend on the geometry of the end effector12, characteristics of the tissue thickness compensator20020, the engaged tissue T and/or the staples20030, for example. In various embodiments, the compressed height of the tissue thickness compensator20020can relate to the tissue gap in the end effector12. In various embodiments, when the anvil20060is clamped towards the staple cartridge20000, the tissue gap can be defined between a top deck surface20011(FIG.78) of the staple cartridge20000and a tissue contacting surface20061(FIG.61) of the anvil20060, for example. The tissue gap can be approximately 0.025 inches or approximately 0.100 inches, for example. In some embodiments, the tissue gap can be approximately 0.750 millimeters or approximately 3.500 millimeters, for example. In various embodiments, the compressed height of the tissue thickness compensator20020can equal or substantially equal the tissue gap, for example. When tissue T is positioned within the tissue gap of the end effector12, the compressed height of the tissue thickness compensator can be less in order to accommodate the tissue T. For example, where the tissue gap is approximately 0.750 millimeters, the compressed height of the tissue thickness compensator can be approximately 0.500 millimeters. In embodiments where the tissue gap is approximately 3.500 millimeters, the compressed height of the tissue thickness compensator20020can be approximately 2.5 mm, for example. Furthermore, the tissue thickness compensator20020can comprise a minimum compressed height. For example, the minimum compressed height of the tissue thickness compensator20020can be approximately 0.250 millimeters. In various embodiments, the tissue gap defined between the deck surface of the staple cartridge and the tissue contacting surface of the anvil can equal, or at least substantially equal, the uncompressed height of the tissue thickness compensator, for example. Referring primarily toFIG.62, the tissue thickness compensator20020can comprise a fibrous, nonwoven material20080including fibers20082. In some embodiments, the tissue thickness compensator20020can comprise felt or a felt-like material. Fibers20082in the nonwoven material20080can be fastened together by any means known in the art, including, but not limited to, needle-punching, thermal bonding, hydro-entanglement, ultrasonic pattern bonding, chemical bonding, and meltblown bonding. Further, in various embodiments, layers of nonwoven material20080can be mechanically, thermally, or chemically fastened together to form the tissue thickness compensator20020. As described in greater detail herein, the fibrous, nonwoven material20080can be compressible, which can enable compression of the tissue thickness compensator20020. In various embodiments, the tissue thickness compensator20020can comprise a non-compressible portion as well. For example, the tissue thickness compensator20020can comprise a compressible nonwoven material20080and a non-compressible portion. Still referring primarily toFIG.62, the nonwoven material20080can comprise a plurality of fibers20082. At least some of the fibers20082in the nonwoven material20080can be crimped fibers20086. The crimped fibers20086can be, for example, crimped, twisted, coiled, bent, crippled, spiraled, curled, and/or bowed within the nonwoven material20080. As described in greater detail herein, the crimped fibers20086can be formed in any suitable shape such that deformation of the crimped fibers20086generates a spring load or restoring force. In some embodiments, the crimped fibers20086can be heat-shaped to form a coiled or substantially coil-like shape. The crimped fibers20086can be formed from non-crimped fibers20084. For example, non-crimped fibers20084can be wound around a heated mandrel to form a substantially coil-like shape. In various embodiments, the tissue thickness compensator20020can comprise a homogeneous absorbable polymer matrix. The homogenous absorbable polymer matrix can comprise a foam, gel, and/or film, for example. Further, the plurality of fibers20082can be dispersed throughout the homogenous absorbable polymer matrix. At least some of the fibers20082in the homogenous absorbable polymer matrix can be crimped fibers20086, for example. As described in greater detail herein, the homogeneous absorbable polymer matrix of the tissue thickness compensator2002can be compressible. In various embodiments, referring toFIGS.65and66, crimped fibers20086can be randomly dispersed throughout at least a portion of the nonwoven material20080. For example, crimped fibers20086can be randomly dispersed throughout the nonwoven material20080such that a portion of the nonwoven material20080comprises more crimped fibers20086than other portions of the nonwoven material20080. Further, the crimped fibers20086can congregate in fiber clusters20085a,20085b,20085c,20085dand20085e, for example, in the nonwoven material20080. The shape of the crimped fibers20086can cause entanglement of the fibers20086during manufacturing of the nonwoven material20080; entanglement of the crimped fibers20086can, in turn, result in the formation of the fiber clusters20085a,20085b,20085c,20085dand20085e. Additionally or alternatively, crimped fibers20086can be randomly oriented throughout the nonwoven material20080. For example, referring toFIG.62, a first crimped fiber20086acan be oriented in a first direction, a second crimped fiber20086bcan be oriented in a second direction, and a third crimped fiber20086ccan be oriented in a third direction. In some embodiments, the crimped fibers20086can be systematically distributed and/or arranged throughout at least a portion of the nonwoven material20080. For example, referring now toFIG.67, crimped fibers20186can be positioned in an arrangement20185, in which a plurality of crimped fibers20186aare arranged in a first direction and another plurality of crimped fibers20186bare arranged in a second direction. The crimped fibers20186can overlap such that they become entangled or interconnected with each other. In various embodiments, the crimped fibers20186can be systematically arranged such that a crimped fiber20186ais substantially parallel to another crimped fiber20186a. Still another crimped fiber20186bcan be substantially transverse to some crimped fibers20186a. In various embodiments, crimped fibers20186acan be substantially aligned with a first axis Y and crimped fibers20186bcan be substantially aligned with a second axis X. In some embodiments the first axis Y can be perpendicular or substantially perpendicular to the second axis X, for example. Referring primarily toFIG.68, in various embodiments, crimped fibers20286can be arranged in an arrangement20285. In some embodiments, each crimped fibers20286can comprise a longitudinal axis defined between a first end20287and a second end20289of the crimped fiber20286. In some embodiments, the crimped fibers20286can be systematically distributed in the nonwoven material20080such that a first end20287of one crimped fiber20286is positioned adjacent to a second end20289of another crimped fiber20286. In another embodiment, referring now toFIG.69, a fiber arrangement20385can comprise a first crimped fiber20386aoriented in a first direction, a second crimped fiber20386boriented in a second direction, and a third crimped fiber20386coriented in a third direction, for example. In various embodiments, a single pattern or arrangement of crimped fibers20286can be repeated throughout the nonwoven material20080. In at least one embodiment, crimped fibers can be arranged in different patterns throughout the nonwoven material20080. In still other embodiments, the nonwoven material20080can comprise at least one pattern of crimped fibers, as well as a plurality of randomly oriented and/or randomly distributed crimped fibers. Referring again toFIG.62, the plurality of fibers20082in the nonwoven material20080can comprise at least some non-crimped fibers20084. The non-crimped fibers20084and crimped fibers20086in the nonwoven material20080can be entangled or interconnected. In one embodiment, the ratio of crimped fibers20086to non-crimped fibers20084can be approximately 25:1, for example. In another embodiment, the ratio of crimped fibers20086to non-crimped fibers20084can be approximately 1:25, for example. In other embodiments, the ratio of crimped fibers20086to non-crimped fibers20084can be approximately 1:1, for example. As described in greater detail herein, the number of crimped fibers20086per unit volume of nonwoven material20080can affect the restoring force generated by the nonwoven material20080when the nonwoven material20080has been deformed. As also described in greater detail herein, the restoring force generated by the nonwoven material20080can also depend on, for example, the material, shape, size, position and/or orientation of crimped and non-crimped fibers20086,20084in the nonwoven material20080. In various embodiments, the fibers20082of the nonwoven material20080can comprise a polymeric composition. The polymeric composition of the fibers20082can comprise non-absorbable polymers, absorbable polymers, or combinations thereof. In some embodiments, the absorbable polymers can include bioabsorbable, biocompatible elastomeric polymers. Furthermore, the polymeric composition of the fibers20082can comprise synthetic polymers, non-synthetic polymers, or combinations thereof. Examples of synthetic polymers include, but are not limited to, polyglycolic acid (PGA), poly(lactic acid) (PLA), polycaprolactone (PCL), polydioxanone (PDO), and copolymers thereof. For example, the fibers20082can comprise a 90/10 poly(glycolide-L-lactide) copolymer, such as, for example, the copolymer commercially available from Ethicon, Inc. under the trade designation “VICRYL (polyglactic 910).” Examples of non-synthetic polymers include, but are not limited to, lyophilized polysaccharide, glycoprotein, elastin, proteoglycan, gelatin, collagen, and oxidized regenerated cellulose (ORC). In various embodiments, similar to the polymeric compositions in tissue thickness compensators described herein, the polymeric composition of the fibers20082can include varied amounts of absorbable polymers, non-absorbable polymers, synthetic polymers, and/or non-synthetic polymers, for example, by weight percentage. In some embodiments, the crimped fibers20086of the nonwoven material20080can comprise a first polymeric composition and the non-crimped fibers20084of the nonwoven material20080can comprise a different polymeric composition. For example, the crimped fibers20086can comprise synthetic polymer(s), such as, for example, 90/10 poly(glycolide-L-lactide), while the non-crimped fibers20084can comprise non-synthetic polymer(s), such as, for example, oxidized regenerated cellulose. In other embodiments, the crimped fibers20086and the non-crimped fibers20084can comprise the same polymeric composition. As described herein, crimped fibers20086and non-crimped fibers20084can be fastened together, for example, by needle-punching, thermal bonding, hydro-entanglement, ultrasonic pattern bonding, chemical bonding, and meltblown bonding. In some embodiments, crimped fibers20086comprising synthetic polymers such as, for example, “VICRYL (polyglactic 910)”, and non-crimped fibers20084comprising oxidized regenerated cellulose can be needle-punched together to form the nonwoven material20080. In various embodiments, the nonwoven material20080can comprise approximately 5% to 50% crimped “VICRYL (polyglactic 910)” fibers20086by weight and approximately 5% to 50% non-crimped oxidized regenerated cellulose (ORC) fibers20084by weight, for example. When the nonwoven material20080contacts tissue T, the non-crimped ORC fibers20084can rapidly react with plasma in the tissue to form a gelatinous mass, for example. In various embodiments, the formation of the gelatinous ORC mass can be instantaneous or nearly instantaneous with the tissue contact. Further, after the formation of the gelatinous ORC mass, the crimped “VICRYL (polyglactic 910)” fibers20086can remain dispersed throughout the nonwoven material20080. For example, the crimped fibers20086can be suspended in the gelatinous ORC mass. As the gelatinous ORC mass is bioabsorbed, the crimped “VICRYL (polyglactic 910)” fibers20086can exert a springback force on adjacent tissue, as described in greater detail herein. Further, the tissue can begin to heal around the “VICRYL (polyglactic 910)” fibers and/or the formed staples30030, as also described in greater detail herein. In at least one embodiment, referring primarily toFIGS.78-81, the support portion20010of the staple cartridge20000can comprise a cartridge body20017, a top deck surface20011, and a plurality of staple cavities20012. Similar to the embodiments described herein, each staple cavity20012can define an opening in the deck surface20011. A staple20030can be removably positioned in a staple cavity20012. In various embodiments, a single staple20030is disposed in each staple cavity20012. In at least one embodiment, referring primarily toFIGS.82and83and similar to the staples described herein, each staple20030can comprise a base20031having a first end20035and a second end20036. A staple leg20032can extend from the first end20035of the base20031and another staple leg20032can extend from the second end20036of the base20031. Referring again toFIGS.78-81, prior to the deployment of the staples20030, the base20031of each staple20030can be supported by a staple driver20040positioned within the rigid support portion20010of the staple cartridge20000. Also prior to deployment of the staples20030, the legs20032of each staple20030can be at least partially contained within a staple cavity20012. In various embodiments, the staples20030can be deployed between an initial position and a fired position. For example, referring primarily toFIG.81, staples20030can be in an initial position (staples20030e,20030f), a partially fired or intermediate position (staples20030c,20030d), or a fired position (staples20030a,20030b). A driver20040can motivate the staples between the initial position and the fired position. For example, the base20031of each staple20030can be supported by a driver20040. The legs20032of a staple (staples20030e,20030finFIG.80, for example) can be positioned within a staple cavity20012. As the firing member or staple-firing sled20050translates from the proximal end20001to the distal end20002of the staple cartridge20000, an inclined surface20051on the sled20050can contact an inclined surface20042on a driver20040to deploy the staple20030positioned above to the contacted driver20040. In various embodiments, the staples20030can be deployed between an initial position and a fired position such that the legs20032move through the nonwoven material20080of the tissue thickness compensator20020, penetrate the top surface20021of the tissue thickness compensator20020, penetrate tissue T, and contact an anvil20060(FIG.61) positioned opposite the staple cartridge20000in the end effector12. The staple legs20032can be deformed against the anvil20060and the legs20032of each staple20030can capture a portion of the nonwoven material20080and a portion of the tissue T. In the fired configuration (FIGS.82and83), each staple20030can apply a compressive force to the tissue T and to the tissue thickness compensator20020captured within the staple20030. Referring primarily toFIGS.80and81, the legs20032of each staple20030can be deformed downwardly toward the base20031of the staple20030to form a staple entrapment area20039. The staple entrapment area20039can be the area in which the tissue T and the tissue thickness compensator20020can be captured by a fired staple20030. In various circumstances, the staple entrapment area20039can be defined between the inner surfaces of the deformed legs20032and the inner surface of the base20031of a staple20030. The size of the entrapment area20039for a staple20030can depend on several factors such as the length of the legs, the diameter of the legs, the width of the base, and/or the extent in which the legs are deformed, for example. In various embodiments, when a nonwoven material20080is captured in a staple entrapment area20039, the captured portion of the nonwoven material20080can be compressed. The compressed height of the nonwoven material20080captured in a staple entrapment area20039can vary within the staple cartridge20000depending on the tissue T in that same staple entrapment area20039. For example, where the tissue T is thinner, the staple entrapment area20039may have more room for the nonwoven material20080and, as a result, the nonwoven material20080may not be as compressed as it would be if the tissue T were thicker. Where the tissue T is thicker, the nonwoven material20080can be compressed more to accommodate the thicker tissue T, for example. For example, referring toFIG.82, the nonwoven material20080can be compressed to a first height in a first staple entrapment area20039a, a second height in a second staple entrapment area20039b, a third height in a third staple entrapment area20039c, a fourth height in a fourth staple entrapment area20039d, and a fifth height in a fifth staple entrapment area20039e, for example. Similarly, as illustrated inFIG.83, the nonwoven material20080can be compressed to a first height in the first staple entrapment area20039a, a second height in the second staple entrapment area20039b, a third height in the third staple entrapment area20039c, and a fourth height in the fourth staple entrapment area20039d. In other embodiments, the compressed height of the nonwoven material20080can be uniform throughout the staple cartridge20010. In various embodiments, an applied force can move the nonwoven material20080from an initial uncompressed configuration to a compressed configuration. Further, the nonwoven material20080can be resilient, such that, when compressed, the nonwoven material20080can generate a springback or restoring force. When deformed, the nonwoven material20080can seek to rebound from the compressed or deformed configuration. As the nonwoven material20080seeks to rebound, it can exert a springback or restoring force on the tissue also captured in the staple entrapment area30039, as described in greater detail herein. When the applied force is subsequently removed, the restoring force can cause the nonwoven material to rebound from the compressed configuration. In various embodiments, the nonwoven material20080can rebound to the initial, uncompressed configuration or may rebound to a configuration substantially similar to the initial, uncompressed configuration. In various embodiments, the deformation of the nonwoven material20080can be elastic. In some embodiments, the deformation of the nonwoven material can be partially elastic and partially plastic. When a portion of the nonwoven material20080is compressed in a staple entrapment area20039, the crimped fibers20086in that portion of the nonwoven compensator20039can also be compressed or otherwise deformed. The amount a crimped fiber20086is deformed can correspond to the amount that the captured portion of the nonwoven material20080is compressed. For example, referring toFIG.63, the nonwoven material20080can be captured by deployed staples20030. Where the nonwoven material20080is more compressed by a deployed staple20030, the average deformation of crimped fibers20086can be greater. Further, where the nonwoven material20080is less compressed by a deployed staple, the average deformation of crimped fibers20086can be smaller. Similarly, referring toFIGS.82and83, in a staple entrapment area20039dwhere the nonwoven material20080is more compressed, the crimped fibers20086in that staple entrapment area20039dcan be, on average, more deformed. Further, in a staple entrapment area20039awhere the nonwoven material20080is less compressed, the crimped fibers20086in that staple entrapment area20039acan be, on average, less deformed. The ability of the nonwoven material20080to rebound from the deformed configuration, i.e., the resiliency of the nonwoven material20080, can be a function of the resiliency of the crimped fibers20086in the nonwoven material20080. In various embodiments, the crimped fibers20086can deform elastically. In some embodiments, deformation of the crimped fibers20086can be partially elastic and partially plastic. In various embodiments, compression of each crimped fiber20086can cause the compressed crimped fibers20086to generate a springback or restoring force. For example, the compressed crimped fibers20086can generate a restoring force as the fibers20086seek to rebound from their compressed configuration. In various embodiments, the fibers20086can seek to return to their initial, uncompressed configuration or to a configuration substantially similar thereto. In some embodiments, the crimped fibers20086can seek to partially return to their initial configuration. In various embodiments, only a portion of the crimped fibers20086in the nonwoven material20080can be resilient. When a crimped fiber20086is comprised of a linear-elastic material, the restoring force of the compressed crimped fiber20086can be a function of the amount the crimped fiber20086is compressed and the spring rate of the crimped fiber20086, for example. The spring rate of the crimped fiber20086can at least depend on the orientation, material, shape and/or size of the crimped fiber20086, for example. In various embodiments, the crimped fibers20086in the nonwoven material20080can comprise a uniform spring rate. In other embodiments, the spring rate of the crimped fibers20086in the nonwoven material20080can vary. When a crimped fiber20086having a large spring rate is greatly compressed, the crimped fiber20086can generate a large restoring force. When a crimped fiber20086having the same large spring rate is less compressed, the crimped fiber20086can generate a smaller restoring force. The aggregate of restoring forces generated by compressed crimped fibers20086in the nonwoven material20080can generate a combined restoring force throughout the nonwoven material20080of the tissue thickness compensator20020. In various embodiments, the nonwoven material20080can exert the combined restoring force on tissue T captured within a fired staple20030with the compressed nonwoven material20080. Furthermore, the number of crimped fibers20086per unit volume of nonwoven material20080can affect the spring rate of the nonwoven material20080. For example, the resiliency in a nonwoven material20080can be low when the number of crimped fibers20086per unit volume of nonwoven material20080is low, for example; the resiliency of the nonwoven material20080can be higher when the number of crimped fibers20086per unit volume of nonwoven material20080is higher, for example; and the resiliency of the nonwoven material20080can be higher still when the number of crimped fibers20086per unit volume of nonwoven material20080is even higher, for example. When the resiliency of the nonwoven material20080is low, such as when the number of crimped fibers20086per unit volume of nonwoven material20080is low, the combined restoring force exerted by the tissue thickness compensator20020on captured tissue T can also be low. When the resiliency of the nonwoven material20080is higher, such as when the number of crimped fibers20086per unit volume of nonwoven material20080is higher, the aggregate restoring force exerted by the tissue thickness compensator20020on captured tissue T can also be higher. In various embodiments, referring primarily toFIG.64, a nonwoven material20080′ of a tissue thickness compensator20020′ can comprise a therapeutic agent20088, such as a medicament and/or pharmaceutically active agent, for example. In various embodiments, the nonwoven material20080′ can release a therapeutically effective amount of the therapeutic agent20088. For example, the therapeutic agent20088can be released as the nonwoven material20080′ is absorbed. In various embodiments, the therapeutic agent20088can be released into fluid, such as blood, for example, passing over or through the nonwoven material20080′. Examples of therapeutic agents20088can include, but are not limited to, haemostatic agents and drugs such as, for example, fibrin, thrombin, and/or oxidized regenerated cellulose (ORC); anti-inflammatory drugs such as, for example, diclofenac, aspirin, naproxen, sulindac, and/or hydrocortisone; antibiotic and antimicrobial drugs or agents such as, for example, triclosan, ionic silver, ampicillin, gentamicin, polymyxin B, and/or chloramphenicol; and anticancer agents such as, for example, cisplatin, mitomycin, and/or adriamycin. In various embodiments, the therapeutic agent20088can comprise a biologic, such as a stem cell, for example. In some embodiments, the fibers20082of the nonwoven material20080′ can comprise the therapeutic agent20088. In other embodiments, the therapeutic agent20088can be added to the nonwoven material20080′ or otherwise integrated into the tissue thickness compensator20020′. In some embodiments, primarily referring toFIGS.70-70B, a tissue thickness compensator20520for an end effector12(FIG.61) can comprise a plurality of springs or coiled fibers20586. Similar to the crimped fibers20086described herein, the coiled fibers20586can be, for example, crimped, twisted, coiled, bent, crippled, spiraled, curled, and/or bowed within the tissue thickness compensator20520. In some embodiments, the coiled fibers20586can be wound around a mandrel to form a coiled or substantially coil-like shape. Similar to the embodiments described herein, the coiled fibers20586can be randomly oriented and/or randomly distributed throughout the tissue thickness compensator20520. In other embodiments, the coiled fibers20586can be systematically arranged and/or uniformly distributed throughout the tissue thickness compensator20520. For example, referring toFIG.70, the coiled fibers20586can comprise a longitudinal axis between a first end20587and a second end20589of the coiled fiber20586. The longitudinal axes of the coiled fibers20520in the tissue thickness compensator20520can be parallel or substantially parallel. In some embodiments, the first end20587of each coiled fiber20520can be positioned along a first longitudinal side20523of the tissue thickness compensator20520and the second end20589of each coiled fiber20586can be positioned along a second longitudinal side20524of the tissue thickness compensator20520. In such an arrangement, the coiled fibers20586can laterally traverse the tissue thickness compensator. In other embodiments, the coiled fibers20586can longitudinally or diagonally traverse the tissue thickness compensator20520. In various embodiments, similar to the crimped fibers20086described herein, the coiled fibers20586can comprise a polymeric composition. The crimped fibers20586can be at least partially elastic such that deformation of the crimped fibers20586generates a restoring force. In some embodiments, the polymeric composition of the coiled fibers20586can comprise polycaprolactone (PCL), for example, such that the coiled fibers20586are not soluble in a chlorophyll solvent. Referring toFIG.70A, the springs or coiled fibers20520can be retained in a compensation material20580. In various embodiments, the compensation material20580can hold the coiled fibers20586in a loaded position such that the coiled fibers20586exert a spring load on, or within, the compensation material20580. In certain embodiments, the compensation material20580can hold the coiled fibers20586in a neutral position where the coiled fibers20586are not exerting a spring load on, or within, the compensation material20580. The compensation material20580can be bioabsorbable and, in some embodiments, can comprise a foam, such as, for example, polyglycolic acid (PGA) foam. Furthermore, the compensation material20580can be soluble in a chlorophyll solvent, for example. In some embodiments the tissue thickness compensator can comprise coiled fibers20586that comprise polycaprolactone (PCL) and compensation material20580that comprises polyglycolic acid (PGA) foam, for example, such that the coiled fibers20520are not soluble in a chlorophyll solvent while the compensation material20580is soluble in the chlorophyll solvent. In various embodiments, the compensation material20580can be at least partially elastic, such that compression of the compensation material20580generates a restoring force. Further, similar to the embodiments described herein, referring toFIG.70B, the compensation material20580of the tissue thickness compensator20520can comprise a therapeutic agent20588, such as stem cells, for example. The compensation material20580can release a therapeutically effective amount of the therapeutic agent20588as the compensation material20580is absorbed. Similar to the tissue thickness compensator20020described herein, the tissue thickness compensator20520can be compressible. For example, as staples20030(FIGS.78-81) are deployed from an initial position to a fired position, the staples20030can engage a portion of tissue thickness compensator20520. In various embodiments, a staple20030can capture a portion of the tissue thickness compensator20520and adjacent tissue T. The staple20030can apply a compressive force to the captured portion of the tissue thickness compensator20520and tissue T such that the tissue thickness compensator20520is compressed from a non-compressed height to a compressed height. Similar to the embodiments described herein, compression of the tissue thickness compensator20520can result in a corresponding deformation of the coiled fibers20586therein. As described in greater detail herein, deformation of each coiled fiber20586can generate a restoring force that can depend on the resiliency of the coiled fiber, for example, the amount the coiled fiber20586is deformed and/or the spring rate of the coiled fiber20586. The spring rate of the coiled fiber20586can at least depend on the orientation, material, shape and/or size of the coiled fiber20586, for example. Deformation of the coiled fibers20586in the tissue thickness compensator20520can generate restoring forces throughout the tissue thickness compensator20520. Similar to the embodiments described herein, the tissue thickness compensator20520can exert the aggregate restoring force generated by the deformed coiled fibers20586and/or the resilient compensation material20586on the captured tissue T in the fired staples20030. In some embodiments, primarily referring toFIGS.71and72, a tissue thickness compensator20620for an end effector12can comprise a plurality of spring coils20686. Similar to the crimped fibers20086and coiled fibers20586described herein, spring coils20686can be, for example, crimped, twisted, coiled, bent, crippled, spiraled, curled, and/or bowed within the tissue thickness compensator20620. In various embodiments, similar to the fibers and coils described herein, the spring coils20686can comprise a polymeric composition. Further, the spring coils20686can be at least partially elastic such that deformation of the spring coils20686generates a restoring force. The spring coils20686can comprise a first end20687, a second end20689, and a longitudinal axis therebetween. Referring toFIG.71, the first end20686of a spring coil20686can be positioned at or near a proximal end20626of the tissue thickness compensator and the second end20689of the same spring coil20686can be positioned at or near a distal end20625of the tissue thickness compensator20620such that the spring coil20686longitudinally traverses the tissue thickness compensator20620, for example. In other embodiments, the coiled fibers20686can laterally or diagonally traverse the tissue thickness compensator20620. The tissue thickness compensator20620can comprise an outer film20680that at least partially surrounds at least one spring coil20686. In various embodiments, referring toFIG.71, the outer film20680can extend around the perimeter of multiple spring coils20686in the tissue thickness compensator20620. In other embodiments, the outer film20680can completely encapsulate the spring coils20686or at least one spring coil20686in the tissue thickness compensator20620. The outer film20680can retain the spring coils20686in the end effector12. In various embodiments, the outer film20680can hold the spring coils20686in a loaded position such that the spring coils20686generate a spring load and exert a springback force on the outer film20680. In other embodiments, the outer film20680can hold the spring coils20686in a neutral position. The tissue thickness compensator20620can also comprise a filling material20624. In some embodiments, the filling material20624can be retained within and/or around the spring coils20686by the outer film20680. In some embodiments, the filling material20624can comprise a therapeutic agent20688, similar to the therapeutic agents described herein. Further, the filling material20624can support the spring coils20686within the tissue thickness compensator20620. The filling material20624can be compressible and at least partially resilient, such that the filling material20624contributes to the springback or restoring force generated by the tissue thickness compensator20620, as described in greater detail herein. Similar to the tissue thickness compensators described herein, the tissue thickness compensator20620can be compressible. As staples20030(FIGS.78-81) are deployed from an initial position to a fired position, in various embodiments, the staples20030can engage a portion of the tissue thickness compensator20620. In various embodiments, each staple20030can capture a portion of the tissue thickness compensator20620along with adjacent tissue T. The staple20030can apply a compressive force to the captured portion of the tissue thickness compensator20620and the captured tissue T such that the tissue thickness compensator20620is compressed between a non-compressed height and a compressed height. Similar to the embodiments described herein, compression of the tissue thickness compensator20620can result in a corresponding deformation of the spring coils20686retained therein (FIG.72). As described in greater detail herein, deformation of each spring coils20686can generate a restoring force that depends on the resiliency of the spring coil20686, for example, the amount the spring coil20686is deformed and/or the spring rate of the spring coil20686. The spring rate of a spring coil20686can at least depend on the material, shape and/or dimensions of the spring coil20686, for example. Furthermore, depending on the resiliency of the filling material20624and the outer film20680, compression of the filling material20624and/or the outer film20680can also generate restoring forces. The aggregate of restoring forces generated at least by the deformed spring coils20686, the filling material20624and/or the outer film20680in the tissue thickness compensator20620can generate restoring forces throughout the tissue thickness compensator20620. Similar to the embodiments described herein, the tissue thickness compensator20620can exert the aggregate restoring force generated by the deformed spring coils20686on the captured tissue T in a fired staple20030. In various embodiments, primarily referring toFIGS.73-75, a tissue thickness compensator20720for an end effector12can comprise a plurality of spring coils20786. Similar to the coiled fibers and springs described herein, spring coils20786can be, for example, crimped, twisted, coiled, bent, crippled, spiraled, curled, and/or bowed within the tissue thickness compensator20720. The spring coils20786can be at least partially elastic such that deformation of the spring coils20786generates a restoring force. Further, the spring coils20786can comprise a first end20787, a second end20789, and a longitudinal axis therebetween. Referring primarily toFIG.75, the first end20787of the spring coil20786can be positioned at or near a proximal end20726of the tissue thickness compensator20720and the second end20789of the spring coil20786can be positioned at or near a distal end20725of the tissue thickness compensator20720such that the spring coil20786longitudinally traverses the tissue thickness compensator20720. In some embodiments, the spring coil20786can longitudinally extend in two parallel rows in the tissue thickness compensator20720. The tissue thickness compensator20720can be positioned in an end effector12such that a sled20050(FIG.61) or cutting element20052can translate along a slot20015between the parallel rows of spring coils20786. In other embodiments, similar to various embodiments described herein, the spring coils20786can laterally or diagonally traverse the tissue thickness compensator20720. Referring again toFIG.75, the spring coils20786can be retained or embedded in a compensation material20780. The compensation material20780can be bioabsorbable and, in some embodiments, can comprise foam, such as, for example, polyglycolic acid (PGA) foam. In various embodiments, the compensation material20780can be resilient such that deformation of the compensation material20780generates a springback force. The compensation material20780can be soluble in a chlorophyll solvent, for example. In some embodiments, for example, the tissue thickness compensator can comprise spring coils20786that comprise polycaprolactone (PCL) and compensation material20780that comprises polyglycolic acid (PGA) foam such that the spring coils20786are not soluble in a chlorophyll solvent while the compensation material20780is soluble in a chlorophyll solvent, for example. The compensation material20780can be at least partially resilient such that deformation of the compensation material20780generates a spring load or restoring force. In various embodiments, the tissue thickness compensator20720can comprise interwoven threads20790, which can extend between parallel rows of spring coils20786. For example, referring toFIG.75, a first interwoven thread20790can diagonally traverse the two parallel rows of spring coils20786and a second interwoven thread20790can also diagonally traverse the two parallel rows of spring coils20786. In some embodiments, the first and second interwoven threads20790can crisscross. In various embodiments, the interwoven threads20790can crisscross multiple times along the length of the tissue thickness compensator20720. The interwoven threads20790can hold the spring coils20786in a loaded configuration such that the spring coils20786are held in a substantially flat position in the tissue thickness compensator20720. In some embodiments, the interwoven threads20790that traverse the tissue thickness compensator20720can be directly attached to the spring coils20786. In other embodiments, the interwoven threads20790can be coupled to the spring coils20786via a support20792that extends through each spring coil20786along the longitudinal axis thereof. As described in greater detail herein, in various embodiments, a staple cartridge20000can comprise a slot20015configured to receive a translating sled20050comprising a cutting element20052(FIG.61). As the sled20050translates along the slot20015, the sled20050can eject staples20030from fastener cavities20012in the staple cartridge20000and the cutting element20052can simultaneously or nearly simultaneously sever tissue T. In various embodiments, referring again toFIG.75, as the cutting element20052translates, it can also sever the interwoven threads20790that crisscross between the parallel rows of spring coils20786in the tissue thickness compensator20720. As the interwoven threads20790are severed, each spring coil20786can be released from its loaded configuration such that each spring coil20786reverts from the loaded, substantially flat position to an expanded position in the tissue thickness compensator20720. In various embodiments, when a spring coil20786is expanded, the compensation material20780surrounding the spring coil20786can also expand. In various embodiments, as staples20030(FIGS.78-81) are deployed from an initial position to a fired position, the staples20030can engage a portion of the tissue thickness compensator20720and the tissue thickness compensator20720can expand, or attempt to expand, within the staples20030and can apply a compressive force to the tissue T. In various embodiments, at least one staple20030can capture a portion of the tissue thickness compensator20720, along with adjacent tissue T. The staple20030can apply a compressive force to the captured portion of the tissue thickness compensator20720and the captured tissue T, such that the tissue thickness compensator20720is compressed between a non-compressed height and a compressed height. Similar to the embodiments described herein, compression of the tissue thickness compensator20720can result in a corresponding deformation of the spring coils20786and compensation material20780retained therein. As described in greater detail herein, deformation of each spring coils20786can generate a restoring force that can depend on the resiliency of the spring coil, for example, the amount the spring coil20786is deformed and/or the spring rate of the spring coil20786. The spring rate of a spring coil20786can at least depend on the orientation, material, shape and/or size of the spring coil20786, for example. The aggregate of restoring forces generated by at least the deformed spring coils20786and/or the compensation material30380in the tissue thickness compensator20720can generate restoring forces throughout the tissue thickness compensator20720. Similar to the embodiments described herein, the tissue thickness compensator20720can exert the aggregate restoring force generated by the deformed spring coils20786in the tissue thickness compensator20720on the captured tissue T and fired staples20030. In various embodiments, primarily referring toFIGS.76and77, a tissue thickness compensator20820for a surgical end effector12can comprise a spring coil20886. Similar to the fibers and coils described herein, spring coil20886can be, for example, crimped, twisted, coiled, bent, crippled, spiraled, curled, and/or bowed within the tissue thickness compensator20820. The spring coil20886can comprise a polymeric composition and can be at least partially elastic, such that deformation of the spring coil20886generates a springback force. Further, the spring coil20886can comprise a first end20887and a second end20889. Referring toFIG.76, the first end20887can be positioned at or near a proximal end20826of the tissue thickness compensator20820and the second end20889can be positioned at or near a distal end20825of the tissue thickness compensator20820. The spring coil20886can wind or meander from the proximal end20825to the distal end20826of the tissue thickness compensator20820. Referring again toFIG.76, the spring coil20886can be retained or embedded in a compensation material20880. The compensation material20880can be bioabsorbable and, in some embodiments, can comprise a foam, such as, for example, polyglycolic acid (PGA) foam. The compensation material20880can be soluble in a chlorophyll solvent, for example. In some embodiments, the tissue thickness compensator can comprise spring coils20886comprising polycaprolactone (PCL) and compensation material20880comprising polyglycolic acid (PGA) foam, for example, such that the spring coil20886is not soluble in a chlorophyll solvent while the compensation material20880is soluble in a chlorophyll solvent. The compensation material20880can be at least partially resilient such that deformation of the compensation material20880generates a spring load or restoring force. Similar to tissue thickness compensators described herein, for example, the tissue thickness compensator20820can be compressible. Compression of the tissue thickness compensator20820can result in a deformation of at least a portion of the spring coil20886retained or embedded in the compensation material20880of the tissue thickness compensator20820. As described in greater detail herein, deformation of the spring coil20886can generate restoring forces that can depend on the resiliency of the spring coil20886, the amount the spring coil20886is deformed, and/or the spring rate of the spring coil20886, for example. The aggregate of restoring forces generated by the deformed spring coil20886and/or deformed compensation material20880can generate restoring forces throughout the tissue thickness compensator20820. The tissue thickness compensator20820can exert the aggregate restoring force on the captured tissue T in the fired staples20030. Referring now toFIG.84, a surgical end effector12can comprise a tissue thickness compensator30020having at least one tubular element30080. The tissue thickness compensator30020can be retained in the surgical end effector12. As described in greater detail herein, a fastener in the end effector12can be deployed such that the fastener moves to a fired position and deforms at least a portion of the tubular element30080in the tissue thickness compensator30020. The reader will appreciate that tissue thickness compensators comprising at least one tubular element as described herein can be installed in or otherwise engaged with a variety of surgical end effectors and that such embodiments are within the scope of the present disclosure. In various embodiments, still referring toFIG.84, the tissue thickness compensator30020can be positioned relative to the anvil30060of the end effector12. In other embodiments, the tissue thickness compensator30020can be positioned relative to a fastener cartridge assembly, such as staple cartridge30000, of the end effector12. In various embodiments, the staple cartridge30000can be configured to fit in a cartridge channel30072of a jaw30070of the end effector12. For example, the tissue thickness compensator30020can be releasably secured to the staple cartridge30000. In at least one embodiment, the tubular element30080of the tissue thickness compensator30020can be positioned adjacent to a top deck surface30011of a rigid support portion30010of the staple cartridge30000. In various embodiments, the tubular element30080can be secured to the top deck surface30011by an adhesive or by a wrap, similar to at least one of the wraps described herein (e.g.,FIG.16). In various embodiments, the tissue thickness compensator30020can be integral to an assembly comprises the staple cartridge30000such that the staple cartridge30000and the tissue thickness compensator30020are formed as a single unit construction. For example, the staple cartridge30000can comprise a first body portion, such as the rigid support portion30010, and a second body portion, such as the tissue thickness compensator30020, for example. Referring toFIGS.84-86, the tubular element30080in the tissue thickness compensator30020can comprise an elongate portion30082having at least one lumen30084that extends at least partially therethrough. Referring primarily toFIG.86, the elongate portion30082of the tubular element30080can comprise woven or braided strands30090, as described in greater detail herein. In other embodiments, the elongate portion30082can comprise a solid structure, such as a polymer extrusion, rather than woven strands30090. The elongate portion30082of the tubular element30080can comprise a thickness. In various embodiments, the thickness of the elongate portion30082can be substantially uniform throughout the length and around the diameter thereof; in other embodiments, the thickness can vary. The elongate portion30082can be elongated such that the length of the elongate portion30082is greater than the diameter of the elongate portion30082, for example. In various embodiments, the elongate portion can comprise a length of approximately 1.20 inches to approximately 2.60 inches and a diameter of approximately 0.10 inches to approximately 0.15 inches, for example. In some embodiments, the length of the tubular element20080can be approximately 1.40 inches, for example, and the diameter of the tubular element20080can be approximately 0.125 inches, for example. Furthermore, the elongate portion30082can define a substantially circular or elliptical cross-sectional shape, for example. In other embodiments, the cross-sectional shape can comprise a polygonal shape, such as, for example, a triangle, a hexagon and/or an octagon. Referring again toFIG.84, the tubular element30080can comprise a first distal end30083and a second proximal end30085. In various embodiments, the cross-sectional shape of the elongate portion30082can narrow at the first and/or second end30083,30085wherein at least one end30083,30085of the tubular element30080can be closed and/or sealed. In other embodiments, a lumen30084can continue through the distal ends30083,30085of the tubular element30080such that the ends30083,30085are open. In various embodiments, the tubular element30080can comprise a single central lumen30084that extends at least partially through the elongate portion30084. In some embodiments, the lumen30084can extend through the entire length of the elongate portion30084. In still other embodiments, the tubular element30080can comprise multiple lumens30084extending therethrough. Lumens30084extending through the tubular element30080can be circular, semi-circular, wedge-shaped, and/or combinations thereof. In various embodiments, a tubular element30080can also comprise support webs that can form a modified “T” or “X” shape, for example, within the lumen30084. In various embodiments, the dimensions, lumen(s), and/or support web(s) within the tubular element30080can define the cross-sectional shape of the tubular element30080. The cross-sectional shape of the tubular element30080can be consistent throughout the length thereof or, in other embodiments, the cross-sectional shape of the tubular element30080can vary along the length thereof. As described in greater detail herein, the cross-sectional shape of the tubular element30080can affect the compressibility and resiliency of the tubular element30080. In various embodiments, the tubular element30080can comprise a vertical diameter and a horizontal diameter; the dimensions thereof can be selected depending on the arrangement of the tubular element30080in the end effector12, the dimensions of the end effector12, including the tissue gap of the end effector12, and the expected geometry of the staple entrapment areas30039. For example, the vertical diameter of the tubular element30080can relate to the expected height of a formed staple. In such embodiments, the vertical diameter of the tubular element30080can be selected such that the vertical diameter can be reduced approximately 5% to approximately 20% when the tubular element30080is captured within a formed staple30030. For example, a tubular element30080having a vertical diameter of approximately 0.100 inches may be used for staples having an expected formed height of approximately 0.080 inches to approximately 0.095 inches. As a result, the vertical diameter of the tubular element30080can be reduced approximately 5% to approximately 20% when captured within the formed staple30030even when no tissue T is captured therein. When tissue T is captured within the formed staple30030, the compression of the tubular element30080may be even greater. In some embodiments, the vertical diameter can be uniform throughout the length of the tubular element30080or, in other embodiments, the vertical diameter can vary along the length thereof. In some embodiments, the horizontal diameter of the tubular element30080can be greater than, equal to, or less than the vertical diameter of the tubular element30080when the tubular element30080is in an undeformed or rebounded configuration. For example, referring toFIG.85, the horizontal diameter can be approximately three times larger than the vertical diameter, for example. In some embodiments the horizontal diameter can be approximately 0.400 inches and the vertical diameter can be approximately 0.125 inches, for example. In other embodiments, referring now toFIG.87, the horizontal diameter of a tubular element31080can be equal to or substantially equal to the vertical diameter of the tubular element31080when the tubular element31080is in an undeformed or rebounded configuration. In some embodiments the horizontal diameter can be approximately 0.125 inches and the vertical diameter can also be approximately 0.125 inches, for example. In various embodiments, the tubular element30080can comprise a vertical diameter of approximately 0.125 inches, a horizontal diameter of approximately 0.400 inches, and a length of approximately 1.400 inches. As described in greater detail herein, when a force A is applied to the tubular element30080and/or31080, the tubular element can deform such that the cross-sectional geometry, including the horizontal and vertical diameters, can change. Referring again toFIGS.84-86, the tubular element30080in the tissue thickness compensator30020can be deformable. In various embodiments, the entire tubular element30080can be deformable. For example, the tubular element30080can be deformable from the proximal end30083to the distal end30085of the elongate portion30082and around the entire circumference thereof. In other embodiments, only a portion of the tubular element30080can be deformable. For example, in various embodiments, only an intermediate length of the elongate portion30082and/or only a portion of the circumference of the tubular element30080can be deformable. When a compressive force is applied to a contact point on the elongate portion30082of the tubular element30080, the contact point can shift, which can alter the cross-sectional dimensions of the tubular element30080. For example, referring again toFIG.85, the tubular element30080can comprise a top apex30086and a bottom apex30088on the elongate portion30082. In the initial, undeformed configuration, the tubular element30080can comprise undeformed cross-sectional dimensions, including an undeformed vertical diameter between the top apex30086and the bottom apex30088. When a compressive force A is applied to the top apex30086, the tubular element30080can move to a deformed configuration. In the deformed configuration, the cross-sectional dimensions of the tube30080can be altered. For example, the tube30086can comprise a deformed vertical diameter between the top apex30086and the bottom apex30088, which can be less than the undeformed vertical diameter. In some embodiments, referring toFIG.87, the horizontal diameter of the deformed tube30080can be lengthened, for example, when the tubular element30080moves from an undeformed configuration to a deformed configuration. The deformed cross-sectional dimensions of the deformed tube30080can at least depend on the position, angular orientation, and/or magnitude of the applied force A. As described in greater detail herein, deformation of a tubular element30080can generate a springback or restoring force that can depend on the resiliency of the tubular element30080. Referring still toFIG.85, the tubular element30080can generate a springback or restoring force when compressed. In such embodiments, as described herein, the tubular element30080can move from an initial undeformed configuration to a deformed configuration when a force A is applied to a contact point on the elongate portion30082of the tubular element30080. When the applied force A is removed, the deformed tube30080can rebound from the deformed configuration. The deformed tube30080may rebound to the initial, undeformed configuration or may rebound to a configuration substantially similar to the initial, undeformed configuration. The ability of the tubular element30080to rebound from a deformed configuration relates to the resiliency of the tubular element30080. Referring again toFIG.85, a tubular element30080can exert a springback or restoring force. The restoring force can be generated by the tubular element30080when an applied force A is exerted on the tubular element30080, for example, by a staple30030(FIGS.88and89), as described in greater detail herein. An applied force A can alter the cross-sectional dimensions of the tubular element30080. Furthermore, in linear-elastic materials, the restoring force of each deformed portion of the tubular element30080can be a function of the deformed dimensions of the tubular element30080and the spring rate of that portion of the tubular element30080. The spring rate of a tubular element30080can at least depend on the orientation, material, cross-sectional geometry and/or dimensions of the tubular element30080, for example. In various embodiments, the tubular element30080in a tissue thickness compensator30020can comprise a uniform spring rate. In other embodiments, the spring rate can vary along the length and/or around the diameter of the tubular element30080. When a portion of a tubular element30080having a first spring rate is greatly compressed, the tubular element30080can generate a large restoring force. When a portion of the tubular element30080having the same first spring rate is less compressed, the tubular element30080can generate a smaller restoring force. Referring again toFIG.84, the tubular element30080in the tissue thickness compensator30020can comprise a polymeric composition. In some embodiments, the elongate portion30082of the tubular element30080can comprise the polymeric composition. Further, in various embodiments, the polymeric composition can comprise an at least partially elastic material such that deformation of the tubular element30080generates a restoring force. The polymeric composition can comprise non-absorbable polymers, absorbable polymers, or combinations thereof, for example. Examples of synthetic polymers include, but are not limited to, polyglycolic acid (PGA), poly(lactic acid) (PLA), polycaprolactone (PCL), polydioxanone (PDO), and copolymers thereof. In some embodiments, the absorbable polymers can include bioabsorbable, biocompatible elastomeric polymers, for example. Furthermore, the polymeric composition of the tubular element30080can comprise synthetic polymers, non-synthetic polymers, or combinations thereof, for example. In various embodiments, similar to the polymeric compositions in embodiments described herein, the polymeric composition of the tubular element30080can include varied amounts of absorbable polymers, non-absorbable polymers, synthetic polymers, and/or non-synthetic polymers, for example, by weight percentage. Referring toFIGS.84and85, the tubular element30080can comprise a therapeutic agent30098such as a pharmaceutically active agent or medicament, for example. In various embodiments, the therapeutic agent30098can be retained in the lumen30084of the tubular element30080. The elongate portion30082can encapsulate or partially encapsulate the therapeutic agent30098. Additionally or alternatively, the polymeric composition of the elongate portion30082can comprise the therapeutic agent30098. The tubular element30080can release a therapeutically effective amount of the therapeutic agent30098. In various embodiments, the therapeutic agent30098can be released as the tubular element30080is absorbed. For example, the therapeutic agent30098can be released into fluid (such as blood) passing over or through the tubular element30080. In still other embodiments, the therapeutic agent30098can be released when a staple30030(FIGS.88and89) pierces the tubular element30080and/or when the cutting element30052on the staple-firing sled30050(FIG.84) cuts a portion of the tubular element30080, for example. Examples of therapeutic agents30098can include, but are not limited to, haemostatic agents and drugs such as, for example, fibrin, thrombin, and/or oxidized regenerated cellulose (ORC), anti-inflammatory drugs such as, for example, diclofenac, aspirin, naproxen, sulindac, and/or hydrocortisone, antibiotic and antimicrobial drugs or agents such as, for example, triclosan, ionic silver, ampicillin, gentamicin, polymyxin B, and/or chloramphenicol, anticancer agents such as, for example, cisplatin, mitomycin, and/or adriamycin, and/or biologics such as, for example, stem cells. In various embodiments, referring again toFIGS.84,88and89, fasteners such as staples30030, for example, can be deployed from a staple cartridge30000such that the staples30030engage a tissue thickness compensator30020and apply a force A to a tubular element32080therein. As described herein, application of a force A to the tubular element30080can cause deformation of the tubular element30080. Similar to the end effectors12described herein, the rigid support portion30010of the staple cartridge30000can comprise a cartridge body30017, a deck surface30011, and a plurality of staple cavities30012therein. Each staple cavity30012can define an opening in the deck surface30011and a staple30030can be removably positioned in a staple cavity30012(FIG.104). In at least one embodiment, referring primarily toFIGS.88and89, each staple30030can comprise a base30031and two staple legs30032extending from the base30031. Prior to the deployment of the staples30030, the base30031of each staple30030can be supported by a staple driver30040(FIG.104) positioned within the rigid support portion30010of the staple cartridge30000. Also prior to the deployment of the staples30030, the legs30032of each staple30030can be at least partially contained within the staple cavity30012(FIG.104). In various embodiments, as described in greater detail herein, the staples30030can be deployed between an initial position and a fired position. For example, a staple-firing sled30050can engage a driver30040(FIG.104). to move at least one staple30030between the initial position and the fired position. In various embodiments, referring primarily toFIG.88, the staple30030can be moved to a fired position, wherein the legs30032of the staple30030engage a tubular element32080of a tissue thickness compensator32020, penetrate tissue T, and contact an anvil30060(FIG.104) positioned opposite the staple cartridge30000in the surgical end effector12. Staple forming pockets30062in the anvil30060can bend the staple legs30032such that the fired staple30030captures a portion of the tubular element32080and a portion of the tissue T in a staple entrapment area30039. As described in greater detail herein, at least one staple leg30032can pierce the tubular element32080of the tissue thickness compensator32020when the staple30030moves between the initial position and the fired position. In other embodiments, the staple legs30032can move around the perimeter of the tubular element32080such that the staple legs30032avoid piercing the tubular element32080. Similar to the fasteners described herein, the legs30032of each staple30030can be deformed downwardly toward the base30031of the staple30030to form a staple entrapment area30039therebetween. The staple entrapment area30039can be the area in which tissue T and a portion of the tissue thickness compensator32020can be captured by a fired staple30030. In the fired position, each staple30030can apply a compressive force to the tissue T and to the tissue thickness compensator32020captured within the staple entrapment area30039of the staple30030. In various embodiments, referring still toFIG.88, when the tubular element32080is captured in a staple entrapment area30039, the captured portion of the tubular element32080can be deformed, as described herein. Furthermore, the tubular element32080can be deformed to different deformed configurations in different staple entrapment areas30039depending on, for example, the thickness, compressibility, and/or density of the tissue T captured in that same staple entrapment area30039. In various embodiments, the tubular element32080in the tissue thickness compensator32080can extend longitudinally through successive staple entrapment areas30039. In such an arrangement, the tubular element32080can be deformed to different deformed configurations in each staple entrapment area30039along a row of fired staples30030. Referring now toFIG.89, tubular elements33080in a tissue thickness compensator33020can be laterally arranged in the staple entrapment areas30039along a row of fired staples30030. In various embodiments, the tubular elements33080can be retained by a flexible shell33210. In such arrangements, the tubular elements33080and flexible shell33210can be deformed to different deformed configurations in each staple entrapment area30039. For example, where the tissue T is thinner, the tubular elements33080can be compressed less and where the tissue T is thicker, the tubular elements33080can be compressed more to accommodate the thicker tissue T. In other embodiments, the deformed dimensions of the tubular elements33080can be uniform throughout the entire length and/or width of the tissue thickness compensator33020. Referring toFIGS.90-92, in various embodiments, a tubular element34080in a tissue thickness compensator34020can comprise a plurality of strands34090. Referring primarily toFIG.90, in some embodiments, the strands34090can be woven or braided into a tubular lattice34092forming the tubular element34080. The tubular lattice34092formed by the strands34090can be substantially hollow. The strands34090of the tubular element34080can be solid strands, tubular strands, and/or another other suitable shape. For example, referring toFIG.91, a single strand34090of the tubular lattice34092can be a tube. In various embodiments, referring toFIG.93, a strand34090can comprise at least one lumen34094extending therethrough. The number, geometry and/or dimensions(s) of the lumens34094can determine the cross-sectional shape of the strand34090. For example, a strand34090can comprise circular lumen(s), semi-circular lumen(s), wedge-shaped lumen(s), and/or combinations thereof. In various embodiments, a strand34090can also comprise support webs34096that can form a modified “T” or “X” shape, for example. At least the diameter of the strand34090, the lumen(s) extending therethrough, and the support web(s) can characterize the cross-sectional shape of a strand34090. The cross-sectional shape of each strand34090, as discussed in greater detail herein, can affect the springback or restoring force generated by the strand34090and the corresponding springback or restoring force generated by the tubular element34080. Referring toFIG.94, a tubular lattice34092of strands34090can be deformable. In various embodiments, the tubular lattice34092can produce or contribute to the deformability and/or the resiliency of the tubular element34080. For example, the strands34090of the tubular lattice34092can be woven together such that the strands34090are configured to slide and/or bend relative to each other. When a force is applied to the elongate portion34082of the tubular element34080, the strands34090therein may slide and/or bend such that the tubular lattice34092moves to a deformed configuration. For example, referring still toFIG.94, a staple30030can compress the tubular lattice34092and the tissue T captured in a staple entrapment area34039which can cause the strands34090of the tubular lattice34092to slide and/or bend relative to each other. A top apex34086of the tubular lattice34092can move towards a bottom apex34088of the tubular lattice34092when the tubular lattice34092is compressed to the deformed configuration in order to accommodate the captured tissue T in a staple entrapment area30039. In various circumstances, the tubular lattice34092captured in a fired stapled30030will seek to regain its undeformed configuration and can apply a restoring force to the captured tissue T. Further, the portions of the tubular lattice34092positioned between staple entrapment areas30039, i.e., not captured within a fired staple30030, can also be deformed due to the deformation of adjacent portions of the tubular lattice34092that are within the staple entrapment areas30039. Where the tubular lattice34092is deformed, the tubular lattice34092can seek to rebound or partially rebound from the deformed configuration. In various embodiments, portions of the tubular lattice34092can rebound to their initial configurations and other portions of the tubular lattice34092can only partially rebound and/or remain fully compressed. Similar to the description of the tubular elements herein, each strand34090can also be deformable. Further, deformation of a strand34090can generate a restoring force that depends on the resiliency of each strand34090. In some embodiments, referring primarily toFIGS.91and92, each strand34090of a tubular lattice34092can be tubular. In other embodiments, each strand34090of a tubular lattice34092can be solid. In still other embodiments, the tubular lattice30092can comprise at least one tubular strand34090, at least one solid strand34090, at least one “X”- or “T”-shaped strand34090, and/or a combination thereof. In various embodiments, the strands34090in the tubular element34080can comprise a polymeric composition. The polymeric composition of a strand34090can comprise non-absorbable polymers, absorbable polymers, or combinations thereof. Examples of synthetic polymers include, but are not limited to, polyglycolic acid (PGA), poly(lactic acid) (PLA), polycaprolactone (PCL), polydioxanone (PDO), and copolymers thereof. In some embodiments, the absorbable polymers can include bioabsorbable, biocompatible elastomeric polymers, for example. Furthermore, the polymeric composition of the strand34090can comprise synthetic polymers, non-synthetic polymers, and/or combinations thereof. In various embodiments, similar to the polymeric compositions in embodiments described herein, the polymeric composition of the strand34090can include varied amounts of absorbable polymers, non-absorbable polymers, synthetic polymers, and/or non-synthetic polymers, for example, by weight percentage. The strands34090in the tubular element34080can further comprise a therapeutic agent34098(FIG.91) such as a pharmaceutically active agent or medicament, for example. In some embodiments, the strand34090can release a therapeutically effective amount of the therapeutic agent34098. In various embodiments, the therapeutic agent34098can be released as the tubular strand34090is absorbed. For example, the therapeutic agent30098can be released into fluid, such as blood for example, passing over or through the strand34090. In still other embodiments, the therapeutic agent34098can be released when a staple30030pierces the strand34090and/or when the cutting element30052on the staple-firing sled30050(FIG.84) cuts a portion of the tubular lattice34092, for example. Examples of therapeutic agents34098can include, but are not limited to, haemostatic agents and drugs such as, for example, fibrin, thrombin, and/or oxidized regenerated cellulose (ORC), anti-inflammatory drugs such as, for example, diclofenac, aspirin, naproxen, sulindac, and/or hydrocortisone, antibiotic and antimicrobial drugs or agents such as, for example, triclosan, ionic silver, ampicillin, gentamicin, polymyxin B, and/or chloramphenicol, anticancer agents such as, for example, cisplatin, mitomycin, and/or adriamycin; and/or biologics such as, for example, stem cells. Referring toFIGS.95and96, a tubular element35080can comprise multiple layers35100of strands35090. In some embodiments, the tubular element35080can comprise multiple layers35100of tubular lattices35092. Referring toFIG.95, the tubular element35080can comprise a first layer35100aand a second layer35100bof strands35090, for example. Referring now toFIG.96, a tubular element35180of a tissue thickness compensator35120can comprise a third layer35100cof strands35090, for example. Furthermore, different layers35100in the tubular element35180can comprise different materials. In some embodiments, each layer35100a,35100b,35100ccan be bioabsorbable, wherein, in at least one embodiment, each layer35100a,35100b,35100ccan comprise a different polymeric composition. For example, the first layer35100acan comprise a first polymeric composition; the second layer35100bcan comprise a second polymeric composition; and the third layer35100ccan comprise a third polymeric composition. In such embodiments, layers35100a,35100b,35100cof the tubular element35180can be bioabsorbed at different rates. For example, the first layer35100acan absorb quickly, the second layer35100bcan absorb slower than the first layer35100a, and the third layer35100ccan absorb slower than the first layer35100aand/or the second layer35100b. In other embodiments, the first layer35100acan absorb slowly, the second layer35100bcan absorb faster than the first layer35100a, and the third layer35100ccan absorb faster than the first layer35100aand/or the second layer35100b. Similar to strands34090described herein, the strands35090in the tubular element35180can comprise a medicament35098. In various embodiments, referring again toFIG.95, to control elusion or release of the medicament(s)35098, the first layer35100aof strands35090comprising a medicament35098acan be bioabsorbed at a first rate and the second layer35100bof strands35090comprising a medicament30098bcan be bioabsorbed at a second rate. For example, the first layer35100acan absorb quickly to allow for a rapid initial release of the medicament35098aand the second layer35100bcan absorb slower to allow controlled release of the medicament30098b. The medicament35098ain the strands35090of the first layer30100acan be different than the medicament35098bin the strands35090of the second layer35100b. For example, the strands35090in the first layer35100acan comprise oxidized regenerated cellulose (ORC) and the strands35090in the second layer35100bcan comprise a solution comprising hyaluronic acid. In such embodiments, initial absorption of the first layer35100acan release oxidized regenerated cellulose to help control bleeding while subsequent absorption of the second layer35100bcan release a solution comprising hyaluronic acid to can help prevent the adhesion of tissue. In other embodiments, the layers35100a,35100bcan comprise the same medicament35098a,35098b. For example, referring again toFIG.96, strands35090in layers35100a,35100band35100ccan comprise an anticancer agent, such as, for example, cisplatin. Furthermore, the first layer35100acan absorb quickly to allow for a rapid initial release of cisplatin, the second layer35100bcan absorb slower to allow for a controlled release of cisplatin, and the third layer35100ccan absorb slowest to allow for a more extended, controlled release of cisplatin. In various embodiments, referring toFIGS.97and98, a tissue thickness compensator36020can comprise an overmold material36024. The overmold material36024can be formed outside a tubular element36080, inside a tubular element36080, or both inside and outside a tubular element36080. In some embodiments, referring toFIG.97, the overmold material36024can be coextruded both inside and outside the tubular element36080and, in at least one embodiment, the tubular element36080can comprise a tubular lattice36092of strands36090. Similar to the polymeric composition described herein, the overmold material36024can comprise polyglycolic acid (PGA), poly(lactic acid) (PLA), and/or any other suitable, bioabsorbable and biocompatible elastomeric polymers, for example. Further, the overmold material36024can be non-porous such that the overmold material36024forms a fluid-impervious layer in the tubular element36080. In various embodiments, the overmold material36024can define a lumen36084therethrough. Further to the discussion above, the tubular element36080and/or the strands36090in a tubular lattice36092can comprise a therapeutic agent36098. In some embodiments, referring still toFIGS.97and98, a non-porous overmold material36024can contain the medicament36098within an inner lumen36084a. Alternatively or additionally, the non-porous, overmold material36024can contain the medicament36098within an intermediate lumen36084b, such as, for example, the intermediate lumen36084bthat contains the tubular lattice36092of medicament-comprising strands36090. Similar to the above, the tubular element36080can be positioned relative to staple cavities30012and a cutting element30052in staple cartridge30000(FIG.84). In several such embodiments, the deployment of the staples30030and/or the translation of the cutting element30052can be configured to pierce or rupture the non-porous, overmold material36024such that the medicament36098contained in at least one lumen36084of the tubular element30080can be released from the lumen30084. In various embodiments, referring toFIG.99, a tubular element37080can comprise a non-porous film37110. The non-porous film37110can at least partially surround a tubular lattice37092or a first layer37100aand a second layer37100bof tubular lattices30092to provide a fluid-impervious cover similar to the overmold material36024described herein. As described herein, a tubular element can comprise at least one of a bioabsorbable material, a therapeutic agent, a plurality of strands, a tubular lattice, layers of tubular lattices, an overmold material, a non-porous film, or combinations thereof. For example, referring to FIG.FIG.100, a tubular element38080can comprise an overmold material38024and a plurality of strands38090positioned through a central lumen38084of the tubular element38080. In some embodiments, the strands38090can comprise a therapeutic agent38098. In other embodiments, for example, referring toFIG.101, a tubular element39080can comprise an overmold material39024and a therapeutic agent39098positioned in a central lumen39084of the tubular element39080, for example. In various embodiments, at least one of the tubular element39080and overmold material39024can comprise a fluidic therapeutic agent39098. In various embodiments, referring again primarilyFIG.84, the tubular element30080can be positioned relative to the rigid support portion30010of the staple cartridge30000. The tubular element30080can be longitudinally positioned adjacent to the rigid support portion30010. In some embodiments, the tubular element30080can be substantially parallel to or aligned with a longitudinal slot or cavity30015in the rigid support portion30010. The tubular element30080can be aligned with the longitudinal slot30015such that a portion of the tubular element30080overlaps a portion of the longitudinal slot30015. In such embodiments, a cutting element30052on the staple-firing sled30050can sever a portion of the tubular element30080as the cutting edge30052translates along the longitudinal slot30015. In other embodiments, the tubular element30080can be longitudinally positioned on a first or second side of the longitudinal slot30015. In still other embodiments, the tubular element30080can be positioned relative to the rigid support portion30010of the staple cartridge30000such that the tubular element30080laterally or diagonally traverses at least a portion of the rigid support portion30010. In various embodiments, referring toFIG.102for example, a tissue thickness compensator40020can comprise multiple tubular elements40080. In some embodiments, the tubular elements40080can comprise different lengths, cross-sectional shapes, and/or materials, for example. Further, the tubular elements40080can be positioned relative to the rigid support portion40010of the staple cartridge30000such that the tubular axes of the tubular elements40080are parallel to each other. In some embodiments, the tubular axes of tubular elements40080can be longitudinally aligned such that a first tubular element40080is positioned within another tubular element40080. In other embodiments, parallel tubular elements40080can longitudinally traverse the staple cartridge30000, for example. In still other embodiments, parallel tubular elements40080can laterally or diagonally traverse the staple cartridge30000. In various other embodiments, non-parallel tubular elements40080can be angularly-oriented relative to each other such that their tubular axes intersect and/or are not parallel to each other. Referring toFIGS.102-105, a tissue thickness compensator40020can have two tubular elements40080; a first tubular element40080acan be longitudinally positioned on a first side of the longitudinal slot30015in the rigid support portion30010and a second tubular element40080bcan be longitudinally positioned on a second side of the longitudinal slot30015. Each tubular element40080can comprise a tubular lattice40092of strands40090. In various embodiments, the staple cartridge30000can comprise a total of six rows of staple cavities30012, wherein three rows of staple cavities30012are positioned on each side of the longitudinal slot30015, for example. In such embodiments, the cutting edge30052on the translating staple-firing sled30050may not be required to sever a portion of the tubular element40080. Similarly, referring now toFIGS.106-107, a tissue thickness compensator41020can comprise two tubular elements41080a,41080blongitudinally arranged in the staple cartridge30000. Similar to the above, staples30030from three rows of staple cavities30012can engage one tubular element41080aand staples30030from three different rows of staple cavities30012can engage another tubular element41080b. In various embodiments, referring still toFIGS.106-107, deployed staples30030can engage the tubular element40080at different locations across the cross-section of the tubular element40080. As discussed herein, the springback resiliency and corresponding restoring force exerted by the tubular element41080can depend on the cross-sectional shape of the tubular element41080, among other things. In some embodiments, a staple30030positioned in a staple entrapment area30039located at or near an arced portion of the tubular element41080can experience a greater restoring force than a staple30030in a staple entrapment area30039positioned near a non-arced portion. Similarly, a staple30030positioned in staple entrapment area30039in the non-arced portion of the tubular element41080can experience a lesser restoring force than the restoring force experienced by a staple30030positioned at or nearer to the arced portion of the tubular element30080. In other words, the arced portions of a tubular element41080can have a greater spring rate than the non-arced portion of the tubular element41080owing to the possibility that a larger quantity of elastic material may be captured by the staples30030along such portions. In various embodiments, as a result, referring primarily toFIG.107, the restoring force generated by the tissue thickness compensator41020can be greater near staples30030aand30030cand less near staple30030bin tubular element30080a. Correspondingly, the restoring force generated by the tissue thickness compensator41020can be greater near staples30030dand30030fthan near staple30030ein tubular element30080b. Referring again toFIGS.102-105, in various embodiments, the cross-sectional geometries of strands40090comprising the tubular lattice40092can be selected in order to provide a desired springback resiliency and corresponding restoring force exerted by the tubular lattice40092. For example, referring again toFIG.103, strands40090apositioned in arced portions of the tubular element40080can comprise X-shaped cross-sections, whereas strands40090bpositioned in non-arced portions of the tubular element40080can comprise tubular cross-sections. In some embodiments, strands40090aand40090bcomprising different cross-sectional geometries can be woven together to form the tubular lattice40092. In other embodiments, the strands40090aand40090bcan be attached to one another with an adhesive, for example. Referring toFIGS.104and105, the different cross-sectional geometries of strands40090in the tubular element40080can optimize the restoring force experienced in staple entrapment areas30039across the staple cartridge30000. In some embodiments, specific cross-sectional geometries can be selected such that the springback constant in staple entrapment areas30039across the staple cartridge is substantially balanced or equal. In some embodiments, referring toFIG.108, the tubular elements41080a,41080bof a tissue thickness compensator41120can be fastened together by an adjoining portion41126. Though the translating cutting element30052can be configured to pass between tubular elements41080aand41080b, the cutting element30052can be required to sever at least a portion of the adjoining portion41126. In some embodiments, the adjoining portion41126can comprise a soft material, such as, for example, a foam or gel, which is easily severed by the translating cutting element30052. In various embodiments, the adjoining portion41026can releasably secure the tissue thickness compensator41120to the surgical end effector12. In at least one embodiment, the adjoining portion41126can be fixed to the top deck surface30011of the rigid support portion30010such that the adjoining portion41126remains retained in the surgical end effector12after the tubular elements41080a,41080bare released therefrom. In various embodiments, referring toFIGS.109-110, a tissue thickness compensator42020can comprise multiple tubular elements42080such that the number of tubular elements42080is the same as the number of rows of staple cavities30012in the staple cartridge30000, for example. In at least one embodiment, the staple cartridge30000can comprise six rows of staple cavities30012and the tissue thickness compensator42020can comprise six tubular elements42080. Each tubular element42080can be substantially aligned with a row of staple cavities30012. When staples30030are ejected from a row of staple cavities30012, each staple30030from that row can pierce the same tubular element42080(FIG.110). In various embodiments, the deformation of one tube42080can have little or no impact on the deformation of an adjacent tube42080. Accordingly, the tubular elements42080can exert a substantially discrete and customized springback force in staple entrapment areas30039across the width of the staple cartridge30030. In some embodiments, where staples30030fired from multiple rows of staple cavities30012engage the same tubular element35080(FIG.107), the deformation of the tubular element35080can be less customized. For example, the deformation of a tubular element35080in a staple entrapment area30039in a first row can impact the deformation of that tubular element35080in staple entrapment area30039in another row. In at least one embodiment, the translating cutting edge30052can avoid severing the tubular elements42080. In other embodiments, referring toFIG.111, a tissue thickness compensator43020can comprise more than six tubular elements43080, such as, for example, seven tubular elements44080. Further, the tubular elements43080can be symmetrically or non-symmetrically arranged in the end effector12. When an odd number of tubular elements43080are longitudinally and symmetrically arranged in the end effector12, the translating cutting element30052can be configured to sever the middle tubular element that overlies the longitudinal channel30015. In various embodiments, referring toFIG.112, a tissue thickness compensator44020can comprise a central tubular element44080bthat is at least partially aligned with the longitudinal slot30015in the rigid support portion33010of the staple cartridge30000. The tissue thickness compensator44020can further comprise at least one peripheral tubular element44080a,44080clocated on a side of the longitudinal slot30015. For example, the tissue thickness compensator44020can comprise three tubular elements44080: a first peripheral tubular element44080acan be longitudinally positioned on a first side of the longitudinal slot30015of the staple cartridge30000, a central tubular element44080bcan be substantially positioned over and/or aligned with the longitudinal slot30015, and a second peripheral tubular element44080ccan be longitudinally positioned on a second side of the longitudinal slot30015. In some embodiments, the central tubular element44080bcan comprise a horizontal diameter that is substantially elongated relative to the vertical diameter. In various embodiments, the central tubular element44080b, and/or any other tubular element, can overlap multiples rows of staple cavities30012. Referring still toFIG.112, the central tubular element44080bcan overlap four staple rows of staple cavities30012and each peripheral tubular element44080a,44080ccan overlap a single row of staple cavities30012, for example. In other embodiments, the central tubular element44080bcan overlap less than four rows of staple cavities30012, such as, for example, two rows of staple cavities30012, for example. Further, peripheral tubular elements44080a,44080ccan overlap more than one row of staple cavities30012, such as, for example, two rows of staple cavities30012. Referring now toFIG.113, a central tubular element44180bof a tissue thickness compensator44120can comprise a therapeutic agent44198in a lumen44184of the central tubular element44180b. In various embodiments, central tubular element44180band/or at least one peripheral tubular element44080a,44080ccan comprise the therapeutic agent44198and/or any other suitable therapeutic agent. In various embodiments, referring toFIG.114, the tissue thickness compensator44220can comprise a shell44224, which can be similar to overmold material32024described herein. In various embodiments, the shell44224retains multiple tubular elements44080in position in the end effector12. The shell44224can be coextruded with the tubular elements44080. In some embodiments, the tubular elements44080can comprise a tubular lattice44092of strands44090. Similar to the polymeric compositions described in embodiments herein, the shell44224can comprise polyglycolic acid (PGA), poly(lactic acid) (PLA), and/or any other suitable bioabsorbable, biocompatible elastomeric polymers, for example. Further, the shell44224can be non-porous such that the shell44224forms a fluid-impervious layer in the tissue thickness compensator44220, for example. Further to the discussion herein, the tubular element44080and/or the strands44090in the tubular lattice44092can comprise a therapeutic agent44098. In some embodiments, the non-porous shell44224can contain the therapeutic agent44098within the tissue thickness compensator. As described herein, the tubular element44080can be positioned relative to staple cavities30012and a cutting element30052in staple cartridge30000. In several such embodiments, deployment of the staples30030and/or translation of the cutting element30052can be configured to pierce or rupture the non-porous, shell44224such that the therapeutic agent44198contained therein can be released from the tissue thickness compensator44020. Referring toFIG.115, a tissue thickness compensator44320can comprise a central tubular element44380bcomprising a tubular lattice44392. The tubular lattice44392can have a non-woven portion or a gap44381that is substantially aligned with the longitudinal slot30015of the rigid support portion30010. In such embodiments, a woven portion of the tubular lattice44092of the tubular element44380bdoes not overlap the longitudinal slot30015. Accordingly, the cutting element30052on the translating staple-fire sled30052can translate along the longitudinal slot30015without severing an overlapping a woven portion of the tubular lattice44392. Though staples30030cand30030dpositioned adjacent to the gap44381in tubular element44380bmay receive less support from the tubular lattice44392structure, in some embodiments, additional features can provide support for those staples30030and/or additional restoring force in the staple entrapment areas30039thereof. For example, as described in greater detail herein, additional tubular elements, support webbing, springs and/or buttressing material can be positioned at least one of inside and outside tubular element44380bnear gap44381, for example. Referring now toFIGS.116-119, in various embodiments, a tissue thickness compensator45020can comprise multiple tubular elements45080that laterally traverse the staple cartridge30000. The tubular elements45080can be positioned perpendicular to the rows of staple cavities30012and/or the longitudinal axis of the rigid support portion30010of the staple cartridge30000. In some embodiments, referring toFIG.116, the tubular elements45080can traverse the longitudinal slot30015in the staple cartridge30000such that the cutting element30052on the staple-firing sled30050is configured to sever the tubular elements45080as the staple-firing sled30050translates along the longitudinal slot30015. In other embodiments, referring now toFIG.117, the tissue thickness compensator46020can comprise two sets of laterally traversing tubular elements46080. The first set of laterally traversing tubular elements46080acan be positioned on a first side of the longitudinal slot30015and the second set of laterally traversing tubular elements46080bcan be positioned on a second side of the longitudinal slot30015. In such an arrangement, the cutting element30052can be configured to pass between the two sets of tubular elements46080without severing a portion of the tubular elements46080. In other embodiments, the cutting element30052can sever at least one tubular element46080that traverses the longitudinal slot30015while at least one other tubular element46080does not traverse the longitudinal slot30015and is not severed by the cutting element30052. As the tubular elements45080laterally traverse the staple cartridge30000, referring toFIGS.118and119, a staple30030can engage at least one tubular element45080in each staple entrapment area30039. In such an arrangement, each tubular element45080can provide a discrete restoring force along the length of the staple cartridge30000. For example, referring primarily toFIG.119, the tubular elements45080positioned near the proximal end of the tissue thickness compensator45020where the tissue is thicker can be greatly compressed compared to the tubular elements45080positioned near to the distal end of the tissue thickness compensator45020where the tissue is thinner. As a result, the tubular elements45080positioned closer to the proximal end of the tissue thickness compensator45020can provide a greater restoring force than the restoring force that could be generated by the tubular elements46080positioned closer to the distal end of the tissue thickness compensator45020. Further, referring still toFIG.119, the deformation of one tube45080can have little or no impact on the deformation of an adjacent tube45080. Accordingly, the tubular elements45080can exert a substantially discrete and customized springback force in staple entrapment areas30039along the length of the staple cartridge30030. In some embodiments, where multiple staples30030fired from a single row of staple cavities30012engage the same tubular element35080, the deformation of the tubular element35080can be less customized. For example, the deformation of a tubular element35080in one staple entrapment area30039can impact the deformation of that tubular element35080in another staple entrapment area30039. In still other embodiments, referring toFIGS.120-125, tubular elements47080of the tissue thickness compensator47020can diagonally traverse the staple cartridge30000. The tubular elements47080can traverse the longitudinal slot30015of the staple cartridge30000such that the cutting element30052on the staple-firing sled30050is configured to sever the diagonally traversing tubular elements47080as the staple-firing sled30052translates along the longitudinal slot30015. In other embodiments, the tissue thickness compensator47020can comprise two sets of diagonally traversing tubular elements47080. A first set of diagonally traversing tubular elements47080can be positioned on a first side of the longitudinal slot30015and a second set of diagonally traversing tubular elements47080can be positioned on a second side of the longitudinal slot30015. In such an arrangement, the cutting element30052can pass between the two sets of tubular elements47080and may not sever any tubular element47080. Referring still toFIGS.120-123, the diagonally traversing tubular elements47080can be positioned in the staple cartridge30000such that a gap is defined between the tubular elements47080. A gap between adjacent tubular elements47080can provide space for horizontal expansion of the tubular elements47080when a compressive force is applied thereto, such as, for example, by tissue T captured within the staple entrapment area30039of the formed staple30030. The tubular elements47080can be connected across a gap by a film or sheet of material47024. The sheet of material can be positioned on at least one of the deck surface30011of the rigid support portion30010and/or the tissue contacting side of the tubular elements47080. In various embodiments, referring toFIGS.124and125, at least one diagonally traversing tubular element47080can be positioned relative to the staple cavities30012in the staple cartridge30000such that the tubular element47080is positioned between the legs30032of the staples30030deployed from multiple rows of staple cavities30012. As the staples30030are moved from the initial position to the fired position, as described in greater detail herein, the staple legs30032can remain positioned around the tubular element47080. Further, the staples can be deformed such that the staple legs30032wrap around the perimeter of the tubular element47080, for example. In such an arrangement, the staples30030can be configured to move to the fired or formed position without piercing the tubular element47080. Movement of the staple legs30032around the tubular element47080could in some embodiments, prevent the inadvertent release of a therapeutic agent47098retained therein. The selected angular orientation of each tubular element47080relative to the longitudinal slot30015of the staple cartridge30000can depend on the position of the staple cavities30012in the staple cartridge30000. For example, in some embodiments, the tubular elements47080can be positioned at an approximately forty-five (45) degree angle relative to the longitudinal slot30015of the staple cartridge30000. In other embodiments, the tubular elements47080can be positioned at a fifteen (15) to seventy-five (75) degree angle relative to the longitudinal slot30015of the staple cartridge30000, for example. Similar to descriptions throughout the present disclosure, multiple tubular elements in a tissue thickness compensator can be connected by a binding agent, wrap, webbing, overmold, compensation material, and/or any other suitable connecting adhesive or structure, for example. In various embodiments, referring toFIGS.126-128, a flexible shell48024may surround or encapsulate tubular elements48080in a tissue thickness compensator48020. In various embodiments, the flexible shell48024can restrain the tubular elements48080in the end effector12and can hold each tubular element48080in position, such as, for example, in longitudinal alignment with a row of staple cavities30012. In at least one embodiment, the tissue thickness compensator48020can comprise six tubular elements48080, for example. In various embodiments, the flexible shell48024can be sufficiently deformable and resilient to restrain the tubular elements48020encased therein while permitting deformation and rebound of the tubular elements48080. Further, in some embodiments, the flexible shell48024can tautly surround the tubular elements48080and can remain tautly engaged with the tubular elements48080as they deform and/or rebound. Referring toFIG.127, prior to the deployment of staples30030, the anvil30060can be pivoted or rotated downwardly to compress the tissue thickness compensator48020and tissue T between the anvil30060and the staple cartridge30000. Compression of the tissue thickness compensator48020can include a corresponding compression of the flexible shell48024and the tubular elements48020therein. As the tubular elements48020deform, the flexible shell48024can similarly deform. In various embodiments, the tubular elements48020can be uniformly compressed across the width of the staple cartridge30000and the flexible shell48024can experience a similarly uniform compression across the tubular elements48080. Referring toFIG.128, when the anvil30060is opened after the staples30030have been deployed from the staple cartridge30000, the tubular elements48080can rebound or partially rebound from the compressed configurations (FIG.127). In various embodiments, a tubular element48080can rebound such that the tubular element48080returns to its initial, undeformed configuration. In some embodiments, a tubular element48080can partially rebound such that the tubular element48080partially returns to its initial undeformed configuration. For example, the deformation of the tubular element48080can be partially elastic and partially plastic. As the tubular elements48080rebound, the flexible shell48024can remain tautly engaged with each tubular element48080. The tubular elements48080and flexible shell48024can rebound to such a degree that the tubular elements48080and tissue T fill the staple entrapment areas30039while the tubular elements48080exert an appropriate restoring force on the tissue T therein. Referring toFIG.129, in other embodiments, a tissue thickness compensator48120comprising six tubular elements48180retained in a flexible shell48124can be positioned on the anvil30060of the end effector12, for example. Referring toFIGS.130-133, a tissue thickness compensator49020can comprise a tubular element49080longitudinally positioned along the longitudinal axis of the anvil30060. In various embodiments, the tissue thickness compensator49020can be secured to the anvil30060of the end effector12by a compressible compensation material49024. Further, the compressible compensation material49024can surround or encapsulate the tubular element49080. Similar to the descriptions herein, the tubular element49080can comprise at least one therapeutic agent49098which may be released by the absorption of various components of the tissue thickness compensator49020, the piercing of the tubular element49080by staples30030fired from the staple cartridge30000, and/or by the cutting element30052. Referring toFIG.131, a staple cartridge30000can comprise staples30030positioned in staple cavities30012, wherein, prior to deployment of the staples30030, the anvil30060and the tissue thickness compensator49020attached thereto can pivot toward the staple cartridge30000and compress tissue T captured therebetween. In some embodiments, the tubular element49080of the tissue thickness compensator49020can be uniformly deformed along the length of the staple cartridge30000by the pivoting anvil30060(FIG.131). Referring toFIGS.132and133, the staple-firing sled30050can translate along the longitudinal slot30015in the staple cartridge30000and engage each driver30040positioned beneath a staple30030in a staple cavity30010, wherein each engaged driver30040can fire or eject the staple30030from the staple cavity30012. When the anvil30060releases pressure on the tissue T and the tissue thickness compensator49020, the tissue thickness compensator49020, including the tubular element49080and the compressible compensation material49024, can rebound or partially rebound from the compressed configurations (FIG.131) to a rebounded configuration (FIGS.132and133). The tubular element49080and compressible compensation material49024can rebound to such a degree that the tissue thickness compensator49020and tissue T fill the staple entrapment areas30039while the tissue thickness compensator49020exert an a restoring force on the captured tissue T. In various embodiments, referring toFIGS.124-126, two tissue thickness compensators50020a,50020bcan be positioned in the end effector12of a surgical instrument. For example, a first tissue thickness compensator50020acan be attached to the staple cartridge30000in the lower jaw30070and a second tissue thickness compensator50020bcan be attached to the anvil30060. In at least one embodiment, the first tissue thickness compensator50020acan comprise a plurality of tubular elements50080longitudinally arranged and retained in a first compensation material50024a. At least one tubular element50080can comprise a therapeutic agent50098, similar to the therapeutic agents described herein. The first compensation material50024acan be deformable or substantially rigid. Further, in some embodiments, the first compensation material50024acan hold the tubular elements50080in position relative to the staple channel30000. For example, the first compensation material50024acan hold each tubular element50080in longitudinal alignment with a row of staple cavities30012. In at least one embodiment, the second tissue thickness compensator50020bcan comprise the first compensation material50024a, a second compensation material50024band/or a third compensation material50024c. The second and third compensation material50024b,50024ccan be deformable or substantially rigid. Similar to at least one embodiment described herein, the anvil30060can pivot and apply a compressive force to the tissue thickness compensators50020a,50020band the tissue T between the anvil30060and the staple cartridge30000. In some embodiments, neither the first tissue thickness compensators50020anor the second tissue thickness compensators50020bcan be compressible. In other embodiments, at least one component of the first tissue thickness compensators50020aand/or the second tissue thickness compensators50020bcan be compressible. When the staples30030are fired from the staple cartridge30000, referring now toFIGS.135and136, each staple30030can pierce a tubular element50080retained in the first tissue thickness compensator50020a. As shown inFIG.135, the therapeutic agent50098retained in the tubular element50080can be released when a staple30030pierces the tubular element50080. When released, the therapeutic agent50098can coat the staple legs30032and tissue T surrounding the fired staple30030. In various embodiments, the staples30030can also pierce the second tissue thickness compensator50020bwhen the staples30030are fired from the staple cartridge30000. Referring toFIGS.137-140, a tissue thickness compensator51020can comprise at least one tubular element51080that laterally traverses the tissue thickness compensator51020. For example, referring toFIG.137, the tissue thickness compensator51020can be positioned relative to the staple cartridge30000such that a first end51083of the laterally traversing tubular element51080can be positioned near a first longitudinal side of the staple cartridge30000and a second end51085of the laterally traversing tubular element51080can be positioned near a second longitudinal side of the staple cartridge30000. In various embodiments, the tubular element51080can comprise a capsule-like shape, for example. As illustrated inFIG.138, the tubular element51080can be perforated between the first end51083and the second end51085and, in some embodiments, the tubular element51080can be perforated at or near the center51087of the tubular element51080. The tubular element51080can comprise a polymeric composition, such as a bioabsorbable, biocompatible elastomeric polymer, for example. Further, referring again toFIG.137, the tissue thickness compensator51020can comprise a plurality of laterally traversing tubular elements51080. In at least one embodiment, thirteen tubular elements51080can be laterally arranged in the tissue thickness compensator51020, for example. Referring again toFIG.137, the tissue thickness compensator51020can further comprise a compensation material51024that at least partially surrounds the tubular elements51080. In various embodiments, the compensation material51024can comprise a bioabsorbable polymer, such as, for example, lyophilized polysaccharide, glycoprotein, elastin, proteoglycan, gelatin, collagen, and/or oxidized regenerated cellulose (ORC). The compensation material51024can hold the tubular elements51080in position in the tissue thickness compensator51020. Further, the compensation material51024can be secured to the top deck surface30011of the rigid support portion30010of the staple cartridge30000such that the compensation material51020is securely positioned in the end effector12. In some embodiments, the compensation material51024can comprise at least one medicament51098. Still referring toFIG.137, laterally positioned tubular elements51080can be positioned relative to the translating cutting element30052such that the cutting element30052is configured to sever the tubular elements51080. In various embodiments, the cutting element30052can sever the tubular elements51080at or near the perforation therein. When the tubular elements51080are severed in two halves, the severed portions of the tubular elements51080can be configured to swell or expand, as illustrated inFIG.139. For example, in various embodiments, the tubular element51080can comprise a hydrophilic substance51099that can be released and/or exposed when the tubular element51080is severed. Furthermore, when the hydrophilic substance51099contacts bodily fluids in tissue T, the hydrophilic substance51099can attract the fluid, which can cause the tubular element51080to swell or expand. As the tubular element51080expands, the compensation material51024surrounding the tubular element51080can shift or adjust to accommodate the swollen tubular element51080. For example, when the compensation material51024comprises gelatin, the gelatin can shift to accommodate the swollen tubular elements51080. Referring now toFIG.140, expansion of the tubular elements51080and shifting of the compensation material51024can cause a corresponding expansion of the tissue thickness compensator51020. Similar to other tissue thickness compensators discussed throughout the present disclosure, the tissue thickness compensator51020can be deformed or compressed by an applied force. Further, the tissue thickness compensator51020can be sufficiently resilient such that it produces a springback force when deformed by the applied force and can subsequently rebound or partially rebound when the applied force is removed. In various embodiments, when the tissue thickness compensator51020is captured in a staple entrapment area30039, the staple30030can deform the tissue thickness compensator51020. For example, the staple30030can deform the tubular elements51080and/or the compensation material51024of the tissue thickness compensator51020that are captured within the fired staple30030. In various embodiments, non-captured portions of the tissue thickness compensator51020can also be deformed due to the deformation in the staple entrapment areas30039. When deformed, the tissue thickness compensator51020can seek to rebound from the deformed configuration. In various embodiments, such a rebound may occur prior to the hydrophilic expansion of the tubular element51080, simultaneously with the hydrophilic expansion of the tubular element51080, and/or after the hydrophilic expansion of the tubular element51080. As the tissue thickness compensator51020seeks to rebound, it can exert a restoring force on the tissue also captured in the staple entrapment area30039, as described in greater detail herein. In various embodiments, at least one of the tubular elements51080and/or the compensation material51024in the tissue thickness compensator51020can comprise a therapeutic agent51098. When the tubular element51080that contains a therapeutic agent51098is severed, the therapeutic agent51098contained within the tubular elements51080can be released. Furthermore, when the compensation material51024comprises the therapeutic agent51098, the therapeutic agent51098can be released as the bioabsorbable compensation material51024is absorbed. In various embodiments, the tissue thickness compensator51020can provide for a rapid initial release of the therapeutic agent51098followed by a controlled release of the therapeutic agent51098. For example, the tissue thickness compensator51020can provide a rapid initial release of the therapeutic agent51098from the tubular elements51080to the tissue T along the cut line when the tubular elements51080comprising the therapeutic agent51098are severed. Further, as the bioabsorbable compensation material51024comprising the therapeutic agent51098is absorbed, the tissue thickness compensator51020can provide an extended, controlled release of the therapeutic agent51098. In some embodiments, at least some of the therapeutic agent51098can remain in the tubular element51080for a short period of time before the therapeutic agent51098flows into the compensation material51024. In other embodiments, at least some of the therapeutic agent51098can remain in the tubular element51080until the tubular element51080is absorbed. In various embodiments, the therapeutic agent51098released from the tubular element51080and the compensation material51024can be the same. In other embodiments, the tubular element51080and the compensation material51024can comprise different therapeutic agents or different combinations of therapeutic agents, for example. Referring still toFIG.140, in various embodiments, the end effector12can cut tissue T and fire staples30030into the severed tissue T nearly simultaneously or in quick succession. In such embodiments, a staple30030can be deployed into the tissue T immediately after the cutting element30052has severed the tubular element51080adjacent to the tissue T. In other words, the staples30030can engage the tissue thickness compensator51020immediately following or simultaneously with the swelling of the tubular element51080and the expansion of the tissue thickness compensator51020. In various embodiments, the tissue thickness compensator51020can continue to grow or expand after the staples30030have been fired into the tissue T. In various embodiments, the staples30030can be configured to puncture the tubular elements51080when the staples30030are deployed. In such embodiments, therapeutic agents51098still retained in the severed tubular elements51080can be released from the tubular elements51080and, in some embodiments, can cover the legs30031of the fired staples30030. Referring toFIG.141, the tissue thickness compensator51020can be manufactured by a molding technique, for example. In various embodiments, a frame, or a mold,51120can comprise a first longitudinal side51122and a second longitudinal side51124. Each longitudinal side51124can comprise one or more notches51130, which can each be configured to receive the first or second end50183,50185of a tubular element51080. In some embodiments, the first end50183of the tubular element51080can be positioned in a first notch51130aon the first longitudinal side51122and the second end50183of the tubular element51080can be positioned in a second notch51130bon the second longitudinal side51124such that the tubular element51080laterally traverses the frame51120. In various embodiments, the notch51180can comprise a semi-circular groove, which can securely fit the first or second end50183,50185of the tubular element51080therein. In various embodiments, the first notch51130acan be positioned directly across from the second notch51130band the tubular element51080can be positioned perpendicular, or at least substantially perpendicular, to the longitudinal axis of the frame51120. In other embodiments, the first notch51130acan be offset from the second notch51130bsuch that the tubular element51080is angularly positioned relative to the longitudinal axis of the frame51120. In still other embodiments, at least one tubular element51080can be longitudinally positioned within the frame51120such that the tubular element extends between the lateral sides51126,51128of the frame51120. Further, at least one tubular element can be angularly positioned in the frame between two notches on the lateral sides51126,51128of the frame and/or between a notch on a lateral side51126and a notch on a longitudinal side51124, for example. In various embodiments, the frame51120can comprise a support ledge51136, which can support the tubular elements51080positioned within the frame51120. In various embodiments, the frame51120can comprise notches51130to accommodate twelve tubular elements51080, for example. In some embodiments, the frame notches51130can be filled with tubular elements51080while, in other embodiments, less than all of the notches51130may be filled. In various embodiments, at least one tubular element51080can be positioned in the frame51120. In some embodiments, at least half the notches51130can receive tubular elements51080. In at least one embodiment, once the tubular elements51080are positioned in the frame51120, compensation material51024can be added to the frame51120. The compensation material51024can be fluidic when added to the frame51120. For example, in various embodiments, the compensation material51024can be poured into the frame51120and can flow around the tubular elements51080positioned therein. Referring toFIG.142, the fluidic compensation material51024can flow around the tubular element51080supported by notches51130in the frame51120. After the compensation material51024cures, or at least sufficiently cures, referring now toFIG.143, the tissue thickness compensator51020comprising the compensation material51024and tubular elements51080can be removed from the frame51120. In at least one embodiment, the tissue thickness compensator51020can be trimmed. For example, excess compensation material51024can be removed from the tissue thickness compensator51020such that the longitudinal sides of the compensation material are substantially planar. Furthermore, in some embodiments, referring toFIG.144, the first and second ends50183,50185of the tubular elements51080can be pressed together, or closed, to seal the tubular element51080. In some embodiments, the ends can be closed before the tubular elements51080are placed in the frame51120. In other embodiments, the trimming process may transect the ends51083,51085and a heat stacking process can be used to seal and/or close the ends51083,51085of the tubular elements51080. In various embodiments, referring again toFIG.141, a stiffening pin51127can be positioned within each tubular element51080. For example, the stiffening pin51127can extend through a longitudinal lumen of the tubular element51080. In some embodiments, the stiffening pin51127can extend beyond each tubular element51080such that the stiffening pin51127can be positioned in notches51130in the frame51120. In embodiments having stiffening pins51127, the stiffening pins51127can support the tubular elements51080when the compensation material51204is poured into the frame51120and as the fluidic compensation material51024flows around the tubular elements51080, for example. Once the compensation material51024cures, solidifies, and/or lyophilizes or sufficiently cures, solidifies, and/or lyophilizes the tissue thickness compensator51020can be removed from the frame51120and the stiffening pins51127can be removed from the longitudinal lumens of the tubular elements51080. In some embodiments, the tubular elements51080can then be filled with medicaments, for example. Similar to at least one embodiment described herein, after the tubular elements51080are filled with medicaments, the tissue thickness compensator51020, including the ends51083,51085of the tubular elements51080, for example, can be trimmed. In various embodiments, the tissue thickness compensator51020can be die cut, for example, and/or sealed by heat and/or pressure, for example. As discussed herein, the tissue thickness compensator52020can comprise multiple tubular elements51080. Referring now toFIG.145, the tubular elements51080can comprise different material properties, dimensions and geometries. For example, a first tubular element51080acan comprise a first thickness and a first material and a second tubular element51080bcan comprise a second thickness and a second material. In various embodiments, at least two tubular elements51080in the tissue thickness compensator52020can comprise the same material. In other embodiments, each tubular element51080in the tissue thickness compensator5202can comprise different materials. Similarly, in various embodiments, at least two tubular elements51080in the tissue thickness compensator52020can comprise the same geometry. In other embodiments, each tubular element51080in the tissue thickness compensator52020can comprise different geometries. Referring now toFIGS.208-211, a tissue thickness compensator51220can comprise at least one tubular element51280that laterally traverses the tissue thickness compensator51220. In various embodiments, referring toFIG.208, the tissue thickness compensator51220can be positioned relative to the anvil30060of the end effector12. The tissue thickness compensator51220can be secured to a securing surface30061of the anvil30060of the end effector12, for example. In various embodiments, referring primarily toFIG.209, the tubular element51280can comprise a capsule-like shape, for example. The tubular element51280can comprise a polymeric composition, such as a bioabsorbable, biocompatible elastomeric polymer, for example. Referring again toFIG.208, the tissue thickness compensator51220can further comprise a compensation material51224that at least partially surrounds the tubular elements51280. In various embodiments, the compensation material51224can comprise a bioabsorbable polymer, such as, for example, lyophilized polysaccharide, glycoprotein, elastin, proteoglycan, gelatin, collagen, and/or oxidized regenerated cellulose (ORC), for example. Similar to the above, the compensation material51024can hold the tubular elements51280in position in the tissue thickness compensator51220. Further, the compensation material51224can be secured to the securing surface30061of the anvil30060such that the compensation material51220is securely positioned in the end effector12. In some embodiments, the compensation material51224can comprise at least one medicant. Still referring toFIG.208, the laterally positioned tubular elements51280can be positioned relative to the cutting element30252on a translating sled30250such that the translatable cutting element30252is configured to sever the tubular elements51280. In various embodiments, the cutting element30252can sever the tubular elements51280at or near the center of each tubular element51280, for example. When the tubular elements51280are severed in two halves, the severed portions of the tubular elements51280can be configured to swell or expand, as illustrated inFIG.208. Referring primarily toFIG.210, in various embodiments, a tubular element51280can comprise a hydrophilic substance51099that can be released and/or exposed when the tubular element51280is severed. Furthermore, referring now toFIG.211, when the hydrophilic substance51099contacts bodily fluids in the tissue T, the hydrophilic substance51099can attract the fluid, which can cause the tubular element51280to swell or expand. As the tubular element51280expands, the compensation material51224surrounding the tubular element51280can shift or adjust to accommodate the swollen tubular element51280. For example, when the compensation material51224comprises gelatin, the gelatin can shift to accommodate the swollen tubular element51280. Referring again toFIG.208, expansion of the tubular elements51280and shifting of the compensation material51224can cause a corresponding expansion of the tissue thickness compensator51220. Similar to other tissue thickness compensators discussed throughout the present disclosure, the tissue thickness compensator51220can be deformed or compressed by an applied force. Further, the tissue thickness compensator51220can be sufficiently resilient such that it produces a springback force when deformed by the applied force and can subsequently rebound or partially rebound when the applied force is removed. In various embodiments, when the tissue thickness compensator51220is captured in a staple entrapment area30039(FIG.88), the staple30030can deform the tissue thickness compensator51220. For example, the staple30030can deform the tubular elements51280and/or the compensation material51224of the tissue thickness compensator51220captured within the fired staple30030. In various embodiments, non-captured portions of the tissue thickness compensator51220can also be deformed due to the deformation in the staple entrapment areas30039. When deformed, the tissue thickness compensator51220can seek to rebound from the deformed configuration. In various embodiments, such a rebound may occur prior to the hydrophilic expansion of the tubular element51280, simultaneously with the hydrophilic expansion of the tubular element51280, and/or after the hydrophilic expansion of the tubular element51280. As the tissue thickness compensator51220seeks to rebound, it can exert a restoring force on the tissue also captured in the staple entrapment area30039, as described in greater detail herein. Referring toFIGS.146-149, a tissue thickness compensator52020can comprise one or more tubular elements52080that laterally traverse the tissue thickness compensator52020, similar to at least one tissue thickness compensator described herein. In various embodiments, the tissue thickness compensator52020can comprise multiple laterally traversing tubular elements52080. The tissue thickness compensator52020can further comprise one or more sheets of material52024that hold or retain at least one tubular element52080in the tissue thickness compensator52020. In various embodiments, the one or more sheets of material52024can be positioned above and/or below the tubular elements52080and can securely retain each tubular element52080in the tissue thickness compensator52020. Referring primarily toFIG.146, the tissue thickness compensator can comprise a first sheet of material52024aand a second sheet of material52024b. In various embodiments, the tubular elements52080can be positioned between the first and second sheets of material52024a,52024b. Further, referring still toFIG.146, the sheet of material52024bcan be secured to the top deck surface30011of the rigid support portion of the staple cartridge30000such that the tissue thickness compensator52020is securely positioned in the end effector12. In other embodiments, one or more of the sheets of material52024can be secured to the anvil30060or otherwise retained in the end effector12. In various embodiments, referring primarily toFIG.147, the tissue thickness compensator52020can be porous and/or permeable. For example, the sheet of material52024can comprise a plurality of apertures52026. In various embodiments, the apertures52026can be substantially circular. In at least one embodiment, the apertures52036can be visible in the sheet of material52024. In other embodiments, the apertures52036can be microscopic. Referring still toFIG.147, the tubular elements52080can comprise a plurality of apertures52026, as well. In various embodiments, referring toFIG.148, a tissue thickness compensator52120can comprise a sheet of material52124that comprises a plurality of non-circular apertures52126. For example, the apertures52126can comprise a diamond and/or slotted shape. In various other embodiments, referring toFIG.149, a tissue thickness compensator52220can comprise a tubular element52280that comprises a permeable tubular lattice52292. In various embodiments, the sheet of material52224can comprise a bioabsorbable, biocompatible elastomeric polymer and can comprise a medicament, for example. Similar to at least one embodiment described herein, at least one tubular element52080can be configured to swell or expand, as illustrated inFIGS.150A-150D. For example, referring toFIG.150A, the tubular elements52080can be positioned intermediate the first and second sheet of material52024a,52024bin the tissue thickness compensator52020. When the tissue thickness compensator52020contacts tissue T, as illustrated inFIG.150B, the tissue thickness compensator52020can expand. In various embodiments, for example, the tubular elements52080can comprise a hydrophilic substance52099that expands when exposed to fluid in and/or on the tissue T. Further, the sheet of material52024and tubular elements52080can be permeable, as described herein, such that fluid from the tissue T can permeate the tissue thickness compensator52020thereby allowing the fluid to contact the hydrophilic substance52099within the tubular elements52080. As the tubular elements52080expand, the sheet of material52024surrounding the tubular elements52080can shift or adjust to accommodate the swollen tubular elements52080. Similar to various tissue thickness compensators discussed throughout the present disclosure, the expanded tissue thickness compensator52020can be deformed or compressed by an applied force, such as, for example, a compressive force applied by fired staples, as illustrated inFIG.150C. Further, the tissue thickness compensator52020can be sufficiently resilient such that it produces a springback force when deformed by the applied force and can subsequently rebound when the applied force is removed. Referring now toFIGS.150D and150E, the tissue thickness compensator52020can rebound to different configurations in different staple entrapment areas30039to appropriately accommodate the captured tissue T. Referring toFIGS.151-156, a tissue thickness compensator53020can comprise a plurality of vertically positioned tubular elements53080. In various embodiments, each tubular element53080can comprise a tubular axis that is substantially perpendicular to the top deck surface30011of the rigid support portion30010of the staple cartridge30000. Further, the first end of each tubular element53080can be positioned adjacent to the top deck surface30011, for example. Similar to at least one embodiment described herein, the tubular elements53080can be deformable and may comprise an elastomeric polymer, for example. In various embodiments, as illustrated inFIG.152, the tubular elements53080can be compressed when captured in a staple entrapment area30039with stapled tissue T. A tubular element53080can comprise an elastic material such that deformation of the tubular element53080generates a restoring force as the tubular element53080seeks to rebound from the deformed configuration. In some embodiments, deformation of the tubular element53080can be at least partially elastic and at least partially plastic. The tubular element53080can be configured to act as a spring under an applied force and, in various embodiments, can be configured not to buckle. In various embodiments, referring toFIG.153, the tubular elements53080can be substantially cylindrical. In some embodiments, referring toFIG.154, a tubular element53180can comprise a buckling region53112. The tubular element53180can be configured to buckle or deform at the buckling region53112when a compressive force is applied thereto. The tubular element53180can deform elastically and/or plastically and then be designed to buckle suddenly at the buckling region53112under a preselected buckling force. Referring primarily toFIG.155, a first tubular element53080can be positioned at a first end of a staple cavity30012and another tubular element53080can be positioned at a second end of the staple cavity30012. As illustrated inFIG.153, the tubular element53080can comprise a lumen53084extending therethrough. Referring again toFIG.152, when the staple30030is moved from the initial position to the fired position, each staple leg30032can be configured to pass through a lumen53084of each tubular element53080. In various other embodiments, referring primarily toFIG.156, vertically positioned tubular elements54080can be arranged in a tissue thickness compensator54020such that the tubular elements54080abut or contact each other. In other words, the tubular elements54080can be clustered or gathered together. In some embodiments, the tubular elements54080can be systematically arranged in the tissue thickness compensator54020; however, in other embodiments, the tubular elements54080can be randomly arranged. Referring again toFIGS.151,155, and156, the tissue thickness compensator53020can also comprise a sheet of material53024that holds or retains the tubular elements53080in the tissue thickness compensator53020. In various embodiments, the sheet of material53024can be positioned above and/or below the tubular elements53080and can securely retain each tubular element53080in the tissue thickness compensator53020. In various embodiments, the tissue thickness compensator53020can comprise a first and a second sheet of material53024. In various embodiments, the tubular elements53080can be positioned between the first and second sheets of material53024. Further, the sheet of material53024can be secured to the top deck surface30011of the rigid support portion of the staple cartridge30000such that the tissue thickness compensator53020is securely positioned in the end effector12. In other embodiments, a sheet of material53024can be secured to the anvil30060or otherwise retained in the end effector12. Similar to at least one embodiment described herein, the sheet of material53024can be sufficiently deformable such that the sheet of material53024deforms as springs55080within the tissue thickness compensator are deformed. Referring toFIGS.157and158, a tissue thickness compensator55020can comprise at least one spring55080that is sufficiently resilient such that it is capable of producing a springback force when deformed. Referring primarily toFIG.157, the tissue thickness compensator55020can comprise a plurality of springs55080, such as, for example, three rows of springs55080. The springs55080can be systematically and/or randomly arranged in the tissue thickness compensator55020. In various embodiments, the springs55080can comprise an elastomeric polymer, for example. In some embodiments, the shape of the springs55080can allow for deformation thereof. In various embodiments, the springs55080can be deformed from an initial configuration to a deformed configuration. For example, when a portion of the tissue thickness compensator55020is captured in a staple entrapment area30039, the springs55080in and/or around the staple entrapment area30039can be deformed. In various embodiments, the springs55080can buckle or collapse under a compressive force applied for a fired staple30030and the springs55080may generate a restoring force that is a function of the spring rate of the deformed spring55080and/or the amount the spring55080is deformed, for example. In some embodiments, the spring55080can act as a sponge under a compressive force applied by a fired staple30030. Further, the spring55080can comprise a compensation material, as described in greater detail throughout the present disclosure. The tissue thickness compensator55020can further comprise one or more sheets of material55024that hold or retain at least one spring55080in the tissue thickness compensator55020. In various embodiments, the sheets of material55024can be positioned above and/or below the springs55080and can securely retain the springs55080in the tissue thickness compensator55020. In at least one embodiment, the tissue thickness compensator55020can comprise a first sheet of material55024aand a second sheet of material55024b. In various embodiments, the tubular elements52080can be positioned between the first and second sheets of material55024a,55024b. Referring primarily toFIG.158, in various embodiments, the tissue thickness compensator55020can further comprise a third sheet of material55024cpositioned adjacent to either the first or second sheet of material55024a,55024b. In various embodiments, at least one sheet of material55024can be secured to the top deck surface30011of the rigid support portion of the staple cartridge30000, such that the tissue thickness compensator55020is securely positioned in the end effector12. In other embodiments, at least one sheet of material55024can be secured to the anvil30060or otherwise retained in the end effector12. Referring now toFIG.158, when a staple30030is fired from the staple cartridge30000(FIG.156), the staple30030can engage the tissue thickness compensator55020. In various embodiments, the fired staple30030can capture tissue T and a portion of the tissue thickness compensator55020in the staple entrapment area30039. The springs55080can be deformable such that the tissue thickness compensator55020compresses when captured by a fired staple30030. In some embodiments, the springs55080can be positioned between fired staples30030in the tissue thickness compensator55020. In other embodiments, at least one spring55080can be captured within the staple entrapment area30039. Referring toFIG.159, a tissue thickness compensator60020can comprise at least two compensation layers60022. In various embodiments, the tissue thickness compensator60020can comprise a plurality of compensation layers60022which can be stacked on top of each other, positioned side-by-side, or a combination thereof. As described in greater detail herein, the compensation layers60022of the tissue thickness compensator60020can comprise different geometric and/or material properties, for example. Furthermore, as described in greater detail herein, pockets and/or channels can exist between adjacently stacked compensation layers60022. For example, a tissue thickness compensator62020can comprise six compensation layers62022a,62022b,62022c,62022d,62022e,62022f, which can be adjacently stacked on top of each other (FIG.174). Referring toFIGS.160,161, and163-168, a tissue thickness compensator can comprise a first compensation layer60122aand a second compensation layer60122b. In various embodiments, the first compensation layer60122acan be adjacently stacked on top of the second compensation layer60122b. In at least one embodiment, adjacently stacked compensation layers60122can be separated by a separation gap or pocket60132. Referring primarily toFIG.160, a tissue thickness compensator60120can also comprise at least one cantilever beam or support60124positioned between the first and second compensation layers60122a,60122b. In various embodiments, the support60124can be configured to position the first compensation layer60122arelative to the second compensation layer60122bsuch that compensation layers60122are separated by the separation gap60132. As described in greater detail herein, deformation of the support60124and/or the compensation layers60122a,60122b, for example, can reduce the separation gap60132. The support beam of a tissue thickness compensator can comprise various geometries and dimensions. For example, the support beam can be a simple I-beam, a centered, single-bend support beam60124(FIG.160), an off-centered, single-bend support beam60224(FIG.161), an elliptical support beam60324(FIG.163), a multi-bend support beam60424(FIG.164), and/or a symmetrical, dual-cantilevered support beam60524(FIG.165). Furthermore, referring now toFIGS.160,166, and167, a support beam60624can be thinner than at least one compensation layer60122(FIG.166), a support beam60724can be thicker than at least one compensation layer60122(FIG.167), and/or a support beam60124can be substantially the same thickness as at least one compensation layer60122(FIG.160), for example. The material, geometry and/or dimensions of the support beam60124, for example, can affect the deformability and springback resiliency of the tissue thickness compensator60120. Referring still toFIG.160, the compensation layers60122and support beam60124of the tissue thickness compensator60120can comprise different materials, such as, for example, structural material, biological material, and/or electrical material, for example. For example, in various embodiments, at least one compensation layer60122can comprise a polymeric composition. The polymeric composition can comprise an at least partially elastic material such that deformation of the compensation layer60122and/or the support beam60124can generate a springback force. The polymeric composition of the compensation layer60122can comprise non-absorbable polymers, absorbable polymers, or combinations thereof. In some embodiments, the absorbable polymers can include bioabsorbable, biocompatible elastomeric polymers, for example. Furthermore, the polymeric composition of the compensation layer60122can comprise synthetic polymers, non-synthetic polymers, or combinations thereof. Examples of synthetic polymers include, but are not limited to, polyglycolic acid (PGA), poly(lactic acid) (PLA), polycaprolactone (PCL), polydioxanone (PDO), and copolymers thereof. Examples of non-synthetic polymers include, but are not limited to, polysaccharides, glycoprotein, elastin, proteoglycan, gelatin, collagen, and oxidized regenerated cellulose (ORC). In various embodiments, similar to the polymeric compositions in embodiments described herein, the polymeric composition of the compensation layers60122can include varied amounts of absorbable polymers, non-absorbable polymers, synthetic polymers, and non-synthetic polymers, for example, by weight percentage. In various embodiments, each compensation layer60022in the tissue thickness compensator60120can comprise a different polymeric composition or, in various other embodiments, at least two compensation layers60122can comprise the same polymeric composition. Referring again toFIG.159, in various embodiments, at least one compensation layer60022can comprise a therapeutic agent60098such as a medicament or pharmaceutically active agent, for example. The compensation layer60022can release a therapeutically effective amount of the therapeutic agent60098. In various embodiments, the therapeutic agent60098can be released as the compensation layer60022is absorbed. Examples of therapeutic agents60098can include, but are not limited to, haemostatic agents and drugs, such as, for example, fibrin, thrombin, and/or oxidized regenerated cellulose (ORC), anti-inflammatory drugs such as, for example, diclofenac, aspirin, naproxen, sulindac, and/or hydrocortisone antibiotic and antimicrobial drugs or agents such as, for example, triclosan, ionic silver, ampicillin, gentamicin, polymyxin B, and/or chloramphenicol, and/or anticancer agents such as, for example, cisplatin, mitomycin, and/or adriamycin. In some embodiments, the therapeutic agent60098can comprise a biologic, such as a stem cell, for example. In various embodiments, each compensation layer60022in a tissue thickness compensator60020can comprise a different therapeutic agent60098or, in various other embodiments, at least two compensation layers60022can comprise the same therapeutic agent60098. In at least one embodiment, a compensation layer60022comprising a therapeutic agent60098, such as a biologic, for example, can be encased between two structural compensation layers60022comprising a polymeric composition, such as, for example, polyglycolic acid (PGA) foam, for example. In various embodiments, a compensation layer60022can also comprise an electrically conductive material, such as, for example, copper. In various embodiments, referring again toFIG.174, the compensation layers62022in the tissue thickness compensator62020can have different geometries. When layers62022are adjacently positioned in the tissue thickness compensator62020, the compensation layers62022can form at least one three-dimensional conduit62032between the layers62022. For example, when a second compensation layer62022bcomprising a channel is positioned above a substantially flat third compensation layer62022c, the channel and flat surface of the third compensation layer62022ccan define a three-dimensional conduit62032atherebetween. Similarly, for example, when a fifth compensation layer62022ecomprising a channel is positioned below a fourth compensation layer62022dcomprising a corresponding channel, the channels can form a three-dimensional conduit62032bdefined by the channels in the adjacently stacked compensation layers62022d,62022e. In various embodiments, the conduits62032can direct therapeutic agents and/or bodily fluids as the fluids flow through the tissue thickness compensator62020. In various embodiments, referring toFIG.170, a tissue thickness compensator61020can comprise compensation layers61022, such as layers60122aand21022b, configured to receive staples30030deployed from the staple cartridge20000(FIG.169). As a staple30030is moved from an initial position to a fired position, the geometry of at least one compensation layer61022can guide the staple legs30032to the fired position. In various embodiments, at least one compensation layer61022can comprise apertures61030extending therethrough, wherein the apertures61030can be arranged to receive the staple legs30032of deployed staples30030when the staples30030are fired from the staple cartridge20000(FIG.169), as described in greater detail herein. In various other embodiments, referring again toFIG.174, staple legs30032can pierce through at least one compensation layer, such as compensation layer62022f, for example, and can be received through apertures62030in at least one compensation layer, such as, for example, compensation layer62022a. Referring primarily toFIG.170, the tissue thickness compensator60120can comprise at least one support tab61026on one of the compensation layers61022a,61022b. The support tab61026can protrude into the separation gap61032defined between adjacent compensation layers, such as the gap61032between the first compensation layer61020aand second compensation layer61020b. In various embodiments, the support tab61026can protrude from a longitudinal side of a first compensation layer61022a. Further, the support tab61026can extend along the length of the longitudinal side or only along a portion thereof. In various embodiments, at least one support tab61026can protrude from two longitudinal sides of the compensation layer61022a,61022b. Further, adjacently positioned compensation layers61022a,61022bcan comprise corresponding support tabs60126, such that the support tab60126that extends from the first compensation layer60122acan at least partially align with the support tab60126that extends from the second compensation layer60122b. In at least one embodiment, referring again toFIG.168, a tissue thickness compensator60820can comprise a limiter plate60828between adjacent compensation layers60122a,60122b. The limiter plate60828can be positioned in the gap60132defined between the first compensation layer60122aand the second compensation layer60122b, for example. As described in greater detail herein, support tab(s)61026and/or limiter plate(s)60828can control the deformation and/or deflection of a support60124and/or the compensation layers60122a,60122b. As described herein, in various embodiments, the compensation layers60022of the tissue thickness compensator60020can comprise different materials, geometries and/or dimensions. Such tissue thickness compensators60020can be assembled by a variety of manufacturing techniques. Referring primarily toFIG.159, the tissue thickness compensator60022can be manufactured by lithographic, stereolithographic (SLA), or silk screening processes. For example, a stereolithographic manufacturing process can create a tissue thickness compensator60020in which each compensation layer60022comprises different materials and/or geometric features. For example, an ultraviolet light in a stereolithography machine can draw the geometry of a first compensation layer60022, such that the first compensation layer60022comprising a first material, geometry and/or dimensions is cured by the ultraviolet light. The ultraviolet light can subsequently draw the geometry of a second compensation layer60022, such that the second compensation layer60022comprising a second material, geometry and/or dimensions is cured by the ultraviolet light. In various embodiments, a stereolithography machine can draw compensation layers60022on top of each other, side-by-side, or a combination thereof. Further, the compensation layers60022can be drawn such that pockets60132exist between adjacent compensation layers60022. Because a stereolithography machine can create very thin layers having unique geometries, a tissue thickness compensator60020manufactured by a stereolithographic process can comprise a very complex three-dimensional geometry. In various embodiments, referring toFIG.169, the tissue thickness compensator60920can be positioned in the end effector12of a surgical instrument10(FIG.1). The tissue thickness compensator60920can be positioned relative to the staple cartridge20000of the end effector12. For example, the tissue thickness compensator60920can be releasably secured to the staple cartridge20000. In at least one embodiment, at least one compensation layer60922of the tissue thickness compensator60920can be positioned adjacent to the top deck surface20011(FIG.79) of the staple cartridge20000. For example, a second compensation layer60922bcan be secured to the top deck surface20011by an adhesive or by a wrap, similar to at least one of the wraps described herein (FIG.16). In various embodiments, the tissue thickness compensator60920can be integral to the staple cartridge20000such that the staple cartridge20000and the tissue thickness compensator60920are formed as a single unit construction. For example, the staple cartridge20000can comprise a first body portion, such as the rigid support portion20010(FIG.79), and a second body portion, such the as tissue thickness compensator60920. Still referring toFIG.169, the tissue thickness compensator60920can comprise a first compensator portion60920aand a second compensator portion60920b. The first compensator portion60920acan be positioned on a first longitudinal side of the staple cartridge20000and the second compensator portion60920bcan be positioned on a second longitudinal side of the staple cartridge20000. In various embodiments, when the tissue thickness compensator60920is positioned relative to the staple cartridge20000, the longitudinal slot20015(FIG.78) in the rigid support portion20010(FIG.78) can extend between the first compensator portion60920aand the second compensator portion60920b. When the cutting element20052on the staple-firing sled20050(FIG.78) translates through the end effector12, the cutting element20052can pass through the longitudinal slot20015between the first compensator portion60920aand the second compensator portion60920bwithout severing a portion of the tissue thickness compensator60920, for example. In other embodiments, the cutting element20052can be configured to sever a portion of the tissue thickness compensator60920. In various embodiments, referring now toFIG.162, a tissue thickness compensator63020can be configured to fit in the end effector12′ of a circular surgical instrument. In various embodiments, the tissue thickness compensator62030can comprise a circular first compensation layer63022aand a circular second compensation layer63022b. The second compensation layer63022bcan be positioned on a circular top deck surface20011′ of a circular staple cartridge20000′, wherein the second compensation layer63022bcan comprise a geometry that corresponds to the geometry of the deck surface20011′. For example, the deck surface20011′ can comprise a stepped portion and the second compensation layer63022bcan comprise a corresponding stepped portion. Similar to various embodiments described herein, the tissue thickness compensator can further comprise at least one support63024and/or support tabs63026, for example, extending around the tissue thickness compensator63020. Referring again toFIG.170, fired staples30030can be configured to engage the tissue thickness compensator60920. As described throughout the present disclosure, a fired staple30030can capture a portion of the tissue thickness compensator60920and tissue T and apply a compressive force to the tissue thickness compensator60920. Further, referring primarily toFIGS.171-173, the tissue thickness compensator60920can be deformable. In various embodiments, as described herein, a first compensation layer60920acan be separated from a second compensation layer60920bby a separation gap60932. Referring toFIG.171, prior to compression of the tissue thickness compensator60920, the gap60932can comprise a first distance. When a compressive force A is applied to the tissue thickness compensator60920and tissue T, for example, by a fired staple30030(FIG.170), the support60924can be configured to deform. Referring now toFIG.172, the single-bend support beam60924can bend under the compressive force A such that the separation gap60932between the first compensation layer60920aand the second compensation layer60920bis reduced to a second distance. Referring primarily toFIG.173, the first and second compensation layers60922a,60922bcan also deform under the compressive force A. In various embodiments, the support tabs60926can control deformation of the compensation layers60920. For example, the support tabs60926can prevent excessive bending of the compensation layers60920by supporting the longitudinal sides of the compensation layer60920when they come into contact with one another. The support tabs60926can also be configured to bend or bow under the compressive force A. Additionally or alternatively, the limiter plate60128(FIG.168) described in greater detail herein, can limit the deformation of the compensation layers60920when the compensation layers60920and/or support tabs60926contact the limiter plate60128. Furthermore, similar to various tissue thickness compensators described herein, tissue thickness compensator60920can generate a springback or restoring force when deformed. The restoring force generated by the deformed tissue thickness compensator can at least depend on the orientation, dimensions, material, and/or geometry of the tissue thickness compensator60920, as well as the amount of the tissue thickness compensator60920that is deformed by the applied force. Furthermore, in various embodiments, at least a portion of the tissue thickness compensator60920can be resilient such that the tissue thickness compensator60920generates a spring load or restoring force when deformed by a fired staple30030. In at least one embodiment, the support60924can comprise an elastic material and/or at least one compensation layer60922can comprise an elastic material such that the tissue thickness compensator60920is resilient. In various embodiments, referring now toFIG.175, an end effector of a surgical stapling instrument can comprise a first jaw and a second jaw, wherein at least one of the first jaw and the second jaw can be configured to be moved relative to the other. In certain embodiments, the end effector can comprise a first jaw including a staple cartridge channel19070and a second jaw including an anvil19060, wherein the anvil19060can be pivoted toward and/or away from the staple cartridge channel19070, for example. The staple cartridge channel19070can be configured to receive a staple cartridge19000, for example, which, in at least one embodiment, can be removably retained within the staple cartridge channel19070. In various embodiments, the staple cartridge19000can comprise a cartridge body19010and a tissue thickness compensator19020wherein, in at least one embodiment, the tissue thickness compensator19020can be removably attached to the cartridge body19010. Similar to other embodiments described herein, referring now toFIG.176, the cartridge body19010can comprise a plurality of staple cavities19012and a staple19030positioned within each staple cavity19012. Also similar to other embodiments described herein, the staples19030can be supported by staple drivers19040positioned within the cartridge body19010wherein a sled and/or firing member, for example, can be advanced through the staple cartridge19000to lift the staple drivers19040upwardly within the staple cavities19012, as illustrated inFIG.177, and eject the staples19030from the staple cavities19012. In various embodiments, referring primarily toFIGS.175and176, the tissue thickness compensator19020can comprise resilient members19022and a vessel19024encapsulating the resilient members19022. In at least one embodiment, the vessel19024can be sealed and can define a cavity containing an inner atmosphere having a pressure which is different than the surrounding atmospheric pressure. In certain embodiments, the pressure of the inner atmosphere can be greater than the pressure of the surrounding atmosphere while, in other embodiments, the pressure of the inner atmosphere can be less than the pressure of the surrounding atmosphere. In the embodiments in which the vessel19024contains a pressure less than the pressure of the surrounding atmosphere, the sidewall of the vessel19024can enclose a vacuum. In such embodiments, the vacuum can cause the vessel19024to distort, collapse, and/or flatten wherein the resilient members19022positioned within the vessel19024can be resiliently compressed within the vessel19024. When a vacuum is drawn on the vessel19024, the resilient members19022can deflect or deform downwardly and can be held in position by the sidewalls of the vessel19024in a compressed, or vacuum-packed, state. Resilient member19022and vessel19024are comprised of biocompatible materials. In various embodiments, resilient member19022and/or vessel19024can be comprised of bioabsorbable materials such as PLLA, PGA, and/or PCL, for example. In certain embodiments, resilient member19022can be comprised of a resilient material. Resilient member19022can also comprise structural resilience. For example, resilient member19022can be in the form of a hollow tube. Further to the above, the tissue thickness compensator19020can be positioned against or adjacent to the deck surface19011of the cartridge body19010. When the staples19030are at least partially fired, referring now toFIG.177, the legs of the staples19030can puncture or rupture the vessel19024. In certain embodiments, the vessel19024can comprise a central portion19026which can be positioned over a cutting slot19016of the cartridge body19010such that, when a cutting member19080is advanced to incise tissue T positioned between the staple cartridge19000and the anvil19060, the cutting member19080can also incise the central portion19026of the vessel19024thereby puncturing or rupturing the vessel19024. In either event, once the vessel19024has been ruptured, the inner atmosphere within the vessel19024can equalize with the atmosphere surrounding the tissue thickness compensator19020and allow the resilient members19022to resiliently expand to regain, or at least partially regain, their undistorted and/or unflattened configuration. In such circumstances, the resilient members19022can apply a biasing force to the tissue T captured within the deformed staples19020. More specifically, after being deformed by the forming surfaces of pockets19062defined in the anvil19060, the legs of the staples19030can capture tissue T and at least a portion of a resilient member19022within the staples19030such that, when the vessel19024ruptures, the tissue thickness compensator19020can compensate for the thickness of the tissue T captured within the staples19030. For instance, when the tissue T captured within a staple19030is thinner, a resilient member19022captured within that staple19030can expand to fill gaps within the staple19030and apply a sufficient compression force to the tissue T. Correspondingly, when the tissue T captured within a staple19030is thicker, a resilient member19022captured within that staple19030can remain compressed to make room for the thicker tissue within the staple19030and, likewise, apply a sufficient compression force to the tissue T. When the vessel19024is punctured, as outlined above, the resilient members19022can expand in an attempt to resiliently return to their original configuration. In certain circumstances, the portion of resilient members19022that have been captured within the staples19030may not be able to return to their original undistorted shape. In such circumstances, the resilient members19022can comprise a spring which can apply a compression force to the tissue T captured within the staples19030. In various embodiments, a resilient member19022can emulate a linear spring wherein the compression force applied by the resilient member19022is linearly proportional to the amount, or distance, in which the resilient member19022remains deflected within the staple19030. In certain other embodiments, a resilient member19022can emulate a non-linear spring wherein the compression force applied by the resilient member19022is not linearly proportional to the amount, or distance, in which the resilient member19022remains deflected within the staple19030. In various embodiments, referring primarily toFIGS.178and179, a staple cartridge19200can comprise a tissue thickness compensator19220which can comprise one or more sealed vessels19222therein. In at least one embodiment, each of the vessels19222can be sealed and can contain an inner atmosphere. In certain embodiments, the pressure of the inner atmosphere within a sealed vessel19222can exceed atmospheric pressure while, in certain other embodiments, the pressure of the inner atmosphere within a sealed vessel19222can be below atmospheric pressure. In embodiments where the pressure of the inner atmosphere within a vessel19222is below atmospheric pressure, the vessel19222can be described as containing a vacuum. In various embodiments, one or more of the vessels19222can be wrapped or contained in an outer shroud, container, wrap, and/or film19224, for example, wherein the tissue thickness compensator19220can be positioned above a deck surface19011of the cartridge body19010. In certain embodiments, each vessel19222can be manufactured from a tube having a circular, or an at least substantially circular, cross-section, for example, having a closed end and an open end. A vacuum can be drawn on the open end of the tube and, when a sufficient vacuum has been reached within the tube, the open end can be closed and sealed. In at least one such embodiment, the tube can be comprised of a polymeric material, for example, wherein the open end of the tube can be heat staked in order to close and seal the same. In any event, the vacuum within each vessel19222can pull the sidewalls of the tube inwardly and resiliently distort and/or flatten the tube. The vessels19222are illustrated in an at least partially flattened state inFIG.179. When the staples19030are in their unfired position, as illustrated inFIG.179, the tips of the staples19030can be positioned below the tissue thickness compensator19220. In at least one such embodiment, the staples19030can be positioned within their respective staple cavities19012such that the staples19030do not contact the vessels19222until the staples19030are moved from the unfired positions, illustrated inFIG.179, to their fired positions, illustrated inFIG.180. In certain embodiments, the wrap19224of the tissue thickness compensator19220can protect the vessels19220from being prematurely punctured by the staples19030. When the staples19030are at least partially fired, referring now toFIG.180, the legs of the staples19030can puncture or rupture the vessels19222. In such circumstances, the inner atmospheres within the vessels19222can equalize with the atmosphere surrounding the vessels19222and resiliently expand to regain, or at least partially regain, their undistorted and/or unflattened configuration. In such circumstances, the punctured vessels19222can apply a biasing force to the tissue captured within the deformed staples19030. More specifically, after being deformed by the forming surfaces of pockets19062defined in the anvil19060, the legs of the staples19030can capture tissue T and at least a portion of a vessel19222within the staples19030such that, when the vessels19222rupture, the vessels19222can compensate for the thickness of the tissue T captured within the staples19030. For instance, when the tissue T captured within a staple19030is thinner, a vessel19222captured within that staple19030can expand to fill gaps within the staple19030and, concurrently, apply a sufficient compression force to the tissue T. Correspondingly, when the tissue T captured within a staple19030is thicker, a vessel19222captured within that staple19030can remain compressed to make room for the thicker tissue within the staple19030and, concurrently, apply a sufficient compression force to the tissue T. When the vessels19222are punctured, as outlined above, the vessels19222can expand in an attempt to resiliently return to their original configuration. The portion of vessels19222that have captured within the staples19030may not be able to return to their original undistorted shape. In such circumstances, the vessel19222can comprise a spring which can apply a compression force to the tissue T captured within the staples19030. In various embodiments, a vessel19222can emulate a linear spring wherein the compression force applied by the vessel19222is linearly proportional to the amount, or distance, in which the vessel19222remains deflected within the staple19030. In certain other embodiments, a vessel19222can emulate a non-linear spring wherein the compression force applied by the vessel19222is not linearly proportional to the amount, or distance, in which the vessel19222remains deflected within the staple19030. In various embodiments, the vessels19222can be hollow and, in at least one embodiment, empty when they are in their sealed configuration. In certain other embodiments, each of the vessels19222can define a cavity and can further include at least one medicament contained therein. In at least some embodiments, the vessels19222can be comprised of at least one medicament which can be released and/or bioabsorbed, for example. In various embodiments, the vessels19222of the tissue thickness compensator19220can be arranged in any suitable manner. As illustrated inFIG.178, the staple cavities19012defined in the cartridge body19010, and the staples19030positioned in the staple cavities19012, can be arranged in rows. In at least the illustrated embodiment, the staple cavities19012can be arranged in six longitudinal, linear rows, for example; however, any suitable arrangement of staple cavities19012could be utilized. As also illustrated inFIG.178, the tissue thickness compensator19220can comprise six vessels19222wherein each of the vessels19222can be aligned with, or positioned over, a row of staple cavities19012. In at least one embodiment, each of the staples19030within a row of staple cavities19012can be configured to puncture the same vessel19222. In certain situations, some of the staple legs of the staples19030may not puncture the vessel19222positioned thereover; however, in embodiments where the vessel19222defines a continuous internal cavity, for example, the cavity can be sufficiently punctured by at least one of the staples19030in order to allow the pressure of the internal cavity atmosphere to equalize with the atmospheric pressure surrounding the vessel19222. In various embodiments, referring now toFIG.185, a tissue thickness compensator can comprise a vessel, such as vessel19222′, for example, which can extend in a direction which is transverse to a line of staples19030. In at least one such embodiment, a vessel19222′ can extend across multiple staple rows. In certain embodiments, referring now toFIG.186, a tissue thickness compensator19220″ can comprise a plurality of vessels19222″ which extend in a direction which is perpendicular, or at least substantially perpendicular, to a line of staples19030. In at least one such embodiment, some of the vessels19222″ may be punctured by the staples19030while others may not be punctured by the staples19030. In at least one embodiment, the vessels19222″ can extend across or through a cutting path in which a cutting member could transect and rupture the vessels19222″, for example. In various embodiments, as described above, a tissue thickness compensator, such as tissue thickness compensator19220, for example, can comprise a plurality of sealed vessels, such as vessels19222, for example. As also described above, each of the sealed vessels19222can comprise a separate internal atmosphere. In certain embodiments, the vessels19222can have different internal pressures. In at least one embodiment, for example, a first vessel19222can comprise an internal vacuum having a first pressure and a second vessel19222can comprise an internal vacuum having a second, different pressure, for example. In at least one such embodiment, the amount of distortion or flattening of a vessel19222can be a function of the vacuum pressure of the internal atmosphere contained therein. For instance, a vessel19222having a greater vacuum can be distorted or flattened a greater amount as compared to a vessel19222having a smaller vacuum. In certain embodiments, the cavity of a vessel can be segmented into two or more separate, sealed cavities wherein each separate, sealed cavity can comprise a separate internal atmosphere. In at least one such embodiment, some of the staples within a staple row can be configured and arranged to puncture a first cavity defined in the vessel while other staples within the staple row can be configured and arranged to puncture a second cavity defined in the vessel, for example. In such embodiments, especially in embodiments in which the staples in a staple row are sequentially fired from one end of the staple row to the other, as described above, one of the cavities can remain intact and can maintain its internal atmosphere when another cavity is ruptured. In certain embodiments, the first cavity can have an inner atmosphere having a first vacuum pressure and the second cavity can have an inner atmosphere having a second, different vacuum pressure, for example. In various embodiments, a cavity that remains intact can maintain its inner pressure until the vessel is bioabsorbed thereby creating a timed pressure release. In various embodiments, referring now toFIGS.181and182, a tissue thickness compensator, such as tissue thickness compensator19120, for example, can be attached to an anvil19160. Similar to the above, the tissue thickness compensator19120can comprise a vessel19124and a plurality of resilient members19122positioned therein. Also similar to the above, the vessel19124can define a cavity containing an inner atmosphere having a pressure which is less than or greater than the pressure of the atmosphere surrounding the tissue thickness compensator19120. In embodiments where the inner atmosphere within the vessel19124comprises a vacuum, the vessel19124and the resilient members19122positioned therein can be distorted, collapsed, and/or flattened by the difference in pressure between the vacuum in the vessel19124and the atmospheric pressure outside of the vessel19124. In use, the anvil19160can be moved into a closed position in which it is positioned opposite a staple cartridge19100and in which a tissue engaging surface19121on the vessel19124can engage the tissue T positioned intermediate the tissue thickness compensator19120and a staple cartridge19100. In use, the firing member19080can be advanced distally to fire the staples19030, as described above, and, at the same time, incise the tissue T. In at least one embodiment, the tissue thickness compensator19120can further comprise an intermediate portion19126which can be aligned with a cutting slot defined in the anvil19160wherein, when the firing member19080is advanced distally through the tissue thickness compensator19120, the firing member19080can puncture or rupture the vessel19124. Also, similar to the above, the firing member19080can lift the staple drivers19040upwardly and fire the staples19030such that the staples19030can contact the anvil19160and be deformed into their deformed configuration, as illustrated inFIG.183. When the staples19030are fired, the staples19030can pierce the tissue T and then pierce or rupture the vessel19124such that the resilient members19122positioned within the vessel19124can at least partially expand, as outlined above. In various embodiments, further to the above, a tissue thickness compensator can be comprised of a biocompatible material. The biocompatible material, such as, a foam, may comprise tackifiers, surfactants, fillers, cross-linkers, pigments, dyes, antioxidants and other stabilizers and/or combinations thereof to provide desired properties to the material. In certain embodiments, a biocompatible foam may comprise a surfactant. The surfactant may be applied to the surface of the material and/or dispersed within the material. Without wishing to be bound to any particular theory, the surfactant applied to the biocompatible material may reduce the surface tension of the fluids contacting the material. For example, the surfactant may reduce the surface tension of water contacting the material to accelerate the penetration of water into the material. In various embodiments, the water may act as a catalyst. The surfactant may increase the hydrophilicity of the material. In various embodiments, the surfactant may comprise an anionic surfactant, a cationic surfactant, and/or a non-ionic surfactant. Examples surfactants include, but are not limited to polyacrylic acid, methalose, methyl cellulose, ethyl cellulose, propyl cellulose, hydroxy ethyl cellulose, carboxy methyl cellulose, polyoxyethylene cetyl ether, polyoxyethylene lauryl ether, polyoxyethylene octyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene oleyl ether, polyoxyethylene sorbitan monolaurate, polyoxyethylene stearyl ether, polyoxyethylene nonylphenyl ether, dialkylphenoxy poly(ethyleneoxy) ethanol, and polyoxamers, and combinations thereof. In at least one embodiment, the surfactant may comprise a copolymer of polyethylene glycol and polypropylene glycol. In at least one embodiment, the surfactant may comprise a phospholipid surfactant. The phospholipid surfactant may provide antibacterial stabilizing properties and/or disperse other materials in the biocompatible material. In various embodiments, the tissue thickness compensator may comprise at least one medicament. The tissue thickness compensator may comprise one or more of the natural materials, non-synthetic materials, and/or synthetic materials described herein. In certain embodiments, the tissue thickness compensator may comprise a biocompatible foam comprising gelatin, collagen, hyaluronic acid, oxidized regenerated cellulose, polyglycolic acid, polycaprolactone, polyactic acid, polydioxanone, polyhydroxyalkanoate, poliglecaprone, and combinations thereof. In certain embodiments, the tissue thickness compensator may comprise a film comprising the at least one medicament. In certain embodiments, the tissue thickness compensator may comprise a biodegradable film comprising the at least one medicament. In certain embodiments, the medicament may comprise a liquid, gel, and/or powder. In various embodiments, the medicaments may comprise anticancer agents, such as, for example, cisplatin, mitomycin, and/or adriamycin. In various embodiments, the tissue thickness compensator may comprise a biodegradable material to provide controlled elution of the at least one medicament as the biodegradable material degrades. In various embodiments, the biodegradable material may degrade may decompose, or loses structural integrity, when the biodegradable material contacts an activator, such as, for example an activator fluid. In various embodiments, the activator fluid may comprise saline or any other electrolyte solution, for example. The biodegradable material may contact the activator fluid by conventional techniques, including, but not limited to spraying, dipping, and/or brushing. In use, for example, a surgeon may dip an end effector and/or a staple cartridge comprising the tissue thickness compensator comprising the at least one medicament into an activator fluid comprising a salt solution, such as sodium chloride, calcium chloride, and/or potassium chloride. The tissue thickness compensator may release the medicament as the tissue thickness compensator degrades. In certain embodiments, the elution of the medicament from the tissue thickness compensator may be characterized by a rapid initial elution rate and a slower sustained elution rate. In various embodiments, a tissue thickness compensator, for example, can be comprised of a biocompatible material which may comprise an oxidizing agent. In various embodiments, the oxidizing agent may an organic peroxide and/or an inorganic peroxide. Examples of oxidizing agents may include, but are not limited to, hydrogen peroxide, urea peroxide, calcium peroxide, and magnesium peroxide, and sodium percarbonate. In various embodiments, the oxidizing agent may comprise peroxygen-based oxidizing agents and hypohalite-based oxidizing agents, such as, for example, hydrogen peroxide, hypochlorous acid, hypochlorites, hypocodites, and percarbonates. In various embodiments, the oxidizing agent may comprise alkali metal chlorites, hypochlorites and perborates, such as, for example, sodium chlorite, sodium hypochlorite and sodium perborate. In certain embodiments, the oxidizing agent may comprise vanadate. In certain embodiments, the oxidizing agent may comprise ascorbic acid. In certain embodiments, the oxidizing agent may comprise an active oxygen generator. In various embodiments, a tissue scaffold may comprise the biocompatible material comprising an oxidizing agent. In various embodiments, the biocompatible material may comprise a liquid, gel, and/or powder. In certain embodiments, the oxidizing agent may comprise microparticles and/or nanoparticles, for example. For example, the oxidizing agent may be milled into microparticles and/or nanoparticles. In certain embodiments, the oxidizing agent may be incorporated into the biocompatible material by suspending the oxidizing agent in a polymer solution. In certain embodiments, the oxidizing agent may be incorporated into the biocompatible material during the lyophylization process. After lyophylization, the oxidizing agent may be attached to the cell walls of the biocompatible material to interact with the tissue upon contact. In various embodiments, the oxidizing agent may not be chemically bonded to the biocompatible material. In at least one embodiment, a percarbonate dry power may be embedded within a biocompatible foam to provide a prolonged biological effect by the slow release of oxygen. In at least one embodiment, a percarbonate dry power may be embedded within a polymeric fiber in a non-woven structure to provide a prolonged biological effect by the slow release of oxygen. In various embodiments, the biocompatible material may comprise an oxidizing agent and a medicament, such as, for example, doxycycline and ascorbic acid. In various embodiments, the biocompatible material may comprise a rapid release oxidizing agent and/or a slower sustained release oxidizing agent. In certain embodiments, the elution of the oxidizing agent from the biocompatible material may be characterized by a rapid initial elution rate and a slower sustained elution rate. In various embodiments, the oxidizing agent may generate oxygen when the oxidizing agent contacts bodily fluid, such as, for example, water. Examples of bodily fluids may include, but are not limited to, blood, plasma, peritoneal fluid, cerebral spinal fluid, urine, lymph fluid, synovial fluid, vitreous fluid, saliva, gastrointestinal luminal contents, and/or bile. Without wishing to be bound to any particular theory, the oxidizing agent may reduce cell death, enhance tissue viability and/or maintain the mechanical strength of the tissue to tissue that may be damaged during cutting and/or stapling. In various embodiments, the biocompatible material may comprise at least one microparticle and/or nanoparticle. The biocompatible material may comprise one or more of the natural materials, non-synthetic materials, and synthetic materials described herein. In various embodiments, the biocompatible material may comprise particles having a mean diameter of about 10 nm to about 100 nm and/or about 10 μm to about 100 μm, such as, for example, 45-50 nm and/or 45-50 μm. In various embodiments, the biocompatible material may comprise biocompatible foam comprising at least one microparticle and/or nanoparticle embedded therein. The microparticle and/or nanoparticle may not be chemically bonded to the biocompatible material. The microparticle and/or nanoparticle may provide controlled release of the medicament. In certain embodiments, the microparticle and/or nanoparticle may comprise at least one medicament. In certain embodiments, the microparticle and/or nanoparticle may comprise a hemostatic agent, an anti-microbial agent, and/or an oxidizing agent, for example. In certain embodiments, the tissue thickness compensator may comprise a biocompatible foam comprising an hemostatic agent comprising oxidized regenerated cellulose, an anti-microbial agent comprising doxycline and/or Gentamicin, and/or an oxidizing agent comprising a percarbant. In various embodiments, the microparticle and/or nanoparticle may provide controlled release of the medicament up to three days, for example. In various embodiments, the microparticle and/or nanoparticle may be embedded in the biocompatible material during a manufacturing process. For example, a biocompatible polymer, such as, for example, a PGA/PCL, may contact a solvent, such as, for example, dioxane to form a mixture. The biocompatible polymer may be ground to form particles. Dry particles, with or without ORC particles, may be contacted with the mixture to form a suspension. The suspension may be lyophilized to form a biocompatible foam comprising PGA/PCL having dry particles and/or ORC particles embedded therein. In various embodiments, the tissue thickness compensators or layers disclosed herein can be comprised of an absorbable polymer, for example. In certain embodiments, a tissue thickness compensator can be comprised of foam, film, fibrous woven, fibrous non-woven PGA, PGA/PCL (Poly(glycolic acid-co-caprolactone)), PLA/PCL (Poly(lactic acid-co-polycaprolactone)), PLLA/PCL, PGA/TMC (Poly(glycolic acid-co-trimethylene carbonate)), PDS, PEPBO or other absorbable polyurethane, polyester, polycarbonate, Polyorthoesters, Polyanhydrides, Polyesteramides, and/or Polyoxaesters, for example. In various embodiments, a tissue thickness compensator can be comprised of PGA/PLA (Poly(glycolic acid-co-lactic acid)) and/or PDS/PLA (Poly(p-dioxanone-co-lactic acid)), for example. In various embodiments, a tissue thickness compensator can be comprised of an organic material, for example. In certain embodiments, a tissue thickness compensator can be comprised of Carboxymethyl Cellulose, Sodium Alginate, Cross-linked Hyaluronic Acid, and/or Oxidized regenerated cellulose, for example. In various embodiments, a tissue thickness compensator can comprise a durometer in the 3-7 Shore A (30-50 Shore 00) ranges with a maximum stiffness of 15 Shore A (65 Shore 00), for example. In certain embodiments, a tissue thickness compensator can undergo 40% compression under 3 lbf load, 60% compression under 6 lbf load, and/or 80% compression under 20 lbf load, for example. In certain embodiments, one or more gasses, such as air, nitrogen, carbon dioxide, and/or oxygen, for example, can be bubbled through and/or contained within the tissue thickness compensator. In at least one embodiment, a tissue thickness compensator can comprise beads therein which comprise between approximately 50% and approximately 75% of the material stiffness comprising the tissue thickness compensator. In various embodiments, a tissue thickness compensator can comprise hyaluronic acid, nutrients, fibrin, thrombin, platelet rich plasma, Sulfasalazine (Azulfidine®—5ASA+Sulfapyridine diazo bond))—prodrug—colonic bacterial (Azoreductase), Mesalamine (5ASA with different prodrug configurations for delayed release), Asacol® (5ASA+Eudragit-S coated−pH>7 (coating dissolution)), Pentasa® (5ASA+ethylcellulose coated—time/pH dependent slow release), Mesasal® (5ASA+Eudragit-L coated−pH>6), Olsalazine (5ASA+5ASA—colonic bacterial (Azoreductase)), Balsalazide (5ASA+4Aminobenzoyl-B-alanine)—colonic bacterial (Azoreductase)), Granulated mesalamine, Lialda (delay and SR formulation of mesalamine), HMPL-004 (herbal mixture that may inhibit TNF-alpha, interleukin-1 beta, and nuclear-kappa B activation), CCX282-B (oral chemokine receptor antagonist that interferes with trafficking of T lymphocytes into the intestinal mucosa), Rifaximin (nonabsorbable broad-spectrum antibiotic), Infliximab, murine chymieric (monoclonal antibody directed against TNF-alpha-approved for reducing signs/symptoms and maintaining clinical remission in adult/pediatric patients with moderate/severe luminal and fistulizing Crohn's disease who have had inadequate response to conventional therapy), Adalimumab, Total Human IgG1 (anti-TNF-alpha monoclonal antibody—approved for reducing signs/symptoms of Crohn's disease, and for the induction and maintenance of clinical remission in adult patients with moderate/severe active Crohn's disease with inadequate response to conventional therapies, or who become intolerant to Infliximab), Certolizumab pegoll, humanized anti-TNF FAB′ (monoclonal antibody fragment linked to polyethylene glycol—approved for reducing signs/symptoms of Crohn's disease and for the induction and maintenance of response in adult patients w/moderate/severe disease with inadequate response to conventional therapies), Natalizumab, First non-TNF-alpha inhibitor (biologic compound approved for Crohn's disease), Humanized monoclonal IgG4 antibody (directed against alpha-4 integrin—FDA approved for inducing and maintaining clinical response and remission in patients with moderate/severe disease with evidence of inflammation and who have had inadequate response to or are unable to tolerate conventional Crohn's therapies and inhibitors of TNF-alpha), concomitant Immunomodulators potentially given with Infliximab, Azathioprine 6-Mercaptopurine (purine synthesis inhibitor—prodrug), Methotrexate (binds dihydrofolate reductase (DHFR) enzyme that participates in tetrahydrofolate synthesis, inhibits all purine synthesis), Allopurinol and Thioprine therapy, PPI, H2 for acid suppression to protect the healing line, C-Diff—Flagyl, Vancomycin (fecal translocation treatment; probiotics; repopulation of normal endoluminal flora), and/or Rifaximin (treatment of bacterial overgrowth (notably hepatic encephalopahy); not absorbed in GI tract with action on intraluminal bacteria), for example. As described herein, a tissue thickness compensator can compensate for variations in the thickness of tissue that is captured within the staples ejected from a staple cartridge and/or contained within a staple line, for example. Stated another way, certain staples within a staple line can capture thick portions of the tissue while other staples within the staple line can capture thin portions of the tissue. In such circumstances, the tissue thickness compensator can assume different heights or thicknesses within the staples and apply a compressive force to the tissue captured within the staples regardless of whether the captured tissue is thick or thin. In various embodiments, a tissue thickness compensator can compensate for variations in the hardness of the tissue. For instance, certain staples within a staple line can capture highly compressible portions of the tissue while other staples within the staple line can capture portions of the tissue which are less compressible. In such circumstances, the tissue thickness compensator can be configured to assume a smaller height within the staples that have captured tissue having a lower compressibility, or higher hardness, and, correspondingly, a larger height within the staples that have captured tissue having a higher compressibility, or lower hardness, for example. In any event, a tissue thickness compensator, regardless of whether it compensates for variations in tissue thickness and/or variations in tissue hardness, for example, can be referred to as a ‘tissue compensator’ and/or as a ‘compensator’, for example. The devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. In either case, however, the device can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, the device can be disassembled, and any number of the particular pieces or parts of the device can be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, the device can be reassembled for subsequent use either at a reconditioning facility, or by a surgical team immediately prior to a surgical procedure. Those skilled in the art will appreciate that reconditioning of a device can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application. Preferably, the invention described herein will be processed before surgery. First, a new or used instrument is obtained and if necessary cleaned. The instrument can then be sterilized. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and instrument are then placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation kills bacteria on the instrument and in the container. The sterilized instrument can then be stored in the sterile container. The sealed container keeps the instrument sterile until it is opened in the medical facility. Any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated materials does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material. While this invention has been described as having exemplary designs, the present invention may be further modified within the spirit and scope of the disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.

11857188

DETAILED DESCRIPTION Particular embodiments of the present surgical instruments are described hereinbelow with reference to the accompanying drawings; however, it is to be understood that the disclosed embodiments are merely exemplary of the disclosure and may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure. Well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in any unnecessary detail. While the following disclosure is presented with respect to a linear surgical stapler where staples are sequentially fired, it should be understood that the features of the presently described surgical instruments may be readily adapted for use in any type of surgical grasping, clamping, cutting, or sealing instruments, whether or not the surgical clamping and cutting instrument applies a fastener. For example, the presently described drive member and actuation mechanism may be employed in an electrosurgical instrument wherein the jaws include electrodes for applying energy to tissue to treat (e.g., cauterize, ablate, fuse, or cut) the tissue. The surgical clamping and cutting instrument may be a minimally invasive (e.g., laparoscopic) instrument or an instrument used for open surgery. Additionally, the features of the presently described surgical stapling instruments may be readily adapted for use in surgical instruments that are activated using any technique within the purview of those skilled in the art, such as, for example, manually activated surgical instruments, powered surgical instruments (e.g., electro-mechanically powered instruments), robotic surgical instruments, and the like. FIG.1is a perspective view of a representative surgical instrument100in accordance with embodiments of the present disclosure having a proximal mechanism that may include input couplers180on a handle assembly, and an end effector110mounted on an elongated shaft106. Input couplers180typically provide a mechanical coupling between the drive tendons or cables of the instrument and motorized axes of the mechanical interface of a drive system. Input couplers180may interface with, and be driven by, corresponding output couplers (not shown) of a telesurgical surgery system, such as the system disclosed in U.S Pub. No. 2014/0183244A1, the entire disclosure of which is incorporated by reference herein. The input couplers180are drivingly coupled with one or more input members (not shown) that are disposed within the instrument shaft106. The input members are drivingly coupled with the end effector110. Input couplers180of the handle assembly can be adapted to mate with various types of motor packs (not shown), such as the stapler-specific motor packs disclosed in U.S. Pat. No. 8,912,746, or the universal motor packs disclosed in U.S. Pat. No. 8,529,582, the disclosures of both of which are incorporated by reference herein in their entirety. Further details of known input couplers and surgical systems are described, for example, in U.S. Pat. Nos. 8,597,280, 7,048,745, and10,016,244. Each of these patents is hereby incorporated by reference in its entirety. Actuation mechanisms of surgical instrument100employ drive cables that are used in conjunction with a system of motors and pulleys. Powered surgical systems, including robotic surgical systems that utilize drive cables connected to a system of motors and pulleys for various functions including opening and closing of jaws, as well as for movement and actuation of end effectors are well known. Further details of known drive cable surgical systems are described, for example, in U.S. Pat. Nos. 7,666,191 and 9,050,119 both of which are hereby incorporated by reference in their entireties. While described herein with respect to an instrument configured for use with a robotic surgical system, it should be understood that the wrist assemblies described herein may be incorporated into manually actuated instruments, electro-mechanical powered instruments, or instruments actuated in any other way. For example, instrument100may include a conventional handle assembly that includes, for example, a stationary handle and a movable handle, which serves as a mechanical actuator for a surgeon to manually operate end effector110. FIG.1Ashows the distal end portion of surgical instrument100, including an end effector110defining a longitudinal axis1-1and having a first jaw111, a second jaw112, a clevis140for mounting jaws111,112to the instrument, and an articulation mechanism, such as wrist assembly24. First jaw111includes an anvil115having staple-forming pockets116. In certain embodiments, second jaw112is a movable jaw configured to move from an open position to a closed position relative to first jaw111. In other embodiments, first jaw111is a movable jaw configured to move between open and closed positions relative to second jaw112. In still other embodiments, both jaws111,112are movable relative to each other. In the open position, a fresh stapling cartridge (sometimes referred to as a reload) can be loaded into second jaw112and tissue may be positioned between the jaws111,112. In the closed position, jaws111,112cooperate to clamp tissue such that the staple cartridge and the anvil115are in close cooperative alignment. Referring now toFIGS.1B and1C, a representative staple cartridge122may include a plurality of staple assemblies, each comprising one or more staples124supported on corresponding staple drivers or pusher126provided within respective staple apertures127formed in cartridge122. Of course, it should be recognized that the particular staple cartridge122shown inFIGS.1B and1Cis representative only. Other embodiments of staple cartridge will be known to those of skill in the art. The staple assemblies each include at least one (preferably 2-4) staple pushers126removably coupled to at least one (preferably 2-4) staples124. The staple assemblies are preferably arranged within apertures127such that staple pusher126is situated near a bottom surface of staple cartridge122and staples124have their legs facing a top surface of cartridge122. As discussed above, the entire staple cartridge122can be loaded into a jaw of an end effector for use in surgery as described in more detail below. In certain embodiments, staple pusher(s)126include one or more supporting elements extending above their top surface for providing support to staples124when they are resting thereon. Of course, other suitable geometric designs of staple pusher126may be used to receive and hold staple124in accordance with the present invention. For example, pusher126may have a recess (not shown) for receiving staple124, as is described in commonly-assigned, provisional patent application Ser. No. 62/855,371, filed May 31, 2019. Alternatively, pusher126may have a flatter upper surface (i.e., without a recess or pocket) that allows the backspan of staple124to rest thereon, as is described in commonly-assigned, provisional patent application Ser. No. 62,783,460, the complete disclosures of both of these applications are hereby incorporated by reference in their entirety for all purposes. Cartridge122also may include a shuttle123having an inclined distal surface125that, upon distal movement, sequentially acts on staple pushers126, camming them upwardly, thereby moving staples124into deforming contact with an anvil of a surgical instrument. Shuttle123may be part of a drive member150(FIGS.2and3) described in more detail below. In certain embodiments, drive member150may also include a knife128configured to translate distally through a channel114in cartridge122and to sever clamped, stapled tissue. In embodiments, knife128may simply be a sharpened edge on drive member150rather than a distinct structure within the cartridge. Cartridge122may be removably received within a jaw of a surgical instrument or, in single use embodiments, may be manufactured as part of the jaw. In certain embodiments, jaws111,112are attached to surgical instrument100via clevis140. Clevis140includes upper and lower portions that cooperate when assembled to form a protrusion145configured to engage tabs113(seeFIG.1A) of jaw111to securely mount jaw111in a fixed position on instrument100. Clevis140further includes an opening for receiving a pivot pin130defining a pivot axis around which jaw112pivots as described in more detail below. A more complete description of a suitable clevis140for use with the present invention may be found in commonly-assigned, provisional patent application Ser. Nos. 62,783,444, filed Dec. 21, 2018; 62,783,460, filed Dec. 21, 2018; 62,747,912, filed Oct. 19, 2018; and 62,783,429, filed Dec. 21, 2018, the complete disclosures of which are hereby incorporated by reference in their entirety for all purposes. Of course, it will be recognized by those skilled in the art that other coupling mechanisms known by those skilled in the art may be used with the present invention to attach the jaws111,112to the proximal portion of surgical instrument100. End effector110may be articulated in multiple directions by an articulation mechanism. In certain embodiments, the articulation mechanism may be a wrist assembly24as shown, although other articulation mechanisms are contemplated. Preferred embodiments of wrist assembly24according to the present disclosure are discussed below in relation toFIGS.4-11. As shown inFIG.2, an illustrative drive member150may include a body151, an upper shoe152, a lower shoe154, a central portion156and shuttle123having inclined distal surfaces125. Actuation assembly190includes a drive cable171, a coil120, a sheath121surrounding coil120, and a proximal drive rod (not shown). Drive cable171includes an enlarged distal end173. Upper shoe152of drive member150includes bore158into which drive cables171are routed. Sheath121may function to promote stability, smooth movement, and prevent buckling upon actuation of surgical instrument100. Sheath121may be made from polyimide, or any other suitable material having the requisite strength requirements such as various reinforced plastics, a nickel titanium alloy such as NITINOL™, poly para-phenyleneterphtalamide materials such as KEVLAR™ commercially available from DuPont. Those of skill in the art may envision other suitable materials. The proximal surface of upper shoe152is configured to be engaged by a coil120of actuation assembly190such that coil120may apply force to upper shoe152to advance drive member150distally. A knife128may be formed on drive member150along the distal edge between upper shoe152and central portion156. Enlarged distal end173of drive cable171resides within an enlarged distal portion159of bore158in upper shoe152of drive member150, such that the proximal face157of enlarged distal end173may apply a retraction force on upper shoe152when the drive cable171is pulled proximally. The drive rod is operationally connected to an actuator (e.g., input couplers180), which allows distal translation and proximal retraction of actuation assembly190. Those skilled in the art will recognize that in a manually actuated instrument, the actuator may be a movable handle, such as movable handle102bshown inFIG.1; in a powered instrument the actuator may be a button (not shown) that causes a motor to act on the drive rod; and in a robotic system, the actuator may be a control device such as the control devices described below in connection withFIGS.12and13. In alternative embodiments, coil120of actuation assembly190may be coupled with lower shoe154instead of upper shoe152. In these embodiments, coil120applies force to lower shoe153to advance drive member150distally. Upper shoe152of drive member150is substantially aligned with and translates through a channel118in first jaw111, while lower shoe154of drive member150is substantially aligned with and translates through a channel114in jaw112and below jaw112(seeFIG.3). During actuation of illustrative surgical instrument100, the drive rod applies force to coil120, thereby causing coil120to apply force to upper shoe152of drive member150, translating it distally initially closing jaws111,112and then ejecting staples from a staple cartridge to staple tissue. After stapling is complete, the drive rod may apply a force in the proximal direction to effect retraction of drive member. During retraction, enlarged distal end173of drive cable171is obstructed by wall157of enlarged portion159of bore158, causing drive cable171to apply force to upper shoe152of drive member150, thereby translating drive member150in the proximal direction. One of ordinary skill in the art will appreciate that drive member150, drive cable171, and the drive rod all move in unison and remain in the same relative position to each other. Upon actuation of the surgical instrument, drive member150is advanced distally through end effector110to move jaws111,112from the open position to the closed position, after which shuttle123and knife128are advanced distally through a staple cartridge to staple and cut tissue grasped between jaws111,112. Of course, it will be recognized by those skilled in the art that drive member150may be any structure capable of pushing at least one of a shuttle or a knife of a surgical stapling instrument with the necessary force to effectively sever or staple human tissue. Drive member150may be an I-beam, an E-beam, or any other type of drive member capable of performing similar functions. Drive member150is movably supported on the surgical stapling instrument100such that it may pass distally through a staple cartridge and upper fixed jaw111and lower jaw112when the surgical stapling instrument is fired (e.g., actuated). FIGS.4-6illustrate a distal portion of surgical instrument100that includes a wrist assembly24with at least two degrees of freedom and provides for attachment of end effector110to elongated instrument shaft106for articulation of end effector110about at least two orthogonal axes relative to the instrument shaft106. Wrist assembly24is configured to yaw about axis2-2(seeFIG.4), which is perpendicular to the longitudinal axis1-1of instrument shaft106. Wrist assembly24is also configured to pitch about axis3-3(seeFIG.5), which is perpendicular to axis1-1and axis2-2. As shown, the yaw axis2-2is proximal (farther from the end effector110) to the pitch axis3-3, however this is not a requirement and in some embodiments the yaw axis2-2may be distal to the pitch axis3-3. In certain embodiments, wrist assembly24may only be configured to rotate around one or more of the axes1-1,2-2or3-3. As shown inFIG.6, wrist assembly24preferably includes a proximal outer link200, a middle outer link202, and a distal outer link204. These three links determine the kinematic pitch and yaw motion of the wrist assembly24. As shown, the interface between the proximal outer link200and the middle outer link202defines joint212that determines yaw movement of wrist assembly24. The interface between the outer distal link204and the middle outer link202defines joint214that determines pitch movement of wrist assembly24. However, in an alternative wrist configuration, this relationship can be reversed such that wrist assembly24pitches between proximal outer link200and middle outer link202and yaws between distal outer link200and middle outer link202(e.g., by rotating end effector110relative to wrist assembly24by 90 degrees). In other embodiments, wrist assembly24may only include middle outer link202and one of proximal or distal outer links200,204. In this embodiment, wrist assembly24is configured for rotation about a single axis. Cable portions206are drivingly coupled with the wrist assembly24and actuated to impart motion to wrist assembly24. In some embodiments, cable portions206can be individually secured to a portion of distal outer link204. Differential movement of cable portions206can be used to actuate wrist assembly24to pitch and yaw at various angles. Cable portions206can be drivingly coupled to one or more of input couplers180shown inFIG.1. Wrist assembly also includes a proximal inner link208and a distal inner link210each having a pair of pivot posts282formed thereon. Inner links208,218and the function of pivot posts282are discussed in further detail below. Wrist assembly24including joints212,214may provide a desired amount of motion, such as +/−90 degrees in a pitch or yaw direction. In embodiments, a single joint212can provide up to a 90 degree angular deflection. According to an exemplary embodiment, a wrist may include a plurality of joints212,214to achieve higher ranges of motion (up to roll limit angles), such as, for example, wrists having a range of motion of up to +/−180 degrees in a pitch or yaw direction. Additional details of other joints usable with the embodiments disclosed herein, are disclosed in International Patent Publication No. WO 2015/127250A1, the entire disclosure of which is incorporated by reference herein for all purposes. With attention toFIG.7, proximal joint212is shown that is representative of the interfaces between the outer links200,202, and inner link208. Distal joint214has a similar construction. Proximal outer link200may include one or more gear teeth218and a bearing projection222. Middle outer link202includes one or more gear teeth220and a bearing projection230. Gear teeth218,220can provide enhanced timing to assist with accurately positioning outer links200,202, including, for example, returning outer links200,202to a neutral position (e.g., zero angle roll alignment), and to enhance smoothness of the motion between outer links200,202such as when outer links200,202are reoriented relative to one another. Bearing projections222,230of outer links200,202may include passages to permit cable portions206to pass through. Bearing projections222,230are located at an outboard or lateral location relative to the central apertures250of links200,202(seeFIG.8), thereby allowing for routing of other mechanisms (e.g., a drive cable171) through the central apertures of links200,202. Gear teeth218,220engage and disengage during movement to maintain timing (prevent slip) between the rolling contacts. Actuation kinematics between the outer links200,202are determined at least in part by the radius of rolling contacts205,215. The bearing projections222,230include curved surfaces205,215that can engage at suitable points throughout all angular motion to help reduce compressive strain on the gear teeth218,220. Proximal inner link208may include pivot posts282(e.g., configured as protruding journals). The pivot posts282are received within and interface with recesses or cutouts280(e.g., configured as journal bearings) at medial surfaces of the outer links200,202. Together, pivot posts282and cutouts280define a rocking hinge. A rocking hinge as defined in the present disclosure is a hinge that is not fixed, which means that inner link208and outer links200,202do not rotate about a shared axis, as discussed further below. As shown inFIG.7, outer links200,202each define an effective rolling radius, which is the distance between the center point285of each link200,202to the outer surface287of the circle defined by the articulation of each link200,202. Outer links200,202further define a centerline289that extends linearly between the two center points285. Pivot posts282each have a center283and define a separate centerline291therebetween. In a conventional fixed hinge joint, the centerline291of the pivot posts282would always be substantially coincident with the centerline289of the joints as links200,2002relative to each other. In the rocking hinge of the present invention, however, centerline291of pivot posts282moves away from centerline289of the joints as links200,202articulate relative to each other. Thus, the centerline291of the posts282is not fixed to the centerline289of the rolling radius of outer links200,202, but rather this centerline291moves away from the centerline289of the rolling radius (in the direction of articulation) as the outer links200,202articulate relative to each other. In the preferred embodiment, cutouts280each have a cross-sectional area that is larger than the cross-sectional area of pivot posts282. Thus, pivot posts282are configured to move within cutouts280(i.e., there is sufficient space within cutouts280to allow the centers283of posts282to move or translate relative to outer links200,202during the articulation of outer links200,202relative to each other). Accordingly, inner link108moves relative to outer links200,202during articulation of outer links200,202relative to each other. In a fixed hinge, the centers283of posts282would not move relative to outer links200,202and inner link208would rotate about a shared axis with outer links200,202. The rocking hinge of the present disclosure allows for a more compact assembly without sacrificing the internal bend radius of the joint, which offers many advantages. For example, the rolling radii of the links200,202can be reduced without reducing the link or disk length (seeFIG.8), and thereby reducing the internal bend radius that typically results from reducing the size of the rolling radius of a conventional fixed hinge design. Thus, the use of a rocking hinge in a wrist assembly in accordance with the present disclosure allows the designer to reduce the size of the rolling radii without increasing the disk length, thus reducing the overall length of the middle outer link202and yielding a more compact wrist assembly. A more compact wrist assembly and, in particular, a smaller rolling radius reduces the potential for tissue pinching to occur, and allows for wrist assembly designs that may not need a cover. In addition, the larger internal bend radius associated with the rocking hinge design of the present disclosure, that is, the amount that the internal components of the wrist must bend, allows for better drive efficiency, less sheath wear, more robust outer tube structures, and improved fitness of the wrist to provide before improved steering forces. Pivot posts282may have a generally rectangular shape as shown, or may be circular, triangular, oval or other suitable shape. Cutouts280may include a profile that matches the outer surface of pivot posts282or they may be of any desired shape capable of supporting a pivot post282as it pivots during articulation. As shown inFIG.7, posts282each have a slightly curved (convex) contact surface253configured to contact a substantially flat contact surface251on the inner surfaces of cutouts280of outer links200,202. Each side of proximal inner link208may include a pair of commonly aligned pivot posts282that interface with the cutouts280for a total of four pivot posts282per inner link. Each pair of pivot posts282is separated to provide an internal passage244(seeFIG.11A) for other mechanisms (e.g., a drive cable or mechanism). Joint214may have a similar construction as joint212described above, with inner link210joining outer distal link204and the middle outer link202to form a rocking hinge. It should be understood that only one of hinges212or214may be a rocking hinge as described herein, with the other of hinges212or214being a conventional fixed hinge or other suitable design.FIG.8illustrates a partial cross-sectional view of outer link202. As shown, link202includes a central aperture250for allowing routing of other mechanisms (e.g., a drive cable171) through wrist assembly24. Contact surface251of link202is substantially flat as discussed above.FIG.8also illustrates the disk length and overall pivot length of outer link202. In certain embodiments, the rolling radius of each link can be reduced while maintaining the overall pivot length of the middle outer link. This results in an increased link or disk length, which can significantly improve the mechanical strength of the middle outer link202and allow for a more compact design. In other embodiments, the rolling radius of the link can be reduced without increasing the disk length. This results in a reduced pivot length of the middle outer link202, thereby yielding a more compact wrist assembly. FIGS.9A and9Billustrate an alternative embodiment of proximal joint212. In this embodiment, joint212has substantially the same construction as discussed above in relation toFIGS.7and8, expect with reversed contact profiles. As shown, contact surface253of posts282is substantially flat, whereas contact surface251of outer links200,202is curved. Contact surface251is preferably a radius that is substantially concentric with the rolling radius of outer links200,202. This design provides the benefit that the link maintains contact through a higher range of motion than the design ofFIGS.7and8. In an exemplary embodiment, each inner link208,210comprises a two-piece construction, as depicted inFIGS.10,11A and11Bfor inner link210. These figures also depict a technique for assembling the inner links to the outer links. As seen inFIG.10, first link portion210aand second link portion210bof distal inner link210are positioned to place pivot posts282into cutouts280of middle outer link202. First link portion210aand second link portion210bare inserted at angles such that gear teeth248of each portion intermesh to cause alignment of the portions into the formation shown atFIG.10. Gear teeth248are an assembly aid that eliminates the need for pins or other fasteners, and are not used for movement beyond assembly. However, in some embodiments, fasteners can be used in lieu of the gear teeth. After the link portions210a,210bare assembled into a complete distal inner link210, the distal outer link204is assembled onto the remaining exposed pivot posts282into the formation shown atFIG.4. FIG.12is a partial cut-a-way view of instrument100, illustrating the interaction between wrist assembly24and drive member150according to certain embodiments of the present disclosure. In these embodiments, drive member150includes a drive rod46that slides axially within a sheath48. An additional sheath52may be used to further support the drive rod46. Additional sheath52is fixed to a distal end portion of the wrist assembly24and is flexible to bend with movement of the wrist assembly24, but is constrained from moving axially. Additional sheath52and the internal passage provided by the inner links208,210serve to guide and constrain the drive member150during axial movement. Additional sheath52and the inner passage prevent the drive member from buckling under compressive loading (i.e. distal movement while cutting and stapling). Prior wrist designs, such as disclosed in the aforementioned Int'l. Pub. No. WO 2015/127250A1, rely on tensioned cables to maintain the outer links in position. Inner links208,210serve to prevent separation of the outer links200,202,204when the driving forces overcome the steering cable tension. Pivot posts282of the inner links208,210advantageously maintain the outer links in position when the drive member150moves in a distal direction, therefore maintaining the structure of the wrist assembly24. As also seen inFIG.12, a beam member28may be driven distally to close movable jaw112(shown more clearly inFIG.1). Beam member28can also deploy staples from the cartridge into tissue, and then cut the stapled tissue. Specifically, beam member28can also actuate a sled (not shown, but such as disclosed in Pub. No. US 2014/0183244 A1) configured for ejecting staples out of movable jaw112during distal movement of beam member28. Beam member28includes an upper beam portion30that is configured to slide within fixed jaw111. Lower beam portion32engages a ramp34on movable jaw112and, upon distal movement of beam member28, urges jaw112towards the closed position relative to jaw111. Complete closure of the jaw112is achieved when the lower beam portion32moves distally past the ramp34. Proximal movement of the lower beam portion32off of the ramp34removes the closure force applied by the beam member28. A resilient device or secondary mechanism29can then cause closed or partially closed jaw112toward the open position. Thus, back and forth movement of lower beam portion32along ramp34can toggle the end effector110between the open and closed positions. FIG.13illustrates, as an example, a top view of an operating room employing a robotic surgical system. The robotic surgical system in this case is a robotic surgical system300including a Console (“C”) utilized by a Surgeon (“S”) while performing a minimally invasive diagnostic or surgical procedure, usually with assistance from one or more Assistants (“A”), on a Patient (“P”) who is lying down on an Operating table (“O”). The Console includes a monitor304for displaying an image of a surgical site to the Surgeon, left and right manipulatable control devices308and309, a foot pedal305, and a processor302. The control devices308and309may include any one or more of a variety of input devices such as joysticks, gloves, trigger-guns, hand-operated controllers, or the like. The processor302may be a dedicated computer that may be integrated into the Console or positioned next to it. The Surgeon performs a minimally invasive surgical procedure by manipulating the control devices308and309(also referred to herein as “master manipulators”) so that the processor302causes their respectively associated robotic arm assemblies,328and329, (also referred to herein as “slave manipulators”) to manipulate their respective removably coupled surgical instruments338and339(also referred to herein as “tools”) accordingly, while the Surgeon views the surgical site in 3-D on the Console monitor304as it is captured by a stereoscopic endoscope340. Each of the tools338and339, as well as the endoscope340, may be inserted through a cannula or other tool guide (not shown) into the Patient so as to extend down to the surgical site through a corresponding minimally invasive incision such as incision366. Each of the robotic arms is conventionally formed of links, such as link362, which are coupled together and manipulated through motor controlled or active joints, such as joint363. The number of surgical tools used at one time and consequently, the number of robotic arms being used in the system300will generally depend on the diagnostic or surgical procedure and the space constraints within the operating room, among other factors. If it is necessary to change one or more of the tools being used during a procedure, the Assistant may remove the tool no longer being used from its robotic arm, and replace it with another tool331from a Tray (“T”) in the operating room. The monitor304may be positioned near the Surgeon's hands so that it will display a projected image that is oriented so that the Surgeon feels that he or she is actually looking directly down onto the operating site. To that end, images of the tools338and339may appear to be located substantially where the Surgeon's hands are located. The processor302performs various functions in the system300. One important function that it performs is to translate and transfer the mechanical motion of control devices308and309to their respective robotic arms328and329through control signals over bus310so that the Surgeon can effectively manipulate their respective tools338and339. Another important function is to implement various control system processes as described herein. Although described as a processor, it is to be appreciated that the processor302may be implemented in practice by any combination of hardware, software and firmware. Also, its functions as described herein may be performed by one unit, or divided up among different components, each of which may be implemented in turn by any combination of hardware, software and firmware. For additional details on robotic surgical systems, see, e.g., commonly owned U.S. Pat. No. 6,493,608 “Aspects of a Control System of a Minimally Invasive Surgical Apparatus,” and commonly owned U.S. Pat. No. 6,671,581 “Camera Referenced Control in a Minimally Invasive Surgical Apparatus,” which are hereby incorporated herein by reference in their entirety for all purposes. FIG.14illustrates, as an example, a side view of a simplified (not necessarily in proportion or complete) illustrative robotic arm assembly400(which is representative of robotic arm assemblies328and329) holding a surgical instrument450(which is representative of tools338and339) for performing a surgical procedure. The surgical instrument450is removably held in tool holder440. The arm assembly400is mechanically supported by a base401, which may be part of a patient-side movable cart or affixed to the operating table or ceiling. It includes links402and403, which are coupled together and to the base401through setup joints404and405. The setup joints404and405in this example are passive joints that allow manual positioning of the arm400when their brakes are released. For example, setup joint404allows link402to be manually rotated about axis406, and setup joint405allows link403to be manually rotated about axis407. Although only two links and two setup joints are shown in this example, more or less of each may be used as appropriate in this and other robotic arm assemblies in conjunction with the present invention. For example, although setup joints404and405are useful for horizontal positioning of the arm400, additional setup joints may be included and useful for limited vertical and angular positioning of the arm400. For major vertical positioning of the arm400, however, the arm400may also be slidably moved along the vertical axis of the base401and locked in position. The robotic arm assembly400also includes three active joints driven by motors. A yaw joint410allows arm section430to rotate around an axis461, and a pitch joint420allows arm section430to rotate about an axis perpendicular to that of axis461and orthogonal to the plane of the drawing. The arm section430is configured so that sections431and432are always parallel to each other as the pitch joint420is rotated by its motor. As a consequence, the instrument450may be controllably moved by driving the yaw and pitch motors so as to pivot about the pivot point462, which is generally located through manual positioning of the setup joints404and405so as to be at the point of incision into the patient. In addition, an insertion gear445may be coupled to a linear drive mechanism (not shown) to extend or retract the instrument450along its axis463. Although each of the yaw, pitch and insertion joints or gears,410,420and445, is controlled by an individual joint or gear controller, the three controllers are controlled by a common master/slave control system so that the robotic arm assembly400(also referred to herein as a “slave manipulator”) may be controlled through user (e.g., surgeon) manipulation of its associated master manipulator. A more complete description of illustrative robotic surgical systems for use with the present invention can be found in commonly-assigned U.S. Pat. Nos. 9,295,524, 9,339,344, 9,358,074, and 9,452,019, the complete disclosures of which are hereby incorporated by reference in their entirety for all purposes. While several embodiments have been shown in the drawings, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of presently disclosed embodiments. Thus, the scope of the embodiments should be determined by the appended claims and their legal equivalents, rather than by the examples given. Persons skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Various alternatives and modifications can be devised by those skilled in the art without departing from the disclosure. Accordingly, the present disclosure is intended to embrace all such alternatives, modifications and variances. As well, one skilled in the art will appreciate further features and advantages of the present disclosure based on the above-described embodiments. Accordingly, the present disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.

11857189

DETAILED DESCRIPTION Applicant of the present application also owns the following patent applications that have been filed on Jun. 28, 2012 and which are each herein incorporated by reference in their respective entireties:1. U.S. patent application Ser. No. 13/536,271, entitled FLEXIBLE DRIVE MEMBER, now U.S. Pat. No. 9,204,879.2. U.S. patent application Ser. No. 13/536,288, entitled MULTI-FUNCTIONAL POWERED SURGICAL DEVICE WITH EXTERNAL DISSECTION FEATURES, now U.S. Patent Application Publication No. 2014/0005718.3. U.S. patent application Ser. No. 13/536,277, entitled COUPLING ARRANGEMENTS FOR ATTACHING SURGICAL END EFFECTORS TO DRIVE SYSTEMS THEREFOR, now U.S. Patent Application Publication No. 2014/0001234.4. U.S. patent application Ser. No. 13/536,295, entitled ROTARY ACTUATABLE CLOSURE ARRANGEMENT FOR SURGICAL END EFFECTOR, now U.S. Pat. No. 9,119,657.5. U.S. patent application Ser. No. 13/536,326, entitled SURGICAL END EFFECTORS HAVING ANGLED TISSUE-CONTACTING SURFACES, now U.S. Pat. No. 9,289,256.6. U.S. patent application Ser. No. 13/536,303, entitled INTERCHANGEABLE END EFFECTOR COUPLING ARRANGEMENT, now U.S. Pat. No. 9,028,494.7. U.S. patent application Ser. No. 13/536,393, entitled SURGICAL END EFFECTOR JAW AND ELECTRODE CONFIGURATIONS, now U.S. Patent Application Publication No. 2014/0005640.8. U.S. patent application Ser. No. 13/536,362, entitled MULTI-AXIS ARTICULATING AND ROTATING SURGICAL TOOLS, now U.S. Pat. No. 9,125,662.9. U.S. patent application Ser. No. 13/536,284, entitled DIFFERENTIAL LOCKING ARRANGEMENTS FOR ROTARY POWERED SURGICAL INSTRUMENTS, now U.S. Pat. No. 9,072,536.10. U.S. patent application Ser. No. 13/536,374, entitled INTERCHANGEABLE CLIP APPLIER, now U.S. Pat. No. 9,561,038.11. U.S. patent application Ser. No. 13/536,301, entitled ROTARY DRIVE SHAFT ASSEMBLIES FOR SURGICAL INSTRUMENTS WITH ARTICULATABLE END EFFECTORS, now U.S. Pat. No. 8,747,238.12. U.S. patent application Ser. No. 13/536,313, entitled ROTARY DRIVE ARRANGEMENTS FOR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2014/0005678.13. U.S. patent application Ser. No. 13/536,323, entitled ROBOTICALLY POWERED SURGICAL DEVICE WITH MANUALLY-ACTUATABLE REVERSING SYSTEM, now U.S. Pat. No. 9,408,606.14. U.S. patent application Ser. No. 13/536,379, entitled REPLACEABLE CLIP CARTRIDGE FOR A CLIP APPLIER, now U.S. Pat. No. 9,649,111.15. U.S. patent application Ser. No. 13/536,386, entitled EMPTY CLIP CARTRIDGE LOCKOUT, now U.S. Pat. No. 9,282,974.16. U.S. patent application Ser. No. 13/536,360, entitled Surgical Instrument System Including Replaceable End Effectors, now U.S. Pat. No. 9,226,751.17. U.S. patent application Ser. No. 13/536,335, entitled ROTARY SUPPORT JOINT ASSEMBLIES FOR COUPLING A FIRST PORTION OF A SURGICAL INSTRUMENT TO A SECOND PORTION OF A SURGICAL INSTRUMENT, now U.S. Pat. No. 9,364,230.18. U.S. patent application Ser. No. 13/536,417, entitled ELECTRODE CONNECTIONS FOR ROTARY DRIVEN SURGICAL TOOLS, now U.S. Pat. No. 9,101,385. Applicant also owns the following patent applications that are each incorporated by reference in their respective entireties:U.S. patent application Ser. No. 13/118,259, entitled SURGICAL INSTRUMENT WITH WIRELESS COMMUNICATION BETWEEN A CONTROL UNIT OF A ROBOTIC SYSTEM AND REMOTE SENSOR, now U.S. Pat. No. 8,684,253;U.S. patent application Ser. No. 13/118,210, entitled ROBOTICALLY-CONTROLLED DISPOSABLE MOTOR DRIVEN LOADING UNIT, now U.S. Pat. No. 8,752,749;U.S. patent application Ser. No. 13/118,194, entitled ROBOTICALLY-CONTROLLED ENDOSCOPIC ACCESSORY CHANNEL, now U.S. Pat. No. 8,992,422;U.S. patent application Ser. No. 13/118,253, entitled ROBOTICALLY-CONTROLLED MOTORIZED SURGICAL INSTRUMENT, now U.S. Pat. No. 9,386,983;U.S. patent application Ser. No. 13/118,278, entitled ROBOTICALLY-CONTROLLED SURGICAL STAPLING DEVICES THAT PRODUCE FORMED STAPLES HAVING DIFFERENT LENGTHS, now U.S. Pat. No. 9,237,891;U.S. patent application Ser. No. 13/118,190, entitled ROBOTICALLY-CONTROLLED MOTORIZED CUTTING AND FASTENING INSTRUMENT, now U.S. Pat. No. 9,179,912;U.S. patent application Ser. No. 13/118,223, entitled ROBOTICALLY-CONTROLLED SHAFT BASED ROTARY DRIVE SYSTEMS FOR SURGICAL INSTRUMENTS, now U.S. Pat. No. 8,931,682;U.S. patent application Ser. No. 13/118,263, entitled ROBOTICALLY-CONTROLLED SURGICAL INSTRUMENT HAVING RECORDING CAPABILITIES, now U.S. Patent Application Publication No. 2011/0295295;U.S. patent application Ser. No. 13/118,272, entitled ROBOTICALLY-CONTROLLED SURGICAL INSTRUMENT WITH FORCE FEEDBACK CAPABILITIES, now U.S. Patent Application Publication No. 2011/0290856;U.S. patent application Ser. No. 13/118,246, entitled ROBOTICALLY-DRIVEN SURGICAL INSTRUMENT WITH E-BEAM DRIVER, now U.S. Pat. No. 9,060,770; andU.S. patent application Ser. No. 13/118,241, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, now U.S. Pat. No. 9,072,535. Certain exemplary embodiments will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the devices and methods disclosed herein. One or more examples of these exemplary embodiments are illustrated in the accompanying drawings. Those of ordinary skill in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments and that the scope of the various exemplary embodiments of the present invention is defined solely by the claims. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other exemplary embodiments. Such modifications and variations are intended to be included within the scope of the present invention. FIG.1depicts a master controller12that is used in connection with a robotic arm slave cart20of the type depicted inFIG.2. Master controller12and robotic arm slave cart20, as well as their respective components and control systems are collectively referred to herein as a robotic system10. Examples of such systems and devices are disclosed in U.S. Pat. No. 7,524,320 which has been herein incorporated by reference. Thus, various details of such devices will not be described in detail herein beyond that which may be necessary to understand various exemplary embodiments disclosed herein. As is known, the master controller12generally includes master controllers (generally represented as14inFIG.1) which are grasped by the surgeon and manipulated in space while the surgeon views the procedure via a stereo display16. The master controllers12generally comprise manual input devices which preferably move with multiple degrees of freedom, and which often further have an actuatable handle for actuating tools (for example, for closing grasping jaws, applying an electrical potential to an electrode, or the like). As can be seen inFIG.2, the robotic arm cart20is configured to actuate a plurality of surgical tools, generally designated as30. Various robotic surgery systems and methods employing master controller and robotic arm cart arrangements are disclosed in U.S. Pat. No. 6,132,368, entitled MULTI-COMPONENT TELEPRESENCE SYSTEM AND METHOD, the full disclosure of which is incorporated herein by reference. As shown, the robotic arm cart20includes a base22from which, in the illustrated embodiment, three surgical tools30are supported. The surgical tools30are each supported by a series of manually articulatable linkages, generally referred to as set-up joints32, and a robotic manipulator34. These structures are herein illustrated with protective covers extending over much of the robotic linkage. These protective covers may be optional, and may be limited in size or entirely eliminated to minimize the inertia that is encountered by the servo mechanisms used to manipulate such devices, to limit the volume of moving components so as to avoid collisions, and to limit the overall weight of the cart20. The cart20generally has dimensions suitable for transporting the cart20between operating rooms. The cart20is configured to typically fit through standard operating room doors and onto standard hospital elevators. The cart20would preferably have a weight and include a wheel (or other transportation) system that allows the cart20to be positioned adjacent an operating table by a single attendant. Referring now toFIG.3, robotic manipulators34as shown include a linkage38that constrains movement of the surgical tool30. Linkage38includes rigid links coupled together by rotational joints in a parallelogram arrangement so that the surgical tool30rotates around a point in space40, as more fully described in U.S. Pat. No. 5,817,084, the full disclosure of which is herein incorporated by reference. The parallelogram arrangement constrains rotation to pivoting about an axis40a, sometimes called the pitch axis. The links supporting the parallelogram linkage are pivotally mounted to set-up joints32(FIG.2) so that the surgical tool30further rotates about an axis40b, sometimes called the yaw axis. The pitch and yaw axes40a,40bintersect at the remote center42, which is aligned along a shaft44of the surgical tool30. The surgical tool30may have further degrees of driven freedom as supported by manipulator50, including sliding motion of the surgical tool30along the longitudinal tool axis “LT-LT”. As the surgical tool30slides along the tool axis LT-LT relative to manipulator50(arrow40c), remote center42remains fixed relative to base52of manipulator50. Hence, the entire manipulator is generally moved to re-position remote center42. Linkage54of manipulator50is driven by a series of motors56. These motors actively move linkage54in response to commands from a processor of a control system. Motors56are also employed to manipulate the surgical tool30. An alternative set-up joint structure is illustrated inFIG.4. In this embodiment, a surgical tool30is supported by an alternative manipulator structure50′ between two tissue manipulation tools. Other embodiments may incorporate a wide variety of alternative robotic structures, including those described in U.S. Pat. No. 5,878,193, entitled AUTOMATED ENDOSCOPE SYSTEM FOR OPTIMAL POSITIONING, the full disclosure of which is incorporated herein by reference. Additionally, while the data communication between a robotic component and the processor of the robotic surgical system is described with reference to communication between the surgical tool30and the master controller12, similar communication may take place between circuitry of a manipulator, a set-up joint, an endoscope or other image capture device, or the like, and the processor of the robotic surgical system for component compatibility verification, component-type identification, component calibration (such as off-set or the like) communication, confirmation of coupling of the component to the robotic surgical system, or the like. A surgical tool100that is well-adapted for use with a robotic system10is depicted inFIG.5. As can be seen in that Figure, the surgical tool100includes a surgical end effector1000that comprises an endocutter. The surgical tool100generally includes an elongate shaft assembly200that is operably coupled to the manipulator50by a tool mounting portion, generally designated as300. The surgical tool100further includes an interface302which mechanically and electrically couples the tool mounting portion300to the manipulator. One interface302is illustrated inFIGS.6-10. In the embodiment depicted inFIGS.6-10, the tool mounting portion300includes a tool mounting plate304that operably supports a plurality of (four are shown inFIG.10) rotatable body portions, driven discs or elements306, that each include a pair of pins308that extend from a surface of the driven element306. One pin308is closer to an axis of rotation of each driven elements306than the other pin308on the same driven element306, which helps to ensure positive angular alignment of the driven element306. Interface302may include an adaptor portion310that is configured to mountingly engage a mounting plate304as will be further discussed below. The illustrated adaptor portion310includes an array of electrical connecting pins312(FIG.8) which may be coupled to a memory structure by a circuit board within the tool mounting portion300. While interface302is described herein with reference to mechanical, electrical, and magnetic coupling elements, it should be understood that a wide variety of telemetry modalities might be used, including infrared, inductive coupling, or the like in other embodiments. As can be seen inFIGS.6-9, the adapter portion310generally includes a tool side314and a holder side316. A plurality of rotatable bodies320are mounted to a floating plate318which has a limited range of movement relative to the surrounding adaptor structure normal to the major surfaces of the adaptor310. Axial movement of the floating plate318helps decouple the rotatable bodies320from the tool mounting portion300when levers or other latch formations along the sides of the tool mounting portion housing (not shown) are actuated. Other embodiments may employ other mechanisms/arrangements for releasably coupling the tool mounting portion300to the adaptor310. In the embodiment ofFIGS.6-10, rotatable bodies320are resiliently mounted to floating plate318by resilient radial members which extend into a circumferential indentation about the rotatable bodies320. The rotatable bodies320can move axially relative to plate318by deflection of these resilient structures. When disposed in a first axial position (toward tool side314) the rotatable bodies320are free to rotate without angular limitation. However, as the rotatable bodies320move axially toward tool side314, tabs322(extending radially from the rotatable bodies320) laterally engage detents on the floating plates so as to limit angular rotation of the rotatable bodies320about their axes. This limited rotation can be used to help drivingly engage the rotatable bodies320with drive pins332of a corresponding tool holder portion330of the robotic system10, as the drive pins332will push the rotatable bodies320into the limited rotation position until the pins332are aligned with (and slide into) openings334′. Openings334on the tool side314and openings334′ on the holder side316of rotatable bodies320are configured to accurately align the driven elements306(FIG.10) of the tool mounting portion300with the drive elements336of the tool holder330. As described above regarding inner and outer pins308of driven elements306, the openings334,334′ are at differing distances from the axis of rotation on their respective rotatable bodies306so as to ensure that the alignment is not 180 degrees from its intended position. Additionally, each of the openings334may be slightly radially elongate so as to fittingly receive the pins308in the circumferential orientation. This allows the pins308to slide radially within the openings334and accommodate some axial misalignment between the tool100and tool holder330, while minimizing any angular misalignment and backlash between the drive and driven elements. Openings334on the tool side314may be offset by about 90 degrees from the openings334′ (shown in broken lines) on the holder side316, as can be seen most clearly inFIG.9. In the embodiment ofFIGS.6-10, an array of electrical connector pins340are located on holder side316of adaptor310and the tool side314of the adaptor310includes slots342(FIG.9) for receiving a pin array (not shown) from the tool mounting portion300. In addition to transmitting electrical signals between the surgical tool100and the tool holder330, at least some of these electrical connections may be coupled to an adaptor memory device344(FIG.8) by a circuit board of the adaptor310. In the embodiment ofFIGS.6-10, a detachable latch arrangement346is employed to releasably affix the adaptor310to the tool holder330. As used herein, the term “tool drive assembly” when used in the context of the robotic system10, at least encompasses the adapter310and tool holder330and which have been collectively generally designated as110inFIG.6. As can be seen inFIG.6, the tool holder330includes a first latch pin arrangement337that is sized to be received in corresponding clevis slots311provided in the adaptor310. In addition, the tool holder330further has second latch pins338that are sized to be retained in corresponding latch clevises313in the adaptor310. SeeFIG.8. A latch assembly315is movably supported on the adapter310and has a pair of latch devises317formed therein that is biasable from a first latched position wherein the latch pins338are retained within their respective latch clevis313and an unlatched position wherein the devises317are aligned with devises313to enable the second latch pins338may be inserted into or removed from the latch devises313. A spring or springs (not shown) are employed to bias the latch assembly into the latched position. A lip on the tool side314of adaptor310slidably receives laterally extending tabs of the tool mounting housing (not shown). Referring now toFIGS.5and11-16, the tool mounting portion300operably supports a plurality of drive systems for generating various forms of control motions necessary to operate a particular type of end effector that is coupled to the distal end of the elongate shaft assembly200. As shown inFIGS.5and11-13, the tool mounting portion300includes a first drive system generally designated as350that is configured to receive a corresponding “first” rotary output motion from the tool drive assembly110of the robotic system10and convert that first rotary output motion to a first rotary control motion to be applied to the surgical end effector. In the illustrated embodiment, the first rotary control motion is employed to rotate the elongate shaft assembly200(and surgical end effector1000) about a longitudinal tool axis LT-LT. In the embodiment ofFIGS.5and11-13, the first drive system350includes a tube gear segment354that is formed on (or attached to) the proximal end208of a proximal closure tube segment202of the elongate shaft assembly200. The proximal end208of the proximal tube segment202is rotatably supported on the tool mounting plate304of the tool mounting portion300by a forward support cradle352that is mounted on the tool mounting plate304. See FIG.11. The tube gear segment354is supported in meshing engagement with a first rotational gear assembly360that is operably supported on the tool mounting plate304. As can be seen inFIG.11, the rotational gear assembly360comprises a first rotation drive gear362that is coupled to a corresponding first one of the driven discs or elements306on the holder side316of the tool mounting plate304when the tool mounting portion300is coupled to the tool drive assembly110. SeeFIG.10. The rotational gear assembly360further comprises a first rotary driven gear364that is rotatably supported on the tool mounting plate304. The first rotary driven gear364is in meshing engagement with a second rotary driven gear366which, in turn, is in meshing engagement with the tube gear segment354. Application of a first rotary output motion from the tool drive assembly110of the robotic system10to the corresponding driven element306will thereby cause rotation of the rotation drive gear362. Rotation of the rotation drive gear362ultimately results in the rotation of the elongate shaft assembly200(and the surgical end effector1000) about the longitudinal tool axis LT-LT (represented by arrow “R” inFIG.5). It will be appreciated that the application of a rotary output motion from the tool drive assembly110in one direction will result in the rotation of the elongate shaft assembly200and surgical end effector1000about the longitudinal tool axis LT-LT in a first rotary direction and an application of the rotary output motion in an opposite direction will result in the rotation of the elongate shaft assembly200and surgical end effector1000in a second rotary direction that is opposite to the first rotary direction. In embodiment ofFIGS.5and11-16, the tool mounting portion300further includes a second drive system generally designated as370that is configured to receive a corresponding “second” rotary output motion from the tool drive assembly110of the robotic system10and convert that second rotary output motion to a second rotary control motion for application to the surgical end effector. The second drive system370includes a second rotation drive gear372that is coupled to a corresponding second one of the driven discs or elements306on the holder side316of the tool mounting plate304when the tool mounting portion300is coupled to the tool drive assembly110. SeeFIG.10. The second drive system370further comprises a first rotary driven gear374that is rotatably supported on the tool mounting plate304. The first rotary driven gear374is in meshing engagement with a shaft gear376that is movably and non-rotatably mounted onto a proximal drive shaft segment380. In this illustrated embodiment, the shaft gear376is non-rotatably mounted onto the proximal drive shaft segment380by a series of axial keyways384that enable the shaft gear376to axially move on the proximal drive shaft segment380while being non-rotatably affixed thereto. Rotation of the proximal drive shaft segment380results in the transmission of a second rotary control motion to the surgical end effector1000. The second drive system370in the embodiment ofFIGS.5and11-16includes a shifting system390for selectively axially shifting the proximal drive shaft segment380which moves the shaft gear376into and out of meshing engagement with the first rotary driven gear374. For example, as can be seen inFIGS.11-13, the proximal drive shaft segment380is supported within a second support cradle382that is attached to the tool mounting plate304such that the proximal drive shaft segment380may move axially and rotate relative to the second support cradle382. In at least one form, the shifting system390further includes a shifter yoke392that is slidably supported on the tool mounting plate304. The proximal drive shaft segment380is supported in the shifter yoke392and has a pair of collars386thereon such that shifting of the shifter yoke392on the tool mounting plate304results in the axial movement of the proximal drive shaft segment380. In at least one form, the shifting system390further includes a shifter solenoid394that operably interfaces with the shifter yoke392. The shifter solenoid394receives control power from the robotic controller12such that when the shifter solenoid394is activated, the shifter yoke392is moved in the distal direction “DD”. In this illustrated embodiment, a shaft spring396is journaled on the proximal drive shaft segment380between the shaft gear376and the second support cradle382to bias the shaft gear376in the proximal direction “PD” and into meshing engagement with the first rotary driven gear374. SeeFIGS.11,13and14. Rotation of the second rotation drive gear372in response to rotary output motions generated by the robotic system10ultimately results in the rotation of the proximal drive shaft segment380and other drive shaft components coupled thereto (drive shaft assembly388) about the longitudinal tool axis LT-LT. It will be appreciated that the application of a rotary output motion from the tool drive assembly110in one direction will result in the rotation of the proximal drive shaft segment380and ultimately of the other drive shaft components attached thereto in a first direction and an application of the rotary output motion in an opposite direction will result in the rotation of the proximal drive shaft segment380in a second direction that is opposite to the first direction. When it is desirable to shift the proximal drive shaft segment380in the distal direction “DD” as will be discussed in further detail below, the robotic controller12activates the shifter solenoid390to shift the shifter yoke392in the distal direction “DD”. FIGS.17and18illustrate another embodiment that employs the same components of the embodiment depicted inFIGS.5and11-16except that this embodiment employs a battery-powered drive motor400for supplying rotary drive motions to the proximal drive shaft segment380. Such arrangement enables the tool mounting portion to generate higher rotary output motions and torque which may be advantageous when different forms of end effectors are employed. As can be seen in those Figures, the motor400is attached to the tool mounting plate304by a support structure402such that a driver gear404that is coupled to the motor400is retained in meshing engagement with the shaft gear376. In the embodiment ofFIGS.17and18, the support structure402is configured to removably engage latch notches303formed in the tool mounting plate304that are designed to facilitate attachment of a housing member (not shown) to the mounting plate304when the motor400is not employed. Thus, to employ the motor400, the clinician removes the housing from the tool mounting plate304and then inserts the legs403of the support structure into the latch notches303in the tool mounting plate304. The proximal drive shaft segment380and the other drive shaft components attached thereto are rotated about the longitudinal tool axis LT-LT by powering the motor400. As illustrated, the motor400is battery powered. In such arrangement, however, the motor400interface with the robotic controller12such that the robotic system10controls the activation of the motor400. In alternative embodiments, the motor400is manually actuatable by an on/off switch (not shown) mounted on the motor400itself or on the tool mounting portion300. In still other embodiments, the motor400may receive power and control signals from the robotic system. The embodiment illustrated inFIGS.5and11-16includes a manually-actuatable reversing system, generally designated as410, for manually applying a reverse rotary motion to the proximal drive shaft segment380in the event that the motor fails or power to the robotic system is lost or interrupted. Such manually-actuatable reversing system410may also be particularly useful, for example, when the drive shaft assembly388becomes jammed or otherwise bound in such a way that would prevent reverse rotation of the drive shaft components under the motor power alone. In the illustrated embodiment, the mechanically-actuatable reversing system410includes a drive gear assembly412that is selectively engageable with the second rotary driven gear376and is manually actuatable to apply a reversing rotary motion to the proximal drive shaft segment380. The drive gear assembly412includes a reversing gear414that is movably mounted to the tool mounting plate304. The reversing gear414is rotatably journaled on a pivot shaft416that is movably mounted to the tool mounting plate304through a slot418. SeeFIG.12. In the embodiment ofFIGS.5and11-16, the manually-actuatable reversing system410further includes a manually actuatable drive gear420that includes a body portion422that has an arcuate gear segment424formed thereon. The body portion422is pivotally coupled to the tool mounting plate304for selective pivotal travel about an actuator axis A-A (FIG.11) that is substantially normal to the tool mounting plate304. FIGS.11-14depict the manually-actuatable reversing system410in a first unactuated position. In one exemplary form, an actuator handle portion426is formed on or otherwise attached to the body portion422. The actuator handle portion426is sized relative to the tool mounting plate304such that a small amount of interference is established between the handle portion426and the tool mounting plate304to retain the handle portion426in the first unactuated position. However, when the clinician desires to manually actuate the drive gear assembly412, the clinician can easily overcome the interference fit by applying a pivoting motion to the handle portion426. As can also be seen inFIGS.11-14, when the drive gear assembly412is in the first unactuated position, the arcuate gear segment424is out of meshing engagement with the reversing gear414. When the clinician desires to apply a reverse rotary drive motion to the proximal drive shaft segment380, the clinician begins to apply a pivotal ratcheting motion to drive gear420. As the drive gear420begins to pivot about the actuation axis A-A, a portion of the body422contacts a portion of the reversing gear414and axially moves the reversing gear414in the distal direction DD taking the drive shaft gear376out of meshing engagement with the first rotary driven gear374of the second drive system370. SeeFIG.15. As the drive gear420is pivoted, the arcuate gear segment424is brought into meshing engagement with the reversing gear414. Continued ratcheting of the drive gear420results in the application of a reverse rotary drive motion to the drive shaft gear376and ultimately to the proximal drive shaft segment380. The clinician may continue to ratchet the drive gear assembly412for as many times as are necessary to fully release or reverse the associated end effector component(s). Once a desired amount of reverse rotary motion has been applied to the proximal drive shaft segment380, the clinician returns the drive gear420to the starting or unactuated position wherein the arcuate gear segment416is out of meshing engagement with the drive shaft gear376. When in that position, the shaft spring396once again biases the shaft gear376into meshing engagement with first rotary driven gear374of the second drive system370. In use, the clinician may input control commands to the controller or control unit of the robotic system10which “robotically-generates” output motions that are ultimately transferred to the various components of the second drive system370. As used herein, the terms “robotically-generates” or “robotically-generated” refer to motions that are created by powering and controlling the robotic system motors and other powered drive components. These terms are distinguishable from the terms “manually-actuatable” or “manually generated” which refer to actions taken by the clinician which result in control motions that are generated independent from those motions that are generated by powering the robotic system motors. Application of robotically-generated control motions to the second drive system in a first direction results in the application of a first rotary drive motion to the drive shaft assembly388. When the drive shaft assembly388is rotated in a first rotary direction, the firing member1200is driven in the distal direction “DD” from its starting position toward its ending position in the end effector1000. Application of robotically-generated control motions to the second drive system in a second direction results in the application of a second rotary drive motion to the drive shaft assembly388. When the drive shaft assembly388is rotated in a second rotary direction, the firing member1200is driven in the proximal direction “PD” from its ending position toward its starting position in the end effector1000. When the clinician desires to manually-apply rotary control motion to the drive shaft assembly388, the drive shaft assembly388is rotated in the second rotary direction which causes the firing member1200to move in the proximal direction “PD” in the end effector. Other embodiments containing the same components are configured such that the manual-application of a rotary control motion to the drive shaft assembly could cause the drive shaft assembly to rotate in the first rotary direction which could be used to assist the robotically-generated control motions to drive the firing member1200in the distal direction. The drive shaft assembly that is used to fire, close and rotate the end effector can be actuated and shifted manually allowing the end effector to release and be extracted from the surgical site as well as the abdomen even in the event that the motor(s) fail, the robotic system loses power or other electronic failure occurs. Actuation of the handle portion426results in the manual generation of actuation or control forces that are applied to the drive shaft assembly388′ by the various components of the manually-actuatable reversing system410. If the handle portion426is in its unactuated state, it is biased out of actuatable engagement with the reversing gear414. The beginning of the actuation of the handle portion426shifts the bias. The handle426is configured for repeated actuation for as many times as are necessary to fully release the firing member1200and the end effector1000. As illustrated inFIGS.5and11-16, the tool mounting portion300includes a third drive system430that is configured to receive a corresponding “third” rotary output motion from the tool drive assembly110of the robotic system10and convert that third rotary output motion to a third rotary control motion. The third drive system430includes a third drive pulley432that is coupled to a corresponding third one of the driven discs or elements306on the holder side316of the tool mounting plate304when the tool mounting portion300is coupled to the tool drive assembly110. SeeFIG.10. The third drive pulley432is configured to apply a third rotary control motion (in response to corresponding rotary output motions applied thereto by the robotic system10) to a corresponding third drive cable434that may be used to apply various control or manipulation motions to the end effector that is operably coupled to the shaft assembly200. As can be most particularly seen inFIGS.11and12, the third drive cable434extends around a third drive spindle assembly436. The third drive spindle assembly436is pivotally mounted to the tool mounting plate304and a third tension spring438is attached between the third drive spindle assembly436and the tool mounting plate304to maintain a desired amount of tension in the third drive cable434. As can be seen in the Figures, cable end portion434A of the third drive cable434extends around an upper portion of a pulley block440that is attached to the tool mounting plate304and cable end portion434B extends around a sheave pulley or standoff442on the pulley block440. It will be appreciated that the application of a third rotary output motion from the tool drive assembly110in one direction will result in the rotation of the third drive pulley432in a first direction and cause the cable end portions434A and434B to move in opposite directions to apply control motions to the end effector1000or elongate shaft assembly200as will be discussed in further detail below. That is, when the third drive pulley432is rotated in a first rotary direction, the cable end portion434A moves in a distal direction “DD” and cable end portion434B moves in a proximal direction “PD”. Rotation of the third drive pulley432in an opposite rotary direction result in the cable end portion434A moving in a proximal direction “PD” and cable end portion434B moving in a distal direction “DD”. The tool mounting portion300illustrated inFIGS.5and11-16includes a fourth drive system450that is configured to receive a corresponding “fourth” rotary output motion from the tool drive assembly110of the robotic system10and convert that fourth rotary output motion to a fourth rotary control motion. The fourth drive system450includes a fourth drive pulley452that is coupled to a corresponding fourth one of the driven discs or elements306on the holder side316of the tool mounting plate304when the tool mounting portion300is coupled to the tool drive assembly110. SeeFIG.10. The fourth drive pulley452is configured to apply a fourth rotary control motion (in response to corresponding rotary output motions applied thereto by the robotic system10) to a corresponding fourth drive cable454that may be used to apply various control or manipulation motions to the end effector that is operably coupled to the shaft assembly200. As can be most particularly seen inFIGS.11and12, the fourth drive cable454extends around a fourth drive spindle assembly456. The fourth drive spindle assembly456is pivotally mounted to the tool mounting plate304and a fourth tension spring458is attached between the fourth drive spindle assembly456and the tool mounting plate304to maintain a desired amount of tension in the fourth drive cable454. Cable end portion454A of the fourth drive cable454extends around a bottom portion of the pulley block440that is attached to the tool mounting plate304and cable end portion454B extends around a sheave pulley or fourth standoff462on the pulley block440. It will be appreciated that the application of a rotary output motion from the tool drive assembly110in one direction will result in the rotation of the fourth drive pulley452in a first direction and cause the cable end portions454A and454B to move in opposite directions to apply control motions to the end effector or elongate shaft assembly200as will be discussed in further detail below. That is, when the fourth drive pulley434is rotated in a first rotary direction, the cable end portion454A moves in a distal direction “DD” and cable end portion454B moves in a proximal direction “PD”. Rotation of the fourth drive pulley452in an opposite rotary direction result in the cable end portion454A moving in a proximal direction “PD” and cable end portion454B to move in a distal direction “DD”. The surgical tool100as depicted inFIG.5includes an articulation joint700. In such embodiment, the third drive system430may also be referred to as a “first articulation drive system” and the fourth drive system450may be referred to herein as a “second articulation drive system”. Likewise, the third drive cable434may be referred to as a “first proximal articulation cable” and the fourth drive cable454may be referred to herein as a “second proximal articulation cable”. The tool mounting portion300of the embodiment illustrated inFIGS.5and11-16includes a fifth drive system generally designated as470that is configured to axially displace a drive rod assembly490. The drive rod assembly490includes a proximal drive rod segment492that extends through the proximal drive shaft segment380and the drive shaft assembly388. SeeFIG.13. The fifth drive system470includes a movable drive yoke472that is slidably supported on the tool mounting plate304. The proximal drive rod segment492is supported in the drive yoke372and has a pair of retainer balls394thereon such that shifting of the drive yoke372on the tool mounting plate304results in the axial movement of the proximal drive rod segment492. In at least one exemplary form, the fifth drive system370further includes a drive solenoid474that operably interfaces with the drive yoke472. The drive solenoid474receives control power from the robotic controller12. Actuation of the drive solenoid474in a first direction will cause the drive rod assembly490to move in the distal direction “DD” and actuation of the drive solenoid474in a second direction will cause the drive rod assembly490to move in the proximal direction “PD”. As can be seen inFIG.5, the end effector1000includes an anvil portion that is movable between open and closed positions upon application of axial closure motions to a closure system. In the illustrated embodiment ofFIGS.5and11-16, the fifth drive system470is employed to generate such closure motions. Thus, the fifth drive system470may also be referred to as a “closure drive”. The embodiment depicted inFIG.5, includes a surgical end effector1000that is attached to the tool mounting portion300by the elongate shaft assembly200. In that illustrated embodiment, the elongate shaft assembly includes a coupling arrangement in the form of a quick disconnect arrangement or joint210that facilitates quick attachment of a distal portion230of the shaft assembly200to a proximal shaft portion201of the shaft assembly200. The quick disconnect joint210serves to facilitate the quick attachment and detachment of a plurality of drive train components used to provide control motions from a source of drive motions to an end effector that is operably coupled thereto. In the embodiment illustrated inFIGS.5and19, for example, the quick disconnect joint210is employed to couple a distal shaft portion230of end effector1000to a proximal shaft portion201. Referring now toFIGS.19-23, the coupling arrangement or quick disconnect joint210includes a proximal coupler member212that is configured to operably support proximal drive train assemblies and a distal coupler member232that is configured to operably support at least one and preferably a plurality of distal drive train assemblies. In the embodiment ofFIGS.5and19, the third drive system430(i.e., a first articulation drive system) and the fourth drive system450(i.e., a second articulation drive system) are employed to apply articulation motions to the articulation joint700. For example, the third drive system430serves to apply control motions to the first proximal articulation cable434that has cable end portions434A,434B to articulate the end effector1000in first and second articulation directions about the articulation joint700. Likewise, the fourth drive system450serves to apply control motions to the second proximal articulation cable454that has cable end portions454A,454B to articulate the end effector1000in the third and fourth articulation directions. Referring toFIG.20, the proximal coupler member212has a first pair of diametrically-opposed first slots214therein and a second pair of diametrically-opposed second slots218therein (only one slot218can be seen inFIG.20). A first proximal articulation formation or link222is supported in each of the opposed first slots214. A second proximal articulation formation or link226is supported in each of the second slots218. The cable end portion434A extends through a slot in one of the proximal articulation links222and is attached thereto. Likewise, the cable end portion434B extends through a slot in the other proximal articulation link222and is attached thereto. Cable end portion434A and its corresponding proximal articulation formation or link222and cable end portion434B and its corresponding proximal articulation formation or link222are collectively referred to as a “first proximal articulation drive train assembly”217. The end cable portion454A extends through a slot in one of the proximal articulation links226and is attached thereto. The cable end portion454B extends through a slot in the other proximal articulation link226and is attached thereto. Cable end portion454A and its corresponding proximal articulation formation or link226and the cable end portion454B and its corresponding proximal articulation formation or link226are collectively referred to as a “second proximal articulation drive train assembly”221. As can be seen inFIG.21, the distal shaft portion230includes a distal outer tube portion231that supports the distal coupler member232. The distal coupler member232has a first pair of diametrically opposed first slots234therein and a second pair of diametrically opposed second slots238therein. SeeFIG.20. A first pair of distal articulation formations or links242are supported in the opposed first slots234. A second pair of distal articulation formations or links246are supported in the second pair of slots238. A first distal cable segment444extends through one of the first slots234and a slot in one of the distal articulation links242to be attached thereto. A primary distal cable segment445extends through the other one of the first slots234and through a slot in the other distal articulation link242and to be attached thereto. The first distal cable segment444and its corresponding distal articulation link242and the primary distal cable segment445and its corresponding distal articulation link242are collectively referred to as a “first distal articulation drive train assembly”237. A second distal cable segment446extends through one of the second slots238and a slot in one of the distal articulation links246and to be attached thereto. A secondary distal cable segment447extends through the other second slot238and through a slot in the other distal articulation link246to be attached thereto. The second distal cable segment446and its corresponding distal articulation link246and the secondary distal cable segment447and its corresponding distal articulation link246are collectively referred to as a “second distal articulation drive train assembly”241. Each of the proximal articulation links222has a toothed end224formed on a spring arm portion223thereof. Each proximal articulation link226has a toothed end227′ formed on a spring arm portion227. Each distal articulation link242has a toothed end243that is configured to be meshingly coupled with the toothed end224of a corresponding one of the proximal articulation links222. Each distal articulation link246has a toothed end247that is configured to be meshingly coupled with the toothed end228of a corresponding proximal articulation link226. When the proximal articulation formations or links222,226are meshingly linked with the distal articulation links242,246, respectively, the first and second proximal articulation drive train assemblies217and221are operably coupled to the first and second distal articulation drive train assemblies237and241, respectively. Thus, actuation of the third and fourth drive systems430,450will apply actuation motions to the distal cable segments444,445,446,447as will be discussed in further detail below. In the embodiment ofFIGS.19-23, a distal end250of proximal outer tube segment202has a series of spring fingers252therein that extend distally into slots254configured to receive corresponding spring arm portions223,227therein. SeeFIG.21(spring arm portion227is not depicted inFIG.21but can be seen inFIG.20). Each spring finger252has a detent256therein that is adapted to engage corresponding dimples258formed in the proximal articulation links222,226when the proximal articulation links222,226are in the neutral position (FIG.23). When the clinician desires to remove or attach an end effector1000to the proximal shaft portion201, the third and fourth drive systems430,450are parked in their neutral unactuated positions. The proximal coupler member212and the distal coupler member232of the quick disconnect joint210operably support corresponding portions of a drive member coupling assembly500for releasably coupling the proximal drive rod segment492to a distal drive rod segment520. The proximal drive rod segment492comprises a proximal axial drive train assembly496and the distal drive rod segment520comprises a distal axial drive train assembly528. The drive member coupling assembly500comprises a drive rod coupler or formation502that comprises a receiving formation or first magnet504such as, for example, a rare earth magnet, etc. that is attached to the distal end493of the distal drive rod segment520. The first magnet504has a receiving cavity506formed therein for receiving a second formation or distal magnet510. As can be seen inFIG.21, the distal magnet510is attached to a tapered mounting member512that is attached to a proximal end522of the distal drive rod520. The proximal coupler member212and the distal coupler member232of the quick disconnect joint210operably support other corresponding portions of a drive member coupling assembly500for releasably coupling the proximal drive shaft segment380with a distal drive shaft segment540. The proximal drive shaft segment380, in at least one exemplary form, comprises a proximal rotary drive train assembly387and the distal drive shaft segment540comprises a distal rotary drive train assembly548. When the proximal rotary drive train assembly387is operably coupled to the distal rotary drive train assembly548, the drive shaft assembly388is formed to transmit rotary control motions to the end effector1000. In the illustrated exemplary embodiment, a proximal end542of the distal drive shaft segment540has a plurality (e.g., four—only two can be seen inFIG.21) formations or cleated fingers544formed thereon. Each cleated finger544has an attachment cleat546formed thereon that are sized to be received in corresponding lock formations or holes or slots383in a distal end381of the proximal drive shaft segment380. The fingers544extend through a reinforcing ring545journaled onto the proximal end542of the distal drive shaft segment540. In the embodiment depicted inFIGS.19-23, the drive member coupling assembly500further includes an unlocking tube514for assisting in the disengagement of the first and second magnets504,510when the clinician detaches the end effector1000from the proximal shaft portion201of the surgical tool100. The unlocking tube514extends through the proximal drive shaft segment380and its proximal end517protrudes out of the proximal end385of the proximal drive shaft segment380as shown inFIG.19. The unlocking tube514is sized relative to the proximal drive shaft segment380so as to be axially movable therein upon application of an unlocking motion “UL” applied to the proximal end517thereof. A handle (not shown) is attached to the proximal end517of the unlocking tube to facilitate the manual application of the unlocking motion “UL” to the unlocking tube514or the unlocking motion “UL”. Other embodiments that are otherwise identical to the embodiment ofFIGS.19-23employ an unlocking solenoid (not shown) that is attached to the tool mounting plate304and powered by the robotic controller12or a separate battery attached thereto is employed to apply the unlocking motion. In the illustrated exemplary embodiment, the coupling arrangement or quick disconnect joint210also includes an outer lock collar260that is slidably journaled on the distal end204of the proximal outer tube portion202. The outer lock collar260has four inwardly extending detents262that extend into a corresponding one of the slots254in the proximal outer tube portion202. Use of the quick disconnect joint210can be understood from reference toFIGS.21-23.FIG.21illustrates the conditions of the proximal shaft portion201and the distal shaft portion230prior to being coupled together. As can be seen in that Figure, the spring arm portions223,227of the proximal articulation links224,226, respectively are naturally radially sprung outward. The locking collar260is moved to its proximal-most position on the proximal outer tube202wherein the detents262are at the proximal end of the slots254therein. When the clinician desires to attach the end effector1000to the proximal shaft portion201of the surgical tool100, the clinician brings the distal shaft portion230into axial alignment and coupling engagement with the proximal shaft portion201as shown inFIG.22. As can be seen in that Figure, the distal magnet510is seated within the cavity506in the drive rod coupler502and is magnetically attached to the proximal magnet504to thereby couple the distal drive rod segment520to the proximal drive rod segment492. Such action thereby operably couples the distal axial drive train assembly528to the proximal axial drive train assembly496. In addition, as the shaft portions201,230are joined together, the cleated fingers544flex inward until the cleats546formed thereon enter the lock openings383in the distal end portion381of the proximal drive shaft segment380. When the cleats546are seated within their respective locking holes383, the distal drive shaft segment540is coupled to the proximal drive shaft segment380. Thus, such action thereby operably couples the distal rotary drive train assembly548to the proximal rotary drive train assembly387. As such, when distal coupler member232and the proximal coupler member212are brought into axial alignment and engagement in the manner described above and the locking collar260is moved to its proximal-most position on the proximal outer tube202, the distal drive train assemblies are operably coupled to the proximal drive train assemblies. When the clinician desires to detach the end effector1000from the proximal shaft portion201of the surgical tool100, the clinician returns the third and fourth drive systems430,450into their neutral positions. The clinician may then slide the locking collar260proximally on the proximal outer tube segment202into the starting position shown inFIG.22. When in that position, the spring arm portions of the proximal articulation links222,226cause the toothed portions thereof to disengage the toothed portions of the distal articulation links242,246. The clinician may then apply an unlocking motion UL to the proximal end517of the unlocking tube514to move the unlocking tube514and the unlocking collar516attached thereto in the distal direction “DD”. As the unlocking collar516moves distally, it biases the cleated fingers544out of engagement with their respective holes383in the distal end portion381of the proximal drive shaft segment380and contacts the tapered mounting portion512to force the distal magnet510out of magnetic engagement with the proximal magnet504. FIGS.22A,23A and23Bdepict an alternative coupling arrangement or quick disconnect joint assembly210″ that is similar to the quick disconnect joint210described above except that an electromagnet504′ is employed to couple the distal drive rod segment520to the proximal drive rod segment492′. As can be seen in these Figures, the proximal drive rod segment492′ is hollow to accommodate conductors505that extend from a source of electrical power in the robotic system10. The conductors505are wound around a piece of iron508. When the clinician brings the distal shaft portion230into engagement with the proximal shaft portion201as shown inFIG.22A, electrical current may be passed through the conductors505in a first direction to cause the magnet504′ to attract the magnet510into coupling engagement as shown inFIG.23A. When the clinician desires to detach the end effector1000from the proximal shaft portion201of the surgical tool100, the clinician returns the third and fourth drive systems430,450into their neutral positions. The clinician may then slide the locking collar260proximally on the proximal outer tube segment202into the starting position shown inFIG.22A. When in that position, the spring arm portions of the proximal articulation links222,226cause the toothed portions thereof to disengage the toothed portions of the distal articulation links242,246. The clinician may then apply an unlocking motion UL to the proximal end517of the unlocking tube514to move the unlocking tube514and the unlocking collar516attached thereto in the distal direction “DD”. In addition, the electrical current may be passed through the conductors505in an opposite direction to cause the electromagnet504′ to repel magnet510to assist in separating the shaft segments. As the clinician moves the unlocking tube distally, the unlocking collar516biases the cleated fingers544out of engagement with their respective holes383in the distal end portion381of the proximal drive shaft segment380and contacts the tapered mounting portion512to further separate the shaft segments. The coupling arrangements or quick detach joint assemblies described above may offer many advantages. For example, such arrangements may employ a single release/engagement motions that cannot be left semi-engaged. Such engagement motions can be employed to simultaneously operably couple several drive train assemblies wherein at least some drive train assemblies provide control motions that differ from the control motions provided by other drive train assemblies. For example, some drive trains may provide rotary control motions and be longitudinally shiftable to provide axial control motions and some may just provide rotary or axial control motions. Other drive train assemblies may provide push/pull motions for operating various end effector systems/components. The unique and novel locking collar arrangement ensures that either the distal drive train assemblies are locked to their respective proximal drive train assemblies or they are unlocked and may be detached therefrom. When locked together, all of the drive train assemblies are radially supported by the locking collar which prevents any uncoupling. The surgical tool100depicted inFIGS.5and11-16includes an articulation joint700that cooperates with the third and fourth drive systems430,450, respectively for articulating the end effector1000about the longitudinal tool axis “LT”. The articulation joint700includes a proximal socket tube702that is attached to the distal end233of the distal outer tube portion231and defines a proximal ball socket704therein. SeeFIG.25. A proximal ball member706is movably seated within the proximal ball socket704. As can be seen inFIG.25, the proximal ball member706has a central drive passage708that enables the distal drive shaft segment540to extend therethrough. In addition, the proximal ball member706has four articulation passages710therein which facilitate the passage of distal cable segments444,445,446,447therethrough. As can be further seen inFIG.25, the articulation joint700further includes an intermediate articulation tube segment712that has an intermediate ball socket714formed therein. The intermediate ball socket714is configured to movably support therein an end effector ball722formed on an end effector connector tube720. The distal cable segments444,445,446,447extend through cable passages724formed in the end effector ball722and are attached thereto by lugs726received within corresponding passages728in the end effector ball722. Other attachment arrangements may be employed for attaching distal cable segments444,445,446,447to the end effector ball722. A unique and novel rotary support joint assembly, generally designated as740, is depicted inFIGS.26and27. The illustrated rotary support joint assembly740includes a connector portion1012of the end effector drive housing1010that is substantially cylindrical in shape. A first annular race1014is formed in the perimeter of the cylindrically-shaped connector portion1012. The rotary support joint assembly740further comprises a distal socket portion730that is formed in the end effector connector tube720as shown inFIGS.26and27. The distal socket portion730is sized relative to the cylindrical connector portion1012such that the connector portion1012can freely rotate within the socket portion730. A second annular race732is formed in an inner wall731of the distal socket portion730. A window733is provided through the distal socket730that communicates with the second annular race732therein. As can also be seen inFIGS.26and27, the rotary support joint assembly740further includes a ring-like bearing734. In various exemplary embodiments, the ring-like bearing734comprises a plastic deformable substantially-circular ring that has a cut735therein. The cut forms free ends736,737in the ring-like bearing734. As can be seen inFIG.26, the ring-like bearing734has a substantially annular shape in its natural unbiased state. To couple a surgical end effector1000(e.g., a first portion of a surgical instrument) to the articulation joint700(e.g., a second portion of a surgical instrument), the cylindrically shaped connector position1012is inserted into the distal socket portion730to bring the second annular race732into substantial registry with the first annular race1014. One of the free ends736,737of the ring-like bearing is then inserted into the registered annular races1014,732through the window733in the distal socket portion730of the end effector connector tube720. To facilitate easy insertion, the window or opening733has a tapered surface738formed thereon. SeeFIG.26. The ring-like bearing734is essentially rotated into place and, because it tends to form a circle or ring, it does not tend to back out through the window733once installed. Once the ring-like bearing734has been inserted into the registered annular races1014,732, the end effector connector tube720will be rotatably affixed to the connector portion1012of the end effector drive housing1010. Such arrangement enables the end effector drive housing1010to rotate about the longitudinal tool axis LT-LT relative to the end effector connector tube720. The ring-like bearing734becomes the bearing surface that the end effector drive housing1010then rotates on. Any side loading tries to deform the ring-like bearing734which is supported and contained by the two interlocking races1014,732preventing damage to the ring-like bearing734. It will be understood that such simple and effective joint assembly employing the ring-like bearing734forms a highly lubricious interface between the rotatable portions1010,730. If during assembly, one of the free ends736,737is permitted to protrude out through the window733(see e.g.,FIG.27), the rotary support joint assembly740may be disassembled by withdrawing the ring-like bearing member732out through the window733. The rotary support joint assembly740allows for easy assembly and manufacturing while also providing for good end effector support while facilitating rotary manipulation thereof. The articulation joint700facilitates articulation of the end effector1000about the longitudinal tool axis LT. For example, when it is desirable to articulate the end effector1000in a first direction “FD” as shown inFIG.5, the robotic system10may power the third drive system430such that the third drive spindle assembly436(FIGS.11-13) is rotated in a first direction thereby drawing the proximal cable end portion434A and ultimately distal cable segment444in the proximal direction “PD” and releasing the proximal cable end portion434B and distal cable segment445to thereby cause the end effector ball722to rotate within the socket714. Likewise, to articulate the end effector1000in a second direction “SD” opposite to the first direction FD, the robotic system10may power the third drive system430such that the third drive spindle assembly436is rotated in a second direction thereby drawing the proximal cable end portion434B and ultimately distal cable segment445in the proximal direction “PD” and releasing the proximal cable end portion434A and distal cable segment444to thereby cause the end effector ball722to rotate within the socket714. When it is desirable to articulate the end effector1000in a third direction “TD” as shown inFIG.5, the robotic system10may power the fourth drive system450such that the fourth drive spindle assembly456is rotated in a third direction thereby drawing the proximal cable end portion454A and ultimately distal cable segment446in the proximal direction “PD” and releasing the proximal cable end portion454B and distal cable segment447to thereby cause the end effector ball722to rotate within the socket714. Likewise, to articulate the end effector1000in a fourth direction “FTH” opposite to the third direction TD, the robotic system10may power the fourth drive system450such that the fourth drive spindle assembly456is rotated in a fourth direction thereby drawing the proximal cable end portion454B and ultimately distal cable segment447in the proximal direction “PD” and releasing the proximal cable end portion454A and distal cable segment446to thereby cause the end effector ball722to rotate within the socket714. The end effector embodiment depicted inFIGS.5and11-16employs rotary and longitudinal motions that are transmitted from the tool mounting portion300through the elongate shaft assembly for actuation. The drive shaft assembly employed to transmit such rotary and longitudinal motions (e.g., torsion, tension and compression motions) to the end effector is relatively flexible to facilitate articulation of the end effector about the articulation joint.FIGS.28and29illustrate an alternative drive shaft assembly600that may be employed in connection with the embodiment illustrated inFIGS.5and11-16or in other embodiments. In the embodiment depicted inFIG.5which employs the quick disconnect joint210, the proximal drive shaft segment380comprises a segment of drive shaft assembly600and the distal drive shaft segment540similarly comprises another segment of drive shaft assembly600. The drive shaft assembly600includes a drive tube602that has a series of annular joint segments604cut therein. In that illustrated embodiment, the drive tube602comprises a distal portion of the proximal drive shaft segment380. The drive tube602comprises a hollow metal tube (stainless steel, titanium, etc.) that has a series of annular joint segments604formed therein. The annular joint segments604comprise a plurality of loosely interlocking dovetail shapes606that are, for example, cut into the drive tube602by a laser and serve to facilitate flexible movement between the adjoining joint segments604. SeeFIG.29. Such laser cutting of a tube stock creates a flexible hollow drive tube that can be used in compression, tension and torsion. Such arrangement employs a full diametric cut that is interlocked with the adjacent part via a “puzzle piece” configuration. These cuts are then duplicated along the length of the hollow drive tube in an array and are sometimes “clocked” or rotated to change the tension or torsion performance. FIGS.30-34illustrate alternative exemplary micro-annular joint segments604′ that comprise plurality of laser cut shapes606′ that roughly resemble loosely interlocking, opposed “T” shapes and T-shapes with a notched portion therein. The annular joint segments604,604′ essentially comprise multiple micro-articulating torsion joints. That is, each joint segment604,604′ can transmit torque while facilitating relative articulation between each annular joint segment. As shown inFIGS.30and31, the joint segment604D′ on the distal end603of the drive tube602has a distal mounting collar portion608D that facilitates attachment to other drive components for actuating the end effector or portions of the quick disconnect joint, etc. and the joint segment604P′ on the proximal end605of the drive tube602has a proximal mounting collar portion608P′ that facilitates attachment to other proximal drive components or portions of the quick disconnect joint. The joint-to-joint range of motion for each particular drive shaft assembly600can be increased by increasing the spacing in the laser cuts. For example, to ensure that the joint segments604′ remain coupled together without significantly diminishing the drive tube's ability to articulate through desired ranges of motion, a secondary constraining member610is employed. In the embodiment depicted inFIGS.32and33, the secondary constraining member610comprises a spring612or other helically-wound member. In various exemplary embodiments, the distal end614of the spring612corresponds to the distal mounting collar portion608D and is wound tighter than the central portion616of the spring612. Similarly, the proximal end618of the spring612is wound tighter than the central portion616of the spring612. In other embodiments, the constraining member610is installed on the drive tube602with a desired pitch such that the constraining member also functions, for example, as a flexible drive thread for threadably engaging other threaded control components on the end effector and/or the control system. It will also be appreciated that the constraining member may be installed in such a manner as to have a variable pitch to accomplish the transmission of the desired rotary control motions as the drive shaft assembly is rotated. For example, the variable pitch arrangement of the constraining member may be used to enhance open/close and firing motions which would benefit from differing linear strokes from the same rotation motion. In other embodiments, for example, the drive shaft assembly comprises a variable pitch thread on a hollow flexible drive shaft that can be pushed and pulled around a ninety degree bend. In still other embodiments, the secondary constraining member comprises an elastomeric tube or coating611applied around the exterior or perimeter of the drive tube602as illustrated inFIG.34A. In still another embodiment, for example, the elastomeric tube or coating611′ is installed in the hollow passageway613formed within the drive tube602as shown inFIG.34B. Such drive shaft arrangements comprise a composite torsional drive axle which allows superior load transmission while facilitating a desirable axial range of articulation. See, e.g.,FIGS.34and34A-B. That is, these composite drive shaft assemblies allow a large range of motion while maintaining the ability to transmit torsion in both directions as well as facilitating the transmission of tension and compression control motions therethrough. In addition, the hollow nature of such drive shaft arrangements facilitate passage of other control components therethrough while affording improved tension loading. For example, some other embodiments include a flexible internal cable that extends through the drive shaft assembly which can assist in the alignment of the joint segments while facilitating the ability to apply tension motions through the drive shaft assembly. Moreover, such drive shaft arrangements are relatively easily to manufacture and assemble. FIGS.35-38depict a segment620of a drive shaft assembly600′. This embodiment includes joint segments622,624that are laser cut out of tube stock material (e.g., stainless steel, titanium, polymer, etc.). The joint segments622,624remain loosely attached together because the cuts626are radial and are somewhat tapered. For example, each of the lug portions628has a tapered outer perimeter portion629that is received within a socket630that has a tapered inner wall portion. See, e.g.,FIGS.36and38. Thus, there is no assembly required to attach the joint segments622,624together. As can be seen in the Figures, joint segment622has opposing pivot lug portions628cut on each end thereof that are pivotally received in corresponding sockets630formed in adjacent joint segments624. FIGS.35-38illustrate a small segment of the drive shaft assembly600′. Those of ordinary skill in the art will appreciate that the lugs/sockets may be cut throughout the entire length of the drive shaft assembly. That is, the joint segments624may have opposing sockets630cut therein to facilitate linkage with adjoining joint segments622to complete the length of the drive shaft assembly600′. In addition, the joint segments624have an angled end portion632cut therein to facilitate articulation of the joint segments624relative to the joint segments622as illustrated inFIGS.37and38. In the illustrated embodiment, each lug628has an articulation stop portion634that is adapted to contact a corresponding articulation stop636formed in the joint segment622. SeeFIGS.37and38. Other embodiments, which may otherwise be identical to the segment620, are not provided with the articulation stop portions634and stops636. As indicated above, the joint-to-joint range of motion for each particular drive shaft assembly can be increased by increasing the spacing in the laser cuts. In such embodiments, to ensure that the joint segments622,624remain coupled together without significantly diminishing the drive tube's ability to articulate through desired ranges of motion, a secondary constraining member in the form of an elastomeric sleeve or coating640is employed. Other embodiments employ other forms of constraining members disclosed herein and their equivalent structures. As can be seen inFIG.35, the joint segments622,624are capable of pivoting about pivot axes “PA-PA” defined by the pivot lugs628and corresponding sockets630. To obtain an expanded range of articulation, the drive shaft assembly600′ may be rotated about the tool axis TL-TL while pivoting about the pivot axes PA-PA. FIGS.39-44depict a segment640of another drive shaft assembly600″. The drive shaft assembly600″ comprises a multi-segment drive system that includes a plurality of interconnected joint segments642that form a flexible hollow drive tube602″. A joint segment642includes a ball connector portion644and a socket portion648. Each joint segment642may be fabricated by, for example, metal injection molding “MIM” and be fabricated from 17-4, 17-7, 420 stainless steel. Other embodiments may be machined from 300 or 400 series stainless steel, 6065 Or 7071 aluminum or titanium. Still other embodiments could be molded out of plastic infilled or unfilled Nylon, Ultem, ABS, Polycarbonate or Polyethylene, for example. As can be seen in the Figures, the ball connector644is hexagonal in shape. That is, the ball connector644has six arcuate surfaces646formed thereon and is adapted to be rotatably received in like-shaped sockets650. Each socket650has a hexagonally-shaped outer portion652formed from six flat surfaces654and a radially-shaped inner portion656. SeeFIG.42. Each joint segment642is identical in construction, except that the socket portions of the last joint segments forming the distal and proximal ends of the drive shaft assembly600may be configured to operably mate with corresponding control components. Each ball connector644has a hollow passage645therein that cooperate to form a hollow passageway603through the hollow flexible drive tube602″. As can be seen inFIGS.43and44, the interconnected joint segments642are contained within a constraining member660which comprises a tube or sleeve fabricated from a flexible polymer material, for example.FIG.45illustrates a flexible inner core member662extending through the interconnected joint segments642. The inner core member662comprises a solid member fabricated from a polymer material or a hollow tube or sleeve fabricated from a flexible polymer material.FIG.46illustrates another embodiment wherein a constraining member660and an inner core member662are both employed. Drive shaft assembly600″ facilitates transmission of rotational and translational motion through a variable radius articulation joint. The hollow nature of the drive shaft assembly600″ provides room for additional control components or a tensile element (e.g., a flexible cable) to facilitate tensile and compressive load transmission. In other embodiments, however, the joint segments624do not afford a hollow passage through the drive shaft assembly. In such embodiments, for example, the ball connector portion is solid. Rotary motion is translated via the edges of the hexagonal surfaces. Tighter tolerances may allow greater load capacity. Using a cable or other tensile element through the centerline of the drive shaft assembly600″, the entire drive shaft assembly600″ can be rotated bent, pushed and pulled without limiting range of motion. For example, the drive shaft assembly600″ may form an arcuate drive path, a straight drive path, a serpentine drive path, etc. FIGS.5and47-54illustrate one surgical end effector1000that may be effectively employed with the robotic system10. The end effector1000comprises an endocutter1002that has a first jaw1004and a second jaw1006that is selectively movable relative to the first jaw1004. In the embodiment illustrated inFIGS.5and47-54, the first jaw1004comprises a support member1019in the form of an elongate channel1020that is configured to operably support a staple cartridge1030therein. The second jaw1006comprises an anvil assembly1100. As can be seen inFIGS.47,49,53and55, the anvil assembly1100comprises an anvil body1102that has a staple forming surface1104thereon. The anvil body1102has a passage1106that is adapted to register with mounting holes1022in the elongate channel1020. A pivot or trunnion pin (not shown) is inserted through the holes1022and passage1104to pivotally couple the anvil1100to the elongate channel1020. Such arrangement permits the anvil assembly1100to be selectively pivoted about a closure axis “CA-CA” that is substantially transverse to the longitudinal tool axis “LT-LT” (FIG.48) between an open position wherein the staple forming surface1104is spaced away from the cartridge deck1044of the staple cartridge1040(FIGS.47-50) and closed positions (FIGS.51-54) wherein the staple forming surface1104on the anvil body1102is in confronting relationship relative to the cartridge deck1042. The embodiment ofFIGS.5and47-54employs a closure assembly1110that is configured to receive opening and closing motions from the fifth drive system470. The fifth drive system470serves to axially advance and retract a drive rod assembly490. As described above, the drive rod assembly490includes a proximal drive rod segment492that operably interfaces with the drive solenoid474to receive axial control motions therefrom. The proximal drive rod segment492is coupled to a distal drive rod segment520through the drive rod coupler502. The distal drive rod segment520is somewhat flexible to facilitate articulation of the end effector1000about articulation joint700yet facilitate the axial transmission of closing and opening motions therethrough. For example, the distal drive rod segment520may comprise a cable or laminate structure of titanium, stainless spring steel or Nitinol. The closure assembly1110includes a closure linkage1112that is pivotally attached to the elongate channel1020. As can be seen inFIGS.48,51and52, the closure linkage1112has an opening1114therein through which the distal end524of the distal drive rod segment520extends. A ball526or other formation is attached to the distal drive rod segment520to thereby attach the distal end524of the distal drive rod segment520to the closure linkage1112. The closure assembly1110further includes a pair of cam discs1120that are rotatably mounted on the lateral sides of the elongate channel1020. One cam disc1120is rotatably supported on one lateral side of the elongate channel1020and the other cam disc1120is rotatably supported to the other lateral side of the elongate channel1020. SeeFIG.60. A pair of pivot links1122are attached between each cam disc1120and the closure linkage1112. Thus, pivotal travel of the closure linkage1112by the drive rod assembly490will result in the rotation of the cam discs1120. Each cam disc1120further has an actuator pin1124protruding therefrom that is slidably received in a corresponding cam slot1108in the anvil body1102. Actuation of the second jaw1006or anvil assembly1100will now be described.FIGS.47-50illustrate the anvil assembly1100in the open position. After the end effector1000has been positioned relative to the tissue to be cut and stapled, the robotic controller12may activate the drive solenoid474in the first or distal direction “DD” which ultimately results in the distal movement of the drive yoke472which causes the drive rod assembly490to move in the distal direction “DD”. Such movement of the drive rod assembly490results in the distal movement of the distal drive rod segment520which causes the closure linkage1112to pivot from the open position to the closed position (FIGS.51-54). Such movement of the closure linkage1112causes the cam discs1120to rotate in the “CCW” direction. As the cam discs rotate in the “CCW” direction, interaction between the actuator pins1124and their respective cam slot1108causes the anvil assembly1100to pivot closed onto the target tissue. To release the target tissue, the drive solenoid474is activated to pull the drive rod assembly490in the proximal direction “PD” which results in the reverse pivotal travel of the closure linkage1112to the open position which ultimately causes the anvil assembly1100to pivot back to the open position. FIGS.55-59illustrate another closure system670for applying opening and closing motions to the anvil1100. As can be seen inFIG.56, for example, the closure system670includes a first mounting block or member672that rotatably supports a first closure rod segment680. The first closure rod segment680has a substantially semi-circular, cross-sectional shape. A proximal end682of the first closure rod segment680has a first ball connector684thereon that is rotatably supported within a first mounting socket673formed in the mounting block672. To facilitate articulation of the end effector1000by the articulation joint700, the first closure rod segment680also has a first serrated portion686that coincides with the articulation joint700as illustrated inFIGS.58and59. The closure system670further includes a second mounting block or member674that rotatably supports a second closure rod segment690. The second closure rod segment690has a substantially semi-circular, cross-sectional shape. A proximal end692of the second closure rod segment690has a second ball connector694thereon that is rotatably supported within a second mounting socket675formed in the second mounting block674. To facilitate articulation of the end effector1000by the articulation joint700, the second closure rod segment690also has a second serrated portion696that coincides with the articulation joint700as illustrated inFIGS.58and59. As can also be seen inFIG.56, the closure system670further has a first pivot link676that is attached to a distal end682of the first closure rod segment680. The first pivot link676has a first pivot lug677formed thereon that is configured to be rotatably supported within a first socket683formed in the distal end682of the first closure rod segment680. Such arrangement permits the first pivot link676to rotate relative to the first closure rod segment680. Likewise, a second pivot link678is attached to a distal end691of the second closure rod segment690such that it can rotate relative thereto. The second pivot link678has a second pivot lug1679formed thereon that is configured to extend through an opening in the first pivot lug677to be rotatably supported within a second socket692in a distal end1691of the second closure rod segment690. In addition, as can be seen inFIG.56, the first and second pivot links676,678are movably keyed to each other by a key716on the second pivot link678that is slidably received within a slot717in the first pivot link676. In at least one embodiment, the first pivot link676is attached to each of the cam discs1120by first linkage arms687and the second pivot link678is attached to each of the cam discs1120by second linkage arms688. In the illustrated embodiment, the closure system670is actuated by the drive solenoid474. The drive solenoid474is configured to operably interface with one of the first and second mounting blocks672,674to apply axial closing and opening motions thereto. As can be seen inFIGS.56-59, such drive arrangement may further comprise a first pivot link and gear assembly695that is movably attached to the first mounting block672by a pin685that extends into a slot696in the first pivot link and gear assembly695. Similarly, a second pivot link and gear assembly697is movably attached to the second mounting block674by a pin685that extends into a slot698in the second pivot link and gear assembly697. The first pivot link and gear assembly695has a first bevel gear699A rotatably mounted thereto and the second pivot link and gear assembly697has a second bevel gear699B rotatably attached thereto. Both first and second bevel gears699A,699B are mounted in meshing engagement with an idler gear689rotatably mounted on the tool mounting plate302. SeeFIG.59A. Thus, when the first mounting block672is advanced in the distal direction “DD” which also results in the movement of the first closure rod segment680and first pivot link676in the distal direction DD, the bevel gears689,699A,699B will result in the movement of the second closure rod690and second pivot link678in the proximal direction “PD”. Likewise, when the first mounting block672is advanced in the proximal direction “PD” which also results in the movement of the first closure rod segment680and first pivot link676in the proximal direction PD, the bevel gears689,699A,699B will result in the movement of the second closure rod690and second pivot link678in the distal direction “DD”. FIG.58illustrates the anvil1100in the open position. As can be seen in that Figure, the first closure rod680is slightly proximal to the second closure rod690. To close the anvil, the drive solenoid474is powered to axially advance the first closure rod680in the distal direction “DD”. Such action causes the first pivot link676and first linkage arms687to rotate the cam discs1120in the counter-clockwise “CCW” direction as shown inFIG.59. Such motion also results in the movement of the second closure rod690is the proximal direction causing the second pivot link678and second linkage arms688to also pull the cam discs1120in the counter-clockwise “CCW” direction. To open the anvil, the drive solenoid474applies an axial control motion to the first mounting block672to return the first and second control rod segments680,690to the positions shown inFIG.58. The end effector embodiment1000illustrated inFIG.60includes a drive arrangement generally designated as748that facilitates the selective application of rotary control motions to the end effector1000. The end effector1000includes a firing member1200that is threadably journaled on an implement drive shaft1300. As can be seen inFIG.61, the implement drive shaft1300has a bearing segment1304formed thereon that is rotatably supported in a bearing sleeve1011. The implement drive shaft1300has an implement drive gear1302that operably meshes with a rotary transmission generally designated as750that operably interfaces with the elongate channel1020and is operably supported by a portion of the elongate shaft assembly200. In one exemplary form, the rotary transmission750includes a differential interlock assembly760. As can be seen inFIGS.64and65, the differential interlock assembly760includes a differential housing762that is configured to selectively rotate relative to the end effector drive housing1010and to rotate with the end effector housing1010. The distal drive shaft segment540is attached to a sun gear shaft752that has a sun gear754attached thereto. Thus, sun gear754will rotate when the distal drive shaft segment540is rotated. Sun gear754will also move axially with the distal drive shaft segment540. The differential interlock assembly760further includes a plurality of planet gears764that are rotatably attached to the differential housing762. In at least one embodiment, for example, three planet gears764are employed. Each planet gear764is in meshing engagement with a first end effector ring gear1016formed within the end effector drive housing1010. In the illustrated exemplary embodiment shown inFIG.60, the end effector drive housing1010is non-rotatably attached to the elongate channel1020by a pair of opposing attachment lugs1018(only one attachment lug1018can be seen inFIG.60) into corresponding attachment slots1024(only one attachment slot1024can be seen inFIG.60) formed in the proximal end1021of the elongate channel1020. Other methods of non-movably attaching the end effector drive housing1010to the elongate channel1020may be employed or the end effector drive housing1010may be integrally formed with the elongate channel1020. Thus, rotation of the end effector drive housing1010will result in the rotation of the elongate channel1020of the end effector1000. In the embodiment depicted inFIGS.61-65, the differential interlock assembly760further includes a second ring gear766that is formed within the differential housing762for meshing engagement with the sun gear754. The differential interlock assembly760also includes a third ring gear768formed in the differential housing762that is in meshing engagement with the implement drive gear1302. Rotation of the differential housing762within the end effector drive housing1010will ultimately result in the rotation of the implement drive gear1302and the implement drive shaft1300attached thereto. When the clinician desires to rotate the end effector1000about the longitudinal tool axis LT-LT distal to the articulation joint700to position the end effector in a desired orientation relative to the target tissue, the robotic controller12may activate the shifter solenoid394to axially move the proximal drive shaft segment380such that the sun gear754is moved to a “first axial” position shown inFIGS.65,67and70. As described in detail above, the distal drive shaft segment540is operably coupled to the proximal drive shaft segment380by the quick disconnect joint210. Thus, axial movement of the proximal drive shaft segment380may result in the axial movement of the distal drive shaft segment540and the sun gear shaft752and sun gear754. As was further described above, the shifting system390controls the axial movement of the proximal drive shaft segment380. When in the first axial position, the sun gear754is in meshing engagement with the planetary gears764and the second ring gear766to thereby cause the planetary gears764and the differential housing762to rotate as a unit as the sun gear754is rotated. Rotation of the proximal drive shaft segment380is controlled by the second drive system370. Rotation of the proximal drive shaft segment380results in rotation of the distal drive shaft segment540, the sun gear shaft752and sun gear754. Such rotation of the differential housing762and planetary gears764as a unit applies a rotary motion to the end effector drive housing1010of sufficient magnitude to overcome a first amount of friction F1 between the end effector drive housing1010and the distal socket portion730of the intermediate articulation tube712to thereby cause the end effector drive housing1010and end effector1000attached thereto to rotate about the longitudinal tool axis “LT-LT” relative to the distal socket tube730. Thus, when in such position, the end effector drive housing1010, the differential housing762and the planetary gears764all rotate together as a unit. Because the implement shaft1300is supported by the bearing sleeve1011in the end effector drive housing, the implement shaft1300also rotates with the end effector drive housing1010. SeeFIG.61. Thus, rotation of the end effector drive housing1010and the end effector1000does not result in relative rotation of the implement drive shaft1300which would result in displacement of the firing member1200. In the illustrated exemplary embodiment, such rotation of the end effector1000distal of the articulation joint700does not result in rotation of the entire elongate shaft assembly200. When it is desired to apply a rotary drive motion to the implement drive shaft1300for driving the firing member1200within the end effector1000, the sun gear754is axially positioned in a “second axial” position to disengage the second ring gear766while meshingly engaging the planetary gears764as shown inFIGS.61,62,64and66. Thus, when it is desired to rotate the implement drive shaft1300, the robotic controller12activates the shifter solenoid394to axially position the sun gear754into meshing engagement with the planetary gears764. When in that second axial or “firing position”, the sun gear754only meshingly engages the planetary gears764. Rotation of the proximal drive shaft segment380may be controlled by the second drive system370. Rotation of the proximal drive shaft segment380results in rotation of the distal drive shaft segment540, the sun gear shaft752and sun gear754. As the sun gear754is rotated in a first firing direction, the planetary gears764are also rotated. As the planetary gears764rotate, they also cause the differential housing762to rotate. Rotation of the differential housing762causes the implement shaft1300to rotate due to the meshing engagement of the implement drive gear1302with the third ring gear768. Because of the amount of friction F1 existing between the end effector drive housing1010and the distal socket portion730of the intermediate articulation tube712, rotation of the planetary gears764does not result in the rotation of the end effector housing1010relative to the intermediate articulation tube712. Thus, rotation of the drive shaft assembly results in rotation of the implement drive shaft1300without rotating the entire end effector1000. Such unique and novel rotary transmission750comprises a single drive system that can selectively rotate the end effector1000or fire the firing member1200depending upon the axial position of the rotary drive shaft. One advantage that may be afforded by such arrangement is that it simplifies the drives that must transverse the articulation joint700. It also translates the central drive to the base of the elongate channel1020so that the implement drive shaft1300can exist under the staple cartridge1040to the drive the firing member1200. The ability for an end effector to be rotatable distal to the articulation joint may vastly improve the ability to position the end effector relative to the target tissue. As indicated above, when the drive shaft assembly is positioned in a first axial position, rotation of the drive shaft assembly may result in rotation of the entire end effector1000distal of the articulation joint700. When the drive shaft assembly is positioned in a second axial position (in one example-proximal to the first axial position), rotation of the drive shaft assembly may result in the rotation of the implement drive shaft1300. The rotary transmission embodiment depicted inFIGS.64and65includes a differential locking system780which is configured to retain the drive shaft assembly in the first and second axial positions. As can be seen inFIGS.64and65, the differential locking system780comprises a first retention formation756in the sun gear shaft752that corresponds to the first axial position of the drive shaft assembly and a second retention formation758in the sun gear shaft752that correspond to the second axial position of the drive shaft assembly. In the illustrated exemplary embodiment, the first retention formation comprises a first radial locking groove757in the sun gear shaft752and the second retention formation758comprises a second radial locking groove759formed in the sun gear shaft752. The first and second locking grooves757,759cooperate with at least one spring-biased locking member784that is adapted to retainingly engage the locking grooves757,759when the drive shaft assembly is in the first and second axial positions, respectively. The locking members784have a tapered tip786and are movably supported within the differential housing762. A radial wave spring782may be employed to apply a biasing force to the locking members784as shown inFIG.63. When the drive shaft assembly is axially moved into the first position, the locking members784snap into engagement with the first radial locking groove7576. SeeFIG.65. When the drive shaft assembly is axially moved into the second axial position, the locking members784snap into engagement with the second radial locking groove759. SeeFIG.64. In alternative embodiments, the first and second retention formations may comprise, for example, dimples that correspond to each of the locking members784. Also in alternative embodiments wherein the drive shaft assembly is axially positionable in more than two axial positions, addition retention formations may be employed which correspond to each of those axial positions. FIGS.70and71illustrate an alternative differential locking system790that is configured to ensure that the drive shaft assembly is locked into one of a plurality of predetermined axial positions. The differential locking system790is configured to ensure that the drive shaft assembly is positionable in one of the first and second axial positions and is not inadvertently positioned in another axial position wherein the drive system is not properly operable. In the embodiment depicted inFIGS.70and71, the differential locking system790includes a plurality of locking springs792that are attached to the drive shaft assembly. Each locking spring792is formed with first and second locking valleys794,796that are separated by a pointed peak portion798. The locking springs792are located to cooperate with a pointed locking members763formed on the differential housing762. Thus, when the pointed locking members763are seated in the first locking valley794, the drive shaft assembly is retained in the first axial position and when the pointed locking members763are seated in the second locking valleys796, the drive shaft assembly is retained in the second axial position. The pointed peak portion798between the first and second locking valleys794,796ensure that the drive shaft assembly is in one of the first and second axial positions and does not get stopped in an axial position between those two axial positions. If additional axial positions are desired, the locking springs may be provided with additional locking valleys that correspond to the desired axial positions. Referring toFIGS.60,72and73, a thrust bearing1030is supported within a cradle1026in the elongate channel1020. The distal end portion1306of the implement drive shaft1300is rotatably received within the thrust bearing1030and protrudes therethrough. A retaining collar1032is pinned or otherwise affixed to the distal end1030as shown inFIG.73to complete the installation. Use of the thrust bearing1030in this manner may enable the firing member1200to be “pulled” as it is fired from a starting position to an ending position within the elongate channel1020. Such arrangement may minimize the risk of buckling of the implement drive shaft1300under high load conditions. The unique and novel mounting arrangement and location of the thrust bearing1030may result in a seating load that increases with the anvil load which further increases the end effector stability. Such mounting arrangement may essentially serve to place the implement drive shaft1300in tension during the high load firing cycle. This may avoid the need for the drive system gears to both rotate the implement drive shaft1300and resist the buckling of the shaft1300. Use of the retaining collar1032may also make the arrangement easy to manufacture and assemble. The firing member1200is configured to engage the anvil and retain the anvil at a desired distance from the cartridge deck as the firing member1200is driven from the starting to ending position. In this arrangement for example, as the firing member1200assembly moves distally down the elongate channel1020, the length of the portion of the anvil that resembles a cantilever beam becomes shorter and stiffer thereby increasing the magnitude of downward loading occurring at the distal end of the elongate channel1020further increasing the bearing seating load. One of the advantages of utilizing rotary drive members for firing, closing, rotating, etc. may include the ability to use the high mechanical advantage of the drive shaft to accommodate the high loads needed to accomplish those instrument tasks. However, when employing such rotary drive systems, it may be desirable to track the number of rotations that the drive shaft is driven to avoid catastrophic failure or damage to the drive screw and other instrument components in the event that the drive shaft or movable end effector component is driven too far in the distal direction. Thus, some systems that include rotary drive shafts have, in the past, employed encoders to track the motor rotations or sensors to monitor the axial position of the movable component. The use of encoders and/or sensors require the need for additional wiring, electronics and processing power to accommodate such a system which can lead to increased instrument costs. Also, the system's reliability may be somewhat difficult to predict and its reliability depends upon software and processors. FIGS.74-76depict a mechanical stroke limiting system1310for limiting the linear stroke of the firing member1200as the firing member1200is driven from a starting to an ending position. The stroke limiting system1310employs an implement drive shaft1300′ wherein the screw threads1308on the implement drive shaft1300′ do not extend to the distal end1306of the drive shaft1300′. For example, as can be seen inFIGS.74-76, the implement drive shaft1300′ includes an un-threaded section1309. The firing member1200has a body portion1202that has a series of internal threads1204that are adapted to threadably interface with the screw threads1308on the implement drive shaft1300′ such that, as the implement drive shaft1300′ is rotated in a first firing direction, the firing member1200is driven in the distal direction “DD” until it contacts the unthreaded section1309at which point the firing member1200stops its distal advancement. That is, the firing member1200will advance distally until the internal threads1204in the firing member1200disengage the threads1308in the implement drive shaft1300′. Any further rotation of the implement drive shaft1300′ in the first direction will not result in further distal advancement of the firing member1200. See, e.g.,FIG.75. The illustrated exemplary mechanical stroke limiting system1310further includes a distal biasing member1312that is configured to be contacted by the firing member1200when the firing member1200has been advanced to the end of its distal stroke (i.e., the firing member will no longer advance distally with the rotation of the implement drive shaft in the first rotary direction). In the embodiment depicted inFIGS.74-76, for example, the biasing member1312comprises a leaf spring1314that is positioned within the elongate channel1020as shown.FIG.74illustrates the leaf spring1314prior to contact by the firing member1200andFIG.75illustrates the leaf spring1314in a compressed state after it has been contacted by the firing member1200. When in that position, the leaf spring1314serves to bias the firing member1200in the proximal direction “PD” to enable the internal threads1204in the firing member1200to re-engage the implement drive shaft1300′ when the implement drive shaft1300′ is rotated in a second retraction direction. As the implement drive shaft1300′ is rotated in the second retraction direction, the firing member1200is retracted in the proximal direction. SeeFIG.76. FIGS.77-80illustrate another stroke limiting system1310′. The stroke limiting system1310′ employs a two-part implement drive shaft1300″. In at least one form, for example, the implement drive shaft1300″ includes a proximal implement drive shaft segment1320that has a socket1324in a distal end1322thereof and a distal drive shaft segment1330that has a lug1334protruding from a proximal end1332thereof. The lug1334is sized and shaped to be received within the socket1324such that threads1326on the proximal drive shaft segment1320cooperate with threads1336on the distal drive shaft segment1330to form one continuous drive thread1340. As can be seen inFIGS.77,79and80, a distal end1338of the distal drive shaft segment1330extends through a thrust bearing1032that is movably supported in the distal end1023of the elongate channel1020. That is, the thrust bearing1032is axially movable within the elongate channel1020. A distal biasing member1342is supported within the elongate channel1020for contact with the thrust bearing1032.FIG.78illustrates the firing member1200being driven in the distal direction “DD” as the implement drive shaft1300″ is driven in a first rotary direction.FIG.79illustrates the firing member1200at the distal end of its stroke. Further rotation of the implement drive shaft1300″ in the first rotary direction causes the thrust bearing1032to compress the biasing member1342and also allows the distal shaft segment1330to slip if the proximal segment1320continues to turn. Such slippage between the proximal and distal implement drive shaft segments1320,1330prevent the firing member1200from being further advanced distally which could ultimately damage the instrument. However, after the first rotary motion has been discontinued, the biasing member1342serves to bias the distal shaft segment1320in the proximal direction such that the lug1334is seated in the socket1324. Thereafter, rotation of the implement shaft1300″ in a second rotary direction results in the movement of the firing member1200in the proximal direction “PD” as shown inFIG.80. FIG.81illustrates another stroke limiting system1310″. In this embodiment, the implement drive shaft1300has a lug1350formed thereon that is sized and shaped to be received within a socket1352in the bearing segment1304that has the implement drive gear1302formed thereon or otherwise attached thereto.FIGS.81A and81Billustrate different lugs1350′ (FIG.81A) and1350″ (FIG.81B) that are configured to releasably engage corresponding sockets1352′ and1352″, respectively. The leaf spring1314is positioned to be contacted by the firing member1200when the firing member1200has reached the end of its stroke. Further rotation of the implement drive shaft1300will result in the lug1350,1350′,1350″ slipping out of the socket1352,1352′,1352″, respectively to thereby prevent further rotation of the implement shaft1300. Once the application of rotational motion to the implement drive shaft1300is discontinued, the leaf spring1314will apply a biasing motion to the firing member1200to ultimately bias the implement drive shaft1300in the proximal direction “PD” to seat the lug1350in the socket1352. Rotation of the implement drive shaft1300in the second rotary direction will result in the retraction of the firing member1200in the proximal direction “PD” to the starting position. Once the firing member1200has returned to the starting position, the anvil1100may then be opened. In the illustrated exemplary embodiment, the firing member1200is configured to engage the anvil1100as the firing member1200is driven distally through the end effector to affirmatively space the anvil from the staple cartridge to assure properly formed closed staples, especially when an amount of tissue is clamped that is inadequate to do so. Other forms of firing members that are configured to engage and space the anvil from the staple cartridge or elongate channel and which may be employed in this embodiment and others are disclosed in U.S. Pat. No. 6,978,921, entitled SURGICAL STAPLING INSTRUMENT INCORPORATING AN E-BEAM FIRING MECHANISM, the disclosure of which is herein incorporated by reference in its entirety. As can be seen inFIGS.82and83, the body portion1202of the firing member1200includes a foot portion1206that upwardly engages a channel slot1028in the elongate channel1020. SeeFIG.60. Similarly, the knife body includes a pair of laterally-protruding upper fins1208. When fired with the anvil1100closed, the upper fins1208advance distally within a longitudinal anvil slot1103extending distally through anvil1100. Any minor upward deflection in the anvil1100is overcome by a downward force imparted by the upper fins1208. In general, the loads necessary to close and advance the firing member i.e., “fire” the firing member could conceivably exceed 200 lbs. Such force requirements, however, may require the internal threads1204in the firing member to comprise relative fine threads of a power-type thread configuration such as Acme threads. Further, to provide sufficient support to the upper fins1208to avoid the firing member1200from binding as it is driven distally through the end effector, it may be desirable for at least 5-15 threads in the firing member to be engaged with the threads on the implement drive shaft at any given time. However, conventional manufacturing methods may be unsuitable for forming sufficient threads in the firing member body1202within an 0.08 inch-0.150 inch diameter opening and which have sufficient thread depth. FIGS.82-84illustrate a firing member1200′ that may address at least some of the aforementioned challenges. As can be seen in those Figures, the body portion1202′ of the firing member has a hollow shaft socket1210extending therethrough that is sized to receive the implement shaft therethrough. The internal threads in this embodiment are formed by a series of rods1214that extend transversely through holes1212in the shaft socket1210as shown. As can be seen inFIG.84, the pins1214rest on the minor diameter of the pitch of the threads1308on the implement drive shaft1300. FIG.85illustrates another firing member1200″ that may also address at least some of the above-discussed manufacturing challenges. As can be seen in that Figure, the body portion1202″ of the firing member100″ has a hollow shaft socket1210extending therethrough that is sized to receive the implement shaft therethrough. A pair of windows1216are formed in the body portion1202″ as shown. The internal threads1220in this embodiment are formed on plugs1218that are inserted into the windows1216and are attached therein by welding, adhesive, etc.FIGS.86and87illustrate another firing member1200″ wherein access into the socket1210is gained through access windows1230A,1230B formed in the body portion1202″. For example, a pair of access windows1230A are provided through one side of the socket portion1210to enable internal thread segments1232to be formed within the opposite wall of the socket1210. Another access window1230B is provided through the opposite side of the socket portion1210so that a central internal thread segment1234can be formed in the opposite wall between the internal thread segments1232. The thread segments1232,1234cooperate to threadably engage the threads1308on the implement drive shaft1300. End effector1000is configured to removably support a staple cartridge1040therein. SeeFIG.60. The staple cartridge1040includes a cartridge body1042that is configured to be operably seated with the elongate channel1020. The cartridge body1042has an elongate slot1046therein for accommodating the firing member1200. The cartridge body1042further defines an upper surface referred to herein as the cartridge deck1044. In addition, two lines of staggered staple apertures1048are provided on each side of the elongate slot1046. The staple apertures1048operably support corresponding staple drivers1050that support one or two surgical staples (not shown) thereon. A variety of such staple driver arrangements are known and may be employed without departing from the spirit and scope of the various exemplary embodiments of the invention. The firing member embodiments also employ a wedge sled assembly1250for driving contact with the staple drivers operably supported within the staple cartridge1040. As can be seen inFIG.60, the wedge sled assembly1250includes at least two wedges1252that are oriented for driving contact with the lines of staple drivers operably supported within the staple cartridge1040. As the firing member1200is driven distally, the wedge sled assembly1250travels with the firing member1220and the wedges1252thereon force the drivers1050upward towards the closed anvil1100. As the drivers1050are driven upwardly, the surgical staples supported thereon are driven out of their respective apertures1048into forming contact with the staple forming surface1104of the closed anvil1100. Various exemplary end effector embodiments disclosed herein may also employ a unique and novel firing lockout arrangement that will prevent the clinician from inadvertently advancing or “firing” the firing member when a cartridge is not present, a cartridge has not been properly seated within the end effector and/or when a spent cartridge remains installed in the end effector. For example, as will be discussed in further detail below, the firing lockout arrangement may interact with the implement drive shaft1300and/or the firing member1200to prevent inadvertent advancement of the firing member1200when one of the aforementioned conditions exist. In the illustrated exemplary embodiment, rotation of the implement drive shaft1300in a first rotary or “firing” direction will cause the firing member1200to be driven distally through the staple cartridge1040if the firing member1200is properly aligned with the elongate slot1046in the cartridge body1042(FIG.60), the channel slot1028in the elongate channel1020and the anvil slot1103in the anvil1100, for example. Referring primarily toFIG.90, the elongate slot1046, the channel slot1028and/or the anvil slot1103can guide the firing member1200as it moves along the path through the surgical end effector1000, for example, during a firing stroke. When the firing member1200is in the operable configuration, the channel slot1028is configured to receive the foot portion1206of the firing member1200and the anvil slot1103is configured to receive the upper fins1208of the firing member1200, for example. When a portion of the firing member1200is positioned in the channel slot1028and/or the anvil slot1103, the firing member1200can be aligned or substantially aligned with the axis A. The channel slot1028and/or the anvil slot1103can guide the firing member1200and maintain the alignment of the firing member1200with the axis A as the firing member1200moves from the initial position to the secondary position relative to the cartridge body1042, for example. As was briefly discussed above, in various surgical staple cartridge examples, the surgical staples are supported on movable staple drivers supported in the cartridge body. Various exemplary end effector embodiments employ a wedge sled assembly1250that is configured to contact the staple drivers as the wedge sled assembly is driven distally through the staple cartridge to drive the staples out of their respective cavities in the cartridge body and into forming contact with the closed anvil. In at least one exemplary embodiment, the wedge sled1250is positioned within the staple cartridge1040. Thus, each new staple cartridge1040has its own wedge sled operably supported therein. When the clinician properly seats a new staple cartridge1040into the elongate channel, the wedge sled1250is configured to straddle the implement drive shaft1300and engage the firing member1200in the manner illustrated inFIGS.60,88and89, for example. As can be seen in those Figures, the exemplary wedge sled assembly1250can comprise a sled body1414, a flange1410, and wedges1252. The sled body1414can be positioned around a portion of the implement drive shaft1300when the wedge sled assembly1250is positioned in the elongate channel1020. The sled body1414can be structured such that the sled body1414avoids contact with the implement drive shaft1300when the sled body1414is positioned around the implement drive shaft1300. The sled body1414can comprise a contour1412, for example, that curves over and/or around the implement drive shaft1300. In such embodiment, for example, a flange1410extends between the sled body1414and each of the wedges1252. In addition, the sled body1414has a notch1415therein that is configured to receive therein a portion of the firing member body1203. Referring primarily toFIG.89, the flange1410can extend substantially parallel to the foot portion1206of the firing member1200when the firing member1200engages the wedge sled assembly1250. When a new staple cartridge1040has been properly installed in the elongate channel1020, initial actuation of the firing member1200(e.g., by rotating the implement drive shaft1300) causes a portion of the firing member body1203to enter the notch1415in the wedge sled1250which thereby results in the alignment of the firing member1200with the elongate slot1046in the cartridge body1042(FIG.60), the channel slot1028in the elongate channel1020and the anvil slot1103in the anvil1100to enable the firing member1200to be distally advanced through the staple cartridge1040. Hence, the wedge sled may also be referred to herein as an “alignment member”. If the staple cartridge1040has been improperly installed in the elongate channel, activation of the firing member1200will not result in the aligning engagement with the notch1415in the wedge sled1250and the firing member1200will remain out of alignment with the channel slot1028in the elongate channel1020and the anvil slot1103in the anvil1100to thereby prevent the firing member1200from being fired. After a new staple cartridge1040has been properly installed in the elongate channel1020, the clinician fires the firing member by applying a first rotary motion to the implement drive shaft1300. Once the firing member1200has been distally driven through the staple cartridge1040to its distal-most position, a reverse rotary motion is applied to the implement drive shaft1300to return the firing member1200to its starting position external to the surgical staple cartridge1040to enable the spent cartridge to be removed from the elongate channel1020and a new staple cartridge to be installed therein. As the firing member1200is returned to its starting position, the wedge sled1250remains in the distal end of the staple cartridge and does not return with the firing member1200. Thus, as the firing member1200moves proximally out of the staple cartridge1040and the anvil slot1103in the anvil, the rotary motion of the implement drive shaft1300causes the firing member1200to pivot slightly into an inoperable position. That is, when the firing member1200is in the inoperable position (outside of the cartridge), should the clinician remove the spent cartridge1040and fail to replace it with a fresh cartridge containing a new wedge sled1250and then close the anvil1110and attempt to fire the firing member1200, because there is no wedge sled present to align the firing member1200, the firing member1200will be unable to advance distally through the elongate channel1020. Thus, such arrangement prevents the clinician from inadvertently firing the firing member1200when no cartridge is present. In such exemplary embodiment, the firing member1200can be substantially aligned with an axis A when the firing member1200is oriented in an operable configuration such that the firing member1200can move along a path established through the end effector1000. The axis A can be substantially perpendicular to the staple forming surface1104of the anvil1100and/or the cartridge deck1044of the staple cartridge1040(FIG.60). In other exemplary embodiments, the axis A can be angularly oriented relative to the staple forming surface1104of the anvil1100and/or the cartridge deck1044of the staple cartridge1040. Further, in at least one exemplary embodiment, the axis A can extend through the center of the surgical end effector1000and, in other exemplary embodiments, the axis A can be positioned on either side of the center of the surgical end effector1000. FIGS.91-97illustrate one exemplary form of a surgical end effector1400that employs a unique and novel firing lockout arrangement. As can be seen inFIGS.91-95, when the firing member1200is in the initial position, the firing member1200is in an inoperable configuration which prevents its distal advancement through the end effector due to the misalignment of the firing member1200with the channel slot1028and the anvil slot1103. The firing member1200may be retained in the inoperable configuration by a firing lockout generally designated as1418. Referring primarily toFIGS.91-93, in at least one form, for example, the firing lockout1418includes a first lockout groove or notch1402that is formed in the elongate channel1020. In other exemplary embodiments, however, the first lockout notch1402can form an opening in the first jaw1004, the second jaw1006, the elongate channel1020and/or the anvil1100, for example. In various exemplary embodiments, the first lockout notch1402is located in the surgical end effector1400such that the first lockout notch1402retainingly engages a portion of the firing member1200when the firing member1200is in the inoperable configuration. The first lockout notch1402can be near, adjacent to, and/or connected to the channel slot1028in the elongate channel1020, for example. Referring primarily toFIG.91, the channel slot1028can have a slot width along the length thereof. In at least one exemplary embodiment, the first lockout notch1402can extend from the channel slot1028such that the combined width of the channel slot1028and the first lockout notch1402exceeds the slot width of the channel slot1028. As can be seen inFIG.91, when the firing member1200is in the inoperable configuration, the foot portion1206of the firing member1200extends into the first lockout notch1402to thereby prevent its inadvertent distal advancement through the elongate channel1020. When a new staple cartridge1040has been properly installed in the elongate channel1020, initiation of the firing stroke causes the firing member to engage the wedge sled1250positioned within the staple cartridge1040which moves the firing member1200into driving alignment with the elongate slot1046in the cartridge body1042, the channel slot1028in the elongate channel1020and the anvil slot1103in the anvil1100to enable the firing member1200to be distally advanced therethrough. As the firing member1200moves from the initial position to the secondary position relative to the staple cartridge1040, the firing member1200can move past the first lockout notch1402, for example. The first lockout notch1402can have a length of approximately 0.25 inches, for example. In some other exemplary embodiments, the first lockout notch1402can have a length of approximately 0.15 inches to approximately 0.25 inches, for example, or of approximately 0.25 inches to approximately 1.0 inch, for example. Referring primarily toFIGS.93and94, the surgical end effector1400can be structured to accommodate the upper fins1208of the firing member1200when the firing member1200is in the inoperable configuration. For example, the firing lockout1418can include a second lockout groove or notch1404in the anvil1100. In the illustrated exemplary embodiment, for example, the second lockout notch1404can be near, adjacent to, and/or connected to the anvil slot1103in the anvil1100, for example. The anvil slot1103can have a slot width along the length thereof. In at least one exemplary embodiment, the second lockout notch1404can extend from the anvil slot1103such that the combined width of the anvil slot1103and the second lockout notch1404exceeds the slot width of the anvil slot1103. The second lockout notch1404can extend a length or distance in the surgical end effector1400. The firing member1200can be structured to engage the second lockout notch1404along the length thereof when the firing member1200is in the inoperable configuration. As the firing member1200moves from the initial position to the secondary position relative to the staple cartridge1040, the firing member1200can move past the second lockout notch1404, for example. The second lockout notch1404can have a length of approximately 0.25 inches, for example. In some other exemplary embodiments, the second lockout notch1404can have a length of approximately 0.15 inches to approximately 0.25 inches, for example, or of approximately 0.25 inches to approximately 1.0 inch, for example. Referring primarily toFIG.93, the first lockout notch1402can extend from the channel slot1028in a first direction X and the second lockout notch1404can extend from the anvil slot1103in a second direction Y. In at least one exemplary embodiment, the first direction X can be substantially laterally opposite to the second direction Y. In such exemplary embodiments, the foot portion1206of the firing member1200can pivot into the first lockout notch1402and the upper fins1208of the firing member1200can pivot into the second lockout notch1404when the firing member1200moves to the inoperable configuration. Referring primarily toFIGS.92-94, when the firing member1200is oriented in the inoperable configuration, corresponding portions of the firing member1200engage the first and second lockout notches1402,1404. The firing member1200can be positioned at least partially within the first and second lockout notches1402,1404when the firing member1200is in the inoperable configuration. The firing member1200can shift into the first and second lockout notches1402,1404when the firing member1200moves to the inoperable configuration. Further, when the firing member1200is oriented in the operable configuration, the firing member1200can disengage the first and second lockout notches1402,1404. A portion or portions of the surgical end effector1400can block the firing member1200and limit or prevent movement of the firing member1200through the surgical end effector1400when the firing member1200is oriented in the inoperable configuration (see, e.g., FIG.95). For example, the first jaw1004, the second jaw1006, the elongate channel1020and/or the anvil1100can be configured to block the firing member1200when it is in the operable configuration. In some exemplary embodiments, the first lockout notch1402has a first blocking surface or edge1406(FIGS.91and92) formed thereon and the second lockout notch1404has a second blocking surface or edge1408formed thereon (FIG.94). Attempts to fire the firing member1200while the firing member1200is in the inoperable configuration will result in corresponding portions of the firing member1200contacting one or both of the first and second blocking surfaces1406,1408to prevent the firing member1200from moving from the initial position towards the secondary positions. In at least one exemplary embodiment, the surgical end effector1400need not have both the first blocking edge1406and the second blocking edge1408. FIGS.97-104illustrate another exemplary surgical end effector embodiment1500that employs another exemplary firing lockout arrangement. For example, as can be seen in those Figures, a surgical end effector1500can comprise the elongate channel1020, the implement drive shaft1300, and the firing member1200. The surgical end effector1500can also comprise an end effector drive housing1510(see, e.g.FIG.100). Similar to the end effector drive housing1010described herein, the end effector drive housing1510can comprise a bearing sleeve1511and the third ring gear or housing drive member768. The bearing sleeve1511can be structured such that the bearing segment1304of the implement drive shaft1300can be moveably positioned in the bearing sleeve1511. The bearing segment1304can move in the bearing sleeve1511as the implement drive shaft1300moves between an inoperable position and an operable position, as described herein. The bearing sleeve1511can comprise a bore1512having an elongated cross-section such as, for example, a cross-sectional shape comprising an oval, an ellipse and/or semicircles having longitudinal and/or parallel sides therebetween. In such exemplary embodiments, the bearing segment1304can be positioned against or near a first side of the bore1512such as, for example, a first semicircle, when the implement drive shaft1300is in the inoperable position. Further, the bearing segment1304can be positioned against or near a second side of the bore1512such as, for example, a second semicircle, when the implement drive shaft1300is in the operable position. The implement drive shaft1300can be moveable between the inoperable position and the operable position. As described herein, a biasing member1520and/or a portion of the staple cartridge1040can move the implement drive shaft1300between the inoperable position and the operable position, for example. In the illustrated embodiment and others, the implement drive gear1302of the implement drive shaft1300can be engaged with the third ring gear768of the end effector drive housing1510when the implement drive shaft1300is in the operable position. The implement drive gear1302can be an external gear, for example, and the third ring gear768can be an internal gear, for example. The implement drive gear1302can move into engagement with the third ring gear768when the implement drive shaft1300moves from the inoperable position to the operable position. Further, the implement drive gear1302can be disengaged from the third ring gear768when the implement drive shaft1300is in the inoperable position. In at least one exemplary embodiment, the implement drive gear1302can move out of engagement with the third ring gear768when the implement drive shaft1300moves from the operable position to the inoperable position. Similar to other exemplary embodiments described herein, when the implement drive shaft1300is engaged with the third ring gear768in the end effector drive housing1510, the drive system750(FIG.61) can drive the firing member1200through the elongate channel1020of the surgical end effector1500, for example, during a firing stroke. Referring primarily toFIGS.101and102, the bearing segment1304can be positioned against the first side of the bore1512of the bearing sleeve1511when the implement drive shaft1300is in the inoperable position. A retaining pin1514(FIGS.98,100,101and103) can be structured to bias the bearing segment1304against the first side of the bore1512such that the implement drive shaft1300is held in the inoperable position, for example, and the implement drive gear1302is held out of engagement with the third ring gear768, for example. In some exemplary embodiments, the retaining pin1514can be spring-loaded such that retaining pin1514exerts a force on the bearing segment1304to move the implement drive shaft1300towards the inoperable position. The implement drive shaft1300can remain in the inoperable position until another force overcomes the force exerted by the retaining pin1514to move the implement drive shaft1300towards the operable position, for example, and the implement drive gear1302into engagement with the third ring gear768, for example. Referring primarily toFIGS.103and104, the bearing segment1304can be positioned against the second side of the bore1512of the bearing sleeve1511when the implement drive shaft1300is in the operable position. In various exemplary embodiments, the force exerted by the retaining pin1514(FIGS.98,100,101and103) can be overcome to move the bearing segment1304against the second side of the bore1512such that the implement drive shaft1300is in the operable position, for example, and the implement drive gear1302is engaged with the third ring gear768, for example. As described herein, the biasing element1520can exert a force on the bearing segment1304that overcomes the force exerted by the retaining pin1515, for example. The surgical end effector1500can comprise the biasing element1520, which can be moveable between a first set of positions (see, e.g.,FIG.103) and a second set of positions (see, e.g.,FIG.101). The second set of positions can be distal to the first set of positions relative to the end effector drive housing1510. When the biasing element1520is in the first set of positions, the biasing element1520can be structured to move the implement drive shaft1300to the operable position, for example. When the biasing element1520is in the second set of positions, the biasing element1520can release the implement drive shaft1300such that the implement drive shaft can return to the inoperable position, for example. The biasing element1520can be an independent element positionable in the surgical end effector1500. The biasing element1520can be moveably retained in the surgical end effector1500, for example, and can be operably engageable with the staple cartridge1040, for example. The staple cartridge1040can comprise the biasing element1520. In some exemplary embodiments, the biasing element1520can be integrally formed with the wedge sled assembly1250of the staple cartridge1040, for example, and the biasing element1520can be moveably retained in the staple cartridge1040, for example. In such exemplary embodiments, the biasing element1520can move through the elongate channel1020as the wedge sled assembly1250and/or the firing member1200moves through the elongate channel1020, for example, during a firing stroke. Referring primarily toFIG.99, the biasing element1520can comprise a biasing body1522and legs1526extending from the biasing body1522. The biasing body1522can be positioned around a portion of the implement drive shaft1300in the surgical end effector1500. In some exemplary embodiments, the biasing body1522can be structured such that the biasing body1522avoids contact with the implement drive shaft1300when the biasing body1522is positioned around the implement drive shaft1300. The biasing body1522can comprise a contour1524, for example, that curves over and/or around the implement drive shaft1300. The legs1526can extend along a portion of the elongate channel1020and/or on either side of the implement drive shaft1300. The biasing element1520can also comprise at least one extension or wedge1528. As described herein, the wedge1528can moveably engage the bearing sleeve1511and/or the bearing segment1304to move the implement drive shaft into the operable position. The biasing element1520can also comprise at least one spring1530. The spring1530can be deformable between an initial configuration (FIG.101) and deformed configurations (FIG.103), for example. The spring1530can hold the biasing element1520in the first set of positions relative to the end effector drive housing1510until a force deforms the spring1530from the initial configuration to a deformed configuration. When the spring1530moves from the initial configuration to the deformed configuration, the biasing element1520can move from the second set of positions to the first set of positions relative to the end effector drive housing1510. Referring primarily toFIG.101, before the insertion of the staple cartridge1040(FIG.103) into the elongate channel1020, the spring1530can be in the initial configuration, for example, and the biasing element1520can be in the second set of positions, for example. The retaining pin1514can hold the bearing segment1304against the first side of the bore1512, for example. In such exemplary embodiments, the implement drive shaft1300can be held in the inoperable position by the retaining pin1514. Referring now toFIG.103, installation of the staple cartridge1040in the elongate channel1020moves the biasing element1520proximally against the force of springs1530into a first set of positions wherein the wedge1528moveably engages the bearing sleeve1511and the bearing segment1304to bias the bearing segment1304and the implement drive gear1302of the implement drive shaft1300into meshing engagement with the third ring gear768. Thereafter, actuation of the firing drive system as described herein will result in the firing of the firing member1200. In some exemplary embodiments, a portion of the staple cartridge1040is configured to directly contact the biasing element1520to move the biasing element1520to the first set of positions. In other exemplary embodiments, a portion of the staple cartridge1040is configured to contact another element in the surgical end effector1500such as, for example, the firing member1200, to operable move the biasing element1520to the first set of positions. In still other exemplary embodiments, the staple cartridge1040has the biasing element1520integrally formed therewith. In various exemplary embodiments, the biasing element1520can move through the elongate channel1020of the surgical end effector1500as the firing member1200and/or the wedge sled assembly1250are driven through the elongate channel1020by the implement drive shaft1300, for example, during a firing stroke, as described herein. The biasing element1520can be integrally formed with and/or fixed to the wedge sled assembly1250of the staple cartridge1040. In such exemplary embodiments, when the staple cartridge1040is initially seated in the elongate channel1020, the wedge sled assembly1250and the biasing element1520can be positioned in an initial position relative to the staple cartridge1040and/or the elongate channel1020. The initial position of the biasing element1520can correspond to the first set of positions such that the biasing element1520moveably engages the bearing sleeve1511of the end effector drive housing1510to move the implement drive shaft1300into the operable position, as described herein. During the firing stroke, the wedge sled assembly1250and the biasing element1520can be moved away from the initial or first set of positions, for example. The biasing element1520can move to the second set of positions, for example. When the biasing element1520moves past the first set of positions and into the second set of positions, the biasing element1520may no longer engage the bearing sleeve1511of the end effector drive housing1510to hold the implement drive shaft1300in the operable configuration. Though the biasing element1520may not bias the implement drive gear1302of the implement drive shaft1300into engagement with the third ring gear768when the biasing element1520moves into the second set of positions, the channel slot1028, the anvil slot1103, and/or the elongate slot1046in the staple cartridge1040serve to guide the firing member1200in a firing orientation that retains the implement drive gear1302of the implement drive shaft1300in meshing engagement with the third ring gear768and thereby prevents the implement drive shaft1300from returning to the inoperable position during the firing stroke. In at least one exemplary embodiment, the firing member1200and/or the implement drive shaft1300can drive the wedge sled assembly1250and/or the biasing element1520to the second set of positions during the firing stroke. In various exemplary embodiments, upon completion of the firing stroke, the firing member1200can return to the initial position, however, the wedge sled assembly1250, including the biasing element1520, can remain in the second set of positions, for example. The firing member1200can return to a proximal position in the surgical end effector1500, for example, and the biasing element1520can remain in a distal position in the surgical end effector1500, for example. When the firing member1200is in the initial position and the biasing element1520is in the second set of positions, the bearing segment1304of the implement drive shaft1300can shift in the bearing sleeve1511such that the implement drive shaft1300moves into the inoperable position, for example, and the implement drive gear1302moves out of engagement with the third ring gear768, for example. In various exemplary embodiments, the implement drive shaft1300can remain in the inoperable position until the biasing element1520is drawn back into the first set of positions and/or until a replacement biasing element1520is positioned in the first set of positions, for example. For example, the spent staple cartridge1040is removed from the elongate channel1020and replaced with a replacement staple cartridge1040, which can comprise a biasing element1520located in its first positions. When the replacement staple cartridge1040is positioned in the elongate channel1020, the biasing element1520thereof shifts the implement drive gear1302into engagement with the third ring gear768, for example, and into the operable position, for example. In such exemplary embodiments, the surgical end effector1500can be prevented from being re-fired when no cartridge1040or a spent cartridge1040is seated in the elongate channel1020. In addition, if the staple cartridge has not been properly seated in the elongate channel1020such that the biasing element1520has not moved the implement drive shaft1300into meshing engagement with the third ring gear768, the firing member1200cannot be fired. As described above, a surgical instrument system can include a surgical housing, replaceable end effector assemblies that can be connected to the surgical housing for use during a surgical technique and then disconnected from the housing after they have been used, and a motor and/or an actuator configured to fire the end effectors. In various circumstances, a surgeon can choose from several different replaceable end effectors for use during a surgical procedure. For example, a surgeon may first select a first replaceable end effector configured to staple and/or incise a patient's tissue that includes a staple cartridge length of approximately 15 millimeters (“mm”), for example, to make a first cut in the patient tissue. In such an embodiment, a cutting blade and/or a staple-driving sled can be advanced along the approximately 15 mm length of the staple cartridge by a drive screw in order to cut and staple approximately 15 mm of patient tissue. The surgeon may then select a second replaceable end effector, also configured to staple and/or incise patient tissue, which can include a staple cartridge length of approximately 30 mm to make a second cut in the patient's tissue. In such an embodiment, a cutting blade and/or a staple-driving sled can be advanced along the approximately 30 mm length of the staple cartridge by a drive screw to cut and staple approximately 30 mm of the patient's tissue. The surgeon may also select a replaceable end effector configured to staple and/or incise patient tissue that includes a staple cartridge length of approximately 45 mm to make a cut in the patient's tissue, for example. In such an embodiment, a cutting blade and/or a staple driving sled can be advanced along the approximately 45 mm length of the staple cartridge by a drive screw to cut and staple approximately 45 mm of the patient's tissue. The surgeon may also select a replaceable end effector, which can also be configured to staple and/or incise patient tissue, which includes a staple cartridge length of approximately 60 mm to make a cut in the patient's tissue, for example. In such an embodiment, a cutting blade and/or a staple driving sled can be advanced along the approximately 60 mm length of the staple cartridge by a drive screw to cut and staple approximately 60 mm of the patient's tissue. The 15 mm, 30 mm, 45 mm, and/or 60 mm lengths of the end effectors discussed above are exemplary. Other lengths can be used. In certain embodiments, a first end effector can include a staple cartridge having a length of x, a second end effector can include a staple cartridge having a length of approximately 2*x, a third end effector can include a staple cartridge having a length of approximately 3*x, and a fourth end effector can include a staple cartridge having a length of approximately 4*x, for example. In some surgical instrument systems utilizing replaceable end effectors having different lengths, the drive screws in each of the different replaceable end effectors may be identical except that the length of each drive screw may be different in order to accommodate the different length of the associated replaceable end effector. For example, a replaceable end effector comprising a 30 mm staple cartridge may require a drive screw which is longer than the drive screw of a replaceable end effector comprising a 15 mm staple cartridge. In each instance of such surgical instrument systems, however, each drive screw which utilizes the same thread pitch and/or thread lead, described in greater detail below, may require the motor to rotate the drive shaft a different number or revolutions depending on the length of the end effector being used in order for each end effector to be fully fired. For instance, a drive screw providing a 30 mm firing stroke may require twice as many revolutions in order to be fully actuated as compared to a drive screw providing a 15 mm firing stroke. In such surgical instrument systems, electronic communication between the surgical housing and the replaceable end effector can be utilized to ensure that the electric motor in the surgical housing turns a correct number of revolutions for the length of the attached replaceable end effector. For example, a replaceable end effector may include an electronic circuit that can be identified by the surgical instrument system so that surgical instrument system can turn the motor a correct number of revolutions for the attached end effector. In addition to or in lieu of the above, the replaceable end effector may include a sensor that senses when an end effector has been completely actuated. In such an embodiment, the sensor can be in signal communication with a controller in the housing configured to stop the motor when the appropriate signal is received. While suitable for their intended purposes, such electronic communication between the surgical housing and the replaceable end effector may increase the complexity and/or cost of such surgical instrument systems. As outlined above, end effectors having different lengths can be used on the same surgical instrument system. In the surgical instrument systems described above, replaceable end effectors having different firing lengths include drive screws that revolve a different number of times to accommodate the different firing lengths. In order to accommodate the different number of revolutions required for different drive screws, the motor driving the drive screw is operated for a longer duration or a shorter duration, and/or a larger number of revolutions or a smaller number of revolutions, depending on whether a longer firing length or a shorter firing length is needed. Embodiments of replaceable end effectors described below enable a surgical instrument system comprising a motor configured to turn a fixed or set number of revolutions to actuate end effectors having different firing lengths. By operating the motor a fixed number of revolutions, the need for the surgical instrument system to identify the length of the end effector may not be necessary. Each end effector in the embodiments described below includes a drive screw with a thread pitch and/or thread lead that enables an actuating portion of an end effector, such as a cutting blade, for example, to travel the full length of a particular end effector in the fixed number of revolutions of the motor. Referring toFIG.105, a drive screw1700can be rotated in a first direction to move a cutting blade1730of an end effector1740in a distal direction indicated by arrow E. In use, the drive screw1700can be rotated a fixed or set number of times to advance the cutting blade1730a full firing length, indicated by length L inFIG.105. For each revolution of the drive screw1700, in certain embodiments, the cutting blade1730can be moved in the direction of arrow E by an amount equal to the thread pitch, thread lead, and/or distance between adjacent windings of thread1708on the drive screw1700, described below in greater detail. In various embodiments, a first drive screw can include a first set of characteristics that defines a first firing length while a second drive screw can include a second set of characteristics that defines a second firing length wherein the first set of characteristics can be different than the second set of characteristics. Now referring toFIGS.106A,107,108A, and109A, further to the above, the distance between thread windings on a drive screw can be proportional to the angle of threads on the drive screw. Put differently, the angle at which threads are arranged on a drive screw can be a characteristic of a drive screw that defines the thread pitch and/or thread lead of the drive screw. A longer drive screw for use in a longer end effector can utilize a larger thread pitch and/or thread lead than a shorter drive screw for use in a shorter end effector in embodiments where the drive screws, and a motor driving the drive screws, turn a fixed number of revolutions. The drive screw1700inFIG.106Aincludes a single thread A arranged at an angle α relative to the longitudinal axis1701on the drive screw1700wherein the thread A defines a thread pitch and/or thread lead having a length X.FIG.106Bshows a cross-sectional view of the drive screw1700and the single thread A. In certain embodiments, the drive screw1700may include more than one thread, as described in greater detail below. FIG.107Ashows a drive screw1700′ which can include a first thread A′ and a second thread B′.FIG.107Bshows a cross-sectional view of the drive screw1700′ wherein the first thread A′ and the second thread B′ are positioned approximately 180° out of phase with each other on the drive screw1700′. In various embodiments, a drive screw with a first thread A′ and a second thread B′ can increase the number of threads per unit length compared to a drive screw using a single thread A′ or B′. Where a drive screw includes more than one thread, the distance from a winding of a first thread to an adjacent winding of a second thread is referred to as “thread pitch.” The distance from one winding of a thread to the next winding of the same thread is referred to as “thread lead.” For a drive screw with a single thread, the thread pitch and the thread lead are the same. For example, and with reference toFIG.107A, the distance from a winding of thread A′ to an adjacent winding of thread B′ defines the thread pitch of the drive screw1700′. The distance from a winding of thread A′ to the next winding of thread A′ defines the thread lead of the drive screw1700′. Thus, the thread lead of the drive screw1700′ inFIG.107Ais equal to X′ and the thread pitch is equal to X′/2. The drive screw1700shown in FIGS.106A and106B has a single thread and therefore the thread pitch and thread lead are both equal to X. The thread lead of a drive screw determines the length that a firing member, such as a cutting blade1730and/or a staple driver, for example, will travel for a single revolution of the drive screw. Returning toFIG.107A, the first thread A′ and the second thread B′ each are arranged at an angle β relative to the longitudinal axis1701of the drive screw1700′. Angle β is less than angle α and the thread lead X′ of the drive screw1700′ inFIG.107Ais greater than the thread lead X of the drive screw1700shown inFIG.106A. For a single rotation of the drive screw1700′, a cutting blade will move a length X′ along the drive screw1700′. For example, the thread lead X′ can be double the thread pitch or thread lead X of the drive screw1700shown inFIG.106Awherein, as a result, a cutting blade engaged with the drive screw1700′ ofFIG.107Awill move twice the distance for a single revolution of drive screw1700′ as would a cutting blade engaged with the drive screw1700ofFIG.106A. FIG.108Ashows a drive screw1700″ which can include a first thread A″, a second thread B″, and a third thread C″ each extending at an angle γ relative to the longitudinal axis1701of the drive screw1700″.FIG.108Bis a cross-sectional view of the drive screw1700″ and shows the threads A″, B″, and C″ arranged approximately 120° out of phase. The angle γ is smaller than the angle β inFIG.107Aand the thread lead X″ of the drive screw1700″ inFIG.108Ais greater than the thread lead X′ of the drive screw1700′ shown inFIG.107A. Similarly,FIG.109Ashows a drive screw1700′″ which can include a first thread A′″, a second thread B′″, a third thread C′″, and a fourth thread D′″, each of which extends at an angle δ relative to the longitudinal axis Z of the drive screw1700′.FIG.109Bis a cross-sectional view of the drive screw1700′″ and shows the threads arranged approximately 90° out of phase. The angle δ is smaller than angle γ and the thread lead X′″ of the drive screw1700′″ is larger than that of drive screw1700″ inFIG.108A. An exemplary surgical instrument system may include a housing and a motor in the housing configured to turn a fixed number of revolutions that results in a drive screw of a connected replaceable end effector turning 30 revolutions, for example. The surgical instrument system can further include a plurality of replaceable surgical stapler end effectors, wherein each of the end effectors can include a cutting blade and/or staple driver driven by the drive screw, for example. In at least one such embodiment, a first replaceable end effector can include a staple cartridge having a length of 15 mm, for example. The drive screw1700shown inFIGS.2A and2Bcan be used in the first replaceable end effector. The thread lead X can be set to 0.5 mm, for example, so that the cutting blade and/or staple driver can travel the 15 mm length of the staple cartridge in the 30 revolutions of the drive screw1700. A second replaceable end effector can include a staple cartridge having a length of 30 mm, for example, and a drive screw, such as drive screw1700″ illustrated inFIGS.107A and107B, for example. The thread lead X′ of the drive screw1700′ can be set to 1.0 mm, for example, so that the cutting blade and/or staple drive can travel the 30 mm length of the staple cartridge in the 30 revolutions of the drive screw1700′. Similarly, a third replaceable end effector with a staple cartridge having a length of 45 mm, for example, can include a drive screw, such as drive screw1700″ inFIGS.108A and108B, having a thread lead X″ of 1.5 mm, for example, so that the cutting blade and/or staple drive travels the 45 mm length of the staple deck in the 30 revolutions of the drive screw1700″. A fourth replaceable end effector with a staple cartridge having a length of 60 mm, for example can include a drive screw, such as drive screw1700′″ inFIGS.109A and109B, having a thread lead X′″ of 2.0 mm, for example, so that the cutting blade and/or staple drive travels the 60 mm length of the staple deck in the 30 revolutions of the drive screw1700′″. FIG.110shows the cutting blade1730ofFIG.105removed from the remainder of the end effector1740. The cutting blade1730includes a passage1732though which the drive screw1700passes. Side portions1736form interior walls of the passage1732and can include recesses, such a grooves1734, for example, which are configured to receive threads1708on the drive screw1700. The grooves1734are oriented at an angle that corresponds to the angle of the threads1708on the drive screw1700. For example, if the threads1708are set to the angle α, shown inFIG.106A, then the angle of the grooves1734can also be set to the angle α. Correspondingly, the angle ε of the grooves1734can be set to the angles β, δ and/or γ, for example, of the corresponding drive screw used therewith. In various embodiments, as illustrated in the exploded view ofFIG.110, the side portions1736can be assembled into windows1738defined in a shaft portion1746of the cutting blade1730. In certain embodiments, a cutting blade1730can comprise integral side portions. In at least one embodiment, the side portions can comprise an appropriate groove angle matching an angle of the threads1708on a drive screw1700which can be formed in the passage1732defined therein. Providing a cutting blade1730with an appropriate groove angle for a particular drive screw can be accomplished in numerous ways. In certain embodiments, a generic cutting blade1730can be provided that does not include side portions1736assembled into the windows1738of the shaft portion1746thereof wherein various sets of side portions1736can be provided such that a desired set of side portions1736can be selected from the various sets of side portions1736and then assembled to the generic cutting blade1730so that such an assembly can be used with a specific drive screw. For instance, a first set of side portions1736, when assembled to the cutting blade1730, can configure the cutting blade1730to be used with a first drive screw and a second set of side portions1736, when assembled to the cutting blade1730, can configure the cutting blade1730to be used with a second drive screw, and so forth. In certain other embodiments, a cutting blade1730can be provided with side portions formed integrally therewith. In at least one such embodiment, the grooves1734can be formed, e.g., with a tap, at the angle that matches the angle of threads1708of a particular drive screw1700. FIG.111illustrates the drive screw1700coupled to a drive shaft1750via an intermediate gear1720disposed therebetween. The drive shaft1750is turned by a motor. As described above, the motor can complete a fixed or set number of revolutions and, as a result, the drive shaft1750can turn a fixed number of revolutions R. In certain embodiments, the number of revolutions R turned by the drive shaft1750may be equal to the fixed number of revolutions turned by the motor. In alternative embodiments, the number of revolutions R turned by the drive shaft1750may be greater than or less than the fixed number revolutions turned by the motor. In various embodiments, one or more gears arranged between the motor and the drive shaft1750can cause the drive shaft1750to complete more revolutions or fewer revolutions than the motor. In certain embodiments, the drive shaft1750can include an external spline gear1752surrounding and/or attached to the distal end1754of the drive shaft1750. The external spline gear1752can engage an internal spline gear1724defined in the intermediate gear1720in order to transmit rotation of the drive shaft1750to the intermediate gear1720. As a result, in at least one embodiment, the intermediate gear1720can complete the same revolutions R as the drive shaft1750. The intermediate gear1720can include a second gear1722that is engaged to a gear1712surrounding and/or attached to a proximal end1702of the drive screw1700. The second gear1722of the intermediate gear1720defines a first diameter D1and the gear1712on the proximal end1702of the drive screw1700defines a second diameter D2. The second diameter D2can be different than the first diameter D1. When the first diameter D1and the second diameter D2are different, they can define a gear ratio that is different than 1:1. As shown inFIG.111, in certain embodiments, diameter D1can be larger than diameter D2such that the drive screw1700will complete more revolutions R′ than the revolutions R turned by the drive shaft1750and the intermediate gear1720. In alternative embodiments, diameter D1can be smaller than diameter D2such that the drive screw1700will turn fewer revolutions R′ than the revolutions R turned by the drive shaft1750and the intermediate gear1720. The gear ratio between the second gear1722of the intermediate gear1720and the gear1712of the drive screw1700can be set so that the drive screw1700completes a certain number of revolutions when the drive shaft1750completes its fixed number of revolutions. If the intermediate gear1722is part of the replaceable end effector assembly, then the gear ratio between the intermediate gear1722and the drive screw1700in each replaceable end effector assembly can be set so that the motor in the surgical housing can turn a fixed number of revolutions. For example, referring toFIG.111, assuming that the drive shaft1750turns a fixed 30 revolutions and that the replaceable surgical stapler includes a 15 mm staple cartridge and if the end effector includes a drive screw with a thread lead of 0.25 mm, then the drive screw will complete 60 revolutions to advance a cutting blade and/or a staple driver the 15 mm length of the staple cartridge. In at least one embodiment, the intermediate gear1720can be sized so that the second interior gear1722has a diameter D1that is double the diameter D2of the external gear1712of the drive screw1700. As a result, the drive screw1700will complete 60 revolutions when the drive shaft1750completes 30 revolutions. If a second replaceable surgical stapler includes a 30 mm staple cartridge, then a drive screw with a thread lead of 0.25 mm will complete 120 revolutions to advance a cutting blade and/or staple driver the 30 mm length. The intermediate gear1720of the replaceable surgical stapler can be sized so that the second interior gear1722has a diameter D1that is four times the diameter D2of the external gear1712of the drive screw1700. As a result, the drive screw1700will complete 120 revolutions when the drive shaft1750completes 30 revolutions. Returning toFIG.105, in certain embodiments, a firing path of the firing member, e.g., cutting blade1730, can be linear. In certain embodiments, the firing patch can be curved and/or curvilinear. In certain embodiments, the drive screw1708can be flexible to enable the drive screw1708to follow lateral motions of the firing member along a curved and/or curvilinear path, for example. In certain embodiments, the firing member can be flexible or can include at least one flexible portion to enable portions of the firing member to displace laterally relative to the drive screw1708, for example, along a curved and/or curvilinear path while remaining portions of the firing member are not laterally displaced relative to the drive screw1708. In certain embodiments, the firing length may be defined by the distance moved by the firing member along the firing path regardless of the overall net displacement. In various other embodiments, the firing length may be defined by the overall net displacement of the firing member regardless of the firing path. In various embodiments, a kit for use with a surgical instrument system may be provided that includes various replaceable end effectors having different lengths. In certain embodiments, the kit may include a selection of replaceable end effectors having different lengths from which a surgeon may choose for use in a surgical operation on a patient. The kit can also include several replaceable end effectors of each length. In certain embodiments, the kit may include a sequence of replaceable end effectors of different lengths wherein the sequence is predetermined for a particular surgical procedure. For example, a certain surgical procedure first may call for a 15 mm incision, then a second 15 mm incision, and finally a 30 mm incision. A surgical kit for this surgical procedure can include three replaceable end effectors configured to incise and staple a patient's tissue. The first two replaceable end effectors can include an approximately 15 mm length and the third replaceable end effector can include an approximately 30 mm length. FIGS.112-117illustrate another exemplary elongate shaft assembly2200that has another exemplary quick disconnect coupler arrangement2210therein. In at least one form, for example, the quick disconnect coupler arrangement2210includes a proximal coupler member2212in the form of a proximal outer tube segment2214that has tube gear segment354thereon that is configured to interface with the first drive system350in the above-described manner. As discussed above, the first drive system350serves to rotate the elongate shaft assembly2200and the end effector1000operably coupled thereto about the longitudinal tool axis “LT-LT”. The proximal outer tube segment2214has a “necked-down” distal end portion2216that is configured to receive a locking tube segment2220thereon. The quick disconnect arrangement2210further includes a distal coupler member2217in the form of a distal outer tube portion2218that is substantially similar to the distal outer tube portion231described above except that the distal outer tube portion2218includes a necked down proximal end portion2219. A distal outer formation or dovetail joint2226is formed on the end of the proximal end portion2219of the distal outer tube segment2218that is configured to drivingly engage a proximal outer formation or dovetail joint2228that is formed on the distal end portion2216of the proximal outer tube segment2214. The exemplary embodiment depicted inFIGS.112-117employs an exemplary embodiment of the closure system670described above. The quick disconnect coupler arrangement2210is configured to facilitate operable coupling of proximal closure drive train assemblies to corresponding distal drive train assemblies. For example, as can be seen inFIG.113, the elongate shaft assembly2200may include a first proximal closure drive train assembly in the form of a first proximal closure rod segment2230and a first distal closure drive train assembly in the form of a first distal closure rod segment2240that are configured to be linked together through the quick disconnect coupler arrangement2210. That is, in at least one exemplary form, the first proximal closure rod segment2230has a first closure joint formation or dovetail joint segment2234formed on a distal end2232thereof. Likewise, the first distal closure rod segment2240has a second closure joint formation or a dovetail joint segment2244formed on a proximal end2242thereof that is adapted to laterally slidably engage the first dovetail joint segment2234. Still referring toFIG.113, the elongate shaft assembly2200may include a second proximal closure drive train assembly in the form of a second proximal closure rod segment2250and a second distal closure drive train assembly in the form of a second distal closure rod segment2260that are configured to be linked together through the quick disconnect coupler arrangement2210. That is, in at least one exemplary form, the second proximal closure rod segment2250has a third closure joint formation or dovetail closure joint segment2254formed on a distal end2252thereof. Likewise, the distal second distal closure rod segment2260may have a fourth closure joint formation or dovetail closure joint segment2264formed on a proximal end2262of the distal second closure rod segment2260that is adapted to laterally engage the third dovetail joint segment2254. In the illustrated embodiment and others, the first proximal closure rod segment2230and the second proximal closure rod segment2250extend through the proximal drive shaft segment380′. The proximal drive shaft segment380′ comprises a proximal rotary drive train assembly387′ and the distal drive shaft segment540′ comprises a distal rotary drive train assembly548′. When the proximal rotary drive train assembly387′ is operably coupled to the distal rotary drive train assembly548′, the drive shaft assembly388′ is formed to transmit rotary control motions to the end effector1000. In at least one exemplary embodiment, the proximal drive shaft segment380′ is substantially similar to the proximal drive shaft segment380described above, except that the distal end381′ of the proximal drive shaft segment380′ has a distal formation or dovetail drive joint2270formed thereon. Similarly, the distal drive shaft segment540′ may be substantially similar to the distal drive shaft segment540described above, except that a proximal formation dovetail drive joint2280is formed on the proximal end542′ thereof that is adapted to drivingly engage the distal dovetail drive joint2270through the quick disconnect coupler arrangement2210. The first distal closure rod segment2240and the distal second closure rod segment2260may also extend through the distal drive shaft segment540′. This exemplary embodiment may also include an articulation coupling joint2300that interfaces with the third and fourth drive cables434,454. As can be seen inFIG.113, the articulation coupling joint2300comprises a proximal articulation tube2302that has a proximal ball joint segment2306formed on a distal end2304thereof. The proximal articulation tube2302includes passages2308for receiving the cable end portions434A′,434B′,454A′,454B′ therethrough. A proximal ball joint segment2310is movably supported on the proximal ball segment2306. Proximal cable segments434A′,434B′,454A′,454B′ extend through passages2308to be attached to the proximal ball joint segment2310. The proximal articulation tube2302, the proximal ball joint segment2310and the proximal cable segments434A′,434B′,454A′,454B′ may be collectively referred to as a proximal articulation drive train portion2314. The exemplary articulation coupling joint2300may also comprise a distal articulation tube2320that has a distal ball joint segment2324formed on a proximal end2322thereof. The distal ball joint segment2324has a first distal formation or dovetail joint2325formed thereon that is adapted to drivingly engage a first proximal formation or dovetail joint2307formed on the proximal ball joint segment2306such that when the first distal dovetail joint2325drivingly engages the first proximal dovetail joint2307, the distal ball joint segment2324and the proximal ball joint segment2306form an internal articulation ball assembly. In addition, the articulation coupling joint2300further comprises a distal ball segment2330that is supported on the distal ball joint segment2324and has a second distal formation or dovetail joint2332formed thereon that is adapted to drivingly engage a second proximal formation or dovetail joint2312on the proximal ball joint segment2310. The distal cable segments444,445,446,447are attached to the distal ball segment2340and extend through passages2328in the distal articulation tube2320. When joined together, the proximal ball joint segment2310and the distal ball joint segment2324form an articulation ball2340that is movably journaled on the internal articulation ball. The distal articulation tube2320, the distal ball segment2340and the distal cable segments444,445,446,4447may be collectively referred to as a proximal articulation drive train assembly2316. As can be seen inFIG.115, the distal portions of the elongate shaft assembly2200may be assembled such that the following joint segments are retained in registration with each other by the distal coupler2217or distal outer tube portion2218to form a distal dovetail joint assembly generally referred to as2290:2226,2332,2325,2280,2244and2264. Likewise, the elongate shaft assembly2200may be assembled such that the proximal coupler member2212or proximal outer tube segment2214retains the following joint segments in registration with each other to form a proximal dovetail joint assembly generally designated as2292:2228,2312,2307,2270,2234and2254. The end effector1000may be operably coupled to the elongate shaft assembly2200as follows. To commence the attachment, the clinician moves the locking tube segment2220to a first unlocked position shown inFIGS.115and116. As can be seen in those Figures, the locking tube segment has an abutment segment2224formed on its distal end2222. When in the unlocked position, the abutment segment2224protrudes distally beyond the proximal dovetail joint assembly2292to form an abutment surface for laterally joining the distal dovetail joint assembly2290with the proximal dovetail joint assembly2292. That is, the clinician may laterally align the distal dovetail joint assembly2290with the proximal dovetail joint assembly2292and then slide the distal dovetail joint assembly2290into lateral engagement with the proximal dovetail joint assembly2292until the distal dovetail joint assembly2290contacts the abutment segment2224at which point all of the corresponding proximal and distal joint segments are simultaneously interconnected. Thereafter, the clinician may move the locking tube segment2220distally to a second locked position as shown inFIG.117. When in that position, the locking tube segment2220covers the quick disconnect joint2210and prevents any relative lateral movement between the distal dovetail assembly2290and the proximal dovetail assembly2292. While the various exemplary embodiments described above are configured to operably interface with and be at least partially actuated by a robotic system, the end effector and elongate shaft components may be effectively employed in connection with handheld instruments. For example,FIGS.118-120depict a handheld surgical instrument2400that may employ various components and systems described above to operably actuate an end effector1000coupled thereto. In the exemplary embodiment depicted inFIGS.118-120, a quick disconnect joint2210is employed to couple the end effector1000to the elongate shaft assembly2402. To facilitate articulation of the end effector1000about the articulation joint700, the proximal portion of the elongate shaft assembly2402includes an exemplary manually actuatable articulation drive2410. Referring now toFIGS.121-123, in at least one exemplary form, the articulation drive2410includes four axially movable articulation slides that are movably journaled on the proximal drive shaft segment380′ between the proximal outer tube segment2214and the proximal drive shaft segment380′. For example, the articulation cable segment434A′ is attached to a first articulation slide2420that has a first articulation actuator rod2422protruding therefrom. Articulation cable segment434B′ is attached to a second articulation slide2430that is diametrically opposite from the first articulation slide2420. The second articulation slide2430has a second articulation actuator rod2432protruding therefrom. Articulation cable segment454A′ is attached to a third articulation slide2440that has a third articulation actuator rod2442protruding therefrom. Articulation cable segment454B′ is attached to a fourth articulation slide2450that is diametrically opposite to the third articulation slide2440. A fourth articulation actuator rod2452protrudes from the fourth articulation slide2450. Articulation actuator rods2422,2432,2442,2452facilitate the application of articulation control motions to the articulation slides2420,2430,2440,2450, respectively by an articulation ring assembly2460. As can be seen inFIG.121, the articulation actuator rods2422,2432,2442,2452movably pass through a mounting ball2470that is journaled on a proximal outer tube segment2404. In at least one embodiment, the mounting ball2470may be manufactured in segments that are attached together by appropriate fastener arrangements (e.g., welding, adhesive, screws, etc.). As shown inFIG.109, the articulation actuator rods2422and2432extend through slots2472in the proximal outer tube segment2404and slots2474in the mounting ball2470to enable the articulation slides2420,2430to axially move relative thereto. Although not shown, the articulation actuator rods2442,2452extend through similar slots2472,2474in the proximal outer tube segment2404and the mounting ball2470. Each of the articulation actuator rods2422,2432,2442,2452protrude out of the corresponding slots2474in the mounting ball2470to be operably received within corresponding mounting sockets2466in the articulation ring assembly2460. SeeFIG.122. In at least one exemplary form, the articulation ring assembly2460is fabricated from a pair of ring segments2480,2490that are joined together by, for example, welding, adhesive, snap features, screws, etc. to form the articulation ring assembly2460. The ring segments2480,2490cooperate to form the mounting sockets2466. Each of the articulation actuator rods has a mounting ball2468formed thereon that are each adapted to be movably received within a corresponding mounting socket2466in the articulation ring assembly2460. Various exemplary embodiments of the articulation drive2410may further include an exemplary locking system2486configured to retain the articulation ring assembly2460in an actuated position. In at least one exemplary form, the locking system2486comprises a plurality of locking flaps formed on the articulation ring assembly2460. For example, the ring segments2480,2490may be fabricated from a somewhat flexible polymer or rubber material. Ring segment2480has a series of flexible proximal locking flaps2488formed therein and ring segment2490has a series of flexible distal locking flaps2498formed therein. Each locking flap2388has at least one locking detent2389formed thereon and each locking flap2398has at least one locking detent2399thereon. Locking detents2389,2399may serve to establish a desired amount of locking friction with the articulation ball so as to retain the articulation ball in position. In other exemplary embodiments, the locking detents2389,2390are configured to matingly engage various locking dimples formed in the outer perimeter of the mounting ball2470. Operation of the articulation drive2410can be understood from reference toFIGS.122and123.FIG.122illustrates the articulation drive2410in an unarticulated position. InFIG.123, the clinician has manually tilted the articulation ring assembly2460to cause the articulation slide2420to move axially in the distal direction “DD” thereby advancing the articulation cable segment434A′ distally. Such movement of the articulation ring assembly2460also results in the axial movement of the articulation slide2430in the proximal direction which ultimately pulls the articulation cable434B in the proximal direction. Such pushing and pulling of the articulation cable segments434A′,434B′ will result in articulation of the end effector1000relative to the longitudinal tool axis “LT-LT” in the manner described above. To reverse the direction of articulation, the clinician simply reverses the orientation of the articulation ring assembly2460to thereby cause the articulation slide2430to move in the distal direction “DD” and the articulation slide2420to move in the proximal direction “PD”. The articulation ring assembly2460may be similarly actuated to apply desired pushing and pulling motions to the articulation cable segments454A′,454B′. The friction created between the locking detents2389,2399and the outer perimeter of the mounting ball serves to retain the articulation drive2410in position after the end effector1000has been articulated to the desired position. In alternative exemplary embodiments, when the locking detents2389,2399are positioned so as to be received in corresponding locking dimples in the mounting ball, the mounting ball will be retained in position. In the illustrated exemplary embodiments and others, the elongate shaft assembly2402operably interfaces with a handle assembly2500. An exemplary embodiment of handle assembly2500comprises a pair of handle housing segments2502,2504that are coupled together to form a housing for various drive components and systems as will be discussed in further detail below. See, e.g.,FIGS.118and119. The handle housing segments2502,2504may be coupled together by screws, snap features, adhesive, etc. When coupled together, the handle segments2502,2504may form a handle assembly2500that includes a pistol grip portion2506. To facilitate selective rotation of the end effector1000about the longitudinal tool axis “LT=LT”, the elongate shaft assembly2402may interface with a first drive system, generally designated as2510. The drive system2510includes a manually-actuatable rotation nozzle2512that is rotatably supported on the handle assembly2500such that it can be rotated relative thereto as well as be axially moved between a locked position and an unlocked position. The surgical instrument2400may include a closure system670as was described above for applying opening and closing motions to the anvil1100of the end effector1000. In this exemplary embodiment, however, the closure system670is actuated by a closure trigger2530that is pivotally mounted to the handle frame assembly2520that is supported within the handle housing segments2502,2504. The closure trigger2530includes an actuation portion2532that is pivotally mounted on a pivot pin2531that is supported within the handle frame assembly2520. SeeFIG.124. Such exemplary arrangement facilitates pivotal travel toward and away from the pistol grip portion2506of the handle assembly2500. As can be seen inFIG.124, the closure trigger2530includes a closure link2534that is linked to the first pivot link and gear assembly695by a closure wire2535. Thus, by pivoting the closure trigger2530toward the pistol grip portion2506of the handle assembly2500into an actuated position, the closure link2534and closure wire2535causes the first pivot link and gear assembly695to move the first closure rod segment680in the distal direction “DD” to close the anvil. The surgical instrument2400may further include a closure trigger locking system2536to retain the closure trigger in the actuated position. In at least one exemplary form, the closure trigger locking system2536includes a closure lock member2538that is pivotally coupled to the handle frame assembly2520. As can be seen inFIGS.125and126, the closure lock member2538has a lock arm2539formed thereon that is configured to ride upon an arcuate portion2537of the closure link2532as the closure trigger2530is actuated toward the pistol grip portion2506. When the closure trigger2530has been pivoted to the fully actuated position, the lock arm2539drops behind the end of the closure link2532and prevents the closure trigger2530from returning to its unactuated position. Thus, the anvil1100will be locked in its closed position. To enable the closure trigger2530to return to its unactuated position and thereby result in the movement of the anvil from the closed position to the open position, the clinician simply pivots the closure lock member2538until the lock arm2539thereof disengages the end of the closure link2532to thereby permit the closure link2532to move to the unactuated position. The closure trigger2532is returned to the unactuated position by a closure return system2540. For example, as can be seen inFIG.124, one exemplary form of the closure trigger return system2540includes a closure trigger slide member2542that is linked to the closure link2534by a closure trigger yoke2544. The closure trigger slide member2542is slidably supported within a slide cavity2522in the handle frame assembly2520. A closure trigger return spring2546is positioned within the slide cavity2520to apply a biasing force to the closure trigger slide member2542. Thus, when the clinician actuates the closure trigger2530, the closure trigger yoke2544moves the closure trigger slide member2542in the distal direction “DD” compressing the closure trigger return spring2546. When the closure trigger locking system2536is disengaged and the closure trigger is released2530, the closure trigger return spring2546moves the closure trigger slide member2542in the proximal direction “PD” to thereby pivot the closure trigger2530into the starting unactuated position. The surgical instrument2400can also employ any of the various exemplary drive shaft assemblies described above. In at least one exemplary form, the surgical instrument2400employs a second drive system2550for applying rotary control motions to a proximal drive shaft assembly380′. SeeFIG.128. The second drive system2550may include a motor assembly2552that is operably supported in the pistol grip portion2506. The motor assembly2552may be powered by a battery pack2554that is removably attached to the handle assembly2500or it may be powered by a source of alternating current. A second drive gear2556is operably coupled to the drive shaft2555of the motor assembly2552. The second drive gear2556is supported for meshing engagement with a second rotary driven gear2558that is attached to the proximal drive shaft segment380′ of the drive shaft assembly. In at least one form, for example, the second drive gear2556is also axially movable on the motor drive shaft2555relative to the motor assembly2552in the directions represented by arrow “U” inFIG.128. A biasing member, e.g., a coil spring2560or similar member, is positioned between the second drive gear2556and the motor housing2553and serves to bias the second drive gear2556on the motor drive shaft2555into meshing engagement with a first gear segment2559on the second driven gear2558. The second drive system2550may further include a firing trigger assembly2570that is movably, e.g., pivotally attached to the handle frame assembly2520. In at least one exemplary form, for example, the firing trigger assembly2570includes a first rotary drive trigger2572that cooperates with a corresponding switch/contact (not shown) that electrically communicates with the motor assembly2552and which, upon activation, causes the motor assembly2552to apply a first rotary drive motion to the second driven gear2558. In addition, the firing trigger assembly2570further includes a retraction drive trigger2574that is pivotal relative to the first rotary drive trigger. The retraction drive trigger2574operably interfaces with a switch/contact (not shown) that is in electrical communication with the motor assembly2552and which, upon activation, causes the motor assembly2552to apply a second rotary drive motion to the second driven gear2558. The first rotary drive motion results in the rotation of the drive shaft assembly and the implement drive shaft in the end effector to cause the firing member to move distally in the end effector1000. Conversely, the second rotary drive motion is opposite to the first rotary drive motion and will ultimately result in rotation of the drive shaft assembly and the implement drive shaft in a rotary direction which results in the proximal movement or retraction of the firing member in the end effector1000. The illustrated embodiment also includes a manually actuatable safety member2580that is pivotally attached to the closure trigger actuation portion2532and is selectively pivotable between a first “safe” position wherein the safety member2580physically prevents pivotal travel of the firing trigger assembly2570and a second “off” position, wherein the clinician can freely pivot the firing trigger assembly2570. As can be seen inFIG.124, a first dimple2582is provided in the closure trigger actuation portion2532that corresponds to the first position of the safety member2580. When the safety member2580is in the first position, a detent (not shown) on the safety member2580is received within the first dimple2582. A second dimple2584is also provided in the closure trigger actuation portion2532that corresponds to the second position of the safety member2580. When the safety member2580is in the second position, the detent on the safety member2580is received within the second dimple2582. In at least some exemplary forms, the surgical instrument2400may include a mechanically actuatable reversing system, generally designated as2590, for mechanically applying a reverse rotary motion to the proximal drive shaft segment380′ in the event that the motor assembly2552fails or battery power is lost or interrupted. Such mechanical reversing system2590may also be particularly useful, for example, when the drive shaft system components operably coupled to the proximal drive shaft segment380′ become jammed or otherwise bound in such a way that would prevent reverse rotation of the drive shaft components under the motor power alone. In at least one exemplary form, the mechanically actuatable reversing system2590includes a reversing gear2592that is rotatably mounted on a shaft2524A formed on the handle frame assembly2520in meshing engagement with a second gear segment2562on the second driven gear2558. SeeFIG.126. Thus, the reversing gear2592freely rotates on shaft2524A when the second driven gear2558rotates the proximal drive shaft segment380′ of the drive shaft assembly. In various exemplary forms, the mechanical reversing system2590further includes a manually actuatable driver2594in the form of a lever arm2596. As can be seen inFIGS.129and130, the lever arm2596includes a yoke portion2597that has elongate slots2598therethrough. The shaft2524A extends through slot2598A and a second opposing shaft2598B formed on the handle housing assembly2520extends through the other elongate slot to movably affix the lever arm2596thereto. In addition, the lever arm2596has an actuator fin2597formed thereon that can meshingly engage the reversing gear2592. There is a detent or interference that keeps the lever arm2596in the unactuated state until the clinician exerts a substantial force to actuate it. This keeps it from accidentally initiating if inverted. Other embodiments may employ a spring to bias the lever arm into the unactuated state. Various exemplary embodiments of the mechanical reversing system2590further includes a knife retractor button2600that is movably journaled in the handle frame assembly2520. As can be seen inFIGS.129and130, the knife retractor button2600includes a disengagement flap2602that is configured to engage the top of the second drive gear2556. The knife retractor button2600is biased to a disengaged position by a knife retractor spring2604. When in the disengaged position, the disengagement flap2602is biased out of engagement with the second drive gear2556. Thus, until the clinician desires to activate the mechanical reversing system2590by depressing the knife retractor button2600, the second drive gear2556is in meshing engagement with the first gear segment2559of the second driven gear2558. When the clinician desires to apply a reverse rotary drive motion to the proximal drive shaft segment380′, the clinician depresses the knife retractor button2600to disengage the first gear segment2559on the second driven gear2558from the second drive gear2556. Thereafter, the clinician begins to apply a pivotal ratcheting motion to the manually actuatable driver2594which causes the gear fin2597thereon to drive the reversing gear2592. The reversing gear2592is in meshing engagement with the second gear segment2562on the second driven gear2558. Continued ratcheting of the manually actuatable driver2594results in the application of a reverse rotary drive motion to the second gear segment2562and ultimately to the proximal drive shaft segment380′. The clinician may continue to ratchet the driver2594for as many times as are necessary to fully release or reverse the associated end effector component(s). Once a desired amount of reverse rotary motion has been applied to the proximal drive shaft segment380′, the clinician releases the knife retractor button2600and the driver2594to their respective starting or unactuated positions wherein the fin2597is out of engagement with the reversing gear2592and the second drive gear2556is once again in meshing engagement with the first gear segment2559on the second driven gear2558. The surgical instrument2400can also be employed with an end effector1000that includes a rotary transmission750as was described in detail above. As discussed above, when the drive shaft assembly is in a first axial position, rotary motion applied thereto results in the rotation of the entire end effector1000about the longitudinal tool axis “LT-LT” distal to the articulation joint700. When the drive shaft assembly is in the second position, rotary motion applied thereto results in the rotation of the implement drive shaft which ultimately causes the actuation of the firing member within the end effector1000. The surgical instrument2400may employ a shifting system2610for selectively axially shifting the proximal drive shaft segment380′ which moves the shaft gear376into and out of meshing engagement with the first rotary driven gear374. For example, the proximal drive shaft segment380′ is movably supported within the handle frame assembly2520such that the proximal drive shaft segment380′ may move axially and rotate therein. In at least one exemplary form, the shifting system2610further includes a shifter yoke2612that is slidably supported by the handle frame assembly2520. SeeFIGS.124and127. The proximal drive shaft segment380′ has a pair of collars386(shown inFIGS.124and128) thereon such that shifting of the shifter yoke2612on the handle frame assembly2520results in the axial movement of the proximal drive shaft segment380′. In at least one form, the shifting system2610further includes a shifter button assembly2614operably interfaces with the shifter yoke2612and extends through a slot2505in the handle housing segment2504of the handle assembly2500. SeeFIGS.135and136. A shifter spring2616is mounted with the handle frame assembly2520such that it engages the proximal drive shaft segment380′. SeeFIGS.127and134. The spring2616serves to provide the clinician with an audible click and tactile feedback as the shifter button assembly2614is slidably positioned between the first axial position depicted inFIG.135wherein rotation of the drive shaft assembly results in rotation of the end effector1000about the longitudinal tool axis “LT-LT” relative to the articulation joint700(illustrated inFIG.67) and the second axial position depicted inFIG.136wherein rotation of the drive shaft assembly results in the axial movement of the firing member in the end effector (illustrated inFIG.66). Thus, such arrangement enables the clinician to easily slidably position the shifter button assembly2614while holding the handle assembly2500. FIGS.137-147illustrate a lockable articulation joint2700that, in one exemplary embodiment, is substantially identical to the articulation joint700described above except for the differences discussed below. In one exemplary embodiment, the articulation joint2700is locked and unlocked by an articulation lock system2710. The articulation joint2700includes a proximal socket tube702that is attached to the distal end233of the distal outer tube portion231and defines a proximal ball socket704therein. SeeFIG.137. A proximal ball member706that is attached to an intermediate articulation tube segment712is movably seated within the proximal ball socket704within the proximal socket tube702. As can be seen inFIG.137, the proximal ball member706has a central drive passage708that enables the distal drive shaft segment540to extend therethrough. In addition, the proximal ball member706has four articulation passages710therein which facilitate the passage of distal cable segments444,445,446,447therethrough. As can be further seen inFIG.137, the intermediate articulation tube segment712has an intermediate ball socket714formed therein. The intermediate ball socket714is configured to movably support therein an end effector ball722formed on an end effector connector tube720. The distal cable segments444,445,446,447extend through cable passages724formed in the end effector ball722and are attached thereto by lugs726received within corresponding passages728in the end effector ball722. Other attachment arrangements may be employed for attaching distal cable segments444,445,446,447to the end effector ball722. As can be seen inFIG.137, one exemplary form of the articulation lock system2710includes a lock wire or member2712that extends through the distal outer tube portion231of elongate shaft assembly and the proximal socket tube702. The lock wire2712has a proximal end2720that is attached to a transfer disc2722that is operably supported in the handle portion2500(generally represented in broken lines inFIG.137). For example, the transfer disc2722is mounted on a spindle shaft2724that is coupled to a boss2726formed in the handle2500. An actuator cable or wire2730is attached to the transfer disc2722and may be manually actuated (i.e., pushed or pulled) by the clinician. In other embodiments wherein the surgical instrument is attached to the robotic system, the actuator cable2730may be configured to receive control motions from the robotic system to actuate the transfer disc2722. As can be seen inFIGS.143-146, the lock wire2712has a pair of unlocking wedges2714,2716formed on its distal end2715. The first unlocking wedge2714is configured to operably interface with the ends2742,2744of a distal locking ring2740that is journaled on the intermediate articulation tube712. In its normal “locked” state as shown inFIG.143, the distal locking ring2740applies a circumferentially-extending locking or squeezing force to the intermediate articulation tube712to squeeze the intermediate articulation tube712onto the end effector ball722to prevent its movement within the socket714. As can be seen inFIGS.143-146, the ends2742,2744of the distal locking ring2740are tapered to define a conical or V-shaped opening2746therebetween configured to receive the first unlocking wedge2714therebetween. As can be further seen inFIGS.143-146, the second locking wedge2716is configured to interface with the ends2752,2754of a proximal locking ring2750that is journaled on the proximal socket tube702. In its normal “locked” state as shown inFIG.143, the proximal locking ring27450applies a circumferentially-extending locking or squeezing force to the proximal socket tube702to squeeze the proximal socket tube702onto the proximal ball member706to prevent its movement within the proximal ball socket704. As can be seen inFIGS.143-146, the ends2752,2754of the proximal locking ring2750are tapered to define a conical or V-shaped opening2756therebetween configured to receive the second unlocking wedge2716therebetween. When the articulation joint2700is unlocked by actuation the articulation lock system2710, the end effector1000may be selectively articulated in the various manners described above by actuating the distal cable segments444,445,446,447. Actuation of the articulation lock system2710may be understood from reference toFIGS.138,139and143-146.FIG.143depicts the positions of the first and second unlocking wedges2714,2716with respect to the distal and proximal locking rings2740,2750. When in that state, locking ring2740prevents movement of the end effector ball722within the socket714and the locking ring2750prevents the proximal ball member706from moving within socket704. To unlock the articulation joint2700, the actuation cable2726is pulled in the proximal direction “PD” which ultimately results in the locking wire2712being pushed in the distal direction “DD” to the position shown inFIG.144. As can be seen inFIG.144, the first unlocking wedge2714has moved distally between the ends2742,2744of the distal locking ring2740to spread the ring2740to relieve the squeezing force applied to the intermediate articulation tube712to permit the end effector ball722to move within the socket714. Likewise, the second unlocking wedge2716has moved distally between the ends2752,2754of the proximal locking ring2750to spread the ring2750to relieve the squeezing force on the proximal socket tube702to permit the proximal ball member706to move within the socket704. When in that unlocked position, the articulation system may be actuated to apply actuation motions to the distal cable segments444,445,446,447in the above described manners to articulate the end effector1000as illustrated inFIGS.138and139. For example,FIGS.143and144illustrate the position of the first and second locking wedges2714,2716when the end effector1000has been articulated into the position illustrated inFIG.138. Likewise,FIGS.145,146illustrate the position of the first and second locking wedges2714,2716when the end effector1000has been articulated into the position illustrated inFIG.139. Once the clinician has articulated the end effector to the desired position, the clinician (or robotic system) applies a pushing motion to the actuation cable to rotate the transfer disc2722and move the locking wire2712to the position shown inFIGS.143,145to thereby permit the locking rings2740,2750to spring to their clamped or locked positions to retain the end effector1000in that locked position. FIGS.148-156illustrate another end effector embodiment2800that, in one exemplary form, is substantially identical to the end effector1000except for the differences discussed below. The end effector2800includes an anvil assembly2810that is opened and closed by applying a rotary closure motion thereto. The anvil assembly2810is pivotally supported on an elongate channel2830for selective movement between an open position (FIGS.148and149) and a closed position (FIGS.150-153). The elongate channel2830may be substantially identical to elongate channel1020described above, except for the differences discussed below. For example, in the illustrated embodiment, the elongate channel2830has an end effector connector housing2832formed thereon that may be coupled to an end effector connector tube720by the ring-like bearing734as described above. As can be seen inFIG.148, the end effector connector housing2832operably supports a rotary transmission assembly2860therein. As can be seen inFIGS.148and149, the anvil assembly2810includes a pair of anvil trunnions2812(only one trunnion can be seen inFIG.148) that are movably received within corresponding trunnion slots2814formed in the elongate channel2830. The underside of the anvil assembly2810further has an anvil open ramp2816formed thereon for pivotal engagement with an anvil pivot pin1201′ on the firing member1200′. Firing member1200′ may be substantially identical to firing member1200described above except for the noted differences. In addition, the anvil assembly2810further includes a closure pin2818that is configured for operable engagement with a rotary closure shaft2910that receives rotary closure motions from the rotary transmission assembly2860as will be discussed in further detail below. The firing member1200′ is rotatably journaled on an implement drive shaft1300that is rotatably supported within an elongate channel2830that is configured to support a surgical staple cartridge therein (not shown). The implement drive shaft1300has a bearing segment1304formed thereon that is rotatably supported in a bearing sleeve2834formed in the end effector connector housing2832. In the exemplary illustrated embodiment, the rotary transmission assembly2860includes a rotary drive shaft2870that extends longitudinally through the elongate shaft assembly to operably interface with the tool mounting portion (if the end effector2800is powered by a robotic system) or with the firing trigger of a handle assembly (if the end effector2800is to be manually operated). For those embodiments employing an articulation joint, the portion of the rotary drive shaft2870that extends through the articulation joint700may comprise any of the flexible drive shaft assemblies disclosed herein. If no articulation joint is employed, the rotary drive shaft may be rigid. As can be most particularly seen inFIGS.148and149the rotary drive shaft2870has a rotary drive head2872formed thereon or attached thereto that has a first ring gear2874formed thereon. In addition, the rotary drive head2872further has a second ring gear2876formed thereon for selective meshing engagement with a shifter gear2882attached to a rotary shifter shaft2880. The shifter shaft2880may comprise any one of the rotary drive shaft assemblies described above and extends through the elongate shaft assembly to operably interface with a tool mounting portion300(if the end effector2800is driven by a robotic system) or the handle assembly (if the end effector is to be manually operated). In either case, the shifter shaft2800is configured to receive longitudinally shifting motions to longitudinally shift the shifter gear2882within the rotary drive head2872and rotary drive motions to rotate the shifter gear2882as will be discussed in further detail below. As can be further seen inFIGS.148and149, the rotary transmission assembly2860further includes a transfer gear assembly2890that has a body2892, a portion of which is rotatably supported within a cavity2873in the rotary drive head2872. The body2892has a spindle2894that rotatably extends through a spindle mounting hole2838formed in a bulkhead2836in the end effector connector housing2832. The body2892further has a shifter ring gear2896formed therein for selective meshing engagement with the shifter gear2882on the rotary shifter shaft2880. A transfer gear2900is mounted to a transfer gear spindle2902that protrudes from the body2892and is slidably received within the arcuate slot2840in the bulkhead2836. SeeFIGS.155and156. The transfer gear2900is in meshing engagement with the first ring gear2874formed in the rotary drive head2872. As can be seen inFIGS.153-156, the arcuate slot2840that has a centrally disposed flexible detent2842protruding therein. The detent2842is formed on a web2844formed by a detent relief slot2846formed adjacent to the arcuate slot2840as shown inFIG.155. The rotary closure shaft2910has a bearing portion2912that is rotatably supported through a corresponding opening in the bulkhead2836. The rotary closure shaft2910further has a closure drive gear2914that is configured for selective meshing engagement with the transfer gear2900. The implement drive shaft1300also has an implement drive gear1302that is configured for selective meshing engagement with the transfer gear2900. Operation of the end effector2800will now be explained with reference toFIGS.148-155.FIGS.148and149illustrate the end effector2800with the anvil assembly2810in the open position. To move the anvil assembly2810to the closed position shown inFIG.150, the shifter shaft2880is located such that the shifter gear2882is in meshing engagement with the shifter ring gear2896in the body2892. The shifter shaft2880may be rotated to cause the body2892to rotate to bring the transfer gear2900into meshing engagement with the closure drive gear2914on the closure shaft2910. SeeFIG.153. When in that position, the locking detent2842retains the transfer gear spindle2902in that position. Thereafter, the rotary drive shaft2870is rotated to apply rotary motion to the transfer gear2900which ultimately rotates the closure shaft2910. As the closure shaft2910is rotated, a rotary spindle portion2916which is in engagement with the closure pin2818on the anvil assembly2810results in the anvil assembly2810moving proximally causing the anvil assembly2810to pivot on the anvil pivot pin1201′ on the firing member1200′. Such action causes the anvil assembly2810to pivot to the closed position shown inFIG.150. When the clinician desires to drive the firing member1200′ distally down the elongate channel2830, the shifter shaft2880is once again rotated to pivot the transfer gear spindle2902to the position shown inFIG.154. Again, the locking detent2842retains the transfer gear spindle2902in that position. Thereafter, the rotary drive shaft2870is rotated to apply rotary motion to the drive gear1302on the implement drive shaft1300. Rotation of the implement drive shaft1300in one direction causes the firing member1200′ to be driven in the distal direction “DD”. Rotation of the implement drive shaft1300in an opposite direction will cause the firing member1200′ to be retracted in the proximal direction “PD”. Thus, in those applications wherein the firing member1200′ is configured to cut and fire staples within a staple cartridge mounted in the elongate channel2830, after the firing member1200′ has been driven to its distal-most position within the elongate channel2830, the rotary drive motion applied to the implement drive shaft1300by the rotary drive shaft assembly2870is reversed to retract the firing member1200′ back to its starting position shown inFIG.150. To release the target tissue from the end effector2800, the clinician again rotates the shifter shaft2800to once again bring the transfer gear2900into meshing engagement with the drive gear2914on the closure drive shaft2910. Thereafter, a reverse rotary motion is applied to the transfer gear2900by the rotary drive shaft2870to cause the closure drive shaft2910to rotate the drive spindle2916and thereby cause the anvil assembly2810to move distally and pivot to the open position shown inFIGS.148and149. When the clinician desires to rotate the entire end effector2800about the longitudinal tool axis “LT-LT”, the shifter shaft is longitudinally shifted to bring the shifter gear2882into simultaneously meshing engagement with the second ring gear2876on the rotary drive head2872and the shifter ring gear2896on the transfer gear body2892as shown inFIG.152. Thereafter, rotating the rotary drive shaft2880causes the entire end effector2800to rotate about the longitudinal tool axis “LT-LT” relative to the end effector connector tube720. FIGS.157-170illustrate another end effector embodiment3000that employs a pull-type motions to open and close the anvil assembly3010. The anvil assembly3010is movably supported on an elongate channel3030for selective movement between an open position (FIGS.168and169) and a closed position (FIGS.157,160and170). The elongate channel3030may be substantially identical to elongate channel1020described above, except for the differences discussed below. The elongate channel3030may be coupled to an end effector drive housing1010in the manner described above. The end effector drive housing1010may also be coupled to an end effector connector tube720by the ring-like bearing734as described above. As can be seen inFIG.157, the end effector drive housing1010may support a drive arrangement748and rotary transmission750as described above. As can be seen inFIG.160, the anvil assembly3010includes a pair of anvil trunnions3012(only one trunnion can be seen inFIG.160) that are movably received within corresponding trunnion slots3032formed in the elongate channel3030. The underside of the anvil assembly2810further has an anvil open notches3016formed thereon for pivotal engagement with the upper fins1208on the firing member3100. SeeFIG.168. Firing member3100may be substantially identical to firing member1200described above except for the noted differences. In the illustrated embodiment, the end effector3000further includes an anvil spring3050that is configured to apply a biasing force on the anvil trunnions3012. One form of anvil spring3050is illustrated inFIG.159. As can be seen in that Figure, the anvil spring3050may be fabricated from a metal wire and have two opposing spring arms3052that are configured to bear upon the anvil trunnions3012when the anvil trunnions are received within their respective trunnion slots3032. in addition, as can be further seen inFIG.159, the anvil spring3050has two mounting loops3054formed therein that are adapted to be movably supported on corresponding spring pins3034formed on the elongate channel3030. SeeFIG.158. As will be discussed in further detail below, the anvil spring3050is configured to pivot on the spring pins3034within the elongate channel3030. As can be most particularly seen inFIG.158, a portion3035of each side wall of the elongate channel is recessed to provide clearance for the movement of the anvil spring3050. As can be seen inFIGS.157and160-170, the end effector3000further includes a closure tube3060that is movably supported on the elongate channel3030for selective longitudinal movement thereon. To facilitate longitudinal movement of the closure tube3060, the embodiment depicted inFIGS.157and160-170includes a closure solenoid3070that is linked to the closure tube3060by a linkage arm3072that is pivotally pinned or otherwise attached to the closure tube3030. When the solenoid is actuated, the linkage arm3072is driven in the distal direction which drives the closure tube3060distally on the end of the elongate channel3030. As the closure tube3060moves distally, it causes the anvil assembly3010to pivot to a closed position. In an alternative embodiment, the solenoid may comprise an annular solenoid mounted on the distal end of the end effector drive housing1010. The closure tube would be fabricated from a metal material that could be magnetically attracted and repelled by the annular solenoid to result in the longitudinal movement of the closure tube. In at least one form, the end effector3060further includes a unique anvil locking system3080to retain the anvil assembly3010locked in position when it is closed onto the target tissue. In one form, as can be seen inFIG.157, the anvil locking system3080includes an anvil lock bar3082that extends transversely across the elongate channel3030such that the ends thereof are received within corresponding lock bar windows3036formed in the elongate channel3030. SeeFIG.158. Referring toFIG.161, when the closure tube3060is in its distal-most “closed” position, the ends of the lock bar3082protrude laterally out through the lock bar windows3036and extend beyond the proximal end of the closure tube3060to prevent it from moving proximally out of position. The lock bar3082is configured to engage a solenoid contact3076supported in the end effector drive housing1010. The solenoid contact3076is wired to a control system for controlling the solenoid3070. The control system includes a source of electrical power either supplied by a battery or other source of electrical power in the robotic system or handle assembly, whichever the case may be. The firing member3100is rotatably journaled on an implement drive shaft1300that is rotatably supported within an elongate channel2830that is configured to support a surgical staple cartridge therein (not shown). The implement drive shaft1300has a bearing segment1304formed thereon that is rotatably supported in a bearing sleeve2834formed in the end effector connector housing2832and operably interfaces with the rotary transmission750in the manner described above. Rotation of the implement drive shaft1300in one direction causes the firing member3100to be driven distally through the elongate channel3030and rotation of the implement drive shaft1300in an opposite rotary direction will cause the firing member1200″ to be retracted in the proximal direction “PD”. As can be seen inFIGS.157and160-170, the firing member3100has an actuation bar3102configured to engage the lock bar3082as will be discussed in further detail below. The anvil locking system3080further includes an anvil pulling assembly3090for selectively pulling the anvil into wedging locking engagement with the closure tube3060when the closure tube3060has been moved into its distal-most position wherein the distal end of the closure tube3060is in contact with an anvil ledge3013formed on the anvil assembly3010. In one form, the anvil pulling assembly3090includes a pair of anvil pull cables3092that are attached to the proximal end of the anvil assembly3010and protrude proximally through the elongate shaft assembly to the tool mounting portion or handle assembly, whichever the case may be. The pull cables3092may be attached to an actuator mechanism on the handle assembly or be coupled to one of the drive systems on the tool mounting portion that is configured to apply tension to the cables3092. Operation of the end effector3000will now be described.FIGS.168and169illustrate the anvil assembly3010in an open position.FIG.168illustrates the firing member3100in proximal-most position wherein a new staple cartridge (not shown) may be mounted in the elongate channel3030. The closure tube3060is also in its proximal-most unactuated position. Also, as can be seen inFIG.167, when the firing member3100is in its proximal-most position, the actuation bar3102has biased the lock bar into engagement with the solenoid contact3076which enables the solenoid to be activated for the next closure sequence. Thus, to commence the closure process, the rotary drive shaft752is actuated to move the firing member3100to its starting position illustrated inFIG.169. When in that position, the actuation bar3102has moved in the proximal direction sufficiently to enable the lock bar3082to move out of engagement with the solenoid contact3076such that when power is supplied to the solenoid control circuit, the solenoid link3072is extended. Control power is then applied—either automatically or through a switch or other control mechanism in the handle assembly to the solenoid3070which moves the closure tube3060distally until the distal end of the closure tube3060contacts the ledge3013on the anvil assembly3010to cause the anvil assembly to pivot closed on the firing member1200″ as shown inFIG.162. As can be seen in that Figure, the lock bar3082is positioned to prevent movement of the closure tube3060in the proximal direction. When in that position, the clinician then applies tension to the pull cables3092to pull the proximal end of the anvil assembly3010into wedging engagement with the closure tube3060to lock the anvil assembly3010in the closed position. Thereafter, the firing member1200″ may be driven in the distal direction through the tissue clamped in the end effector3000. Once the firing process has been completed. The implement drive shaft is rotated in an opposite direction to return the firing member3100to its starting position wherein the actuation bar3102has once again contacted the lock bar3082to flex it into contact with the solenoid contact3076and to pull the ends of the lock bar3082into the windows3036in the elongate channel3030. When in that position, when power is supplied to the solenoid control system, the solenoid3070retracts the closure tube3060in the proximal direction to its starting or open position shown inFIGS.167and168. As the closure tube3060moves proximally out of engagement with the anvil assembly3010, the anvil spring3050applies a biasing force to the anvil trunnions3012to bias the anvil assembly to the open position shown inFIG.168. FIGS.171-178illustrate another exemplary elongate shaft assembly3200that has another exemplary quick disconnect coupler arrangement3210therein. In at least one form, for example, the quick disconnect coupler arrangement3210includes a proximal coupler member3212in the form of a proximal outer tube segment3214that, in one arrangement, may have a tube gear segment354thereon that is configured to interface with the first drive system350in the above-described manner when the device is to be robotically controlled. In another embodiment, however, the proximal outer tube segment3214may interface with a manually-actuatable rotation nozzle2512mounted to a handle assembly in the above-described manner. As discussed above, the first drive system350in a robotically-controlled application or the rotation nozzle2512in a handheld arrangement serve to rotate the elongate shaft assembly3200and the end effector operably coupled thereto about the longitudinal tool axis “LT-LT”. SeeFIG.171. The proximal outer tube segment3214has a “necked-down” distal end portion3216that is configured to receive a locking collar thereon. In the exemplary embodiment depicted inFIGS.171-178, the elongate shaft assembly3200includes a proximal drive shaft segment380″ that may be substantially identical to the proximal drive shaft segment380described above except for the differences discussed below and be configured to receive rotary and axial control motions from the robotic system or handle assembly in the various manners disclosed herein. The illustrated embodiment may be used with an articulation joint700as described above and include articulation cables434and454that may be coupled to the articulation control drives in the various manners described herein. A proximal filler material3220is provided within the proximal outer tube segment3214to provide axial support for the articulation cable end portions434A,434B,454A,454B. Each articulation cable end portion434A,434B,454A,454B extends through a corresponding proximal articulation passage3222provided through the proximal filler material3220. Each articulation cable end portion434A,434B,454A,454B further has a proximal articulation clip3224attached thereto that is configured to slide within the corresponding articulation passage3222. The proximal articulation clips3224may be fabricated from metal or polymer material and each have a pair of flexible clip arms3226that each have a fastener cleat3228formed thereon. Likewise, the proximal drive shaft segment380″ is movable received in a shaft passage3230in the proximal filler material3220. A drive shaft connection clip3240thereon. In one exemplary form, the drive shaft connection clip3240is formed with a central tubular connector portion3242and two flexible clip arms3244thereon that each have a fastener cleat3248thereon. As can be further seen inFIGS.171,172and176-178, the quick disconnect arrangement3210further includes a distal coupler member3250in the form of a distal outer tube segment3252that is substantially similar to the distal outer tube portion231described above except that the distal outer tube segment3252includes a necked down proximal end portion3254. The distal outer tube segment3252is operably coupled to an end effector1000of the various types disclosed herein and includes a distal drive shaft segment540″ that may be substantially similar to distal drive shaft segment540described above except for the differences noted below. A distal filler material3260is provided within the distal outer tube segment3252to provide axial support for the distal articulation cable segments444,445,446,447. Each distal articulation cable segment444,445,446,447extends through a corresponding distal articulation passage3262provided through the distal filler material3260. Each distal articulation cable segment444,445,446,447further has a distal articulation bayonet post3270attached thereto that is configured to slide between the clip arms3226of the corresponding proximal articulation clip3224. Each distal articulation bayonet post3270is configured to be retainingly engaged by the fastener cleats3228on the corresponding clip arms3226. Likewise, the distal drive shaft segment540″ is movably received in a distal shaft passage3264in the distal filler material3260. A distal drive shaft bayonet post3280is attached to the proximal end of the distal drive shaft segment540″ such that it may protrude proximally beyond the distal articulation bayonet posts3270.FIG.172illustrates the position of the distal drive shaft bayonet post3280(in broken lines) relative to the distal articulation bayonet posts3270. The distal drive shaft bayonet post3280is configured to be retainingly engaged by the fastener cleats3248on the corresponding clip arms3244on the drive shaft connection clip3240. As can be seen inFIGS.171-178, the exemplary quick disconnect coupler arrangement3210further includes an axially movable lock collar3290that is movably journaled on the necked down proximal end portion3254of the distal outer tube segment3252. As can be most particularly seen inFIG.174, one form of the lock collar3290includes an outer lock sleeve3292that is sized to be slidably received on the necked down portions3216,3254of the proximal outer tube segment3214and distal outer tube segment3254, respectively. The outer lock sleeve3292is coupled to central lock body3294by a bridge3295. The bridge3295is configured to slide through a distal slot3255in the necked down portion3254of the distal outer tube segment3254as well as a proximal slot3217in the necked down portion3216of the proximal outer tube segment3214that is slidably received within the necked down proximal end portion3254of the distal outer tube segment3252and may also slidably extend into the necked down portion3216of the proximal outer tube segment3214. As can be further seen inFIG.174, the central lock body3294has a plurality of passages3296for receiving the articulation posts and clips therethrough. Likewise, the central lock body3294has a central drive shaft passage3298for movably receiving the distal drive shaft segment540″ therein. Use of the exemplary quick disconnect coupler arrangement3210will now be described. Referring first toFIGS.171and172, the distal coupler member3250is axially aligned with the proximal coupler member3212such that the bridge3295is aligned with the slot3217in the necked down portion3216of the proximal outer tube segment3214and the distal drive shaft bayonet post3280is aligned with the central tubular connector portion3242on the proximal drive shaft connector clip3240. Thereafter, the distal coupler member3250is brought into abutting engagement with the proximal coupler member3212to cause the distal drive shaft bayonet post3280to slide into the central tubular segment3214an ultimately into retaining engagement with the fastener cleats3248on the proximal drive shaft connector clip3240. Such action also causes each distal articulation bayonet connector post3270to be retainingly engaged by the fastener cleats3228on the proximal articulation connector clips3224as shown inFIG.176. It will be appreciated that as the distal drive shaft bayonet post3280is inserted between the clip arms3244, the clip arms3244flex outward until the fastener cleats3248engage a shoulder3281on the post3280. Likewise, as each of the distal articulation bayonet posts3270are inserted between their corresponding connector arms3226, the connector arms3226flex outward until the fastener cleats3228engage a shoulder3271on the post3270. Once the distal drive shaft segment540″ has been connected to the proximal drive shaft segment380″ and the distal articulation cable segments444,445,446,447have been connected to the articulation cable end portions434A,434B,454A,454B, respectively, the user may then slide the outer lock sleeve3292proximally to the position shown inFIGS.177and178. When in that position, the central lock body3294prevents the clip arms3244,3226from flexing outward to thereby lock the distal coupler member3250to the proximal coupler member3212. To disconnect the distal coupler member3250from the proximal coupler member3212, the user moves the outer lock sleeve392to the position shown inFIGS.175and176and thereafter pulls the coupler members3250,3212apart. As opposing axial separation motions are applied to the coupler members3250,3212, the clip arms3244and3226are permitted to flex out of engagement with the distal drive shaft bayonet post and the distal articulation bayonet posts, respectively. NON-LIMITING EXAMPLES One exemplary form comprises a surgical tool for use with a robotic system that includes a tool drive assembly that is operatively coupled to a control unit of the robotic system that is operable by inputs from an operator and is configured to robotically-generate output motions. In at least one exemplary form, the surgical tool includes a drive system that is configured to interface with a corresponding portion of the tool drive assembly of the robotic system for receiving the robotically-generated output motions therefrom. A drive shaft assembly operably interfaces with the drive system and is configured to receive the robotically-generated output motions from the drive system and apply control motions to a surgical end effector that operably interfaces with the drive shaft assembly. A manually-actuatable control system operably interfaces with the drive shaft assembly to selectively apply manually-generated control motions to the drive shaft assembly. In connection with another general exemplary form, there is provided a surgical tool for use with a robotic system that includes a tool drive assembly that is operatively coupled to a control unit of the robotic system that is operable by inputs from an operator and is configured to provide at least one rotary output motion to at least one rotatable body portion supported on the tool drive assembly. In at least one exemplary form, the surgical tool includes a surgical end effector that comprises at least one component portion that is selectively movable between first and second positions relative to at least one other component portion thereof in response to control motions applied thereto. An elongate shaft assembly is operably coupled to the surgical end effector and comprises at least one gear-driven portion that is in operable communication with the at least one selectively movable component portion. A tool mounting portion is operably coupled to the elongate shaft assembly and is configured to operably interface with the tool drive assembly when coupled thereto. At least one exemplary form further comprises a tool mounting portion that comprises a driven element that is rotatably supported on the tool mounting portion and is configured for driving engagement with a corresponding one of the at least one rotatable body portions of the tool drive assembly to receive corresponding rotary output motions therefrom. A drive system is in operable engagement with the driven element to apply robotically-generated actuation motions thereto to cause the corresponding one of the at least one gear driven portions to apply at least one control motion to the selectively movable component. A manually-actuatable reversing system operably interfaces with the elongate shaft assembly to selectively apply manually-generated control motions thereto. In accordance with another exemplary general form, there is provided a surgical tool for use with a robotic system that includes a tool drive assembly that is operatively coupled to a control unit of the robotic system that is operable by inputs from an operator and is configured to robotically-generate rotary output motions. In at least one exemplary form, the surgical tool comprises a rotary drive system that is configured to interface with a corresponding portion of the tool drive assembly of the robotic system for receiving the robotically-generated rotary output motions therefrom. A rotary drive shaft assembly operably interfaces with the rotary drive system and is configured to receive the robotically-generated rotary output motions from the rotary drive system and apply rotary drive motions to a surgical end effector operably that interfaces with the rotary drive shaft assembly. A manually-actuatable reversing system operably interfaces with the rotary drive shaft assembly to selectively apply manually-generated rotary drive motions to the rotary drive shaft assembly. Another exemplary form comprises a surgical stapling device that includes an elongate shaft assembly that has a distal end and defines a longitudinal tool axis. The device further includes an end effector that comprises an elongate channel assembly that includes a portion that is configured to operably support a surgical staple cartridge therein. An anvil is movably supported relative to the elongate channel assembly. The surgical stapling device further comprises a rotary joint that couples the elongate channel assembly to the distal end of the elongate shaft assembly to facilitate selective rotation of the elongate channel assembly about the longitudinal tool axis relative to the distal end of the elongate shaft assembly. Another exemplary form comprises a rotary support joint assembly for coupling a first portion of a surgical instrument to a second portion of a surgical instrument. In at least one exemplary form, the rotary support joint assembly comprises a first annular race in the first portion and a second annular race in the second portion and which is configured for substantial registration with the first annular race when the second portion is joined with the first portion. A ring-like bearing is supported within the registered first and second annular races. In connection with another exemplary general form, there is provided a rotary support joint assembly for coupling a surgical end effector to an elongate shaft assembly of a surgical instrument. In at least one exemplary form, the rotary support joint assembly comprises a cylindrically-shaped connector portion on the surgical end effector. A first annular race is provided in the perimeter of the connector portion. A socket is provided on the elongate shaft and is sized to receive the cylindrically-shaped connector portion therein such that the cylindrically-shaped connector portion may freely rotate relative to the socket. A second annular race is provided in an inner wall of the socket and is configured for substantial registration with the first annular race when the cylindrically-shaped connector portion is received within the socket. A window is provided in the socket in communication with the second annular race. A ring-like bearing member that has a free end is insertable through the window into the first and second registered annular races. In connection with another exemplary general form, there is provided a method for rotatably coupling a first portion of a surgical instrument to a second portion of a surgical instrument. In various exemplary forms, the method comprises forming a first annular race in the first portion and forming a second annular race in the second portion. The method further includes inserting the first portion into the second portion such that the first and second annular races are in substantial registration and inserting a ring-like bearing within the registered first and second annular races. Another exemplary form comprises a drive shaft assembly for a surgical instrument that includes a plurality of movably interlocking joint segments that are interconnected to form a flexible hollow tube. A flexible secondary constraining member is installed in flexible constraining engagement with the plurality of movably interlocking joint segments to retain the interlocking joint segments in movable interlocking engagement while facilitating flexing of the drive shaft assembly. In accordance with another general exemplary form, there is provided a composite drive shaft assembly for a surgical instrument that includes a plurality of movably interlocking joint segments that are cut into a hollow tube by a laser and which has a distal end and a proximal end. A flexible secondary constraining member is in flexible constraining engagement with the plurality of movably interlocking joint segments to retain the interlocking joint segments in movable interlocking engagement while facilitating flexing of the drive shaft assembly. In accordance with yet another exemplary general form, there is provided a drive shaft assembly for a surgical instrument that includes a plurality of movably interconnected joint segments wherein at least some joint segments comprise a ball connector portion that is formed from six substantially arcuate surfaces. A socket portion is sized to movably receive the ball connector portion of an adjoining joint segment therein. A hollow passage extends through each ball connector portion to form a passageway through the drive shaft assembly. The drive shaft assembly may further include a flexible secondary constraining member installed in flexible constraining engagement with the plurality of movably interconnected joint segments to retain the joint segments in movable interconnected engagement while facilitating flexing of the drive shaft assembly. Another exemplary form comprises a method of forming a flexible drive shaft assembly for a surgical instrument. In various exemplary embodiments, the method comprises providing a hollow shaft and cutting a plurality of movably interconnected joint segments into the hollow shaft with a laser. The method further comprises installing a secondary constraining member on the hollow shaft to retain the movably interconnected joint segments in movable interconnected engagement while facilitating flexing of the drive shaft assembly. In connection with another exemplary form, there is provided a method of forming a flexible drive shaft assembly for a surgical instrument. In at least one exemplary embodiment, the method comprises providing a hollow shaft and cutting a plurality of movably interconnected joint segments into the hollow shaft with a laser. Each joint segment comprises a pair of opposing lugs wherein each lug has a tapered outer perimeter portion that is received within a corresponding socket that has a tapered inner wall portion which cooperates with the tapered outer perimeter portion of the corresponding lug to movably retain the corresponding lug therein. Another exemplary general form comprises a rotary drive arrangement for a surgical instrument that has a surgical end effector operably coupled thereto. In one exemplary form, the rotary drive arrangement includes a rotary drive system that is configured to generate rotary drive motions. A drive shaft assembly operably interfaces with the rotary drive system and is selectively axially movable between a first position and a second position. A rotary transmission operably interfaces with the drive shaft assembly and the surgical end effector such that when the drive shaft assembly is in the first axial position, application of one of the rotary drive motions to the drive shaft assembly by the rotary drive system causes the rotary transmission to apply a first rotary control motion to the surgical end effector and when the drive shaft assembly is in the second axial position, application of the rotary drive motion to the drive shaft assembly by the rotary drive system causes the rotary transmission to apply a second rotary control motion to the surgical end effector. In connection with another exemplary general form, there is provided a surgical tool for use with a robotic system that includes a tool drive assembly that is operatively coupled to a control unit of the robotic system that is operable by inputs from an operator and is configured to generate output motions. In at least one exemplary form the surgical tool comprises a tool mounting portion that is configured operably interface with a portion of the robotic system. A rotary drive system is operably supported by the tool mounting portion and interfaces with the tool drive assembly to receive corresponding output motions therefrom. An elongate shaft assembly operably extends from the tool mounting portion and includes a drive shaft assembly that operably interfaces with the rotary drive system. The drive shaft assembly is selectively axially movable between a first position and a second position. The surgical tool further comprises a surgical end effector that is rotatably coupled to the elongate shaft assembly for selective rotation relative thereto. A rotary transmission operably interfaces with the drive shaft assembly and the surgical end effector such that when the drive shaft assembly is in the first axial position, application of one of the rotary drive motions to the drive shaft assembly by the rotary drive system causes the rotary transmission to apply a first rotary control motion to the surgical end effector and when the drive shaft assembly is in the second axial position, application of the rotary drive motion to the drive shaft assembly by the rotary drive system causes the rotary transmission to apply a second rotary control motion to the surgical end effector. In connection with yet another exemplary general form, there is provided a surgical instrument that comprises a handle assembly and a drive motor that is operably supported by the handle assembly. An elongate shaft assembly operably extends from the handle assembly and includes a drive shaft assembly that operably interfaces with the drive motor and is selectively axially movable between a first position and a second position. A surgical end effector is rotatably coupled to the elongate shaft assembly for selective rotation relative thereto. A rotary transmission operably interfaces with the drive shaft assembly and the surgical end effector such that when the drive shaft assembly is in the first axial position, application of a rotary drive motion to the drive shaft assembly by the drive motor causes the rotary transmission to apply a first rotary control motion to the surgical end effector and when the drive shaft assembly is in the second axial position, application of the rotary drive motion to the drive shaft assembly by the drive motor causes the rotary transmission to apply a second rotary control motion to the surgical end effector. Various exemplary embodiments also comprise a differential locking system for a surgical instrument that includes a surgical end effector that is powered by a rotary drive shaft assembly that is movable between a plurality of discrete axial positions. In at least one form, the differential locking system comprises at least one retention formation on the rotary drive shaft assembly that corresponds to each one of the discrete axial positions. At least one lock member is operably supported relative to rotary drive shaft assembly for retaining engagement with the at least one retention formation when the rotary drive shaft assembly is moved to the discrete axial positions associated therewith. In connection with another exemplary general form, there is provided a differential locking system for a surgical instrument that includes a surgical end effector powered by a rotary drive shaft assembly that is movable between a first axial position and a second axial position. In at least one exemplary form, the differential locking system comprises a differential housing that operably interfaces with the rotary drive shaft assembly and the surgical end effector. At least one spring-biased lock member operably supported by the differential housing for retaining engagement with a first portion of the rotary drive shaft assembly when the rotary drive shaft assembly is in the first axial position and the at least one spring-biased lock member further configured to retainingly engage a second portion of the rotary drive shaft assembly when the rotary drive shaft assembly is in the second axial position. In connection with yet another exemplary general form, there is provided a differential locking system for a surgical instrument that includes a surgical end effector that is powered by a rotary drive shaft assembly that is movable between a first axial position and a second axial position. In at least one exemplary form, the differential locking system comprises a differential housing that operably interfaces with the rotary drive shaft assembly and the surgical end effector. At least one spring member is provided on a portion of the rotary drive shaft assembly wherein each spring member defines a first retaining position that corresponds to the first axial position of the rotary drive shaft assembly and a second retaining position that corresponds to the second axial position of the rotary drive shaft assembly. A lock member is operably supported by the differential housing and corresponds to each of the at least one spring members for retaining engagement therewith such that the lock member retainingly engages the corresponding spring member in the first retaining position when the rotary drive shaft assembly is in the first axial position and the lock member retainingly engages the corresponding spring member in the second retaining position when the rotary drive shaft assembly is in the second axial position. Various other exemplary embodiments comprise a surgical instrument that includes an end effector and a proximal rotary drive train assembly that is operably coupled to a source of rotary and axial control motions. The proximal rotary drive train assembly is longitudinally shiftable in response to applications of the axial control motions thereto. The surgical instrument further includes a distal rotary drive train assembly that is operably coupled to the end effector to apply the rotary control motions thereto. A proximal axial drive train assembly is operably coupled to another source of axial control motions. A distal axial drive train assembly is operably coupled to the end effector to apply the axial control motions thereto. The instrument further comprises a coupling arrangement for simultaneously attaching and detaching the proximal rotary drive train assembly to the distal rotary drive train assembly and the proximal axial drive train assembly to the distal axial drive train assembly. In connection with another general aspect, there is provided a coupling arrangement for attaching an end effector including a plurality of distal drive train assemblies that are configured to apply a plurality of control motions to the end effector to corresponding proximal drive train assemblies communicating with a source of drive motions. In one exemplary form, the coupling arrangement comprises a proximal attachment formation on a distal end of each proximal drive train assembly and a proximal coupler member that is configured to operably support each proximal drive train assembly therein such that the proximal attachment formations thereon are retained in substantial coupling alignment. A distal attachment formation is provided on a proximal end of each distal drive train assembly. Each distal attachment formation is configured to operably engage a proximal attachment formation on the distal end of a corresponding proximal drive train when brought into coupling engagement therewith. A distal coupler member is operably coupled to the end effector and is configured to operably support each distal drive train therein to retain the distal attachment formations thereon in substantial coupling alignment. A locking collar is movable from an unlocked position wherein the distal drive train assemblies may be decoupled from the corresponding proximal drive train assemblies and a locked position wherein the distal drive train assemblies are retained in coupled engagement with their corresponding proximal drive train assemblies. In connection with another general aspect, there is provided a surgical instrument that includes an end effector that is configured to perform surgical activities in response to drive motions applied thereto. An exemplary form of the instrument further includes a source of drive motions and a first proximal drive train assembly that operably interfaces with the source of drive motions for receiving corresponding first drive motions therefrom. A second proximal drive train assembly operably interfaces with the source of drive motions for receiving corresponding second drive motions therefrom. A first distal drive train assembly operably interfaces with the end effector and is configured to receive the corresponding first drive motions from the first proximal drive train assembly when it is operably coupled thereto. A second distal drive train assembly operably interfaces with the end effector and is configured to receive the corresponding second drive motions from the second proximal drive train assembly when it is operably coupled thereto. The instrument further comprises a coupling arrangement that includes a first coupling member that operably supports the first and second proximal drive train assemblies therein. The coupling arrangement further includes a second coupling member that operably supports the first and second distal drive train assemblies therein and is configured for axial alignment with the first coupling member such that when the second coupling member is axially aligned with the first coupling member, the first distal drive train assembly is in axial alignment with the first proximal drive train assembly for operable engagement therewith and the second distal drive train assembly is in axial alignment with the second proximal drive train assembly for operable engagement therewith. A locking collar is movably journaled on one of the first and second coupling members and is configured to move between an unlocked position wherein the first and second distal drive train assemblies are detachable from the first and second proximal drive train assemblies, respectively and a locked position wherein the first and second distal drive train assemblies are retained in operable engagement with the first and second proximal drive train assemblies, respectively. In accordance with another general aspect, there is provided a surgical cartridge that includes a cartridge body that defines a path therethrough for operably receiving a firing member of a surgical instrument. The surgical cartridge further includes an alignment member that is operably supported in the cartridge body and is configured to move the firing member from an inoperable configuration wherein firing member is misaligned with the path to an operable configuration wherein the firing member is in alignment with the path when the firing member is driven into contact therewith. In accordance with yet another general aspect, there is provided an end effector for a surgical instrument. In at least one form, the end effector comprises a support member that has a slot and a lockout notch that is adjacent to the slot. The end effector further comprises a firing member that is movable between an inoperable configuration and an operable configuration, wherein the firing member is aligned with the slot and is structured to translate in the slot when it is in the operable configuration and wherein the firing member is engaged with the lockout notch and misaligned with the slot when it is in the inoperable configuration. Another exemplary embodiment comprises a surgical instrument that includes an elongate channel that is configured to removably support a cartridge therein. In at least one form, the cartridge comprises a cartridge body and an alignment member that is movably supported within the cartridge body for movement from a first position to a second position therein. The surgical instrument also comprises a firing member that is operably supported relative to the elongate channel for movement between a starting position and an ending position upon application of actuation motions thereto. The firing member is incapable from moving from the starting position to the ending position unless the firing member is in operable engagement with the alignment member in the cartridge body. Another exemplary embodiment comprises an end effector for a surgical instrument. In at least one form, the end effector comprises an elongate channel that is configured to removably support a cartridge therein. A firing member is operably supported relative to the elongate channel for movement between a starting and ending position. An implement drive shaft is in operable engagement with the firing member for moving the firing member between the starting and ending positions upon applications of actuation motions thereto from a drive arrangement. The implement drive shaft is moveable from an inoperable position wherein the implement drive shaft is out of operable engagement with the drive arrangement to an operable position wherein the implement drive shaft is in operable engagement with the drive arrangement. The end effector further comprises an alignment member that is movably supported for contact with the implement drive shaft to move the implement drive shaft from the inoperable position to the operable position upon installation of a cartridge in the elongate channel. Another exemplary embodiment includes a surgical instrument that comprises an elongate channel and a cartridge that is removably supported in the elongate channel. A firing member is operably supported relative to the elongate channel for movement between a starting and ending position. An implement drive shaft is in operable engagement with the firing member for moving the firing member between the starting and ending positions upon applications of actuation motions thereto from a drive arrangement. The implement drive shaft is moveable from an inoperable position wherein the implement drive shaft is out of operable engagement with the drive arrangement to an operable position wherein the implement drive shaft is in operable engagement with the drive arrangement. The surgical instrument further comprises an alignment member movably supported for contact with the implement drive shaft to move the implement drive shaft from the inoperable position to the operable position upon installation of a cartridge in the elongate channel. The devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. In either case, however, the device can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, the device can be disassembled, and any number of the particular pieces or parts of the device can be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, the device can be reassembled for subsequent use either at a reconditioning facility, or by a surgical team immediately prior to a surgical procedure. Those skilled in the art will appreciate that reconditioning of a device can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application. Although the present invention has been described herein in connection with certain disclosed exemplary embodiments, many modifications and variations to those exemplary embodiments may be implemented. For example, different types of end effectors may be employed. Also, where materials are disclosed for certain components, other materials may be used. The foregoing description and following claims are intended to cover all such modification and variations. Any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated materials does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.

11857190

The drawings are not intended to be limiting in any way, and it is contemplated that various embodiments of the invention may be carried out in a variety of other ways, including those not necessarily depicted in the drawings. The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention; it being understood, however, that this invention is not limited to the precise arrangements shown. DETAILED DESCRIPTION The following description of certain examples of the technology should not be used to limit its scope. Other examples, features, aspects, embodiments, and advantages of the technology will become apparent to those skilled in the art from the following description, which is by way of illustration, one of the best modes contemplated for carrying out the technology. As will be realized, the technology described herein is capable of other different and obvious aspects, all without departing from the technology. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not restrictive. It is further understood that any one or more of the teachings, expressions, embodiments, examples, etc. described herein may be combined with any one or more of the other teachings, expressions, embodiments, examples, etc. that are described herein. The following-described teachings, expressions, embodiments, examples, etc. should therefore not be viewed in isolation relative to each other. Various suitable ways in which the teachings herein may be combined will be readily apparent to those of ordinary skill in the art in view of the teachings herein. Such modifications and variations are intended to be included within the scope of the claims. For clarity of disclosure, the terms “proximal” and “distal” are defined herein relative to a human or robotic operator of the surgical instrument. The term “proximal” refers the position of an element closer to the human or robotic operator of the surgical instrument and further away from the surgical end effector of the surgical instrument. The term “distal” refers to the position of an element closer to the surgical end effector of the surgical instrument and further away from the human or robotic operator of the surgical instrument. In addition, the terms “upper,” “lower,” “lateral,” “transverse,” “bottom,” “top,” are relative terms to provide additional clarity to the figure descriptions provided below. The terms “upper,” “lower,” “lateral,” “transverse,” “bottom,” “top,” are thus not intended to unnecessarily limit the invention described herein. I. Exemplary Surgical Stapler FIGS.1-7depict an exemplary surgical stapling and severing instrument (10) that is sized for insertion through a trocar cannula or an incision (e.g., thoracotomy, etc.) to a surgical site in a patient for performing a surgical procedure. Instrument (10) of the present example includes a handle portion (20) connected to a shaft (22), which distally terminates in an articulation joint (11), which is further coupled with an end effector (12). Once articulation joint (11) and end effector (12) are inserted through the cannula passageway of a trocar, articulation joint (11) may be remotely articulated, as depicted in phantom inFIG.1, by an articulation control (13), such that end effector (12) may be deflected from the longitudinal axis (LA) of shaft (22) at a desired angle (a). End effector (12) of the present example includes a lower jaw (16) that includes a staple cartridge (37), and an upper jaw in the form of a pivotable anvil (18). Handle portion (20) includes a pistol grip (24) and a closure trigger (26). Closure trigger (26) is pivotable toward pistol grip (24) to cause clamping, or closing, of the anvil (18) toward lower jaw (16) of end effector (12). Such closing of anvil (18) is provided through a closure tube (32) and a closure ring (33), which both longitudinally translate relative to handle portion (20) in response to pivoting of closure trigger (26) relative to pistol grip (24). Closure tube (32) extends along the length of shaft (22); and closure ring (33) is positioned distal to articulation joint (11). Articulation joint (11) is operable to communicate/transmit longitudinal movement from closure tube (32) to closure ring (33). As shown inFIG.2, handle portion (20) also includes a firing trigger (28). An elongate member (not shown) longitudinally extends through shaft (22) and communicates a longitudinal firing motion from handle portion (20) to a firing beam (14) in response to actuation of firing trigger (28). This distal translation of firing beam (14) causes the stapling and severing of clamped tissue in end effector (12), as will be described in greater detail below. As shown inFIGS.3-6, end effector (12) employs a firing beam (14) that includes a transversely oriented upper pin (38), a firing beam cap (44), a transversely oriented middle pin (46), and a distally presented cutting edge (48). Upper pin (38) is positioned and translatable within a longitudinal anvil slot (42) of anvil (18). Firing beam cap (44) slidably engages a lower surface of lower jaw (16) by having firing beam (14) extend through lower jaw slot (45) (shown inFIG.4B) that is formed through lower jaw (16). Middle pin (46) slidingly engages a top surface of lower jaw (16), cooperating with firing beam cap (44). FIG.3shows firing beam (14) of the present example proximally positioned and anvil (18) pivoted to an open configuration, allowing an unspent staple cartridge (37) to be removably installed into a channel of lower jaw (16). As best seen inFIGS.5-6, staple cartridge (37) of the present example includes a cartridge body (70), which presents an upper deck (72) and is coupled with a lower cartridge tray (74). As best seen inFIG.3, a vertical slot (49) extends longitudinally through a portion of staple cartridge body (70). As also best seen inFIG.3, three rows of staple apertures (51) are formed through upper deck (72) on each lateral side of vertical slot (49). As shown inFIGS.4A-6, a wedge sled (41) and a plurality of staple drivers (43) are captured between cartridge body (70) and tray (74), with wedge sled (41) being located proximal to staple drivers (43). Wedge sled (41) is movable longitudinally within staple cartridge (37); while staple drivers (43) are movable vertically within staple cartridge (37). Staples (47) are also positioned within cartridge body (70), above corresponding staple drivers (43). Each staple (47) is driven vertically within cartridge body (70) by a staple driver (43) to drive staple (47) out through an associated staple aperture (51). As best seen inFIGS.4A-4B and6, wedge sled (41) presents inclined cam surfaces that urge staple drivers (43) upwardly as wedge sled (41) is driven distally through staple cartridge (37). With end effector (12) closed, as depicted inFIGS.4A-4Bby distally advancing closure tube (32) and closure ring (33), firing beam (14) is then advanced distally into engagement with anvil (18) by having upper pin (38) enter longitudinal anvil slot (42). A pusher block (80) (shown inFIG.5) located at the distal end of firing beam (14) pushes wedge sled (41) distally as firing beam (14) is advanced distally through staple cartridge (37) when firing trigger (28) is actuated. During such firing, cutting edge (48) of firing beam (14) enters vertical slot (49) of staple cartridge (37), severing tissue clamped between staple cartridge (37) and anvil (18). As shown inFIGS.4A-4B, middle pin (46) and pusher block (80) together actuate staple cartridge (37) by entering into vertical slot (49) within staple cartridge (37), driving wedge sled (41) into upward camming contact with staple drivers (43), which in turn drives staples (47) out through staple apertures (51) and into forming contact with staple forming pockets (53) (shown inFIG.3) on the inner surface of anvil (18).FIG.4Bdepicts firing beam (14) fully distally translated after completing severing and stapling of tissue. Staple forming pockets (53) are intentionally omitted from the view inFIGS.4A-4Bbut are shown inFIG.3. Anvil (18) is intentionally omitted from the view inFIG.5. FIG.7shows end effector (12) having been actuated through a single firing stroke through tissue (90). Cutting edge (48) (obscured inFIG.7) has cut through tissue (90), while staple drivers (43) have driven three alternating rows of staples (47) through the tissue (90) on each side of the cut line produced by cutting edge (48). After the first firing stroke is complete, end effector (12) is withdrawn from the patient, spent staple cartridge (37) is replaced with a new staple cartridge (37), and end effector (12) is then again inserted into the patient to reach the stapling site for further cutting and stapling. This process may be repeated until the desired quantity and pattern of firing strokes across the tissue (90) has been completed. Instrument (10) may be further constructed and operable in accordance with any of the teachings of the following references, the disclosures of which are incorporated by reference herein: U.S. Pat. No. 8,210,411, entitled “Motor-Driven Surgical Instrument,” issued Jul. 3, 2012; U.S. Pat. No. 9,186,142, entitled “Surgical Instrument End Effector Articulation Drive with Pinion and Opposing Racks,” issued on Nov. 17, 2015; U.S. Pat. No. 9,517,065, entitled “Integrated Tissue Positioning and Jaw Alignment Features for Surgical Stapler,” issued Dec. 13, 2016; U.S. Pat. No. 9,622,746, entitled “Distal Tip Features for End Effector of Surgical Instrument,” issued Apr. 18, 2017; U.S. Pat. No. 9,717,497, entitled “Lockout Feature for Movable Cutting Member of Surgical Instrument,” issued Aug. 1, 2017; U.S. Pat. No. 9,795,379, entitled “Surgical Instrument with Multi-Diameter Shaft,” issued Oct. 24, 2017; U.S. Pat. No. 9,808,248, entitled “Installation Features for Surgical Instrument End Effector Cartridge,” issued Nov. 7, 2017; U.S. Pat. No. 9,839,421, entitled “Jaw Closure Feature for End Effector of Surgical Instrument,” issued Dec. 12, 2017; and/or U.S. Pat. No. 10,092,292, entitled “Staple Forming Features for Surgical Stapling Instrument,” issued Oct. 9, 2018. II. Exemplary Buttress Assembly and Buttress Applier Cartridge In some instances, it may be desirable to equip end effector (12) of surgical instrument (10) with an adjunct material, such as a buttress, to reinforce the mechanical fastening of tissue provided by staples (47). Such a buttress may prevent the applied staples (47) from pulling through the tissue and may otherwise reduce a risk of tissue tearing at or near the site of applied staples (47). In addition to or as an alternative to providing structural support and integrity to a line of staples (47), a buttress may provide various other kinds of effects such as spacing or gap-filling, administration of therapeutic agents, and/or other effects. In some instances, a buttress may be provided on upper deck (72) of staple cartridge (37). As described above, deck (72) houses staples (47), which are driven by staple driver (43). In some other instances, a buttress may be provided on the surface of anvil (18) that faces staple cartridge (37). It should also be understood that a first buttress may be provided on upper deck (72) of staple cartridge (37) while a second buttress is provided on anvil (18) of the same end effector (12). Various examples of forms that a buttress may take will be described in greater detail below. Various ways in which a buttress may be secured to a staple cartridge (37) or an anvil (18) will also be described in greater detail below. Exemplary buttress assemblies, exemplary materials and techniques for applying buttress assemblies, and exemplary buttress applier cartridges may be configured in accordance with at least some of the teachings of U.S. Pat. No. 10,166,023, entitled “Method of Applying a Buttress to a Surgical Stapler End Effector,” issued Jan. 1, 2019; and/or in U.S. Pat. No. 10,349,939, entitled “Method of Applying a Buttress to a Surgical Stapler,” issued Jul. 16, 2019, the disclosures of which are incorporated by reference herein. A. Exemplary Composition of Buttress Assembly FIG.8shows an exemplary pair of buttress assemblies (110,112) (each also referred to individually as a “buttress”). Buttress assembly (110) of this example comprises a buttress body (114) and an upper adhesive layer (116). Similarly, buttress assembly (112) comprises a buttress body (118) and a lower adhesive layer (120). In the present example, each buttress body (114,118) comprises a strong yet flexible material configured to structurally support a line of staples (47). By way of example only, each buttress body (114,118) may comprise a mesh of polyglactin910material by Ethicon, Inc. of Somerville, N.J. Alternatively, any other suitable materials or combinations of materials may be used in addition to or as an alternative to polyglactin910material to form each buttress body (114,118). Each buttress body (114,118) may comprise a material including, for example, a hemostatic agent such as fibrin to assist in coagulating blood and reduce bleeding at the severed and/or stapled surgical site along tissue (T1, T2). As another merely illustrative example, each buttress body (114,118) may comprise other adjuncts or hemostatic agents such as thrombin may be used such that each buttress body (114,118) may assist to coagulate blood and reduce the amount of bleeding at the surgical site. Other adjuncts or reagents that may be incorporated into each buttress body (114,118) may further include but are not limited to medical fluid or matrix components. In the present example, adhesive layer (116) is provided on buttress body (114) to adhere buttress body (114) to underside (124) of anvil (18). Similarly, adhesive layer (120) is provided on buttress body (118) to adhere buttress body (118) to upper deck (72) of staple cartridge (37). Such an adhesive material may provide proper positioning of buttress body (114,118) before and during actuation of end effector (12); then allow buttress body (114,118) to separate from end effector (12) after end effector (12) has been actuated, without causing damage to buttress body (114,118) that is substantial enough to compromise the proper subsequent functioning of buttress body (114,118). B. Exemplary Stapling of Tissue with Buttress Assemblies FIGS.9A-9Cshow an exemplary sequence in which surgical stapler end effector (12), which has been loaded with buttress assemblies (110,112), is actuated to drive staples (47) through two opposed layers of tissue (T1, T2), with buttress assemblies (110,112) being secured to the same layers of tissue (T1, T2) by staples (47). In particular,FIG.9Ashows layers of tissue (T1, T2) positioned between anvil (18) and staple cartridge (37), with anvil (18) in the open position. Buttress assembly (110) is adhered to underside (124) of anvil (18) via adhesive layer (116); while buttress assembly (112) is adhered to upper deck (72) of staple cartridge (37) via adhesive layer (120). Layers of tissue (T1, T2) are thus interposed between buttress assemblies (110,112). Next, closure trigger (26) is pivoted toward pistol grip (24) to drive closure tube (32) and closure ring (33) distally. This drives anvil (18) to the closed position as shown inFIG.9B. At this stage, layers of tissue (T1, T2) are compressed between anvil (18) and staple cartridge (37), with buttress assemblies (110,112) engaging opposite surfaces of tissue layers (T1, T2). End effector (12) is then actuated as described above, driving staple (47) through buttress assemblies (110,112) and tissue (T1, T2). As shown inFIG.13C, crown (122) of driven staple (47) captures and retains buttress assembly (112) against layer of tissue (T2). Deformed legs (126) of staple (47) capture and retain buttress assembly (110) against layer of tissue (T1). A series of staples (47) similarly capture and retain buttress assemblies (110,112) against layers of tissue (T1, T2), thereby securing buttress assemblies (110,112) to tissue (T1, T2) as shown inFIG.10. As end effector (12) is pulled away from tissue (T1, T2) after deploying staples (47) and buttress assemblies (110,112), buttress assemblies (110,112) disengage end effector such that buttress assemblies (110,112) remain secured to tissue (T1, T2) with staples (47). Buttresses (110,112) thus provides structural reinforcement to the lines of staples (47) formed in tissue (T1, T2). As can also be seen inFIG.10, distally presented cutting edge (48) of firing beam (14) also cuts through a centerline of buttress tissue assemblies (110,112), separating each buttress assembly (110,112) into a corresponding pair of sections, such that each section remains secured to a respective severed region of tissue (T1, T2). C. Exemplary Buttress Applier Cartridge with Active Retainer Arms Because end effector (12) of surgical instrument (10) may be actuated multiple times during a single surgical procedure, it may be desirable to enable an operator to repeatedly and easily load buttress assemblies (110,112) onto end effector jaws (16,18) during that single surgical procedure.FIGS.11-13Bshow an exemplary buttress applier cartridge (210) (also referred to as a “buttress applicator”) that may be used to support, protect, and apply adjunct material, such as buttress assemblies (110,112), to end effector (12). As best seen inFIGS.11-12, cartridge (210) of this example comprises an open end (212) and a closed end (214). Open end (212) is configured to receive end effector (12) as will be described in greater detail below. Cartridge (210) further includes a first housing (216a) and a second housing (216b), which each collectively generally define a “U” shape to present open end (212). A platform (218) and a sled retainer (220) are interposed between first and second housings (216a,216b). Platform (218) of the present example is configured to support a pair of buttress assemblies (110) on one side of platform (218) and another pair of buttress assemblies (112) on the other side of platform (218). Platform (218) is exposed in recesses that are formed between the prongs of the “U” configuration of first and second housings (216a,216b). Each buttress assembly (110,112) is provided in a respective pair of portions that are separated to avoid spanning across slots (42,49) of anvil (18) and staple cartridge (37), respectively, though platform (218) may just as easily support wide versions of buttress assemblies (110,112) that unitarily span across slots (42,49) of anvil (18) and staple cartridge (37), respectively. More specifically, the outer edges of platform (218) include retention features (230) in the form of ridges that further engage first and second housings (216a,216b) to prevent platform (218) from sliding relative to first and second housings (216a,216b). First and second housings (216a,216b) include integral gripping features (222) and indicator plates (224) positioned to correspond with windows (226) formed in first and second housings (216a,216b), such that indicator plates (224) are visible through windows (226) at different times. Arms (228) of the present example are configured to selectively secure buttress assemblies (110,112) to platform (218). In the present example, arms (228) are resilient and are thus configured to resiliently bear against buttress assemblies (110,112), thereby pinching buttress assemblies (110,112) against platform (218). Buttress applier cartridge (210) includes a pair of tapered cam surfaces (232) and a respective pair of housing engagement features (234) positioned to engage corresponding surfaces of first and second housings (216a,216b). First and second housings (216a,216b) include proximal guide features (236) and distal guide features (238) configured to assist in providing proper alignment of end effector (40) with cartridge (210). FIG.13Ashows cartridge (210) in a configuration where retainer arms (228) are positioned to hold buttress assemblies (110,112) against platform (218); whileFIG.13Bshows cartridge (210) in a configuration where retainer arms (228) are positioned to release buttress assemblies (110,112) from platform (218). WhileFIGS.13A-13Bonly show buttress assembly (110) on platform (218), buttress assembly (112) would be retained on and released from platform (218) in an identical fashion. To use cartridge (210) to load end effector (12), the operator would first position cartridge (210) and end effector (12) such that end effector is aligned with open end (212) of cartridge (210) as shown inFIG.13A. The operator would then advance end effector (12) distally, and/or advance cartridge (210) proximally, to position platform (218) and buttress assemblies (110,112) between anvil (18) and staple cartridge (37) as shown inFIG.13B. Closure trigger (26) of instrument (10) is then squeezed by the operator to close end effector jaws (16,18) on platform (218), thereby adhesively attaching buttress assemblies (110,112) to anvil (18) and staple cartridge (37), and simultaneously depressing cam surface (232). Depression of cam surface (232) actuates retainer arms (228) laterally outwardly to thereby release buttress assemblies (110,112) from platform (218), such that end effector jaws (16,18) may be disengaged from platform (218) while buttress assemblies (110,112) remain adhered to anvil (18) and staple cartridge (37). III. Exemplary Applicator Devices with Buttress Trimming Features In some instances, it may be desirable to vary the length of a staple reinforcing adjunct element, such as for modifying the adjunct element to be compatible with an end effector jaw that may be incompatible with an initial length of the adjunct element. For example, an adjunct element may have an initial length (e.g., approximately 60 mm) for use with a first end effector jaw having a first jaw length (e.g., approximately 60 mm). In some instances, it may be desirable to shorten such an adjunct element to a predetermined subsequent length (e.g., approximately 45 mm) such that the adjunct element may be compatible with a second end effector jaw having a second jaw length (e.g., approximately 45 mm). Thus, it may be desirable to provide an applicator device that is configured to facilitate adjustment of the length of the adjunct element from the initial length to the predetermined subsequent length prior to application of the adjunct element to the end effector jaw. Each of the exemplary applicator devices described below provide such functionality. It will be appreciated that any of the exemplary applicator devices described below may be configured to apply an adjunct element in the form of a buttress, such as buttresses (110,112) described above, or a tissue thickness compensator, for example of the type disclosed in U.S. Pat. Pub. No. 2012/0080336, entitled “Staple Cartridge Comprising Staples Positioned Within A Compressible Portion Thereof,” published Apr. 5, 2012 and now abandoned, the disclosure of which is incorporated by reference herein. Additionally, application of a staple reinforcement element to an end effector jaw may be achieved with adhesive features as described above and/or with mechanical coupling features, for example of the type disclosed in U.S. Pat. No. 7,665,646, entitled “Interlocking Buttress Material Retention System,” issued Feb. 23, 2010, the disclosure of which is incorporated by reference herein. Furthermore, any of the exemplary applicator devices described below may be suitably constructed for a single use or for multiple uses. A. Exemplary Buttress Applicator with Knife Grooves FIG.14shows an exemplary buttress applicator (310) for applying at least one buttress assembly (312) to at least one jaw of an end effector, such as at least one jaw (16,18) of end effector (12), and configured to facilitate adjustment of the length of buttress assembly (312). Buttress applicator (310) and buttress assembly (312) are similar to buttress applicator (210) and buttress assemblies (110,112) described above, respectively, except as otherwise described below. In this regard, buttress assembly (312) of this example comprises a buttress body (314) and at least one adhesive bead (316) for adhering buttress body (314) to underside (124) of anvil (18) or to upper deck (72) of staple cartridge (37). In some versions, buttress assembly (312) may have an initial length of approximately 60 mm. Buttress applicator (310) of this example comprises an open end (322) and a closed end (324). Open end (322) is configured to receive end effector (12) in a manner similar to that described above in connection withFIGS.13A-13B. Buttress applicator (310) further includes at least one housing (326) which generally defines a “U” shape to present open end (322). A platform (328) extends longitudinally between proximal and distal ends (329,330) and is exposed in one or more recesses (331) that are formed between the prongs of the “U” configuration of housing (326) and is configured to support buttress assembly (312) on an upper side of platform (328), though platform (328) may just as easily support another buttress assembly (312) on a lower side of platform (328). While buttress assembly (312) is illustrated as a relatively wide version that may unitarily span across slot (42) of anvil (18) or slot (49) of staple cartridge (37), buttress assembly (312) may be provided in a pair of portions that are separated to avoid spanning across either slot (42,49). In any event, housing (326) includes integral gripping features (332), and a plurality of arms (338) are configured to resiliently bear against buttress assembly (312), thereby pinching buttress assembly (312) against platform (328) to selectively secure buttress assembly (312) to platform (328). Housing (326) also includes proximal guide features (346) and distal guide features (348) configured to assist in providing proper alignment of end effector (40) with buttress applicator (310). Buttress applicator (310) of the present example further includes a buttress trimming feature in the form of a laterally-opposed pair of grooves (350) extending partially through housing (326) and configured to guide a blade of a cutting instrument, such as a knife or a scalpel (not shown), across buttress assembly (312) to thereby shorten buttress assembly (312) from the initial length to a predetermined subsequent length. More particularly, grooves (350) may guide such a blade to sever a scrap distal portion of buttress assembly (312) on the upper side of platform (328) from a desired proximal portion of buttress assembly (312) having the predetermined subsequent length. In this regard, grooves (350) each extend laterally outwardly from recess (331) and transversely downwardly from an upper surface of housing (326). In some versions, grooves (350) may each have a width in the longitudinal direction sufficient to slidably receive the blade. In addition, or alternatively, grooves (350) may each have a depth in the transverse direction relative to an upper surface of housing (326) generally equal to that of platform (328) such that a base surface of each groove (350) may be substantially flush with the upper surface of platform (328) to assist with maintaining the blade at a substantially constant height when guided across buttress assembly (312) by grooves (350). A cutting surface constructed of a material more durable than that of housing (326) may be embedded within housing (326) at or near the base surfaces of grooves (350) to inhibit the blade from scoring or otherwise cutting housing (326). For example, housing (326) may be constructed of silicone while such a cutting surface may be constructed of metal or any polymer having a greater durability than that of silicone. In some versions, such a cutting surface may extend across platform (328) to inhibit the blade from scoring or otherwise cutting platform (328). Grooves (350) of the present example collectively define a cutting line that is generally perpendicular to the longitudinal direction and that is positioned at a predetermined distance from proximal end (329) of platform (328) corresponding to the predetermined subsequent length. For example, grooves (350) may be positioned approximately 45 mm from proximal end (329) such that the blade may shorten buttress assembly (312) to a predetermined subsequent length of approximately 45 mm when guided across buttress assembly (312) by grooves (350). It will be appreciated that grooves (350) may be positioned at any other suitable distance from proximal end (329) and/or may be suitably positioned relative to any other reference portion of buttress applicator (310) for facilitating shortening of buttress assembly (312). While a single pair of grooves (350) is shown for facilitating shortening of buttress assembly (312) to a single predetermined subsequent length, multiple pairs of grooves (350) may be provided along the length of platform (328) for facilitating shortening of buttress assembly (312) to any number of predetermined subsequent lengths. In any event, arms (338) may continue to secure the scrap distal portion of buttress assembly (312) to platform (328) after the desired proximal portion of buttress assembly (312) has been severed and applied to a corresponding end effector jaw (16,18). While grooves (350) are shown positioned on an upper side of housing (326), grooves (350) may additionally or alternatively be positioned on a lower side of housing (326), such as for guiding a blade across another buttress assembly (312) on the lower side of platform (328). Also, while grooves (350) are shown incorporated into buttress applicator (310) having the configuration described above, it will be appreciated that grooves (350) may be readily incorporated into a buttress applicator having any other suitable configuration, such as that described below in connection withFIGS.18A-18C. B. Exemplary Buttress Applicator with Scissor Slots FIG.15shows another exemplary buttress applicator (410) for applying at least one buttress assembly (412) to at least one jaw of an end effector, such as at least one jaw (16,18) of end effector (12), and configured to facilitate adjustment of the length of buttress assembly (412). Buttress applicator (410) and buttress assembly (412) are similar to buttress applicator (210) and buttress assemblies (110,112) described above, respectively, except as otherwise described below. In this regard, buttress assembly (412) of this example comprises a buttress body (414) and at least one adhesive bead (416) for adhering buttress body (414) to underside (124) of anvil (18) or to upper deck (72) of staple cartridge (37). In some versions, buttress assembly (412) may have an initial length of approximately 60 mm. Buttress applicator (410) of this example comprises an open end (422) and a closed end (424). Open end (422) is configured to receive end effector (12) in a manner similar to that described above in connection withFIGS.13A-13B. Buttress applicator (410) further includes at least one housing (426) which generally defines a “U” shape to present open end (422). A platform (428) extends longitudinally between proximal and distal ends (429,430) and is exposed in one or more recesses (431) that are formed between the prongs of the “U” configuration of housing (426) and is configured to support buttress assembly (412) on an upper side of platform (428), though platform (428) may just as easily support another buttress assembly (412) on a lower side of platform (428). While buttress assembly (412) is illustrated as a relatively wide version that may unitarily span across slot (42) of anvil (18) or slot (49) of staple cartridge (37), buttress assembly (412) may be provided in a pair of portions that are separated to avoid spanning across either slot (42,49). In any event, housing (426) includes integral gripping features (432), and a plurality of arms (438) are configured to resiliently bear against buttress assembly (412), thereby pinching buttress assembly (412) against platform (428) to selectively secure buttress assembly (412) to platform (428). Housing (426) also includes proximal guide features (446) and distal guide features (448) configured to assist in providing proper alignment of end effector (40) with buttress applicator (410). Buttress applicator (410) of the present example further includes a buttress trimming feature in the form of a laterally-extending slot (450) extending through housing (426) and platform (428) and configured to guide one or more blades of a cutting instrument, such as one or more blades (B1, B2) of scissors (S1), across one or more buttress assemblies (412) to thereby shorten buttress assemblies (412) from the initial length to a predetermined subsequent length. More particularly, slot (450) may guide first blade (B1) to sever a scrap distal portion of buttress assembly (412) on the upper side of platform (428) from a desired proximal portion of buttress assembly (412) having the predetermined subsequent length, and slot (450) may also guide second blade (B2) to sever a scrap distal portion of another buttress assembly (412) on the lower side of platform (428) from a desired proximal portion of buttress assembly (412) having the predetermined subsequent length. In this regard, slot (450) extends laterally across platform (428) thereby bifurcating platform (428), and further extends laterally outwardly from recess (431) and transversely between upper and lower surfaces of housing (426). In some versions, slot (450) may have a width in the longitudinal direction sufficient to slidably receive one or both blades (B1, B2). Slot (450) of the present example defines a cutting line that is generally perpendicular to the longitudinal direction and that is positioned at a predetermined distance from proximal end (429) of platform (428) corresponding to the predetermined subsequent length. For example, slot (450) may be positioned approximately 45 mm from proximal end (429) such that blade(s) (B1, B2) may shorten buttress assemblies (412) to a predetermined subsequent length of approximately 45 mm when guided across buttress assemblies (412) by slot (450). It will be appreciated that slot (450) may be positioned at any other suitable distance from proximal end (429) and/or may be suitably positioned relative to any other reference portion of buttress applicator (410) for facilitating shortening of buttress assemblies (412). While a single slot (450) is shown for facilitating shortening of buttress assemblies (412) to a single predetermined subsequent length, multiple slots (450) may be provided along the length of platform (428) for facilitating shortening of buttress assemblies (412) to any number of predetermined subsequent lengths. In any event, arms (438) may continue to secure the scrap distal portion of buttress assemblies (412) to platform (428) after the desired proximal portion(s) of buttress assemblies (412) has been severed and applied to a corresponding end effector jaw(s) (16,18). While slot (450) is shown bifurcating platform (428), slot (450) may alternatively be separated by platform (428) into a laterally-opposed pair of slots in an arrangement similar to that described above with respect to grooves (350). Also, while slot (450) is shown incorporated into buttress applicator (410) having the configuration described above, it will be appreciated that slot (450) may be readily incorporated into a buttress applicator having any other suitable configuration, such as that described below in connection withFIGS.18A-18C. C. Exemplary Buttress Applicator with Visual Cutting Indicia FIG.16shows another exemplary buttress applicator (510) for applying at least one buttress assembly (512) to at least one jaw of an end effector, such as at least one jaw (16,18) of end effector (12), and configured to facilitate adjustment of the length of buttress assembly (512). Buttress applicator (510) and buttress assembly (512) are similar to buttress applicator (210) and buttress assemblies (110,112) described above, respectively, except as otherwise described below. In this regard, buttress assembly (512) of this example comprises a buttress body (514) and at least one adhesive bead (516) for adhering buttress body (514) to underside (124) of anvil (18) or to upper deck (72) of staple cartridge (37). In some versions, buttress assembly (512) may have an initial length of approximately 60 mm. Buttress applicator (510) of this example comprises an open end (522) and a closed end (524). Open end (522) is configured to receive end effector (12) in a manner similar to that described above in connection withFIGS.13A-13B. Buttress applicator (510) further includes at least one housing (526) which generally defines a “U” shape to present open end (522). A platform (528) extends longitudinally between proximal and distal ends (529,530) and is exposed in one or more recesses (531) that are formed between the prongs of the “U” configuration of housing (526) and is configured to support buttress assembly (512) on an upper side of platform (528), though platform (528) may just as easily support another buttress assembly (512) on a lower side of platform (528). While buttress assembly (512) is illustrated as a relatively wide version that may unitarily span across slot (42) of anvil (18) or slot (49) of staple cartridge (37), buttress assembly (512) may be provided in a pair of portions that are separated to avoid spanning across either slot (42,49). In any event, housing (526) includes integral gripping features (532), and a plurality of arms (538) are configured to resiliently bear against buttress assembly (512), thereby pinching buttress assembly (512) against platform (528) to selectively secure buttress assembly (512) to platform (528). Housing (526) also includes proximal guide features (546) and distal guide features (548) configured to assist in providing proper alignment of end effector (40) with buttress applicator (510). Buttress applicator (510) of the present example further includes a buttress trimming feature in the form of a laterally-opposed pair of cutting indicia (550) provided on housing (526) and identifying a visible path for guiding a blade of a cutting instrument, such as a knife or a scalpel (not shown), across buttress assembly (512) to thereby shorten buttress assembly (512) from the initial length to a predetermined subsequent length. More particularly, indicia (550) may identify the path for guiding such a blade to sever a scrap distal portion of buttress assembly (512) on the upper side of platform (528) from a desired proximal portion of buttress assembly (512) having the predetermined subsequent length. In this regard, indicia (550) each include visually discernible arrows clearly identifying the path by pointing laterally inwardly toward each other. It will be appreciated that indicia (550) may be provided on housing (526) in any suitable manner, such as printing, molding, etching, or stamping, for example. Indicia (550) of the present example collectively define a cutting line that is generally perpendicular to the longitudinal direction and that is positioned at a predetermined distance from proximal end (529) of platform (528) corresponding to the predetermined subsequent length. For example, indicia (550) may be positioned approximately 45 mm from proximal end (529) such that the blade may shorten buttress assembly (512) to a predetermined subsequent length of approximately 45 mm when guided across buttress assembly (512) along the path identified by indicia (550). It will be appreciated that indicia (550) may be positioned at any other suitable distance from proximal end (529) and/or may be suitably positioned relative to any other reference portion of buttress applicator (510) for facilitating shortening of buttress assembly (512). While a single pair of indicia (550) is shown for facilitating shortening of buttress assembly (512) to a single predetermined subsequent length, multiple pairs of indicia (550) may be provided along the length of platform (528) for facilitating shortening of buttress assembly (512) to any number of predetermined subsequent lengths. In any event, arms (538) may continue to secure the scrap distal portion of buttress assembly (512) to platform (528) after the desired proximal portion of buttress assembly (512) has been severed and applied to a corresponding end effector jaw (16,18). While indicia (550) are shown positioned on an upper side of housing (526), indicia (550) may additionally or alternatively be positioned on a lower side of housing (526), such as to identify a visible path for guiding a blade across another buttress assembly (512) on the lower side of platform (528). In some versions, indicia (550) may be provided in conjunction with grooves (350) and/or slot (450), such as in a hybrid configuration of buttress applicator (310) and buttress applicator (510) or in a hybrid configuration of buttress applicator (410) and buttress applicator (510). Also, while indicia (550) are shown incorporated into buttress applicator (510) having the configuration described above, it will be appreciated that indicia (550) may be readily incorporated into a buttress applicator having any other suitable configuration, such as that described below in connection withFIGS.18A-18C. D. Exemplary Buttress Applicator with Integrated Cutting Mechanism FIGS.17A-17Bshow another exemplary buttress applicator (610) for applying at least one buttress assembly (612) to at least one jaw of an end effector, such as at least one jaw (16,18) of end effector (12), and configured to facilitate adjustment of the length of buttress assembly (612). Buttress applicator (610) and buttress assembly (612) are similar to buttress applicator (210) and buttress assemblies (110,112) described above, respectively, except as otherwise described below. In this regard, buttress assembly (612) of this example comprises a buttress body (614) and at least one adhesive bead (616) for adhering buttress body (614) to underside (124) of anvil (18) or to upper deck (72) of staple cartridge (37). In some versions, buttress assembly (612) may have an initial length of approximately 60 mm. Buttress applicator (610) of this example comprises an open end (not shown) and a closed end (624). The open end is configured to receive end effector (12) in a manner similar to that described above in connection withFIGS.13A-13B. Buttress applicator (610) further includes at least one housing (626) which generally defines a “U” shape to present the open end. A platform (628) extends longitudinally between a proximal end (not shown) and a distal end (630) and is exposed in one or more recesses (631) that are formed between the prongs of the “U” configuration of housing (626) and is configured to support buttress assembly (612) on an upper side of platform (628), though platform (628) may just as easily support another buttress assembly (612) on a lower side of platform (628). While buttress assembly (612) is illustrated as a relatively wide version that may unitarily span across slot (42) of anvil (18) or slot (49) of staple cartridge (37), buttress assembly (612) may be provided in a pair of portions that are separated to avoid spanning across either slot (42,49). In any event, housing (626) includes integral gripping features (632), and a plurality of arms (638) are configured to resiliently bear against buttress assembly (612), thereby pinching buttress assembly (612) against platform (628) to selectively secure buttress assembly (612) to platform (628). Housing (626) also includes proximal guide features (not shown) and distal guide features (648) configured to assist in providing proper alignment of end effector (40) with buttress applicator (610). Buttress applicator (610) of the present example further includes a buttress trimming feature in the form of a laterally-opposed pair of cutting elements (650) slidably housed within respective grooves (652) extending partially through housing (626) and configured to guide cutting elements (650) across buttress assembly (612) to thereby shorten buttress assembly (612) from the initial length to a predetermined subsequent length. More particularly, grooves (652) may guide the respective cutting elements (650) to sever a scrap distal portion of buttress assembly (612) on the upper side of platform (628) from a desired proximal portion of buttress assembly (612) having the predetermined subsequent length. In this regard, grooves (652) each extend laterally outwardly from recess (631) and transversely downwardly from an upper surface of housing (626). As shown, grooves (652) each have a width in the longitudinal direction sufficient to slidably receive the respective cutting elements (650). In some versions, grooves (652) may each have a depth in the transverse direction relative to an upper surface of housing (626) generally equal to that of platform (628) such that a base surface of each groove (652) may be substantially flush with the upper surface of platform (628) to assist with maintaining the respective cutting elements (650) at a substantially constant height when guided across buttress assembly (612) by grooves (652). Such a configuration may also inhibit cutting elements (650) from scoring or otherwise cutting platform (328). Cutting elements (650) each include a blade (654) extending laterally inwardly to a respective cutting edge (656), and each further include a manual actuator (658) extending transversely upwardly from a laterally outer end of the respective blade (654). Blades (654) may each be recessed below the upper surface of housing (626) while manual actuators (658) may each protrude at least slightly above the upper surface of housing (626) to enable an operator to grip manual actuators (658) for sliding cutting elements (650) laterally along the respective grooves (652) from a retracted state in which cutting edges (678) are spaced apart from buttress assembly (612) (FIG.17A) to an extended state in which cutting edges (678) pass through buttress assembly (612). As shown, blades (654) may each have a length in the lateral direction sufficiently small to prevent cutting edges (656) from exiting the respective grooves (652) when in the retracted state and sufficiently great to permit cutting edges (656) to reach or slightly surpass a longitudinal centerline of platform (628) when in the extended state for ensuring full severing of buttress assembly (612). While a laterally-opposed pair of cutting elements (650) are shown for cooperating with each other to achieve full severing of buttress assembly (612), in some versions a single cutting element (650) may have a length in the lateral direction sufficiently great to permit such a single cutting element (650) to extend fully across platform (628) and thereby independently sever buttress assembly (612). Grooves (652) of the present example collectively define a cutting line that is generally perpendicular to the longitudinal direction and that is positioned at a predetermined distance from the proximal end of platform (628) corresponding to the predetermined subsequent length. For example, grooves (652) may be positioned approximately 45 mm from the proximal end of platform (628) such that cutting elements (650) may shorten buttress assembly (612) to a predetermined subsequent length of approximately 45 mm when guided across buttress assembly (612) by grooves (652). It will be appreciated that grooves (652) may be positioned at any other suitable distance from the proximal end of platform (628) and/or may be suitably positioned relative to any other reference portion of buttress applicator (610) for facilitating shortening of buttress assembly (612). While a single pair of cutting elements (650) and respective grooves (652) are shown for facilitating shortening of buttress assembly (612) to a single predetermined subsequent length, multiple pairs of cutting elements (650) and respective grooves (652) may be provided along the length of platform (628) for facilitating shortening of buttress assembly (612) to any number of predetermined subsequent lengths. In any event, arms (638) may continue to secure the scrap distal portion of buttress assembly (612) to platform (628) after the desired proximal portion of buttress assembly (612) has been severed and applied to a corresponding end effector jaw (16,18). While cutting elements (650) and grooves (652) are shown positioned on an upper side of housing (626), cutting elements (650) and grooves (652) may additionally or alternatively be positioned on a lower side of housing (626), such as for guiding cutting elements (650) across another buttress assembly (612) on the lower side of platform (628). Also, while cutting elements (650) and grooves (652) are shown incorporated into buttress applicator (610) having the configuration described above, it will be appreciated that cutting elements (650) and grooves (652) may be readily incorporated into a buttress applicator having any other suitable configuration, such as that described below in connection withFIGS.18A-18C. E. Exemplary Alternative Buttress Applicator with Knife Grooves FIGS.18A-18Cshow another exemplary buttress applicator (710) for applying at least one buttress assembly (712) to at least one jaw of an end effector, such as at least one jaw (16,18) of end effector (12), and configured to facilitate adjustment of the length of buttress assembly (712). Buttress applicator (710) and buttress assembly (712) are similar to buttress applicator (210) and buttress assemblies (110,112) described above, respectively, except as otherwise described below. In this regard, buttress assembly (712) of this example comprises a buttress body (714), which may be substantially transparent and/or translucent, and at least one adhesive bead (716) (FIG.18B) for adhering buttress body (714) to underside (124) of anvil (18) or to upper deck (72) of staple cartridge (37). In some versions, adhesive bead (716) may be deposited onto at least a portion of buttress body (714) by the operator, as described in greater detail below. Buttress body (714) may comprise PERI-STRIPS DRY with VERITAS Collagen Matrix (PSDV) reinforcement material, by Baxter Healthcare Corporation of Deerfield, Ill., for example. In addition, or alternatively, buttress assembly (712) may have an initial length of approximately 60 mm. Buttress applicator (710) of this example comprises an open end (722) and a closed end (724). Open end (722) is configured to receive end effector (12) in a manner similar to that described above in connection withFIGS.13A-13B. Buttress applicator (710) further includes at least one housing (726) which generally defines a “U” shape to present open end (722). A platform (728) extends longitudinally between proximal and distal ends (729,730) and is exposed in one or more recesses (731) that are formed between the prongs of the “U” configuration of housing (726) and is configured to support buttress assembly (712) on an upper side of platform (728), though platform (728) may just as easily support another buttress assembly (712) on a lower side of platform (728). While buttress assembly (712) is illustrated as a relatively wide version that may unitarily span across slot (42) of anvil (18) or slot (49) of staple cartridge (37), buttress assembly (712) may be provided in a pair of portions that are separated to avoid spanning across either slot (42,49). In any event, a plurality of flanges (738) are configured to resiliently bear against buttress assembly (712), thereby pinching buttress assembly (712) against platform (728) to selectively secure buttress assembly (712) to platform (728). A buttress retainer (749) is removably coupled to open end (722). Buttress applicator (710) of the present example further includes a buttress trimming feature in the form of a laterally-opposed pair of grooves (750) similar to grooves (350) described above in connection withFIG.14. As shown, grooves (750) extend partially through housing (726) and/or flanges (738) and are configured to guide a blade of a scalpel (S2), across buttress assembly (712) to thereby shorten buttress assembly (712) from the initial length to a predetermined subsequent length. More particularly, grooves (750) may guide scalpel (S2) to sever a scrap distal portion (712b) of buttress assembly (712) on the upper side of platform (728) from a desired proximal portion (712a) of buttress assembly (712) having the predetermined subsequent length, such as approximately 45 mm, as shown inFIG.18A. In some versions, buttress retainer (749) may be removed from open end (722) after scrap distal portion (712b) has been severed from desired proximal portion (712a), and adhesive bead (716) may be deposited onto desired proximal portion (712a) by the operator via an adhesive dispenser (D), as shown inFIG.18B. The operator may then align an end effector, such as end effector (12) with open end (722), position platform (728) and buttress assembly (712) between anvil (18) and staple cartridge (37), close end effector jaws (16,18) on platform (728), thereby adhesively attaching desired proximal portion (712a) of buttress assembly (712) to staple cartridge (37) (or anvil (18)), and disengage end effector jaws (16,18) from platform (728) while desired proximal portion (712a) of buttress assembly (712) remains adhered to staple cartridge (37) (or anvil (18)), as shown inFIG.18C. Flanges (738) may continue to secure scrap distal portion (712b) of buttress assembly (712) to platform (728) after desired proximal portion (712a) of buttress assembly (712) has been severed and applied to staple cartridge (37) (or anvil (18)). While buttress applicator (710) is shown having a buttress trimming feature in the form of grooves (750), buttress applicator (710) may additionally or alternatively have any one or more of the other buttress trimming features described above in connection withFIGS.15-17B. For example, buttress applicator (710) may include a slot similar to slot (450), indicia similar to indicia (550), and/or one or more cutting elements similar to cutting elements (650). F. Exemplary Buttress Applicator Packaging with Integrated Cutting Mechanism In some instances, it may be desirable to integrate a buttress trimming feature into the product packaging for a buttress applicator and the corresponding buttress assemblies.FIGS.19A-19Bshow an exemplary packaging in the form of a tray (800) containing another buttress applicator (810) for applying at least one buttress assembly (812) to at least one jaw of an end effector, such as at least one jaw (16,18) of end effector (12). Tray (800) is configured to facilitate adjustment of the length of buttress assembly (812). Buttress applicator (810) and buttress assembly (812) are similar to buttress applicator (210) and buttress assemblies (110,112) described above, respectively, except as otherwise described below. In this regard, buttress assembly (812) of this example comprises a buttress body (814) and at least one adhesive bead or other type of adhesive layer (not shown) for adhering buttress body (814) to underside (124) of anvil (18) or to upper deck (72) of staple cartridge (37). In some versions, buttress assembly (812) may have an initial length of approximately 60 mm. Buttress applicator (810) of this example comprises an open end (822) and a closed end (824). Open end (822) is configured to receive end effector (12) in a manner similar to that described above in connection withFIGS.13A-13B. Buttress applicator (810) further includes at least one housing (826) which generally defines a “U” shape to present open end (822). A platform (828) extends longitudinally between proximal and distal ends (829,830) and is exposed in one or more recesses (831) that are formed between the prongs of the “U” configuration of housing (826) and is configured to support buttress assembly (812) on an upper side of platform (828), though platform (828) may just as easily support another buttress assembly (812) on a lower side of platform (828). In any event, housing (826) includes integral gripping features (832), and a plurality of arms (838) are configured to resiliently bear against buttress assembly (812), thereby pinching buttress assembly (812) against platform (828) to selectively secure buttress assembly (812) to platform (828). Tray (800) comprises a base (860), a first flap (862), and a first living hinge (864) connecting first flap (862) with base (860). Base (860) of tray (800) is configured to selectively retain applicator (810). First flap (862) is rotatable from a closed position, in which first flap (862) at least partially covers applicator (810) when applicator (810) is retained within base (860) as shown inFIGS.19A-19B, to an open position, in which first flap (862) reveals applicator (810) such that it may be removed from tray (800). In the example shown, an aperture (866) extends through a portion of first flap (862) generally near distal end (830) of platform (828), the purpose of which is described below. Tray (800) of the present example further includes a buttress trimming feature in the form of a cutting element (870) pivotably coupled to base (860) via a second flap (872) and a second living hinge (874) connecting second flap (872) with base (860) above first flap (862). Aperture (866) is configured to guide cutting element (870) through first flap (862) toward buttress assembly (812) to thereby shorten buttress assembly (812) from the initial length to a predetermined subsequent length. More particularly, aperture (866) may guide cutting element (870) to sever a scrap distal portion of buttress assembly (812) on the upper side of platform (828) from a desired proximal portion of buttress assembly (812) having the predetermined subsequent length. In this regard, aperture (866) extends transversely through first flap (862) along a pivot path of cutting element (870). Cutting element (870) includes a blade (876) extending transversely downwardly from second flap (872) to a cutting edge (878). Second flap (872) may be pressed transversely downwardly by the operator for pushed cutting element (870) downwardly through aperture (866) from a retracted state in which cutting edge (878) is spaced apart from buttress assembly (812) (FIG.19A) to an extended state in which cutting edge (878) passes through buttress assembly (812) (FIG.19B). As shown, blade (876) may have a length in the transverse direction sufficiently small to prevent cutting edge (878) from contacting buttress assembly (812) when in the retracted state and sufficiently great to permit cutting edges (656) to pass entirely through buttress assembly (812) when in the extended state for ensuring full severing of buttress assembly (612). In the example shown, a compressible foam block (879) is positioned within aperture (866) for housing at least a portion of blade (876) and/or cutting edge (878) when cutting element (870) is in the retracted state, while permitting cutting edge (878) to exit foam block (879) when cutting element (870) is in the extended state such as by compressing and/or piercing through foam block (879). In some versions, a recess (not shown) may be provided in the upper side of platform (828) for receiving cutting edge (878) when in the extended state to inhibit cutting element (870) from scoring or otherwise cutting platform (828). Cutting edge (878) of the present example defines a cutting line that is generally perpendicular to the longitudinal direction and that is positioned at a predetermined distance from proximal end (829) of platform (828) corresponding to the predetermined subsequent length, at least when cutting element (870) is in the extended state. For example, cutting edge (878) may be positioned approximately 45 mm from proximal end (829) such that cutting element (852) may shorten buttress assembly (812) to a predetermined subsequent length of approximately 45 mm when in the extended state. It will be appreciated that cutting edge (878) may be positioned at any other suitable distance from proximal end (829) and/or may be suitably positioned relative to any other reference portion of buttress applicator (810) or tray (800) for facilitating shortening of buttress assembly (812). In any event, arms (838) may continue to secure the scrap distal portion of buttress assembly (812) to platform (828) after the desired proximal portion of buttress assembly (812) has been severed and applied to a corresponding end effector jaw (16,18). Tray (800) may be further constructed and operable in accordance with any one or more teachings of U.S. Pat. Pub. No. 2020/0205824, entitled “Packaging for Surgical Stapler Buttress,” published Jul. 2, 2020, the disclosure of which is incorporated by reference herein. IV. Exemplary Buttress Assemblies with Variable Length Features As described above, it may be desirable to vary the length of a staple reinforcing adjunct element, such as for modifying the adjunct element to be compatible with an end effector jaw that may be incompatible with an initial length of the adjunct element. For example, an adjunct element may have an initial length (e.g., approximately 60 mm) for use with a first end effector jaw having a first jaw length (e.g., approximately 60 mm). In some instances, it may be desirable to shorten such an adjunct element to a predetermined subsequent length (e.g., approximately 45 mm) such that the adjunct element may be compatible with a second end effector jaw having a second jaw length (e.g., approximately 45 mm). Thus, it may be desirable to provide an adjunct element with one or more variable length features to facilitate adjustment of the length of the adjunct element from the initial length to the predetermined subsequent length prior to or after application of the adjunct element to the end effector jaw. Each of the exemplary buttress assemblies described below provide such functionality. A. Exemplary Buttress Assembly with Notches FIG.20shows an exemplary adjunct element in the form of a buttress assembly (912) having separable proximal and distal portions (912a,912b) configured to facilitate adjustment of the length of buttress assembly (912). Buttress assembly (912) is similar to buttress assemblies (110,112) described above, except as otherwise described below. In this regard, buttress assembly (912) of this example comprises a buttress body (914) extending longitudinally between proximal and distal ends (918,919). Buttress assembly (912) may also comprise at least one adhesive bead or other type of adhesive layer (not shown) for adhering buttress body (914) to underside (124) of anvil (18) or to upper deck (72) of staple cartridge (37). In some versions, buttress assembly (912) may have an initial length of approximately 60 mm. Buttress assembly (912) of the present example further includes a variable length feature in the form of a laterally-opposed pair of notches (980) extending partially through buttress body (914) and identifying a visible path for guiding a blade of a cutting instrument, such as a knife or a scalpel (not shown), across buttress assembly (912) to thereby shorten buttress assembly (912) from the initial length to a predetermined subsequent length. More particularly, notches (980) may identify the path for guiding such a blade to sever a scrap distal portion (912b) of buttress assembly (912) from a desired proximal portion (912a) of buttress assembly (912) having the predetermined subsequent length. In this regard, notches (980) are each generally triangular and extend laterally inwardly from respective lateral edges of buttress body (914) to define respective apexes (982) clearly identifying the path by pointing laterally inwardly toward each other. Notches (980) of the present example and, more particularly, apexes (982), collectively define a cutting line that is generally perpendicular to the longitudinal direction and that is positioned at a predetermined distance from proximal end (918) of buttress body (914) corresponding to the predetermined subsequent length, such that the cutting line delineates proximal and distal portions (912a,912b) of buttress assembly (912). For example, apexes (982) of notches (980) may be positioned approximately 45 mm from proximal end (918) such that the blade may shorten buttress assembly (912) to a predetermined subsequent length of approximately 45 mm when guided across buttress assembly (912) along the path identified by apexes (982) of notches (980). It will be appreciated that apexes (982) of notches (980) may be positioned at any other suitable distance from proximal end (918) and/or may be suitably positioned relative to any other reference portion of buttress assembly (912) for facilitating shortening of buttress assembly (912). In some versions, the position of notches (980) may be fine-tuned to prevent a staple leg from passing through either notch (980) in operations where buttress assembly (1312) is used while maintaining the initial length of buttress assembly (1312). While a single pair of notches (980) is shown for facilitating shortening of buttress assembly (912) to a single predetermined subsequent length, multiple pairs of notches (980) may be provided along the length of buttress body (914) for facilitating shortening of buttress assembly (912) to any number of predetermined subsequent lengths. While notches (980) are shown incorporated into buttress assembly (912) having the configuration described above, it will be appreciated that notches (980) may be readily incorporated into a buttress assembly having any other suitable configuration, such as a generally rectangular configuration similar to that shown inFIGS.18A-18C. Buttress assembly (912) also comprises multiple slits (990) that extend longitudinally along buttress body (914) to generally divide buttress body (914) into two equal sections. Referring toFIG.10, when buttress assembly (912) is used with end effector (12) in a cutting and stapling procedure, cutting edge (48) of firing beam (14) will travel longitudinally through end effector (12) to cut clamped tissue and at the same time cut buttress body (914) of buttress assembly (912) along slits (990). This creates the cut and stapled site as illustrated inFIG.10. Slits (990) act as precuts in buttress body (914) such that during a cutting and stapling action, buttress body (914) offers less resistance to being cut, which promotes buttress body (914) remaining properly placed relative to the surgically cut and stapled site, instead of buttress body (914) being pushed longitudinally by cutting edge (48) and bunching. While the present example uses slits (990) to precut and promote ease of cutting buttress body (914), in view of the teachings herein, other techniques and precut geometries can be used and will be apparent to those of ordinary skill in the art. B. Exemplary Buttress Assembly with Printed Visual Cutting Indicia FIG.21shows another exemplary adjunct element in the form of a buttress assembly (1012) having separable proximal and distal portions (1012a,1012b) configured to facilitate adjustment of the length of buttress assembly (1012). Buttress assembly (1012) is similar to buttress assemblies (110,112) described above, except as otherwise described below. In this regard, buttress assembly (1012) of this example comprises a buttress body (1014) extending longitudinally between proximal and distal ends (1018,1019). Buttress assembly (1012) may also comprise at least one adhesive bead or other type of adhesive layer (not shown) for adhering buttress body (1014) to underside (124) of anvil (18) or to upper deck (72) of staple cartridge (37). In some versions, buttress assembly (1012) may have an initial length of approximately 60 mm. Buttress assembly (1012) of the present example further includes a variable length feature in the form of a laterally-opposed pair of cutting indicia (1080) provided on buttress body (1014) and identifying a visible path for guiding a blade of a cutting instrument, such as a knife or a scalpel (not shown), across buttress assembly (1012) to thereby shorten buttress assembly (1012) from the initial length to a predetermined subsequent length. More particularly, indicia (1080) may identify the path for guiding such a blade to sever a scrap distal portion (1012b) of buttress assembly (1012) from a desired proximal portion (1012a) of buttress assembly (1012) having the predetermined subsequent length. In this regard, indicia (1080) each include visually discernible text clearly identifying the path by stating “45 mm cut line” along the path. It will be appreciated that indicia (1080) may be provided on buttress body (1014) in any suitable manner, such as printing/inking, for example. Indicia (1080) of the present example collectively define a cutting line that is generally perpendicular to the longitudinal direction and that is positioned at a predetermined distance from proximal end (1018) of buttress body (1014) corresponding to the predetermined subsequent length, such that the cutting line delineates proximal and distal portions (1012a,1012b) of buttress assembly (1012). For example, indicia (1080) may be positioned approximately 45 mm from proximal end (1018) such that the blade may shorten buttress assembly (1012) to a predetermined subsequent length of approximately 45 mm when guided across buttress assembly (1012) along the path identified by indicia (1080). It will be appreciated that indicia (1080) may be positioned at any other suitable distance from proximal end (1018) and/or may be suitably positioned relative to any other reference portion of buttress assembly (1012) for facilitating shortening of buttress assembly (1012). While a single pair of indicia (1080) is shown for facilitating shortening of buttress assembly (1012) to a single predetermined subsequent length, multiple pairs of indicia (1080) may be provided along the length of buttress body (1014) for facilitating shortening of buttress assembly (1012) to any number of predetermined subsequent lengths. While indicia (1080) are shown incorporated into buttress assembly (1012) having the configuration described above, it will be appreciated that indicia (1080) may be readily incorporated into a buttress assembly having any other suitable configuration, such as a generally rectangular configuration similar to that shown inFIGS.18A-18C. Buttress assembly (1012) also comprises multiple slits (1090) that extend longitudinally along buttress body (1014) to generally divide buttress body (1014) into two equal sections. Referring toFIG.10, when buttress assembly (1012) is used with end effector (12) in a cutting and stapling procedure, cutting edge (48) of firing beam (14) will travel longitudinally through end effector (12) to cut clamped tissue and at the same time cut buttress body (1014) of buttress assembly (1012) along slits (1090). This creates the cut and stapled site as illustrated inFIG.10. Slits (1090) act as precuts in buttress body (1014) such that during a cutting and stapling action, buttress body (1014) offers less resistance to being cut, which promotes buttress body (1014) remaining properly placed relative to the surgically cut and stapled site, instead of buttress body (1014) being pushed longitudinally by cutting edge (48) and bunching. While the present example uses slits (1090) to precut and promote ease of cutting buttress body (1014), in view of the teachings herein, other techniques and precut geometries can be used and will be apparent to those of ordinary skill in the art. C. Exemplary Buttress Assembly with Visual Cutting Indicia Provided via Change in Material FIG.22shows another exemplary adjunct element in the form of a buttress assembly (1112) having separable proximal and distal portions (1112a,1112b) configured to facilitate adjustment of the length of buttress assembly (1112). Buttress assembly (1112) is similar to buttress assemblies (110,112) described above, except as otherwise described below. In this regard, buttress assembly (1112) of this example comprises a buttress body (1114) extending longitudinally between proximal and distal ends (1118,1119). Buttress assembly (1112) may also comprise at least one adhesive bead (1116) for adhering buttress body (1114) to underside (124) of anvil (18) or to upper deck (72) of staple cartridge (37). In some versions, buttress assembly (1112) may have an initial length of approximately 60 mm. Buttress assembly (1112) of the present example further includes a variable length feature in the form of a cutting indicia (1180) integrated into buttress body (1114) and identifying a visible path for guiding a blade of a cutting instrument, such as a knife or a scalpel (not shown), across buttress assembly (1112) to thereby shorten buttress assembly (1112) from the initial length to a predetermined subsequent length. More particularly, indicia (1180) may identify the path for guiding such a blade to sever a scrap distal portion (1112b) of buttress assembly (1112) from a desired proximal portion (1112a) of buttress assembly (1112) having the predetermined subsequent length. In this regard, indicia (1180) may include a visually discernible color clearly identifying the path by differing from a color of the remainder of buttress body (1114). It will be appreciated that indicia (1180) may be integrated into buttress body (1114) in any suitable manner, such as by forming the portion of buttress body (1114) defining indicia (1180) from a material different from that used to form the remainder of buttress body (1114), for example. Indicia (1180) of the present example defines a cutting line that is generally perpendicular to the longitudinal direction and that is positioned at a predetermined distance from proximal end (1118) of buttress body (1114) corresponding to the predetermined subsequent length, such that the cutting line delineates proximal and distal portions (1112a,1112b) of buttress assembly (1112). For example, indicia (1180) may be positioned approximately 45 mm from proximal end (1118) such that the blade may shorten buttress assembly (1112) to a predetermined subsequent length of approximately 45 mm when guided across buttress assembly (1112) along the path identified by indicia (1180). It will be appreciated that indicia (1180) may be positioned at any other suitable distance from proximal end (1118) and/or may be suitably positioned relative to any other reference portion of buttress assembly (1112) for facilitating shortening of buttress assembly (1112). While a single indicia (1180) is shown for facilitating shortening of buttress assembly (1112) to a single predetermined subsequent length, multiple indicia (1180) may be provided along the length of buttress body (1114) for facilitating shortening of buttress assembly (1112) to any number of predetermined subsequent lengths. While indicia (1180) is shown incorporated into buttress assembly (1112) having the configuration described above, it will be appreciated that indicia (1180) may be readily incorporated into a buttress assembly having any other suitable configuration, such as a generally rectangular configuration similar to that shown inFIGS.18A-18C. D. Exemplary Buttress Assembly with Visual Cutting Indicia Provided Via Manufacturing Process FIG.23shows another exemplary adjunct element in the form of a buttress assembly (1212) having separable proximal and distal portions (1212a,1212b) configured to facilitate adjustment of the length of buttress assembly (1212). Buttress assembly (1212) is similar to buttress assemblies (110,112) described above, except as otherwise described below. In this regard, buttress assembly (1212) of this example comprises a buttress body (1214) extending longitudinally between proximal and distal ends (1218,1219). Buttress assembly (1212) may also comprise at least one adhesive bead (1216) for adhering buttress body (1214) to underside (124) of anvil (18) or to upper deck (72) of staple cartridge (37). In some versions, buttress assembly (1212) may have an initial length of approximately 60 mm. Buttress assembly (1212) of the present example further includes a variable length feature in the form of a cutting indicia (1280) integrated into buttress body (1214) and identifying a visible path for guiding a blade of a cutting instrument, such as a knife or a scalpel (not shown), across buttress assembly (1212) to thereby shorten buttress assembly (1212) from the initial length to a predetermined subsequent length. More particularly, indicia (1280) may identify the path for guiding such a blade to sever a scrap distal portion (1212b) of buttress assembly (1212) from a desired proximal portion (1212a) of buttress assembly (1212) having the predetermined subsequent length. In this regard, indicia (1280) may include a visually discernible color clearly identifying the path by differing from a color of the remainder of buttress body (1214). It will be appreciated that indicia (1280) may be integrated into buttress body (1214) in any suitable manner, such as by subjecting the portion of buttress body (1214) defining indicia (1280) to a color-altering manufacturing process (e.g., UV, chemical, and/or electrical etching) without subjecting the remainder of buttress body (1214) to the color-altering manufacturing process, for example. Indicia (1280) of the present example defines a cutting line that is generally perpendicular to the longitudinal direction and that is positioned at a predetermined distance from proximal end (1218) of buttress body (1214) corresponding to the predetermined subsequent length, such that the cutting line delineates proximal and distal portions (1212a,1212b) of buttress assembly (1212). For example, indicia (1280) may be positioned approximately 45 mm from proximal end (1218) such that the blade may shorten buttress assembly (1212) to a predetermined subsequent length of approximately 45 mm when guided across buttress assembly (1212) along the path identified by indicia (1280). It will be appreciated that indicia (1280) may be positioned at any other suitable distance from proximal end (1218) and/or may be suitably positioned relative to any other reference portion of buttress assembly (1212) for facilitating shortening of buttress assembly (1212). While a single indicia (1280) is shown for facilitating shortening of buttress assembly (1212) to a single predetermined subsequent length, multiple indicia (1280) may be provided along the length of buttress body (1214) for facilitating shortening of buttress assembly (1212) to any number of predetermined subsequent lengths. While indicia (1280) is shown incorporated into buttress assembly (1212) having the configuration described above, it will be appreciated that indicia (1280) may be readily incorporated into a buttress assembly having any other suitable configuration, such as a generally rectangular configuration similar to that shown inFIGS.18A-18C. E. Exemplary Buttress Assembly with Purse String Attachment FIG.24shows another exemplary adjunct element in the form of a buttress assembly (1312) having separable proximal and distal portions (1312a,1312b) configured to facilitate adjustment of the length of buttress assembly (1312). Buttress assembly (1312) is similar to buttress assemblies (110,112) described above, except as otherwise described below. In this regard, buttress assembly (1312) of this example comprises a buttress body (1314) extending longitudinally between proximal and distal ends (1318,1319). Buttress assembly (1312) may also comprise at least one adhesive bead or other type of adhesive layer (not shown) for adhering buttress body (1314) to underside (124) of anvil (18) or to upper deck (72) of staple cartridge (37). In some versions, buttress assembly (1312) may have an initial length of approximately 60 mm. Buttress assembly (1312) of the present example further includes a variable length feature in the form of a purse string suture (1380) removably coupling proximal and distal portions of buttress body (1314) to each other and configured to be selectively removed from buttress assembly (1312) to thereby shorten buttress assembly (1312) from the initial length to a predetermined subsequent length. More particularly, purse string suture (1380) may be pulled from buttress assembly (1312) by the operator to detach a scrap distal portion (1312b) of buttress assembly (1312) from a desired proximal portion (1312a) of buttress assembly (1312) having the predetermined subsequent length, without requiring the use of a blade or other cutting element. Purse string suture (1380) of the present example defines a detachment line that is generally perpendicular to the longitudinal direction and that is positioned at a predetermined distance from proximal end (1318) of buttress body (1314) corresponding to the predetermined subsequent length, such that the cutting line delineates proximal and distal portions (1312a,1312b) of buttress assembly (1312). For example, purse string suture (1380) may be positioned approximately 45 mm from proximal end (1318) such that removal of purse string suture (1380) may shorten buttress assembly (1312) to a predetermined subsequent length of approximately 45 mm. It will be appreciated that purse string suture (1380) may be positioned at any other suitable distance from proximal end (1318) and/or may be suitably positioned relative to any other reference portion of buttress assembly (1312) for facilitating shortening of buttress assembly (1312). In some versions, the position of purse string suture (1380) may be fine-tuned to maximize a number of staples straddling purse string suture (1380) in operations where buttress assembly (1312) is used while maintaining the initial length of buttress assembly (1312). While a single purse string suture (1380) is shown for facilitating shortening of buttress assembly (1312) to a single predetermined subsequent length, multiple purse string sutures (1380) may be provided along the length of buttress body (1314) for facilitating shortening of buttress assembly (1312) to any number of predetermined subsequent lengths. While purse string suture (1380) is shown incorporated into buttress assembly (1312) having the configuration described above, it will be appreciated that purse string suture (1380) may be readily incorporated into a buttress assembly having any other suitable configuration, such as a generally rectangular configuration similar to that shown inFIGS.18A-18C. Buttress assembly (1312) also comprises multiple slits (1390) that extend longitudinally along buttress body (1314) to generally divide buttress body (1314) into two equal sections. Referring toFIG.10, when buttress assembly (1312) is used with end effector (12) in a cutting and stapling procedure, cutting edge (48) of firing beam (14) will travel longitudinally through end effector (12) to cut clamped tissue and at the same time cut buttress body (1314) of buttress assembly (1312) along slits (1390). This creates the cut and stapled site as illustrated inFIG.10. Slits (1390) act as precuts in buttress body (1314) such that during a cutting and stapling action, buttress body (1314) offers less resistance to being cut, which promotes buttress body (1314) remaining properly placed relative to the surgically cut and stapled site, instead of buttress body (1314) being pushed longitudinally by cutting edge (48) and bunching. While the present example uses slits (1390) to precut and promote ease of cutting buttress body (1314), in view of the teachings herein, other techniques and precut geometries can be used and will be apparent to those of ordinary skill in the art. F. Exemplary Buttress Assembly with Bridge Attachment FIG.25shows another exemplary adjunct element in the form of a buttress assembly (1412) having separable proximal and distal portions (1412a,1412b) configured to facilitate adjustment of the length of buttress assembly (1412). Buttress assembly (1412) is similar to buttress assemblies (110,112) described above, except as otherwise described below. In this regard, buttress assembly (1412) of this example comprises a buttress body (1414) extending longitudinally between proximal and distal ends (1418,1419). Buttress assembly (1412) may also comprise at least one adhesive bead or other type of adhesive layer (not shown) for adhering buttress body (1414) to underside (124) of anvil (18) or to upper deck (72) of staple cartridge (37). In some versions, buttress assembly (1412) may have an initial length of approximately 60 mm. Buttress assembly (1412) of the present example further includes a variable length feature in the form of a frangible bridge (1480) removably coupling proximal and distal portions of buttress body (1414) to each other and configured to be selectively removed from buttress assembly (1412) to thereby shorten buttress assembly (1412) from the initial length to a predetermined subsequent length. More particularly, frangible bridge (1480) may be torn or otherwise fractured by the operator to detach a scrap distal portion (1412b) of buttress assembly (1412) from a desired proximal portion (1412a) of buttress assembly (1412) having the predetermined subsequent length, without requiring the use of a blade or other cutting element. In this regard, frangible bridge (1480) may be defined by a structurally weakened portion of buttress body (1410). For example, the remainder of buttress body (1410) may include a mesh of polyglactin910material, laminated between top and bottom layers of a polymeric material, such as polydioxanone (PDO), while the structurally weakened portion of buttress body (1410) defining frangible bridge (1480) may include only the top and bottom layers of polymeric material. In other words, the mesh may not extend across frangible bridge (1480) such that frangible bridge (1480) may be structurally weak relative to the remainder of buttress body (1410). Frangible bridge (1480) of the present example defines a detachment line that is generally perpendicular to the longitudinal direction and that is positioned at a predetermined distance from proximal end (1418) of buttress body (1414) corresponding to the predetermined subsequent length, such that the detachment line delineates proximal and distal portions (1412a,1412b) of buttress assembly (1412). For example, frangible bridge (1480) may be positioned approximately 45 mm from proximal end (1418) such that fracturing of frangible bridge (1480) may shorten buttress assembly (1412) to a predetermined subsequent length of approximately 45 mm. It will be appreciated that frangible bridge (1480) may be positioned at any other suitable distance from proximal end (1418) and/or may be suitably positioned relative to any other reference portion of buttress assembly (1412) for facilitating shortening of buttress assembly (1412). In some versions, the position of frangible bridge (1480) may be fine-tuned to maximize a number of staples straddling frangible bridge (1480) in operations where buttress assembly (1412) is used while maintaining the initial length of buttress assembly (1412). While a single frangible bridge (1480) is shown for facilitating shortening of buttress assembly (1412) to a single predetermined subsequent length, multiple frangible bridges (1480) may be provided along the length of buttress body (1414) for facilitating shortening of buttress assembly (1412) to any number of predetermined subsequent lengths. While frangible bridge (1480) is shown incorporated into buttress assembly (1412) having the configuration described above, it will be appreciated that frangible bridge (1480) may be readily incorporated into a buttress assembly having any other suitable configuration, such as a generally rectangular configuration similar to that shown inFIGS.18A-18C. Buttress assembly (1412) also comprises multiple slits (1490) that extend longitudinally along buttress body (1414) to generally divide buttress body (1414) into two equal sections. Referring toFIG.10, when buttress assembly (1412) is used with end effector (12) in a cutting and stapling procedure, cutting edge (48) of firing beam (14) will travel longitudinally through end effector (12) to cut clamped tissue and at the same time cut buttress body (1414) of buttress assembly (1412) along slits (1490). This creates the cut and stapled site as illustrated inFIG.10. Slits (1490) act as precuts in buttress body (1414) such that during a cutting and stapling action, buttress body (1414) offers less resistance to being cut, which promotes buttress body (1414) remaining properly placed relative to the surgically cut and stapled site, instead of buttress body (1414) being pushed longitudinally by cutting edge (48) and bunching. While the present example uses slits (1490) to precut and promote ease of cutting buttress body (1414), in view of the teachings herein, other techniques and precut geometries can be used and will be apparent to those of ordinary skill in the art. G. Exemplary Buttress Assembly with Separation Gap FIG.26shows another exemplary adjunct element in the form of a buttress assembly (1512) having separable proximal and distal portions (1512a,1512b) configured to facilitate adjustment of the length of buttress assembly (1512). Buttress assembly (1512) is similar to buttress assemblies (110,112) described above, except as otherwise described below. In this regard, buttress assembly (1512) of this example comprises a buttress body (1514) extending longitudinally between proximal and distal ends (1518,1519). Buttress assembly (1512) may also comprise at least one adhesive bead or other type of adhesive layer (not shown) for adhering buttress body (1514) to underside (124) of anvil (18) or to upper deck (72) of staple cartridge (37). In some versions, buttress assembly (1512) may have an initial length of approximately 60 mm. Buttress assembly (1512) of the present example further includes a variable length feature in the form of a gap (1580) separating proximal and distal portions of buttress body (1514) from each other and configured to permit shortening of buttress assembly (1512) from the initial length to a predetermined subsequent length. More particularly, gap (1580) may permit the operator to discard scrap distal portion (1512b) of buttress assembly (1512) without first requiring the operator to detach scrap distal portion (1512b) from a desired proximal portion (1512a) of buttress assembly (1512) having the predetermined subsequent length, without requiring the use of a blade or other cutting element. Gap (1580) of the present example defines a separation line that is generally perpendicular to the longitudinal direction and that is positioned at a predetermined distance from proximal end (1518) of buttress body (1514) corresponding to the predetermined subsequent length, such that the separation line delineates proximal and distal portions (1512a,1512b) of buttress assembly (1512). For example, gap (1580) may be positioned approximately 45 mm from proximal end (1518) such that gap (1580) may permit shortening of buttress assembly (1512) to a predetermined subsequent length of approximately 45 mm. It will be appreciated that gap (1580) may be positioned at any other suitable distance from proximal end (1518) and/or may be suitably positioned relative to any other reference portion of buttress assembly (1512) for facilitating shortening of buttress assembly (1512). In some versions, the position of gap (1580) may be fine-tuned to maximize a number of staples straddling gap (1580) in operations where buttress assembly (1512) is used while maintaining the initial length of buttress assembly (1512). While a single gap (1580) is shown for facilitating shortening of buttress assembly (1512) to a single predetermined subsequent length, multiple gaps (1580) may be provided along the length of buttress body (1514) for facilitating shortening of buttress assembly (1512) to any number of predetermined subsequent lengths. While gap (1580) is shown incorporated into buttress assembly (1512) having the configuration described above, it will be appreciated that gap (1580) may be readily incorporated into a buttress assembly having any other suitable configuration, such as a generally rectangular configuration similar to that shown inFIGS.18A-18C. Buttress assembly (1512) also comprises multiple slits (1590) that extend longitudinally along buttress body (1514) to generally divide buttress body (1514) into two equal sections. Referring toFIG.10, when buttress assembly (1512) is used with end effector (12) in a cutting and stapling procedure, cutting edge (48) of firing beam (14) will travel longitudinally through end effector (12) to cut clamped tissue and at the same time cut buttress body (1514) of buttress assembly (1512) along slits (1590). This creates the cut and stapled site as illustrated inFIG.10. Slits (1590) act as precuts in buttress body (1514) such that during a cutting and stapling action, buttress body (1514) offers less resistance to being cut, which promotes buttress body (1514) remaining properly placed relative to the surgically cut and stapled site, instead of buttress body (1514) being pushed longitudinally by cutting edge (48) and bunching. While the present example uses slits (1590) to precut and promote ease of cutting buttress body (1514), in view of the teachings herein, other techniques and precut geometries can be used and will be apparent to those of ordinary skill in the art. H. Exemplary Buttress Assembly with Perforated Attachment FIG.27shows another exemplary adjunct element in the form of a buttress assembly (1612) having separable proximal and distal portions (1612a,1612b) configured to facilitate adjustment of the length of buttress assembly (1612). Buttress assembly (1612) is similar to buttress assemblies (110,112) described above, except as otherwise described below. In this regard, buttress assembly (1612) of this example comprises a buttress body (1614) extending longitudinally between proximal and distal ends (1618,1619). Buttress assembly (1612) may also comprise at least one adhesive bead or other type of adhesive layer (not shown) for adhering buttress body (1614) to underside (124) of anvil (18) or to upper deck (72) of staple cartridge (37). In some versions, buttress assembly (1612) may have an initial length of approximately 60 mm. Buttress assembly (1612) of the present example further includes a variable length feature in the form of a plurality of perforation slits (1680) positioned between proximal and distal portions of buttress body (1614) and configured to enable tearing of buttress body (1614) therealong to thereby shorten buttress assembly (1612) from the initial length to a predetermined subsequent length. More particularly, buttress body (1614) may be torn or otherwise fractured by the operator along perforation slits (1680) to detach a scrap distal portion (1612b) of buttress assembly (1612) from a desired proximal portion (1612a) of buttress assembly (1612) having the predetermined subsequent length, without requiring the use of a blade or other cutting element. Perforation slits (1680) of the present example collectively define a detachment line that is generally perpendicular to the longitudinal direction and that is positioned at a predetermined distance from proximal end (1618) of buttress body (1614) corresponding to the predetermined subsequent length, such that the detachment line delineates proximal and distal portions (1612a,1612b) of buttress assembly (1612). For example, perforation slits (1680) may be positioned approximately 45 mm from proximal end (1618) such that tearing of buttress body (1614) therealong may shorten buttress assembly (1612) to a predetermined subsequent length of approximately 45 mm. It will be appreciated that perforation slits (1680) may be positioned at any other suitable distance from proximal end (1618) and/or may be suitably positioned relative to any other reference portion of buttress assembly (1612) for facilitating shortening of buttress assembly (1612). In some versions, the position of perforation slits (1680) may be fine-tuned to maximize a number of staples straddling perforation slits (1680) in operations where buttress assembly (1612) is used while maintaining the initial length of buttress assembly (1612). While a single row of perforation slits (1680) is shown for facilitating shortening of buttress assembly (1612) to a single predetermined subsequent length, multiple rows of perforation slits (1680) may be provided along the length of buttress body (1614) for facilitating shortening of buttress assembly (1612) to any number of predetermined subsequent lengths. While perforation slits (1680) are shown incorporated into buttress assembly (1612) having the configuration described above, it will be appreciated that perforation slits (1680) may be readily incorporated into a buttress assembly having any other suitable configuration, such as a generally rectangular configuration similar to that shown inFIGS.18A-18C. Buttress assembly (1612) also comprises multiple slits (1690) that extend longitudinally along buttress body (1614) to generally divide buttress body (1614) into two equal sections. Referring toFIG.10, when buttress assembly (1612) is used with end effector (12) in a cutting and stapling procedure, cutting edge (48) of firing beam (14) will travel longitudinally through end effector (12) to cut clamped tissue and at the same time cut buttress body (1614) of buttress assembly (1612) along slits (1690). This creates the cut and stapled site as illustrated inFIG.10. Slits (1690) act as precuts in buttress body (1614) such that during a cutting and stapling action, buttress body (1614) offers less resistance to being cut, which promotes buttress body (1614) remaining properly placed relative to the surgically cut and stapled site, instead of buttress body (1614) being pushed longitudinally by cutting edge (48) and bunching. While the present example uses slits (1690) to precut and promote ease of cutting buttress body (1614), in view of the teachings herein, other techniques and precut geometries can be used and will be apparent to those of ordinary skill in the art. Exemplary Alternative Buttress Assembly with Notches FIGS.28-29show another buttress applicator (1710) for applying another exemplary buttress assembly (1712) to at least one jaw of an end effector, such as at least one jaw (16,18) of end effector (12). Buttress assembly (1712) has separable proximal and distal portions (1712a,1712b) configured to facilitate adjustment of the length of buttress assembly (1712). Buttress applicator (1710) and buttress assembly (1712) are similar to buttress applicator (210) and buttress assemblies (110,112) described above, respectively, except as otherwise described below. In this regard, buttress assembly (1712) of this example comprises a buttress body (1714), which may be substantially transparent and/or translucent, extending longitudinally between proximal and distal ends (1718,1719). Buttress assembly (1712) may also comprise at least one adhesive bead or other type of adhesive layer (not shown) for adhering buttress body (1714) to underside (124) of anvil (18) or to upper deck (72) of staple cartridge (37). Buttress body (1714) may comprise PERI-STRIPS DRY with VERITAS Collagen Matrix (PSDV) reinforcement material, by Baxter Healthcare Corporation of Deerfield, Ill., for example. In some versions, buttress assembly (1712) may have an initial length of approximately 60 mm. Buttress applicator (1710) of this example comprises an open end (1722) and a closed end (1724). Open end (1722) is configured to receive end effector (12) in a manner similar to that described above in connection withFIGS.13A-13B. Buttress applicator (1710) further includes at least one housing (1726) which generally defines a “U” shape to present open end (1722). A platform (1728) extends longitudinally between a proximal end (not shown) and a distal end (1730) and is exposed in one or more recesses (1731) that are formed between the prongs of the “U” configuration of housing (1726) and is configured to support buttress assembly (1712) on an upper side of platform (1728), though platform (1728) may just as easily support another buttress assembly (1712) on a lower side of platform (1728). While buttress assembly (1712) is illustrated as a relatively wide version that may unitarily span across slot (42) of anvil (18) or slot (49) of staple cartridge (37), buttress assembly (1712) may be provided in a pair of portions that are separated to avoid spanning across either slot (42,49). In any event, a plurality of flanges (1738) are configured to resiliently bear against buttress assembly (1712), thereby pinching buttress assembly (1712) against platform (1728) to selectively secure buttress assembly (1712) to platform (1728). A buttress retainer (1749) is removably coupled to open end (1722). Buttress assembly (1712) of the present example further includes a variable length feature in the form of a laterally-opposed pair of notches (1780) similar to notches (980) described above in connection withFIG.20. As shown, notches (1780) extend partially through buttress body (1714) and identify a visible path for guiding one or more blades (B1, B2) of scissors (S1) across buttress assembly (1712) to thereby shorten buttress assembly (1712) from the initial length to a predetermined subsequent length. More particularly, notches (1780) may identify the path for guiding blade(s) (B1, B2) to sever a scrap distal portion (1712b) of buttress assembly (1712) from a desired proximal portion (1712a) of buttress assembly (1712) having the predetermined subsequent length, as shown inFIG.29. In the version shown, scrap distal portion (1712b) is severed from desired proximal portion (1712a) after desired proximal portion (1712a) of buttress assembly (1712) has been adhesively attached to staple cartridge (37) (or anvil (18)). In other versions, scrap distal portion (1712b) may be severed from desired proximal portion (1712a) while still positioned on the upper side of platform (1728). In such cases, flanges (1738) may continue to secure scrap distal portion (1712b) of buttress assembly (1712) to platform (1728) after desired proximal portion (1712a) of buttress assembly (1712) has been severed and applied to staple cartridge (37) (or anvil (18)). While buttress assembly (1712) is shown having a variable length feature in the form of notches (1780), buttress assembly (1712) may additionally or alternatively have any one or more of the other variable length features described above in connection withFIGS.21-27. For example, buttress assembly (1712) may include indicia similar to any one or more of indicia (1080,1180,1280), a purse string suture similar to purse string suture (1380), a frangible bridge similar to frangible bridge (1480), a gap similar to gap (1580), and/or perforation slits similar to perforation slits (1680). J. Exemplary Buttress Tube with Visual Cutting Indicia FIGS.30A-30Cshow another exemplary buttress assembly (1812) having separable proximal and distal portions (1812a,1812b) configured to facilitate adjustment of the length of buttress assembly (1812), and configured for application to at least one jaw of an end effector, such as at least one jaw (16,18) of end effector (12). Buttress assembly (1812) is similar to buttress assemblies (110,112) described above, except as otherwise described below. In this regard, buttress assembly (1812) of this example comprises a buttress body (1814) extending longitudinally between proximal and distal ends (1818,1819), and further includes an application backing (1816) removably coupled to buttress body (1814) along lateral sides thereof via one or more sutures (not shown) such that buttress assembly (1812) has a generally tubular shape. Backing (1816) may assist with securing buttress body (1814) to upper deck (72) of staple cartridge (37) (or to underside (124) of anvil (18)), such as by capturing upper deck (72) of staple cartridge (37) (or underside (124) of anvil (18)) between buttress body (1814) and backing (1816), as shown inFIG.30A. Buttress body (1814) may comprise NEOVEIL absorbable PGA felt by Gunze Limited, of Kyoto, Japan, for example. In some versions, buttress assembly (1812) may have an initial length of approximately 60 mm. Buttress assembly (1812) of the present example further includes a variable length feature in the form of a cutting indicia (1880) similar to indicia (1080) described above in connection withFIG.21. As shown, indicia (1880) is provided on buttress body (1814) and identifies a visible path (e.g., by including a visually discernible line) for guiding one or more blades (B1, B2) of scissors (S1) across buttress assembly (1812) to thereby shorten buttress assembly (1812) from the initial length to a predetermined subsequent length. More particularly, indicia (1880) may identify the path for guiding blade(s) (B1, B2) to sever a scrap distal portion (1812b) of buttress assembly (1812) from a desired proximal portion (1812a) of buttress assembly (1812) having the predetermined subsequent length, as shown inFIG.30B. In the version shown, scrap distal portion (1812b) is severed from desired proximal portion (1812a) after desired proximal portion (1812a) of buttress assembly (1812) has been secured to staple cartridge (37) (or anvil (18)), as shown inFIG.30C. In other versions, scrap distal portion (1812b) may be severed from desired proximal portion (1812a) prior to securing desired proximal portion (1812a) of buttress assembly (1812) to staple cartridge (37) (or anvil (18)). In any event, the sutures of buttress assembly (1812) may be pulled by the operator after jaws (16,18) have been closed to clamp tissue therebetween, thereby detaching backing (1816) from proximal portion (1812a) of buttress assembly (1812). While buttress assembly (1812) is shown having a variable length feature in the form of indicia (1880), buttress assembly (1812) may additionally or alternatively have any one or more of the other variable length features described above in connection withFIGS.20and22-27. For example, buttress assembly (1812) may include notches similar to notches (980), indicia similar to any one or more of indicia (1180,1280), a purse string suture similar to purse string suture (1380), a frangible bridge similar to frangible bridge (1480), a gap similar to gap (1580), and/or perforation slits similar to perforation slits (1680). K. Exemplary Alternative Cartridge Buttress Assembly with Visual Cutting Indicia FIG.31shows another exemplary buttress assembly (1912) having separable proximal and distal portions (1912a,1912b) configured to facilitate adjustment of the length of buttress assembly (1912), and configured for application to at least one jaw of an end effector, such as lower jaw (16) of end effector (12). Buttress assembly (1912) is similar to buttress assemblies (110,112) described above, except as otherwise described below. In this regard, buttress assembly (1912) of this example comprises a buttress body (1914) extending longitudinally between proximal and distal ends (1918,1919). An application insert (1916) is removably coupled to buttress body (1914) at or near proximal and distal ends (1918,1919). Insert (1916) may assist with application of buttress body (1914) to upper deck (72) of staple cartridge (37). In some versions, buttress assembly (1912) may further include sutures (not shown) configured to secure buttress body (1914) to upper deck (72) of staple cartridge (37). Buttress body (1914) may comprise SEAMGUARD polyglycolic acid:trimethylene carbonate (PGA:TMC) reinforcement material by W.L. Gore & Associates, Inc., of Flagstaff, Ariz., for example. In some versions, buttress assembly (1912) may have an initial length of approximately 60 mm. Buttress assembly (1912) of the present example further includes a variable length feature in the form of a cutting indicia (1980) similar to indicia (1080) described above in connection withFIG.21. As shown, indicia (1980) is provided on buttress body (1914) and identifies a visible path (e.g., by including a visually discernible broken line) for guiding one or more blades (not shown) across buttress assembly (1912) to thereby shorten buttress assembly (1912) from the initial length to a predetermined subsequent length. More particularly, indicia (1980) may identify the path for guiding such a blade to sever a scrap distal portion (1912b) of buttress assembly (1912) from a desired proximal portion (1912a) of buttress assembly (1912) having the predetermined subsequent length. In some versions, scrap distal portion (1912b) is severed from desired proximal portion (1912a) after desired proximal portion (1912a) of buttress assembly (1912) has been secured to staple cartridge (37). In other versions, scrap distal portion (1912b) may be severed from desired proximal portion (1912a) prior to securing desired proximal portion (1912a) of buttress assembly (1912) to staple cartridge (37). In any event, insert (1916) may be detached from proximal portion (1912a) of buttress assembly (1912) by the operator after scrap distal portion (1912b) has been severed from desired proximal portion (1912a). While buttress assembly (1912) is shown having a variable length feature in the form of indicia (1980), buttress assembly (1912) may additionally or alternatively have any one or more of the other variable length features described above in connection withFIGS.20and22-27. For example, buttress assembly (1912) may include notches similar to notches (980), indicia similar to any one or more of indicia (1180,1280), a purse string suture similar to purse string suture (1380), a frangible bridge similar to frangible bridge (1480), a gap similar to gap (1580), and/or perforation slits similar to perforation slits L. Exemplary Alternative Anvil Buttress Assembly with Visual Cutting Indicia FIGS.32-33Cshow another exemplary buttress assembly (2012) having separable proximal and distal portions (2012a,2012b) configured to facilitate adjustment of the length of buttress assembly (2012), and configured for application to at least one jaw of an end effector, such as anvil (18) of end effector (12). Buttress assembly (2012) is similar to buttress assemblies (110,112) described above, except as otherwise described below. In this regard, buttress assembly (2012) of this example comprises a buttress body (2014) extending longitudinally between proximal and distal ends (2018,2019). An application insert (2016) is removably coupled to buttress body (2014) at or near proximal and distal ends (2018,2019). Insert (2016) may assist with application of buttress body (2014) to underside (124) of anvil (18). In some versions, buttress assembly (2012) may further include sutures (not shown) configured to secure buttress body (2014) to underside (124) of anvil (18), as shown inFIG.33A. Buttress body (2014) may comprise SEAMGUARD polyglycolic acid:trimethylene carbonate (PGA:TMC) reinforcement material by W.L. Gore & Associates, Inc., of Flagstaff, Ariz., for example. In some versions, buttress assembly (2012) may have an initial length of approximately 60 mm. Buttress assembly (2012) of the present example further includes a variable length feature in the form of a cutting indicia (2080) similar to indicia (1080) described above in connection withFIG.21. As shown, indicia (2080) is provided on buttress body (2014) and identifies a visible path (e.g., by including a visually discernible broken line) for guiding one or more blades (B1, B2) of scissors (S1) across buttress assembly (2012) to thereby shorten buttress assembly (2012) from the initial length to a predetermined subsequent length. More particularly, indicia (2080) may identify the path for guiding blade(s) (B1, B2) to sever a scrap distal portion (2012b) of buttress assembly (2012) from a desired proximal portion (2012a) of buttress assembly (2012) having the predetermined subsequent length, as shown inFIG.33B. In the version shown, scrap distal portion (2012b) is severed from desired proximal portion (2012a) and desired proximal portion (2012a) is slid proximally along underside (124) of anvil (18) after desired proximal portion (2012a) of buttress assembly (2012) has been positioned over underside (124) of anvil (18), as shown inFIG.33C. In other versions, scrap distal portion (2012b) may be severed from desired proximal portion (2012a) prior to positioning desired proximal portion (2012a) of buttress assembly (2012) over underside (124) of anvil (18). In any event, insert (2016) may be detached from proximal portion (2012a) of buttress assembly (2012) by the operator after scrap distal portion (2012b) has been severed from desired proximal portion (2012a). While buttress assembly (2012) is shown having a variable length feature in the form of indicia (2080), buttress assembly (2012) may additionally or alternatively have any one or more of the other variable length features described above in connection withFIGS.20and22-27. For example, buttress assembly (2012) may include notches similar to notches (980), indicia similar to any one or more of indicia (1180,1280), a purse string suture similar to purse string suture (1380), a frangible bridge similar to frangible bridge (1480), a gap similar to gap (1580), and/or perforation slits similar to perforation slits (1680). V. Exemplary Combinations The following examples relate to various non-exhaustive ways in which the teachings herein may be combined or applied. It should be understood that the following examples are not intended to restrict the coverage of any claims that may be presented at any time in this application or in subsequent filings of this application. No disclaimer is intended. The following examples are being provided for nothing more than merely illustrative purposes. It is contemplated that the various teachings herein may be arranged and applied in numerous other ways. It is also contemplated that some variations may omit certain features referred to in the below examples. Therefore, none of the aspects or features referred to below should be deemed critical unless otherwise explicitly indicated as such at a later date by the inventors or by a successor in interest to the inventors. If any claims are presented in this application or in subsequent filings related to this application that include additional features beyond those referred to below, those additional features shall not be presumed to have been added for any reason relating to patentability. Example 1 An assembly comprising: (a) an applicator, wherein the applicator includes: (i) a housing defining a gap, wherein the gap is configured to receive an end effector jaw of a surgical stapler, and (ii) a platform positioned within the gap, wherein the platform extends longitudinally between a proximal end and a distal end; (b) a first buttress assembly having a first length, wherein the first buttress assembly is positioned on at least a portion of the platform; and (c) at least one trimming feature presented by at least one of the applicator or the first buttress assembly, wherein the at least one trimming feature is configured to facilitate trimming of the first buttress assembly from the first length to a predetermined second length. Example 2 The assembly of Example 1, wherein the at least one trimming feature defines a cutting line, wherein the at least one trimming feature is configured to facilitate trimming of the first buttress assembly from the first length to the predetermined second length along the cutting line. Example 3 The assembly of Example 2, wherein the cutting line is positioned at a predetermined distance from the proximal end. Example 4 The assembly of Example 3, wherein the predetermined distance is approximately 45 mm. Example 5 The assembly of any one or more of Examples 1 through 4, wherein the at least one trimming feature includes at least one groove extending partially through the housing, wherein the at least one groove is configured to guide a blade to facilitate trimming of the first buttress assembly from the first length to the predetermined second length. Example 6 The assembly of Example 5, wherein the at least one groove includes at least one base surface, wherein the at least one base surface is substantially flush with a surface of the platform. Example 7 The assembly of any one or more of Examples 1 through 4, wherein the at least one trimming feature includes at least one slot extending through the housing, wherein the at least one slot is configured to guide at least one blade to facilitate trimming of the first buttress assembly from the first length to the predetermined second length. Example 8 The assembly of Example 7, wherein the at least one slot extends through the platform. Example 9 The assembly of any one or more of Examples 1 through 4, wherein the at least one trimming feature includes at least one visual indicium positioned on the housing, wherein the at least one visual indicia is configured to identify a visible path for a blade to facilitate trimming of the first buttress assembly from the first length to the predetermined second length. Example 10 The assembly of Example 9, wherein the at least one visual indicium includes at least one visually discernible arrow. Example 11 The assembly of any one or more of Examples 1 through 4, wherein the at least one trimming feature includes at least one cutting element movably coupled to the housing to facilitate trimming of the first buttress assembly from the first length to the predetermined second length. Example 12 The assembly of Example 11, further comprising at least one groove extending partially through the housing, wherein the at least one cutting element is slidably disposed within the at least one groove. Example 13 The assembly of any one or more of Examples 1 through 12, wherein the housing defines a U shape. Example 14 The assembly of any one or more of Examples 1 through 13, wherein the first buttress assembly comprises: (i) a body, and (ii) an adhesive, wherein the adhesive is exposed in the gap defined by the housing. Example 15 The assembly of any one or more of Examples 1 through 14, further comprising a second buttress assembly, wherein the first buttress assembly is positioned on a first side of the platform and the second buttress assembly is positioned on a second side of the platform disposed opposite the first side. Example 16 An assembly comprising: (a) a tray, comprising: (i) a base, and (ii) a trimming feature movably coupled to the base; (b) an applicator positioned within the base, the applicator comprising: (i) a housing defining a gap, wherein the gap is configured to receive an end effector jaw of a surgical stapler, and (ii) a platform positioned within the gap; and (c) a first buttress assembly having a first length, wherein the first buttress assembly is positioned on at least a portion of the platform, wherein the trimming feature is operable to trim the first buttress assembly from the first length to a predetermined second length. Example 17 A buttress assembly configured for use with an end effector of a surgical stapler, comprising: (a) a buttress body having a first length, wherein the buttress body is configured to be removably secured to a jaw of the end effector; and (b) at least one variable length feature presented by the buttress body, wherein the at least one variable length feature is configured to facilitate trimming of the buttress body from the first length to a predetermined second length, wherein the buttress body is configured to contact tissue clamped by the end effector during closure thereof, wherein the buttress body is further configured to be pierced and captured by staples ejected from the staple cartridge into the clamped tissue and thereby reinforce the engagement between the ejected staples with the clamped tissue. Example 18 The buttress assembly of Example 17, wherein the buttress body includes a proximal portion and a distal portion, wherein the at least one variable length feature removably couples the proximal and distal portions to each other to facilitate trimming of the buttress body from the first length to the predetermined second length. Example 19 The buttress assembly of Example 17, wherein the at least one variable length feature is configured to identify a visible path for a blade to facilitate trimming of the buttress body from the first length to the predetermined second length. Example 20 A surgical stapler, comprising: (a) a shaft assembly having a distal end; (b) an end effector at the distal end of the shaft assembly, wherein the end effector includes: (i) a first jaw, and (ii) a second jaw, wherein the first and second jaws are operable to clamp tissue therebetween; and (c) the buttress assembly of any one or more of Examples 17 through 19, wherein the buttress body is removably secured to one of the first or second jaws. VI. Miscellaneous It should be understood that any one or more of the teachings, expressions, embodiments, examples, etc. described herein may be combined with any one or more of the other teachings, expressions, embodiments, examples, etc. that are described herein. The above-described teachings, expressions, embodiments, examples, etc. should therefore not be viewed in isolation relative to each other. Various suitable ways in which the teachings herein may be combined will be readily apparent to those of ordinary skill in the art in view of the teachings herein. Such modifications and variations are intended to be included within the scope of the claims. It should be appreciated that any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material. Versions of the devices described above may have application in conventional medical treatments and procedures conducted by a medical professional, as well as application in robotic-assisted medical treatments and procedures. By way of example only, various teachings herein may be readily incorporated into a robotic surgical system such as the DAVINCI™ system by Intuitive Surgical, Inc., of Sunnyvale, Calif. Versions of the devices described above may be designed to be disposed of after a single use, or they can be designed to be used multiple times. Versions may, in either or both cases, be reconditioned for reuse after at least one use. Reconditioning may include any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, some versions of the device may be disassembled, and any number of the particular pieces or parts of the device may be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, some versions of the device may be reassembled for subsequent use either at a reconditioning facility, or by a user immediately prior to a procedure. Those skilled in the art will appreciate that reconditioning of a device may utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application. By way of example only, versions described herein may be sterilized before and/or after a procedure. In one sterilization technique, the device is placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and device may then be placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation may kill bacteria on the device and in the container. The sterilized device may then be stored in the sterile container for later use. A device may also be sterilized using any other technique known in the art, including but not limited to beta or gamma radiation, ethylene oxide, or steam. Having shown and described various embodiments of the present invention, further adaptations of the methods and systems described herein may be accomplished by appropriate modifications by one of ordinary skill in the art without departing from the scope of the present invention. Several of such potential modifications have been mentioned, and others will be apparent to those skilled in the art. For instance, the examples, embodiments, geometrics, materials, dimensions, ratios, steps, and the like discussed above are illustrative and are not required. Accordingly, the scope of the present invention should be considered in terms of the following claims and is understood not to be limited to the details of structure and operation shown and described in the specification and drawings.

11857191

DETAILED DESCRIPTION OF THE INVENTION FIG.1shows a surgical device1for anchoring on the mucous membrane of the inner wall of the intestine10, the device comprising a temporary anchor element2constituted by a first and only semi-rigid hollow longitudinal element defining a wall in the form of a surface of revolution around a longitudinal axis XX having a substantially cylindrical multiply-perforated main portion of substantially circular section referred to as a “first” wall2a, said anchor element2being made of a material that gives it properties of radial elasticity so as to enable it to be compressed radially into a retracted position and to adopt a said maximum radially expanded position after the radial compression has been released, whereby said multiply-perforated wall presents a first outer diameter that can be varied in controlled manner between:a minimum first outer diameter D1′ in said radially retracted position of said first wall, which is preferably no more than 10 mm; anda maximum first outer diameter D1in said maximally radially expanded position of said first wall, preferably lying in the range 18 mm to 45 mm. Said hollow longitudinal element of said first wall2ais a stent of the type made by a mesh of spiral-wound metal wires made of nitinol, as shown diagrammatically inFIG.1A, with the anchoring thereof being modifiable in controlled manner as a function of temperature. It presents properties of radial expansion that are controlled as a function of temperature. More precisely, and as a result of the properties of the nitinol, it expands radially in progressive manner as soon as it is placed at a temperature higher than a temperature of about 20° C. The multiple perforations2a-1of said first wall2acorrespond to the orifices in the mesh made by the spiral-wound mesh of nitinol wires. The dimensional data concerning the data D1′ and D1as given above corresponds to dimensions that are appropriate for anchoring the device against the mucous membrane of the inner wall of the intestine10at various positions between and including the rectum and the esophagus. InFIG.1, the stent2ais covered in a layer2dof polyurethane or of silicone, which is itself multiply-perforated at2d-1on the outer surface of2a. This layer2dprotects the intestinal wall10by avoiding it becoming incrusted by the outer surface of the stent2a. The entire length of the cylindrical inner surface of said first wall2ais lined with an independent leakproof layer forming an inner sheath3, with only the longitudinal ends3a,3bof said inner sheath3being fastened in leaktight manner4a,4bto said anchor element2with the help of first leaktight fastener means4-1a,4-1bconstituting an annular gasket of elastomeric adhesive at each said longitudinal end (3a,3b) of said inner sheath. InFIG.1, said inner sheath3is constituted by a leakproof film forming a flexible tubular wall. The device of the invention also includes an outer sheath7having a tubular wall constituted by a flexible film fastened to said anchor element2at one longitudinal end of said anchor element. InFIG.1, said outer sheath7constitutes an extension of said inner sheath3extending over the outside of said anchor element along the longitudinal direction of said anchor element. The device of the invention also has a flexible or semi-rigid tube referred to as an injection-suction tube6that extends outside said anchor element2. Said inner sheath3is independent of the inner surface of said first wall between these two ends3and3b, so it can be understood that the inner sheath3is not excessively tensioned in order to avoid stiffening the stent, such that the spacing between said inner sheath3and said maximum first outer diameter D1of the first wall2apreferably lies in the range 0.2 mm to 10 mm, more preferably in the range 1 mm to 5 mm, and the space between said inner sheath3and said first wall2adefines a chamber referred to as the “suction” chamber5. An open end of the injection-suction tube constituted by a portion of tubes6ahaving multiple perforations6a-1extends substantially over the entire length of said chamber5in the longitudinal direction XX of the device. The injection-suction tube6opens out into said suction chamber5by passing in leaktight manner through the annular elastomer adhesive gasket at the downstream end3bof the sheath3when the tube6is inserted via the anal orifice, or the gasket at the upstream end3aof the sheath3when the tube6is inserted via the oral orifice. Said injection-suction tube6and said outer sheath7extend outside said anchor element from the same downstream end of said anchor element, and preferably said injection-suction tube6and said outer sheath7are stuck together on the outside of said outer sheath7for anal insertion. The injection-suction tube6serves to inject or suck air or a liquid into or from the chamber5in order to suck the intestinal wall10against the outer face of the stent2aor to separate it therefrom, and more generally in order to modify the anchoring characteristic of the stent2arelative to the intestinal wall10. The layer2dis perforated at2d-1in order to allow the air or the liquid to pass through. InFIG.1, the portion6aof the injection-suction tube6inside the chamber5may be stuck to the inner face of the first wall2aor to the outer face of said outer sheath. In all embodiments, said first wall2apresents:a) a length L1of at least 30 mm, preferably lying in the range 40 mm to 150 mm, and an outer diameter that may be varied in controlled manner between a minimum outer diameter D1′ in the retracted radial position of said first wall of at most 10 mm, and a maximum outer diameter D1in the maximally radially expanded position of said first wall lying in the range 18 mm to 45 mm, preferably in the range 20 mm to 35 mm; andb) its upstream longitudinal end with a flared extension2creferred to as a “collar”, defining a wall in the form of a surface of revolution around said longitudinal axis XX, presenting a section that is circular and of increasing diameter, preferably having a length L1′ lying in the range 5 mm to 30 mm, more preferably a length lying in the range 15 mm to 20 mm, with a maximum diameter D0equal to about 110% of said maximum first diameter, and more particularly lying in the range 21 mm to 37 mm. This collar2cserves to slow down migration of the device1inside the intestine even after its anchoring against the inner wall10of the intestine has been eliminated in the main longitudinal portion or outer surface of the first wall2a. In all embodiments, said outer sheath7presents, at rest, a length L2downstream from said anchor element2of at least 50 cm, preferably at least 1 m, and an outer diameter lying in the range 18 mm to 45 mm, preferably lying in the range 20 mm to 35 mm. InFIG.2, the device of the invention includes a second stent2barranged coaxially inside said first stent2a, said second stent2bbeing constituted by another small enteral prosthesis formed by a mesh of spiral-wound nitinol wires having its outer surface covered in a leakproof film constituting said inner sheath3, said second wall2bdefining a surface of revolution around said longitudinal axis XX having a main portion that is substantially cylindrical of substantially circular section, said second wall presenting a second outer diameter smaller than said first outer diameter of said first wall2a, the longitudinal ends of said second wall2bbeing fastened in leaktight manner to the longitudinal ends of said first wall2aby means of first leaktight fastener means4-1a,4-1bconstituting an annular elastomer adhesive gasket4a,4bat each said longitudinal end of said second wall, so as to define said leaktight suction chamber5laterally, said second hollow cylindrical element being made of a material giving it radial elasticity properties such as to enable it to be compressed radially into said retracted position and to adopt a said maximally radially expanded position after releasing the radial compression in such a manner that said second outer diameter of said second wall2bcan vary in controlled manner between:a minimum second outer diameter D2′ in the radially retracted position of said second wall that is smaller than said minimum first outer diameter;a maximum second outer diameter D2in the maximally radially expanded position of said second wall, that is smaller than said maximum first outer diameter; andthe spacing between said maximum second outer diameter D2and said maximum first outer diameter D1being at least 0.2 mm, preferably lying in the range 0.2 mm to 10 mm, and more preferably lying in the range 1 mm to 5 mm. In this embodiment ofFIG.2, when air is sucked from the outer end of the injection-suction tube6, the suction through the perforations6a-1of the inner tubes portion in the suction chamber5causes the intestinal wall10to be stuck against the outer surface of the first wall2avia the mesh2a-1. However, the space between the inner sheath3and the outer stent2aremains substantially constant, thus making it possible to avoid clogging the perforations6a-1of the tube portion6aand thus enabling the vacuum level inside the suction chamber5to be controlled in more reliable and more uniform manner. This also makes it possible to control the anchor force of the device1against the inner wall10of the intestine in more reliable and more uniform manner. In the embodiment ofFIG.1, there is a risk of the inner sheath3sticking against the perforations6a-1. In this embodiment ofFIG.2, as in the embodiment ofFIG.1, the injection-suction tube6passes through the first fastener means or annular elastomer adhesive gasket4-1bat the downstream end of the anchor element2. InFIG.2, the portion6aof the injection-suction tube6inside the chamber5may be stuck to the outer face of the inner film or sheath3over the outer face of the second wall2b. Advantageously, the outer sheath7is constituted by an extension downstream from the anchor element in the longitudinal direction of said inner sheath3. In a variant, the outer sheath7may be fastened at its upstream end to the same elastomer adhesive gasket4-1bor it may be fastened to the outer face of the downstream longitudinal end of the first wall2aby overlying it over a short portion of its length (not shown in the figures). In an embodiment (not shown in the figures), the upstream end of the sheath7may also cover the outer surface of the second wall2b, thus constituting said inner sheath3or only a portion thereof. FIG.3shows a third embodiment in which said inner sheath3is applied facing the inner surface of the inner stent or second wall2b, i.e. inside it and stuck against it at its longitudinal ends. This likewise provides a suction chamber5presenting substantially permanent radial spacing in the radially expanded position of the first wall2abecause use is made of a multiply-perforated second wall2bas in the above-described embodiment ofFIG.2, which wall is constituted by a stent of smaller diameter. The second stent or inner stent2bdefines a said second multiply-perforated wall2binterposed between said inner sheath3and said first wall2a. The end of said injection-suction tube6aopens out into said suction chamber5between said inner sheath3and said second wall2b, said inner sheath3being constituted by an upstream extension of said outer sheath7constituted by a flexible tubular wall, as inFIG.1. In the embodiment ofFIG.3, the portion6aof the injection-suction tube6that is interposed between the inner sheath3and the second wall2binside the chamber5may be stuck against the inner face of the second wall2b. When air is sucked through the openings6a-1of the tube portion6ain the chamber5, the flexible sheath3is stuck against the tube6aand the intestinal wall10is stuck against the outer face of the outer stent2a, but the space between the two coaxial stents2aand2bis kept constant, as described above, with a spacing of at least 0.2 mm to 10 mm, and preferably lying in the range 1 mm to 5 mm, in the radially extended position of said stent. This leads to the same advantage as in the embodiment ofFIG.2in terms of the ease, the uniformity, and the reliability with which the anchoring of the stent2arelative to the intestinal wall10can be controlled. In the embodiment ofFIG.3, the annular elastomer adhesive gasket4a,4bat each longitudinal end of the main portion of the anchor element2, i.e. at each longitudinal end3a,3bof the inner sheath3and of the first and second walls2aand2b, is constituted by a first annular gasket portion4-1a,4-1bbetween the sheath3cand the second wall2b, and by a second annular gasket portion4-2a,4-2bbetween the two coaxial stents constituting the first wall2aand the second wall2b. FIG.4shows an embodiment with two coaxial stents of nominal diameters for their main portions that are substantially identical. Each stent has a collar2c,2c-1,2c-2at one of its longitudinal ends, as described above, and the two stents2a,2bare engaged coaxially one inside the other head to tail so that the anchor element2has a collar at each of its longitudinal ends. The fact that both stents2aand2bpresent substantially identical nominal diameters, i.e. maximum outer diameters D1and D2, means that the inner stent2bhas its cylindrical main portion constituting said second wall2bengaged as a force-fit against the inner surface of the cylindrical main portion of the first stent or first wall2a. The two stents are stuck one against the other at their longitudinal ends of their said facing cylindrical main portions or first and second walls2a,2b. As shown inFIG.3, the inner sheath3is pressed against the inside of the inner stent, being stuck to said second wall2b, and the inner sheath3thus constitutes the extension of the outer sheath7. As inFIG.3, the injection-suction tube6is pressed against the inner surface of the second wall2bbetween the second wall2band the inner sheath3. More precisely, inFIG.4, the second wall2bor inner stent presents a collar2c-1at its upstream end, while the outer stent or first wall2apresents a collar2c-2at its downstream end, the first and second walls2a,2boverlapping over their entire length. Thus, because the downstream collar2c-2extends the outer stent, it is possible to place the injection-suction tube6so that it extends downstream from the anchor element2so that its open end6aopens out either into the space between the inner sheath3and the second wall2bof the inner stent, as shown inFIG.4, or else in a variant that is not shown, with the open end of the injection-suction tube6opening out into the space between the two stents. More precisely, the portion6aof the tube6may be interposed between the first and second walls2a,2b, i.e. it may be stuck against the outer face of the second wall2b. ThisFIG.4embodiment preserves sufficient space between the inner sheath and the intestinal wall10, thus avoiding clogging of the perforations6ain the end of the injection-suction tube6. In addition, it imparts optimum stiffness to the anchor element2and provides stabilization of sufficient length in the intestinal wall before migrating after the digestive process has restarted. FIG.5Ais a diagram showing an embodiment of the end of the injection-suction tube6constituted by a tube portion6ahaving multiple perforations6a-1, the tube portion extending substantially helically against the inner face of said second wall2b, as shown inFIG.5, following a zigzag or a Z-shaped line and running along the entire length of the suction chamber5. This type of zigzag tube is pressed against the inner face of the second wall2band is stuck thereto. The zigzag or Z-shaped multiply-perforated tube portion6awithin the chamber5may also be pressed against and stuck to the inner surface of the second wall2aor the outer surface of the second wall2bin the embodiment ofFIG.2, by making it run helically lengthwise in the direction XX of the annular chamber5. Three other variants of the device that are not shown are possible:1) a stent2awith two collars and a stent2bwithout a collar;2) a stent2awithout a collar and a stent2bwith only one collar; and3) a stent2awithout a collar and a stent2bwith two collars. FIG.6shows the outer free longitudinal end of said injection-suction tube6reversibly connected to a connection endpiece7including a shutter device consisting in an anti-reflux valve7a, and including an indicator device for indicating the degree of vacuum in the chamber5, which device is constituted by a balloon7b. More precisely, the connection endpiece7comprises a rigid connection rod7cextended by said indicator balloon7bitself co-operating with and extended by the anti-reflux device7a. The connection endpiece7may be connected to a suction appliance, e.g. a syringe8at the free end of the anti-reflux device7a. A connection endpiece7of this type is sold by the supplier Teleflex Medical Company (USA) under the reference Ruschlit PVC No. 1039020353. The anti-reflux device7acomprises an outer hollow cylinder7a-1and an inner hollow central cylinder7a-2. The hollow central cylinder7a-2is guided inside the outer cylinder7a-1by a first abutment7a-3secured to the inner wall of the outer cylinder7a-1and including a central orifice7a-4through which said hollow central cylinder7a-2passes. A second abutment7a-5is secured to said hollow central cylinder7a-2, and a spring7a-6is secured by respective ends to said first abutment7a-3and to said second abutment7a-5so that in the extended position of said spring, a third abutment7a-7secured to the other end of said hollow central cylinder7a-1comes into abutment against a face of the first abutment7a-3. When the end of the syringe8is fitted in the flared end7a-8of said hollow central cylinder7a-1, the bearing force of the syringe serves to compress the spring and separate said first and third abutments7a-3and7a-7so that the air injected by the syringe8can flow from an orifice7a-8at the end of said hollow central cylinder via the passage7a-9between said first and third abutments7a-3and7a-7. After the syringe8has been removed, the spring7a-6returns to its extended position and the third abutment7a-7comes to press against the first abutment7a-3and shut off any passage for air between the outside of the anti-reflux device7aand the inside of the balloon7b. By sucking air into the perforated mini-tube6ausing the syringe8via the connection endpiece7, a vacuum is created in the suction chamber5. The intestinal mucous membrane10is attracted to the outer surface of the stent2aunder the effect of the suction, thereby increasing the anchoring of the device1. Conversely, this effect is canceled by injecting air or a liquid solution into said suction chamber5using the same mini-tube6from the outer free longitudinal end of the injection-suction tube6. As mentioned above, when a liquid solution is injected into the suction chamber5, the temperature of the solution can be used to modify the temperature and thus the shape and the stiffness of the first wall2a, which is made of nitinol alloy. More particularly, at temperatures lower than 15° C., nitinol becomes flexible and malleable, such that introducing a cold liquid in the range 0° C. to 15° C. in the chamber5can make the stent2amalleable, and possibly also the stent2b, thereby facilitating migration of the stent on passing through the anastomosis or through a zone of narrowing, for example. The flexible sheaths3or7may be made using a mixture of various types of silicone, e.g. of the LSR, RTV, and gel types, as described above. WO 2010/092291 describes introducing the device of the invention. It is introduced while in retracted form by means of an introducer4that is constituted by a semi-rigid plastics tube suitable for being deformed and having a diameter lying in the range 3 mm to 20 mm, preferably in the range 10 mm to 15 mm, and a length lying in the range 70 cm to 220 cm, with the anchor element being inserted therein in its retracted shape, said sheath being positioned downstream from the anchor element inside the guide tube of the introducer. Once the guide tube of the introducer has reached the implantation site, e.g. about 1 m upstream from the anastomosis, the anchor element may be moved out from the end of the introducer and it may take up an expanded position. It should be observed that the time required for introducing and moving the anchor element introducer to the implantation site is in practice shorter than the time after which said anchor element is subjected to radial expansion as a result of its temperature increasing because it is inside the body. In its initial shape, in which it is closed and housed inside the introducer, the stent(s)2a,2bpresent(s) a diameter that is very small, in particular lying in the range 5 mm to 15 mm. It is passed through the anastomosis, and then into the upstream intestine. The surgeon assesses progress of the introducer and whether it is properly positioned by palpating the introducer through the walls of the intestine and viewing the stent during its expansion. Once released in the lumen of the intestine, the stent progressively returns to its final diameter. It can be held temporarily in place by the surgeon pinching the stent through the walls of the intestine. The introducer is then withdrawn. The sheath7unfolds spontaneously and progressively as the introducer is withdrawn. The introducer passes back through the anastomosis and then through the anal orifice in the reverse direction, thereby completely releasing the sheath7. After an average period of four days to six days, and under the effect of intestinal contractions, the unit comprising the stent, the outer sheath, and the injection-suction tube migrates progressively towards the anal orifice from its upstream anchor site, which site is far enough upstream from the anastomosis, preferably via at least 20 cm of intestine length, to ensure that the stent reaches the anal orifice five or six days later, only after the digestive process has restarted, after which the device is eliminated with fecal matter. The device of the invention may be combined with other means for a purpose other than protecting an anastomosis. In particular, it may be used for all applications requiring anchoring in the intestine, in particular for the purpose of controlling such anchoring better. Mention is made in particular of devices for increasing the sensation of being sated, as described in US 2008/0208357.

11857192

REFERENCE NUMBERS 1Anastomosis Clamp101,601Outer Rings102,602Inner Lancets103,603Round Corners2Distal end201Thrust Ring202Pulling cable203Transparent Cap204Soft Connection Cap2031,2032Transparent Cap Holes2033Cable Trough2034Connection hole2011,2012Thrust Ring Holes3Middle Flexible sheath301Flexible Outer Pipe302Internal Operation cable4Handle401Core Bar402Slider5Endoscope DETAILED DESCRIPTION OF THE EMBODIMENTS Technical solutions of the present application are described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely used to explain the present application, and are not used to limit the present application. The scope of this application is not limited by these embodiments, and is subjected to the scope of the applied patent. Moreover, to provide clearer descriptions and enable a person skilled in the art to understand the content of this application, all parts in the figures are not necessarily drawn according to relative sizes. The ratio of some sizes to other related scales may be highlighted to be exaggerated, and irrelevant or unimportant details are not completely drawn, for simplicity of the drawings. An anastomosis clamp is provided according to an embodiment of the present application. The anastomosis clamp includes a plurality of outer rings101, round corners103, and inner lancets102that are sequentially connected, wherein all components are arranged in an annular central symmetric way and the whole structure is central symmetric. The plurality of outer rings101is spaced apart and are discontinuous. Adjacent discontinuous outer rings101are connected via four the round corners103. The outer ring101is combined with and connected to the round corner103to form an end-to-end streamline shape that is concaved towards a center of the ring at the round corner103. Each round corner103is provided with one inner lancet102that is pointedly configured. The pointed end of inner lancet102is directed towards a central symmetry point of the outer ring101, for piercing a tissue when the anastomosis clamp clamps. Two round corners103that are curved in opposite directions are connected to form an S-like shape so as to connect the inner lancet102to the outer ring101; in the obtained connection structure, arc transitions are formed between the outer rings101and the round corners103. In this way, the entire connection structure does not have a point where stress is concentrated, thus having higher stability. Regarding the anastomosis clamp according to the present application, the plurality of outer rings101forms a discontinuous and approximately circular ring that does not contain any protruding sharp portions. According to another embodiment, the plurality of outer rings601may also form a discontinuous polygon, with other structures and performances being basically the same or similar to those of the anastomosis clamp according to the embodiment of the circular outer ring101. The anastomosis clamp does not have a sharp part at an outer side, and therefore rarely stimulates a gastrointestinal tract. Thus, after dropping within the gastrointestinal tract, the product is excreted more smoothly along the digestive tract without scratching a side wall of the digestive tract. Regarding the anastomosis clamp of the present application, when the anastomosis clamp is assembled onto the delivery system, the inner lancet thereof is everted from a center of the discontinuous ring, so that the anastomosis clamp in the delivery system to be deployed is in a cylindrical configuration. Regarding the anastomosis clamp of the present application, an outer diameter of the delivery system in its cylindrical configuration is greater than or equal to an outer diameter of the anastomosis clamp that is not assembled. The anastomosis clamp of the present application is made of a hyperelastic material, such as a nickel-titanium alloy material. The present application further provides an anastomosis clamp delivery system for assembling and deploying the anastomosis clamp, wherein the anastomosis clamp delivery system can be used in cooperation with the anastomosis clamp. The anastomosis clamp delivery system of the present application includes a distal end2, a middle flexible sheath3, and a handle4. The distal end2includes a pulling cable202, a transparent cap203, and a soft connection cap204. One end of the soft connection cap204is connected to the transparent cap203, and the other end is connected to an endoscope5. The pulling cable202passes through the transparent cap203and is connected to the handle4via the middle flexible sheath3. The anastomosis clamp1may be assembled within the transparent cap203. The anastomosis clamp1is pressed against the pulling cable202, so that the anastomosis clamp1to be released is in its cylindrical shape. At this time, in the anastomosis clamp1, the outer ring101is in contact with the pulling cable202. In other words, when assembling the anastomosis clamp1, the outer ring101of the anastomosis clamp1is in direct contact with the pulling cable202in the transparent cap203, so that the horizontal pulling cable202is deformed due to a force towards a proximal end. In this case, the anastomosis clamp1may alternatively be that the round corner103is in contact with the pulling cable202while the outer ring101is clamped between the pulling cable202and the transparent cap203. Since the outer ring101is discontinuous, during assembling, several sections of the outer ring101are clamped into a gap between the pulling cable202and the transparent cap203, and are suspended on the pulling cable202. In this way, the pulling cable202is deformed due to a force that is transmitted from the round corner103to a proximal end. It is to be noted that the endoscope5and the transparent cap203may be connected via the soft connection cap204. As an alternative, one end of the transparent cap203may be configured to have a structure that matches with respective end of the endoscope5, such that the end of the transparent cap203may be directly coupled to the endoscope5for connection. Regarding the anastomosis clamp delivery system of the present application, the distal end2may further include a thrust ring201. The thrust ring201is placed in the transparent cap203. The pulling cable202passes and connects the thrust ring201and the transparent cap203. The pulling cable202that passes the thrust ring201and the transparent cap203is connected to the handle4via the middle flexible sheath3. An axial length of the thrust ring201is smaller than that of the transparent cap203. The anastomosis clamp1may be assembled within the transparent cap203. A discontinuous ring formed by the outer rings of the anastomosis clamp abuts against the thrust ring201, so that the anastomosis clamp1to be released is in its cylindrical shape. Regarding the anastomosis clamp delivery system of the present application, the pulling cable202sequentially passes through the thrust ring201and the transparent cap203and connects the two, and forms an Ω-like shape between the thrust ring201and the transparent cap203. Regarding the anastomosis clamp delivery system of the present application, the transparent cap203is a double-layered structure having transparent cap holes2031,2032and a connection hole. Regarding the delivery system of the present application, the anastomosis clamp is sleeved on an inner layer of the transparent cap203, the discontinuous ring formed by the outer rings101of the anastomosis clamp abuts against the thrust ring201, and a tip end of the inner lancet102does not exceed the distal end portion of the transparent cap203. Regarding the delivery system of the present application, the soft connection cap204is made of an elastic material, such as a soft rubber. Regarding the delivery system of the present application, the middle flexible sheath3is disposed along an axial direction of the anastomosis clamp delivery system. Regarding the delivery system of the present application, the pulling cable202is so threaded to first make one end of the pulling cable202pass through two holes at one side of the transparent cap203, make the other end of the pulling cable202pass through two other holes symmetrically arranged at the other side of the transparent cap203, join the two ends of the pulling cable202together, and then connect the joined pulling cable202to the handle4via the middle flexible sheath3. When the distal end2includes the thrust ring201, the pulling cable is so threaded to: first align respective four holes on the transparent cap203and the thrust ring201; then make one end of the pulling cable202sequentially thread into the holes of the transparent cap203and the holes of the thrust ring201, and then sequentially thread out of the holes of the transparent cap203and the holes of the thrust ring201; in a similar way, make the other end of the pulling cable202pass through the four symmetrical holes of the transparent cap203and the thrust ring201; and join the two ends of the pulling cable202together, and then tighten and connect the joined pulling cable to the handle4via the middle flexible sheath3. An inner operation cable302that is in the middle flexible sheath3and is directly connected to the pulling cable202may be replaced by an extension of the pulling cable202. Regarding the delivery system of the present application, after the anastomosis clamp1is assembled, the pulling cable202located between the transparent cap203and the thrust ring201is in an Ω-like shape. Therefore, when deploying the anastomosis clamp1, a movement of the handle4towards a proximal end may drive the pulling cable202to move towards the proximal end, so as to drive the Ω-like shaped pulling cable202between the transparent cap203and the thrust ring201to be deformed. Further, because the pulling cable202is not flexible, after being applied with a force, a bottom portion of the Ω-like shaped pulling cable202tends to be lifted. In this way, the thrust ring201may push the delivery system towards a distal end, and the anastomosis clamp1is released from the delivery system. Compared with an anastomosis clamp delivery system in which a distal end2does not include a thrust ring201, the thrust ring201according to the present invention may provide a more stable deploying process for the anastomosis clamp. Regarding the delivery system of the present application, an end portion of the endoscope5is clamped in the delivery system. Specifically, the soft connection cap204of the distal end of the delivery system is made of an elastic material; the endoscope5is directly inserted into the soft connection cap204, and may clamp an end portion of the endoscope5within the soft connection cap204, such that the endoscope may be fixedly connected to the delivery system. An anastomosis clamp1according to the embodiments of the present application is shown inFIG.1toFIG.5. In a non-limiting embodiment of the present application, the anastomosis clamp includes outer rings101, inner lancets102, and round corners103.FIG.1shows a schematic structural diagram of an anastomosis clamp that is constructed and operated according to an embodiment of the present application.FIG.2is a schematic structural diagram of a to-be-released anastomosis clamp shown inFIG.1.FIG.3is a schematic structural diagram of a to-be-released circular anastomosis clamp in a delivery system shown inFIG.1. The inner lancet102, the round corner103, and the outer ring101are sequentially connected, wherein all components are arranged in a central symmetric way. The round corner103is in an arc configuration that is roughly semi-circular. Several outer rings101form a discontinuous ring with notches at an outermost side of the anastomosis clamp. Adjacent discontinuous outer rings101are connected via four round corners103. The outer ring101is combined with and connected to the round corner103to form an end-to-end streamline shape that is concaved towards a center of the ring at the round corner103. The entire connection structure does not have a point where stress is concentrated. One end of the inner lancet102is connected to the round corner103. The inner lancets102are central-symmetrically designed in a direction from the outer ring101towards the central symmetry point. The other end of the inner lancet102is sharp and is configured to pierce a tissue when the anastomosis clamp clamps. Several sharp corners may further be symmetrically distributed on the inner lancet102, to assist piercing and clamping a tissue to be closed. Adjacent discontinuous outer rings101are connected via four the round corners103. According to a preferable embodiment, between the outer ring101and the inner lancet102and in a direction along which the outer ring101faces towards a center of the discontinuous ring, two arc-shaped round corners103in opposite directions are connected to form an S-like shape that connects the inner lancet102and the outer ring101. In the obtained structure, arc transitions are formed between the outer ring101and the round corner103. The anastomosis clamp of the present application may not only prevent stress from being partially concentrated when its configuration is changed, but also further enables the anastomosis clamp to have higher stability when its configuration is changed. In other words, compared with a design in which the inner lancet102and the outer ring101are connected via a straight line or via another connection manner, the anastomosis clamp of the present application has greater clamping force, and requires greater force when its configuration is changed. The constitutional structure formed by S-like shaped round corners103are axis symmetrically distributed in the direction along which the outer ring101points towards the center of the discontinuous ring. Due to such a structure, a region between the inner lancet102and the outer ring101may be easily deformed elastically, so as to facilitate an arrangement of the anastomosis clamp in the delivery system. In other words, the anastomosis clamp may easily abuts against the thrust ring201, such that the anastomosis clamp in its to-be-released state has a cylindrical configuration. Meanwhile, after being released, the constitutional structure formed by S-like shaped round corners103may resume its original ring configuration promptly to hitch around tissues. When the anastomosis clamp of the present application is in a stationary state, as shown inFIG.1, each outer ring101is in an arc curved shape, such that all outer rings101together form a discontinuous ring structure. This discontinuous ring structure does not have protruding sharp regions on it, thus rarely stimulates a gastrointestinal tract. Further, an anastomosis clamp with such a ring structure may easily drop off within the body, is excreted more smoothly along the digestive tract without scratching a side wall of the digestive tract. Moreover, compared with a prior art anastomosis clamp in which the outer ring101bends inwards, an outer diameter of the anastomosis clamp of the present application in its ring state, provided that the same tissue volume is achieved, will be 20-30% smaller. Therefore, a feeling of foreign object to a patient may be effectively relieved and damages to a surrounding healthy tissue when the anastomosis clamp clamps a tissue may be reduced. As shown inFIG.2andFIG.3, when the anastomosis clamp of the present application is assembled to the delivery system and is in a to-be-released state, the inner lancet102is everted from the center of the discontinuous ring, so that a plane where the inner lancet102is located is substantially perpendicular to a plane where the discontinuous ring is located, such that the anastomosis clamp as a whole has a cylindrical configuration. During this everted process of the inner lancet102, the round corners103are subjected to a torsional force, such that their arc-structure are deformed, causing the S-like shape formed by multiple round corners103to deploy. By this, a distance between adjacent outer rings101tends to be increased, such that an outer diameter of the discontinuous ring formed by the plurality of outer rings101of the anastomosis clamp may be greater than or equal to an outer diameter of the discontinuous ring when the anastomosis clamp is not assembled to the delivery system. The outer ring101of the anastomosis clamp of the present application is in a straight-line shape or in an arc shape that bends outwards, thus may contain a larger area that can be used for clamping tissues. Therefore, if tissue volumes to be clamped are the same, an outer diameter of the anastomosis clamp of the present application is smaller than that of a prior art product.FIG.4shows a schematic diagram of the anastomosis clamp that is released to clamp tissues. The anastomosis clamp of the present application, when being assembled onto the delivery system, is in a cylindrical configuration. Due to a relatively small outer diameter, an axial length of the cylindrical configuration is relatively short. Thus, a delivery system required may have a shorter distal end, thus being easier to pass through a natural orifice of a human body. Moreover, the anastomosis clamp is substantially planar in its un-deformed configuration, facilitating a mounting on the delivery system. The anastomosis clamp may be made of a hyperelastic material, such as a Ni—Ti alloy. A hyperelastic material may have excellent elastic deformation capacity, such that the anastomosis clamp may be adaptively deform from its to-be-released cylindrical configuration to the released planar configuration. At the same time, a hyperelastic material may also have good toughness, such that the inner lancet102may penetrate into tissues for clamping the tissues. The whole structure formed by the inner lancet102, the outer ring101, and the round corner103has a smooth streamline profile. Such a structure does not have a portion where stress is concentrated. Therefore, the anastomosis clamp of the present application may have a higher reliability and stability, may effectively reduce probabilities of being damaged when the anastomosis clamp is in transferred into a to-be-released state due to external force, so that a tissue-clamping function thereof may be realized more stably, thus mitigating secondary injuries brought to the patient due to damage of the anastomosis clamp. FIG.4is a schematic diagram of a released anastomosis clamp according to the present application. After the anastomosis clamp is released by using the delivery system, clamping force may be produced between the tips of the inner lancets102, to well confine a pathological tissue within the outer ring101. To improve penetrating force of the inner lancet102and better protect lining tissues of the human body, the tip of the inner lancet102needs to be ground. It is to be noted that the quantity and shape of the inner lancet102herein are not limited to those shown in the figures. In a non-limiting embodiment of the present application, an anastomosis clamp1includes outer rings601, inner lancets602, and round corners603.FIG.5shows a schematic structural diagram of an anastomosis clamp that is constructed and operated according to another embodiment of the present application. The outer rings601may alternatively be in a polygon structure, i.e., be a single outer ring601that does not have a curved arc region. However, because ends of the outer ring601is connected to the round corner603, there is no protruding sharp portions, therefore, stimulation caused by the anastomosis clamp to the digestive tract may be reduced. Regarding the anastomosis clamp1according to this embodiment, except that the outer rings601together form a polygon structure, other structures and performances are basically the same or similar to those of the anastomosis clamp according to the embodiments of the outer ring101. It is to be noted that the anastomosis clamp of the present application may cooperate with any matching anastomosis clamp delivery system so as to be assembled and released. In a non-limiting embodiment of the present application, as shown inFIG.6toFIG.8, a delivery system suitable for the anastomosis clamp of the present application includes a distal end2, a middle flexible sheath3, and a handle4. The distal end2includes a thrust ring201, a pulling cable202, a transparent cap203, and a soft connection cap204. The middle flexible sheath3includes a flexible outer pipe301and an intermediate operation cable302. The handle4includes a core bar401and a slider402. Among which, the thrust ring201is provided with thrust ring holes2011and2012. The transparent cap203is provided with transparent cap holes2031and2032, a cable trough2033, and a connection hole2034. The intermediate operation cable302may be replaced by an extension of the pulling cable202. FIG.6shows an exploded view of the delivery system. An end close to the handle4is referred to as a proximal end, and an end far away from the handle4is referred to as a distal end. The transparent cap203is a double-layered structure having the transparent cap holes2031and2032, the cable trough2033, and the connection hole2034. The thrust ring201is a single-layered structure having the thrust ring holes2011and2012. The thrust ring201is placed within a middle interbed of the double-layered transparent cap203. The pulling cable202passes and connects the thrust ring201and the transparent cap203. An axial length of the thrust ring201is smaller than that of the transparent cap203. When the anastomosis clamp1is assembled to the delivery system, the inner lancet of the anastomosis clamp1is everted from the center of the discontinuous ring, so that the to-be-released anastomosis clamp1in the delivery system is in a cylindrical configuration. The anastomosis clamp1in a cylindrical configuration is sleeved onto the inner layer of the transparent cap203having the double-layered structure. The outer ring101of the anastomosis clamp1abuts against the thrust ring201. A tip end of the inner lancet does not exceed an end portion of the transparent cap203. One end of the soft connection cap204is sleeved onto the transparent cap203, and the other end is connected to an endoscope5. The soft connection cap204is connected to the endoscope5via snap-fitting. Because the soft connection cap204is made of an elastic material, such as soft PVC, silica gel, or a soft rubber, directly inserting the endoscope5into the soft connection cap204may clamp an end portion of the endoscope5within the soft connection cap204, so as to be fixedly connect the endoscope5to the delivery system. Therefore, the delivery system of the present application and the endoscope may be easily connected, requiring less operation time. The middle flexible sheath3is disposed along an axial direction of the delivery system. A distal end of the intermediate operation cable302passes through the connection hole2034and is connected to the pulling cable202, and the proximal end thereof is connected to the handle4. The distal end2of the delivery system is relatively short. Therefore, the delivery system of the present application has relatively less damages to a side wall of a gastrointestinal tract when passing through the bent gastrointestinal tract. Moreover, because there is no lancet or protrusion along the outer side the entire delivery system, damages to a tissue of the human body may be further reduced. FIG.7AandFIG.7Brespectively are an assembly diagram and a sectional view of a distal end and a part of a middle flexible sheath3of a delivery system of an anastomosis clamp1shown inFIG.6.FIG.8is a threading schematic diagram of a pulling cable in an anastomosis clamp delivery system shown inFIG.6. A specific threading manner of the pulling cable is: first aligning respective four holes on the transparent cap203and the thrust ring201; subsequently, enabling one end of the pulling cable202to first simultaneously thread into the transparent cap hole2031and the thrust ring hole2011, and then sequentially thread out from the thrust ring hole2012and the transparent cap hole2032; enabling, in a same manner, the other end of the pulling cable202to sequentially pass through the four symmetrical holes of the transparent cap203and the thrust ring201; and finally, enabling two ends of the pulling cable to pass into the connection hole2034shown inFIG.7Bafter the two ends of the pulling cable are aligned and joined together, wherein the pulling cable202located between the transparent cap203and the thrust ring201is in an Ω-like shape, as shown inFIG.8, and a body of the pulling cable is rightly embedded into the cable trough2033after the pulling cable202is tightened up. When the anastomosis clamp is released, the handle4is moved towards the proximal end to drive the middle flexible sheath3that is connected to the handle4to move towards the proximal end. Further, because the intermediate operation cable302is connected to the pulling cable202, the movement of the middle flexible sheath3towards the proximal end further drives the pulling cable202that passes through the connection hole2034to move towards the proximal end, so as to drive the pulling cable202that passes through the transparent cap203and the thrust ring201to be deformed. Because the material of the pulling cable202is not elastic, the Ω-like shaped pulling cable202that is located between the transparent cap203and the thrust ring201is deformed after being applied with force. Specifically, both sides of the Ω-like shaped pulling cable202are subjected to pulling force towards the outside, so that the Ω-like shaped pulling cable202tends to be straightened. In this way, the thrust ring201may push the delivery system towards a distal end, and the anastomosis clamp is released from the delivery system. Therefore, when the deploying action takes place, force acting on the anastomosis clamp1comes from two sections of the pulling cable. Meanwhile, since the thrust ring201and the pulling cable202are symmetrically designed, the thrust ring201may move toward the distal end smoothly. Furthermore, the transparent cap203, as an inner structure, may be fitted as a guiding member to complete the action of deploying the anastomosis clamp1. According to an embodiment, the pulling cable202may be made of any material that is suitable for a human body. The material is not limited to a non-metallic material or a metal material; for example, the pulling cable202may be a stainless steel wire, a nickel-titanium wire, a PTFE wire, or the like. During use of the delivery system, a preoperative assessment is made routinely, to determine a condition and a position of a lesion of the patient. The delivery system to which the anastomosis clamp1is mounted in advance is assembled with the endoscope5and is sent to the position with the lesion. An angle of the endoscope5is adjusted. When it is necessary, a wound surface is grasped by an assisting instrument or is sucked via negative pressure into the transparent cap203that is at the distal end. Afterwards, the handle4is moved towards the proximal end to drive the middle flexible sheath3that is connected to the handle4to move towards the proximal end. Meanwhile, the intermediate operation cable302drives the pulling cable202that passes through the connection hole2034to move towards the proximal end, so as to drive the Ω-like shaped pulling cable202that passes through the transparent cap203and the thrust ring201to be deformed, thus the thrust ring201may push the delivery system towards a distal end, and the anastomosis clamp1is released from the delivery system. Since the anastomosis clamp1is made of a hyperelastic material, a certain amount of potential energy will be stored in the anastomosis clamp1that is assembled on a delivery system and takes a cylindrical configuration in a to-be-released state. After the anastomosis clamp1is pushed off from the delivery system, according to the minimum energy principle, since the external force that places restriction on the clamp is removed, the elastic potential energy will be converted into kinetic energy, so that the anastomosis clamp1may quickly clamp a root portion of the wound surface to realize the clamping function. At this time, the anastomosis clamp1will remain planar and stationary when there is no other external force, until a wound tissue completes self healing. Tissues in the clamped region will gangrene and drop due to clamping force, and the anastomosis clamp1is excreted to the outside of the body together with the dropped tissues through a digestive tract. It can be seen that no matter the anastomosis clamp1is planar and stationary or is in a to-be-released state, the outer ring is nearly in an arc shape, thus avoiding unnecessary damages to the human body during use. According to another embodiment of the present application, an anastomosis clamp is provided that includes a plurality of outer rings101, round corners103, and inner lancets102. Among which, an end of an outer ring are successively connected to two round corners103that are curved in opposite directions and are connected to form an S-like shape so as to connect one inner lancet102to the outer ring101. The plurality of outer rings101forms a discontinuous ring shape. One end of an inner lancet102is connected to two S-like structures formed by round corners103, and is located between two adjacent outer rings101, so that these two adjacent outer rings101are axially-symmetric provided with respect to the inner lancet102. The other end of the inner lancet102has a pointed configuration. For example, the anastomosis clamp may include five outer rings101, with a round corner103being provided between any two neighboring outer rings101. One end of the round corner103is connected to one respective outer ring101to form an arc transition at the correspond end of the outer ring101, and the other end of the round corner103is connected to a further round corner103that is curved in an opposite direction for forming the S-like structure. Similarly, the other outer ring101is connected at one of its two ends with a further S-like structure formed by the other two round corner103. The two S-like structures connected to these two neighboring outer rings101are both joined to the same inner lancet102, such that the inner lancet102is formed between two neighboring outer rings101. It may be seen that by the above connection design that consists of outer rings101, round corner103, and inner lancet102, the two symmetrically arranged S-like structures may be connected at one end by the inner lancet102, and the other end their of takes the form of two separate arc transition structures. Therefore, during a process where the inner lancet102folds outwardly, expansion/contraction may occur at the separate arc transition structures, which may lead to an increase of a diameter of the anastomosis clamp in its cylindrical configuration. To release the above anastomosis clamp, according to the embodiment of the present application, there is also provided with a delivery system for deploying the anastomosis clamp that includes a distal end2, a middle flexible sheath3, and a handle4. The distal end2includes a pulling cable202, a transparent cap203, and a soft connection cap204. One end of the soft connection cap204is connected to the transparent cap203, and the other end is connected to an endoscope5. The pulling cable202passes through the transparent cap203and is connected to the handle4via the middle flexible sheath3. The anastomosis clamp1may be assembled within the transparent cap203. The anastomosis clamp1is pressed against the pulling cable202, so that the anastomosis clamp1to be released, being confined by the transparent cap203, is in its cylindrical shape. The distal end2of the delivery system for deploying anastomosis clamp has a shape matching with the shape of the anastomosis clamp1. For example, when the outer rings201of the anastomosis clamp1together form a discontinuous circular ring, the transparent cap203in the distal end2also takes the form of a cylindrical tube; on the other end, when the outer rings201of the anastomosis clamp1together form a discontinuous polygon, the transparent cap203in the distal end2takes the form of a prismatic tube. When deploying the anastomosis clamp1, a pulling force may be applied onto the pulling cable202via the handle4, such that the handle4tends to get straightened so as to drive the anastomosis clamp1towards the distal end, until the anastomosis clamp1slips off the transparent cap203. As the anastomosis clamp1slips off, it is not supported by an inner wall of the transparent cap203any more, thus will resume its planar configuration gradually due to its elasticity for the inner lancets102to clamp tissues.

11857193

DETAILED DESCRIPTION The following description is merely illustrative in nature and is not intended to limit the present disclosure, application, or uses. It will be noted that the first digit of three-digit reference numbers, the first two digits of four-digit reference numbers correspond to the first digit of one-digit figure numbers and the first two-digits of the figure numbers, respectively, in which the element first appears. The following description explains, by way of illustration only and not of limitation, various embodiments of noninvasive apparatuses, systems, and methods for positioning a receiving passage and a donor passage, and suturing the passages together in a surgical anastomosis procedure. The apparatuses, systems, and methods are described using the example of a CABG procedure involving the joining of a saphenous vein to a coronary artery in a CABG procedure. However, it will be appreciated that the same methods, apparatuses, and systems may be used for other grafting or anastomosis procedures for other arteries, intestines, or other bodily passages. Referring toFIG.1, in various embodiments and given by way of illustration only and not of limitation a system100is positioned on a patient's heart102at a receiving passage104. In a non-limiting example given by way of illustration only and not of limitation, in various embodiments the receiving passage104is a coronary artery that may be involved in a CABG procedure. The system100includes a support body110that is configured to physically support and guide other components in a noninvasive anastomosis procedure, as further described below. The system100also includes an eversion mechanism120that is configured to engage and manipulate a portion of the receiving passage104that will become the receiving passage in the CABG procedure, as further described below. As also described further below, the eversion mechanism120is configured to invert only a portion of an edge around an opening (not shown inFIG.1) to be formed in the receiving passage104. The everted portion of the opening in the receiving passage104will engage an everted portion of an end (not shown inFIG.1) of a donor passage106. Non-everted portions of the receiving passage104will be joined to non-everted portions of the end of the donor passage106, as further described below. The eversion mechanism120may include a stabilizer122to secure a position of the heart102and maintain a position of the eversion mechanism120and the rest of the system100relative to the heart102. In various embodiments the system100also includes a donor support mechanism130configured to support the donor passage106. In non-limiting examples included in this description, the donor passage106may be a saphenous vein that may be involved in a CABG procedure. In such embodiments, the donor support mechanism130is used to move the donor passage106into position relative to the receiving passage104for grafting, as described further below. A suturing mechanism (not shown inFIG.1) that is operably coupled with the eversion mechanism120and the donor support mechanism130is used to suture the donor passage106to the receiving passage104, as also described further below with reference toFIG.2and other figures. In an illustrative embodiment, a control conduit140is coupled with the donor support mechanism130for controlling the suturing to complete the graft, as described below. As previously stated, although this description will use for purposes of illustration the non-limiting example of a CABG procedure, it will be appreciated that the same apparatuses, systems, and methods may be used for other anastomosis procedures. Accordingly, in the interest of simplicity, the following description refers only to the example of the donor passage106being grafted to the receiving passage104, although similar procedures may be performed with other donor passages and receiving passages. Referring toFIG.2, in various embodiments a suturing mechanism200includes one or more sets of guide sections210that are disposed around an outside of a passage juncture212formed by surfaces of the receiving passage104and the donor passage106. More specifically, in forming the passage juncture212, a distal edge205of an opening207formed in the receiving passage104is everted, as described below with reference toFIGS.8,9A, and9C. The distal edge205is so designated because of its relative position to a source of blood flow254in the receiving passage104, represented by an arrow inFIG.2. The distal edge205is relatively further removed from the source of the blood flow254than a proximal edge209. The proximal edge209is not everted. In forming the passage juncture212, in various embodiments a distal portion217of an end216of the donor passage106is also everted—where it will be joined to the distal edge205of the receiving passage104. As in the case of the receiving passage104, the distal portion217of the end216of the donor passage is referred to as being distal because of its relative position to a source of blood flow256in the donor passage206, represented by an arrow inFIG.2. The distal portion217is relatively further removed from the source of the blood flow256than a proximal portion215of the end216of the donor passage106. The proximal portion215is not everted. In various embodiments the one or more sets of guide sections210are shaped to surround an outside of passage juncture212formed at the end216of the donor passage106and the opening207in the receiving passage104. An interior surface221of the everted distal portion217of the end216of the donor passage106is positioned against an interior surface211of the everted distal edge205of the receiving passage104. The non-everted proximal portion215of the end216of the donor passage106is positioned against the non-everted proximal edge209of the opening207in the receiving passage104. The non-everted proximal portion215and the non-everted proximal edge209may present a less bulky juncture as compared with the juncture formed by the interior surface221positioned against the interior surface211. As a result, the joint of the non-everted proximal portion215and the non-everted proximal edge209may help present a reduced impairment in a flow of blood into the passage juncture212from sources of the blood flow254and256. In various embodiments inner faces223of the guide sections210present a partial helical channel240along which a needle is motivated to draw a filament to suture the passage juncture212, as described further below with reference toFIGS.12and13. Although not shown inFIG.2, the guide sections210may be joined to or formed integrally with the donor support mechanism130and/or they may be part of a stand-alone suturing mechanism200. Referring toFIG.3, in various embodiments an underside of the support body110supports the eversion mechanism120and the stabilizer122. The eversion mechanism120and the stabilizer122may be coupled to the support body110with a bracket320. The support body110includes a handle311that enables an operator (not shown inFIG.3) to insert the support body110through an opening such as may be formed by an incision, as further described below with reference toFIG.4. After inserting the support body110into the opening, the operator can then manipulate the handle311to position the support body110and, thus, the attached eversion mechanism120and stabilizer122. The operator can withdraw the same after the procedure is completed. The handle311also may convey to the support body110and the bracket320tubing and/or wiring (not shown) to control operation of the system. In various embodiments, the support body110also may include other components to assist the operator in performing the procedure. In various embodiments, the support body110may include an optical system315to aid the operator in guiding the support body110to a desired location and completing the procedure. The optical system315may include a camera312to provide imaging data, via a wired or a wireless connection, to a display (not shown) that may be viewed by the operator. The optical system315also may include a light source314to provide illumination in the vicinity of the support body to facilitate capturing useful optical imaging data with the camera312. Referring toFIG.4, in various embodiments an operator402deploys the support body110(and its associated components) to perform a procedure on a patient403. In the example of a CABG procedure, the support body110may be deployed through a subxiphoid incision404made below the sternum of the patient403. Using the system100and manipulating the support body110and its associated components, the operator402may be able to perform a procedure on the patient403with minimal invasiveness. For example, in the case of a CABG procedure, a conventional procedure would involve a median sternotomy with one or more lengthy incisions and the dividing of the sternum; by contrast, using the system100, the operator may be able to perform the CABG procedure through the much less invasive subxiphoid incision404as shown inFIG.4. Referring toFIGS.5A-7Band continuing with the example of a CABG procedure, in various embodiments the system100can help facilitate performance of a CABG procedure at different locations on the surface of the heart102. Referring toFIGS.5Aand SB, the support body110is positioned to perform a CABG procedure on an anterior surface501of the heart102. A positioning device505may be inserted through the same subxiphoid incision404through which the support body110is inserted into the body. The positioning device505may be used to lift or otherwise position the heart102and hold it in place while the CABG procedure is performed. The positioning device505may be situated with the aid of the optical system315on the support body110(FIG.3). The handle311may be manipulated by the user to direct the support body110to a desired location on the heart102. Surgical tools, such as an endoscopic scalpel591and a manipulating tool593, such as a probe or a pair of forceps, may be used in connection with the system100to complete the procedure, as described further below. Referring toFIGS.6A and6B, in various embodiments the support body110is positioned on a lateral surface601of the heart102. As compared to the situation depicted inFIGS.5A and5B, performing a procedure on the lateral surface610of the heart102may not involve moving the heart102with the positioning device505(FIG.5A). However, various embodiments of the support body110permit rotation of the eversion mechanism120and the stabilizer122relative to the support body110to facilitate disposing the eversion mechanism120and the stabilizer122on the lateral surface601of the heart102. Referring toFIGS.7A and7B, the support body110also may be positioned on an inferior surface701of the heart102. Performing a CABG procedure on the interior surface701of the heart102may not necessitate rotation of the eversion mechanism120and the stabilizer122or use of a positioning device505. The handle311may be manipulated by the user to direct the support body110to a desired location on the heart102. Referring toFIG.8, in various embodiments the CABG procedure proceeds with securing the eversion mechanism120and the stabilizer122in place on the heart102followed by making an incision in the receiving passage104. To proceed with the CABG procedure, the eversion mechanism120is situated directly over the receiving passage104that is to receive the graft, such as from a saphenous vein or other donor passage (not shown inFIG.8). The stabilizer122is then secured to the surface of the heart102to hold the eversion mechanism120in place. The stabilizer122may be connected to a vacuum source (not shown), such as through the control conduit140(FIG.1), so that openings in an underside of the stabilizer122may grip the heart102to hold the stabilizer122and, in turn, the eversion mechanism120in place on the heart102. Alternatively, the stabilizer122may include mechanical grips, such as prongs, to anchor the stabilizer120to the heart102. Once the eversion mechanism120is thus secured in place, a clamp or suture (not shown) may be applied to the receiving passage104ahead of the location where the eversion mechanism120has been positioned (where “ahead” is used to denote the clamp or suture being situated to block the blood flow to the portion of the receiving passage104where the eversion mechanism120is situated). Alternatively, blood flow may be stopped by the application of a tourniquet or another technique of applying direct external pressure to the receiving passage104. After the blood flow has been stopped, the opening207is formed in the receiving passage104within the area bounded by the eversion mechanism801. The opening207may be formed by, for example, making an incision in the receiving passage104, such as by using an endoscopic scalpel591. The endoscopic scalpel591or other cutting tool (not shown) may be inserted through the same subxiphoid incision404through which the support body110was inserted. The formation of the opening207, such as by using the endoscopic scalpel591, may be guided by the optical system315(FIG.3) on the support body110. Referring toFIG.9Aand in various embodiments, after the incision is made to form the opening207, the eversion mechanism120is used to evert the distal edge217of the opening207in the receiving passage104to prepare the receiving passage104to receive the saphenous vein or other donor passage (not shown inFIG.9A). As previously described, in various embodiments, the eversion mechanism120may employ suction from an external source to engage the distal edge205of the opening207and to draw the distal edge205to a rim910of the eversion mechanism120at a distal end991of the rim910. For example, suction may be applied from a vacuum source (not shown) outside the body and conveyed via the control conduit140(FIG.1) to the eversion mechanism120to the openings916(FIGS.9B and9C) in the rim910. The suction may be applied to the rim910via conduits912extending between the stabilizer122and the rim910. The manipulating tool593(not shown inFIG.9A) may be used to push or prod the edges205toward the rim910to aid the suction applied through the rim910in taking hold of the distal edge207along the opening207of the receiving passage104. Suction The proximal edge209along the opening207of the receiving passage104also may be secured in place at a proximal end993of the rim910, such as by applying suction through openings916(FIG.9B) in the rim. However, the proximal edge209, as previously described with reference toFIG.2, is not everted along the opening207in the receiving passage104. Referring toFIG.9B, the proximal edge209of the opening207of the receiving passage104, as previously described with reference toFIG.2, is not everted. The rim910may engage external sides911of the proximal edge209, such as by using suction applied through the openings916to hold external sides911of the receiving passage104in place. Referring toFIG.9C, external sides911of the distal edge205of the receiving passage104are drawn toward the openings916in the rim910. By comparison withFIG.9B, it will be appreciated that the shape of the distal edge991of the rim everts the distal edge205of the receiving artery104while the proximal edge209remains non-everted. The rim910holds the distal edge205and the proximal edge209of the receiving passage104in place to receive the end216of the donor passage106(FIG.2). Referring toFIG.10Aand in various embodiments, the donor support mechanism130is used to position the donor passage106, such as a saphenous vein. The eversion mechanism120and the stabilizer122are put in place over the receiving passage104on the heart102, with the eversion mechanism120everting the distal edge205of the receiving passage104to prepare for grafting as previously described. The donor passage106is then positioned on the donor support mechanism130. Because the donor passage106is removable (and has been harvested from another location in the patient's body to perform the CABG procedure), the donor passage106may be manually positioned on an end1010of the donor support mechanism130. A distal portion1011of the end1010of the donor support mechanism130is shaped to support the distal portion217of the end216of the donor passage106in an everted position. A proximal portion1013of the end101of the donor support mechanism130is shaped to support the proximal portion215of the end216of the donor passage106in a non-everted position. Referring toFIG.10B, in various embodiments the proximal portion215of the end216of the donor passage104, as previously described with reference toFIGS.2and10A, is not everted. The proximal portion215may be held in place by the proximal portion1013of the end1010of the donor support mechanism130, but the proximal portion215is not everted. Referring toFIG.10C, the distal portion217of the end216of the donor passage106is held in place by the distal portion1011of the end1010of the donor support mechanism130in an everted position. By comparison withFIG.10B, it is the shape of the distal portion1011that presents the distal portion217in an everted position. The end1010of the donor support mechanism130holds the distal portion217and the proximal portions215of the donor passage106in place to be positioned against the opening207of the donor passage106(FIG.2) for grafting. Referring again toFIG.10A, in various embodiments the donor support mechanism130includes two segments1031and1033that meet at a joint1032. The two segments1031and1033are held together when the donor passage106is inserted into the donor support mechanism130and the edges209of the end211of the donor passage106are drawn back over the end1010of the donor support mechanism130. After the donor passage106is sutured to the receiving passage104, the segments1031and1033are removed from one another at the joint1032and removed from around the donor passage106. Thus, the donor support mechanism.130is removable after the CABG procedure, thereby leaving the sutured donor passage106in place. The segments1031and1033may incorporate the guide sections210(not shown inFIG.10A) for facilitating the suturing of the graft. Referring toFIGS.11A and11B, in various embodiments the donor support mechanism130is moved into place over the eversion mechanism120to perform the CABG procedure. Referring toFIG.11A, the donor support mechanism130supports the donor passage106to prepare for the anastomosis procedure. Referring toFIG.11B, the donor support mechanism130is moved into place over the eversion mechanism120to form the passage juncture212. The donor passage106may then be sutured to the receiving passage104to complete the CABG procedure. Referring toFIG.12, in various embodiments the guide sections210of the suturing mechanism200are positioned around a periphery of the passage juncture212formed by the end216of the donor passage206and the opening207in the receiving passage104. In various embodiments, the guide sections210are mounted on or integrally formed as part of the donor support mechanism130. Thus, when the donor support mechanism130(to which the donor passage106is secured as previously described with reference toFIGS.10A-10C) is moved into place over the eversion mechanism120(to which the receiving passage104is secured as described with reference toFIGS.9A-9C), the passage junction212formed thereby is ready to be sutured. The partial helical channel240defined in the faces223of the guide sections210(FIG.2) surrounds the passage junction212from the outside. With the partial helical channel240in place around an outside of the passage junction212, the helical needle280is motivated along the partial helical channel240to complete the graft with sutures1290. Referring toFIG.13, in various embodiments the helical needle280is configured to conform to the partial helical channel240. A pointed leading end1392is configured to pierce the tissue of the receiving passage104and the donor passage106as the helical needle280moves along the partial helical channel240. A trailing end1394is coupled with or configured to be attached to a filament290. The needle280is thus able to direct the filament290along a helical path to suture the receiving passage104and the donor passage106to complete the grafting procedure. Referring toFIG.14, in various embodiments an illustrative method1400of performing an anastomosis procedure is provided. The method1400starts at a block1405. At a block1410, a distal portion of an end of the donor passage is everted, while a proximal portion of the end of the donor passage remains in a non-everted position. At a block1420, a distal portion of an opening of a receiving passage is everted, while a proximal portion of the opening of the receiving passage remains in a non-everted position. At a block1430, a passage juncture is formed with the end of the donor passage adjacent to the opening of the receiving passage. At a block1440, a filament is motivated along a generally helical path around the passage juncture to suture the donor passage to the receiving passage. The method1400ends at a block1445, with the passage juncture sutured together to complete the grafting of the donor passage and the receiving passage. It will be appreciated that the detailed description set forth above is merely illustrative in nature and variations that do not depart from the gist and/or spirit of the claimed subject matter are intended to be within the scope of the claims. Such variations are not to be regarded as a departure from the spirit and scope of the claimed subject matter.

11857194

DETAILED DESCRIPTION OF EMBODIMENTS Embodiments of the presently disclosed surgical devices, and adapter assemblies for surgical devices and/or handle assemblies are described in detail with reference to the drawings, in which like reference numerals designate identical or corresponding elements in each of the several views. As used herein the term “distal” refers to that portion of the adapter assembly or surgical device, or component thereof, farther from the user, while the term “proximal” refers to that portion of the adapter assembly or surgical device, or component thereof, closer to the user. A surgical device, in accordance with an embodiment of the present disclosure, is a handheld surgical device in the form of a powered electromechanical handle assembly configured for selective attachment thereto of a plurality of different reloads, via a plurality of respective adapter assemblies, that are each configured for actuation and manipulation by the powered electromechanical handle assembly. The surgical device includes a handle assembly100which is configured for selective connection with an adapter assembly200, and, in turn, adapter assembly200is configured for selective connection with a selected reload400(of a plurality of reloads), which are configured to produce a surgical effect on tissue of a patient. As illustrated inFIGS.1-11, handle assembly100includes a power handle101, and an outer shell housing10configured to selectively receive and encase power handle101. Outer shell housing10includes a distal half-section10aand a proximal half-section10bpivotably connected to distal half-section10aby a hinge16located along an upper edge of distal half-section10aand proximal half-section10b. When joined, distal and proximal half-sections10a,10bdefine a shell cavity10ctherein in which power handle101is selectively situated. Distal and proximal half-sections10a,10bof shell housing10are divided along a plane that traverses a longitudinal axis “X” of adapter assembly200. Each of distal and proximal half-sections10a,10bof shell housing10includes a respective upper shell portion12a,12b, and a respective lower shell portion14a,14b. Lower shell portions14a,14bdefine a snap closure feature18for selectively securing lower shell portions14a,14bto one another and for maintaining shell housing10in a closed condition. Shell housing10includes right-side and left-side snap closure features18afor further securing distal and proximal half-sections10a,10bof shell housing10to one another. Distal half-section10aof shell housing10defines a connecting portion20configured to accept a corresponding drive coupling assembly210of Adapter assembly200. Specifically, distal half-section10aof shell housing10has a recess20that receives a portion of drive coupling assembly210of Adapter assembly200when Adapter assembly200is mated to handle assembly100. Connecting portion20of distal half-section10adefines a pair of axially extending guide rails20a,20bprojecting radially inward from inner side surfaces thereof. Guide rails20a,20bassist in rotationally orienting Adapter assembly200relative to handle assembly100when Adapter assembly200is mated to handle assembly100. Connecting portion20of distal half-section10adefines three apertures22a,22b,22cformed in a distally facing surface thereof and which are arranged in a common plane or line with one another. Connecting portion20of distal half-section10aalso defines an elongate slot24(to contain connector66, seeFIG.3) also formed in the distally facing surface thereof. Connecting portion20of distal half-section10afurther defines a female connecting feature26(seeFIG.2) formed in a surface thereof. Female connecting feature26selectively engages with a male connecting feature of Adapter assembly200, as will be described in greater detail below. Distal half-section10aof shell housing10supports a distal facing toggle control button30. Toggle control button30is capable of being actuated in a left, right, up and down direction upon application of a corresponding force thereto or a depressive force thereto. Distal half-section10aof shell housing10supports a right-side pair of control buttons32a,32b(seeFIG.3); and a left-side pair of control button34a,34b(seeFIG.2). Right-side control buttons32a,32band left-side control buttons34a,34bare capable of being actuated upon application of a corresponding force thereto or a depressive force thereto. Proximal half-section10bof shell housing10supports a right-side fire button36a(seeFIG.3) and a left-side fire button36b(seeFIG.2). Right-side fire button36aand left-side fire button36bare capable of being actuated upon application of a corresponding force thereto or a depressive force thereto. Distal half-section10aand proximal half-section10bof shell housing10are fabricated from a polycarbonate, and are clear or transparent or may be overmolded. With reference toFIGS.5-11, handle assembly100includes an insertion guide50that is configured and shaped to seat on and entirely surround a distal facing edge10d(FIGS.3and9) of proximal half-section10b. Insertion guide50includes a body portion52defining a central opening therein, and a hand/finger grip tab54extending from a bottom of body portion52. In use, when body portion52of insertion guide50is seated on distal facing edge10dof proximal half-section10b, the central opening of insertion guide50provides access to shell cavity10cof shell housing10for insertion of a non-sterile power handle101of handle assembly100into proximal half-section10bof sterile shell housing10. With reference toFIGS.2-4, shell housing10includes a sterile barrier plate assembly60selectively supported in distal half-section10a. Specifically, sterile barrier plate assembly60is disposed behind connecting portion20of distal half-section10aand within shell cavity10cof shell housing10. Plate assembly60includes a plate62rotatably supporting three coupling shafts64a,64b,64c. Each coupling shaft64a,64b,64cextends from opposed sides of plate62and has a tri-lobe transverse cross-sectional profile. Each coupling shaft64a,64b,64cextends through a respective aperture22b,22c,22aof connecting portion20of distal half-section10awhen sterile barrier plate assembly60is disposed within shell cavity10cof shell housing10. Plate assembly60further includes an electrical connector66supported on plate62. Electrical connector66extends from opposed sides of plate62. Each coupling shaft64a,64b,64cextends through respective aperture22a,22b,22cof connecting portion20of distal half-section10aof shell housing10when sterile barrier plate assembly60is disposed within shell cavity10cof shell housing10. Electrical connector66includes a chip and defines a plurality of contact paths each including an electrical conduit for extending an electrical connection across plate62. When plate assembly60is disposed within shell cavity10cof shell housing10, distal ends of coupling shaft64a,64b,64cand a distal end of pass-through connector66are disposed or situated within connecting portion20of distal half-section10aof shell housing10, and electrically and/or mechanically engage respective corresponding features of Adapter assembly200, as will be described in greater detail below. In operation, with a new and/or sterile shell housing10in an open configuration (e.g., distal half-section10aseparated from proximal half-section10b, about hinge16), and with insertion guide50in place against the distal edge10dof proximal half-section10bof shell housing10, power handle101is inserted through the central opening of insertion guide50and into shell cavity10cof shell housing10. With power handle101inserted into shell cavity10cof shell housing10, insertion guide50is removed from proximal half-section10band distal half-section10ais pivoted, about hinge16, to a closed configuration for shell housing10. In the closed configuration, snap closure feature18of lower shell portion14aof distal half-section10aengages snap closure feature18of lower shell portion14bof proximal half-section10b. Also, right-side and left-side snap closure features18aengage to further maintain shell housing10in the closed configuration. In operation, following a surgical procedure, snap closure feature18of lower shell portion14aof distal half-section10ais disengaged from snap closure feature18of lower shell portion14bof proximal half-section10b, and right-side and left-side snap closure features18aare disengaged, such that distal half-section10amay be pivoted, about hinge16, away from proximal half-section10bto open shell housing10. With shell housing10open, power handle101is removed from shell cavity10cof shell housing10(specifically from proximal half-section10bof shell housing10), and shell housing10is discarded. Power handle101is then disinfected and cleaned. Power handle101is not to be submerged and is not to be sterilized. Referring toFIGS.3-6andFIGS.12-19, handle assembly100includes a power handle101. Power handle101includes an inner handle housing110having a lower housing portion104and an upper housing portion108extending from and/or supported on lower housing portion104. Lower housing portion104and upper housing portion108are separated into a distal half-section110aand a proximal half-section110bconnectable to distal half-section110aby a plurality of fasteners. When joined, distal and proximal half-sections110a,110bdefine an inner handle housing110having an inner housing cavity110ctherein in which a power-pack core assembly106is situated. Power-pack core assembly106is configured to control the various operations of handle assembly100, as will be set forth in additional detail below. Distal half-section110aof inner handle housing110defines a distal opening111atherein which is configured and adapted to support a control plate160of power-pack core assembly106. Control plate160of power handle101abuts against a rear surface of plate62of sterile barrier plate assembly60of shell housing10when power handle101is disposed within shell housing10. With reference toFIG.12, distal half-section110aof inner handle housing110supports a distal toggle control interface130that is in operative registration with distal toggle control button30of shell housing10. In use, when power handle101is disposed within shell housing10, actuation of toggle control button30exerts a force on toggle control interface130. Distal half-section110aof inner handle housing110also supports a right-side pair of control interfaces132a,132b, and a left-side pair of control interfaces134a,134b. In use, when power handle101is disposed within shell housing10, actuation of one of the right-side pair of control buttons32a,32bor the left-side pair of control button34a,34bof distal half-section10aof shell housing10exerts a force on a respective one of the right-side pair of control interfaces132a,132bor the left-side pair of control interfaces134a,134bof distal half-section110aof inner handle housing110. In use, control button30, right-side fire button36aor the left-side fire button36b, the right-side pair of control interfaces132a,132b, and the left-side pair of control interfaces134a,134bof distal half-section110aof inner handle housing110will be deactived or fail to function unless shell housing10has been validated. Proximal half-section110bof inner handle housing110defines a right-side control aperture136aand a left-side control aperture136b. In use, when power handle101is disposed within shell housing10, actuation of one of the right-side fire button36aor the left-side fire button36bof proximal half-section10bof shell housing10extends the right-side fire button36aor the left-side fire button36binto and across the right-side control aperture136aor the left-side control aperture136bof the proximal half-section110bof inner handle housing110. With reference toFIGS.12-19, inner handle housing110provides a housing in which power-pack core assembly106is situated. Power-pack core assembly106includes a battery circuit140, a controller circuit board142and a rechargeable battery144configured to supply power to any of the electrical components of handle assembly100. Controller circuit board142includes a motor controller circuit board142a, a main controller circuit board142b, and a first ribbon cable142cinterconnecting motor controller circuit board142aand main controller circuit board142b. Power-pack core assembly106further includes a display screen146supported on main controller circuit board142b. Display screen146is visible through a clear or transparent window110d(seeFIGS.12and17) provided in proximal half-section110bof inner handle housing110. Power-pack core assembly106further includes a first motor152, a second motor154, and a third motor156each electrically connected to controller circuit board142and battery144. Motors152,154,156are disposed between motor controller circuit board142aand main controller circuit board142b. Each motor152,154,156includes a respective motor shaft152a,154a,156aextending therefrom. Each motor shaft152a,154a,156ahas a tri-lobe transverse cross-sectional profile for transmitting rotative forces or torque. Each motor152,154,156is controlled by a respective motor controller. The motor controllers are disposed on motor controller circuit board142aand are A3930/31K motor drivers from Allegro Microsystems, Inc. The A3930/31K motor drivers are designed to control a 3-phase brushless DC (BLDC) motor with N-channel external power MOSFETs, such as the motors152,154,156. Each of the motor controllers is coupled to a main controller disposed on the main controller circuit board142b. The main controller is also coupled to memory, which is also disposed on the main controller circuit board142b. The main controller is an ARM Cortex M4 processor from Freescale Semiconductor, Inc, which includes 1024 kilobytes of internal flash memory. The main controller communicates with the motor controllers through an FPGA, which provides control logic signals (e.g., coast, brake, etc.). The control logic of the motor controllers then outputs corresponding energization signals to their respective motors152,154,156using fixed-frequency pulse width modulation (PWM). Each motor152,154,156is supported on a motor bracket148such that motor shaft152a,154a,156aare rotatably disposed within respective apertures of motor bracket148. As illustrated inFIGS.16and19, motor bracket148rotatably supports three rotatable drive connector sleeves152b,154b,156bthat are keyed to respective motor shafts152a,154a,156aof motors152,154,156. Drive connector sleeves152b,154b,156bnon-rotatably receive proximal ends of respective coupling shaft64a,64b,64cof plate assembly60of shell housing10, when power handle101is disposed within shell housing10. Drive connector sleeves152b,154b,156bare each spring biased away from respective motors152,154,156. Rotation of motor shafts152a,154a,156aby respective motors152,154,156function to drive shafts and/or gear components of Adapter assembly200in order to perform the various operations of handle assembly100. In particular, motors152,154,156of power-pack core assembly106are configured to drive shafts and/or gear components of adapter assembly200in order to selectively extend/retract a trocar member274of a trocar assembly270of adapter assembly200; to, open/close reload400(when an anvil assembly510is connected to trocar member274of trocar assembly270), to fire an annular array of staples of reload400, and to fire an annular knife444of reload400. Motor bracket148also supports an electrical receptacle149. Electrical receptacle149is in electrical connection with main controller circuit board142bby a second ribbon cable142d. Electrical receptacle149defines a plurality of electrical slots for receiving respective electrical contacts or blades extending from pass-through connector66of plate assembly60of shell housing10. In use, when adapter assembly200is mated to handle assembly100, each of coupling shafts64a,64b,64cof plate assembly60of shell housing10of handle assembly100couples with corresponding rotatable connector sleeves218,222,220of adapter assembly200(seeFIG.22). In this regard, the interface between corresponding first coupling shaft64aand first connector sleeve218, the interface between corresponding second coupling shaft64band second connector sleeve222, and the interface between corresponding third coupling shaft64cand third connector sleeve220are keyed such that rotation of each of coupling shafts64a,64b,64cof handle assembly100causes a corresponding rotation of the corresponding connector sleeve218,222,220of adapter assembly200. The mating of coupling shafts64a,64b,64cof handle assembly100with connector sleeves218,222,220of adapter assembly200allows rotational forces to be independently transmitted via each of the three respective connector interfaces. The coupling shafts64a,64b,64cof handle assembly100are configured to be independently rotated by respective motors152,154,156. Since each of coupling shafts64a,64b,64cof handle assembly100has a keyed and/or substantially non-rotatable interface with respective connector sleeves218,222,220of adapter assembly200, when adapter assembly200is coupled to handle assembly100, rotational force(s) are selectively transferred from motors152,154,156of handle assembly100to adapter assembly200. The selective rotation of coupling shaft(s)64a,64b,64cof handle assembly100allows handle assembly100to selectively actuate different functions of reload400. As will be discussed in greater detail below, selective and independent rotation of first coupling shaft64aof handle assembly100corresponds to the selective and independent extending/retracting of trocar member274of adapter assembly200and/or the selective and independent opening/closing of reload400(when anvil assembly510is connected to trocar member274). Also, the selective and independent rotation of third coupling shaft64cof handle assembly100corresponds to the selective and independent firing of an annular array of staples of reload400. Additionally, the selective and independent rotation of second coupling shaft64bof handle assembly100corresponds to the selective and independent firing of an annular knife444of reload400. With reference toFIGS.12-19, power-pack core assembly106further includes a switch assembly170supported within distal half-section110aof inner handle housing110, at a location beneath and in registration with toggle control interface130, the right-side pair of control interfaces132a,132b, and the left-side pair of control interfaces134a,134b. Switch assembly170includes a first set of four push-button switches172a-172darranged around stem30aof toggle control button30of outer shell housing10when power handle101is disposed within outer shell housing10. Switch assembly170also includes a second pair of push-button switches174a,174bdisposed beneath right-side pair of control interfaces132a,132bof distal half-section110aof inner handle housing110when power handle101is disposed within outer shell housing10. Switch assembly170further includes a third pair of push-button switches176a,176bdisposed beneath left-side pair of control interfaces134a,134bof distal half-section110aof inner handle housing110when power handle101is disposed within outer shell housing10. Power-pack core assembly106includes a single right-side push-button switch178adisposed beneath right-side control aperture136aof proximal half-section110bof inner handle housing110, and a single left-side push-button switch178bdisposed beneath left-side control aperture136bof proximal half-section110bof inner handle housing110. Push-button switches178a,178bare supported on controller circuit board142. Push-button switches178a,178bare disposed beneath right-side fire button36aand left-side fire button36bof proximal half-section10bof shell housing10when power handle101is disposed within outer shell housing10. The actuation of push button switch172cof switch assembly170of power handle101, corresponding to a downward actuation of toggle control button30, causes controller circuit board142to provide appropriate signals to motor152to activate, to retract a trocar member274of adapter assembly200and/or to close handle assembly100(e.g., approximate anvil assembly510relative to reload400). The actuation of push button switch172aof switch assembly170of power handle101, corresponding to an upward actuation of toggle control button30, causes controller circuit board142to activate, to advance trocar member274of adapter assembly200and/or to open handle assembly100(e.g., separate anvil assembly510relative to reload400). The actuation of fire switch178aor178bof power handle101, corresponding to an actuation of right-side or left-side control button36a,36b, causes controller circuit board142to provide appropriate signals to motors154and156to activate, as appropriate, to fire staples of reload400, and then to advance (e.g., fire) and retract an annular knife444of reload400. The actuation of switches174a,174b(by right-hand thumb of user) or switches176a,176b(by left-hand thumb of user) of switch assembly170, corresponding to respective actuation of right-side pair of control buttons32a,32bor left-side pair of control button34a,34b, causes controller circuit board142to provide appropriate signals to motor152to activate, to advance or retract trocar member274of adapter assembly200. With reference toFIGS.12and14, power-pack core assembly106of handle assembly100includes a USB connector180supported on main controller circuit board142bof controller circuit board142. USB connector180is accessible through control plate160of power-pack core assembly106. When power handle101is disposed within outer shell housing10, USB connector180is covered by plate62of sterile barrier plate assembly60of shell housing10. As illustrated inFIG.1andFIGS.20-65, handle assembly100is configured for selective connection with adapter assembly200, and, in turn, adapter assembly200is configured for selective connection with reload400. Adapter assembly200is configured to convert a rotation of coupling shaft(s)64a,64b,64cof handle assembly100into axial translation useful for advancing/retracting trocar member274of adapter assembly200, for opening/closing handle assembly100(when anvil assembly510is connected to trocar member274), for firing staples of reload400, and for firing annular knife444of reload400, as illustrated inFIG.22, and as will be described in greater detail below. Adapter assembly200includes a first drive transmitting/converting assembly for interconnecting first coupling shaft64aof handle assembly100and an anvil assembly510, wherein the first drive transmitting/converting assembly converts and transmits a rotation of first coupling shaft64aof handle assembly100to an axial translation of trocar member274of trocar assembly270, and in turn, the anvil assembly510, which is connected to trocar member274, to open/close handle assembly100. Adapter assembly200includes a second drive transmitting/converting assembly for interconnecting third coupling shaft64cof handle assembly100and a second axially translatable drive member of reload400, wherein the second drive transmitting/converting assembly converts and transmits a rotation of third coupling shaft64cof handle assembly100to an axial translation of an outer flexible band assembly255of adapter assembly200, and in turn, a driver adapter432of a staple driver assembly430of reload400to fire staples from a staple cartridge420of reload400and against anvil assembly510. Adapter assembly200includes a third drive transmitting/converting assembly for interconnecting second coupling shaft64bof handle assembly100and a third axially translatable drive member of reload400, wherein the third drive transmitting/converting assembly converts and transmits a rotation of second coupling shaft64bof handle assembly100to an axial translation of an inner flexible band assembly265of adapter assembly200, and in turn, a knife assembly440of reload400to fire annular knife444against anvil assembly510. Turning now toFIGS.20-24, adapter assembly200includes an outer knob housing202and an outer tube206extending from a distal end of knob housing202. Knob housing202and outer tube206are configured and dimensioned to house the components of adapter assembly200. Knob housing202includes a drive coupling assembly210which is configured and adapted to connect to connecting portion108of handle housing102of handle assembly100. Adapter assembly200is configured to convert a rotation of either of first, second or third coupling shafts64a,64b,64c, respectively, of handle assembly100, into axial translations useful for operating trocar assembly270of adapter assembly200, anvil assembly510, and/or staple driver assembly430or knife assembly440of reload400, as will be described in greater detail below. As illustrated inFIGS.57-61, adapter assembly200includes a proximal inner housing member204disposed within knob housing202. Inner housing member204rotatably supports a first rotatable proximal drive shaft212, a second rotatable proximal drive shaft214, and a third rotatable proximal drive shaft216therein. Each proximal drive shaft212,214,216functions as a rotation receiving member to receive rotational forces from respective coupling shafts64a,64cand64bof handle assembly100, as described in greater detail below. As described briefly above, drive coupling assembly210of adapter assembly200is also configured to rotatably support first, second and third connector sleeves218,222and220, respectively, arranged in a common plane or line with one another. Each of connector sleeves218,220,222is configured to mate with respective first, second and third coupling shafts64a,64cand64bof handle assembly100, as described above. Each of connector sleeves218,220,222is further configured to mate with a proximal end of respective first, second and third proximal drive shafts212,214,216of adapter assembly200. Drive coupling assembly210of adapter assembly200also includes, as illustrated inFIGS.26,34,35and40, a first, a second and a third biasing member224,226and228disposed distally of respective first, second and third connector sleeves218,222,220. Each of biasing members224,226and228is disposed about respective first, second and third rotatable proximal drive shaft212,216and214. Biasing members224,226and228act on respective connector sleeves218,222and220to help maintain connector sleeves218,222and220engaged with the distal end of respective coupling shafts64a,64band64cof handle assembly100when adapter assembly200is connected to handle assembly100. In particular, first, second and third biasing members224,226and228function to bias respective connector sleeves218,222and220in a proximal direction. In this manner, during connection of handle assembly100to adapter assembly200, if first, second and or third connector sleeves218,222and/or220is/are misaligned with coupling shafts64a,64band64cof handle assembly100, first, second and/or third biasing member(s)224,226and/or228are compressed. Thus, when handle assembly100is operated, coupling shafts64a,64cand64bof handle assembly100will rotate and first, second and/or third biasing member(s)224,228and/or226will cause respective first, second and/or third connector sleeve(s)218,220and/or222to slide back proximally, effectively connecting coupling shafts64a,64cand64bof handle assembly100to first, second and/or third proximal drive shaft(s)212,214and216of drive coupling assembly210. As briefly mentioned above, adapter assembly200includes a first, a second and a third force/rotation transmitting/converting assembly240,250,260, respectively, disposed within inner housing member204and outer tube206. Each force/rotation transmitting/converting assembly240,250,260is configured and adapted to transmit or convert a rotation of a first, second and third coupling shafts64a,64cand64bof handle assembly100into axial translations to effectuate operation of trocar assembly270of adapter assembly200, and of staple driver assembly430or knife assembly440of reload400. As shown inFIGS.25-28, first force/rotation transmitting/converting assembly240includes first rotatable proximal drive shaft212, as described above, a second rotatable proximal drive shaft281, a rotatable distal drive shaft282, and a coupling member286, each of which are supported within inner housing member204, drive coupling assembly210and/or an outer tube206of adapter assembly200. First force/rotation transmitting/converting assembly240functions to extend/retract trocar member274of trocar assembly270of adapter assembly200, and to open/close handle assembly100(when anvil assembly510is connected to trocar member274). First rotatable proximal drive shaft212includes a non-circular or shaped proximal end portion configured for connection with first connector218which is connected to respective first coupling shaft64aof handle assembly100. First rotatable proximal drive shaft212includes a non-circular recess formed therein which is configured to key with a respective complimentarily shaped proximal end portion281aof second rotatable proximal drive shaft281. Second rotatable proximal drive shaft281includes a distal end portion281bdefining an oversized recess therein which is configured to receive a proximal end portion282aof first rotatable distal drive shaft282. Proximal end portion282aof first rotatable distal drive shaft282is pivotally secured within the recess in distal end281bof second rotatable proximal drive shaft281by a pin283areceived through the oversized recess in distal end portion281bof second rotatable proximal drive shaft281. First rotatable distal drive shaft282includes a proximal end portion282a, and a distal end portion282bwhich is pivotally secured within a recess of coupling member286. Distal end portion282bof first rotatable distal drive shaft282is pivotally secured within a recess in a proximal end of coupling member286by a pin283breceived through the recess in the proximal end portion of coupling member286. Proximal and distal end portions282a,282bof first rotatable distal drive shaft282define oversized openings for receiving pins283a,283b, respectively. Coupling member286includes a proximal end286adefining a recess286cfor receiving distal end portion282bof first rotatable distal drive shaft282, a distal end286bdefining a recess286dfor operably receiving a non-circular stem276con proximal end276aof a drive screw276of trocar assembly270. First force/rotation transmitting/converting assembly240further includes a trocar assembly270removably supported in a distal end of outer tube206. Trocar assembly270includes an outer housing272, a trocar member274slidably disposed within tubular outer housing272, and a drive screw276operably received within trocar member274for axially moving trocar member274relative to tubular housing272. In particular, trocar member274includes a proximal end274ahaving an inner threaded portion which engages a threaded distal portion276bof drive screw276. Trocar member274further includes at least one longitudinally extending flat formed in an outer surface thereof which mates with a corresponding flat formed in tubular housing272thereby inhibiting rotation of trocar member274relative to tubular housing272as drive screw276is rotated. A distal end274bof trocar member274is configured to selectively engage anvil assembly510(FIGS.73-75). Tubular housing272of trocar assembly270is axially and rotationally fixed within outer tube206of adapter assembly200. Tubular housing272defines a pair of radially opposed, and radially oriented openings272awhich are configured and dimensioned to cooperate with a pair of lock pins275cof a trocar assembly release mechanism275. With reference toFIGS.29-33, adapter assembly200includes a support block292fixedly disposed within outer tube206. Support block292is disposed proximal of a connector sleeve290and proximal of a strain sensor320aof a strain gauge assembly320, as described in greater detail below. The pair of lock pins275cextend through support block292and into tubular housing272of trocar assembly270to connect trocar assembly270to adapter assembly200. As illustrated inFIGS.29-33, trocar assembly release mechanism275includes a release button275apivotally supported on support block292and in outer tube206. Release button275ais spring biased to a locked/extended condition. Trocar assembly release mechanism275further includes a spring clip275bconnected to release button275a, wherein spring clip275bincludes a pair of legs that extend through support block292and transversely across trocar assembly270. Each of the pair of legs of spring clip275bextends through a respective lock pin275cwhich is slidably disposed within a respective radial opening272aof tubular housing272and radial opening292aof support block292(seeFIG.31). In use, when release button275ais depressed (e.g., in a radially inward direction,FIG.33), release button275amoves spring clip275btransversely relative to trocar assembly270. As spring clip275bis moved transversely relative to trocar assembly270, the pair of legs of spring clip275btranslate through the pair of lock pins275csuch that a goose-neck in each leg acts to cam and urge the pair of lock pins275cradially outward. Each of the pair of lock pins275cis urged radially outward by a distance sufficient that each of the pair of lock pins275cclears respective opening272aof tubular housing272. With the pair of lock pins275cfree and clear of tubular housing272, trocar assembly270may be axially withdrawn from within the distal end of outer tube206of adapter assembly200. In operation, as first rotatable proximal drive shaft212is rotated, due to a rotation of first connector sleeve218, as a result of the rotation of first coupling shaft64aof handle assembly100, second rotatable distal drive shaft281is caused to be rotated. Rotation of second rotatable distal drive shaft281results in contemporaneous rotation of first rotatable distal drive shaft282. Rotation of first rotatable distal drive shaft282causes contemporaneous rotation of coupling member286, which, in turn, causes contemporaneous rotation of drive screw276of trocar assembly270. As drive screw276is rotated within and relative to trocar member274, engagement of the inner threaded portion of trocar member274with threaded distal portion276bof drive screw276causes axial translation of trocar member274within tubular housing272of trocar assembly270. Specifically, rotation of drive screw276in a first direction causes axial translation of trocar member274in a first direction (e.g., extension of trocar assembly270of handle assembly100), and rotation of drive screw276in a second direction causes axial translation of trocar member274in a second direction (e.g., retraction of trocar assembly270of handle assembly100). When anvil assembly510is connected to trocar member274, as will be described in detail below, the axial translation of trocar member274in the first direction results in an opening of reload400, and the axial translation of trocar member274in the second direction results in a closing of reload400. Forces during an actuation or trocar member274or a closing of reload400may be measured by strain sensor320aof strain gauge assembly320in order to:determine a presence and proper engagement of trocar assembly270in adapter assembly200;determine a presence of anvil assembly510during calibration;determine misalignment of the splines of trocar member274with longitudinally extending ridges416of reload400;determine a re-clamping of a previously tiled anvil assembly510;determine a presence of obstructions during clamping or closing of reload400;determine a presence and connection of anvil assembly510with trocar member274;monitor and control a compression of tissue disposed within reload400;monitor a relaxation of tissue, over time, clamped within reload400;monitor and control a firing of staples from reload400;detect a presence of staples in reload400;monitors forces during a firing and formation of the staples as the staples are being ejected from reload400;optimize formation of the staples (e.g., staple crimp height) as the staples are being ejected from reload400for different indications of tissue;monitor and control a firing of annular knife444of reload400;monitor and control a completion of the firing and cutting procedure; andmonitor a maximum firing force and control the firing and cutting procedure to protect against exceeding a predetermined maximum firing force. In operation, strain sensor320aof strain gauge assembly320of adapter assembly200measures and monitors the retraction of trocar member274, as described above. During the closing of reload400, if and when head assembly512of anvil assembly510contacts tissue, an obstruction, staple cartridge420or the like, a reaction force is exerted on head assembly512which is in a generally distal direction. This distally directed reaction force is communicated from head assembly512to center rod assembly514of anvil assembly510, which in turn is communicated to trocar assembly270. Trocar assembly270then communicates the distally directed reaction force to the pair of pins275cof trocar assembly release mechanism275, which in turn then communicate the reaction force to support block292. Support block292then communicates the distally directed reaction force to strain sensor320aof strain gauge assembly320. Strain sensor320aof strain gauge assembly320is a device configured to measure strain (a dimensionless quantity) on an object that it is adhered to (e.g., support block292), such that, as the object deforms, a metallic foil of the strain sensor320ais also deformed, causing an electrical resistance thereof to change, which change in resistance is then used to calculate loads experienced by trocar assembly270. Strain sensor320aof strain gauge assembly320then communicates signals to main controller circuit board142bof power-pack core assembly106of handle assembly100. Graphics are then displayed on display screen146of power-pack core assembly106of handle assembly100to provide the user with real-time information related to the status of the firing of handle assembly100. With reference toFIGS.34-38, second force/rotation transmitting/converting assembly250of adapter assembly200includes second proximal drive shaft214, as described above, a first coupling shaft251, a planetary gear set252, a staple lead screw253, and a staple driver254, each of which are supported within inner housing member204, drive coupling assembly210and/or an outer tube206of adapter assembly200. Second force/rotation transmitting/converting assembly250functions to fire staples of reload400for formation against anvil assembly510. Second rotatable proximal drive shaft214includes a non-circular or shaped proximal end portion configured for connection with second connector or coupler220which is connected to respective second coupling shaft64cof handle assembly100. Second rotatable proximal drive shaft214further includes a distal end portion214bhaving a spur gear non-rotatably connected thereto. First coupling shaft251of second force/rotation transmitting/converting assembly250includes a proximal end portion251ahaving a spur gear non-rotatably connected thereto, and a distal end portion251bhaving a spur gear non-rotatably connected thereto. The spur gear at the proximal end portion251aof first coupling shaft251is in meshing engagement with the spur gear at the distal end portion214bof the second rotatable proximal drive shaft214. Planetary gear set252of second force/rotation transmitting/converting assembly250includes a first cannulated sun gear252a, a first set of planet gears252b, a ring gear252c, a second set of planet gears252d, and a second cannulated sun gear252e. First sun gear252ais in meshing engagement with the spur gear at the distal end portion251bof first coupling shaft251. The first set of planet gears252bare interposed between, and are in meshing engagement with, first sun gear252aand ring gear252c. The second set of planet gears252dare interposed between, and are in meshing engagement with, second sun gear252eand ring gear252c. Ring gear252cis non-rotatably supported in outer tube206of adapter assembly200. Planetary gear set252of second force/rotation transmitting/converting assembly250includes a washer252fdisposed within ring gear252c, and between the first set of planet gears252band the second set of planet gears252d. The first set of planet gears252bare rotatably supported radially about washer252f, and second sun gear252eis non-rotatably connected to a center of washer252f. Staple lead screw253of second force/rotation transmitting/converting assembly250includes a proximal flange253aand a distal threaded portion253bextending from flange253a. Staple lead screw253defines a lumen253ctherethrough. The second set of planet gears252dare rotatably supported radially about proximal flange253aof staple lead screw253. Staple driver254of second force/rotation transmitting/converting assembly250includes a central threaded lumen254aextending therethrough and is configured and dimensioned to support distal threaded portion253bof staple lead screw253therein. Staple driver254includes a pair of tabs254bprojecting radially from an outer surface thereof, and which are configured for connection to outer flexible band assembly255of adapter assembly200, as will be described in greater detail below. With reference now toFIGS.34,35and43-51, second force/rotation transmitting/converting assembly250of adapter assembly200includes an outer flexible band assembly255secured to staple driver254. Outer flexible band assembly255includes first and second flexible bands255a,255blaterally spaced and connected at proximal ends thereof to a support ring255cand at distal ends thereof to a proximal end of a support base255d. Each of first and second flexible bands255a,255bis attached to support ring255cand support base255d. Outer flexible band assembly255further includes first and second connection extensions255e,255fextending proximally from support ring255c. First and second connection extensions255e,255fare configured to operably connect outer flexible band assembly255to staple driver254of second force/rotation transmitting/converting assembly250. In particular, each of first and second connection extensions255e,255fdefines an opening configured to receive a respective tab254bof staple driver254. Receipt of tabs254bof staple driver254within the openings of respective first and second connection extensions255e,255fsecures outer flexible band assembly255to staple driver254of second force/rotation transmitting/converting assembly250. Support base255dextends distally from flexible bands255a,255band is configured to selectively contact driver adapter432of staple driver assembly430of reload400. Flexible bands255a,255bare fabricated from stainless steel301half hard and are configured to transmit axial pushing forces along a curved path. Second force/rotation transmitting/converting assembly250and outer flexible band assembly255are configured to receive first rotatable proximal drive shaft212, first rotatable distal drive shaft282, and trocar assembly270of first force/rotation transmitting/converting assembly240therethrough. Specifically, first rotatable proximal drive shaft212is non-rotatably connected to second rotatable proximal drive shaft281which in turn is rotatably disposed within and through first cannulated sun gear252aof first planetary gear set252, second cannulated sun gear252eof planetary gear set252, staple lead screw253, and staple driver254. Second force/rotation transmitting/converting assembly250and outer flexible band assembly255are also configured to receive third force/rotation transmitting/converting assembly260therethrough. Specifically, as described below, inner flexible band assembly265is slidably disposed within and through outer flexible band assembly255. First rotatable distal drive shaft282of first force/rotation transmitting/converting assembly240is rotatably disposed within support base255dof outer flexible band assembly255, while trocar member274of trocar assembly270of first force/rotation transmitting/converting assembly240is slidably disposed within support base255dof outer flexible band assembly255. Outer flexible band assembly255is also configured to receive inner flexible band assembly265therethrough. In operation, as second rotatable proximal drive shaft214is rotated due to a rotation of second connector sleeve220, as a result of the rotation of the second coupling shaft64cof handle assembly100, first coupling shaft251is caused to be rotated, which in turn causes first cannulated sun gear252ato rotate. Rotation of first cannulated sun gear252a, results in contemporaneous rotation of the first set of planet gears252b, which in turn causes washer252fto contemporaneously rotate second cannulated sun gear252e. Rotation of second cannulated sun gear252e, results in contemporaneous rotation of the second set of planet gears252d, which in turn causes contemporaneous rotation of staple lead screw253. As staple lead screw253is rotated, staple driver254is caused to be axially translated, which in turn causes outer flexible band assembly255to be axially translated. As outer flexible band assembly255is axially translated, support base255dpresses against driver adapter432of staple driver assembly430of reload400to distally advance driver434and fire staples “S” (FIG.67) of reload400against anvil assembly510for formation of staples “S” in underlying tissue. With reference toFIGS.39-42and45-51, third force/rotation transmitting/converting assembly260of adapter assembly200includes third proximal drive shaft216, as described above, a second coupling shaft261, a planetary gear set262, a knife lead screw263, and a knife driver264, each of which are supported within inner housing member204, drive coupling assembly210and/or an outer tube206of adapter assembly200. Third force/rotation transmitting/converting assembly260functions to fire knife of reload400. Third rotatable proximal drive shaft216includes a non-circular or shaped proximal end portion configured for connection with third connector or coupler222which is connected to respective third coupling shaft64bof handle assembly100. Third rotatable proximal drive shaft216further includes a distal end portion216bhaving a spur gear non-rotatably connected thereto. Second coupling shaft261of third force/rotation transmitting/converting assembly260includes a proximal end portion261ahaving a spur gear non-rotatably connected thereto, and a distal end portion261bhaving a spur gear non-rotatably connected thereto. The spur gear at the proximal end portion261aof second coupling shaft261is in meshing engagement with the spur gear at the distal end portion216bof the third rotatable proximal drive shaft216. Planetary gear set262of third force/rotation transmitting/converting assembly260includes a first cannulated sun gear262a, a first set of planet gears262b, a ring gear262c, a second set of planet gears262d, and a second cannulated sun gear262e. First sun gear262ais non-rotatably supported on a distal end portion of a hollow shaft269. Hollow shaft269includes a spur gear269anon-rotatably supported on a proximal end thereof. Spur gear269aof hollow shaft269is in meshing engagement with the spur gear at the distal end portion261bof second coupling shaft261. The first set of planet gears262bare interposed between, and are in meshing engagement with, first sun gear262aand ring gear262c. The second set of planet gears262dare interposed between, and are in meshing engagement with, second sun gear262eand ring gear262c. Ring gear262cis non-rotatably supported in outer tube206of adapter assembly200. Planetary gear set262of third force/rotation transmitting/converting assembly260includes a washer262fdisposed within ring gear262c, and between the first set of planet gears262band the second set of planet gears262d. The first set of planet gears262bare rotatably supported radially about washer262f, and second sun gear262eis non-rotatably connected to a center of washer262f. Knife lead screw263of second force/rotation transmitting/converting assembly260includes a proximal flange263aand a distal threaded portion263bextending from flange263a. Knife lead screw263defines a lumen263ctherethrough. The second set of planet gears262dare rotatably supported radially about proximal flange263aof knife lead screw263. Knife driver264of second force/rotation transmitting/converting assembly260includes a central threaded lumen264aextending therethrough and is configured and dimensioned to support distal threaded portion263bof knife lead screw263therein. Knife driver264includes a pair of tabs264bprojecting radially from an outer surface thereof, and which are configured for connection to inner flexible band assembly265of adapter assembly200, as will be described in greater detail below. With reference now toFIGS.39-42, third force/rotation transmitting/converting assembly260of adapter assembly200includes an inner flexible band assembly265secured to knife driver264. Inner flexible band assembly265includes first and second flexible bands265a,265blaterally spaced and connected at proximal ends thereof to a support ring265cand at distal ends thereof to a proximal end of a support base265d. Each of first and second flexible bands265a,265bare attached to support ring265cand support base265d. Inner flexible band assembly265is configured to receive first rotatable proximal drive shaft212, first rotatable distal drive shaft282, and trocar assembly270of first force/rotation transmitting/converting assembly240therethrough. Inner flexible band assembly265further includes first and second connection extensions265e,265fextending proximally from support ring265c. First and second connection extensions265e,265fare configured to operably connect inner flexible band assembly265to knife driver264of third force/rotation transmitting/converting assembly260. In particular, each of first and second connection extensions265e,265fdefines an opening configured to receive a respective tab264bof knife driver264. Receipt of tabs264bof knife driver264within the openings of respective first and second connection extensions265e,265fsecures inner flexible band assembly265to knife driver264of third force/rotation transmitting/converting assembly260. Support base265dextends distally from flexible bands265a,265band is configured to connect with knife carrier442of knife assembly440of reload400. Flexible bands265a,265bare fabricated from stainless steel301half hard and are configured to transmit axial pushing forces along a curved path. Third force/rotation transmitting/converting assembly260and inner flexible band assembly265are configured to receive first rotatable proximal drive shaft212, first rotatable distal drive shaft282, and trocar assembly270of first force/rotation transmitting/converting assembly240therethrough. Specifically, first rotatable proximal drive shaft212is rotatably disposed within and through hollow shaft269, first cannulated sun gear262aof first planetary gear set262, second cannulated sun gear262eof planetary gear set262, knife lead screw263, and knife driver264. First rotatable distal drive shaft282of first force/rotation transmitting/converting assembly240is also rotatably disposed within support base265dof inner flexible band assembly265, while trocar member274of trocar assembly270of first force/rotation transmitting/converting assembly240is slidably disposed within support base265dof inner flexible band assembly265. In operation, as third rotatable proximal drive shaft216is rotated due to a rotation of third connector sleeve222, as a result of the rotation of the third coupling shaft64bof handle assembly100, second coupling shaft261is caused to be rotated, which in turn causes hollow shaft269to rotate. Rotation of hollow shaft269results in contemporaneous rotation of the first set of planet gears262b, which in turn causes washer262fto rotate second cannulated sun gear262e. Rotation of second cannulated sun gear262ecauses contemporaneous rotation of the second set of planet gears262d, which in turn causes knife lead screw263to rotate. As knife lead screw263is rotated, knife driver264is caused to be axially translated, which in turn causes inner flexible band assembly265to be axially translated. As inner flexible band assembly265is axially translated, support base265dpresses against knife carrier442of reload400to distally advance knife carrier442and fire annular knife444of reload400against anvil assembly510for cutting of tissue clamped in reload400. Turning now toFIGS.21-24, adapter assembly200includes an outer tube206extending from knob housing202. As mentioned above, outer tube206is configured to support first, second and third force/rotation transmitting/converting assembly240,250,260, respectively. Adapter assembly200further includes a frame assembly230supported in outer tube206. Frame assembly230is configured to support and guide flexible bands255a,255bof outer flexible band assembly255, and flexible bands265a,265bof inner flexible band assembly265, as flexible bands255a,255b,265a,265bare axially translated through outer tube206. Frame assembly230includes first and second proximal spacer members232a,232b, and first and second distal spacer members234a,234b. When secured together, first and second proximal spacer members232a,232bdefine a pair of inner longitudinal slots234cfor slidably receiving first and second flexible bands265a,265bof inner flexible band assembly265and a pair of outer longitudinal slots234dfor slidably receiving first and second flexible bands255a,255bof outer flexible band assembly255. First and second proximal spacer members232a,232bfurther define a longitudinal passage therethrough for receipt of first force/rotation transmitting/converting assembly240and trocar assembly270. First and second distal spacer members234a,234bdefine a pair of inner slots234cfor slidably receiving first and second flexible bands265a,265bof inner flexible band assembly265and a pair of outer slots234dfor slidably receiving first and second flexible bands255a,255bof outer flexible band assembly255. First and second distal spacer members234a,234bfurther define a longitudinal passage therethrough for receipt of first force/rotation transmitting/converting assembly240and trocar assembly270. First and second proximal spacer members232a,232band first and second distal spacer members234a,234bare formed of plastic to reduce friction with flexible bands255a,255bof outer flexible band assembly255, and flexible bands265a,265bof inner flexible band assembly265. With reference now toFIGS.44-50, frame assembly230further includes a seal member235. Seal member235engages outer tube206, inner and outer flexible bands255a,255band265a,265bof respective inner and outer flexible band assemblies255,265and trocar assembly270, and wiring extending therethrough, in a sealing manner. In this manner, seal member235operates to provide a fluid tight seal through between the distal end and the proximal end of outer tube206. Adapter assembly200further includes a connector sleeve290fixedly supported at a distal end of outer tube206. Connector sleeve290is configured to selectively secure securing reload400to adapter assembly200, as will be described in greater detail below. Connector sleeve290is also configured to be disposed about distal ends of outer and inner flexible assemblies255,265and trocar assembly270. In particular, a proximal end of connector sleeve290is received within and securely attached to the distal end of outer tube206and is configured to engage a stain gauge assembly320of adapter assembly200, and a distal end of connector sleeve290is configured to selectively engage a proximal end of reload400. With reference now toFIGS.52-55,60and69, adapter assembly200includes an electrical assembly310disposed therewithin, and configured for electrical connection with and between handle assembly100and reload400. Electrical assembly310serves to allow for calibration and communication information (e.g., identifying information, life-cycle information, system information, force information) to the main controller circuit board142bof power-pack core assembly106via electrical receptacle149of power-pack core assembly106of handle assembly100. Electrical assembly310includes a proximal pin connector assembly312, a proximal harness assembly314in the form of a ribbon cable, a distal harness assembly316in the form of a ribbon cable, a strain gauge assembly320, and a distal electrical connector322. Proximal pin connector assembly312of electrical assembly310is supported within inner housing member204and drive coupling assembly210of knob housing202. Proximal pin connector assembly312includes a plurality of electrical contact blades312asupported on a circuit board312band which enable electrical connection to pass-through connector66of plate assembly60of outer shell housing10of handle assembly100. Proximal harness assembly314is electrically connected to circuit board312bof proximal pin connector assembly312(FIGS.53and54). Strain gauge assembly320is electrically connected to proximal pin connector assembly312via proximal and distal harness assemblies314,316. Strain gauge assembly320includes a strain sensor320asupported in outer tube206of adapter assembly200. Strain sensor320ais electrically connected to distal harness assembly316via a sensor flex cable320b. Strain sensor320adefines a lumen therethrough, through which trocar assembly270extends. As illustrated inFIGS.29-33, trocar assembly270of first force/rotation transmitting/converting assembly240extends through strain sensor320aof strain gauge assembly320. Strain gauge assembly320provides a closed-loop feedback to a firing/clamping load exhibited by first, second and third force/rotation transmitting/converting assembly240,250,260, respectively. Strain sensor320aof strain gauge assembly320is supported in outer tube206and interposed between connector sleeve290and support block292. Support block292includes a raised ledge292b(seeFIG.29) which extends distally therefrom and which is in contact with strain sensor320a. With reference now toFIGS.53-55, electrical assembly310includes, as mentioned above, a distal electrical connector322which is supported in connector sleeve290. Distal electrical connector322is configured to selectively mechanically and electrically connect to chip assembly460of reload400when reload400is connected to adapter assembly200. Distal electrical connector322includes a plug member322a, first and second wires323a,323b, and first and second contact members324a,324belectrically connected to respective first and second wires323a,323b. Plug member322aincludes a pair of arms322b,322csupporting first and second contact members324a,324b, respectively. The pair of arms322b,322care sized and dimensioned to be received within a cavity461aof chip assembly460and about a circuit board assembly464of reload400when reload400is connected to adapter assembly200. First and second contact members324a,324bof distal electrical connector322are configured to engage respective contact members464bof circuit board assembly464of chip assembly460of reload400when reload400is connected to adapter assembly200. With reference now toFIGS.57-65, adapter assembly200includes a rotation assembly330configured to enable rotation of adapter assembly200relative to handle assembly100. Specifically, outer knob housing202and an outer tube206of adapter assembly200are rotatable relative to drive coupling assembly210of adapter assembly200. Rotation assembly330includes a lock button332operably supported on outer knob housing202. As will be described in further detail below, when rotation assembly330is in an unlocked configuration, outer knob housing202and an outer tube206are rotatable along a longitudinal axis of adapter assembly200relative to drive coupling assembly210. When rotation assembly330is in a locked configuration, outer knob housing202and an outer tube206are rotationally secured relative to drive coupling assembly210. In particular, being that outer tube206has a curved profile, rotation of outer knob housing202and an outer tube206about the longitudinal axis of adapter assembly200causes handle assembly100to be positioned in various orientations relative to adapter assembly200in order to provide the clinician with increased flexibility in manipulating the surgical instrument in the target surgical site. Lock button332of rotation assembly330is configured to operatively engage inner housing member204of adapter assembly200. Inner housing member204is a substantially cylindrical member defining a pair of longitudinal openings for receiving at least portions of first and second force/rotation transmitting/converting assemblies240,250therethrough. Inner housing member204includes proximal and distal annular flanges204a,204band further defines proximal and distal outer annular grooves. The proximal annular groove of inner housing member204accommodates an inner annular flange of outer knob housing202to rotatably secure outer knob housing202to inner housing member204. With reference still toFIGS.57-65, distal annular flange204band the distal annular groove of inner housing member204operate in combination with rotation assembly330of adapter assembly200to secure outer knob housing202in fixed rotational orientations relative to inner housing member204. In particular, distal annular flange204bof inner housing member204defines first, second, and third radial cutouts204c,204d,204econfigured to selectively receive a lock shoe334of lock button332of rotation assembly330. The first and third cutouts204c,204eare opposed to one another, and second cutout204dis oriented perpendicular to the first and third cutouts204c,204e. With reference toFIGS.60-61, outer knob housing202has a frustoconical profile including a plurality of ridges configured for operable engagement by a clinician. Outer knob housing202defines a radial opening for operably supporting lock button332. The opening in outer knob housing202is positioned in alignment or registration with the distal annular groove of inner housing member204such that lock button332of rotation assembly330is receivable with the distal annular groove and selectively receivable within each of the first, second, and third cutouts204c,204d,204ein distal annular flange204bof inner housing member204. As mentioned above, rotation assembly330of adapter assembly200includes a lock button332operably supported in an opening of outer knob housing202and configured for actuating rotation assembly330. Rotation assembly330further includes a lock shoe334disposed between outer knob housing202and inner housing member204and axially slidable relative to lock button332and inner housing member204. A biasing member336is interposed between lock button332and lock shoe334to urge lock button332to a locked position, wherein lock shoe334is disposed within one of first, second, and third cutouts204c,204d,204ein distal annular flange204bof inner housing member204. Lock button332is configured for operable engagement by a clinician. Lock button member332defines an angled cam slot332aformed therein for receiving a cam pin or boss334aof lock shoe334. The biasing member336biases lock button332and lock shoe334away from one another, and urges lock shoe334into contact with distal annular flange204bof inner housing member204and into one of first, second, and third cutouts204c,204d,204ein distal annular flange204bwhen lock shoe334is in registration with one of first, second, and third cutouts204c,204d,204e. As mentioned above, lock shoe334is configured to be selectively received within one of the first, second, and third radial cutouts204c,204d,204ein distal annular flange204bof inner housing member204. Specifically, lock shoe334includes or defines a shoulder334aprojecting from a surface thereof for receipt in one of the first, second, and third radial cutouts204c,204d,204ein distal annular flange204bwhen shoulder334aof lock shoe334is in registration with one of the first, second, and third radial cutouts204c,204d,204ein distal annular flange204band lock button332is un-depressed. When shoulder334aof lock shoe334is free of any of the first, second, and third radial cutouts204c,204d,204ein distal annular flange204b(e.g., rotation assembly330is in an unlocked condition), outer knob housing202is free to rotate relative to inner housing member204, and thus adapter assembly200is free to rotate relative to handle assembly100. The operation of rotation assembly330will now be described with continued reference toFIGS.57-65. Referring initially toFIGS.58,59,61and64, rotation assembly330is shown in a locked condition. In particular, in the locked condition, shoulder334aof lock shoe334is received within first cutout204cin distal annular flange204aof inner housing member204. Also, in the locked condition, lock button332of rotation mechanism330is biased radially outward by biasing member336. When lock button332of rotation assembly330is depressed, as indicated by arrow “A” inFIG.64, lock button332moves radially inward against the bias of biasing member336. As lock button332moves radially inward, lock shoe334slides axially in a distal direction, against the bias of biasing member336. The axial sliding of lock shoe334moves shoulder334aof lock shoe334from within the first radial cutout204cof the distal annular flange204bof inner housing member204, thus placing rotation assembly330in an unlocked condition and freeing outer knob housing202to rotate, as indicated by arrow “B” inFIG.62, relative to inner housing member204. Turning now toFIG.65, once rotation assembly330is in the unlocked condition, outer knob housing202may be rotated relative to inner housing member204. The release of lock button332allows biasing member336to bias lock button332to its initial position. Similarly, biasing member336biases lock shoe334to its initial position. When lock shoe334is re-aligned with one of the first, second, and third radial cutouts204c,204d,204eof distal annular flange204bof inner housing member204, as outer knob housing202is rotated relative to inner housing member204, shoulder334aof lock shoe334is free to be received within the respective first, second, and third cutout204c,204d,204eand rotationally locks outer knob housing202relative to inner housing member204and drive coupling assembly210of adapter assembly200. Rotation assembly330may be used throughout the surgical procedure to rotate handle assembly100and adapter assembly200relative to one another. During rotation of outer knob housing202relative to inner housing member204and drive coupling assembly210of adapter assembly200, since proximal drive shafts212,214,216are supported in drive coupling assembly210, and since first coupling shaft251of second force/rotation transmitting/converting assembly250, second coupling shaft261of third force/rotation transmitting/converting assembly260, and second rotatable proximal drive shaft281of first force/rotation transmitting/converting assembly240are supported in inner housing member204, the respective angular orientations of proximal drive shaft212relative to second rotatable proximal drive shaft281, proximal drive shaft216relative to second coupling shaft261, and proximal drive shaft214relative to first coupling shaft251, are changed relative to one another. Adapter assembly200further includes, as seen inFIGS.57-59, an attachment/detachment button342supported thereon. Specifically, button342is supported on drive coupling assembly210of adapter assembly200and is biased by a biasing member344to an un-actuated condition. Button342includes a lip or ledge342aformed therewith that is configured to snap behind a corresponding lip or ledge20a(FIG.18) defined along recess20of connecting portion108of handle housing102of handle assembly100. In use, when adapter assembly200is connected to handle assembly100, lip342aof button342is disposed behind lip108bof connecting portion108of handle housing102of handle assembly100to secure and retain adapter assembly200and handle assembly100with one another. In order to permit disconnection of adapter assembly200and handle assembly100from one another, button342is depressed or actuated, against the bias of biasing member344, to disengage lip342aof button342and lip108bof connecting portion108of handle housing102of handle assembly100. As illustrated inFIGS.1and66-80, reload400is configured for operable connection to adapter assembly200and is configured to fire and form an annular array of surgical staples, and to sever a ring of tissue. Reload400includes a shipping cap assembly (not shown) that is selectively received on a distal end402of reload400and can function to facilitate insertion of reload400into a target surgical site and to maintain staples “S” (FIG.67) within a staple cartridge420of reload400. Shipping cap assembly401also functions to prevent premature advancement of a staple driver assembly430(FIG.66) of reload400and of a knife assembly440(FIG.66) of reload400prior to and during attachment of reload400to adapter assembly200. With reference now toFIGS.66-72, reload400includes a housing410having a proximal end portion410aand a distal end portion410b, a staple cartridge420fixedly secured to distal end portion410bof housing410, a staple driver assembly430operably received within housing410, a knife assembly440operably received within housing410, a bushing member450received within proximal end410aof housing410, and a chip assembly460mounted about bushing member450. Housing410of reload400includes an outer cylindrical portion412and an inner cylindrical portion414. A plurality of ribs (not shown) interconnects outer and inner cylindrical portions412,414. Outer cylindrical portion412and inner cylindrical portion414of reload400are coaxial and define a recess412a(FIG.67) therebetween configured to operably receive staple driver assembly430and knife assembly440. Inner cylindrical portion412of reload400includes a plurality of longitudinally extending ridges416(FIG.67) projecting from an inner surface thereof and configured for radially aligning (e.g., clocking) anvil assembly510with reload400during a stapling procedure. As will be described in further detail below, proximal ends416aof longitudinal ridges416are configured to facilitate selective securement of shipping cap assembly401with reload400. An annular ridge418(FIG.67) is formed on an outer surface of inner cylindrical portion412and is configured to assist in maintaining knife assembly440in a retracted position. Staple cartridge420of reload400is fixedly secured on distal end410bof housing410and includes a plurality of staple pockets421formed therein which are configured to selectively retain staples “S”. With continued reference toFIGS.66-72, staple driver assembly430of reload400includes a driver adapter432and a driver434. A proximal end432aof driver adapter432is configured for selective contact and abutment with support base255dof outer flexible band assembly255of second force/rotation transmitting/converting assembly250of adapter assembly200. In operation, during distal advancement of outer flexible band assembly255, as described above, support base255dof outer flexible band assembly255contacts proximal end432aof driver adapter432to advance driver adapter432and driver434from a first or proximal position to a second or distal position. Driver434includes a plurality of driver members436aligned with staple pockets421of staple cartridge420for contact with staples “S”. Accordingly, advancement of driver434relative to staple cartridge420causes ejection of the staples “S” from staple cartridge420. Still referring toFIGS.66-72, knife assembly440of reload400includes a knife carrier442and a circular knife444secured about a distal end442bof knife carrier442. A proximal end442aof knife carrier442is configured for operable connection with support base265dof inner flexible band assembly265of third force/rotation transmitting/converting assembly260of adapter assembly200. In operation, during distal advancement of inner flexible band assembly265, as described above, support base265dof inner flexible band assembly265connects with proximal end442aof knife carrier442to advance knife carrier442and circular knife444from a first or proximal position to a second or advanced position to cause the cutting of tissue disposed between staple cartridge420and anvil assembly510. Distal end452bof bushing member450is secured within a proximal end414aof inner cylindrical portion414of housing410by a plurality of ridges452cformed on distal end452bof bushing member450. Chip assembly460includes a housing461from which annular flange462extends. Annular flange462extends perpendicular to a longitudinal axis of housing461. Annular flange462is configured to be received about a distal end452bof bushing member450. Chip assembly460includes a circuit board assembly464secured within a cavity461aof housing461. Circuit board assembly464includes a circuit board464a, a pair of contact members464band a chip464c. A first end of circuit board464asupports chip464c, and a second end of circuit board464asupports first and second contact members464b. Chip464cis a writable/erasable memory chip. Chip464cincludes the following stored information: lot number, staple size, lumen size, fire count, manufacturing stroke offsets, excessive force index, shipping cap assembly presence, and demonstration modes. Chip464cincludes write capabilities which allow handle assembly100to encode to chip464cthat reload400has been used to prevent reuse of an empty, spent or fired reload. Proximal end410aof housing410is configured for selective connection to connector sleeve290of adapter assembly200. Specifically, outer cylindrical portion412of housing410terminates in a proximal cylindrical flange412ahaving an inner diameter which is larger than a diameter of a distal end portion290aof connector sleeve290of adapter assembly200. Further, proximal end432aof driver adapter432has an outer diameter which is smaller than the diameter of distal end portion290aof connector sleeve290. Reload400includes a compressible release ring413supported on flange412aof outer cylindrical portion412of housing410. Release ring413has a substantially ovoid profile including a relative long axis and a relative short axis. In operation, when radially inward directed forces act along the long axis of release ring413(as indicated by arrows “A1” ofFIG.70), release ring413flexes radially outwardly along the short axis thereof (as indicated by arrows “A2” ofFIG.70). Release ring413includes a ramp feature413aprojecting radially inwardly and located substantially along the short axis of release ring413. Ramp feature413aof release ring413extends through a window412bdefined in flange412aof outer cylindrical portion412of housing410. Ramp feature413aof release ring413projects sufficiently radially inwardly so as to be selectively received in a window290bdefined in distal end portion290aof connector sleeve290. Reload400includes a retaining ring415connected to outer cylindrical portion412of housing410and configured to help retain release ring413on outer cylindrical portion412of housing410. For radial alignment and clocking of reload400with adapter assembly200, reload400includes a longitudinally extending rib412cprojecting radially inwardly from outer cylindrical portion412of housing410which is configured for slidable receipt in a longitudinally extending slot290cdefined in distal end portion290aof connector sleeve290. To connect reload400with adapter assembly200, rib412cof reload400is radially aligned with longitudinally extending slot290cof connector sleeve290of adapter assembly200. reload400and adapter assembly200are then axially approximated towards one another until distal end portion290aof connector sleeve290is received within flange412aof outer cylindrical portion412of housing410and until ramp feature413aof release ring413is received in window290bof connector sleeve290. reload400and adapter assembly200are thus locked together. When reload400is connected with adapter assembly200, distal electrical connector322of adapter assembly200is mechanically and electrically connected to chip assembly460of reload400. To disconnect reload400and adapter assembly200from one another, release ring413is squeezed along the long axis thereof (in the direction of arrows “A1”) to thereby remove ramp feature413aof release ring413from within window290bof connector sleeve290, and thus allowing reload400and adapter assembly200to be axially separated from one another. Referring now toFIGS.71-75, an anvil assembly510is provided and is configured for selective connection to trocar member274of adapter assembly200and for cooperation with reload400. Anvil assembly510includes a head assembly512and a center rod assembly514. Head assembly512includes a post516, a housing518, a cutting ring522, a cutting ring cover523, an anvil plate524, a spacer or washer525, a cam latch member526, and a retainer member527. Post516is centrally positioned within housing518. With reference still toFIGS.73-75, anvil plate524is supported in an outer annular recess528of housing518and includes a plurality of staple pockets530formed therein and configured to receive and form staples. Cutting ring522includes a central opening which is positioned about post516within an inner annular recess of housing518between post516and outer annular recess528. Cutting ring522is formed from polyethylene. Cutting ring cover523is secured to an outwardly facing or proximal surface of cutting ring522. Retainer member527is positioned in the inner annular recess between cutting ring522and a back wall of housing518. Retainer member527is annular and includes a plurality of deformable tabs which engage a rear surface of cutting ring522. Retainer member527prevents cutting ring522from moving or being pushed into the inner annular recess of housing518until a predetermined force sufficient to deform the tabs has been applied to cutting ring522. When the predetermined force is reached, e.g., during cutting of tissue, cutting ring522is urged into the inner annular recess536and compresses the retainer members. Turning back toFIG.75, anvil center rod assembly514includes a center rod552, a plunger554and a plunger spring556. A first end of center rod552includes a pair of arms159which define a cavity159a. A pivot member562is provided to pivotally secure post516to center rod552such that anvil head assembly512is pivotally mounted to anvil center rod assembly514. Cam latch member526is pivotally mounted within a transverse slot of post516of housing518and about pivot member562. Cam latch member526has an outer cam profile which permits plunger554to move forward as cam latch member526rotates in a clockwise direction, and permits plunger554to be retracted as cam latch member rotates in a counter-clockwise direction. Plunger554is slidably positioned in a bore formed in the first end of center rod552. Plunger554includes an engagement finger which is offset from the pivot axis of anvil head assembly512and biased into engagement with an edge of cam latch526. Engagement of the finger of plunger554with the edge of cam latch526presses a leading portion of the edge of cam latch526against an inner periphery of cutting ring522to urge anvil head assembly512to an operative or non-tilted position on center rod552. Anvil head assembly512may be tilted relative to anvil center rod assembly514in a pre-fired tilted position. Tilting of anvil head assembly512relative to anvil center rod assembly514causes the body portion of cam latch member526to engage a finger166of plunger554. As cam latch member526rotates with the tilting of anvil head assembly512, plunger554is retracted with the bore of anvil center rod assembly514, thereby compressing spring556. In this manner, finger566of plunger554is distally biased against the body portion of cam latch member526. With reference toFIGS.74-75, a second end of center rod552includes a bore580defined by a plurality of flexible arms582. The proximal end of each of the flexible arms582includes an internal shoulder dimensioned to releasably engage a shoulder of trocar274of trocar assembly270of adapter assembly200to secure anvil assembly510to adapter assembly200. A plurality of splines586are formed about center rod552. Splines586function to align and/or clock anvil assembly510with staple cartridge420of reload400. With reference now toFIGS.76-81, reload400is configured to selective optional connection with an external irrigation source via an irrigation tube590. Irrigation tube590is configured to deliver air or saline to the anastomosis site for the purpose of leak testing, for improved insertion or for insulflating the rectal stump. Irrigation tube590terminates at a proximal end590athereof with a proximal luer fitting591configured to connect to a syringe (not shown), and at a distal end590bwith a distal fitting592configured to selectively snap-fit connect to a port410cof housing410of reload400. Distal fitting592includes a pair of resilient fingers592aconfigured to engage respective shoulders410ddefined in port410cof housing410. With reference toFIG.89, a schematic diagram of the power handle101, the circular adapter assembly200, and the reload400, is shown. For brevity, only one of the motors152,154,156is shown, namely, motor152. The motor152is coupled to the battery144. In embodiments, the motor152may be coupled to any suitable power source configured to provide electrical energy to the motor152, such as an AC/DC transformer. The battery144and the motor152are coupled to the motor controller circuit board142ahaving a motor controller143which controls the operation of the motor152including the flow of electrical energy from the battery144to the motor152. The main controller circuit board142b(FIGS.12and13) includes a main controller147, which controls the power handle101. The motor controller143includes a plurality of sensors408a,408b, . . .408nconfigured to measure operational states of the motor152and the battery144. The sensors408a-nmay include voltage sensors, current sensors, temperature sensors, telemetry sensors, optical sensors, and combinations thereof. The sensors408a-408nmay measure voltage, current, and other electrical properties of the electrical energy supplied by the battery144. The sensors408a-408nmay also measure angular velocity (e.g., rotational speed) as revolutions per minute (RPM), torque, temperature, current draw, and other operational properties of the motor152. Angular velocity may be determined by measuring the rotation of the motor152or a drive shaft (not shown) coupled thereto and rotatable by the motor152. Position of various axially movable drive shafts may also be determined by using various linear sensors disposed in or in proximity to the shafts or extrapolated from the RPM measurements. In embodiments, torque may be calculated based on the regulated current draw of the motor152at a constant RPM. In further embodiments, the motor controller143and/or the main controller147may measure time and process the above-described values as a function of time, including integration and/or differentiation, e.g., to determine the rate of change in the measured values. The main controller147is also configured to determine distance traveled of various components of the circular adapter assembly200and/or the reload400by counting revolutions of the motors152,154, and156. The motor controller143is coupled to the main controller147, which includes a plurality of inputs and outputs for interfacing with the motor controller143. In particular, the main controller147receives measured sensor signals from the motor controller143regarding operational status of the motor152and the battery144and, in turn, outputs control signals to the motor controller143to control the operation of the motor152based on the sensor readings and specific algorithm instructions, which are discussed in more detail below. The main controller147is also configured to accept a plurality of user inputs from a user interface (e.g., switches, buttons, touch screen, etc. coupled to the main controller147). The main controller147is also coupled to a memory141that is disposed on the main controller circuit board142b. The memory141may include volatile (e.g., RAM) and non-volatile storage configured to store data, including software instructions for operating the power handle101. The main controller147is also coupled to the strain gauge320of the circular adapter assembly200using a wired or a wireless connection and is configured to receive strain measurements from the strain gauge320which are used during operation of the power handle101. The reload400includes a storage device405(e.g., chip464c). The circular adapter assembly200also includes a storage device407. The storage devices405and407include non-volatile storage medium (e.g., EEPROM) that is configured to store any data pertaining to the reload400and the circular adapter assembly200, respectively, including but not limited to, usage count, identification information, model number, serial number, staple size, stroke length, maximum actuation force, minimum actuation force, factory calibration data, and the like. In embodiments, the data may be encrypted and is only decryptable by devices (e.g., main controller147) have appropriate keys. The data may also be used by the main controller147to authenticate the circular adapter assembly200and/or the reload400. The storage devices405and407may be configured in read only or read/write modes, allowing the main controller147to read as well as write data onto the storage device405and407. Operation of the handle assembly100, the circular adapter assembly200, and the reload400is described below with reference toFIGS.82A-F, which shows a flow chart of the operation process. With particular reference toFIG.82A, the power handle101is removed from a charger (not shown) and is activated. The power handle101performs a self-check upon activation and if the self-check passes, the power handle101displays an animation on the display screen146illustrating how the power handle101should be inserted into shell housing10. After the power handle101is inserted into the shell housing10, the power handle101verifies that it is properly inserted into the shell housing10by establishing communications with the electrical connector66of the shell housing10, which has a chip (not shown) disposed therein. The chip within the electrical connector66stores a usage counter which the power handle101uses to confirm that the shell housing10has not been previously used. The data (e.g., usage count) stored on the chip is encrypted and is authenticated by the power handle101prior to determining whether the usage count stored on the chip exceeds the threshold (e.g., if the shell housing10has been previously used). With reference toFIG.82B, after the power handle101is enclosed within the shell housing10to form handle assembly100, adapter assembly200is coupled to handle assembly100. After attachment of circular adapter assembly200, handle assembly100initially verifies that circular adapter assembly200is coupled thereto by establishing communications with the storage device407of the circular adapter assembly200and authenticates circular adapter assembly200. The data (e.g., usage count) stored on the storage device407is encrypted and is authenticated by the power handle101prior to determining whether the usage count stored on the storage device407exceeds the threshold (e.g., if the adapter assembly200has been previously used). Power handle101then performs verification checks (e.g., end of life checks, trocar member274missing, etc.) and calibrates circular adapter assembly200after the handle assembly100confirms that the trocar member274is attached. After circular adapter assembly200is calibrated, an unused reload400, with the shipping cap assembly401, is coupled to circular adapter assembly200. The handle assembly100verifies that circular reload400is attached to circular adapter assembly200by establishing communications with the storage device405of circular reload400. With reference toFIG.82C, power handle101also authenticates the storage device405and confirms that circular reload400has not been previously fired by checking the usage count. The usage count is adjusted and encoded by handle assembly100after use of circular reload400. If circular reload400has been previously used, handle assembly100displays an error indicating the same on the display screen146. The power handle101also performs calibration with the reload400attached to the circular adapter assembly200to determine a starting hard stop position. The main controller147calculates the distance travelled by the motors152,154,156to determine the hard stop. The main controller147also utilizes the traveled distance during calibration to confirm that the reload400is unused. Thus, if the traveled distance is determined to be above a predetermined hard stop threshold, then the main controller147confirms that the staples were previously ejected from the reload400and marks the reload400as used, if the reload400was not properly marked before. Once the anvil assembly510is attached, the main controller147performs another calibration. With continued reference toFIG.82C, upon attaching circular reload400and confirming that circular reload400is unused and has been authenticated, handle assembly100prompts the user to eject the shipping cap assembly401by prompting the user to press up on the toggle control button30. The prompt is displayed as an animation on the display screen146with a flashing arrow pointing toward the toggle control button30. The user depresses the upper portion of the toggle control button30, which activates an automatic extension (and retraction) of trocar member274until the shipping cap assembly401is ejected, at which point the shipping cap ejection process is complete and the handle assembly100is now ready for use. In embodiments, the circular adapter assembly200also operates with reloads400having disposable trans-anal/abdominal introducers. Once the reload400with the introducer is attached, handle assembly100shows a ready screen. This allows the user to insert circular adapter assembly200along with the reload400more easily through intra-abdominal incisions. Thus, when the toggle control button30is pressed, a prompt for ejecting the introducer is displayed, which is similar to the animation for ejecting the shipping cap assembly401. The user depresses the upper portion of the toggle control button30, which activates an automatic extension (and retraction) of the trocar member274until the introducer is ejected, at which point the introducer ejection process is complete. With continued reference toFIG.82C, after the shipping cap assembly401or the introducer is removed, the user commences a surgical procedure which includes preparing the target tissue area and positioning circular adapter assembly200within the colorectal or upper gastrointestinal region or until trocar member274extends sufficiently to permit piercing of tissue. The user presses the toggle control button30to extend the trocar member274until it pierces tissue. While the trocar member274is extending, an animation illustrating the extension process is displayed on the display screen146. In addition, distance traveled by the trocar member274is shown as a scale and the direction of the movement of the trocar member274is shown via an arrow. The trocar member274is extended until it reaches the maximum extension distance which is indicated on the display screen146. With reference toFIGS.82C-Dand86, which shows a flow chart of the clamping process, after extension of the trocar member274, the anvil assembly510(already positioned by surgeon) is attached to the trocar member274and the user begins the clamping process on the tissue interposed between circular reload400and the anvil assembly510by pressing on the bottom of the toggle control button30. The clamping process is also shown as an animation on the display screen146, but as a reverse of the animation of the extension of the trocar member274, e.g., an arrow is highlighted illustrating the retraction direction. During clamping, the anvil assembly510is retracted toward the circular reload400until reaching a fully compressed position, namely position of the anvil assembly510at which the tissue is fully compressed between the anvil assembly510and the reload400. Fully compressed distance varies for each of the different types of reloads (e.g., the distance is about 29 mm for 25 mm reloads). While clamping, the strain gauge assembly320continuously provides measurements to the main controller on the force imparted on the first rotation transmitting assembly240as it moves the anvil assembly510. With reference toFIG.83, which schematically illustrates the travel distance and speed of the anvil assembly510as it is retracted by the first motor152, the anvil assembly510is initially retracted from a full open position marker600at a first speed for a first segment from the full open position marker600to a first distance marker602. Thereafter, the anvil assembly510traverses a second distance from the first distance marker602to a second distance marker604at the second speed, which is slower than the first speed. As the anvil assembly510is traversing the second segment, the main controller147continuously verifies whether the measured force is within predefined parameters to determine if the measured force exceeds a high force threshold limit prior to reaching a starting compression distance (FIGS.83and86). This measurement is used to detect misalignment of the splines586of trocar member274with longitudinally extending ridges416of the reload400. If the force is higher than the high force threshold, then the power handle101temporarily reverses the rotation transmitting assembly240to retract the anvil assembly in an attempt to correct the misalignment of the splines586. The main controller147then reattempts to continue clamping until a third distance marker604is reached. If the third distance marker604is not reached within a predetermined period of time, the main controller147then issues an error, including an alarm on the display screen146prompting the user to inspect the anvil assembly510. After inspection and clearance of any obstruction, the user may then restart the clamping process. Once the anvil assembly510reaches the third distance marker604at the end of the second segment, the power handle101performs a rotation verification to check position of the anvil assembly510. Then the main controller commences a controlled tissue compression (“CTC”) algorithm which varies the clamping speed during tissue compression without exceeding a target compression force. The CTC accounts for slow-changing and rapid-changing forces imparted on the tissue during compression with a second-order predictive force filter. As the predicted force approaches the target force, the clamping speed is slowed to prevent over-shoot. When the measured force reaches the target force and the clamp gap has not yet been achieved, clamping is stopped to allow for tissue relaxation. During tissue relaxation, after the measured force falls below the target clamping force, the CTC recommences. The force exerted on tissue is derived from the strain measurements by the main controller147from the strain gauge assembly320. During CTC, the user continues to press down on the toggle control button30to continue operation of handle assembly100. The third distance marker604, at which the controller commences the CTC, corresponds to the distance at which the anvil assembly510begins to compress the tissue against the staple guide of the circular reload400for the remainder of the clamping process. CTC controls the movement of the anvil assembly510during a third segment, from the third distance marker604to a fourth distance marker606, which corresponds to the fully compressed position of the anvil assembly510. CTC continues until the anvil assembly510reaches the fourth distance marker606. During clamping, if no forces are detected, the handle assembly100identifies that the anvil assembly510is missing and the handle assembly100issues an error. The CTC is run for a predetermined time period, namely, a first time period, and an optional second time period. During execution of the CTC, the main controller monitors force based on strain as measured by the strain gauge assembly320that is imparted on the first rotation transmitting assembly240as it moves the anvil assembly510until the measured force approaches the target clamping force. During execution of the CTC, the main controller147determines whether the measured forces approaches the target clamping force by calculating a predicted clamping force using a second-order predictive filter. Target clamping force may be any suitable threshold from about 100 pounds to about 200 pounds, in embodiments, the target clamping force may be approximately 150 pounds. The CTC calculates a predicted clamping force and compares it to the target clamping force. The main controller samples a plurality of strain gauge values at predetermined frequency (e.g., every 1 millisecond) during a predetermined sampling time period. The main controller147then uses a first plurality of strain gauge samples obtained during the sampling time period to calculate a filtered strain gauge value. The main controller147stores a plurality of filtered strain gauge values and uses three strain gauge samples to predict the target clamping force. In particular, the main controller147initially calculates a first difference between the first two (e.g., first and second) filtered strain gauge values, which provides a first-order comparison. More specifically, the main controller147then calculates a second difference between subsequent two filtered strain gauge values (e.g., second and third values). In embodiments, the subsequent filtered strain gauge values may be any other subsequent values, rather than encompassing the second value used to calculate the first difference. The first difference is then divided by the second difference, to obtain a percentage of the difference. The main controller determines the target clamping force based on a predicted strain change, which is calculated by multiplying the first difference by the percentage of the difference and a value representing future periods of strain extrapolation. The predicted strain change is then added to the current filtered strain gauge value to determine a predicted strain value, which corresponds to the predicted clamping force. If the predicted clamping force is above the target force, the PWM voltage driving the motor152, which is driving the first rotation transmitting assembly240is set to zero. The force is continued to be monitored, and once the force drops below a target threshold, the speed of the motor152is set to an updated speed to continue the clamping process. This process repeats until the fourth distance marker606is reached. The target speed is calculated by the main controller147based on a strain ratio. The strain ratio is calculated by subtracting the predicated strain value from the target clamping force and dividing the difference by the target clamping force. The strain ratio is then used to determine a speed offset by multiplying a difference between maximum and minimum speeds of the motor152by the strain ratio. The speed offset is then added to the minimum speed of the motor152to determine the target speed. The target speed is used to control the motor152in response to the motor deviating by a predetermined amount from currently set speed (e.g., if the motor152deviates by about 50 revolutions per minute). In addition, the motor152is set to a newly calculated target speed, if the current speed of the motor152is zero, e.g., following the predicted clamping force approaching the target force. This allows for varying the speed of the motor152while maintaining the desired force on the tissue during clamping. The target clamping force is fixed for the first time period. When thick tissue is encountered, the clamp gap may not be attained within the first time period (e.g., reaching the fourth distance marker606), clamping is stopped and the operator is notified via the display screen. If the operator chooses to continue the clamping operation, CTC continues to operate for the second time period, during which the target clamping force is incremented until the maximum force is reached. During the second period, clamping movement distance is monitored to determine if the anvil assembly510is moved in response to incremental force increases. Thereafter, the clamp distance is periodically monitored for any minimal movement. If no minimal movement is detected, the target force is dynamically incremented by a proportional amount based on a difference between the current clamp position and the fourth distance marker606. If a maximum force, which is higher than the target clamping force, is detected, all clamping is stopped. In addition, if clamping is not achieved within the second time period, then the CTC issues an alarm. This may include instructing the user on the display screen146to check the clamp site for obstructions. If none are found, the user may continue the clamping process. If the clamping is not complete, e.g., second time period expires and/or the maximum force limit is reached, another alarm is triggered, instructing the user to check tissue thickness and to use a larger reload400to restart the clamping process. With reference toFIGS.82C-Dand86, once CTC is commenced, the display screen146displays a CTC user interface after the main controller147confirms that the anvil assembly510is present based on detection of a minimum force. In particular, the distance scale on the display screen146is replaced with a gauge illustrating the force being imparted on the tissue, and the trocar is replaced with the anvil and tissue being compressed. Also displayed is the progress of the clamping until the fourth distance marker606is reached. Thus, as the anvil assembly510is being moved to compress the tissue under the CTC, the gauge, the anvil animation, and the distance traveled by the anvil assembly510are updated continuously to provide real time feedback regarding the CTC progress. During CTC, the strain gauge assembly320continuously provides measurements to the main controller on the force imparted on the first rotation transmitting assembly240as it moves the anvil assembly510. The force measured by the strain gauge assembly320is represented by the gauge on the display screen146, which is separated into three zones, zone1shows the force from 0% to 50% of the target clamp force, zone2shows the force from 51% to 100%, and zone3shows the maximum force above the target clamp force. High force caution graphic is displayed on screen for zone3, the user is required to perform a second activation of the toggle to confirm clamping despite zone3high forces. The user can then press the toggle control button30to re-clamp, which would move the anvil assembly510until the force reaches the maximum force limit of zone3. This allows for further compression of the tissue in certain circumstances where the user deems it necessary, e.g., based on tissue thickness. Once the CTC algorithm is complete and tissue is compressed, handle assembly100activates an LED and issues a tone indicating the same and the CTC screen indicating 100% compression is continuously displayed on the display screen146until the stapling sequence is started. A pre-fire calibration is performed prior to commencement of the stapling sequence. With reference toFIGS.82D and87A-B, to initiate stapling sequence, the user presses one of the safety buttons36aor36bof the power handle101, which acts as a safety and arms the toggle control button30, allowing it to commence stapling. Upon activation of the safety button36aor36b, a second rotation verification calibration check is performed. The display screen146transitions to the stapling sequence display, which includes a circle illustrating an animated view of a circular anastomosis, a progress bar, and a staple icon. The stapling sequence screen is displayed until user initiates the stapling sequence, exits the stapling sequence, or unclamps. At the start of the stapling sequence, the LED begins to flash and an audio tone is played. The LED continues to flash throughout the duration of the stapling and cutting sequences. To commence the stapling sequence, the user presses down on the toggle control button30, which moves the second rotation transmitting assembly250to convert rotation to linear motion and to eject and form staples from circular reload400. In particular, during the firing sequence, the second motor152advances the driver434using the second rotation transmitting assembly250. The force imparted on the second rotation transmitting assembly250is monitored by the strain gauge assembly320. The process is deemed complete once the second rotation transmitting assembly250reaches a hard stop corresponding to a force threshold and detected by the strain gauge assembly320. This indicates that the staples have been successfully ejected and deformed against the anvil assembly510. With reference toFIG.84, which schematically illustrates the travel distance and speed of the second motor154as it advances the driver434, driver434is initially advanced from a first position marker608(e.g., hardstop) at a first speed for a first segment from the first distance marker608to a second distance marker610. From the second distance marker610, the driver434is advanced at a second speed, slower than the first speed, until it reaches a third distance marker612, to eject the staples. During the first segment, the second motor154advances the driver434until the driver434contacts the staples to commence firing. The main controller147also writes to the storage devices405and407of the reload400and the circular adapter assembly200. In particular, main controller147marks the reload400as “used” in the storage device405and increments the usage count in the storage device407of the circular adapter assembly200. After reaching the second distance marker610, the second motor154is operated at the second, slower speed to eject the staples from the reload400. With reference toFIG.87B, during the second segment, as the staples are ejected from the reload400to staple tissue, the main controller147continually monitors the strain measured by the strain gauge assembly320and determines whether the force corresponding to the measured strain is between a minimum stapling force and a maximum stapling force. The stapling force range may be stored in the storage device405of the reload400and used by the main controller147during the stapling sequence. Determination whether the measured force is below the minimum stapling force is used to verify that the staples are present in the reload400. In addition, a low force may be also indicative of a failure of the strain gauge320. If the measured force is below the minimum stapling force, then the main controller147signals the second motor154to retract the driver434to the second distance marker610. The main controller147also displays a sequence on the display146instructing the user the steps to exit stapling sequence and retract the anvil assembly510. After removing the anvil assembly510, the user may replace the circular adapter assembly200and the reload400and restart the stapling process. If the measured force is above the maximum stapling force, which may be about 500 lbs., the main controller147stops the second motor154and displays a sequence on the display146instructing the user the steps to exit the stapling sequence. However, the user may still continue the stapling process without force limit detection by pressing on toggle control button30. The main controller147determines that the stapling process is completed successfully, if the second motor154reached a third distance marker612associated with stapled tissue and during this movement the measured strain was within the minimum and maximum stapling force limits. Thereafter, the second motor154retracts the driver434to a fourth distance marker614to release pressure on the tissue and subsequently to the second distance marker610prior to starting the cutting sequence. The main controller147is also configured to account for band compression of outer flexible band assembly255during the stapling process which may result in a non-linear relationship between motor position as determined by the main controller147and position of components of the circular adapter assembly200. The main controller147is configured to resolve the discrepancy between the calculated position of the motors152,154,156and the actual position of the components of the circular adapter assembly200using a second order mapping of force changes that result in the discrepancies. The force changes are based on the strain measurements from the strain gauge assembly320. In particular, the main controller147maintains a count of lost turns by the motors152,154,156, namely, turns that did not result in movement of the components of the circular adapter assembly200, e.g., due to compression, based on the force imparted on the components of the circular adapter assembly200. The main controller147accumulates the total lost turns each time the imparted force changes by a predetermined amount, e.g., about 5 lbs. The motor position is then adjusted by the total accumulated lost-turns value to determine whether the target position has been attained. With reference toFIG.82D, progress of staple firing is illustrated by an animation of the anastomosis, the firing progress bar, and staple formation. In particular, the animation illustrates staple legs penetrating tissue and then forming to create concentric staple lines. Once the stapling sequence is complete, the outer circumference is displayed in green. The staple icon also shows initially unformed staples, and then shows the legs of the staples being curled inward. The progress bar is separated into two segments, the first segment being indicative of the stapling process and the second segment being indicative of the cutting process. Thus, as the stapling sequence is ongoing the progress bar continues to fill until it reaches its midpoint. With reference toFIGS.82E and88A-B, after the stapling sequence is complete, the power handle101automatically commences the cutting sequence. During the cutting sequence, the third motor154advances the knife assembly440using the third rotation transmitting assembly260. The force imparted on the third rotation transmitting assembly260is monitored by the strain gauge assembly320. The process is deemed complete once the third rotation transmitting assembly260reaches a hard stop corresponding to a force threshold and detected by the strain gauge assembly320or a maximum position is reached. This indicates that the knife assembly320has cut through the stapled tissue. With reference toFIG.85, which schematically illustrates the travel distance and speed of the third motor156as it advances the knife assembly440. The knife assembly440is initially advanced from a first position marker616at a first speed for a first segment from the first distance marker616until a second distance marker618. From the second distance marker618, the knife assembly440is advanced at a second speed, slower than the first speed, until it reaches a third distance marker620, to cut the stapled tissue. During the first segment, the third motor156advances the knife assembly440until the knife assembly440contacts the stapled tissue. After reaching the second distance marker618, the third motor154is operated at the second, slower speed to cut the stapled tissue. With reference toFIGS.88A-B, during the second segment, as the knife assembly440is advanced to cut tissue, the main controller147continually monitors the strain measured by the strain gauge assembly320and determines whether the force corresponding to the measured strain is between a target cutting force and a maximum cutting force. The target cutting force and the maximum cutting force may be stored in the storage device405of the reload400and used by the main controller147during cutting sequence. If the target cutting force is not reached during the cutting sequence, which is indicative of improper cutting, then the main controller147signals the third motor156retract the knife assembly440allowing the user to open the reload400and abort the cutting sequence. The main controller147also displays a sequence on the display146indicating to the user the steps to exit the cutting sequence and retract the anvil assembly510. After removing the anvil assembly510, the user may replace the circular adapter assembly200and the reload400and restart the stapling process. If the measured force is above the maximum cutting force, the main controller147stops the third motor156and displays a sequence on the display146instructing the user to exit the cutting sequence. The main controller147determines that the stapling process is completed successfully, if the knife assembly440being moved by the third motor156reached a third distance marker620associated with cut tissue and during this movement the measured strain was within the target and maximum cutting force limits. Thereafter, the third motor154retracts the knife assembly440back to the first distance marker616. Each of the distance markers600-620are stored in the memory141and/or the storage device405and are used by the main controller147to control the operation of the power handle101to actuate various components of the circular adapter assembly200based thereon. As noted above the distance markers600-620may be different for different type of reloads accounting for variations in staple size, diameter of the reload, etc. In addition, the distance markers600-620are set from the hard stop as determined during the calibration process described above. With reference toFIG.82E, the cutting sequence is illustrated by the same user interface, except the staple icon is grayed out and a knife icon is highlighted. During the cutting sequence, the knife icon is animated with motion and the progress bar moves from its midpoint to the right. In addition, the inner circumference of the circle is displayed in green once the cutting sequence is complete. During the cutting sequence the force imparted on the third rotation transmitting assembly260is monitored by the strain gauge assembly320to ensure that maximum force limit is not exceeded. The process is deemed complete once the third rotation transmitting assembly260reaches a hard stop or a force threshold as detected by the strain gauge assembly320. This indicates that the knife has successfully dissected the tissue. Completion of the cutting sequence is indicated by another tone and the LED stops flashing and remains lit. With reference toFIG.82F, after the stapling and cutting sequences are complete, the user begins an unclamping sequence to release the anvil assembly510from the trocar member274by pressing on the top of the toggle control button30. As the toggle control button30is pressed up, the trocar member274is automatically extended distally, thereby moving the anvil assembly510away from circular reload400and unclamping the tissue to the preset anvil tilt distance. The unclamping sequence is illustrated on the display screen146. In particular, an unclamping animation shows the anvil assembly510moving distally and the head assembly512being tilted. In addition, the display screen146also shows a lock icon to show that the anvil assembly510is secured to the trocar member274. Once the anvil assembly510is moved away from circular reload400to its tilt distance, the display screen146shows the anvil assembly510in the extended state with the head assembly512in the tilted state. This indicates that the user may remove the circular adapter assembly200from the patient. The LED then turns off. Once circular adapter assembly200is removed, the user then may unlock the anvil assembly510from the trocar member274by pressing one of the left-side or right-side control buttons32a,32b,34a,34bof the of the power handle101for a predetermined period of time (e.g., 3 seconds or more). The display screen146shows which button needs to be pressed on the power handle101to unlock the anvil assembly510. As the user is pressing one of the control buttons32a,32b,34a,34b, the display screen146displays a countdown (e.g., 3, 2, 1) and the lock icon is shown to be in the unlocked state. At this point, the anvil assembly510is unlocked and may be removed. The user may then remove reload400as well as the severed tissue from the resection procedure. Circular adapter assembly200is also detached from handle assembly100and is cleaned and sterilized for later reuse. The shell housing10is opened and discarded, with the power handle101being removed therefrom for reuse. The powered stapler according to the present disclosure is also configured to enter recovery states during the clamping, stapling, and cutting sequences if any of the components, e.g., the power handle101, circular adapter assembly200, circular reload400, and/or the anvil assembly510, encounter errors. The recovery states are software states executed by main controller147that guide the user through correcting and/or troubleshooting the errors and allow the user to resume any of the clamping, stapling, and cutting sequences once the error is corrected. At the start of each operational sequence (e.g, clamping, stapling, firing, etc.), the main controller147writes to the storage device407of the circular adapter assembly200a recovery code associated with the operational sequence. Thus, at the start of the procedure the storage device407stores an initialization recovery code indicating that the circular adapter assembly200has not yet been used. However, as the circular adapter assembly200is used throughout the procedure, namely, progressing through the different sequences described above, corresponding recovery codes are written to the storage device407. In addition, the main controller147writes corresponding recovery states to the memory141. In either instance, this allows for replacement of either of the adapter assembly200and/or the power handle101depending on the error state as both of the components store the last recovery state locally, namely, in the storage device407or the memory141, respectively. With reference toFIG.87A, which shows a recovery procedure during the stapling sequence andFIG.88A, which shows a recovery procedure during the cutting sequence, during the procedure there may be instances that the power handle101identifies a flaw with one or more of the components of the power handle101, the circular adapter assembly200, and/or the reload400. These recovery procedures are illustrative and similar procedures are also envisioned to be implemented in other operational sequences of the power handle101, e.g., clamping sequence. The recovery procedures may include, but are not limited to, attaching a new power handle101to an adapter assembly200that is inserted into the patient, replacing the adapter assembly200and/or the reload400. When an adapter assembly200is attached to the power handle101, the power handle101reads the recovery code from the storage device407to determine the state of the adapter assembly200. The recovery code was written when the adapter assembly200was previously detached from the power handle101. As noted above, at the start of the procedure, the recovery code indicates the initial state, which directs the power handle101to transition into start-up sequence, e.g., calibration. If the adapter assembly200was detached in the middle of the procedure, e.g., clamping, stapling, cutting, etc., the corresponding recovery code provides the entry point back into the mainline flow after performing a recovery procedure. This allows the operator to continue the surgical procedure at the point where the adapter assembly200was originally detached. Similarly, in situations where the power handle101is being replaced, a new power handle101is configured to read the recovery state from the adapter assembly200. This allows the new power handle101to resume operation of the previous power handle101. Thus, during any of the operational sequences, e.g., clamping, stapling, and cutting, the adapter assembly200may be left in the corresponding configuration, e.g., clamped, stapled, etc., and after the new power handle101is attached, operation may be resumed. It will be understood that various modifications may be made to the embodiments of the presently disclosed adapter assemblies. Therefore, the above description should not be construed as limiting, but merely as exemplifications of embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the present disclosure.

11857195

Corresponding reference characters and labels indicate corresponding elements among the views of the drawings. The headings used in the figures should not be interpreted to limit the scope of the claims. DETAILED DESCRIPTION Provided herein are devices for controlling the flow rate and/or pressure within a vessel of a mammalian patient. In general, the devices in various aspects may occlude the vessel in a controlled manner to implement a treatment of an afflicted region. For example, in the case of vascular tissue injury associated with an ischemic stroke, the device in one aspect may be used to completely occlude the blood flow entering an area of clot-related vascular damage, also referred to herein as the penumbra. The device may also be used to gradually restore blood pressure and blood flow to the region as the injured vascular tissue is healed. In other aspects, the device may further deliver one or more substances to the vascular tissue occluded by the device to aid in the recovery of the vascular tissue during the treatment. In additional aspects, the devices may further include instrumentation to assess blood flow and/or blood pressure in the afflicted region of the patient to provide information regarding the health and/or functional status of the vascular tissue, the degree of occlusion imparted by the device to the vessel, and any other relevant information regarding the condition or flow environment of the afflicted region of the patient. Also provided herein are methods of using the devices for controlling the flow rate and/or pressure within a vessel of a mammalian patient. In one embodiment, the device may be operatively contacted with a vessel associated with an afflicted region such that the vessel is completely occluded initially. The configuration of the device may be gradually altered over time to reduce the device-related occlusion within the vessel. The configuration of the device may be altered according to a fixed and predetermined scheduled in one aspect, or the configuration may be altered based on assessments of the health and function of the vessel and/or afflicted tissue, either manually or by means of a feedback-based control system in other aspects. For example, the device may be operatively contacted with a blood vessel associated with an ischemic stroke such that the vessel is completely occluded. According to a predetermined or feedback-based schedule, the configuration of the device may be gradually altered to reduce the occlusion and thereby increase the flow rate and pressure within the vessel. Based on subsequent measurements of the health and function of the vessel and/or afflicted tissue, the configuration of the device may be adjusted to increase the occlusion if the measurements indicate degradation of the tissue or vessel and to decrease the occlusion if the measurements indicate the enhanced health and function of the afflicted tissues and associated vessel. In additional aspects, therapeutic compounds may be introduced into the afflicted area by the device to enhance the health and function of the afflicted tissues and associated vessel at any time during the treatment, including during full occlusion of the vessel by the device. The other additional aspects, the device may further include other means of treating the afflicted tissues. For example, in the case of treatment of an ischemic stroke using an aspect of the devices described herein, the device may further include additional features that allow the clot associated with the ischemic event to be removed from the afflicted vessel prior to subsequent treatment as described herein. In an aspect, the mammalian patient may be any mammalian organism. Non-limiting examples of mammalian organisms that are suitable patients in various aspects of the method include mammals from the Order Rodentia (mice); the Order Logomorpha (rabbits); the Order Carnivora, including Felines (cats) and Canines (dogs); the Order Artiodactyla, including Bovines (cows) and Suines (pigs); the Order Perissodactyla, including Equines (horses); and the Order Primates (monkeys, apes, and humans). In another aspect, the patient is a human. Any size, type, and/or location of vessel within the mammalian patient may be treated using the devices and methods described herein without limitation, so long as the device is capable of operatively contacting the vessel in order to control the flow rate and/or pressure as described herein. In various aspects, the vessel may include any biological structure, tissue, or organ capable of convectively transporting a fluid at a flow rate. Non-limiting examples of vessels include circulatory vessels, urinary tract vessels, digestive tract vessels, respiratory vessels, and ventricular system vessels. Non-limiting examples of circulatory vessels include capillaries, arterioles, venules, arteries, veins, hearts, lymph nodes, and lymphatic vessels. Non-limiting examples of urinary tract vessels include kidneys, ureters, bladders, and urethras. Non-limiting examples of respiratory vessels include oropharynxes, nasopharynxes, larynxes, tracheas, bronchi, bronchioles, and alveoli. The diameters of the circulatory vessels may range between about 10 μm and about 2 cm. In an aspect, if the device operatively contacts the vessel by implantation within the vessel, the vessels suitable for treatment by the device may be limited to those vessels large enough to accommodate the device and associated equipment including, but not limited to, a delivery device. The devices and methods of various aspects may be used as a treatment, or as part of a treatment, for a variety of afflictions. Non-limiting examples of afflictions amenable to treatment using aspects of the device and method include: ischemic strokes and other clot-related infarctions such as myocardial infarctions, pulmonary infarctions, splenic infarctions, limb infarctions, and avascular necrosis of bone tissue, various forms of cancers/tumors, aneurysms, stenosis dissolution, and diabetes-related circulatory afflictions. Various aspects of the vessel flow control devices and methods of using the devices to treat an affliction in a mammalian patient are present herein below. I. Vessel Flow Control Device In various aspects, the vessel flow control device may provide features to control the rate of flow and/or the pressure within a vessel in a selected region within a mammalian patient. Typically, this selected region may be an afflicted region associated with a vessel and/or an afflicted vessel. Non-limiting examples of vessels within selected regions include a vessel blocked by a clot or other structure within an infracted region; or a vessel providing blood to a region of tumor tissue. In an aspect, the vessel flow control device provides a number of useful functions when placed in operative connection with a vessel of a patient, including, but not limited to: complete obstruction of flow through the vessel; restoration of unobstructed flow through the vessel according to a predetermined schedule or in response to measurements related to the assessment of the health and/or function of the vessel; controlled release of one or more compounds to provide oxygen, nutrients, and or treatment to the vessel and/or associated region of the patient. a. External Vessel Flow Control Devices The vessel flow control device may be an external vessel flow control device operatively connected to the outside of the vessel of the patient in one aspect. In this aspect, the external vessel flow control device may include clamps and any other known suitable mechanical flow restriction element to releasably restrict flow through the vessel of the patient by a physical method. In another aspect, the vessel flow control device may include one or more electrodes applied externally to the vessel of the patient; activation of the electrodes may stimulate the contraction of smooth muscle tissue surrounding the vessel, resulting in the restriction of flow through the vessel. In yet another aspect, chemical vessel restrictors including, but not limited to dopamine and LEVOPHED, as well as chemical vessel dilators including, but not limited to, papaverine, may be administered in a sequence and amount sufficient to induce the constriction and dilation of the vessel according to a predetermined schedule. b. Implanted Vessel Flow Control Devices In another aspect, the vessel flow control device may be operatively connected by implanting the device within the lumen of the vessel upstream of the afflicted region. In this aspect, the device may be capable of reversibly or irreversibly changing shape, resulting in a change in cross-sectional area. At one extreme, the device may assume a shape having a cross-sectional area that completely blocks the lumen cross-sectional area, corresponding to an occlusion factor of 100%. The device may also assume a shape having a cross-sectional area that partially blocks the lumen cross-sectional area, corresponding to an occlusion factor of less than 100%. At another extreme, the device may assume a shape having a cross-sectional area that has essentially no blocking effect on the lumen cross-sectional area, corresponding to an occlusion factor of 0%. Occlusion factor, as used herein, describes the ratio of the cross-sectional area of vessel flow control device divided by the cross-sectional area of the vessel lumen expressed as a percentage. The implanted vessel flow control devices may be implanted within a vessel using a delivery device. Any known delivery device may be used to situate and secure the implanted vessel flow control devices in place including, but not limited to, catheters and guide wires. In aspect, the delivery device may be selected in order to fit within the vessel to be treated using the device. Non-limiting examples of catheters suitable for situating the implanted vessel flow control devices within the vessel include: neurovascular catheters; peripheral venous catheter (PVC); central venous catheters; arterial catheters; non-tunneled catheters including Quinton catheters; tunneled catheters including Hickman catheters, Broviac catheters, Groshong catheters, and peripherally inserted central catheters (PICC or PIC lines); balloon catheters; balloon-tipped catheters; coaxial Teflon catheters; irrigation catheters; intracardiac catheters; bronchospirometry catheters; and pulmonary artery catheters including Swan-Ganz catheters. The delivery device may be operatively attached to the implanted vessel flow control device. In addition, the delivery device may include elements to enhance the function of the implanted vessel flow control device including, but not limited to: tools for expanding or deploying a stent-type device; fluid supplies for inflating balloon-type devices; light sources and/or cameras for visualizing the implantation area; and conduits for the delivery of active compounds to treat the vessel. The conduits may also deliver other compounds including, but not limited to biodegrading agents to initiate the biodegrading of structural elements and/or coatings of the implanted vessel flow control devices. In an aspect, the implanted vessel flow control device may remain attached to the delivery device throughout a treatment of a vessel, and may further be used to remove at least part of the implanted vessel flow control device upon completion of the treatment. In another aspect, the delivery device may be detached from the implanted vessel flow control device before, during, or after the treatment. In this aspect, the implanted vessel flow control device may remain implanted within the patient after completion of the treatment, or at least a portion of the implanted vessel flow control device may be removed from the patient after the treatment using a recovery device. Any known recovery device known in the art may be used without limitation including, but not limited to, a recovery wire and/or a recovery catheter. If the implanted vessel flow control device remains implanted within the patient after the completion of the treatment, the implanted vessel flow control device may incorporate additional features to enhance the post-treatment function of the implanted vessel flow control device. For example, the implanted vessel flow control device may include an active compound such as a clot-inhibiting compound in any known time-released form including, but not limited to, a time-release coating that includes the active compound. In another example, at least a portion of the implanted vessel flow control device, up to and including the entire implanted vessel flow control device, may be constructed from a biodegradable material that is resorbed following the treatment. A biodegradable material, as used herein, refers to any material that biodegrades after exposure to the physical, biological, and/or chemical environment within the vessel. The biodegradable material may biodegrade spontaneously, or the biodegradable material may biodegrade after exposure to an extrinsic biodegrading agent introduced into the vessel. In an aspect, the biodegradation may occur by means of a mechanism that avoids releasing particles of biodegradable material into the vessel that may cause secondary blockages within the vessel. Non-limiting examples of suitable mechanisms by which the biodegradation may occur include: dissolving, leeching, resorption, and any combination thereof. The implanted vessel flow control devices may be provided in a variety of forms without limitation. Non-limiting examples of implanted vessel flow control devices include: balloon devices including at least one implanted inflatable/deflatable balloon, stent devices including a stent capable of expanding/contracting or biodegrading according to a predetermined schedule; and other biodegradable implants capable of biodegrading according to a predetermined schedule or in response to exposure to a dissolving agent. The implanted vessel flow control devices including balloon devices, stent devices, and other biodegradable implants are described herein below. i. Balloon Devices The implanted vessel flow control device may be a balloon device in one aspect.FIG.1is a longitudinal cross-sectional view of a balloon device100in one aspect. The balloon device100may include a balloon body102that has a roughly cylindrical shape when inflated. The balloon device100may further include a tapered proximal end104projecting in a proximal direction from the balloon body102; the proximal end104further contains a proximal opening106. The balloon device100may further include a tapered distal end108containing a distal opening110projecting in a distal direction from the balloon body102opposite to the proximal end104. The balloon100may be situated within a lumen112of a vessel114upstream relative to a clot116or other obstructive structure using a delivery device120. The term “upstream”, as used herein, may be defined by the direction of the flow118within the lumen112of the vessel. When fully inflated, the balloon body102may expand to a diameter essentially equal to the diameter of the vessel lumen when fully inflated, as illustrated inFIG.1. In this configuration, the balloon device100has an occlusion factor of 100%, and no flow may pass the balloon body102. When the balloon device has an occlusion factor of 100%, the region of the blood vessel114situated downstream of the balloon device100experiences essentially zero flow speed and relatively low pressure. Without being limited to any particular theory, the low pressure and zero flow speed in this downstream region may provide conditions well-suited for the recovery and healing of any vascular tissue within the downstream region that may be weakened by the formation and/or removal of the clot116. If the clot116is removed from the lumen112, the flow118through the vessel114may be reestablished up to physiological flow speeds and flow pressures. In an aspect, the balloon device100may be deflated as illustrated inFIG.2as a longitudinal cross-sectional view, causing a reduction in the diameter of the balloon body102such that the cross-sectional area of the balloon body102no longer fills the cross-sectional area of the lumen112, resulting in an occlusion factor of less than 100%. In this configuration, the flow118within the vessel114may pass the balloon body102in the annular space formed between the balloon body102and the lumen112; this reestablishment of flow in the vessel114results in a rise in the flow rate and pressure downstream of the balloon device100. In an aspect, the balloon may be deflated over a period of time sufficient to allow for the healing of the vascular tissues injured by the clot116. The rate at which the balloon device100may be deflated to reestablish flow within the vessel may be specified using a variety of methods discussed in detail herein below. In another aspect, the deflated balloon may be held in place using a delivery device120or other tethering device. a. Inflation/Deflation Features of Balloon Devices FIG.3illustrates a transverse cross-sectional view through the balloon body102of the balloon device100as taken along section line4-4inFIG.1. In this aspect, the balloon device100is formed from a thin flexible outer membrane202. The outer membrane202may be sealed to the inner cylinder204at the proximal end104and at the distal end108. Together, the outer membrane202and the inner cylinder204enclose a toroidal volume206that may enlarge and shrink as the balloon device100is inflated and deflated. The inner cylinder204further encloses a cylindrical internal volume208that opens to the proximal opening106and the distal opening110at opposed ends. In an aspect, a delivery device210may be situated within the internal volume208. In this aspect, the delivery device210may provide a means of situating the balloon device100upstream of the clot116as illustrated inFIG.1. The delivery device210may further provide pneumatic pressure to inflate and/or deflate the balloon device100. Other equipment may also be included or connected to the delivery device210including, but not limited to flow measurement devices, pressure sensors, temperature sensors, clot ablation or dissolving devices, and additional conduits through which additional substances may be introduced into the region of the lumen112situated downstream of the balloon device100. Non-limiting examples of additional substances include: oxygenating compounds, nutrients, compositions for the treatment of the afflicted region downstream of the balloon device100, clot-dissolving compounds, vascular dilation compounds, vascular constriction compounds, and any other suitable substance. A more detailed description of the delivery device210, its associated equipment, and uses are described in detail herein below. The balloon device100may be constructed from any suitable semi-compliant material known in the art. Non-limiting examples of suitable semi-compliant material include ethylene-vinyl acetate, polyvinyl chloride (PVC), olefin copolymers or homopolymers, polyethylenes, polyurethanes, crosslinked low density polyethylenes (PETs), highly irradiated linear low density polyethylene (LDPE), acrylonitrile polymers and copolymers, acrylonitrile blends and ionomer resins. In another aspect, if the osmotic movement of fluid in or out of the balloon device100is desired, at least a portion of the balloon device100may be incorporated from a semi-permeable material including, but not limited to urethane. In various aspects, as described in detail herein below, a particular portion of the balloon device100incorporates a semi-permeable material in order to achieve any one of a variety of advantageous properties in use. In other aspects, the balloon device100may comprise alternative designs, resulting in different properties, in particular as related to the changes in cross-sectional area to reduce the occlusion factor. In the balloon device100illustrated inFIG.1andFIG.2, the vessel flow118moves through a space formed between the vessel wall114and the balloon body102when the balloon device100is deflated. In another embodiment, illustrated inFIGS.4A and4B, which are transverse cross-sections of the toroidal volume of the balloon device100A, the toroidal volume may be subdivided into two or more lobes; four lobes502A-502D are illustrated inFIGS.4A and4B. When the balloon device100A is inflated, as illustrated inFIG.4A, the lobes502A-502D are pressed tightly against each other, filling the entire cross-sectional area of the lumen of the vessel (not shown) and resulting in an occlusion factor of about 100%. When the balloon device100A is deflated, as illustrated inFIG.4B, the lobes502A-502D may be designed to separate at their respective contact surfaces, forming channels504A-5040through which the vessel flow (not shown) may pass. In an additional aspect, as illustrated inFIGS.5A and5Bwhich are transverse cross-sections of the balloon device100B, the balloon device100B may be designed such that a central passage is formed by the deflation of the balloon device100B. As illustrated inFIG.5A, the inflated balloon device100B includes a toroidal volume606bounded by an outer membrane602and an inner membrane604. The inner membrane604encloses in inner lumen608which is essentially closed when the balloon device100B is fully inflated, resulting in an occlusion factor of essentially 100%. When the balloon device100B is deflated, as illustrated inFIG.5B, the inner membrane604expands toward the outer membrane602, thereby dilating the inner lumen608. This inner lumen608may function as a conduit to carry vessel flow (not shown) into the region of the vessel downstream of the balloon device1008, resulting in an occlusion factor of less than 100%. b. Balloon Devices with Biodegradable Coatings In yet another aspect, the balloon device100C, illustrated inFIGS.6A and6Bas transverse cross-sections, may include an outer coating708attached to the outer membrane702of the device100C. In this aspect, the central volume706enclosed by the outer membrane702and the inner membrane704may remain relatively unchanged during the treatment using the balloon device100C. However, the outer coating708may be constructed of a material that may spontaneously biodegrade under the physical and chemical conditions characteristic of the vessel114in which the balloon device is situated in one aspect. In another aspect, the outer coating708may incorporate a material that biodegrades upon exposure to a separate biodegrading agent introduced into the vessel114. Regardless of the proximate cause of the biodegrading of the outer coating708, the reduced cross-sectional area occupied by the balloon device100C forms a toroidal space710between the outer layer708and the vessel114that allows for vessel flow into the lumen volume of the vessel situated downstream from the balloon device100C. FIGS.6C and6Dare transverse cross-sections of a balloon device100D in another aspect. In this aspect, the balloon device100G may be a cylindrical shell that maintains contact between the vessel114and the outer membrane702of the device100G. An inner coating712may be attached to the inner membrane704of the device100G. The inner coating712may reduce the extent of the volume706enclosed by the inner membrane704. In a manner similar to the outer coating708described herein previously, the inner coating712may be constructed of a material that may spontaneously biodegrade under the physical and chemical conditions characteristic of the vessel114or upon exposure to a separate biodegrading agent introduced into the vessel114. The biodegradation of the inner coating712results in an increase of the extent of the volume706enclosed by the inner layer704, thereby allowing for vessel flow through the volume706. c. Osmotically Active Liquids of Balloon Devices In one aspect, the balloon device100may be introduced by delivery device that includes a guide wire situated within an inner lumen of a multi-lumen catheter. The enclosed volumes of the balloon device100may be filled with a liquid introduced by an outer lumen of catheter to inflate the device100. Any suitable incompressible liquid may be used to inflate the devices. Non-limiting examples of liquids suitable for inflating the balloon devices include: saline solution, plasma, whole blood, hydrophilic compounds, dopamine, papaverine, oxygenated fluids, TPA (Tissue Plasminogen Activator) and any other suitable incompressible fluid. In an aspect, the concentration of the liquid introduced into the device100may be selected to be hyperosmotic, isoosmotic, or hypoosmotic relative to the surrounding blood within the vessel in which the device100is situated. In this aspect, if the outer membrane of the balloon device is constructed of a semipermeable material including, but not limited to, a urethane material, the introduction of the liquid into the device100may result in the passive movement of fluid into or out of the balloon device100, depending on the tonicity of the liquid inside the device100. In an aspect, the tonicity of the liquid inside the device100may be selected to result in a net movement of fluid into the balloon device, thereby passively maintaining the device100in an inflated configuration. In another aspect, the tonicity of the liquid inside the device100may be selected to result in a net movement of fluid out of the balloon device100. In this aspect, the net movement of fluid out of the device100may be used as a passive mechanism by which vessel flow is reestablished in the vessel. As the fluid is driven from the device100by the osmotic gradient, the volume of the device100may subsequently shrink gradually over time, resulting in a slowly decreasing occlusion factor and the gradual reestablishment of vessel flow. The rate of transition to full physiological flow conditions in the vessel may be specified in part by the degree of tonicity of the liquid introduced into the balloon device100. In addition to passively reintroducing vessel flow, the passive movement of fluid out of the balloon device in this aspect may be further exploited to deliver compounds to the region in which the device is situated. In another aspect, the liquid introduced into the device100may further include one or more additional dissolved compounds including, but not limited to, active pharmaceutical compounds, oxygen-bearing compounds, nutrients, clot-dissolving compounds, and other suitable additional compounds. In order to deliver the one or more dissolved compounds to the desired region within the vessel, the balloon device may incorporate additional design features to implement the movement of fluid out of the device within specified regions of the device100. For example, as illustrated in the longitudinal cross-sectional view ofFIG.7, the balloon device100D may be constructed using a semi-permeable material such as urethane on the distal end108, and using a non-permeable material on the remaining balloon body102and proximal end104portions of the device100D. If the device100D is filled with a liquid802having a tonicity that results in the net movement of fluid out of the device100D, the construction of the device100D limits the outward movement of fluid802to the distal end108. If a dissolved compound804is included in the liquid802, this dissolved compound804may be carried by the moving fluid802preferentially to the region of the lumen112situated downstream of the device100D. For example, if the dissolved compound was a clot-dissolving compound, the device100may function to dissolve the clot116as well as to protect the lumen112and vessel wall114from potentially harmful elevated pressures and flow speeds. In another embodiment, the net movement out of the device100D may be driven by increased hydrostatic pressure within the device100D in addition to or instead of by osmotic pressure. In another aspect, the balloon device100may be constructed using a semi-permeable material including, but not limited to, urethane situated around the perimeter1302of the balloon body102as illustrated inFIG.12. In this aspect, if the tonicity of the fluid introduced into the balloon device100G results in a net outward movement of fluid from the device100G, the expelled fluid1304may be situated in the gap between the perimeter1302of the balloon body and the vessel wall114. Without being limited to any particular theory, this fluid movement may inhibit the adhesion of the balloon body102to the vessel wall114and/or inhibit the formation of thrombi within this area of contact. If the liquid802introduced into the balloon device100G further includes a dissolved anti-adhesion compound in an aspect, the fluid movement may deliver the anti-adhesion compound between the perimeter1302and vessel wall114, further inhibiting adhesion and/or clot formation. In another embodiment, the fluid movement out of the device100G may result from elevated hydrostatic pressure within the device100G, in addition to or instead of from osmotic pressure. d. Multi-Balloon Devices In an aspect, the implanted vessel flow control device may be a multi-balloon device. In one aspect, the multi-balloon device may include an upstream balloon and at least one downstream balloons situated in the vessel downstream of the afflicted area. For example, within a vessel that bifurcates into two downstream branches, the upstream balloon may be situated upstream of the bifurcation, and each of downstream balloons may be situated within a branch of the vessel downstream of the bifurcation point. As illustrated inFIG.8, a two-balloon device900may include two balloons100E and100F similar in design to the single balloon devices100described herein previously. In this aspect, the two balloons are arranged sequentially along the length of a multi-segmented catheter902that includes three segments: a large-diameter segment904, an intermediate diameter segment906, and a small diameter segment908. The small diameter segment908nests within the intermediate diameter segment906and the intermediate diameter segment906nests within the large-diameter segment904. Thus, the segments904,906, and908may be coaxially arranged with each other such that the small diameter segment908is coaxially located within the intermediate diameter segment906, which is coaxially located within the large diameter segment904. The proximal end910of the multi-segment catheter902, which includes all three segments904,906, and908, extends out past the region at which the catheter902was introduced into the vessel lumen112of the patient. The proximal balloon100F is sealed to the large-diameter segment904at location906and is further sealed to the intermediate diameter segment906at location912. The distal balloon100E is sealed to the intermediate diameter segment906at location914and is further sealed to the small diameter segment908at location916. In this aspect, the two balloons100E and100F may be separated by a distance ranging from about 1 inch to about 3 inches. With this arrangement, the proximal balloon100F may be inflated or deflated by introducing or removing a fill liquid as described herein above via a fluid pathway defined between an outer circumferential surface of the intermediate-diameter segment906and an inner circumferential surface of the large-diameter segment904. Similarly, the distal balloon100E may be inflated or deflated by introducing or removing a fill liquid via a fluid pathway defined between an outer circumferential surface of the small-diameter segment908and an inner circumferential surface of the intermediate diameter segment906. In this aspect, each balloon100E or100F is hydraulically independent of the other balloon, providing the ability to inflate or deflate one balloon device independently of the other device. In use, this hydraulically independent design may result in at least several useful features for the device900. In one aspect, illustrated in the longitudinal cross-sectional view ofFIG.10, the proximal balloon100F may be deflated while the distal balloon100E is maintained in an inflated configuration. This configuration of the device900may provide access to the region112downstream of the proximal balloon100F, which may include the afflicted region of the patient containing a clot or other abnormality. In this configuration, the afflicted region of the lumen112may be rendered accessible to additional instruments such as delivery devices, or accessible to contact by treatment compounds such as clot-dissolving substances, by oxygenated blood and/or nutrients, and/or any other suitable instrument or compound. By maintaining the distal balloon100E in an inflated configuration, the upstream flow918may contact the afflicted region112without exposing the afflicted region112to high flow rates. In another aspect, the configuration illustrated inFIG.10may be used to prevent the formation of thrombi within the contact area between the proximal balloon100F and the vessel wall114. In another aspect, illustrated in the longitudinal cross-sectional view ofFIG.11, the distal balloon100E may be deflated while the proximal balloon100F is maintained in an inflated configuration. This configuration of the device900may provide fluidic contact between the afflicted region112and the vessel region downstream of the distal balloon100E. In this configuration, the afflicted region112and surrounding tissues may be rendered accessible to additional instruments such as additional delivery devices introduced into the vessel lumen downstream of the device900, or accessible to contact by treatment compounds such as clot-dissolving substances, by oxygenated blood and/or nutrients, and/or any other suitable instrument or compound. By maintaining the proximal balloon100F in an inflated configuration, the upstream flow918remains sheltered from the physiological blood flow, thereby preventing the exposure of the afflicted region of the lumen112to the elevated physiological pressures and flow rates. In another aspect, the configuration illustrated inFIG.11may be used to prevent the formation of thrombi within the contact area between the distal balloon100E and the vessel wall114. In addition to the advantages of the dual-balloon device900described herein above, this arrangement may further enhance the degree of control over the flow rate and pressure experienced within the afflicted region112of the vessel. For example, the distal balloon100E may be differentially inflated or deflated relative to the proximal balloon100F in order to increase or decrease the pressure experienced with the afflicted region112. Other combinations of differential inflation or deflation of the balloons100E and100F are possible and may result in additional degrees of enhanced control over the flow conditions experienced by the afflicted region112of the vessel. In another aspect, the small diameter segment908extends uninterrupted from the upstream side to the downstream side of the device900, as illustrated inFIG.8. As a result, the small diameter segment908provides a bypass of the device900from the proximal side to the distal side through which a variety of substances may be provided to the vessel downstream of the device900. For example, the small diameter segment908may be used to deliver one or more additional substances including, but not limited to, oxygenated blood, nutrients, artificial blood, therapeutic compounds, and any other suitable compound to the region of the vessel downstream from the device. Because the device900typically completely blocks vessel flow for at least a portion of its working lifetime, the vessel and tissues downstream of the device900may suffer oxidative, nutritive, and other physiological stresses due to the treatment of the patient using the device900. By introducing the one or more additional substances to the region of the vessel situated downstream of the device900, the vessel in this region and its associated tissues may be maintained in a physiologically viable state during the course of treatment using the device900. e. Balloon Instrumentation In another aspect, the balloon devices100and/or900described herein above may additionally include instrumentation to measure relevant physical and chemical conditions in the vessel regions upstream, immediately adjacent, and/or downstream of the device100or900. Non-limiting examples of suitable physical and chemical conditions include: flow rate, pressure, temperature, pH, hematocrit, platelet count, electrical activity, cytokine, glucose, oxygen, carbon dioxide, and other relevant compound concentrations. Any known instrumentation may be incorporated into the balloon devices100and/or900, as long as the selected instrumentation is biocompatible and of suitable size for introduction into the vessel of the patient. Non-limiting examples of suitable instrumentation for incorporation into the devices100and/or900in various aspects include thermocouples for measuring temperature, piezoelectric pressure sensors, heated velocity sensors, and any other known suitable miniature sensor. For example, a heated velocity sensor may include a heated or cooled strip of material upon which one or more strain gages are mounted. The flow rate may be determined by assessing the effect of conductive heating or cooling induced by the vessel flow on the strain gage resistance. In various aspects, the instrumentation may be mounted at any location relative to the balloon device without limitation. In one aspect, two pressure sensors may be situated such that one pressure sensor measures the pressure upstream of the balloon device100or900, and the second pressure sensor measures the pressure downstream of the balloon device. A comparison of the upstream and downstream pressures may provide an indication of the flow vessel flow conditions. For example, if the upstream pressure sensor indicates a higher pressure than the downstream pressure sensor, this differential may be interpreted as confirmation that the vessel flow is significantly occluded by the device100or900. In this example, an equalization of the upstream and downstream pressures may be expected as the occlusion diminishes. ii. Stent Devices In another aspect, the vessel flow control device may be a stent device.FIG.13is a longitudinal cross-section of a stent device1400in an aspect. The stent device1400may include a stent body1402that has a roughly hollow cylindrical shape when deployed. The stent body1402may include a proximal end1404containing a proximal opening1406, and a distal end1408containing a distal opening1410. In an aspect, the stent1400may be constructed using any material known to be suitable for stent construction including, but not limited to stainless steel; NITINOL; bio-resorbable materials including PGA, PDS, PGA-PCL, and PLLA; biodegradable materials including enteric coating materials and hydrogel materials; PEEK; any other known stent materials, and any combination thereof. The stent1400may be situated within a lumen112of a vessel114upstream relative to a clot116or other obstructive structure; upstream may be defined by the direction of the flow118in the lumen112. In another aspect the stent1400may be situated over the clot116or other obstructive structure; in this aspect, the stent1400may compress the clot116against the wall of the vessel114. When fully deployed, the stent body1402may expand to a diameter essentially equal to the diameter of the vessel lumen as illustrated inFIG.13. In addition, the stent1400may include an occlusive element1412to impede the vessel flow118to a predetermined degree, resulting in a predetermined occlusion factor. The occlusive element1412may be any structural feature within the stent1400capable of occluding the vessel flow118. As illustrated inFIG.13, the occlusive element1412may be an approximately hourglass-shaped solid structure that narrows to a channel1414through which the vessel flow may pass. In an aspect, the occlusive element1412may be fabricated from a biodegradable material capable of biodegrading and/or resorbing over a predetermined period, resulting in a gradual decrease of the occlusion factor, and a commensurate increase in vessel flow, in accordance with a predetermined schedule. In another aspect, the occlusive element1412may be fabricated from a semipermeable membrane filled with an osmotically active fluid that gradually releases fluid into the vessel, resulting in the gradual widening of the channel1414, thereby decreasing the occlusion factor of the stent1400. In another aspect, the entire stent1400may be constructed from at least one biodegradable material. In this aspect, the entire stent1400may partially or completely biodegrade and/or resorb over time. FIG.14is a transverse cross-sectional view of the stent1400taken at section A-A as denoted inFIG.13.FIG.14illustrates the occlusive element1412situated within the stent1402as well as the channel1414formed within the center of the occlusive element1412. In this configuration, the stent device1400has an occlusion factor of about 100% or substantially 100%, and no flow or substantially no flow may pass the stent body1402.FIG.15is a longitudinal cross-section of the stent1400illustrated inFIG.13with reduced occlusive element1412and widened channel1414. In this configuration, the occlusion factor of the stent device1400may be significantly reduced to a level as low as about 5%, thereby allowing a significantly higher vessel flow118through the vessel lumen112. Detailed descriptions of various aspects of the design and characteristics of the occlusive element1412are provided herein below. Referring back toFIG.13, if the clot116is removed from the lumen112, the flow118through the vessel114may be reestablished up to physiological flow speeds and flow pressures. In an aspect, the stent1400may be gradually collapsed as illustrated in the longitudinal cross-sectional view ofFIG.15, causing a reduction in the diameter of the stent body1402such that the cross-sectional area of the stent body1402no longer fills the cross-sectional area of the lumen112, resulting in an occlusion factor of less than 100%. In this configuration, the flow118within the vessel may pass the stent body1402in the annular space formed between the stent body1402and the lumen112; this establishment of flow in the vessel114results in a rise in the flow rate and pressure downstream of the stent device1400. The gradual collapse of the stent1400may be implemented in a passive structure that spontaneously collapses over time, or the gradual collapse of the stent may be actively controlled by a practitioner in various aspects. For example, the stent1400may be constructed from NITINOL memory wire in a configuration capable of collapsing a predetermined amount in response to a physical factor such as an electrical current or transfer of thermal energy or a mechanical input. In another embodiment as shown inFIG.16, which is a longitudinal cross-sectional view of the stent1400illustrated inFIG.14in a biodegraded condition, the occlusive element1412may biodegrade to produce an enlarged channel1414within the occlusive element1412through which vessel flow may travel. As the channel1414gradually widens, the occlusion factor decreases proportionally. In an aspect, the occlusive element1412may be designed to biodegrade at a steady and predetermined rate, resulting in a gradual increase in vessel flow velocity according to a predetermined schedule. In another aspect, the occlusive element1412may be formed into an expandable structure such as an iris-type structure, wherein the expandable structure is designed to slowly expand according to a predetermined schedule, resulting in the gradual increase of vessel flow through the stent1400. The dissolution and/or expansion of the occlusive element may occur spontaneously, or in response to exposure to a physical and/or chemical agent that triggers the dissolution or expansion. In an aspect, the dissolution and/or expansion of the occlusive element1412may occur in response to exposure to an injected medium introduced into the vessel114upstream of the stent1400. In an aspect, the occlusive element1412may biodegrade over a period of time sufficient to allow for the healing of the vascular tissues injured by the clot116. The rate at which the occlusive element1412biodegrades to reestablish flow within the vessel114may be specified using a variety of methods discussed in detail herein below. In an aspect, the interior and exterior surfaces of the stent1400may be coated up to the full extent of the stent1400with a variety of coating materials including, but not limited to, biodegradable materials, resorbable materials, clot-dissolving materials, and any other known coating material suitable for use in an implantable stent design. In one aspect, the stent1400may be partially or fully coated to facilitate in the compression of a clot or other structure, resulting in the reestablishment of physiological vessel flow. In another aspect, the occlusive element1412may incorporate biodegradable and/or bioresorbable materials in a configuration designed to biodegrade at a predetermined rate. In an aspect, the occlusive element1412may be constructed partially of biodegradable and/or bioresorbable materials with additional non-biodegradable structural elements such as cross members, a mesh, and/or a screen. In other aspects, the occlusive element1412may be constructed entirely of biodegradable and/or bioresorbable materials. The dimensions and design of the occlusive element1412may be selected based on one or more of at least several factors including, but not limited to the desired dissolution rate, the desired structural integrity of the stent1400, the ease of deployment and collapse of the stent1400in use, and any other relevant factor. iii. Hybrid Devices In other additional aspects, the vessel flow control device may include any combination of any number of external flow control devices and implantable flow control devices without limitation. For example, the vessel flow control device may include an external flow control device such as an external clamp and an implantable flow control device such as a stent device. In another example, the vessel flow control device may include a stent device as well as a balloon device in combination. II. Methods of Using Vessel Flow Control Device The vessel flow control device may be used to treat an afflicted region of a patient using methods described herein below in various aspects. In one aspect, a vessel flow control device is situated in a vessel of a patient upstream of the afflicted region and configured to an occlusion factor of essentially 100%, resulting in the essentially complete obstruction of the vessel flow to the afflicted region. As the afflicted region recovers, the occlusion factor of the vessel flow control device may be gradually decreased, resulting in a gradual increase in vessel flow and/or vessel pressure in the afflicted region. This gradual decrease of the occlusion factor may be specified using any one of at least several control methods. Non-limiting examples of suitable control methods include: autonomous device-based adjustments such as the dissolution of obstructive materials in the device as described herein above; manual adjustment by a medical practitioner; automated adjustment of the vessel flow according to a predetermined schedule; and/or automated adjustment of the vessel flow based on commands from a feedback control system. a. Treatment Algorithm A procedure for treating an afflicted region of a patient using a vessel flow control device is provided in one aspect. A flowchart1000illustrating the steps of the procedure is provided inFIG.9. In this aspect, a delivery device with the attached vessel flow control device may be inserted into the vessel of the patient at step1002. After the delivery device has been inserted, the flow control device may be situated upstream of the afflicted region of the patient at step1004. The flow control device may then be deployed to occlude the vessel and stop blood flow to the afflicted region. In this aspect, the flow control device may be deployed to an occlusion factor of about 100% for a predetermined time at step1006. Once the flow control device has been completely deployed, the occlusion factor of the flow control device may be reduced by about 1% to restore some blood flow past the flow control device to the afflicted area at step1008. The afflicted region may then be monitored for vascular leakage for a predetermined period, as shown in step1010. In this aspect, the occlusion factor and vascular leakage may be assessed and this information may be used to determine any adjustments to be made to the occlusion factor of the device to increase or decrease the flow to the vessel. If the occlusion factor is determined to be not equal to 100% or 0% at step1012and if there is no vascular leakage at step1014, then the occlusion factor of the flow control device may be reduced by another 1% at step1016to increase the blood flow in the vessel. After the reduction in the occlusion factor, the afflicted region may again be monitored for vascular leakage at step1010. If the occlusion factor is not equal to 100% or 0% at step1012and if there is vascular leakage indicated at step1014, then the occlusion factor of the flow control device may be increased by about 1% at step1018to decrease the flow through the vessel in order to stabilize the patient or treatment. Steps1010,1014,1016and1018are repeated until the occlusion factor reaches either 100% indicating irreparable vessel damage or 0%, indicating reestablishment of physiological flow in the vessel. In this aspect, after step1010, if the occlusion factor reaches 100% at step1012, and the duration of treatment indicated at step1020is greater than a treatment window representing a maximum treatment time within which a favorable response is expected, then a permanent flow blocking device may be installed and the delivery device may be removed at step1022. If the occlusion factor reaches 100% at step1012, and the duration is not greater than the treatment window at step1020, then the afflicted region may be monitored for vascular leakage for a predetermined period of time at step1010to assess whether the condition of the vessel is improved. If the occlusion factor reaches 0% at step1012, then the vessel is indicated as healed, and the delivery device and the flow control device may be removed at step1024. c. Methods of Monitoring Blood Flow In various aspects, the adjustments to the vessel flow rate during the treatment of an afflicted region of a patient may be influenced by measurements obtained to monitor the blood flow within the afflicted region. For example, measurements that detect vascular leakage within the afflicted region may indicate the need to decrease the vessel flow by increasing the occlusion factor of the device. Blood flow in the vicinity of the vessel flow control device and vascular leakage may be monitored during treatment using any known method. Non-limiting examples of suitable methods for monitoring blood flow and vascular leakage include: angiogram, ultrasound, Doppler ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), heat transfer, patient neurological tests, and/or any other method of monitoring blood flow known in the art. In an aspect, an angiogram may be used to monitor blood flow by injecting a contrast medium from a delivery device such as a catheter and measure the rate of movement of the contrast medium down the vessel. Ultrasound may be used in an aspect to directly image blood flow or may be used as an ultrasonic flow meter by measuring the transit time between pulses from ultrasound transducers in opposite direction. In another aspect, Doppler ultrasound may utilize the change in pitch of reflected sound waves off of moving blood cells to measure blood flow. CT or computerized axial tomography (CAT) may be used with or without a contrast agent to measure blood flow by comparing sequential scans. In some aspects, CT and/or CAT may be used with xenon or positron emission tomography (PET) for enhanced imaging. In yet another aspect, MR may be used to track blood flow including, but not limited to, instant MRI, functional MRI, or MR angiography. The measurement of heat loss of a device in the blood stream may measure the flow of blood past the device in one aspect. d. Control Methods The occlusion factor of the vessel flow control device may be increased or decreased to control flow in vessels using any of the methods and structures described herein previously. Non-limiting examples of methods of controlling blood flow and the occlusion factor of the device include autonomous device-based adjustments, manual adjustments, programmable adjustments, and feedback control adjustments. In an aspect, the vessel flow control device may incorporate features and materials that result in the gradual decrease in occlusion factor due to the intrinsic properties of the device100. In an aspect, the flow control device100may be constructed of a material that may lose pressure or biodegrade at a constant rate, including, but not limited to, a biodegradable material, a porous material, urethane, or any other material known in the art. In another aspect, the flow control device100may be made of a material that may have an adjustable osmosis rate. In this aspect, various materials may be flushed over or inside the flow control device100to change the deflation rate and alter the occlusion factor. In an aspect, the pressure losses within the device may be used to alter the occlusion factor of the device as described herein previously. In another aspect, the occlusion factor of the device may be manually controlled.FIG.17is a schematic diagram illustrating the manual control of the occlusion factor of the vessel flow device100by a medical practitioner1704. After the vessel flow control device100is situated within a vessel114upstream of an afflicted region112of a patient1702, a medical practitioner1704may manually adjust the occlusion factor of the device100using a manual adjustment apparatus1706such as an adjustment syringe as illustrated inFIG.17. The medical practitioner1704may monitor the vessel flow in the afflicted region112using one or more measurements1708described herein previously, such as ultrasound or MRI imaging. For example, the medical practitioner1704may manually decrease the occlusion factor of the device110after observing measurements1708that indicate normal vessel flow in the afflicted area112. This manual adjustment results in increased vessel flow through the afflicted region112. The medical practitioner1704may continue to monitor the measurements1708and make additional manual adjustments to the occlusion factor of the device100using the manual adjustment apparatus1706as needed. In this aspect, manual adjustment methods may include, but are not limited to, manipulating fine adjustment syringes and/or stop-cocks to control the decrease or increase of the occlusion factor of the flow control device100. In another aspect, manual adjustment may use fixed rate/flow items to control the decrease or increase of the occlusion factor of the flow control device. The blood flow may change in this aspect by manually adjusting the constant leak rate of the flow control device, resulting in a constant increase or decrease in the occlusion factor of the flow control device. In another aspect, the blood flow may be controlled by the use of a manual flow, osmosis, or a leak rate device that may be attached to the flow control device to control removal of fluid from the flow control device to increase or decrease the occlusion factor. A programmable device may be used to control blood flow and the increase or decrease of the occlusion factor of the flow control device in another aspect.FIG.18is a schematic diagram illustrating a method of controlling the occlusion factor of the vessel flow control device100using a programmable device1802in an aspect. In this aspect, the programmable device1802may send a series of control signals to an automated adjustment device1804. In response to the series of control signals received from the programmable device1802, the automated adjustment device may implement the adjustment of the occlusion factor of the device100. In another aspect, the series of control signals generated by the programmable device1802may be specified, adjusted, and/or manually input into the programmable device1802by the medical practitioner1402. For example, the medical practitioner1402may select a more gradual rate of adjustment implemented by the programmable device1802. The programmable device1802may include CPU, processors, and computer readable media that execute stored commands and/or algorithms to implement a series of adjustments to the occlusion factor of the vessel flow control device100according to a predetermined schedule. The programmable device1802may use a predefined adjustment rate that may follow a pre-stored rate of blood flow or pressure increase or decrease. In an aspect, the programmable device1802may follow a programmable but defined rate of change. A motorized syringe or other adjustment device1804may be used to increase or decrease the occlusion factor at a constant fixed rate in one aspect. An electronic syringe or adjustment device1804in an aspect may allow multiple pre-stored changes to stop and start a constant or fixed rate flow control device100to increase or decrease the occlusion factor. In another embodiment, a feedback control system may be used to control the blood flow or pressure using feedback from measured signs and symptoms from the patient. In an aspect, external patient metrics may be used to automatically change the rate of increase or decrease of the occlusion factor of the flow control device and change the corresponding blood flow/pressure. In another aspect, internal vascular patient metrics and/or patient signs and symptoms may automatically change the rate of increase or decrease of the occlusion factor of the flow control device and change the corresponding blood flow/pressure. FIG.19is a schematic diagram illustrating the control of the occlusion factor of the vessel flow control device100using a feedback control device1902. The feedback control device1902may include CPU, processors, and computer readable media that execute stored commands and/or algorithms to implement a series of adjustments to the occlusion factor of the vessel flow control device100based on measured quantities related to blood flow within the afflicted area112as described herein above. For example, the feedback control device1902may execute stored instructions to implement a control algorithm similar to the algorithm described herein above and illustrated inFIG.9. Referring back toFIG.19, the measured quantities received by the feedback control device1902may be obtained by external measurement devices1708such as ultrasound and/or MRI imaging, and optionally by measurements obtained by internal instrumentation1904such as heated flow rate sensors or piezoelectric pressure sensors as described previously herein. The feedback control device1902processes the measured quantities received from the external measurement devices1708and/or internal instrumentation1904, and transmits a control signal to the adjustment device1804, which implements the adjustment of the occlusion factor of the vessel flow control device100. In another aspect, the medical practitioner1704may manually input, override, and/or modify the control commands transmitted by the feedback control device1902. a. Treatment of Ischemic Stroke In an aspect, the method described herein above may be used to treat an ischemic stroke in a mammalian patient. In this aspect, the vessel flow control device may be situated within a brain circulatory vessel upstream of an ischemic region. The vessel flow control device may completely occlude the vessel flow while a clot situated downstream of the vessel flow control device is removed. In one aspect, the vessel flow control device may be a dual balloon device implanted such that the clot is situated between the distal balloon and the proximal balloon of the dual balloon device. The dual balloon device may further administer clot-dissolving compounds and/or other treatments to reduce or eliminate the clot from the brain blood vessel. The method described herein above may then be used to gradually restore blood flow, while preventing hemorrhaging of the brain circulatory vessel during the recovery of the patient. b. Treatment of Tumors In an aspect, the method described herein above may be used to enhance the effects of chemotherapeutic compounds against tumor cells and/or tissues. In an aspect, the vessel flow control device may be situated within a circulatory vessel responsible for supplying blood to the tumor cells and/or tissue. The vessel flow control device may be configured to reduce the blood flow to the tumor cells and/or tissue, resulting in the shrinkage of the tumor. Upon removal of the tumor, the vessel flow control device may be configured to enhance the blood flow to the tissues surrounding the excised tumor, thereby enhancing the recovery of this surrounding tissue. c. Treatment of Other Disorders In an aspect, the method described herein above may be used to enhance the treatment of other disorders including, but not limited to diabetes, aneurisms, stenosis dissolutions, arterial repairs, and any other disorder that may benefit from controlled vessel flow and/or drug release. In an aspect, the occlusion of vessel flow may be coupled with the release of a therapeutic compound in order to lengthen the dwell time of the compound in the vicinity of the target cells and/or tissues. In addition, the vessel flow may be increased after a predetermined treatment time to enhance the removal of the compound from the vessel of the patient. The foregoing merely illustrates the principles of the invention. Various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein. It will thus be appreciated that those skilled in the art will be able to devise numerous systems, arrangements and methods which, although not explicitly shown or described herein, embody the principles of the invention and are thus within the spirit and scope of the present invention. From the above description and drawings, it will be understood by those of ordinary skill in the art that the particular embodiments shown and described are for purposes of illustrations only and are not intended to limit the scope of the present invention. References to details of particular embodiments are not intended to limit the scope of the invention.

11857196

DETAILED DESCRIPTION OF THE INVENTION Turning toFIG.1, a detachment system100of the present invention, and specifically the distal portion of the detachment system100, is illustrated. The detachment system100includes a pusher102that is preferably flexible. The pusher102is configured for use in advancing an implant device112into and within the body of a patient and, specifically, into a target cavity site for implantation and delivery of the implant device112. Potential target cavity sites include but are not limited to blood vessels and vascular sites (e.g., aneurysms and fistula), heart openings and defects (e.g., the left atrial appendage), and other luminal organs (e.g., fallopian tubes). A stretch-resistant tether104detachably couples the implant112to the pusher102. In this example, the tether104is a plastic tube that is bonded to the pusher102. A substantially solid cylinder could also be a design choice for the tether104. The stretch resistant tether104extends at least partially through the interior lumen of an implant device112. Near the distal end of the pusher102, a heater106is disposed in proximity to the stretch resistant tether104. The heater106may be wrapped around the stretch resistant tether104such that the heater106is exposed to or otherwise in direct contact with the blood or the environment, or alternatively may be insulated by a sleeve, jacket, epoxy, adhesive, or the like. The pusher102comprises a pair of electrical wires, positive electrical wire108and negative electrical wire110. The wires108and110are coupled to the heater106by any suitable means, such as, e.g., by welding or soldering. The electrical wires108,110are capable of being coupled to a source of electrical power (not shown). As illustrated the negative electrical wire110is coupled to the distal end of the heater106and the positive electrical wire108is coupled to the proximal end of the heater106. In another embodiment, this configuration may be reversed, i.e., the negative electrical wire110is coupled to the proximal end of the heater106while the positive electrical wire108is coupled to the distal end of the heater106. Energy is applied to the heater106from the electrical wires108,110in order to sever the portion of the tether104in the proximity of the heater106. It is not necessary for the heater106to be in direct contact with the tether104. The heater106merely should be in sufficient proximity to the tether104so that heat generated by the heater106causes the tether104to sever. As a result of activating the heater106, the section of the stretch resistant tether104that is approximately distal from the heater106and within the lumen of an implant device112is released from the pusher102along with the implant device112. As illustrated, the implant device112is an embolic coil. An embolic coil suitable for use as the implant device112may comprise a suitable length of wire formed into a helical microcoil. The coil may be formed from a biocompatible material including platinum, rhodium, palladium, rhenium, tungsten, gold, silver, tantalum, and various alloys of these metals, as well as various surgical grade stainless steels. Specific materials include the platinum/tungsten alloy known as Platinum 479 (92% Pt, 8% W, available from Sigmund Cohn, of Mount Vernon, N.Y.) and nickel/titanium alloys (such as the nickel/titanium alloy known as Nitinol). Another material that may be advantageous for forming the coil is a bimetallic wire comprising a highly elastic metal with a highly radiopaque metal. Such a bimetallic wire would also be resistant to permanent deformation. An example of such a bimetallic wire is a product comprising a Nitinol outer layer and an inner core of pure reference grade platinum, available from Sigmund Cohn, of Mount Vernon, N.Y., and Anomet Products, of Shrewsbury, Mass. Commonly-assigned U.S. Pat. No. 6,605,101 provides a further description of embolic coils suitable for use as the implant device112, including coils with primary and secondary configurations wherein the secondary configuration minimizes the degree of undesired compaction of the coil after deployment. The disclosure of U.S. Pat. No. 6,605,101 is fully incorporated herein by reference. Furthermore, the implant device112may optionally be coated or covered with a hydrogel or a bioactive coating known in the art. The coil-type implant device112resists unwinding because the stretch resistant tether104that extends through the lumen of the implant device112requires substantially more force to plastically deform than the implant device112itself. The stretch resistant tether104therefore assists in preventing the implant device112from unwinding in situations in which the implant device112would otherwise unwind. During assembly, potential energy may be stored within the device to facilitate detachment. In one embodiment, an optional spring116is placed between the heater106and the implant device112. The spring is compressed during assembly and the distal end of the tether104may be tied or coupled to the distal end of the implant device112, or may be melted or otherwise formed into an atraumatic distal end114. In one embodiment, the stretch resistant tether104is made from a material such as a polyolefin elastomer, polyethylene, or polypropylene. One end of the tether104is attached to the pusher102and the free end of the tether104is pulled through the implant112with the proximal end of the implant112flush to either the heater106(if no spring116is present) or to the compressed spring116. A pre-set force or displacement is used to pre-tension the tether104, thus storing energy in an axial orientation (i.e. co-linear or parallel to the long axis of the pusher102) within the tether104. The force or displacement depends on the tether material properties, the length of the tether104(which itself depends on the tether's attachment point on the pusher and the length of the implant). Generally, the force is below the elastic limit of the tether material, but sufficient to cause the tether to sever quickly when heat is applied. In one preferred embodiment wherein the implant to be deployed is a cerebral coil, the tether has a diameter within the range of approximately 0.001 to 0.007 inches. Of course the size of the tether can be changed to accommodate different types and sizes of other implants as necessary. Turning toFIG.2, another embodiment of a detachment system of the present invention, detachment system200, is illustrated. Detachment system200shares several common elements with detachment system100. For example, the same devices usable as the implant device112with detachment system100are also usable as the implant device112with detachment system200. These include, e.g., various embolic microcoils and coils. The implant device112has been previously described with respect to detachment system100. As with the implant device112, the same identification numbers are used to identify other elements/components of detachment system100that may correspond to elements/components of detachment system200. Reference is made to the description of these elements in the description of detachment system100as that description also applies to these common elements in detachment system200. With detachment system200, an interior heating element206is used to separate a section of a stretch resistant tube104and an associated implant device112from the detachment system200. Detachment system200includes a delivery pusher202that incorporates a core mandrel218. The detachment system200further includes a positive electrical wire208and a negative electrical wire210that extend through the lumen of the delivery pusher202. To form the internal heating element206, the positive electrical wire208and the negative electrical wire210may be coupled to the core mandrel218of the delivery pusher202. Preferably, the electrical wires208,210are coupled to a distal portion of the core mandrel218. In one embodiment, the positive electrical wire208is coupled to a first distal location on the core wire218, and the negative electrical wire210is coupled to a second distal location on the core wire218, with the second distal location being proximal to the first distal location. In another embodiment, the configuration is reversed, i.e., the positive electrical wire208is coupled to the second distal location and the negative electrical wire210is coupled to the first distal location on the core wire218. When the positive electrical wire208and the negative electrical wire210are coupled to the distal portion of the core mandrel218, the distal portion of the core mandrel218along with the electrical wires208,210forms a circuit that is the interior heating element206. The heater206increases in temperature when a current is applied from a power source (not shown) that is coupled to the positive electrical wire208and the negative electrical wire210. If a greater increase in temperature/higher degree of heat is required or desired, a relatively high resistance material such as platinum or tungsten may be coupled to the distal end of the core mandrel218to increase the resistance of the core mandrel218. As a result, higher temperature increases are produced when a current is applied to the heater206than would be produced with a lower resistance material. The additional relatively high resistance material coupled to the distal end of the core mandrel218may take any suitable form, such as, e.g., a solid wire, a coil, or any other shape or material as described above. Because the heater206is located within the lumen of the tube-shaped tether104, the heater206is insulated from the body of the patient. As a result, the possibility of inadvertent damage to the surrounding body tissue due to the heating of the heater206may be reduced. When a current is applied to the heater206formed by the core mandrel218, the positive electrical wire208, and the negative electrical wire210, the heater206increases in temperature. As a result, the portion of the stretch resistant tether104in proximity to the heater206severs and is detached, along with the implant device112that is coupled to the tether104, from the detachment system200. In one embodiment of the detachment system200, the proximal end of the stretch resistant tether104(or the distal end of a larger tube (not shown) coupled to the proximal end of the stretch resistant tether104) may be flared in order to address size constraints and facilitate the assembly of the detachment system200. In a similar manner as with detachment system100, energy may be stored within the system with, for example, an optional compressive spring116or by pre-tensioning the tether104during assembly as previously described. When present, the release of potential energy stored in the system operates to apply additional pressure to separate the implant device112, and the portion of the stretch resistant tether104to which the implant device112is coupled, away from the heater206when the implant device112is deployed. This advantageously lowers the required detachment time and temperature by causing the tether104to sever and break. As with detachment system100, the distal end of the stretch resistant tether104of detachment system200may be tied or coupled to the distal end of the implant device112, or may be melted or otherwise formed into an atraumatic distal end114. FIG.4illustrates another preferred embodiment of a detachment system300. In many respects, the detachment system300is similar to the detachment system200shown inFIG.2and detachment system100shown inFIG.1. For example, the detachment system300includes a delivery pusher301containing a heater306that detaches an implant device302. Detachment system300also utilizes a tether310to couple the implant device302to the delivery pusher301. In the cross-sectional view ofFIG.4, a distal end of the delivery pusher301is seen to have a coil-shaped heater306that is electrically coupled to electrical wires308and309. These wires308,309are disposed within the delivery pusher301, exiting at a proximal end of the delivery pusher301and coupling to a power supply (not shown). The tether310is disposed in proximity to the heater306, having a proximal end fixed within the delivery pusher301and a distal end coupled to the implant device302. As current is applied through wires308and309, the heater306increases in temperature until the tether310breaks, releasing the implant device302. To reduce the transfer of heat from the heater306to the surrounding tissue of the patient and to provide electrical insulation, an insulating cover304is included around at least the distal end of the outer surface of the delivery pusher301. As the thickness of the cover304increases, the thermal insulating properties also increase. However, increased thickness also brings increased stiffness and a greater diameter to the delivery pusher301that could increase the difficulty of performing a delivery procedure. Thus, the cover304is designed with a thickness that provides sufficient thermal insulating properties without overly increasing its stiffness. To enhance attachment of the tether310to the implant device302, the implant device302may include a collar member322welded to the implant device302at weld318and sized to fit within the outer reinforced circumference312of the delivery pusher301. The tether310ties around the proximal end of the implant device302to form knot316. Further reinforcement is provided by an adhesive314that is disposed around the knot316to prevent untying or otherwise unwanted decoupling. In a similar manner as with detachment systems100and200, energy may be stored within the system with, for example, an optional compressive spring (similar to compressive spring116inFIG.1but not shown inFIG.4) or by axially pre-tensioning the tether104during assembly. In this embodiment, one end of the tether310is attached near the proximal end of the implant device302as previously described. The free end of the tether310is threaded through a distal portion of the delivery pusher301until it reaches an exit point (not shown) of the delivery pusher301. Tension is applied to the tether310in order to store energy in the form of elastic deformation within the tether material by, for example, placing a pre-determined force on the free end of the tether310or moving the taut tether310a pre-determined displacement. The free end of the tether310is then joined to the delivery pusher301by, for example, tying a knot, applying adhesive, or similar methods known in the art. When present, the release of potential energy stored in the system operates to apply additional pressure to separate the implant device302, and the portion of the tether310to which the implant device302is coupled, away from the heater306when the implant device302is deployed. This advantageously lowers the required detachment time and temperature by causing the tether310to sever and break. The present invention also provides for methods of using detachment systems such as detachment systems100,200, or300. The following example relates to the use of detachment system100,200, or300for occluding cerebral aneurysms. It will, however, be appreciated that modifying the dimensions of the detachment system100,200, or300and the component parts thereof and/or modifying the implant device112,302configuration will allow the detachment system100,200, or300to be used to treat a variety of other malformations within a body. With this particular example, the delivery pusher102,202, or301of the detachment system100,200, or300may be approximately 0.010 inches to 0.030 inches in diameter. The tether104,310that is coupled near the distal end of the delivery pusher102,202, or301and is coupled to the implant device112,302may be 0.0002 inches to 0.020 inches in diameter. The implant device112,302; which may be a coil, may be approximately 0.005 inches to 0.020 inches in diameter and may be wound from 0.0005 inch to 0.005 inch wire. If potential energy is stored within the detachment system100,200, or300, the force used to separate the implant device112,302typically ranges up to 250 grams. The delivery pusher102,202, or301may comprise a core mandrel218and at least one electrically conductive wire108,110,208,210,308, or309. The core mandrel218may be used as an electrical conductor, or a pair of conductive wires may be used, or a bipolar wire may be used as previously described. Although the detachment systems100,200, and300have been illustrated as delivering a coil, other implant devices are contemplated in the present invention. For example,FIG.8illustrates the detachment system300as previously described inFIG.4having an implant that is a stent390. This stent390could similarly be detached by a similar method as previously described in regards to the detachment systems100,200, and300. In a further example, the detachment systems100,200, or300may be used to deliver a filter, mesh, scaffolding or other medical implant suitable for delivery within a patient. FIG.7presents an embodiment of a delivery pusher350, which could be used in any of the embodiments as delivery pusher102,202, or301, which includes radiopaque materials to communicate the position of the delivery pusher350to the user. Specifically, the radiopaque marker material is integrated into the delivery pusher350and varied in thickness at a desired location, facilitating easier and more precise manufacturing of the final delivery pusher350. Prior delivery pusher designs, such as those seen in U.S. Pat. No. 5,895,385 to Guglielmi, rely on high-density material such as gold, tantalum, tungsten, or platinum in the form of an annular band or coil. The radiopaque marker is then bonded to other, less dense materials, such as stainless steel, to differentiate the radiopaque section. Since the radiopaque marker is a separate element placed at a specified distance (often about 3 cm) from the tip of the delivery pusher, the placement must be exact or the distal tip of the delivery pusher350can result in damage to the aneurysm or other complications. For example, the delivery pusher350may be overextended from the microcatheter to puncture an aneurysm. Additionally, the manufacturing process to make a prior delivery pusher can be difficult and expensive, especially when bonding dissimilar materials. The radiopaque system of the present invention overcomes these disadvantages by integrating a first radiopaque material into most of the delivery pusher350while varying the thickness of a second radiopaque material, thus eliminating the need to bond multiple sections together. As seen inFIG.7, the delivery pusher350comprises a core mandrel354(i.e. the first radiopaque material), preferably made from radiopaque material such as tungsten, tantalum, platinum, or gold (as opposed to the mostly radiolucent materials of the prior art designs such as steel, Nitinol, and Elgiloy). The delivery pusher350also includes a second, outer layer352, having a different radiopaque level. Preferably, outer layer352is composed of a material having a lower radiopaque value than the core mandrel354, such as Elgiloy, Nitinol, or stainless steel (commercially available from Fort Wayne Metals under the trade name DFT). In this respect, both the core mandrel354and the outer layer352are visible and distinguishable from each other under fluoroscopy. The outer layer352varies in thickness along the length of the delivery pusher350to provide increased flexibility and differentiation in radio-density. Thus the thicker regions of the outer layer352are more apparent to the user than the thinner regions under fluoroscopy. The transitions in thickness of the outer layer352can be precisely created at desired locations with automated processes such as grinding, drawing, or forging. Such automated processes eliminate the need for hand measuring and placement of markers and further eliminates the need to bond a separate marker element to other radiolucent sections, thus reducing the manufacturing cost and complexity of the system. In the present embodiment, the delivery pusher350includes three main indicator regions of the outer layer352. A proximal region356is the longest of the three at 137 cm, while a middle region358is 10 cm and a distal region360is 3 cm. The length of each region can be determined based on the use of the delivery pusher350. For example, the 3 cm distal region360may be used during a coil implant procedure, as known in the art, allowing the user to align the proximal edge of the distal region360with a radiopaque marker on the microcatheter within which the delivery pusher350is positioned. The diameter of each of the regions depends on the application and size of the implant. For a typical cerebral aneurysm application for example, the proximal region356may typically measure 0.005-0.015 inches, the middle region358may typically measure 0.001-0.008 inches, while the distal region360may typically measure 0.0005-0.010 inches. The core mandrel354will typically comprise between about 10-80% of the total diameter of the delivery pusher350at any point. Alternately, the delivery pusher350may include any number of different regions greater than or less than the three shown inFIG.7. Additionally, the radiopaque material of the core mandrel354may only extend partially through the delivery pusher350. For example, the radiopaque material could extend from the proximal end of the core mandrel354to three centimeters from the distal end of the delivery pusher350, providing yet another predetermined position marker visible under fluoroscopy. In this respect, the regions356,358, and360of delivery pusher350provide a more precise radiopaque marking system that is easily manufactured, yet is readily apparent under fluoroscopy. Further, the increased precision of the markers may decrease complications relating to improper positioning of the delivery pusher during a procedure. In operation, the microcatheter is positioned within a patient so that a distal end of the microcatheter is near a target area or lumen. The delivery pusher350is inserted into the proximal end of the microcatheter and the core mandrel354and outer layer352are viewed under fluoroscopy. The user aligns a radiopaque marker on the microcatheter with the beginning of the distal region360, which communicates the location of the implant112,302relative to the tip of the microcatheter. In some situations, for example, small aneurysms where there may be an elevated risk of vessel damage from the stiffness of the delivery pusher350, the user may position the proximal end of the implant slightly within the distal end of the microcatheter during detachment. The user then may push the proximal end of the implant112,302out of the microcatheter with the next coil, an adjunctive device such as guidewire, or the delivery pusher102,202,301, or350. In another embodiment, the user may use the radiopaque marking system to locate the distal end of the delivery pusher outside the distal end of the microcatheter. Once the implant device112,302of the detachment system100,200, or300is placed in or around the target site, the operator may repeatedly reposition the implant device112,302as necessary or desired. When detachment of the implant device112,302at the target site is desired, the operator applies energy to the heater106,206, or306by way of the electrical wires108,110,208,210,308, or309. The electrical power source for the energy may be any suitable source, such as, e.g., a wall outlet, a capacitor, a battery, and the like. For one aspect of this method, electricity with a potential of approximately 1 volt to 100 volts is used to generate a current of 1 milliamp to 5000 milliamps, depending on the resistance of the detachment system100,200, or300. One embodiment of a connector system400that can be used to electrically couple the detachment system100,200, or300to the power source is shown inFIG.6. The connector system400includes an electrically conductive core mandrel412having a proximal end surrounded by an insulating layer404. Preferably the insulating layer404is an insulating sleeve such as a plastic shrink tube of polyolefin, PET, Nylon, PEEK, Teflon, or polyimide. The insulating layer404may also be a coating such as polyurethane, silicone, Teflon, paralyene. An electrically conductive band406is disposed on top of the insulating layer404and secured in place by molding bands414, adhesive, or epoxy. Thus, the core mandrel412and the conductive band406are electrically insulated from each other. The conductive band406is preferably composed of any electrically conductive material, such as silver, gold, platinum, steel, copper, conductive polymer, conductive adhesive, or similar materials, and can be a band, coil, or foil. Gold is especially preferred as the conductive material of the conductive band406because of the ability of gold to be drawn into a thin wall and its ready availability. The core mandrel412has been previously described and may be plated with, for example, gold, silver, copper, or aluminum to enhance its electrical conductivity. The connector system400also includes two electrical wires408and410which connect to the conductive band406and core member412, respectively, and to a heating element at the distal end of a delivery system such as those described inFIGS.1,2, and4(not shown inFIG.6). These wires408and410are preferably connected by soldering, brazing, welding, laser bonding, or conductive adhesive, or similar techniques. Once the user is ready to release the implant112,302within the patient, a first electrical clip or connector from a power source is connected to a non-insulated section402of the core mandrel412and a second electrical clip or connector from the power source is connected to the conductive band406. Electrical power is applied to the first and second electrical clips, forming an electrical circuit within the detachment system100,200, or300, causing the heater106,206, or306to increase in temperature and sever the tether104,310. Once the detachment system100,200, or300is connected to the power source the user may apply a voltage or current as previously described. This causes the heater106,206, or306to increase in temperature. When heated, the pre-tensioned tether104,310will tend to recover to its unstressed (shorter) length due to heat-induced creep. In this respect, when the tether104,310is heated by the heater106,206, or306; its overall size shrinks. However, since each end of the tether104,310is fixed in place as previously described, the tether104,310is unable to shorten in length, ultimately breaking to release the implant device112,302. Because there is tension already within the system in the form of a spring116or deformation of the tether material104,310; the amount of shrinkage required to break the tether104,310is less than that of a system without a pre-tensioned tether. Thus, the temperature and time required to free the implant device112,302is lower. FIG.5is a graph showing the temperatures at the surface of the PET cover304of the detachment system300. As can be seen, the surface temperature of the detachment system300during detachment does not vary linearly with time. Specifically, it only takes just under 1 second for the heat generated by the heating coil306to penetrate the insulating cover304. After 1 second, the surface temperature of the insulating cover304dramatically increases. Although different outer insulating material may slightly increase or decrease this 1-second surface temperature window, the necessarily small diameter of the detachment system100,200, or300prevents providing a thick insulating layer that may more significantly delay a surface temperature increase. It should be understood that the embodiments of the detachment system100,200, or300include a variety of possible constructions. For example, the insulating cover304may be composed of Teflon, PET, polyamide, polyimide, silicone, polyurethane, PEEK, or materials with similar characteristics. In the embodiments100,200, or300the typical thickness of the insulating cover is 0.0001-0.040 inches. This thickness will tend to increase when the device is adapted for use in, for example, proximal malformations, and decrease when the device is adapted for use in more distal, tortuous locations such as, for example, cerebral aneurysms. In order to minimize the damage and possible complications caused by such a surface temperature increase, the present invention detaches the implant device112,302before the surface temperature begins to significantly increase. Preferably, the implant device112,302is detached in less than a second, and more preferably, in less than 0.75 seconds. This prevents the surface temperature from exceeding 50° C. (122° F.), and more preferably, from exceeding 42° C. (107° F.). Once the user attempts to detach the implant device112,302, it is often necessary to confirm that the detachment has been successful. The circuitry integrated into the power source may be used to determine whether or not the detachment has been successful. In one embodiment of the present invention an initial signaling current is provided prior to applying a detachment current (i.e. current to activate the heater106,206, or306to detach an implant112,302). The signaling current is used to determine the inductance in the system before the user attempts to detach the implant and therefore has a lower value than the detachment current, so as not to cause premature detachment. After an attempted detachment, a similar signaling current is used to determine a second inductance value that is compared to the initial inductance value. A substantial difference between the initial inductance and the second inductance value indicates that the implant112,302has successfully been detached, while the absence of such a difference indicates unsuccessful detachment. In this respect, the user can easily determine if the implant112,302has been detached, even for delivery systems that utilize nonconductive temperature sensitive polymers to attach an implant, such as those seen inFIGS.1,2, and4. In the following description and examples, the terms “current” and “electrical current” are used in the most general sense and are understood to encompass alternating current (AC), direct current (DC), and radiofrequency current (RF) unless otherwise noted. The term “changing” is defined as any change in current with a frequency above zero, including both high frequency and low frequency. When a value is measured, calculated and/or saved, it is understood that this may be done either manually or by any known electronic method including, but not limited to, an electronic circuit, semiconductor, EPROM, computer chip, computer memory such as RAM, ROM, or flash; and the like. Finally, wire windings and toroid shapes carry a broad meaning and include a variety of geometries such as circular, elliptical, spherical, quadrilateral, triangular, and trapezoidal shapes. When a changing current passes through such objects as wire windings or a toroid, it sets up a magnetic field. As the current increases or decreases, the magnetic field strength increase or decreases in the same way. This fluctuation of the magnetic field causes an effect known as inductance, which tends to oppose any further change in current. Inductance (L) in a coil wound around a core is dependant on the number of turns (N), the cross-sectional area of the core (A), the magnetic permeability of the core (μ), and length of the coil (I) according to equation 1 below: L=0.4πN2AμIEquation 1 The heater106or306is formed from a wound coil with proximal and distal electrically conductive wires108,110,308, or309attached to a power source. The tether104,310has a magnetic permeability μ1 and is positioned through the center of the resistive heater, having a length l, cross sectional area A, and N winds, forming a core as described in the previous equation. Prior to detachment, a changing signaling current i1, such as the waveforms shown inFIGS.3A and3B, with frequency f1, is sent through the coil windings. This signaling current is generally insufficient to detach the implant. Based on the signaling current, the inductive resistance XL (i.e. the electrical resistance due to the inductance within the system) is measured by an electronic circuit such as an ohmmeter. The initial inductance of the system L1 is then calculated according to the formula: L1=XL 2πf1Equation 2 This initial value of the inductance L1 depends on the magnetic permeability μ1 of the core of the tether104,310according to Equation 1, and is saved for reference. When detachment is desired, a higher current and/or a current with a different frequency than the signaling current is applied through the resistive heater coil, causing the tether104,310to release the implant112,302as previously described. If detachment is successful, the tether104,310will no longer be present within the heater106,306and the inside of the heater106,306will fill with another material such as the patient's blood, contrast media, saline solution, or air. This material now within the heater core will have a magnetic permeability μ2 that is different than the tether core magnetic permeability μ1. A second signaling current and frequency f2 is sent through the heater106,306and is preferably the same as the first signaling current and frequency, although one or both may be different without affecting the operation of the system. Based on the second signaling current, a second inductance L2 is calculated. If the detachment was successful, the second inductance L2 will be different (higher or lower) than the first inductance L1 due to the difference in the core magnetic permeabilities μ1 and μ2. If the detachment was unsuccessful, the inductance values should remain relatively similar (with some tolerance for measurement error). Once detachment has been confirmed by comparing the difference between the two inductances, an alarm or signal can be activated to communicate successful detachment to the user. For example, the alarm might include a beep or an indicator light. Preferably, the delivery system100,300used according to this invention connects to a device that automatically measures inductance at desired times, performs required calculations, and signals to the user when the implant device has detached from the delivery catheter. However, it should be understood that part or all of these steps can be manually performed to achieve the same result. The inductance between the attached and detached states can also preferably be determined without directly calculating the inductance. For example, the inductive resistance XL can be measured and compared before and after detachment. In another example, the detachment can be determined by measuring and comparing the time constant of the system, which is the time required for the current to reach a predetermined percentage of its nominal value. Since the time constant depends on the inductance, a change in the time constant would similarly indicate a change in inductance. The present invention may also include a feedback algorithm that is used in conjunction with the detachment detection described above. For example, the algorithm automatically increases the detachment voltage or current automatically after the prior attempt fails to detach the implant device. This cycle of measurement, attempted detachment, measurement, and increased detachment voltage/current continues until detachment is detected or a predetermined current or voltage limit is attained. In this respect, a low power detachment could be first attempted, followed automatically by increased power or time until detachment has occurred. Thus, battery life for a mechanism providing the detachment power is increased while the average coil detachment time is greatly reduced. Referring now toFIGS.9and10, there is shown an embodiment of a delivery system500for use with the present invention that includes a detachment detection capability. The delivery system500operates under the principle that electrical current passing through a coil held in an expanded, open gap configuration will encounter more resistance than electrical current passing through a coil in a contracted, closed gap configuration. In the expanded configuration, the electrical current must follow the entire length of the coiled wire. In the contracted configuration, the electrical current can bridge the coils and travel in a longitudinal direction. The delivery system500is generally similar to the previously described detachment system300of the present invention seen inFIG.4, including a delivery pusher301, containing a heater coil306that detaches an implant device302. The detachment system500similarly utilizes a tether310to coupled the implant device302to the delivery pusher301. The heater coil306is preferably a resistance-type heater having a plurality of loops306A as seen inFIG.10, that connects to a voltage source through a connector system at the proximal end of the delivery pusher301, such as the connector system400described inFIG.6. The delivery system500also includes a heater coil expander502that serves two functions. First, it expands the heater coil306such that the heater coil306maintains a friction-fit attachment to the inside of the insulating cover309, thereby connecting the two. Second, the heater coil expander502expands the heater coil306in such a manner that electricity is forced to flow around each individual loop306A of the coil306in order to maximize the resistance of the coil306. Maximizing the coil resistance not only serves to heat the coil306when voltage is passed through, it also sets an initial value (or “normal” value) for the resistance provided by the coil306, which can be used to compare a changed resistance state, indicating detachment of the implant302. Hence, the heater coil expander502must also be capable of undergoing change when subjected to heat. In this regard, the heater coil expander502may be made of any suitable sturdy material capable of holding the heater coil306in an expanded, biased state while also being capable of melting or being otherwise reduced by the heat of the heater coil306in order to yield to the bias of the heater coil306to return to an unbiased state. Examples of acceptable materials include, but are not limited to, polymers and monofilament. The heater coil expander502shown inFIGS.9and10operates by longitudinally, or radially and longitudinally, expanding a heater coil306which is normally a closed gap coil in a relaxed state. In other words, the individual loops306A contact each other when the heater coil306is not stretched or radially expanded. Preferably, the heater coil expander502may have a coiled shape, similar to the heater coil306and as seen inFIG.10. Alternately, the heater coil expander may have a continuous, tubular shape with helical ridges similar to the individual coil shapes of the expander502inFIG.10. It should be understood that a variety of different expander shapes that expand the loops or coils306A of the heater coil306from each other. Preferably the power source (previously described in this embodiment and connected to the connector system400) also includes a measuring instrument for measuring the resistance of the heater coil306. In this respect, the power source (preferably located in a hand-sized unit) includes an indicator that communicates when a change in resistance has occurred and therefore when detachment of the implant has occurred. An alternative embodiment of the heater coil expander512is shown inFIGS.10and11. The heater coil expander512operates in conjunction with the heater coil306so that the heater loops are in an open gap state (FIG.10), and a pusher350, as previously described inFIG.7, that conducts electricity. The heater coil306is sized to snugly fit around the pusher350in a contracted state. The heater coil expander512operates to separate the heater coil306from the pusher350, electrically isolating the heater coil306therefrom. As the heat from the heater coil306melts or otherwise reduces or degrades the heater coil expander512, the heater coil306resumes a contracted state (i.e., reduced diameter configuration), making electrical, if not physical, contact with the pusher350(FIG.11). In this respect the individual loops are shortened, significantly reducing the resistance of the circuit and thereby indicating detachment has occurred. Another alternative embodiment of the present invention, the heater coil expander502may be sized to expand the heater coil306against the conductive reinforcement circumference312(shown inFIG.9). Hence, when the coil306is in its initial expanded position, the electrically conductive reinforcement circumference312maintains a low initial resistance that is registered by the controller for the circuit (i.e., the measurement device of the power source). When the heater coil306is energized, the initial resistance is noted and the heater coil expander306melts, degrades or otherwise reduces. The heater coil306then contracts, releasing the attachment tube (and the rest of the implant510) and the heater coil306is no longer shorted out by the reinforcement circumference312. Thus, the circuit experiences a change in resistance as the electrical current must travel through each of the individual loops. This increase in resistance signifies the implant302is detached. FIGS.13-16illustrate another preferred embodiment of a delivery system600according to the present invention. For illustrative purposes, it should be noted that the outer body of the system600is not shown. The delivery system600is generally similar to some of the previously described embodiments, in that it includes a tether606that secures an implantable device612to the delivery system600and a heater coil604that causes the tether606to break, thereby releasing the implantable device612. However, as seen in these Figures, the heater coil604is sized with a diameter that is much smaller than previous embodiments. More specifically, the heater coil604preferably has an internal passage that is only slightly larger in diameter than the outer diameter of the tether606. In other words, the internal diameter of the heater coil604is substantially the same as the outer diameter of the tether604. According to one embodiment, the internal passage of the heating coil604solely contains the tether606. According to another embodiment, the diameter of the internal passage may be large enough for only the tether606to pass through. In another embodiment, the diameter may be large enough for only the tether and other components, such as support mandrel611or electrical wires608and610. In either case, at least a portion of the internal diameter of the heater coil604maintains a close proximity to the tether606, allowing the tether606to pass through once. Additionally, the heater coil604preferably includes a smaller diameter region604A which is positioned closer to the tether606than the remaining portions of the coil604. In this respect, the region604A can more efficiently transfer heat to the tether606and therefore break the tether with an otherwise lower temperature than without the region604A. Providing a lower temperature reduces the risk of damaging the patient's tissue surrounding the system600. In a specific example, the heater coil604has an internal diameter of about 0.007 inch and an internal diameter of about 0.005 inch at region604A while the tether606has an external diameter of about 0.004 inch. As in previously described embodiments, the heater coil604may be composed of a coiled heating element wire. However, it should be understood that other heater configurations are possible, such as a solid, conducting tube or a wire arranged in a non-coiled shape, such as a wave or undulating pattern that forms an overall tubular shape (that may not completely surround the tether606). Both ends of the tether606are preferably secured to an outer structural coil602of the delivery device600. For example, the ends of the tether606can be tied, glued (e.g., with U.V. cured adhesive), welded or clamped. It should be understood that the ends of the tether606can be secured at almost any location along the length of the structural coil602, as long as those locations allow at least a portion of the tether606to pass through the heater coil604. For example, both ends of the tether606can be secured proximal to the heater coil604. In another example, one end of the tether can be secured proximal to heater coil604and another end can be secured distal to the heater coil604. As seen inFIGS.13,16, and17, the tether606preferably passes through openings, cells, loops or other structures of the implantable device612. For example, the tether606may pass through cells of a stent. As seen inFIG.16, the tether606can pass through multiple cells of the device612and is maintained under tension as seen inFIGS.13and17. The tension of the tether606keeps the device612in a compressed state (i.e., compressed in diameter) and abutted to the distal end of the system600(e.g., the distal end of the outer body member609). In this respect, when the tether606is broken by the heater coil604, the tether606unwraps from the device612and stays with the delivery system600, not the device612. Hence, the tether606does not remain in the patient to potentially cause unwanted complications. As with previously described embodiments, the delivery system600is connectable to a selectively actuated power supply (e.g., via a button on a handle of the delivery device600). Wires608and610deliver electric current to the heater coil604at a desired time, causing the coil604to heat and thereby break the tether606. Preferably, the heater coil604is supported within the delivery system600by a support mandrel611(best seen inFIG.15) that extends along a length of the system600. Preferably, the support mandrel611is secured to the heater coil604by welding, adhesive or a mechanical interlocking arrangement (not shown). The proximal end of the support mandrel611is preferably attached to a core wire or delivery pusher (e.g., pusher350described in other embodiments in this specification). The outer coil602provides support to the delivery system and can be positioned on the inside of a lumen of the delivery system body609(seeFIG.17). Alternately, this coil602can be positioned between material layers of the delivery system body609(not shown) or otherwise embedded in the material of the delivery system body609. In operation, a distal end of the delivery system600is positioned at a target location within a patient. When the implantable device612(e.g., catheter, valve or microcoil) has achieved a desired position, the user provides electric current to the heater coil604(e.g., via a button on the delivery device600). The heater coil604, including section604A, increases in temperature, causing the tether606to break. The tether606, previously under tension, passes through the cells or attachment points of the implantable device612releasing the device612from the delivery system600. The delivery system600can then be removed from the patient, along with the attached tether606. It should be understood that other tether arrangements are possible according to the present invention. For example,FIG.18illustrates the use of three tethers614A,614B and614C which attach to different locations on the device612. Preferably, these tethers614A,614B and614C have a smaller diameter than the previously described tether606. In the present preferred embodiment, the tethers614A,614B and614C are tied to the device612at knots616. However, adhesives, clamps and other attachment arrangements are also possible. While not shown in the Figures, each tether614A,614B and614C can be looped through a portion of the device612, similar to the single tether of previously described embodiments and attached to a location in the delivery system600. Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. For example, the heater coil or heater coil expander could be constructed to activate a switch that provides a user indication of detachment in some manner. Additionally, a visual indicator may be associated with the change in resistance to provide easy indication of detachment. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof.

11857197

DETAILED DESCRIPTION The present technology is generally directed to implantable medical devices and, in various aspects, to systems and methods for invasively adjusting implantable devices for selectively controlling fluid flow between a first body region and a second body region of a patient. For example, in many of the embodiments described herein, a catheter or other elongated body can be used to mechanically, thermally, and/or electrically engage an implanted medical device. Once the catheter engages the medical device, the catheter can (i) increase a dimension associated with the medical device, such as through mechanical expansion forces, and/or (ii) decrease a dimension associated with the medical device, such as by heating a shape memory component of the medical device above a phase transition temperature. For example, in some embodiments the present technology includes a system comprising a shunt configured to be implanted in a patient to fluidly couple the first body region and the second body region, and an energy delivery catheter configured to selectively adjust a dimension or parameter of the shunt. The shunt can include a flowpath that permits fluid to flow through the shuntbetween the first and second body regions. The shunt can also include an actuation section with a shape memory actuation component that is bi-directionally adjustable along at least one dimension. The catheter can include an expandable member for engaging the shunt, and one or more energy delivery elements configured to heat the shape memory component when the expandable member is in an expanded configuration. In some embodiments, the shape memory component, when heated via the one or more energy delivery elements, undergoes a material phase transformation that induces a geometric change in the shape memory component and changes a dimension of the flowpath. The terminology used in the description presented below is intended to be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain specific embodiments of the present technology. Certain terms may even be emphasized below; however, any terminology intended to be interpreted in any restricted manner will be overtly and specifically defined as such in this Detailed Description section. Additionally, the present technology can include other embodiments that are within the scope of the examples but are not described in detail with respect toFIGS.1-19. Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present technology. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features or characteristics may be combined in any suitable manner in one or more embodiments. Reference throughout this specification to relative terms such as, for example, “generally,” “approximately,” and “about” are used herein to mean the stated value plus or minus 10%. As used herein, the term “shunt” is used to refer to a device that, in at least one configuration, can provide a fluid flow (e.g., blood flow) between a first region (e.g., a LA of a heart) and a second region (e.g., a RA or coronary sinus of the heart) of a patient. Although certain embodiments herein are described in terms of a shunt between the atria, namely the left and right atria, one will appreciate that the technology may be applied equally to devices positioned between other chambers and passages of the heart, between other parts of the cardiovascular system, or other parts of a patient's body. For example, any of the shunts described herein, including those referred to as “interatrial,” may be nevertheless used and/or modified to shunt between the LA and the coronary sinus, between the right pulmonary vein and the superior vena cava, or between other body regions. Moreover, while the disclosure herein primarily describes shunting blood from the LA to the RA, the present technology can be readily adapted to shunt blood from the RA to the LA to treat certain conditions, such as pulmonary hypertension. For example, mirror images of embodiments, or in some cases identical embodiments, used to shunt blood from the LA to the RA can be used to shunt blood from the RA to the LA in certain patients. The headings provided herein are for convenience only and do not interpret the scope or meaning of the claimed present technology. A. Select Embodiments of Systems and Methods for Selectively Adjusting Implantable Devices FIG.1is a simplified block diagram of a medical system101(“system101”) configured in accordance with an embodiment of the present technology. More specifically, system101is configured to enable bi-directional adjustment of a geometric dimension of an implantable device. In the figure, select components of the system101are denoted by solid boxes and optional system components are denoted by dashed boxes, although one skilled in the art will appreciate the system101can include any combination of the foregoing components. The system101can contain two main subsystem components, an implanted device102(e.g., a shunt, an occluder, a hemodynamic monitor, etc.) and an energy delivery device103(e.g., a catheter system, an energy delivery apparatus, an external transmitter, a subcutaneous implant, etc.). The implanted device102contains an actuator complex104. The actuator complex104may be comprised of multiple components, at least one of which is bi-directionally adjustable along at least one dimension. In some implementations, the actuator complex104contains a component that has a radially-adjustable geometry (i.e., can be configured to change diameter, cross-sectional area, and/or another similar parameter). Within examples, the implanted device102of system101can contain additional components or features. Some implementations may include a docking or interface feature107(e.g, a groove, notch, magnet, tether, or another interface known to those skilled in the art) intended to facilitate the coupling of the implanted device102with an energy delivery device103. Implementations of the implanted device102may also include one or more size measurement components106intended to measure and/or transmit/display a geometric dimension associated with the actuator complex104. The implanted device102may optionally be comprised of additional device components105, which in examples may include anchoring or stabilization features, structural components such as frames or scaffolds, sensing or diagnostic components, electronic components, or other components known in the art. The system101also contains an energy delivery device103intended to interface with the implanted device102at a time following the initial implantation/placement of the device. The energy delivery device103contains an energy delivery system108which is capable of conveying energy to the actuator complex104of the implanted device102. Within examples, the energy delivery system108is comprised of at least two components: an energy source109and an energy coupling mechanism110which facilitates the transmission of energy from the energy source109to the actuator complex104. In some implementations the energy source109and energy coupling mechanism110may take the form of a single component. In variation implementations the energy coupling mechanism110may be omitted and the energy source109may interface with the actuator complex104directly. In some implementations, the energy delivery system108may contain additional components (e.g., various electrical components and/or mechanical controls). The energy delivery system108, whether composed of a single component or multiple components, can also be referred to herein as an energy delivery device and/or an energy delivery element. Within examples, the energy delivery device103may contain additional components or features. Some implementations may include a docking or interface feature113(e.g., a groove, notch, magnet, tether, or another interface known to those skilled in the art) intended to facilitate coupling to the implanted device102. The docking or interface feature113may be stand-alone or may form a portion of an interface complex with a complementary docking or interface feature107that is located on the implanted device102. Implementations of the energy delivery device103can also include one or more actuator adjustment systems112that are intended to alter the geometry of at least a portion of the actuator complex104without the use of the energy source109. Within examples, the actuator adjustment system112may be co-located or integral with an energy delivery system108. In implementations, an energy delivery device103may contain an actuator adjustment system112and an energy delivery system108that work complementary to one another; for example, the energy delivery system108may adjust a geometry of the actuator complex104in a first direction and the actuator adjustment system112may adjust the actuator complex104in a second direction that is different than the first direction. In some implementations, the changes in actuator complex104geometry induced by the energy delivery system108may be reversed by the actuator adjustment system112, and/or vice-versa. The energy delivery device103can be comprised of additional device components111, which in selected implementations may include guidewires, sheaths, steering components, handles, buttons, switches, toggles and other user interface features, power sources, lumens, injection ports, sensors and related electronics, imaging components, or other components known in the art. FIG.2is a block diagram illustrating a method (“method200”) for adjusting a medical system in accordance with embodiments of the present technology. The method200can be utilized in conjunction with system101(FIG.1) or other suitable medical systems. Beginning at step201, the method200can involve interfacing an energy delivery device (e.g., device103) with an implanted medical device (e.g., device102). A second step202can involve using an energy delivery system (e.g., system108) on the energy delivery device to adjust a geometry of an actuator complex (e.g., complex104) on the implanted device from a first geometry to a second geometry in a manner that is reversible (e.g., an adjustment that makes part of an actuator complex smaller can later be undone, returning the part of the actuator complex to its larger pre-adjustment size). A third step203can involve decoupling the energy delivery device from the implanted medical device in a manner such that actuator complex remains in a geometry that is altered from the first geometry, and removing the energy delivery device from the body. FIG.3is a block diagram illustrating a method (“method300”) for adjusting a medical system in accordance with another embodiment of the present technology. The method300can be utilized in conjunction with system101(FIG.1) or other suitable medical systems. Beginning at step301, the method300can involve interfacing an energy delivery device (e.g., device103) with an implanted medical device (e.g., device102) that includes an actuator complex (e.g., complex104) having an initial geometry. A second step302can involve using an energy delivery system (e.g., system108) on the energy delivery device to adjust a dimension of the actuator complex on the implanted device in a first direction. In some embodiments, the second step302includes adjusting a dimension of the actuator complex in a first direction to and/or toward a minimum dimension. A third step303can involve using the energy delivery device to make a second adjustment of a dimension of the actuator complex on the implanted device in a second, opposite direction. In some implementations of the method, steps302and303may be repeated multiple times (e.g., subsequently performed back and forth to arrive at a desirable geometry before proceeding to an additional step). A fourth step304can involve decoupling the energy delivery device from the implanted medical device in a manner such that actuator complex remains in a geometry that is altered from the initial geometry, and removing the delivery device from the body. Method300takes advantage of the novel bi-directional adjustment features enabled by the present technology described herein. An advantage of method300is that it can allow for more precise adjustments of a dimension of a medical device by always returning to a known actuator geometry (e.g., via step302, returning an actuator to a minimum dimension) prior to making a subsequent adjustment. An additional advantage of method300is that a geometry of an implanted device can be both compressed or enlarged, which is not generally possible with current devices known in the art. FIG.4is a simplified block diagram of an implementation that may be instituted in connection with system101, according to examples of the present disclosure. More specificallyFIG.4illustrates a simplified block diagram of a medical system401(“system401”) that includes an implantable cardiac shunt402(e.g., an interatrial shunt) and a catheter device403(e.g., an elongated energy delivery catheter) configured to interface with the implanted shunt at a time during or following implantation. Though not shown, system401may contain additional components and sub-systems, for example a delivery catheter device for initial implantation of the device into the body of a patient. In the figure, select components of the system401are denoted by solid boxes and optional system components are denoted by dashed boxes, although one skilled in the art will appreciate the system401can include any combination of the foregoing components. It should be understood that any components of system401can be present in any number of quantities. For example, there may be a single instance of a component or a plurality of the component, regardless of how the component is described inFIG.4. An implanted cardiac shunt402can be utilized to fluidly connect two regions of the cardiovascular system, for example two chambers of the heart. For example, the shunt may be an interatrial shunt that is implanted on to or into the atrial septum to fluidly connect the left atrium (LA) and right atrium (RA). An implementation of the cardiac shunt402includes a frame407that provides structure to the device and, in some examples, interfaces with a septal wall. The frame407may have a lattice or stent-like design and be comprised of a biocompatible material such as nitinol, stainless steel, a polymer, or other materials known to those skilled in the art. The frame407may hold a hole or opening that has been created in a septal wall patent and in a fixed geometry and therefore define at least a portion of the fluid communication pathway or orifice between the LA and the RA. The cardiac shunt402can also include one or more frame membranes408that interfaces with the shunt frame407and optionally other aspects of the device. The frame membrane(s)408may line, envelop, or otherwise join with the frame407to establish a flow lumen between the LA and the RA. The membrane may be comprised of a material such as expanded polytetrafluoroethylene (ePTFE), polyethylene terephthalate (PET) (e.g., sold under the trademark DACRON), polycarbonate urethane, silicone, nylon, latex, or another material. In applications, it may be desired for the membrane material to be biocompatible, non-thrombogenic, substantially fluid impermeable, elastic/flexible, and resistant to damage, tearing, wear, etc. The cardiac shunt402can also include anchoring or stabilization features409that help maintain the position of the device, for example to keep the shunt attached to, integrated into, or otherwise interfaced with the septal wall. Anchors may take the form of spirals, tines, coils, meshes, or other features that are integral to or attach to the frame407and interface with tissue in the region of implantation. Stabilization features may be used to hold the cardiac shunt402in place without applying meaningful forces to a septal wall, and may take the form of flared or trumpeted sections of the device that become larger in diameter than the septal opening, thereby preventing portions of the deployed device from migrating back through the septal opening to an undesired location. Within examples, there may be a plurality of anchoring or stabilization features409, for example features on both the LA and RA sides of a septal wall. In such implementations, a first anchoring or stabilization feature may differ from additional anchoring or stabilization features found elsewhere on the cardiac shunt402. The cardiac shunt402also includes an actuation section404that is bi-directionally adjustable along at least one dimension. Within examples, the actuation section404includes both a shape memory component405and a membrane406. In some implementations, the membrane406may be similar to, identical to, or contiguous with frame membrane408. The shape memory component405may be comprised of nitinol or a similar metallic alloy or polymer that has been manufactured to have a material phase transition or glass transition temperature (e.g., an austenite start temperature, an austenite finish temperature, etc.) that is higher than body temperature. As described in detail in the examples provided below, the shape memory component405is configured to be adaptable to a plurality of geometric configurations, and can be adjusted bidirectionally (i.e., in at least one dimension, it can be both increased from a smaller geometry to a larger geometry and decreased from a larger geometry to a smaller geometry). In implementations, the shape memory component405can be adjusted radially and therefore a diameter of a generally circular or ovular cross-section defined by the shape memory component can be altered. In implementations, some geometric adjustments (e.g., those below the plastic strain limit) to the shape memory component405are reversible (e.g., after the shape memory component has been adjusted from a smaller geometry to a larger geometry, it can be further adjusted to regain the smaller geometry). Within examples, the membrane406can be utilized to give structure to the actuation section404of the cardiac shunt402, defining the fluid transmission pathway through this section404. In implementations, the membrane406can be utilized as a means to mechanically join the actuation section404to the shunt frame407. In other implementations, the membrane406may serve as part of a complex that mechanically joins or otherwise operably couples the actuation section404to the shunt frame407. In some implementations, the shunt frame407, frame membrane408, and actuation section404define substantially the entire fluid transmission pathway created by the cardiac shunt402. As such, changing the geometry of actuation section404corresponds with an alteration of the fluid transmission that occurs through conduit between the heart regions that is created by the shunt402. Within examples of system401, the implanted cardiac shunt402can optionally include additional components and features. The shunt402can integrate various electronic components410, which may include one or more sensors, microcontrollers, ASICs, FPGAs, and/or other components known to those skilled in the art. The implanted cardiac shunt402can integrate one or more energy receiving components413that are capable of receiving a signal from a source external to the cardiac shunt402. The receiving components413can include induction coils, piezoelectric receivers, antennas, other energy receiving coil(s), and/or other components known to those skilled in the art. In implementations, the one or more energy receiving components413are adapted to further relay received energy to other components (e.g., electronic components410) and thus can be used as a means to provide the implanted cardiac shunt402with electrical power. This power can be utilized to enable and/or augment the operation of sensors, microcontrollers, and/or other device components. The implanted cardiac shunt402may optionally integrate one or more energy storage components414(e.g., a battery, a supercapacitor, a capacitor, etc.). The energy storage components414may provide electrical energy to enable operation of sensors, microcontrollers, and/or other device components. Some implementations of the cardiac shunt402may contain both energy receiving components413and energy storage components414. In some such implementations, the energy receiving components413and energy storage components414can work in tandem to provide electrical power to electrical components410. In some implementations, energy receiving components413can be utilized to capture energy which is transferred to and subsequently stored in energy storage components414. Within examples of system401, the implanted cardiac shunt402includes a size measurement component or system411. The size measurement component or system411can take a spectrum of forms (e.g., sensors, visual markers, electrical circuitry, etc.) appropriate to the structure of actuation section404, and is utilized to provide quantitative and/or qualitative (e.g, actuation section404is in a relatively larger state than previously, actuation section404is in a relatively smaller state than previously, etc.) information to a user (e.g., a patient, a physician, a care provider) regarding the geometric configuration of the actuation section404at a moment in time. Implementations of an implanted cardiac shunt402may also include a docking or interface feature412(which can be substantially identical to the docking or interface feature107described above as part of system101) that may be utilized to facilitate the coupling of energy delivery catheter403with the implanted cardiac shunt402. Within examples the shunt402may optionally contain other components415not explicitly described herein (e.g., radiographic markers, material components, bioabsorbable components or layers, etc.). Referring toFIG.4, the system401includes an energy delivery catheter403or other elongated body that is adapted to interface with the cardiac shunt402at a time following its implantation into the body of a subject. The energy delivery catheter403includes an implant interface system416, which in examples is a subsystem of the catheter adapted to mechanically and/or energetically couple with the cardiac shunt402. In examples the implant interface system416is located at or near the distal end of catheter403. In examples, the implant interface system416interfaces directly with the actuation section404of the implanted shunt402. In some implementations, the implant interface system416contains a docking or interface feature421which facilitates coupling of the energy delivery catheter403to the implanted cardiac shunt402. In some embodiments, this docking or interface feature421can be substantially identical to the interface feature113described above in accordance with system101. In implementations of system401, the docking or interface feature421mates with, interfaces with, or works in conjunction with a docking or interface feature412on the implanted cardiac shunt402. In alternate implementations, the docking or interface feature421independently facilitates coupling of the energy delivery catheter403to the implanted cardiac shunt402, irrespective to the functionality of or presence of a docking or interface feature412located on the cardiac shunt402. In some implementations of system401, no docking or interface feature421is present on the energy delivery catheter403. The implant interface system416of energy delivery catheter403also includes a distal complex417located at or near the distal end of the energy delivery catheter. The distal complex417can contain components adapted to interface with the actuation section404and alter at least one geographic dimension of the actuation section404bi-directionally (i.e., the distal complex can be utilized to both enlarge or reduce a dimension of the actuation section). In the example shown, the distal complex417includes an actuator expansion component420that is used to enlarge or expand one or more components (e.g., the shape memory component405) that comprise the actuation section404. Within examples, the actuator expansion component420can alter a geometry of an actuation section404without using energy from an energy source418(described below). In examples, the actuator expansion component420is a balloon (e.g., a compliant balloon, a semi-compliant balloon, a non-compliant balloon, etc.) adapted to dilate a shape memory component405via a balloon expansion. In such examples, the actuator expansion component420may be comprised of a balloon constructed from polyurethane, silicone, polyether block amide (sold under the trademark PEBAX), latex, polyester, nylon, or other materials known to those skilled in the art and mounted to a central shaft with an inflation port. The expansion component420may be transitionable from a first (e.g., collapsed) configuration to a second (e.g., expanded) configuration by a user, for example by using a syringe coupled to a proximal complex422(described below) that resides at or near the proximal end of the energy delivery catheter403to inject an expansion medium (e.g., a fluid, gas, foam, etc.) into the balloon via a lumen in the catheter shaft (not shown inFIG.4). When positioned such that it is mechanically coupled to the shape memory component405and/or actuation section404(e.g., via docking or interface feature412and/or421), transitioning the actuator expansion component420from the first configuration to the second configuration can apply a mechanical force to shape memory component405which causes this component to enlarge, expand, or otherwise transform geometry in a way that increases a geometric dimension of actuation section404. In implementations, the shape memory component405may be in a first material state (e.g., a martensitic state, an R-phase state) at body temperature. In such implementations, the shape memory component405may be relatively malleable and thermo-elastic in this first material state, and thus be deformable/expandable by the mechanical forces applied by actuator expansion component420. In implementations, the actuator expansion component420is not significantly above body temperature (e.g., at or within 5 degrees Celsius of body temperature) when it applies mechanical forces to shape memory component405. In implementations, the actuator expansion component420is below body temperature but above a temperature that may be harmful to tissue (e.g., between 0 degrees Celsius and body temperature), such that it can reduce the temperature of the shape memory component405, thereby making shape memory component405further malleable relative to its material characteristics when at or near body temperature. Alternative implementations of a medical system with a number of features similar to and/or substantially identical to systems101and401may utilize an actuator expansion component420that does not take the form of a balloon and/or that is not part of a distal complex417. In examples, the actuator expansion component420is a metallic (e.g., stainless steel, titanium, etc.) cage that can expand (e.g., a radial expansion) from a slimmer delivery configuration to a larger implant interface configuration in respond to a user operating a control feature proximate to proximal complex422(described below). In examples, the actuator expansion component420can include one or more shape memory components that enable a geometry change (e.g., an expansion from a first, slimmer delivery configuration to a second, larger implant interface configuration) in response to the application of energy (e.g., heat) that results in the energy delivery catheter's shape memory component changing from a first material state (e.g., a martensitic state or an R-phase state) to a second material state (e.g., to an R-phase state or an austenitic state). In examples, the actuator expansion component420is adapted such that it may also be configured by a user into one or more intermediate configurations between a first and second configuration, for example by inducing an intermediate degree of balloon expansion by injecting an intermediate volume of an expansion media into a balloon. In such examples, the distal complex417is capable of imparting a plurality of geometric alterations to the actuation section404based upon the relative degree of configuration change of the actuator expansion component420. The distal complex417of the energy delivery catheter403can also contain an energy source418and an energy coupling mechanism419(which can collectively or individually be referred to as an energy delivery device and/or energy delivery element). The energy coupling mechanism419may aid in the conveyance of energy from the energy source418to the actuation section404of the implanted cardiac shunt402. The energy source418provides energy to system401that may be used to alter the geometry of actuation section404(e.g., to reduce the size of a dimension of the actuation section). Within examples, the energy source418provides energy that is coupled by the energy coupling mechanism419to the shape memory component405of actuation section404, which can result in the shape memory component405changing geometry. Within examples, when the shape memory component405undergoes a geometry change in response to the application of energy from the distal complex417, that geometry change primarily results in a decrease in a dimension (e.g., a narrowing of a diameter). In some implementations, the shape memory component405is comprised of nitinol or a nitinol-based alloy that is in a first material state (e.g., a martensitic state or an R-phase state) at body temperature, and the application of energy from the distal complex417raises the temperature of the shape memory component405above a material transition temperature such that it transitions to a second material state (e.g., an R-phase state or an austenitic state), thereby enabling a change of geometry of the shape memory component via a shape memory effect. More specifically, when the shape memory component405is in a first material state at body temperature, it can be relatively malleable or thermo-elastic and therefore be deformed away from a preferred geometry (e.g., a manufactured geometry, an original geometry, a heat set geometry, etc.). This deformation can result from a number of operations (e.g., manipulation of the shape memory component before or during implantation, expansion or other adjustment of the shape memory component using actuator expansion component420or another tool/method, etc.). As the shape memory component405is heated above a transition temperature and moves from a first material state to a second material state, it can actuate from a first (e.g., deformed) geometric configuration towards a second (e.g., a preferred) geometric configuration, thereby changing a size and/or shape of actuation section404. In some implementations of system401, there may be more than one energy source component418. In examples of such implementations, the plurality of energy source components may be similar or identical (e.g., multiple instances of a specific component or system). In further examples of such implementations, at least one energy source418varies from at least one other energy source used as part of the implant interface system416(e.g., a radiofrequency energy source used in concert with an ultrasonic energy source). Within examples of system401, the actuation section404of the cardiac shunt402is only adjusted using mechanical forces and/or energy provided by the distal complex417and/or the energy delivery catheter403. In such examples, other sources of mechanical or electrical energy associated with the system401(e.g., energy receiving components413, energy storage components414) are used exclusively in association with portions of the system not related to the actuation section404(e.g., electrical components410, size measurement component411, etc.). In alternate examples, the actuation section404of the cardiac shunt402is adjusted using a combination of mechanical forces and/or energy provided by the distal complex417and/or the energy delivery catheter403and other sources of force/energy associated with the system401. In implementations, the energy source418and energy coupling mechanism419may be a single entity (i.e., a single aspect or component of the system serves both functions). Within examples, the energy source418can provide mechanical energy, electrical energy, thermal (e.g., hot or cold) energy, electromagnetic energy, acoustic energy, or other relevant forms of energy known to those skilled in the art. Within examples of a distal complex417, energy source418is comprised of one or more radiofrequency (RF) electrodes that receive RF energy from a generator located elsewhere in system401(e.g., via a power source424located in proximal complex422or external to the energy delivery catheter403). In some implementations, RF electrodes may provide energy to actuation section404indirectly by heating an energy coupling mechanism419that serves as an intermediary medium that transfers the heat to the actuation section404. For example, a distal complex417can include a balloon that may be filled with a fluid (e.g., saline) or other conductive media such that it expands to contact at least a portion of actuation section404. The distal complex417may include internal RF electrodes that heat the filling media, which serves as an energy coupling mechanism419to transfer the heat to the actuation section404. In alternate implementations, RF electrodes may provide energy to actuation section404directly. For example, a distal complex417may include an expandable section (e.g., a balloon, a metallic cage, etc.) that is adapted such that when it is in an expanded state it contacts at least a portion of actuation section404. The expandable section may include RF electrodes at or near the exterior of the section, such that actuation section404is heated directly. In such an implementation, the energy source418and energy coupling mechanism419may take the form of the same component. Within alternate examples of distal complex417, energy source418may be an energized media that is directed by energy delivery catheter403to the distal complex417. For example, energy source418may be a pre-heated or pre-cooled liquid, gas, or foam that is energized remote from the distal complex417(e.g., via a power source424located in proximal complex422or external to the energy delivery catheter403) and directed to the distal complex417through lumens, ports, or other aspects of energy delivery catheter403. In some implementations, an energized media could be further energized (e.g., reheated or additionally heated) by one or more supplemental energy sources418located along aspects of the catheter (e.g., in the distal complex417, along the catheter shaft, etc.). It will be clear to a skilled artisan that additional implementations of energy source418and energy coupling mechanism419are possible without loss of novelty. Referring toFIG.4, the energy delivery catheter403that is part of system401can further include a proximal complex422that can include a catheter handle or handpiece intended to be held by a user during operation. The proximal complex422may include various user control features that enable the operator to perform actions related to catheter operation (e.g., steering operations, energy delivery operations, fluid/contrast injection operations, etc.). Control features can include various dials, triggers, buttons, knobs, pulleys, switches, and other control features known to those skilled in the art. The handle can be comprised of plastic or other polymer or metallic materials, or combinations of these materials. Some examples of an energy delivery catheter403that is part of system401can further include additional features. Some implementations may feature one or more injection ports423, for example a port that can interface with a syringe (not shown) to inject media into the catheter (e.g., an energy source media, a saline flush, a balloon inflation media, a contrast agent, etc.). Some implementations may contain one or more power sources424. A power source424can be used to provide energy to various aspects of catheter403(e.g., aspects related to energy source418, aspects related to steering or navigation of the catheter, aspects related to lighting or illumination features, aspects related sensing and diagnostics, aspects related to functionality of electronics in the handle, etc.). The power source424can be a battery, a capacitor, a generator integral with or operably coupled to the catheter, an ultrasonic transducer, or other sources of power known to those skilled in the art. Some implementations of an energy delivery catheter403may contain steering components to aid in navigation of the catheter in and around target anatomy. Steering components may be comprised of pull wires, robotic components (e.g., those powered via power source424), or other assemblies known to those skilled in the art. Some implementations of the catheter403may contain other various components426, which could include the catheter body and/or shaft, one or more lumens, guidewires and/or sheaths, contrast or fluid ejection ports, illumination features, radiographic markers, sensors and diagnostics, and/or other components. Moreover, although described as a catheter403, the catheter403can alternatively or additionally comprise a sheath, guidewire, dilator, or other elongated body configured to extend through the patient's vasculature and interface with the shunt402(the foregoing can be collectively referred to as an “elongated body” or an “energy delivery apparatus”). FIGS.5A-6Bshow a plurality of implementations that can be instituted in connection with the medical systems101and401shown inFIGS.1and4, respectfully, according to examples of the present disclosure.FIGS.5A-5D, for example, illustrate an implantable interatrial cardiac shunt503configured in accordance with an embodiment of the present technology.FIGS.5A and5Cshow the shunt from a first partially isometric view as the shunt would be seen from inside the RA of a patient, whileFIGS.5B and5Dshow a second partially isometric view featuring the opposite side of the shunt, as it would be seen from inside the LA of a patient. InFIGS.5A and5B, the shunt is shown in a first, relatively more open configuration, with an actuation section in a larger or expanded state. InFIGS.5C and5D, the shunt is shown in a second, relatively more closed configuration, with an actuation section in a smaller or contracted state. In the illustrated embodiment, the cardiac shunt503includes an actuation section504having a shape memory component505and a membrane506, a shunt frame507, and a frame membrane508, among other features. As shown, cardiac shunt503has a body defined by frame507. Frame507can have a metallic structure and be self-expanding (e.g., if comprised of nitinol manufactured to exhibit superelastic properties at body temperature) or balloon expandable (e.g, if comprised of stainless steel, if comprised of nitinol manufactured to be largely martensitic at body temperature, etc.). As shown, frame507is mechanically-connected to a plurality of RA side anchoring elements509aand a plurality of LA side anchoring elements509b. In various examples, any number of anchoring elements may be utilized, and anchoring elements may take on various forms as described above. In implementations, the frame507and anchors509are a unibody that has been manufactured to self-deploy into the desired configuration during implantation (e.g., when released from a sheath or catheter, as known to those skilled in the art). In variation implementations, the frame507may be joined to anchoring elements509during manufacturing (e.g., using adhesives, welds, rivets, sutures, and the like). In some implementations, frame507may be joined to anchoring elements509via the membrane508(described below). Within examples, the frame507may join to a first set of anchoring elements (e.g., to elements509a) using a first joining method and may join to a second set of anchoring elements (e.g., to elements509b) using a second, different joining method. In the example shown, anchoring elements509aand509bare intended to interface with a septal wall (not shown) to stabilize the position of the cardiac shunt503. In examples, LA-side anchoring elements509bmay be relatively smaller and flat in order to reduce thrombogenicity in the left heart. In examples, RA-side anchoring elements may be relatively larger and have a shape and a flexibility to accommodate septal wall thickness variations that can be encountered in different portions of the septum and among different patients. In some implementations, coil-like anchoring elements may be implemented in order to address anatomical variations while also maintaining a relatively flatter profile, which may accelerate tissue overgrowth of the elements and further reduce risk of thrombus. Cardiac shunt503can also contain a frame membrane508that can be operably-coupled to frame507and to LA-side anchoring elements509b. In variation implementations, membrane508may alternatively or additionally be coupled to RA-side anchoring elements509a. As shown, frame membrane508is affixed to an exterior surface of frame507and anchoring elements509b. The fixation can be accomplished using various techniques known in the art (e.g., using adhesives, electrospinning of the membrane material, melting of the material onto the frame, suturing, interlocking components, etc.). Membrane508can be affixed to the frame507in any number of arrangements. For example, in variation implementations, membrane508can be affixed to an interior surface of the frame507and/or anchoring elements509. In further variations, the frame507and/or anchoring elements may be sandwiched between multiple layers of membrane508. In such variations that utilize multiple membrane layers, the material comprising the membrane on a first side of the frame507(e.g., an internal side) may differ from the material comprising the membrane on a second side of the frame507(e.g., an external side). This may be done to optimize performance of the implant—for example on the internal surface of the frame a membrane material can be selected to optimize for blood flow considerations, while on the external surface of the frame a membrane material can be selected to optimize for tissue response (e.g., to reduce any inflammatory response of septal tissues). Cardiac shunt503further contains the actuation section504defined as the complex of the actuation section membrane506and the shape memory component505. The actuation section504in this example is located on the RA side of the shunt, but in variation implementations can be located elsewhere on the implanted shunt device503. The actuation section504can have a conical or tapered shape and include an opening or aperture550that defines the exit path for fluid traveling from the LA to the RA through the shunt. Together with the frame507and frame membrane508, the actuation section504defines a lumen or fluid passageway that blood can travel therethrough. While the size and shape of the portion of the lumen defined by the frame507and frame membrane508remains constant or substantially constant through all operational states following implantation of the cardiac shunt503, as described below the portion of the lumen defined by the actuation section504may vary in response to user/provider actions. As such the flow rate through cardiac shunt503can be altered by adjusting the actuation section504into different configurations. In some implementations, portions of the shunt frame507can provide additional structural support to aspects of the actuation section504. For instance, within examples elongated extensions of frame507can interface with actuation section membrane506to provide shape and structural integrity to this section. In said examples, these extensions of the frame507may be flexible in nature in order to accommodate changes in geometry of the actuation section504. In variation implementations, the actuation section504may alternatively or additionally have other structural support (not shown), for example a lattice structure embedded into or otherwise coupled to the actuation section membrane506. Within examples, the actuation section membrane506can be identical to, similar to, or contiguous with frame membrane508. In alternate examples, the actuation section membrane506may be constructed of a different material than frame membrane508. In general, actuation section membrane506should be relatively fluid impermeable, relatively non-thrombogenic, and have some degree of flexibility to facilitate geometry changes associated with this section of the shunt. In examples, it may be constructed of silicone, ePTFE, nylon, a polyurethane, another polymer, or another appropriate material. In implementations, frame membrane508and actuation section membrane506are joined, fixed, or otherwise interfaced such that a continuous, relatively leak-free fluid pathway is created along the lumen defined by the cardiac shunt503. The actuation section membrane506is integral with shape memory component505, and can be affixed to the exterior surface of component505, affixed to the interior surface of component505, be comprised of multiple layers that surround component505, or be coupled in some combination of these ways or in a different way. Accordingly, as the shape memory component505changes in geometry, it can induce a change in geometry of the membrane. This geometry change may take the form of a stretching/relaxation of the membrane, a change in position (e.g., a change in angle of the membrane relative to shunt frame507), some combination of these forms, or another form. As shown inFIGS.5A-5D, the shape memory component505is configured as a ring with a zig-zag pattern. Such a pattern allows for radial expansion (i.e., a widening or opening of aperture550, for example producing the configuration ofFIGS.5A-5B) and radial compression (i.e., a narrowing or closing of aperture550, for example producing the configuration ofFIGS.5C-5D) of the shape memory component505to occur by inducing thermo-elastically recoverable deformations. This is an important feature which allows for repeated bi-directional adjustment of the actuation section (and therefore the shunt lumen, which governs flow through the shunt), as described in detail below. FIGS.6A and6Billustrate a distal section of an energy delivery catheter603configured in accordance with embodiments of the present technology. In particular,FIG.6Ashows a view of the catheter with a distal complex617in a first, slim-profile configuration.FIG.6Bshows a view of the catheter with a distal complex617in a second, relatively expanded configuration.FIGS.6A and6Bshow example implementations of a distal complex617that features an energy source618, an energy coupling mechanism419(FIG.4), and an actuator expansion component620, among other features. For clarity, the proximal portions of catheter603(which can include a proximal complex, power source, and other features) are not shown in the figures. However, as described below, these components are present within examples of the present technology. Energy delivery catheter603includes a catheter body or shaft655that connects its proximal portions and distal portions (e.g., distal complex617). The catheter body655is an elongated and flexible structure and may be comprised of various materials (e.g., silicone, polyurethane, polyethylene, polyvinylchloride, PTFE, nylon, etc.) known to those skilled in the art. The catheter body655can contain a plurality of lumens, for example lumens to accommodate the use of a guidewire (not shown), lumens to allow a media (e.g., an expansion media) to move between proximal and distal aspects of the catheter, and/or other lumens. The distal complex617can be adapted to interface with the actuation section of an implanted medical device (e.g., cardiac shunt503). The distal complex617can include an expandable balloon620that may be expanded from a first slimmer configuration (e.g., as shown inFIG.6A) to a second larger configuration (e.g., as shown inFIG.6B) by filling the balloon with an expansion medium (e.g., a fluid, gas, foam, etc.). Removing all or some of the expansion media from the balloon620can reverse the expansion and/or reduce the size of the balloon. Within examples, a dimension of the balloon620can also be reduced in size without removing media from its interior (e.g., if a compressive force is applied to the balloon that induces a shape change in the balloon via a transverse strain or expansion related to the Poisson effect). Expansion media can be transmitted into or out of the balloon by an operator, for example by utilizing a syringe coupled to an input port on a catheter handle that is part of the proximal complex (not shown). In such an implementation, media injected into the catheter603via a syringe would travel though a lumen (not shown) in catheter body655and exit an outflow port656located inside the portion of distal complex617encompassed by the balloon620. In implementations, the balloon expansion media is an electrically and/or thermally conductive media (e.g., saline). In implementations, the balloon expansion media may serve as an energy coupling mechanism (e.g., coupling mechanism419) as described above. As described above, the distal complex617of energy delivery catheter603can include an energy source618, which in some embodiments can include at least one electrode618(e.g., an RF electrode) that is affixed to the catheter body in the region surrounded by balloon620. The electrode618is electrically-coupled to a power source (not shown) that is located remote from the distal complex617(e.g., in a catheter handle, in a generator separate from the catheter603, etc.), for example via electrical wires that travel through a lumen (not shown) in, or embedded within, the catheter body655. When energized (e.g., via a user toggling a control feature on a catheter handle to enable a power source), the electrode618can transfer energy to surrounding media (e.g., saline that fills a balloon) and cause the surrounding media to elevate in temperature. These elevations in temperature may be subsequently transferred/coupled to structures located proximate to the heated media (e.g., to the actuation section of cardiac shunt503). Within examples, the energy delivery catheter603can be constructed with the electrode618residing elsewhere in the system so long as the expansion media (e.g., saline) can be heated by the electrode. For example, electrode618may reside along the length of the catheter body655or within the proximal complex422(FIG.4). Within examples, an expandable balloon620on catheter603can include one or more perforations that allow an expansion media to be expelled into the environment. In such implementations, the number, size, and/or locations of the perforations can be configured such that expansion media is generally only expelled from the balloon once a pressure threshold has been reached (e.g., after filling sufficiently to shift the balloon to a larger configuration (i.e., as shown inFIG.6B)). In implementations, the expansion media that is expelled can be energized as described above and therefore can serve as an energy source418(FIG.4) and/or energy coupling mechanism419(FIG.4). In such examples, the energized media may be expelled into regions surrounding balloon620(e.g., into regions surrounding an actuation section of cardiac shunt503), which can facilitate the elevation of local temperatures. This may allow for more rapid energy transfer to an actuatable component, and may further facilitate actuation of a contracting component by removing at least some counterforce that would be applied by a non-perforated balloon in contact with an actuation element. FIGS.7-9show a plurality of flowcharts of methods of use that can be instituted in connection with examples of the present disclosure. More particularly,FIGS.7-9provide flowcharts of methods of use that are substantially similar to method200and/or method300described above, and that can be instituted in connected with examples such as those shown inFIGS.5A-6B. A flowchart describing a method of use (“method700”) for adjusting a medical system that can be utilized in conjunction with the presently described technologies is shown inFIG.7. Beginning at step701, the method700can involve inserting an energy delivery balloon catheter (e.g., catheter603) into the vasculature of a patient and navigating the catheter to the patient's heart with the balloon (e.g., balloon620) in a first, slimmer profile configuration (e.g., as shown inFIG.6A). A second step702can involve positioning the energy delivery balloon catheter within the lumen of an actuatable portion of a cardiac shunt (e.g., cardiac shunt503) while the actuatable portion is in a first state associated with a first geometry. A third step703can involve inflating the balloon with an expansion medium such that the balloon expands into a second, larger configuration (e.g., as shown inFIG.6B) and applies a radial force to a relatively malleable component (e.g., component505) within the actuatable portion of the cardiac shunt, thereby enlarging a geometry of a section of the shunt in a manner that is reversible, and increasing the flow potential therethrough. A fourth step704can involve deflating the balloon by removing expansion media and therefore reducing the size of the balloon relative to the second, larger configuration, and removing the catheter from the body in a manner that maintains the actuatable portion of the shunt in an increased-sized geometry relative to the first shunt state and shunt geometry. Method700may be useful if it is desired to temporarily enlarge a shunt lumen diameter while retaining the ability to reverse said enlargements. For example, a physician may want to enlarge the diameter of an interatrial shunt to further relieve LA pressure, but may be uncertain if the patient's right-heart function is sufficiently strong to handle the increased blood volume and load. Method700enables a physician to evaluate the patient's response to the new shunt configuration for a period of time (e.g., minutes, hours, days, weeks, months, etc.) without jeopardizing the ability to return the patient safely to the original configuration if the patient response is unsatisfactory for any number of reasons. A flowchart describing a method of use (“method800”) for adjusting a medical system that can be utilized in conjunction with the presently described technologies is shown inFIG.8. A step801can involve inserting an energy delivery balloon catheter (e.g., catheter603) into the vasculature of a patient and navigating the catheter to the patient's heart with the balloon (e.g., balloon620) in a first, slimmer profile configuration (e.g., as shown inFIG.6A). A second step802can involve positioning the energy delivery balloon catheter within the lumen of an actuatable portion of a cardiac shunt (e.g., cardiac shunt503) while the actuatable portion is in a first state associated with a first geometry. A third step803can involve inflating the balloon with an expansion medium such that the balloon expands into a second, larger configuration (e.g., as shown inFIG.6B) and establishes contact with a shape memory component (e.g., component505) within the actuatable portion of the cardiac shunt. A fourth step804can involve applying heat to the shape memory component within the actuatable portion of the shunt via an energy source (e.g., RF electrode618) within or operably-coupled to the balloon, thereby raising the temperature of one or more sections of the shape memory component above a material state transition temperature and causing the shape memory component to move towards a preferred geometry and consequently changing the geometry of the actuatable portion of the shunt to a second geometry different than the first geometry. Within implementations, steps803and804can be iteratively performed multiple times (e.g., iteratively) to arrive at the desired shape of the actuator. A fifth step805can involve deflating the balloon by removing expansion media and therefore reducing the size of the balloon relative to the second, larger configuration, and removing the catheter from the body in a manner that maintains the actuatable portion of the shunt in an altered geometry relative to the first shunt state and shunt geometry. Within examples, method800can be utilized to reduce a geometry of at least a portion of a shunt from a relatively larger size (e.g., diameter) to a relatively smaller size. In such examples, the shape memory component in the actuation section of the shunt has been deformed from a preferred geometry, and is configured in a geometry that is larger or expanded relative to the preferred geometry. Accordingly, as the shape memory component is heated in step804, the shape memory component will contract as it moves towards its preferred geometry. Method800is useful because it provides care providers with a practical and reversible technique for making a shunt lumen smaller after the time of shunt implantation, a capability not available in present devices and not described in the prior art. Method800is also useful because such contractions in a lumen geometry are reversible (i.e., the shape memory component can be later expanded into a larger geometry, for example via method700). A shunt lumen/fluid conduit that can be reduced in size at a time following implantation and can later be enlarged represents a substantial leap forward in medical care and unlocks new treatment paradigms that physicians may offer to their patients. A flowchart describing a method of use (“method900”) for adjusting a medical system that can be utilized in conjunction with the presently described technologies is shown inFIG.9. A step901can involve inserting an energy delivery balloon catheter (e.g., catheter603) into the vasculature of a patient and navigating the catheter to the patient's heart with the balloon (e.g., balloon620) in a first, slimmer profile configuration (e.g., as shown inFIG.6A). A second step902can involve positioning the energy delivery balloon catheter within the lumen of an actuatable portion of a cardiac shunt (e.g., cardiac shunt503) while the actuatable portion is in a first state associated with a first geometry. A third step903can involve inflating the balloon with an expansion medium such that the balloon expands into a second, larger configuration (e.g., as shown inFIG.6B) and establishes contact with a shape memory component (e.g., component505) within the actuatable portion of the cardiac shunt. A fourth step904can involve applying heat to the shape memory component within the actuatable portion of the shunt via an energy source (e.g., RF electrode618) within or operably-coupled to the balloon, thereby raising the temperature of one or more sections of the shape memory component above a material state transition temperature and causing the shape memory component to move towards a preferred geometry and consequently reducing the geometry of the actuatable portion of the shunt to a second geometry smaller than the first geometry. A fifth step905can involve: with the energy source deactivated, inflating the balloon with an expansion medium that is near or below body temperature such that the balloon expands into a configuration larger than the first, slimmer profile configuration and applies a radial force to the shape memory component within the actuatable portion of the cardiac shunt without raising the temperature of the shape memory component above a material state transition temperature, thereby deforming the relatively malleable shape memory component and enlarging a geometry of a section of a shunt to a geometry larger than the second shunt geometry, and consequently increasing the flow potential therethrough. A sixth step906can involve deflating the balloon by removing expansion media and therefore reducing the size of the balloon relative to the second, larger configuration, and removing the catheter from the body in a manner that maintains the actuatable portion of the shunt in an altered geometry relative to the second shunt geometry. In variations of method900, steps903and904may be combined into a single step. For example, in an implementation of method900when an expansion media (e.g., saline) is heated remote from the distal complex (e.g., heated in the handle) and then delivered to the distal complex, the balloon can inflate to contact a shape memory component while simultaneously transferring heat from the energized expansion media to the shape memory component. In other variations of method900, step905can be an optional step. Further variations of method900can contain an additional step that involves removing expansion media from the balloon between heating the shape memory element to cause a reduction in size via the shape memory effect and re-expanding the shape memory element to a larger size using a radial force (e.g., between steps904and905). Including this optional additional step may offer at least two advantages: (a) it can ensure that any heated (i.e., heated relative to body temperature) media in the balloon is removed prior to the expansion step905, thereby reducing the likelihood of unintentionally re-heating the shape memory element above a transition temperature; (b) it can increase the precision with which the expansion step905can enlarge a shape memory element to a known size, given that the volume of expansion media in the balloon during step905may be more precisely known using this methodology. Method900is useful because it can leverage a medical system capable of reversible bi-directional adjustment in order to increase the accuracy and/or precision with which the system can be adjusted. For example, during step904, the actuation section of the shunt will be predictably and reliably moved into a known geometry. This provides a stable and repeatable baseline geometry/size from which any balloon expansion can start from. Given this baseline geometry, the degree of expansion in step905can be proportional to other factors in the physician's control (e.g, the volume of expansion media used to expand the balloon during this step). More accurate and precise adjustments of a shunt will allow for improved management of LA and RA pressures, and may lead to improved patient outcomes when treating HF. Although the methods700-900are described primarily with respect to adjusting a shunt using a balloon, the present technology can also utilize expandable members other than inflatable balloons to adjust the actuation sections of the shunts described herein. For example,FIGS.10A and10Bshow a distal section of an energy delivery catheter1003having a distal complex1017including an expandable cage or frame1060and configured in accordance with embodiments of the present technology. More specifically,FIG.10Ashows a side view of the catheter with the distal complex1017in a first, slim-profile configuration, andFIG.10Bshows a side view of the catheter with the distal complex1017in a second, relatively expanded configuration.FIGS.10A and10Bshows example implementations the distal complex1017that feature an energy source1018, which can in some embodiments serve as a combined energy coupling mechanism and actuator expansion component, and other features. For clarity, the proximal portions of catheter1003(which can include a handle that is part of a proximal complex (e.g., the proximal complex422shown inFIG.4), power source (e.g., the power source424shown inFIG.4), and other features) are not shown in the figure. However, these components are present within examples of the present technology. Energy delivery catheter1003includes a catheter body or shaft1055that connects its proximal portions (e.g., proximal complex) and distal portions (e.g., distal complex1017). The catheter body1055can be substantially similar to the catheter body655described above with respect toFIGS.6A and6B. The distal complex1017can be adapted to interface with the actuation section of an implanted medical device (e.g., cardiac shunt503). As described above, the distal complex1017can include a metallic cage1060that may be expanded from a first slimmer configuration (e.g., as shown inFIG.10A) to a second larger configuration (e.g., as shown inFIG.10B) by a user, for example by toggling a control feature on a catheter handpiece (not shown) that shortens the length of the cage in a manner that causes it to expand radially. As such, the metallic cage1060can apply a radial force to an actuation section of an implanted device and thereby serve as an actuator expansion component (e.g., similar to components420and620). Energy delivery catheter1003can also contain a plurality of electrodes1018that can delivery energy (e.g., RF energy) to a component and thereby serve as an energy source (e.g., similar to components418and618). In the implementation shown, energy is produced by a generator located remotely from distal complex1017(e.g., in a catheter handle, outside of the catheter, etc.) and transmitted down catheter body1055to electrodes1018. Within examples, electrodes1018can directly heat a component in an actuation section of an implanted device. In such examples, the electrodes1018would also serve as the energy coupling mechanism (e.g., similar to component419) in the system. Within alternate examples, electrodes1018can be used to heat the metallic cage1060or portions thereof, and the metallic cage can transfer heat to a component in an actuation section of an implanted device. In such examples, the metallic cage would also serve as the energy coupling mechanism (e.g., similar to component419) in the system. In some implementations, some combination of components are used to transfer heat or other forms of energy from the catheter1003to a component in an actuation section of an implanted device. As described above, implementations of the presently disclosed technology involve an expandable compartment (e.g., a balloon) in the distal complex of an energy delivery catheter receiving an energized or energizable medium (e.g., saline). Within examples (e.g., catheter603) the media can be energized once it has been transferred to the distal complex. This technique may be advantageous to avoid energy loss as the media is transferred through a catheter body to the distal complex. In alternate examples, the media may be energized prior to being transferred to the distal complex (e.g., a medium is pre-heated and injected into the catheter using a syringe that interfaces with a catheter lumen, a medium is injected into the catheter and pre-heated in a compartment that is integral to the catheter but remote from the distal complex prior to being transferred to the distal complex, etc.). Although this technique may result in the media experiencing energy loss prior to it reaching the distal complex, it may lead to more rapid transmission of energy to the actuation complex since the media will arrive at the distal complex energized and not need to undergo an energizing process, which may take time. This could result in faster procedure times, which can benefit physicians, patients and the healthcare system. Some examples of the presently disclosed technologies can utilize multiple energy sources and take a hybrid approach, where media is at least partially energized prior to transfer to the distal complex and then subsequently energized again after transfer to the distal complex. In some instances, this approach could balance the benefit of reducing energy loss experienced by the media as it travels to the distal complex with the benefit of reduced heating time of the media once it is present in the distal complex. Some implementations of the present technology will include docking or interface features on the implanted device and/or the energy delivery catheter. These features may assist with several aspects of system functionality. In examples, the docking feature(s) facilitate positional stability between a catheter and an implanted device as one or more actions (e.g., an actuation section adjustment) are being performed. This may have particular benefits for devices positioned in certain anatomic locations, for example for cardiac devices where the beating heart can induce unwanted absolute or relative movement of the devices. The docking or interface feature(s) may also facilitate proper alignment of aspects of the system, for example the alignment of an energy source on an energy delivery catheter with a shape memory component in an actuation section of an implanted device. Features that facilitate proper alignment may improve the efficiency of the system, for example by ensuring that any energy/heat generated by the system is delivered exclusively or primarily to the desired regions of the implanted device. FIGS.11A-11C, for example, illustrate a distal complex1117of an energy delivery catheter1103having a docking feature1170and configured in accordance with embodiments of the present technology.FIG.11Ashows a side view of the catheter1103with the docking feature1170in a first configuration.FIG.11Bshows a side view of the catheter1103with the docking feature1170in a second configuration.FIG.11Cshows a side view of the catheter1103as it interfaces with an implanted medical device. The energy delivery catheter1103includes a catheter body1155and a distal complex1117. The distal complex1117can include an expandable section (e.g., a balloon)1120and an energy source (e.g., an electrode)1118that can be substantially similar to expandable sections420and620and energy sources418and618described above. The distal complex1117can also include one or more docking features1170located near the distal tip of the catheter. In some implementations, docking features1170are established in a fixed position (e.g, a fixed distance away) relative to another feature of the catheter (e.g., the energy source, the actuator expansion component, etc.). Docking features1170may be initially in a first, narrow configuration (e.g., as inFIG.11A) where they are aligned closely to catheter body1155, giving the catheter a slim profile that can increase maneuverability through small or complex anatomy. When desired, the user can operate a control feature (e.g., a dial that controls one or more pull wires) on a catheter handle (not shown) that deploys the docking features1170into a second, expanded configuration (e.g., as inFIG.11B). As described below, adapting the catheter1103into this expanded configuration can increase the stability and positional accuracy of the catheter as it interfaces with an implantable device and facilitate use of the system during a reversible adjustment of the device's geometry. Referring toFIG.11C, a system1100including the energy delivery catheter1103(only distal portion shown for clarity) and an implanted interatrial shunt1102is shown according to an example. Shunt1102can be substantially similar to implanted devices102,402, and503, and is shown positioned in a septal wall S of a patient. Shunt1102can be affixed to the septal wall via a frame and/or via anchors1109aand1109b. The RA side of the shunt includes an actuation section1104that contains a shape memory component that can be energized and actuated as described above. In an example method of use, a user would first pass catheter1103through the lumen of shunt1102with the docking features1170in a narrow configuration (e.g., similar to as shown inFIG.11A). With the distal tip of catheter1103in the LA, the user can direct the docking features1170into an expanded configuration (i.e., as inFIGS.11B and11C), and withdraw the catheter position until the docking features1170establish contact with the LA side of the shunt frame. Configured in this way, system1100can allow for the relative positions of catheter1103and shunt1102to be fixed, thereby aligning an energy source, energy coupling mechanism, and/or an actuator expansion component with an actuation section of a device. Within examples of the presently disclosed technologies, implanted devices and/or energy delivery catheters can include thermal insulation components. Thermal insulation components may serve multiple purposes, and in some implementations may serve several purposes simultaneously. In implementations, a thermal insulation component can ensure that energy supplied by an energy delivery catheter to an implanted device does not elevate temperatures in unwanted regions (e.g., in tissue regions, in other regions of the device, etc.). In some implementations thermal insulation components can insulate shape memory components or other actuation components that need to be heated from blood (e.g., blood in an atrium), limiting the thermal quenching effects of the blood volume and thereby allowing more efficient and effective heating of an actuation component. In some implementations, an actuation section may contain multiple shape memory components, and thermal insulation can be used to thermally insulate one component from another to prevent unwanted simultaneous actuation. Thermal insulation can be accomplished using various materials with relatively low thermal conductivity (e.g., ePTFE, silicone, Dacron, polyurethanes, etc.) known to those skilled in the art. For example, an exterior surface of an actuation section membrane (e.g., component406, shown inFIG.4) can be comprised of or integrated with a material that limits thermal transfer through the membrane. Such an approach allows for effective thermal transfer to the interior surface of the actuation section (i.e., where an energy delivery catheter would interface) while limiting thermal exposure beyond this region. Within examples of the disclosed technologies, a geometric dimension of an implanted device can be adjusted bi-directionally, but the total size or footprint of the device (e.g., as defined by the device's outer diameter) remains unchanged during any adjustment. In some implementations, for example, cardiac shunt503shown inFIG.5, the geometries of other portions of the device (e.g., the portion of a shunt lumen defined by a shunt frame507and frame membrane508) in addition to the footprint can also remain stable even when the geometry of a specific portion (e.g., of an actuation section504) is adjusted. This aspect of the presently disclosed technologies is valuable because it allows an implanted device to be adjusted without risk of accidentally dislodging the device or inadvertently removing the device from the body. In addition, this aspect is valuable because it allows a device geometry to be expanded without stretching or interfacing with soft tissues in any way. Such soft tissue interactions may lead to damage, inflammation, thrombus, pannus formation, and/or other undesirable tissue effects. As described above, the systems disclosed herein allow for device geometries to adjusted bi-directionally, and adjusted in a manner such that geometry changes are reversible. This aspect of the presently disclosed technologies represents an advancement over the prior art. For example, some existing implanted devices (e.g., stents) can be balloon expanded either during implantation or at a later time due to the malleable nature of the device materials. However, following expansion, these devices cannot be contracted back to the previous geometry. In the context of an interatrial shunt, the capability for reversible and bi-directional adjustment of a shunt lumen offers numerous advantages. For example, if a heart failure patient's condition changes, it may be desired to increase a shunt lumen to allow for a greater volume of fluid flow from the LA to the RA. However, if the patient's condition changes again at a later time, or if the patient's right-heart reacts poorly to the load presented by the additional flow, it may be desirable to undo the shunt lumen increases and revert to a smaller lumen size. Without an ability to accomplish this reversal, many physicians would be hesitant to enlarge a shunt lumen in any patient. Heart failure is a heterogenous and unpredictable disease, and giving physicians an ability to evaluate a particular shunt lumen setting to assess patient response without being permanently locked into the evaluation setting represents a leap forward in the management of these patients. In some implementations of the presently disclosed technologies, aspects of an implanted device and/or an energy delivery catheter may be designed to be MR-resonant (i.e., excitable via exposure to a magnetic field, for example a magnetic field produced by an MRI machine). In some such implementations, a non-compliant balloon on an energy delivery catheter can have a fixed size, and be placed inside of a lumen/orifice of an implanted device. An actuator element can then be heated using a magnetic field, which could heat the element above a material transition temperature (as described above) and cause the element to contract in size until it is supported by the non-compliant balloon. Such a system can enable precision size adjustments of an implanted device. As articulated above, there are many suitable implementations of the systems described herein. In some operating conditions, certain implementations may become more practical and/or more favorable for use. For example, with implanted devices in high blood flow regions (e.g, with use of an implanted cardiac device), an energy source comprised of an expelled media (e.g, hot saline or heated foam ejected from the distal complex of an energy delivery catheter) may be cooled by heat sink/quenching effects of the blood volume and also be carried by the blood flow away from the targeted energy delivery region. Accordingly, in operation, it can require additional time, media volume, and/or exposure to impart a phase change in a shape memory component integrally formed with an actuation section of the implant. This can lead to unreliable and/or unacceptable performance of the system. In such high flow operating conditions, the use of directly-applied energy sources (e.g., radiofrequency energy, energy from resistive heating, laser or other optical energy, energy from inductance heating, microwave energy, focused ultrasound energy, etc.) can heat component(s) of an actuation section of an implant more effectively than indirect heating applied via the delivery of an expelled energized media and, therefore, can be less affected by losses related to blood flow. However, use of these energy sources may in some instances be undesirable due to the need for more expensive and sophisticated delivery catheters and more comprehensive safety protocols required to protect tissue structures proximate to the targeted region from experiencing unwanted temperature elevations and/or other undesirable affects during therapy. In such operating conditions, implementations that utilize a contained, indirectly-applied (i.e., conveyed via an energy coupling mechanism) energy source may be optimal for use. Referring back toFIGS.6A and6B, for example, one example of such an implementation is energy delivery catheter603comprising an expandable balloon620that can be filled with an energized expansion media. Such a configuration is expected to be less resistant to cooling and dissipation effects attributable to blood volume and flow, while maintaining technical simplicity, improved ease-of-use, and relatively improved patient safety. Further variations of the systems, devices, and methods described herein can be useful to improve the efficiency, accuracy, safety, and/or other attributes of adjustment techniques related to implantable medical devices.FIG.12, for example, illustrates a distal end portion of an energy delivery catheter1200configured in accordance with another embodiment of the present technology. The catheter1200may be integrated into part of a medical device system (e.g., system101, system401) as described herein. In other embodiments, however, the catheter1200may be integrated into other suitable systems. The catheter1200includes a shaft or elongated body1201that connects proximal portions of the device (not shown) with the distal complex as illustrated. The catheter1200also includes a plurality of expandable balloons, including a first expandable balloon1202and a second expandable balloon1203. In one implementation, the first expandable balloon1202may serve as and/or contain an energy source and/or energy coupling mechanism for the catheter1200. The first and second expandable balloons1202and1203may be similarly shaped and/or sized, or may have different shapes and sizes. In some embodiments, for example, the second expandable balloon1203is larger in at least one dimension and/or has a larger surface area than first expandable balloon1202. In other embodiments, the second expandable balloon1203is smaller in at least one dimension and/or has a smaller surface area than first expandable balloon1202. In some embodiments, multiple balloons may be connected to a single lumen to deliver substances (e.g., expansion media) between the proximal portion of the catheter1200and the balloons. In still further embodiments, at least one balloon is connected to a lumen that is different than the lumen from at least one other balloon on the catheter1200. The first and second balloons1202and1203can be comprised of similar materials or may be comprised of different materials. In one embodiment, for example, the first balloon1202can be a non-compliant or semi-compliant balloon and the second balloon1203can be a compliant balloon. In other embodiments, however, the first and/or second balloons1202and1203may be composed of different materials and/or have different features. It will be understood by one skilled in the art that any number of balloons, with any combination of sizes and materials, with any one or more balloons serving as or and/or containing an energy source and/or energy coupling mechanism, may be utilized within embodiments of the present technology. Further, in some embodiments, one or more alternative expandable features (e.g., an expandable wire cage or mesh, etc.) can be substituted for one or more balloons1202/1203of the catheter1200. FIGS.13A-13Dare partially schematic, cross-sectional views illustrating representative steps in a method of using the catheter1200(FIG.12) to interface with and adjust an implanted medical device. Referring first toFIGS.13A and13Btogether, an implanted interatrial shunt1301has been previously implanted into a sepal wall S of a patient. The shunt1301includes at least one actuation section1302that resides in the right atrium RA of a patient and that includes a shape memory component (not explicitly shown). For clarity, some features of the shunt device unrelated to the presently described method are not shown and/or are not labeled. In a first configuration (FIGS.13A and13B), the actuation section1302is configured such that the shunt defines a lumen through which blood may flow between the atria, with the lumen having at least one portion (e.g., an end portion) characterized by a first dimension D1. In an initial step of the disclosed method, the catheter1200is positioned inside of the patient's body by a user (e.g., through venous access) and navigated to the RA while the catheter1200is in a first, low-profile delivery configuration. As illustrated inFIG.13A, the catheter1200may be passed through the lumen of the shunt1301such that a portion of the catheter body extends through the shunt1301, and portions of the catheter1200reside in both the RA and the LA. With the catheter1200positioned as described, a user may expand the second (distal) balloon1203. In some embodiments, the second balloon1203is larger than the shunt lumen and can be larger than the entire shunt structure. In one particular embodiment, after expanding the second balloon1203, a user may retract the catheter1200proximally such that the second balloon1203establishes contact with the septal wall and/or the shunt1301or structures associated with the shunt1301. In such a configuration (as best seen inFIG.13B), the second balloon1203can serve as a docking feature (e.g., to help stabilize catheter position), can serve as an alignment feature (e.g, to help align key structures on the catheter with desired corresponding structures on the shunt), as a flow obstruction feature (e.g., to temporarily prevent blood flow through the shunt lumen), and/or for other purposes. It will be further appreciated that retracting the catheter1200such that the second balloon1203presses against the shunt1301and/or the septal wall may help align the location of the catheter1200containing the first (proximal) balloon1202with an actuation section1302of an implanted shunt. Accordingly, retracting the catheter1200proximally such that second balloon1203presses against the shunt1301and/or the septal wall may assist with the dimensional alteration of a shape memory component in an actuation section of the shunt1301by occluding the lumen of the shunt1301and preventing blood flow therethrough, thereby limiting the heat-sink and/or energy-carrying effects that blood flow traveling through the shunt1301may have on energy delivered via the first balloon1202(acting as an energy source/energy coupling mechanism) to the shape memory component. FIG.13Cillustrates an additional step in the method of using catheter1200to interface with and adjust the implanted interatrial shunt1301(FIG.13A). In this step, a user expands first balloon1202while maintaining the second balloon1203in an expanded state and positioned against the LA septal wall and/or shunt. In the illustrate embodiment, the first balloon1202aligns with actuation section1302(FIG.13B). In some embodiments, the first balloon1202can be filled with an expansion media (e.g., saline, foam, a gas, etc.) having a temperature that is below a phase transition temperature of the shape memory component(s). Given that the shape memory component included in the actuation section1302is in a first relatively malleable phase (e.g., a martensitic or R-phase) at temperatures below the phase transition temperature (e.g., at body temperature), inflation of the first balloon1202to a size larger than dimension D1can deform the actuation section1302such that an end portion of a lumen expands and can be characterized by a second dimension D2which is larger than the first dimension D1(FIG.13A). In some methods of use, a user can elect to maintain the shunt1301with the actuation section1302in this expanded configuration characterized by dimension D2(or more precisely, a dimension similar to D2, since some rebound of the component may occur after an expanding force is removed). In such a method, the first and second balloons1202and1203may be collapsed by removing the expansion media, and catheter1200can disengage from shunt1301and be removed. In alternative scenarios, additional and/or alternative dimensional adjustments to the actuation section1302may be desired by a user. In such scenarios, additional or alternative method steps may be included. For example, as shown inFIG.13C, the first balloon1202can be expanded to enlarge an actuation section1302. Alternatively, as best seen inFIG.13D, the first balloon1202can be expanded to a size equal to or smaller than a dimension D3, which could allow balloon surfaces to make contact with or be proximate to actuation section1302without mechanically deforming it. Prior to or following delivery of the expansion media to the first balloon1202, the expansion media may be heated or otherwise energized such that the first balloon1202acts directly or indirectly as an energy coupling component that allows a shape memory component in the actuation section to be heated above a phase transformation temperature (e.g., above an R-phase or austenite start or finish temperature) and therefore move towards a manufactured heat-set geometry. Within examples, this geometry may be defined by dimension D3, which is smaller than D1and D2. In further embodiments, however, D3may be larger than D1and D2, orb e a dimension sized between or equal to either D1or D2. During actuation of the shape memory component, the actuation section1302can provide a force that deforms, deflates, or otherwise overcomes the radial outward force provided by the first balloon1202. For example, as the actuation section1302shrinks to a reduced dimension, it may provide a force that pushes expansion media out from the first balloon1202and retrograde through a lumen of catheter1200towards a proximal end of a device. In some examples, the pressure inside of the first balloon1202can be measured using pressure sensors known in the art. As the actuation section1302provides a force on the first balloon1202during a geometric change to a smaller geometry, there can be an increase in pressure measured inside of the first balloon1202. This noted increase in pressure may prompt a removal of media from the balloon indirectly (e.g, by alerting a user to perform an action such as withdrawal of media via a syringe) or directly (e.g., by opening a valve in the device to allow for media outflow). In some examples, a valve in the device can be pressure sensitive (e.g., a pressure release, or pop-off, valve) such that as a shape memory component in the actuation section1302exerts force on the first balloon1202. When pressure within the first balloon1202increases above a threshold, the valve in fluid (and, therefore, pressure) communication with the balloon media opens and relieves pressure by allowing filling media to flow out of the first balloon1202. In some embodiments, as a shape memory component of the actuation section1302is heated above a transition temperature and begins to move towards a shape set geometry that is smaller than its previous geometry, the expansion media can be slowly removed from the first balloon1202to facilitate the actuation section1302reaching its preferred geometry without excessive resistance from the first balloon1202. In some embodiments, this may result in the complete or near-complete removal of expansion media from, and thus the collapse or partial collapse of, the first balloon1202, as illustrated inFIG.13D. Throughout the energy application step(s), the second balloon1203may remain expanded and blocking blood flow through the shunt lumen, thereby reducing the cooling and energy distribution effects (e.g., conduction) known to be associated with fluid at one temperature flowing over a surface of a warmer temperature. In the above example, the first balloon1202is described to use an expansion media as the energy source and/or energy coupling mechanism, but those skilled in the art will recognize that other energy sources (e.g., radiofrequency (RF) energy, laser energy, ultrasound energy, etc.) and/or coupling mechanisms (e.g., foams, microbubbles, expelled media, direct contact, etc.) can be substituted for the expansion media without loss of novelty. FIG.14Aillustrates a distal end portion of an energy delivery catheter1400configured in accordance with a further embodiment of the present technology. The catheter1400may be similar to catheter1200described above and, accordingly, may be integrated into part of a medical device system (e.g., system101, system201) as described herein. The catheter1400includes a shaft or elongated body1401that connects proximal portions of the device (not shown) with the distal complex as illustrated. The catheter1400includes three expandable balloons: a first, central expandable balloon1402, a second, distal expandable balloon1403, and a third, proximal expandable balloon1404. The first expandable balloon1402serves primarily as an energy source and/or energy coupling mechanism for the catheter1400and distal balloon1403and proximal balloon1404serve primarily as occlusion, docking, and/or positioning mechanisms. In some additional embodiments, the distal and proximal balloons1403and1404may serve additional purposes related to energy transfer, improving the safety, speed, and/or reliability of the adjustment technique, or other purposes. In the implementation shown inFIG.14A, the distal and proximal balloons1403and1404are larger in size than the central balloon1402. In other embodiments, however, the central, distal, and/or proximal balloons1402,1403,1404may have different sizes/arrangements relative to each other. FIG.14Bis a cross-sectional view of the catheter1400interfacing with an interatrial shunt device1410that has been implanted in the septum S of a patient. The shunt1410has a generally parabolic or hourglass shape (as shown), generally cylindrical (not shown), or generally conical (not shown) and includes a central actuation section that contains one or more shape memory components1411(e.g., nitinol zig structures, etc.). The shape memory components1411may exist in a single portion of the shunt, can wrap circumferentially around the shunt structure, or be in another configuration, and can be located inside of, on the exterior of, or embedded within one or more membrane or substrate structures that define a lumen through which fluid may travel, or be positioned in some combination of these locations. InFIG.14B, the catheter1400has been positioned such that it traverses the entire lumen of shunt1410and has sections in both the RA and the LA. Both the distal balloon1403and proximal balloon1404have been expanded to a size larger than the inlet/outlet ends of shunt1410, and thus block the flow of blood into the central portion of the shunt from either heart chamber, creating an isolation zone interior to the shunt1410that limits heat sink/quenching effects both due to the flow of blood through the shunt but also due to the large thermally-conductive volume of blood present in either chamber. Interior to the shunt central balloon1402(shown in dashes) can be expanded to alter a dimension of an actuation element as described above. FIGS.15A-15Dillustrate additional embodiments of a medical system configured in accordance with the present technology. The figures have been drawn to clearly identify the specific device components associated with the present embodiments, and are not necessarily representative of the relative scale of or spatial relationships between components experienced during use. In addition, some components (e.g., guidewires, frame structures, etc.) have been omitted from the figures for clarity.FIG.15A, for example, includes a depiction of a catheter device1500(only distal end shown) that is configured to interface with an interatrial shunt1505. The shunt1505has been implanted in the septum S of a patient and includes first (e.g., RA side) anchoring elements1506, second (e.g., LA side) anchoring elements1507, actuation section1508, and other features. The catheter device1500features a concentric-style design, with outermost portion1501comprising a sheath or catheter body that encloses and/or surrounds additional aspects of the device1500. The innermost portion of catheter device1500features an adjustment catheter1503that includes one or more expandable balloons1504. Within implementations, adjustment catheter1503can include a number of ports and/or lumens, e.g., lumens intended to convey expansion media to an expandable balloon1504or ports that allow the catheter to interface with a guidewire and therefore be delivered over-the-wire as is known in the art. The catheter device1500also includes an interface feature1502that takes the form of an isolation hood. The isolation hood1502can be self-expanding (e.g., constructed at least partially of nitinol or another alloy that has been manufactured to exhibit elastic or superelastic properties at body temperature) and covered with a membrane or substrate that generally has limited to negligible short-term fluid permeability (e.g., a silicone, a urethane, a high density ePTFE, etc.). The isolation hood1502can surround the adjustment catheter1503and can be advanced to contact and/or surround a portion of the shunt. For example, the isolation hood can be advanced to contact the septal wall surrounding the actuation section1508of the shunt (e.g., as shown inFIG.15B), thereby facilitating the positional stability and alignment of the catheter device1500while isolating the actuation section from blood residing in the RA. This isolation (which, in some implementations, can be coupled with additional isolation from blood in the LA) can in some scenarios improve the safety, effectiveness, and reliability of dimensional alterations of a shape memory component located in the actuation section of the shunt as described above, and can in some instances reduce the time required to induce an energy-stimulated geometric change in the actuation section. Variation implementations of the devices, systems, and methods disclosed herein can optionally incorporate alternative features that assist with bidirectional adjustment of a dimension of an implanted medical device.FIG.16, for example, illustrates a medical system1600comprising an energy delivery catheter1601(only distal end shown) interfacing with an interatrial shunt1607. As shown, the catheter1601includes a shaft or elongated body1602and a distal complex with an expandable balloon1604(shown in an expanded operating configuration) that can act as and/or contain an energy source, actuator expansion component, and/or energy coupling mechanism. The shunt1607can be implanted into a septum S and include an actuation section that can be geometrically adjusted in either direction (i.e., either larger or smaller) via the expandable balloon1604. The catheter1601can also feature one or more distal exit ports1603through which substances (e.g., saline, contrast agent, pharmaceuticals, foams or gels, etc.) can be expelled from the device. The catheter1601can include one or more lumens (not shown) through which substances can travel between the proximal complex of the catheter (e.g., sections proximate to a handpiece outside of a patient's body during use) and the distal portions of the catheter. In some embodiments, a single lumen can transmit substances both to an exit port within an expandable balloon (not shown) and to exit port(s)1603. In other embodiments, separate lumens can be used to communicate media to the balloon1604and to exit ports1603. In implementations that contain a plurality of exit ports1603, any combination of shared or independent lumens can be utilized. Identical sub stances can be passed along multiple lumens or, alternatively, different lumens can serve as pathways for different media. In some examples, identical media may travel along different lumens, but the media traveling through each lumen may be characterized by different properties—for example saline at different temperatures. During operation of the system1600, the catheter1601can interface with shunt1607(as illustrated inFIG.16). The expandable balloon1604can be used to apply a mechanical force to a shape memory component in an actuation section of shunt1607, resulting in a mechanical deformation of the shape memory component and a corresponding change in the geometry of the shunt1607and/or shunt lumen. The expandable balloon1604can also apply energy (e.g., in the form of heat) to the shape memory component, resulting in a different geometric change as a consequence of a material phase change due to the shape memory effect, as described elsewhere herein. Prior to, during, or following the application of energy, and regardless of the expanded or deflated condition of the expandable balloon1604, media1605(e.g., saline, a foam, etc.) can be expelled from distal exit ports1603in the direction of the expandable balloon1604, actuation section (not shown), and/or shunt1607. The expelled volume of media and/or the associated ejection/streaming force is expected to at least partially prevent blood in the heart chamber from reaching the energy transfer site and acting as a heat sink or as a mechanism to wick away thermal energy via flow. In some embodiments, the expelled media can be a bioabsorbable foam that temporarily occupies the space proximate to the energy transfer site, thereby transiently providing thermal insulation to the site. In alternative embodiments, the expelled media is saline that has been heated to be warmer than body temperature that can displace the blood normally present proximate to the energy transfer site with media that is anticipated to be more insulative to the energy transfer process. In further embodiments, the temperature of the expelled media could be lower than body temperature and be intended to provide cooling to tissue and/or device areas near the energy transfer site (e.g., to provide additional protection against undesirable tissue heating). In some implementations, the balloon1604can be perforated such that media (e.g., a hot saline) is also expelled from it during certain operational conditions (e.g., when a threshold pressure inside of the balloon has been reached). It will be appreciated that the most suitable choice of expelled media, along with the temperature and other characteristics of the media, can vary in different operational scenarios and/or when using different implementations of the energy delivery catheters and/or implanted devices described herein. Referring toFIGS.17A-17E, further embodiments of energy delivery catheters for use with systems and methods described herein are disclosed.FIG.17A, for example, is a side view of a distal portion of a catheter1700, whileFIG.17Bis a side cross-sectional view of the same catheter1700.FIG.17Cillustrates a transverse cross-sectional view of the catheter1700across a portion of the catheter shaft defined by a region L. As illustrated, the catheter1700includes a catheter shaft/elongated body1701and a distal complex with an expandable multi-balloon complex or “double-balloon”1710(shown in an expanded operating configuration) that can act as and/or contain an energy source, actuator expansion component, and/or energy coupling mechanism. The multi-balloon complex1710can include an inner balloon1703and an outer balloon1702. The inner balloon1703, for example, may be located entirely inside of outer balloon1702. In other embodiments, however, the outer and inner balloons1702and1703may have a different arrangement relative to each other. Both balloons1702and1703are expandable via the transmission of media via one or more lumens (not shown) that can run between proximal and distal sections of the catheter1700. In alternate embodiments, only one of the balloons is expanded via a filling media (e.g., a liquid, a gas, a foam, a gel, etc.) and the other balloon may be expanded due to a force (i.e., a pushing or pulling force) provided via a physical attachment to the first balloon. Each balloon1702and1703may be associated with one or more independent lumens not associated with the other balloon. In other embodiments, however, each balloon1702and1703may share one or more lumens. Each balloon1702and1703may be filled or partially filled with the same media (sharing the same characteristics—i.e., temperature—or having varying characteristics) or different media. For example, the inner balloon1703can be filled with an energized media to transfer energy to an implanted medical device, and the outer balloon1702can be filled with a radiographic contrast agent so as to improve visualization with medical imaging (e.g., with fluoroscopy). Further, it is possible for one balloon to expand while the other balloon remains partially or completely unexpanded. It will be apparent to those skilled in the art that other structures may be substituted for or additionally integrated into one or more of the balloons in the multi-balloon complex. For example, an expandable metallic mesh, cage, or braid can be utilized in conjunction with one or more balloons to achieve similar functionality as described herein. In some embodiments, the inner balloon1703of the catheter1700is dimensionally similar to the outer balloon1702along at least one dimension. This arrangement is expected to help ensure inner balloon1703remains proximate to the intended interface aspects of an implanted device (e.g., proximate to the shape memory component(s) in an actuation section of a device). In the illustrated embodiment, the inner balloon1703is approximately cylindrical in shape and, along a region L (FIG.17B) of catheter shaft1701, occupies nearly the same spatial area as outer balloon1702when both balloons are in an expanded configuration. In other words, when interfaced with a circular or ovular section of an implanted device while in an expanded configuration, inner balloon1703will be located proximate to all portions of the section along its rounded perimeter. In other portions of the multi-balloon complex1710(i.e., in portions corresponding to locations along the catheter shaft1701outside of region L), the balloons may be dimensionally dissimilar. Referring toFIGS.17B and17C, in some embodiments the catheter1700can include at least one energy source1704within the inner portion of one or both of the balloons1702and1703. The energy source1704can be used to directly or indirectly transfer energy (e.g., heat) to an actuation section of an implanted device. The energy source can be, for example, a resistive heating element that can be raised in temperature by running an electrical current therethrough (e.g., via electrical circuitry connected to the energizing element (not shown) that can be included proximate to a handpiece of the catheter). Heat generated by the energy source1704can be conveyed via an energy coupling mechanism (e.g., media delivered to and causing the expansion of one or more balloons in the multi-balloon complex1710(FIGS.17A and17B)) to targeted portions of an implanted device. In some embodiments, saline can be utilized to fill/expand one or more of the balloons such that the multi-balloon complex makes contact with or becomes proximate to an actuation section of an implanted device and also serve as a medium through which heat generated by energy source1704is conveyed to the actuation section of the device. In some embodiments, the energy source1704is a metallic wire arranged to have a generally helical shape that wraps around catheter shaft1701with at least one turn, and preferably with a plurality of turns. The metallic wire is preferably comprised of a metal with a relatively high electrical resistance, for example nitinol or nickel-chromium. The wire may take on a variety of shapes (e.g., cylindrical, square, flat, etc.) in order to balance ease of manufacturing, structural considerations, and electrical and thermal characteristics. As best seenFIG.17B, for example, the energy source1704comprises a helical metallic wire that has a winding radius larger than that of the catheter shaft it encircles (i.e., the wire encircles the shaft but is offset by some distance and does not contact the shaft along the majority of the length it winds about it). One features of this design is that because it increases the surface area of wire that is in contact with an energy coupling medium, this arrangement is expected to enable more rapid heating of the medium. In other embodiments, the wire may wrap tightly about the catheter shaft. This latter configuration can result in longer heating times, but is expected to enable a slimmer profile energy delivery catheter, which may be a favorable trade-off in certain scenarios. The use of energy delivering catheters that include multi-balloon complexes (and related implementations) can offer several advantages when integrated into systems and coupled with methods of use as described herein. For example, the use of combinations of different balloon materials (e.g., using coupled compliant and non-compliant balloons) can allow some advantages of the material properties associated with each to be leveraged, which can help with alignment and efficient force transmission when using mechanical means (e.g., via expansion of one or more balloons with filling media) to alter the geometry of an actuation section. Further, when using applied heat to induce a geometry change associated with a shape memory effect, the outer balloon1702can serve as a barrier that insulates the heated inner balloon1703from blood or other tissues that would otherwise act as heat sinks that pull energy away from the targeted delivery region. In an example implementation, the outer balloon1702can be filled with an insulative foam or gel, while an inner balloon can be filled with saline that is to be heated by the energy source1704. In some embodiments, both inner and outer balloons1703and1702can be filled with saline and warmed by an energy source (e.g., energy source1704). In a further embodiment, the outer balloon1702can be filled with a cold fluid to spatially contain any temperature rises induced by energized media within inner balloon1703to the targeted interface region. An additional advantage of implementations that utilize a multi-balloon complex is that mechanical and thermal energy transfer mechanisms are expected to be jointly improved. For example, outer balloon1702with a larger volume and surface area can ensure proper contact, stability, and alignment with an actuation section of an implanted device, and also provide much of the force required to expand the geometry of the actuation section mechanically. Inner balloon1703with a smaller volume and surface area will hold a relatively smaller volume of expanding/filling media, which will be energized/heated more rapidly compared to a larger volume of media that could be required when utilizing single balloon approaches. FIG.17Dillustrates a side cross-sectional view of a catheter1750configured in accordance with still another embodiment of the present technology, andFIG.17Eillustrates a transverse cross-sectional view of the catheter1750ofFIG.17Dacross a portion of the catheter shaft. Referring toFIGS.17D and17Etogether, the catheter1750is substantially equivalent to catheter1700but includes some varied features that may be useful in some scenarios. The catheter1750includes a shaft or elongated portion1751and features a distal balloon complex1760that includes an outer balloon1752and an inner balloon1753. When in an expanded configuration, outer balloon1752can assume a roughly spherical shape when not deformed by outside forces. When in an expanded configuration, inner balloon1753can be similarly-sized and shaped as outer balloon1752along one dimension (e.g., along the dimension parallel to the catheter shaft), but remain smaller than outer balloon1752in other dimensions. This dual balloon configuration results in an approximately toroidal shaped space being created between the two balloons when both are expanded. The catheter1750further comprises an energy source1754that can be coupled to or otherwise closely aligned with the exterior of inner balloon1753such that the energy source1754is oriented in the open toroidal space. The energy source1754can be, for example, an electrode, a resistive wire, a metallic mesh, a laser, an electromagnetic or acoustic energy source, an electromagnetic energy transmission coil, or another suitable energy source known to those skilled in the art. In some embodiments, an electrode or wire-based energy source can be comprised partially or entirely of a superelastic material, and can be machined in to have a zig-zag type pattern when catheter1750and distal balloon complex1760are in a collapsed or low-profile (i.e., slim) configuration (e.g., for insertion into the body). Such material compositions and component designs, along with similar variants, can allow the energy source1754to remain functional as it is expanded between configurations of different geometries. In one operational example, outer balloon1752can be expanded with an electrically and/or thermally conductive medium and thereby either facilitate the conveyance of energy to an actuation section of an implant for direct heating or serve as an energy coupling mechanism to conduct heat indirectly to the actuation section. Such a configuration is expected to have several advantages. For example, the implementation shown inFIGS.17D and17Eallows for the energy source1754comprised of an electrically conductive wire, one or more electrodes, or similar components to be positioned very close to a shape memory component in an implanted device, while keeping the energy source electrically isolated from the patient's body. Further, the toroidal volume in the space between balloons1752and1753is expected to be much smaller than the volume of either individual balloon1752and1753, which can allow for the balloon(s) to be filled/expanded with a smaller volume of media (enabling the media to be heated with lower overall power delivered), which has the benefit of shorter time requirements to heat the media, smaller energy sources, or both, as described above. Other stated advantages as described above, such as isolating certain portions of the energy delivery catheter from blood flow or from large pools of blood, can also be achieved via catheter1750or its variants. For the presently disclosed devices and systems, the actuation section of an implant can be in a number of potential locations. For example, for an interatrial shunt device, an actuation section can reside in the LA, in the RA, or in a more central portion at or near a septal wall or septal opening. With specific regard to an interatrial shunt device, it may be preferable to have an actuation section that is adjustable in at least one dimension due to the heating of a shape memory component to reside in a location remote from native cardiac tissues (e.g., in an LA or RA). Such a location can reduce the risk of unwanted collateral tissue heating during the transfer of energy from an energy source (e.g., an internal source or an external source) to the shape memory component. Further, the native septal tissue may complicate the functionality of a nearby or integrated actuation section. For instance, the septal tissue can provide resistance to the expansion of a shape memory component during an expansion operation, and following this expansion can provide a radial compressive force that over time could alter the dimension of the actuation section as the septal tissue rebounds/recovers from the expansion operation. Further, during an operation that reduces a dimension of an actuation section that is nearby or integrated into a septal wall, it is possible to create separation between the actuation section or other portions of the device from the septum, which could result in leaks around the device and/or actuation section, or create stagnation zones that elevate thrombus risk. Despite these concerns, some implementations of interatrial shunts and other implantable devices may require and/or benefit from actuation sections that are nearby or integrated into native tissues (e.g., in a relatively central portion of a shunt at or near a septal wall or septal opening). Various device configurations described herein via representative examples are expected to improve the efficacy, safety, and/or practicality of these implementations. It will be clear to those skilled in the art that the configurations as described herein are also expected to be useful, in whole or in part, in implementations of devices that have actuation sections in any location relative to the device or nearby tissues. Devices configured in accordance with the present technology are also expected to provide combination heating and cooling treatments to tissues and/or structures. In such examples, the application of heating and cooling energy can occur simultaneously or in any sequence relative to one another. Such configurations are expected to be useful in protecting tissues or critical device components from unwanted collateral heating during a time when energy is being transferred to a device to heat a shape memory component in order to induce a material phase change and a corresponding geometric alteration. Some such examples have already been described (e.g., the implementation depicted inFIG.16). Other such examples can include variations of implementations as previously described herein. For instance, with reference toFIG.12andFIGS.13A-13D, the second balloon1203can be filled with a media that is cooler than body temperature. In additional embodiments, the second balloon1203can be perforated with openings (for example, openings aimed towards the septal wall S and/or the lumen of shunt1301—i.e., in the direction of the shape memory component) that can expel a cooled medium (e.g., cold saline) towards the region of targeted energy transfer. In additional embodiments, an energy source or an energy transfer medium contacts a shape memory component directly, effectively transmitting heat and limiting the impact of cooling effects provided by perforated the second balloon1203. However, other regions (e.g., blood, tissue, other portions of the device) that do not contact the energy source or energy transfer medium directly may receive meaningful cooling effects as a result of a low temperature media being expelled from the second balloon1203. In some scenarios, this can allow for increased insulation of non-targeted areas from thermal effects while minimizing the impact on procedure time or efficiency related to heating targeted areas. Within examples, various mechanisms can be utilized to directly or indirectly provide a source of cooling thermal energy (e.g., via injection of cold substances, via evaporative cooling, via chemical cooling/endothermic chemical reactions, or via other sources). Variation examples of energy sources associated with the presently disclosed devices and systems can include thermoelectric (i.e., Peltier) devices. As known to those skilled in the art, thermoelectric cooling devices create cold temperatures in response to electrical currents applied to structures that are constructed to include a junction between two different types of materials. As a consequence of the creation of cold temperatures, a relatively large amount of heat is generally created on the opposing side of the structure. Within an implementation, a thermoelectric device could be utilized to simultaneously provide warming thermal energy to a targeted site (e.g., to a shape memory component) while providing cooling thermal energy to a different region. In further embodiments, cooling and heating energy may be applied simultaneously to a region, but due to the material properties of a shape memory component relative to those of surrounding structures, temperature elevation (and, thus, a material phase change) can still occur. In one example, a system includes a catheter with an energy source (e.g., one or more radiofrequency energy electrodes) attached to an exterior of an expandable balloon. The balloon can be expanded to make contact with an actuation section of an implanted device and/or surrounding tissues or device structures by filling it with a low temperature media. Through this process, contacted structures are pre-cooled to a temperature lower than body temperature. In one example, radiofrequency energy (provided by another component of the system, for example an RF generator outside of the patient's body) is delivered to the target region via the electrodes affixed to the exterior of the balloon. Without wishing to be bound by theory, due to direct contact/interface and the resistive/thermal properties of a shape memory component relative to surround structures, an applied current may more rapidly induce a temperature elevation in a shape memory component than surrounding tissues or structures. Therefore, a shape memory effect could be induced before temperatures in the surrounding pre-cooled tissues were elevated to undesirable levels. Systems and devices configured in accordance with the present technology are also expected to help improve mechanical, positional, and/or other functional aspects of an implanted device having an actuation section nearby or integrated into a septal wall or another tissue. For example, some implementations of the present technology are expected to help prevent destabilization or leakage associated with an interatrial shunt that has been reduced in a dimension at a location proximate to its contact or securement point with a septal wall. With reference toFIGS.18A-18C, an example interatrial shunt1800includes a first self-expanding end section1805, a second self-expanding end section1806, and a centrally-located actuation section1888that includes one or more shape memory components1811that have been manufactured such that they are relatively malleable at body temperature (i.e., the Af phase transition temperature of the material is above body temperature). In particular,FIG.18Ais partially schematic side view of shunt1800implanted into a septal wall S in an expanded operating configuration,FIG.18Bis a side view of the shunt1800loaded into delivery catheter1870while in a low-profile, collapsed delivery configuration, andFIG.18Cis a transverse view of the shunt1800as seen from the LA looking toward the septal wall S after the shunt1800is implanted and in its operating configuration. Referring toFIGS.18A-18Ctogether, first and second self-expanding sections1805and1806of the shunt can be comprised of a metallic frame where at least some sections are constructed of superelastic materials (e.g., Nitinol), with the frame being lined with, coated with, encased within, or otherwise integrated with a membrane or substrate material (e.g., a silicone, ePTFE, etc.) that defines a channel through which blood may flow. The first and second self-expanding sections1805and1806of the shunt can be comprised, for example, of a metallic frame where at least some sections are constructed of conventional linear-elastic-plastic materials (e.g stainless steel, titanium, cobalt chromium), designed in such a way to achieve shape-memory through elastic recovery (e.g. through a spring-like design), with the frame being integrated with a membrane as described above. The centrally-located actuation section1888may be joined or mechanically-coupled to the first and second self-expanding sections1805and1806such that the three sections form a continuous channel through which fluids may pass. Within examples, the frames of the first and second self-expanding1805and1806sections and the centrally-located section are composed of a nitinol unibody that spans the entirety of the three sections, with the central frame section being heat-treated and/or otherwise conditioned differently from the end sections during manufacturing such that the material properties of the central frame section differ from those of the frame elements in the first and second self-expanding sections1805and1806. The shape memory components1811(in the centrally-located actuation section1888) can be part of a frame structure, can be separate from a frame structure, can replace a frame structure, or can interface with the other components of shunt1800in any other way. The shunt1800also includes first anchoring element(s)1807and second anchoring element(s)1808. In some embodiments, the anchoring elements1807and1808are also composed of a superelastic material. The first and second anchoring element(s)1807and1808are shaped/designed so as to grab a variably thick septal wall from opposing sides, and positioned along the body of shunt1800such that the first anchoring element(s)1807and second anchoring element(s)1808exist on opposite sides of the septal wall once shunt1800has been deployed into an operating configuration. As illustrated inFIG.18B, shunt1800can be collapsed (e.g., manually, via an introducer or crimping tool, etc.) into a slim profile delivery configuration and placed within a delivery catheter1870. When released from the delivery catheter1870for implantation into the septum S of a patient (FIG.18A), the first and second self-expanding sections1805and1806, and first and second anchoring element(s)1807and1808self-deploy into an operating configuration, while the actuation section1888can largely or entirely maintain its slim delivery configuration due to its lack of self-expanding properties at body temperature. In examples where the first self-expanding section1805and/or the second self-expanding section1806are mechanically-coupled to the central actuation section1888, a portion of the forces related to the elastic or superelastic recovery of these end sections into their preferred (i.e., heat set, as-manufactured) geometry can be conveyed to the central actuation section and thereby manipulate the central section into a suitable operating configuration. In other implementations of systems and methods, the central actuation section1888may be required to be forced open (e.g., by an initial balloon expansion that is an integral step in a device delivery procedure) to achieve its desired operating configuration. In variation embodiments, the as-delivered geometry of the central actuation section is suitable for use. As illustrated inFIG.18A, in an operating configuration shunt1800assumes an hourglass type shape, with relatively wide flared end sections that serve as inlets/outlets for blood flow that taper down to a centrally-located smaller neck region that interfaces with the septal wall. Radial outward force provided by the central section1888help stabilize the position of shunt1800. The flared geometry of end sections1805and1806further anchor the shunt in place, as the size of the shunt body exceeds the size of the transseptal opening that is created during device delivery. In a non-adjustable configuration, the geometry of the frame section of shunt1800can be sufficient to ensure proper shunt functionality and prevent migration. However, with an adjustable shunt—particularly with an adjustable shunt that can be made smaller in a geometric dimension—additional anchoring elements1807and1808can improve the function and stability of the device. The first and second anchoring element(s)1807and1808can be attached to or otherwise integrated with the shunt body (e.g., via welding, sutures, adhesives, shared membrane integration, etc.) and configured to have at least some sections that will lie approximately flush with the sides of the septal wall when the shunt1800is in an operating configuration, as shown in FIGS. VA and VC. In variations that included materials and/or surface treatments to allow/promote tissue-growth, once implanted in this configuration, after a period of time (e.g., 6-12 months) it is expected that the first and second anchoring elements1807and1808will experience tissue overgrowth and/or endothelialization, and therefore become embedded in the septal wall. This design is expected to be advantageous as, over time, it allows for more effective structural integration of the shunt1800into the septal wall. Accordingly, if at a time several months after implantation (e.g., once anchoring elements have grown into the septal wall) a user wished to alter the geometry of the shunt in a way that reduced a dimension at or near the central actuation section1888, the adjustment procedure is less likely to create gaps between the septal wall and the shunt, thereby preventing leaks around the shunt or stasis areas of low blood flow that can lead to thrombus or emboli. More specifically, in many cases it is expected that a shunt device would be placed into the septal wall in the region of the fossa ovalis, and anchoring elements1807-1808would interface at least in part with thin and relatively stretchable primum tissue. Accordingly, the force generated by shape memory components1811in the actuation section1888of shunt1800as they change material phase and move towards a preferred heat-set geometry can, in many instances, overcome any counterforce enacted by the primum, thereby stretching the primum towards the shunt body as it moves. Within example clinical scenarios, this can facilitate the maintenance of a tight seal between the shunt device and the surrounding tissue, which is expected to further improve performance and increase the safety profile of the device. A number of implementations of energy delivery catheters described herein include expandable balloons that can be used to apply mechanical force to an actuation section of an implantable device to cause it to deform geometrically (e.g., expand or contract in a dimension) and/or be used to provide or convey heat to a shape memory component within an actuation section to cause a change in geometry related to a material phase change. In some scenarios, preferable implementations can utilize a compliant balloon (i.e., constructed from silicone, a polyurethane, or similar materials) that, after expansion and subsequent collapse, returns to a thin profile that is positioned tight and close to the body of a catheter shaft. Such a configuration may allow for smaller diameter delivery tools (e.g., catheters, sheaths, introducers, etc.) relative to the use of a non-compliant balloon, which in general will not automatically regain a thin profile once it has been expanded out of an initially folded configuration. A challenge with using compliant balloons to interface with implanted medical devices, particularly devices that have an actuation section with a small length along the axis of a catheter shaft, is that alignment between the balloon and the targeted interface area can be difficult. Further, as a compliant balloon expands to engage such a structure smaller in length the balloon, it can tend to “buckle” outward around the end edges of a structure instead of expanding outward radially so as to apply sufficient concentrated force to the structure to cause a mechanical deformation. Utilization of specific geometry balloons can facilitate overcoming such challenges. For example, a balloon that is large radially in dimensions outward from the catheter body compared to its length along the catheter body can be preferable for use. Such a balloon geometry is inherently constrained to a fixed length along the dimension of the catheter shaft, which is expected to help prevent excess end-buckling as it expands to engage a similar length structure. In one example, an energy delivery catheter includes a compliant balloon with approximate dimensions of 10 mm diameter×40 mm long such that, in an expanded configuration, the balloon is roughly shaped as a cylinder. In some embodiments, the wall thickness of one or more balloons utilized in a catheter as described herein may vary across different aspects of the balloon, thereby altering the expansion and mechanical properties of the balloon in a way to better enable functionality with engaging and deforming an implantable device. In several embodiments, balloons can be injection molded to allow for strong manufacturing yield and precision while creating a balloon with variable wall thickness. An energy delivery catheter configured in accordance with the present technology can utilize a tapered actuator expansion component (e.g., a tapered balloon, a tapered metallic mesh, etc.). The tapered component can move between a relatively flat and uniform delivery configuration (e.g., one in which it resides entirely in close proximity with a catheter shaft or body), and an expanded operating configuration where it has a tapered shape that in a first location extends a first distance from the catheter shaft and in a second location extends a second distance from the catheter shaft. In some examples, the tapered component can include one or more marker bands (e.g., radiopaque markers, echogenic markers, etc.) positioned at points along the taper. For example, marker bands placed at locations where the taper extends 1 mm, 2 mm, 3 mm, etc. away from the catheter shaft. Any number of marker bands at any number of intervals can be utilized. During a procedure involving the mechanical expansion of an actuation section of an implanted device, a catheter could first interface with the device while in its slimmer low-profile delivery configuration. For instance, a user could place the distal end of the catheter through the lumen of an interatrial shunt. The tapered expansion component could then be expanded entirely or partially into an operating configuration. In some examples, the taper direction is such that the expansion component becomes larger (i.e., expands more radially from a catheter shaft) as it becomes further away from the actuation section of the device when positioned as currently described. To enlarge the actuation section, a user could begin to retract the catheter such that the tapered section interfaces with a relatively malleable component and forces it to expand. The degree of expansion is directly related to the size of the tapered expansion component at the interface point with the actuation section, which is controlled by the degree to which a user retracts the catheter with the expansion component expanded into an operating configuration. Medical imaging (e.g., fluoroscopy, ultrasound, etc.) can help guide the user by showing positions of marker bands on the tapered component relative to the position of the actuation section (which can be generally visible, all or in part, with imaging). Once a user has retracted the catheter sufficiently so as to position the tapered expansion component properly in order to create the desired amount of dilation of the actuation section, the user can move the tapered component back into its slimmer delivery configuration for removal. As one skilled in the art will recognize, the above procedure steps are intended to be illustrative in nature and are not exhaustive, and other steps that are complimentary, substitutive, or additive to the above procedure as described can be included. The devices and systems described herein can feature catheters with one or more lumens. Lumens can serve as passageways for components of a delivery or adjustment system (e.g, for a guidewire), be used to transport media between proximal and distal ends of the catheter, and/or for other purposes. In some implementations, a lumen in a catheter can be unidirectional in nature—in other words, it serves as a conduit intended to pass media that moves strictly in one manner relative to the catheter (e.g., from a proximal end towards a distal end, from a distal end towards a proximal end, etc.). In such implementations, catheters can have a plurality of lumens, e.g., lumens to provide expansion media to expandable balloons and lumens to remove media from expandable balloons. In other implementations, lumens can be bidirectional and capable of moving media back and forth within the catheter. For example, a syringe can interface with an entry port near a proximal end of the catheter, and media can be delivered or removed from the distal ends of the catheter depending on whether a user is depressing or withdrawing the syringe plunger. In another example, media can be provided into a catheter via a first means (e.g., a syringe, an IV bag, etc.) and be removed via a different means (e.g., via a one-way valve that diverts retrograde flow of media towards an exit port). A number of the devices, systems, and methods described herein involve changing a temperature in a portion of a catheter, implanted device, or in another region. In some implementations, it is desirable to measure, display/communicate, or control temperature changes induced in a portion of the system. In some examples, direct or indirect feedback loops can be utilized to control temperatures in regions of the system, which facilitates both ensuring the temperatures meet their targeted levels as well as ensuring temperatures remain within safe operating limits. In an example, a temperature sensor (e.g., a thermocouple, a thermistor circuit, etc.) can be included at or near a portion of the system where a temperature change is induced. Measured temperatures can be displayed to a user (e.g., on a display proximate to the handpiece or elsewhere outside of the patient's body), or indicators depicting the general state of the temperature (e.g. green indicator for favorable temperature, red indicator for undesirable temperature, etc.) can be provided. In some examples, circuitry such as an NTC thermostat can be used to regulate temperature in a temperature-controlled element. B. Interatrial Shunts for Treatment of Heart Failure In some embodiments, the systems and methods described herein are used for treating heart failure. Heart failure can be classified into one of at least two categories based upon the ejection fraction a patient experiences: (1) heart failure with reduced ejection fraction (HFpEF), historically referred to as diastolic heart failure or (2) heart failure with preserved ejection fraction (HFrEF), historically referred to as systolic heart failure. One definition of HFrEF is a left ventricular ejection fraction lower than 35%-40%. Though related, the underlying pathophysiology and the treatment regimens for each heart failure classification may vary considerably. For example, while there are established pharmaceutical therapies that can help treat the symptoms of HFrEF, and at times slow or reverse the progression of the disease, there are limited available pharmaceutical therapies for HFpEF with only questionable efficacy. In heart failure patients, abnormal function in the left ventricle (LV) leads to pressure build-up in the LA. This leads directly to higher pressures in the pulmonary venous system, which feeds the LA. Elevated pulmonary venous pressures push fluid out of capillaries and into the lungs. This fluid build-up leads to pulmonary congestion and many of the symptoms of heart failure, including shortness of breath and signs of exertion with even mild physical activity. Risk factors for HF include renal dysfunction, hypertension, hyperlipidemia, diabetes, smoking, obesity, old age, and obstructive sleep apnea. HF patients can have increased stiffness of the LV which causes a decrease in left ventricular relaxation during diastole resulting in increased pressure and inadequate filling of the ventricle. HF patients may also have an increased risk for atrial fibrillation and pulmonary hypertension, and typically have other comorbidities that can complicate treatment options. Interatrial shunts have recently been proposed as a way to reduce elevated left atrial pressure, and this emerging class of cardiovascular therapeutic interventions has been demonstrated to have significant clinical promise.FIG.19shows the conventional placement of a shunt in the septal wall between the LA and RA. Most conventional interatrial shunts (e.g., shunt1900) involve creating a hole or inserting a structure with a lumen into the atrial septal wall, thereby creating a fluid communication pathway between the LA and the RA. As such, elevated left atrial pressure may be partially relieved by unloading the LA into the RA. In early clinical trials, this approach has been shown to improve symptoms of heart failure. One challenge with many conventional interatrial shunts is determining the most appropriate size and shape of the shunt lumen. A lumen that is too small may not adequately unload the LA and relieve symptoms; a lumen that is too large may overload the RA and right heart more generally, creating new problems for the patient. Moreover, the relationship between pressure reduction and clinical outcomes and the degree of pressure reduction required for optimized outcomes is still not fully understood, in part because the pathophysiology for HFpEF (and to a lesser extent, HFrEF) is not completely understood. As such, clinicians are forced to take a best guess at selecting the appropriately sized shunt (based on limited clinical evidence) and generally cannot adjust the sizing over time. Worse, clinicians must select the size of the shunt based on general factors (e.g., the size of the patient's anatomical structures, the patient's hemodynamic measurements taken at one snapshot in time, etc.) and/or the design of available devices rather than the individual patient's health and anticipated response. With many such traditional devices, the clinician does not have the ability to adjust or titrate the therapy once the device is implanted, for example, in response to changing patient conditions such as progression of disease. By contrast, interatrial shunting systems configured in accordance with embodiments of the present technology allow a clinician to select shunt size—perioperatively or post-implant—based on the patient and, as discussed above with respect toFIGS.1-6B, allow for non-invasive monitoring of lumen geometry to determine whether lumen adjustments would be beneficial and/or confirm whether lumen adjustments were successful. As one of skill in the art will appreciate from the disclosure herein, various features of the methods and systems described above can be omitted without deviating from the scope of the present technology. Likewise, additional features not explicitly described above may be added to the methods and systems without deviating from the scope of the present technology. Accordingly, the methods and systems described herein are not limited to those configurations expressly identified, but rather encompasses variations and alterations of the described methods and systems. Moreover, the following paragraphs provide additional description of various aspects of the present technology. One skilled in the art will appreciate that the following aspects can be incorporated into any of the methods and systems described above. CONCLUSION Embodiments of the present disclosure may include some or all of the following components: a battery, supercapacitor, or other suitable power source; a microcontroller, FPGA, ASIC, or other programmable component or system capable of storing and executing software and/or firmware that drives operation of an implant; memory such as RAM or ROM to store data and/or software/firmware associated with an implant and/or its operation; wireless communication hardware such as an antenna system configured to transmit via Bluetooth, WiFi, or other protocols and at other frequencies, as is known in the art; energy harvesting means, for example a coil or antenna which is capable of receiving and/or reading an externally-provided signal which may be used to power the device, charge a battery, initiate a reading from a sensor, or for other purposes. Embodiments may also include one or more sensors, such as pressure sensors, impedance sensors, accelerometers, force/strain sensors, temperature sensors, flow sensors, optical sensors, cameras, microphones or other acoustic sensors, ultrasonic sensors, ECG or other cardiac rhythm sensors, SpO2 and other sensors adapted to measure tissue and/or blood gas levels, blood volume sensors, and other sensors known to those who are skilled in the art. Embodiments may include portions that are radiopaque and/or ultrasonically reflective to facilitate image-guided implantation or image guided procedures using techniques such as fluoroscopy, ultrasonography, or other imaging methods. Embodiments of the system may include specialized delivery catheters/systems that are adapted to deliver an implant and/or carry out a procedure. Systems may include components such as guidewires, sheaths, dilators, and multiple delivery catheters. Components may be exchanged via over-the-wire, rapid exchange, combination, or other approaches. Embodiments of the present disclosure may be implemented as computer-executable instructions, such as routines executed by a general-purpose computer, a personal computer, a server, embedded computer, or other computing system. The present technology can also be embodied in a special purpose computer or data processor that is specifically programmed, configured, or constructed to perform one or more of the computer-executable instructions explained in detail herein. The terms “computer” and “computing device,” as used generally herein, refer to devices that have a processor and non-transitory memory, as well as any data processor or any device capable of communicating with a network. Data processors include programmable general-purpose or special-purpose microprocessors, programmable controllers, ASICs, programming logic devices (PLDs), or the like, or a combination of such devices. Computer-executable instructions may be stored in memory, such as RAM, ROM, flash memory, or the like, or a combination of such components. Computer-executable instructions may also be stored in one or more storage devices, such as magnetic or optical-based disks, flash memory devices, or any other type of non-volatile storage medium or non-transitory medium for data. Computer-executable instructions may include one or more program modules, which include routines, programs, objects, components, data structures, and so on that perform particular tasks or implement particular abstract data types. The above detailed description of embodiments of the technology are not intended to be exhaustive or to limit the technology to the precise forms disclosed above. Although specific embodiments of, and examples for, the technology are described above for illustrative purposes, various equivalent modifications are possible within the scope of the technology as those skilled in the relevant art will recognize. For example, although steps are presented in a given order, alternative embodiments may perform steps in a different order. The various embodiments described herein may also be combined to provide further embodiments. For example, although this disclosure has been written to describe devices that are generally described as being used to create a path of fluid communication between the LA and RA, the LV and the right ventricle (RV), or the LA and the coronary sinus, it should be appreciated that similar embodiments could be utilized for shunts between other chambers of heart or for shunts in other regions of the body. Furthermore, while various embodiments of the technology described herein are directed to implantable shunts, it will be appreciated that the technology described in the present disclosure may also be utilized with a variety of different implantable medical devices in addition to shunts. From the foregoing, it will be appreciated that specific embodiments of the technology have been described herein for purposes of illustration, but well-known structures and functions have not been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments of the technology. Where the context permits, singular or plural terms may also include the plural or singular term, respectively. Unless the context clearly requires otherwise, throughout the description and the examples, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including but not limited to.” As used herein, the terms “connected,” “coupled,” or any variant thereof, means any connection or coupling, either direct or indirect, between two or more elements; the coupling of connection between the elements can be physical, logical, or a combination thereof. Additionally, the words “herein,” “above,” “below,” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the above Detailed Description using the singular or plural number may also include the plural or singular number respectively. As used herein, the phrase “and/or” as in “A and/or B” refers to A alone, B alone, and A and B. Additionally, the term “comprising” is used throughout to mean including at least the recited feature(s) such that any greater number of the same feature and/or additional types of other features are not precluded. It will also be appreciated that specific embodiments have been described herein for purposes of illustration, but that various modifications may be made without deviating from the technology. Further, while advantages associated with some embodiments of the technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the technology. Accordingly, the disclosure and associated technology can encompass other embodiments not expressly shown or described herein.

11857199

DETAILED DESCRIPTION I. First Embodiment FIG.1illustrates a surgical reciprocating saw30to which a complementary reciprocating blade cartridge80is removably attached. The saw30has a pistol shaped body or housing32. The saw housing32includes a grip34. A barrel36is formed integrally with handgrip34. The barrel36extends proximally, rearwardly, from and distally forward of the handgrip34. (Here, “proximally” is understood to mean towards the surgeon holding the saw30, away from the surgical site to which the blade cartridge80is applied. “Distally” is understood to mean away from the surgeon and towards the site to which the blade cartridge80is applied.) A nose38projects forward from the barrel36at a distal end of the housing32. Internal to the saw barrel36is a motor, represented by a dashed rectangle40and a reciprocating shaft, represented by dashed rectangle46. A transmission, represented by dashed rectangle44, is located between the motor40and reciprocating shaft46. The transmission converts the rotational movement of the motor rotor into motion that reciprocates the shaft back and forth. Here “reciprocation” is understood to mean a repetitive proximal-to-distal-to-proximal motion along the longitudinal axis of the component under discussion. The distal end of the reciprocating shaft46is provided with engagement features that facilitate the removable coupling of the below discussed cartridge rack112to the shaft. The exact structure of these engagement features are not part of the invention, and may be readily provided by one skilled in the art. By way of an example, the shaft46may be provided with openings designed to receive holding features, e.g., complementary components, integral with the rack. A chuck, represented by dashed ring47, may be fitted to the distal end of the shaft. The chuck47may hold the holding features integral with the rack112to the shaft. The motor40internal to the saw may be a DC motor. A battery (not illustrated) may be attached to the base of the saw handgrip34. A trigger48extends forward from the distally directed face of the handgrip34. Internal to the handgrip is a control module represented by dashed rectangle50. The control module50is configured to control the sourcing of the current from the battery or other power supply to the motor40. The control module also includes a transducer that monitors the actuation of the trigger48. Based on the actuation of the trigger48, the control module50regulates the application of current to the motor40so as to regulate the actuation of the saw30and by extension, the actuation of the blade cartridge80. Many versions of saw30are configured to reciprocate a conventional reciprocating saw blade (not illustrated). The chuck47may be designed to hold a conventional, i.e. prior art, reciprocating saw blade (not illustrated) to reciprocating shaft46so the blade can be reciprocated by the shaft46. An attachment52, seen best inFIG.2andFIG.3, is removably secured to the saw nose38. The attachment52, together with the saw30and the blade cartridge80, may collectively comprise a first example saw system. The attachment52releasably holds the below described bar82of the blade cartridge80to the saw30. Attachment52includes two shells54. Shells54form the body of the attachment52. Each shell54includes a planar base56and two wings58that extend outwardly from opposed sides of the base56. Each shell54is shaped so that as the wings58extends away from the shell base, the wings curve away from the base. When the saw30is assembled, shells54are placed on the opposed sides of the nose38so the ends of the wings58of each shell54face the ends of the wings of the other shell. Bolts60extends through each wing58to the opposed adjacent wings. Bolts60clamp the shells54together, the bolts and shells collectively defining a clamping assembly, i.e., an example first coupling feature, to hold the shells54around the opposed sides of the nose38. Shells54and bolts60thus releasably hold the attachment52static to the nose38. A hand64, also part of the attachment52, extends distally forward from each shell54. Each hand64includes a rectangular palm66, one palm identified. Palms66are dimensioned to seat over the exposed surface of the shell54from which the hand64extends. Screws74hold each palm66to the associated shell54. (Not identified with reference numbers are the openings in the shells54and hands64through which the screws74extend. A finger68, also part of each hand64, extends forward from each palm66. Each finger68has a main section (not identified) that extends along a longitudinal axis that is parallel to the proximal-to-distal longitudinal axis through the saw barrel36. Each finger68has a tip70that extends perpendicularly to the longitudinal axis of the main section of the finger. A small rib72, an example second coupling feature, protrudes forward from end face of each finger tip70. The clamping assembly58and60is arranged so that when the clamping assembly is fitted to the saw, the opposed ribs72face each other. FromFIGS.4and5it can be seen that the reciprocating blade cartridge80includes a static bar82in which a rack112is moveably mounted. Bar82includes two plates84. The plates84are generally rectangular in shape. Each plate84is further formed so as to have between the distally directed face86and the top face90a transition face88. InFIG.5the edges of faces86,88, and90are identified. Each transition face88is tapered in that the face88angles both upwardly as the face extends proximally away from the associated distally directed face86. Each plate84may be formed with plural slots. A first slot, slot92, an example first holding feature, for removably holding the bar82static to the saw30, is formed in the bar so as to be forward of the proximal end of the plate84. The plates84are formed so that slots92extend along axes that are perpendicular to the proximal-to-distal longitudinal axes through the plates. Each slot92is dimensioned to receive a separate one of the ribs72integral with the finger tips70and the ribs72are likewise dimensioned to seat in the slots92. The second slot, i.e., a debris slot94, formed in each plate84is located immediately proximal to the distal and transition faces88and90, of the plates84. Each slot94thus has a first section that adjacent the plate distal face that is parallel to slot92and a section that extends diagonally away from the first section. The second section of each slot94extends parallel to the transition face88of the plate84in which the slot94is formed. The cartridge bar82also includes a spacer98that is sandwiched between the plates84. Spacer98includes an elongated beam102. The beam102has three sections, individual sections not identified with reference numbers. A first section of the beam102extends distally from the proximal end of the plates92so as to be flush with the top faces90of the plates. A second section of the beam102, as it extends forward from the first section, angles downwardly so as to be flush with the transition faces88of the plates84. The third section of the beam102extends downwardly from the second section so as to be flush with the distal faces86of the plates84. Spacer98also has two webs104, one web being identified inFIGS.5and6with reference number104. Webs104extend perpendicularly away from the first section of the beam102. Webs104are parallel. The foot106, one foot identified also part of spacer98, is located at the end of each web104. Feet106are parallel to the first section of the beam102. Each foot106extends both proximally away from and distally away from the web104with which the foot is integral. When the cartridge80is assembled, spacer98is welded between the plates84. InFIG.4the weld lines108formed by the penetration welding of one plate84to the underlying webs104and feet106are seen. Rack112includes a base118. The base118is dimensioned to move in the space within the bar82between the plates84and around the web104and feet106of the spacer98. Not identified with reference numbers are the top and distally directed surfaces of the rack base118. Likewise not identified is the transition surface between the top and distally directed surfaces. The rack base118is formed with two T-shaped openings, i.e., guide slots,120. Each opening120has a center section that is wider in width than the proximal to distal width across the webs104. The end section of each opening120is longer in length than the length of the spacer feet106. When the cartridge80is assembled, each spacer web104and associated foot106seats in one of the openings120in the rack base118. Owing to the dimensioning of the components forming the cartridge, it should be understood that the rack112is able to move longitudinally back and forth in the bar82. A tail114, also part of the rack112, extends proximally from the base118so as to extend out of the bar82. The tail has features, i.e., second holding features, that facilitate the removable coupling of the tail to the reciprocating shaft46internal to the saw30. The tail may be planar in shape, and has a top to bottom height, less than the same dimension of the base. Further, the tail may be formed so that two tabs116extend from the opposed top and bottom sides of the tail. Tabs116are diametrically opposed to each other relative to the proximal to distal longitudinal axis through the tail114. Rack112also has a head124that extends outwardly from the base118. The head124extends outwardly from the side of the base opposite the side of the base in which openings120are formed. The rack112is formed so that when the cartridge80is assembled, head124is located outside of and immediately adjacent the bottom of the bar, the portion of the rack opposite the plate top faces90. The head124is formed so as to have teeth126. The teeth126extend linearly, proximally to distally, along the head. The head and, more particularly the teeth have a side-to-side width that is greater than the thickness between the opposed major faces of the base of the rack112. More specifically, the teeth have a width such that the kerf cut by the teeth can accommodate cartridge bar82. This means that the teeth have a side to side width that is at least 0.2 mm greater than the side to side thickness across bar82. This saw system is prepared for use by coupling the cartridge80to the saw30. An initial step of this process is the coupling of the rack tail114to the reciprocating shaft46internal to the saw30. Tail114thus functions as the drive link that includes the second holding features and connects the reciprocating shaft46of the saw30to the rest of the rack112as may be done with the chuck47. The clamp assembly hands64are secured over the cartridge so that the ribs72integral with the arms seat in slots92formed in the cartridge bar82. This completes the removable attachment of the cartridge80to the saw30. The saw30and cartridge80are ready for use. The saw30and cartridge80are used by positioning the cartridge teeth126adjacent the tissue, typically bone, in which the cut is to be formed. The trigger48is depressed. The control module50, in response to the detecting that depression of the trigger18, actuates the motor40. The actuation of the motor40results in the reciprocation of the reciprocating shaft46internal to the saw30. The movement of the shaft46causes a like linear reciprocal movement of the rack112. It should be appreciated that, as the rack112reciprocates, feet106internal to the bar82, hold the rack112in the bar82. The teeth126are pressed against the tissue to be cut. The reciprocation of the teeth126when pressed against the tissue result in the teeth forming the desired cut in the tissue. When the saw30is used to cut tissue, debris formed in the cutting process enter the space between the bar plates94. The movement of the rack112forces the debris out of the bar through slots94. This prevents the debris from clogging the inside of the bar82to such an extent that the debris impede the reciprocation of the rack112. The cartridge80is designed so that when actuated, the only exposed portion that moves is the rack head124. The sides of bar82that are pressed against tissue do not reciprocate. Since the bar82does not reciprocate, the possibility that the tissue could be damages such motion is eliminated. The fact that the cartridge bar82does not reciprocate also means that when the distal end of the cartridge80is pressed against tissue, this tissue is not exposed to back and forth motion as a result of the actuation of the cartridge80. Since this tissue is not exposed to this motion, it is not subjected to the stress of this motion that can tear or otherwise damage the tissue. Furthermore, when the cartridge80is inserted in the slot of the above-discussed resection guide and actuated, the cartridge bar82does not reciprocate. This eliminates the wear to that otherwise occurs as a result of the metal-against-metal reciprocal movement of the whole of the blade in the resection guide. The elimination of this wear results in a like elimination of the adverse effects of this wear. The webs104and feet106may extend through the void space in the bar82between the opposed inner surfaces of plates84. Webs104and feet106thus provide the bar82with stiffness. The feet106thus perform two functions, retaining the rack112in the bar82, and also providing structural strength to the bar82. It should likewise be understood that attachment52allows cartridge80to be used with a conventional saw30. This means that a facility that wants to use cartridge80is not required to purchase a saw30the only purpose of which is to be used with cartridge80. II. Second Embodiment FIGS.7-9illustrate the basic features of an alternative reciprocating saw130and an alternative blade cartridge180. Saw130has a tubular or pencil shaped body132. A motor, represented by a dashed rectangle134is disposed in the body132. A reciprocating shaft, represented by dashed rectangle140, extends forward of the motor. A transmission, not depicted, is located between the motor134and the reciprocating shaft140. The transmission converts the rotational movement of the motor rotor into motion that reciprocates the shaft back and forth. Not shown are the components that power the motor134. If the motor134is an electric motor, these components can include a control console or a battery that sources a drive current. If the motor134is a pneumatic motor. The drive components are the source of pressurized gas and the line over which the gas is supplied to the saw130. If the motor134is a hydraulically driven motor, these components are the source of pressurized liquid and the line over which the liquid is supplied to the saw130. Saw130, like saw30, may be designed to reciprocate a conventional reciprocal saw blade. A front end attachment150is removably attached to the distal end of the saw body132. The attachment150, together with the saw130and the blade cartridge180, may collectively comprise a second example saw system. Front end attachment150has a base152. Base152is the body of the attachment150. Base152is dimensioned to seat over and be removably attached to the distal end of the saw body132. The base152may be the first coupling feature by which the base is removably attached to the saw body132. One possible coupling structure is complementary threading on the saw130and on the attachment base152. An alternative coupling structure may be provided by one of the saw130or the attachment150having a snap lock that engages the other of the attachment or the saw. Still another structure for removably holding attachment150static to the saw body is to provide one or more compressible members that that provide a friction hold or a snap fit of the attachment150to the saw130. Forward of the base152, the front end attachment150has a nose154. The attachment150is formed so that as the nose154extends distally from the base152, the diameter of the nose154decreases. The attachment150is generally hollow. Not identified with reference numbers are the proximal and distal openings into the nose154. Attachment150is further formed so a slot156is formed in the nose154. Slot156, an example second coupling feature, is elongated in shape and has a major axis that is parallel to the longitudinal axis through the attachment150. The attachment150is formed so that the distal end of the slot156is spaced proximally from the distal end of the nose154. Forward of slot156, the attachment150may have two diametrically opposed slots. The opposed slots extend proximally from the distal end of the attachment nose154. One of the opposed slots is aligned with slot156. Cartridge180, as seen best inFIGS.10and11includes a static bar182in which a rack212is removably mounted. Bar182is formed from two plates184. The plates184are generally rectangular in shape. More specifically, each plate184has a top face190the edge of one of which is identified inFIG.11. Forward of the top face190, each plate184has a distally directed face186the edge of one of which is identified inFIG.11. Between the distally directed face186and the top face190there is a transition face188, the edge of one of which is identified inFIG.11. A plate184is formed so that, as the transition face186extends proximally from the distally directed face186tapers upwardly to the top face190. The plates184are further formed so a rib191protrudes upwardly from the top faces190. Each rib191extends forward a short distance, less than 1 cm, from the proximal end of the plate184with which the rib is integral. Each plate184is formed so as to have a slot192that is located entirely within the plate and that is located inward of the distally directed face190and a short distance above the bottom face185. Each slot192has an elongated section that extends parallel to the distally directed face186and an elongated section that extend parallel to the transition face188. Each plate184also has a slot194that extends distally forward from proximal end of the plate. The plates are formed so the distal end perimeters of slots194are semi-circular in shape. A spacer198is disposed between the plates184. Spacer198includes a beam202similar to the first described beam102. Thus beam202has sections that are flush with the distally directed faces186, the transition faces188and the top faces190of the plates184. The portion of the beam202that extends flush with the plate top faces190does not extend to the proximal end of the top faces190. Instead, spacer198is further formed to have leg201that extends proximally between the proximal portions of the plate top faces190. Leg201while integral with beam202has a top to bottom height less than that of beam. The spacer198is formed so that leg201extends proximally rearward beyond the plates184. A foot203, an example first holding feature, projects laterally upwardly from the section of the leg201located proximal to the plates184. A single web204extends perpendicularly from the beam202. A foot206is located at the end of web204. Web204and foot206have the same relationship to each other and beam202as web104and feet106due to beam102. When cartridge180is assembled, beam202, web204and foot206are held static between the plates184. Leg201and foot203are able to flex up and down. Rack212includes a base218. Base218is analogous in shape and function to base118of cartridge80. Thus base218has a single T-shaped opening, i.e., a guide slot220in which the cartridge web204and foot206seat. A leg217, also part of the rack212, extends proximally from the base218. Leg217extends into the space between the slots194formed in the cartridge bar182. Rack212is further formed to have a head224from which a set of linearly aligned teeth126extend. Head224extends outwardly from the section of the base218adjacent the bottom faces of the bar plates184. Again it should be understood that the head224and teeth126have a thickness greater than that of the rack leg217and base218and at least as great as the side to side thickness of the cartridge bar182. Thus, the components of cartridge180are designed to that the kerf cut by the teeth is of sufficient width to accommodate the cartridge bar182. An arbor228extends proximally from the leg217of the rack212. Arbor228is in the form of a solid cylindrical rod. Not identified with a reference number is a slot that extends proximally from the distal end of the arbor. This slot which extends across the arbor228, is dimensioned to receive leg217integral with rack212. The arbor228is braised or welded over the leg217. When cartridge180is assembled, the distal sections of the arbor that extend outwardly of the rack212seat in slots194formed in the blade bar. The components forming the cartridge180are dimensioned so that the arbor228can reciprocate in the bar slots194. The proximal end of the arbor228is formed with retention features, i.e., example second holding features230. The retention features are dimensioned to engage complementary retention features integral with the reciprocating shaft internal to the saw. These features when engaged, releasably hold the arbor228to the reciprocating shaft so the arbor reciprocates with the shaft. The retention features may include a set of notches230formed in the arbor. Saw130and cartridge180are readied for use by first fitting attachment150over the distal end of the saw body132. Cartridge180is then fitted to the saw. As part of this process, arbor228is coupled to the reciprocating shaft internal to the saw130. The leg201integral with spacer202is inserted into the attachment150until the associated foot203snaps into slot156formed in the attachment. The seating of foot203in the attachment slot156releasably holds the cartridge bar182to attachment150and, by extension, the saw130. As a result of the attachment of the cartridge180to the attachment, rib191and the portion of the spacer202sandwiched between the ribs seat in the opposed slot adjacent slot156. The ends of plates184opposed to ribs191seat in the second slot. The saw130with attached cartridge180is used in the same manner in which a conventional micro-style reciprocating saw is used. The actuation of the motor internal to the saw results in the back and forth movement of the reciprocating shaft. The reciprocation of the rod is, through the arbor228transferred to the rack212to cause the like movement of the rack. Owing to the dimensioning of the components, the seating of foot206in the rack opening220holds the rack for reciprocation in the cartridge bar182. The movement of the teeth126saws the tissue against which the head224is applied. During the cutting process, debris may enter the space between plates184. The debris are discharged through slots194. III. Third Embodiment FIGS.12and13depict a second alternative blade cartridge, cartridge240attached to the saw130and attachment150. The attachment150, together with the saw130and the blade cartridge240, may collectively comprise a third example saw system. Cartridge240, seen best inFIGS.14and15, includes a blade bar242. The blade bar242is formed from two plates244, seen best inFIG.15. Plates244have a distal end that is generally in the shape of the distal end of plates184of cartridge180. Plates244differ from plates184in that plates244have a top face249that extends proximally from the front face248, initially curves upwardly and then tapers upwardly. The tapered section of top face249subtends a length between 30 and 70% of the overall length of the plate244with which the face is integral. Plates244include proximally located slots245similar in shape and function to previously described slots194. Windows246are formed in plates244so as to be below and parallel to the tapered sections of plate top faces249 A spacer250, also part of the blade bar242, is located between the plates244. Spacer250has a foot252and a leg254similar to the foot203and leg201of cartridge180. A beam256extends distally from the leg254. Beam256is shaped to be flush with the top faces of the plates244between which the beam is disposed. Thus, the proximal section of beam256extends along a line that is parallel to the longitudinal axis of the cartridge. A distal section258of the beam256, extending distally from the proximal section, tapers downwardly. The distal end of beam256is formed to define a finger260that is angled relative to the adjacent tapered distal section258. Finger260is shaped to have an outer face, not identified, that is flush with the outer faces of the plate244. The beam256is further formed to have a second finger, finger262. Finger262projects proximally from the inner face of the beam section258, the face of the beam section disposed within the plates244. Finger262extends along a line that is parallel to or in registration with the longitudinal axis of the cartridge180. Also part of cartridge240is a rack270. Rack270includes a base274dimensioned to seat in and reciprocate in the void space between the plates244that is proximal to spacer250. The rack base274has a top edge, not identified that is tapered. The taper of the rack top edge corresponds to the taper of the beam distal section258. Rack base274is formed to have an elongated slot, i.e., a guide slot276. The slot276extends proximally from the tapered top edge of the rack base274. The rack270is formed so that the slot276is positioned to and dimensioned to receive the finger262internal to the cartridge bar242. A head280, also part of the rack270, extends from the bottom of the rack base274. Head280is the portion of the rack270that is located outwardly the bottom end of the blade bar242. A section of the head280is located forward of the distal end of the rack base274. The head280is formed to have teeth282. The teeth are shaped to cut the tissue against which the cartridge240is applied. The thickness of at least the teeth is greater than the thickness across the rack base274. More particularly, the teeth have a thickness so that the kerf cut by the teeth can accommodate the insertion of the cartridge bar into the kerf. At a minimum, the teeth282, if not the whole of the head280, has a thickness at least equal to the side-to-side thickness between the outer faces of plates244. Cartridge240includes the previously described arbor. Arbor228is welded or otherwise secured to the proximal portion of the rack base274. Cartridge240is fitted to the saw130using the same technique employed to fit cartridge180to the saw. The seating of foot252in the slot156releasably holds the cartridge to the saw130. Cartridge240is used in the manner in which cartridge130is employed. The seating of finger262in rack slot276holds the rack to the bar242. Cartridge240has a distal section with a relative short top to bottom height. A cartridge height, from the cutting edge of the teeth282to the top of the blade bar of the distalmost 1 cm portion of the cartridge, may be a maximum of 1.5 cm. Such a cartridge height may facilitate the positioning of the cartridge in confined spaces such as during intra oral cutting of the mandible in orthognathic procedures or when cutting the maxilla adjacent the infraorbital nerve. Cartridge240is thus well suited to cut tissue in locations where it may be difficult to position a cartridge of larger bottom-to-top height. During the cutting of tissue, the debris generated by the cutting process that enter the space between the plates240are discharged from the bar through windows246. IV. Alternative Embodiments Alternative versions of the claimed invention may have features different from what has been described. For example, the features of the disclosed systems and components may be combined as necessary. Likewise, the structural features may be different from what has been described. For example, the static member that extends into the slot may be a pin, inclusive of a pin-like structure. Further, such a pin or set of pins may be formed separately from the component that functions as the spacer between the bar plates. Further, the plural pins may seat in a single slot formed in the base of the rack. By extension, the slot in which this static component is disposed may be not open to the perimeter of the rack. This slot may be an elongated opening that is disposed entirely within the base of the rack. The component or components that hold the rack to the bar may be formed integrally with one or more of the plates that form the body of the bar. Thus, as a result of a stamping or machining process, one or more of the plates is formed with a raised member. This raised member is dimensioned to seat in the complementary elongated opening in the base of the rack. The static component may be formed by the selective molding or machining of the bar of the bar or rack with which the member is integral. It should likewise be appreciated that there is no requirement this static component have any curved surfaces. Thus, this component can be rectangular or square in shape. The slot may be a closed slot located completely in the rack. The complementary features of the bar and rack that hold the rack to the bar while allowing the rack to move linearly may be opposite what has been disclosed above, i.e., one or more static members may extend outwardly from one or both of the opposed sides of the base of the rack. The bar may be formed with one or more elongated openings, slots, to receive the static members. Thus, when the cartridge is assembled, the rack is disposed between the plates of the bar and the static member or members integral with the rack base are disposed in the one or more slots formed in the bar. The static members and slots are formed so that the rack can move linearly in the bar. Since the static member or members are seated in the bar, the member or members hold the rack in the bar. It should furthermore be understood that the static member, regardless of if this member is part of the bar or the rack, may be integrally formed with the component from which the member extends. The static member may be formed punching out a section of bar or rack with which the member is integral. The rack base may subtend a surface area that is more than 50% of the surface are of the bar in which the base is seated. The rack base may alternatively subtend an area less than this percentage of the surface of the bar. It may not be necessary to provide the bars with openings through which the debris generated in the cutting process can be discharged. The features integral with the rack to releasably hold the rack to the reciprocating shaft employed to reciprocate the rack may be different from what has been described. Likewise, the features integral with bar that facilitates holding the bar static to the associated attachment or saw to which the cartridge is coupled may vary from what has been described. The rack may be formed so that head and teeth project beyond the distal proximal end of the bar. Still another alternative blade cartridge292is now described with reference toFIGS.16and17. Cartridge292includes the previously described rack212and arbor228. Rack212is enclosed in a blade bar294. Blade bar294is formed to have two opposed plates296. Plates296are formed to have outer surfaces that, extending away from the side adjacent which the head224and teeth extend away from the bar, taper outwardly from the rack212. Spacer202separates the plates296so as to define the void space internal to the bar294in which the base218of the rack212is seated. The blade bar294is further formed so at the distal end to have a head298. Head298projects outwardly from the opposed outer surfaces of the plates296. The blade bar294is further formed so that this head is located distal to the distalmost location along the bar294from which teeth126extend when rack212reciprocates back and forth. Cartridge292can be used to cut bone when it is desirable limit the depth to which the cartridge is inserted by pressing a stop against the underside of the bone being cut. One such procedure is a procedure in which it is desirable to cut across the sternum without cutting the tissue below the sternum. In this type of procedure, the protruding head298of the cartridge bar performs the same function as the foot of a sternum guard. A benefit of cartridge292, sometimes called a sternum cartridge, is that this cartridge can be fitted to a saw30or attachment to which any of the above disclosed cartridges80,180or240may be is attached. This means it is possible to use a cartridge to cut through the sternum without going to the expense of providing a saw especially designed to hold a sternum guard. The tapered surfaces of the bar294serve to spread the sternum after the teeth126form the initial cut. Another procedure in which the cartridge292is useful is when the cartridge292is used to make a cut through the skull. In this type of procedure, the stop integral with the cartridge bar is employed to ensure the cartridge is not inserted to a depth that will result in the unintended cutting of tissue below the skull. From the above it should be understood that there is no requirement that the bar be constructed so the opposed sides are planar and parallel. It should be appreciated that when the bar has a tapered shape the head and teeth of the rack may not have a width thereacross equal to the maximum width of the bar. Instead, the head and teeth may be formed so that the kerf cut by the rack is at a minimum of sufficient depth to receive the adjacent section of the bar from which the rack head extends. Here the adjacent section of the bar is generally understood to be the first 3 to 10 mm portion of the bar that follows the head of the rack into the bone and, typically, no more than the first 8 mm portion of the bar that follows the head of rack into the bone. The wedge forming portion or portions of the bar that follow this bottom section are understood to, after the bone is cut, further separate the cut sections of bone apart from each other. It should further be understood that in alternative system, the saw may include features for both releasably holding the cartridge bar static to the body of the saw and releasably holding the rack to the reciprocating shaft. Thus, the features of the attachments that hold the bar static to the attachment may simply be incorporated into the saw. This saw is of use if the facility determines it is in the interest of the facility to simply have a saw available that, without an attachment, can be used to actuate the blade cartridge80. Accordingly, it is an object of the appended claims to cover all such variations and modifications that come within the true spirit and scope of this disclosure.

11857200

DETAILED DESCRIPTION Before turning to the figures, which illustrate the exemplary embodiments in detail, it should be understood that the application is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology is for the purpose of description only and should not be regarded as limiting. For example, several illustrations depict methods related to haptic control entry and exit when performing specific surgical procedures on a patient's knee. However, the embodiments of haptic control described herein may be applied to haptic control of a surgical tool during any type of surgical procedure on any part of a patient, including a patient's shoulder, arm, elbow, hands, hips, legs, feet, neck, face, etc. Exemplary Surgical System Referring toFIG.1, a surgical system100includes a navigation system10, a computer20, and a haptic device30. The navigation system tracks the patient's bone, as well as surgical tools utilized during the surgery, to allow the surgeon to visualize the bone and tools on a display24and to enable haptic control of a surgical tool36coupled to the haptic device30. The navigation system10may be any type of navigation system configured to track a patient's anatomy and surgical tools during a surgical procedure. For example, the navigation system10may include a non-mechanical tracking system, a mechanical tracking system, or any combination of non-mechanical and mechanical tracking systems. The navigation system10obtains a position and orientation (i.e. pose) of an object with respect to a coordinate frame of reference. As the object moves in the coordinate frame of reference, the navigation system tracks the pose of the object to detect movement of the object. In one embodiment, the navigation system10includes a non-mechanical tracking system as shown inFIG.1. The non-mechanical tracking system is an optical tracking system with a detection device12and a trackable element (e.g. navigation marker14) that is disposed on a tracked object and is detectable by the detection device12. In one embodiment, the detection device12includes a visible light-based detector, such as a MicronTracker (Claron Technology Inc., Toronto, CN), that detects a pattern (e.g., a checkerboard pattern) on a trackable element. In another embodiment, the detection device12includes a stereo camera pair sensitive to infrared radiation and positionable in an operating room where the surgical procedure will be performed. The trackable element is affixed to the tracked object in a secure and stable manner and includes an array of markers having a known geometric relationship to the tracked object. As is known, the trackable elements may be active (e.g., light emitting diodes or LEDs) or passive (e.g., reflective spheres, a checkerboard pattern, etc.) and have a unique geometry (e.g., a unique geometric arrangement of the markers) or, in the case of active, wired markers, a unique firing pattern. In operation, the detection device12detects positions of the trackable elements, and the surgical system100(e.g., the detection device12using embedded electronics) calculates a pose of the tracked object based on the trackable elements' positions, unique geometry, and known geometric relationship to the tracked object. The navigation system10includes a trackable element for each object the user desires to track, such as the navigation marker14located on the tibia2, navigation marker16located on the femur4, haptic device marker18(to track a global or gross position of the haptic device30), and an end effector marker19(to track a distal end of the haptic device30). Referring again toFIG.1, the surgical system100further includes a processing circuit, represented in the figures as a computer20. The processing circuit includes a processor and memory device. The processor can be implemented as a general purpose processor, an application specific integrated circuit (ASIC), one or more field programmable gate arrays (FPGAs), a group of processing components, or other suitable electronic processing components. The memory device (e.g., memory, memory unit, storage device, etc.) is one or more devices (e.g., RAM, ROM, Flash memory, hard disk storage, etc.) for storing data and/or computer code for completing or facilitating the various processes and functions described in the present application. The memory device may be or include volatile memory or non-volatile memory. The memory device may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described in the present application. According to an exemplary embodiment, the memory device is communicably connected to the processor via the processing circuit and includes computer code for executing (e.g., by the processing circuit and/or processor) one or more processes described herein. The computer20is configured to communicate with the navigation system10and the haptic device30. Furthermore, the computer20may receive information related to surgical procedures and perform various functions related to performance of surgical procedures. For example, the computer20may have software as necessary to perform functions related to image analysis, surgical planning, registration, navigation, image guidance, and haptic guidance. The haptic device30includes a base32, a robotic arm34, and a surgical tool36coupled to the robotic arm34. The surgical tool may be any surgical tool that can be coupled to the robotic arm34. For example, in the embodiment ofFIG.1, the surgical tool36is a spherical burr. The surgical tool36may also be a sagittal saw38, shown inFIG.2A, or sagittal saw40, shown inFIG.2B. The blade39of sagittal saw38is aligned parallel to tool axis42, while the blade39of sagittal saw40is aligned perpendicular to tool axis42. The surgeon can choose between a spherical burr, sagittal saw38, sagittal saw40, or any other type of surgical tool depending on the type of bone modification (e.g. hole, planar cut, curved edge, etc.) the surgeon desires to make. A surgeon interacts with haptic device30to perform surgical procedures on a patient. In general, haptic device30has two modes of operation. In free mode, the surgeon can substantially freely manipulate the pose of the surgical tool36. In haptic control mode, one or more haptic objects52are activated. The haptic object52can constrain the surgical tool36as described in various embodiments herein. Development of A Surgical Plan A surgical plan is created prior to a surgeon's performance of a surgical procedure. The surgical plan is developed utilizing a three-dimensional representation of a patient's anatomy, also referred to herein as a virtual bone model45(seeFIGS.3A-3D). A “virtual bone model” may include virtual representations of cartilage or other tissue in addition to bone. To obtain the virtual bone model45, the computer20receives images of the patient's anatomy on which the surgical procedure is to be performed. The patient's anatomy may be scanned using any known imaging technique, such as CT, Mill, or ultrasound. The scan data is then segmented to obtain the virtual bone model45. For example, prior to a surgical procedure on the knee, a three-dimensional representation of the femur4and tibia2is created. Alternatively, the virtual bone model45may be obtained by selecting a three-dimensional model from a database or library of bone models. In one embodiment, the user may use input device22to select an appropriate model. In another embodiment, the computer20may be programmed to select an appropriate model based on images or other information provided about the patient. The selected bone model(s) from the database can then be deformed based on specific patient characteristics, creating a virtual bone model45for use in surgical planning and implementation as described herein. The surgeon can create a surgical plan based on the virtual bone model45. The surgical plan may include the desired cuts, holes, or other modifications to a patient's bone44to be made by the surgeon using the surgical system100. The modifications may be planned based on the configuration of a component to be coupled to the bone during the surgery. For example, prior to performance of total knee arthroplasty, the surgical plan may include the planned modifications to bone illustrated inFIGS.3A-3D.FIGS.3A and3Billustrate a virtual bone model45of a femur4that includes planned modifications to the femur4, including anterior cut46, anterior chamfer cut92, distal cut84, posterior chamfer cut94, and posterior cut96.FIGS.3C and3Dillustrate a virtual bone model45of a tibia2that includes planned modifications to the tibia2, including tibial floor cut49, a wall cut51, and a peg cut53. The planned modifications to the femur4shown inFIGS.3A and3Bcorrespond to the virtual component66(FIG.6A), which represents a component to be coupled to the femur4. The surgical plan further includes one or more haptic objects that will assist the surgeon during implementation of the surgical plan by enabling constraint of the surgical tool36during the surgical procedure. A haptic object52may be formed in one, two, or three dimensions. For example, a haptic object can be a line (FIG.11A), a plane (FIG.6B), or a three-dimensional volume (FIG.13A). Haptic object52may be curved or have curved surfaces, and can be any shape. Haptic object52can be created to represent a variety of desired outcomes for movement of the surgical tool36during the surgical procedure. For example, a haptic object52in the form of a line may represent a trajectory of the surgical tool36. A planar haptic object52may represent a modification, such as a cut, to be created on the surface of a bone44. One or more of the boundaries of a three-dimensional haptic object may represent one or more modifications, such as cuts, to be created on the surface of a bone44. Furthermore, portions of a three-dimensional haptic object may correspond to portions of bone to be removed during the surgical procedure. Prior to performance of the surgical procedure, the patient's anatomy is registered to the virtual bone model45of the patient's anatomy by any known registration technique. One possible registration technique is point-based registration, as described in U.S. Pat. No. 8,010,180, titled “Haptic Guidance System and Method,” granted Aug. 30, 2011, and hereby incorporated by reference herein in its entirety. Alternatively, registration may be accomplished by 2D/3D registration utilizing a hand-held radiographic imaging device, as described in U.S. application Ser. No. 13/562,163, titled “Radiographic Imaging Device,” filed Jul. 30, 2012, and hereby incorporated by reference herein in its entirety. Registration of the patient's anatomy allows for accurate navigation and haptic control during the surgical procedure. When the patient's anatomy moves during the surgical procedure, the surgical system100moves the virtual bone model45in correspondence. The virtual bone model45therefore corresponds to, or is associated with, the patient's actual (i.e. physical) anatomy. Similarly, any haptic objects52created during surgical planning also move in correspondence with the patient's anatomy, and the haptic objects52correspond to locations in actual (i.e. physical) space. These locations in physical space are referred to as working boundaries. For example, a linear haptic object52corresponds to a linear working boundary in physical space, a planar haptic object52corresponds to a planar working boundary in physical space, and a three-dimensional haptic object52corresponds to a three-dimensional volume in physical space. The surgical system100further includes a virtual tool47(FIG.5A), which is a virtual representation of the surgical tool36. Tracking of the surgical tool36by the navigation system10during a surgical procedure allows the virtual tool47to move in correspondence with the surgical tool36. The virtual tool47includes one or more haptic interaction points (HIPs), which represent and are associated with locations on the physical surgical tool36. As described further below, relationships between HIPs and haptic objects52enable the surgical system100to constrain the surgical tool36. In an embodiment in which the surgical tool36is a spherical burr, an HIP60may represent the center of the spherical burr (FIG.11A). If the surgical tool36is an irregular shape, such as sagittal saws38or40(FIGS.2A and2B), the virtual representation of the sagittal saw may include numerous HIPs. Using multiple HIPs to generate haptic forces (e.g. positive force feedback or resistance to movement) on a surgical tool is described in U.S. application Ser. No. 13/339,369, titled “System and Method for Providing Substantially Stable Haptics,” filed Dec. 28, 2011, and hereby incorporated herein in its entirety. In one embodiment of the present invention, a virtual tool47representing a sagittal saw includes eleven HIPs. As used herein, references to an “HIP” are deemed to also include references to “one or more HIPs.” For example, HIP60can represent one or more HIPs, and any calculations or processes based on HIP60include calculations or processes based on multiple HIPs. During a surgical procedure, the surgical system100constrains the surgical tool36based on relationships between HIPs and haptic objects52. In general, the term “constrain,” as used herein, is used to describe a tendency to restrict movement. However, the form of constraint imposed on surgical tool36depends on the form of the relevant haptic object52. A haptic object52may be formed in any desirable shape or configuration. As noted above, three exemplary embodiments include a line, plane, or three-dimensional volume. In one embodiment, the surgical tool36is constrained because HIP60of surgical tool36is restricted to movement along a linear haptic object52. In another embodiment, the surgical tool36is constrained because planar haptic object52substantially prevents movement of HIP60outside of the plane and outside of the boundaries of planar haptic object52. The boundaries of the planar haptic object52act as a “fence” enclosing HIP60. If the haptic object52is a three-dimensional volume, the surgical tool36may be constrained by substantially preventing movement of HIP60outside of the volume enclosed by the walls of the three-dimensional haptic object52. Because of the relationship between the virtual environment (including the virtual bone model45and the virtual tool47) and the physical environment (including the patient's anatomy and the actual surgical tool36), constraints imposed on HIP60result in corresponding constraints on surgical tool36. Haptic Control During A Surgical Procedure At the start of a surgical procedure, the haptic device30(coupled to a surgical tool36) is typically in free mode. The surgeon is therefore able to move the surgical tool36towards bone44in preparation for creation of a planned modification, such as a cut or hole. Various embodiments presented herein may facilitate the switch of haptic device30from free mode to haptic control mode and from haptic control mode back to free mode, which may increase the efficiency and ease of use of surgical system100. One method for using a surgical system is illustrated inFIG.4. In step401, a surgical tool is provided. A virtual HIP is also provided, which is associated with the surgical tool (e.g., surgical tool36ofFIG.1) such that movement of the HIP corresponds to movement of the surgical tool36(step402). The surgical method further includes providing a virtual entry boundary and a virtual exit boundary (step403). As described further below, entry and exit boundaries are virtual boundaries created during surgical planning, and interactions between an HIP and the entry and exit boundaries may facilitate switching haptic device30between free mode and haptic control mode during a surgical procedure. In other words, interactions between the HIP and entry and exit boundaries facilitate entry into and exit from haptic control. In step404, a haptic object is activated. The activated haptic object can constrain the surgical tool after the haptic interaction point crosses the virtual entry boundary. In step405, the haptic object is deactivated after the HIP crosses the virtual exit boundary. Because the haptic object may be deactivated substantially simultaneously with the HIP crossing the virtual exit boundary, the term “after” can include deactivation that occurs at substantially the same time as the HIP crosses the virtual exit boundary. FIGS.5A-5Eillustrate the virtual environment during an embodiment of entry into and exit from haptic control. In this embodiment, the virtual bone model45represents a femur4, and virtual tool47represents a surgical tool36in the form of sagittal saw38(e.g. as shown inFIG.2A). A sagittal saw38may be useful for creating a variety of cuts during a total knee arthroplasty, such as cuts corresponding to planned anterior cut46, posterior cut96, and tibial floor cut49(FIGS.3A-3D). In the embodiment illustrated inFIGS.5A-5E, the planned modification is anterior cut46, which corresponds to the anterior surface68of a virtual implant component66(FIG.6A).FIG.3Bshows a perspective view of the planned anterior cut46on a virtual bone model45. The virtual environment depicted inFIG.5Aincludes a planar haptic object52. Planar haptic object52may also be an offset haptic object78(described below). Planar haptic object52may be any desired shape, such as the shape shown inFIG.6B.FIG.6Billustrates haptic object52, a blade of virtual tool47, and a virtual implant component66all superimposed on each other to aid in understanding the relationship between the various components of the surgical plan. In this embodiment, haptic object52represents a cut to be created on femur4. Haptic object52is therefore shown inFIGS.6A and6Baligned with anterior surface68of the virtual implant component66. The blade of virtual tool47is shown during haptic control mode, when haptic object52is activated and the blade is confined to the plane of haptic object52. Referring again toFIG.5A, entry boundary50is a virtual boundary created during development of the surgical plan. Interactions between HIP60and the entry boundary50trigger the haptic device30to switch from free mode to “automatic alignment mode,” a stage of haptic control described more fully below. The entry boundary50represents a working boundary in the vicinity of the patient's anatomy, and is designed and positioned such that the surgeon is able to accurately guide the surgical tool36to the working boundary when the haptic device30is in free mode. The entry boundary50may, but does not necessarily, enclose a portion of a haptic object52. For example, inFIG.5A, entry boundary50encloses a portion of haptic object52. FIG.5Apresents a cross-section of the virtual environment. In this embodiment, entry boundary50is pill-shaped and encloses a three-dimensional volume. The pill-shaped entry boundary50has a cylindrical portion with a radius R (shown inFIG.7A) and two hemispherical ends also having radius R (not shown). A target line54forms the cylinder axis (perpendicular to the page inFIG.5A). The target line54passes through a target point55, which is the center of entry boundary50in the illustrated cross section. Entry boundary50can also be any other shape or configuration, such as a sphere, a cube, a plane, or a curved surface. In one embodiment, entry boundary50can be a “Pacman-shaped” entry boundary50a, as shown inFIG.16. The Pacman-shaped entry boundary is formed by cutting out a segment of a pill-shaped entry boundary, as described above, to form an entry boundary50ahaving the cross section shown inFIG.16. In this embodiment, the entry boundary50ais therefore a three-dimensional volume shaped as a pill with a removed segment, such that a cross section of the virtual entry boundary is sector-shaped (i.e., “Pacman-shaped”). Pacman-shaped entry boundary50aincludes two intersecting haptic walls52a. A target line54(perpendicular to the page inFIG.16) represents the intersection of haptic walls52a. Target point55is the center of target line54. Haptic walls52aare an embodiment of the haptic objects52described herein, and can therefore constrain movement of a surgical tool36by substantially preventing HIP60from crossing haptic walls52a. Haptic walls52allow the Pacman-shaped entry boundary50ato create a safe zone in front of the patient's bone. The Pacman-shaped entry boundary50acan be used as the entry boundary in any of the embodiments described herein to protect the patient's bone when a surgical tool is approaching the patient.FIG.16illustrates virtual tool47(which corresponds to surgical tool36) as it makes contact with haptic wall52a. The haptic wall52aprevents the virtual tool47(and thus the surgical tool36) from crossing haptic wall52aand approaching the patient's bone. At the beginning of a surgical procedure, the surgeon guides surgical tool36towards the working boundary represented by entry boundary50. Once the surgeon causes HIP60of the surgical tool36to cross entry boundary50, the surgical system100enters automatic alignment. Prior to or during automatic alignment, the surgical system100performs calculations to reposition and reorient surgical tool36. In one embodiment, the calculations include computing distance58(seeFIG.5B). If the surgical tool36is a spherical burr, distance58may represent the shortest distance line between a single HIP60and target line54(e.g. as shown inFIG.11B) or another reference object. When the surgical tool36is a sagittal saw38or40, the calculations to reposition and reorient surgical tool36may be based on the position of multiple HIPs relative to target line54or other reference object, although a distance58may still be calculated. After performing the necessary calculations, the surgical system100is able to automatically align the surgical tool36from the pose of virtual tool47shown inFIG.5Bto the pose of virtual tool47shown inFIG.5C. The haptic control embodiments described herein may (1) automatically modify the position of surgical tool36(i.e. reposition), (2) automatically modify the orientation of surgical tool36(i.e. reorient), or (3) both automatically reposition and reorient the surgical tool36. The phrase “automatic alignment” can refer to any of scenarios (1), (2), or (3), and is a general term for modifying either or both of the position and orientation of the surgical tool36. In the embodiment ofFIGS.5A-5E, for example, automatic alignment may alter both the position and the orientation of surgical tool36relative to a bone44. Repositioning is accomplished by moving HIP60such that HIP60lies within the plane of haptic object52. In one embodiment, HIP60is repositioned to lie on target line54. Reorienting the surgical tool36may be accomplished by rotating the virtual tool47such that the virtual tool normal48is perpendicular to haptic object52(i.e. tool normal48is parallel to the haptic object normal62), as shown inFIG.5C. When the virtual tool47represents sagittal saw38, aligning the virtual tool normal48perpendicular to haptic object52causes the blade39of sagittal saw38to be accurately oriented relative to the bone44. However, if the cutting portion of surgical tool36is symmetrical, such as when surgical tool36is a spherical burr, it may not be necessary to reorient the surgical tool36during automatic alignment. Rather, surgical tool36might only be repositioned to bring HIP60within the plane of haptic object52. After automatic alignment is complete, surgical tool36is in place to perform a bone modification according to the preoperative surgical plan. The surgical system100may include a safety mechanism to provide the surgeon with control during automatic alignment. The safety mechanism can be designed to require certain actions (or continuation of an action) by a user for completion of automatic alignment. In one embodiment, the surgical system100produces an audible noise or other alert when HIP60crosses entry boundary50. The surgical system100is then able to initiate automatic alignment. However, before an automatic alignment occurs, the surgeon must act by depressing a trigger or performing another action. If the trigger is released during automatic alignment, the surgical system100may stop any automatic movement of haptic device30or cause haptic device30to enter free mode. In another embodiment, haptic device30includes a sensor to sense when the surgeon's hand is present. If the surgeon removes his or her hand from the sensor during automatic alignment, the surgical system100may stop any automatic movement of haptic device30or cause haptic device30to enter free mode. The surgeon acts to ensure completion of automatic alignment by continuing to keep his or her hand on the sensor. These embodiments of a safety mechanism allow the surgeon to decide whether and when to enable automatic alignment, and further allows the surgeon to stop automatic alignment if another object (e.g. tissue, an instrument) is in the way of surgical tool36during automatic alignment. Entry boundary50aofFIG.16is particularly beneficial if the above-described safety mechanisms are being utilized. As one illustration, the surgeon begins the haptic control processes described herein by guiding surgical tool36towards the patient until the surgical tool36penetrates an entry boundary. The surgical system100then alerts the surgeon that the system is ready to begin automatic alignment. However, the surgeon may not immediately depress a trigger or perform some other action to enable the system to initiate the automatic alignment mode. During this delay, the surgical tool36remains in free mode, and the surgeon may continue to guide the tool towards the patient. Accordingly, entry boundary50ashown inFIG.16includes haptic walls52a. These walls52aprevent the surgeon from continuing to guide the surgical tool36(represented by virtual tool47) towards the patient prior to enabling automatic alignment (e.g., via depressing a trigger or placing a hand on a sensor). The haptic walls52atherefore serve as a safety mechanism to protect the patient prior to the surgical tool36being appropriately positioned and oriented to perform the planned bone modifications. Referring toFIG.5C, automatic alignment is complete and the pose of surgical tool36has been correctly modified, and the haptic device30remains in haptic control mode. Haptic control mode, in general, can be characterized by the activation of a haptic object52and the imposition of a constraint on the movement of a surgical tool36by the haptic object52. Automatic alignment can therefore be a form of haptic control because haptic object52is activated, and surgical tool36is constrained to specific movements to realign surgical tool36based on haptic object52. During the stage of haptic control shown inFIG.5C, haptic object52is activated and HIP60is constrained within the plane defined by haptic object52. The surgeon can therefore move surgical tool36within the planar working boundary corresponding to haptic object52, but is constrained (e.g., prevented) from moving the surgical tool36outside of the planar working boundary. The surgeon performs the planned cut during haptic control mode. As the surgeon is cutting, the virtual tool47can move in the x-direction from the position illustrated inFIG.5Cto the position illustrated inFIG.5D. The virtual tool47may also move back and forth in the z-direction in correspondence with movement of surgical tool36. However, planar haptic object52restricts HIP60(and thus surgical tool36) from movement in the y-direction.FIG.6Billustrates one embodiment of the shape of haptic object52, shown with virtual tool47ofFIG.5Csuperimposed on haptic object52. A surgeon can reposition sagittal saw38within the working boundary corresponding to haptic object52, but the surgical system100prevents sagittal saw38from crossing the outer bounds of the working boundary.FIG.6Ais a view of haptic object52aligned with anterior surface68of a virtual implant component66. As mentioned previously, the modifications to bone, and thus the haptic objects52, are typically planned to correspond to the configuration of a component to be coupled to the bone during the surgical procedure. During portions of haptic control mode, an exit boundary64is activated (seeFIGS.5C-5E). The exit boundary64, like the entry boundary50, is a virtual boundary created during development of the surgical plan. Interactions between HIP60and exit boundary64deactivate haptic object52and trigger the haptic device30to switch from haptic control mode back to free mode. The surgical system therefore remains in haptic control mode and maintains surgical tool36within the working boundary corresponding to haptic object52until HIP60crosses the exit boundary64. Once HIP60crosses the exit boundary64(e.g. by moving from the position shown inFIG.5Dto the position shown inFIG.5E) the haptic object52deactivates and haptic device30switches from haptic control mode to free mode. When haptic control is released, the surgical tool36is no longer bound within the confines of a working boundary, but can be manipulated freely by the surgeon. In one embodiment, the exit boundary64is planar, located a distance L from entry boundary50(seeFIG.7A), and has an exit normal59. During haptic control mode, the surgical system100continuously calculates the distance from HIP60to exit boundary64. Because exit normal59points away from the patient's anatomy, the distance from HIP60to the exit boundary64will typically be negative during performance of bone modifications (e.g. cutting, drilling). However, when the value of this distance becomes positive, haptic control is released by deactivation of haptic object52, and the haptic device30enters free mode. In other embodiments, the exit boundary64can be curved, three-dimensional, or any configuration or shape appropriate for interacting with HIP60to disengage haptic control during a surgical procedure. Simultaneously or shortly after the switch to free mode, exit boundary64is deactivated and entry boundary50is reactivated. The surgeon can then reenter haptic control mode by causing surgical tool36to approach the patient such that HIP60crosses entry boundary50. Thus, the surgeon can move back and forth between free mode and haptic control by manipulating surgical tool36. The entry boundary50and exit boundary64described in connection with the various embodiments herein provide advantages over prior art methods of haptic control. Some prior art embodiments employing haptic objects require a separate action by a user to activate and deactivate haptic objects and thus enter and exit haptic control. For example, to release an HIP from the confines of a haptic object, the user might have to press a button or perform a similar action to deactivate the haptic object. The action by the user deactivates the haptic object, which then allows the surgeon to freely manipulate the surgical tool. Use of an exit boundary as described herein eliminates the need for the surgeon to perform a separate deactivation step. Rather, the surgeon must only pull a surgical tool36away from the patient to automatically deactivate a haptic object52and exit haptic control. Embodiments of the present disclosure may therefore save time in the operating room. Furthermore, operation of a haptic device30may be more intuitive and user-friendly due to the surgeon being able to switch conveniently between free mode and haptic control mode. FIGS.7A and7Billustrate haptic object52and offset haptic object78. A surgical plan may include an adjustable offset haptic object78to take into account characteristics of the surgical tool36. Use of offset haptic object78during haptic control mode of the haptic device30may provide additional accuracy during the surgical procedure by accounting for the dimensions of the surgical tool36. Thus, if the surgical tool36is a spherical burr, the offset haptic object78may be translated from haptic object52such that distance80(FIG.7B) is equivalent to the radius of the spherical burr. When offset haptic object78is activated, the surgical system100constrains HIP60of the spherical burr within the bounds of planar offset haptic object78, rather than constraining the HIP60of the spherical burr within the bounds of planar haptic object52. When constrained by the offset haptic object78, the edge of the spherical burr aligns with planned anterior cut46. Similarly, if the surgical tool36is a sagittal saw38, distance80may be equivalent to half the thickness t of blade39.FIG.7Billustrates virtual tool47. In this embodiment, virtual tool47is the sagittal saw38ofFIG.2Aand includes a virtual blade82. The virtual blade82has a thickness t equivalent to the thickness of blade39. When HIP60of virtual tool47is constrained to offset haptic object78, the bottom edge of virtual blade82will align with planned anterior cut46. The actual cut created by the sagittal saw38during surgery will then more closely correspond to the planned anterior cut46than if HIP60were constrained to haptic object52ofFIG.7B. In various embodiments, the surgical system100utilizes factors related to implementation of the surgical plan when calculating the parameters of adjustable offset haptic object78. One factor may be the vibrations of the surgical tool36during surgery, which can cause a discrepancy between the actual dimensions of a surgical tool36and the effective dimensions of the surgical tool36. For example, a spherical burr with a radius of 3 mm may remove bone as though its radius were 4 mm. The burr therefore has an effective radius of 4 mm. Similarly, due to vibrations, a blade39having a thickness of 2 mm may create a slot in bone having a thickness of 2.5 mm. The blade39therefore has an effective thickness of 2.5 mm. The offset haptic object78is created to take into account the effect of vibrations or other factors on surgical tool36to increase the accuracy of the actual bone modification created during surgery. The offset haptic object78may be adjustable. Adjustability is advantageous because it allows a user to modify the offset haptic object78without having to redesign the original haptic object52. The surgical system100may be programmed to allow easy adjustment by the user as new information is gathered prior to or during the surgical procedure. If the surgical plan includes offset haptic object78, additional elements of the surgical plan may be similarly adjusted to an offset position from their originally planned positions. For example, the surgical system100may be programmed to translate entry boundary50and exit boundary64in the y-direction by the same distance as the offset haptic object78is translated from the haptic object52. Similarly, target line54and target point55may also be offset from their initially planned position. It is to be understood that the “haptic object52” referred to by many of the embodiments described herein may technically be an “offset haptic object” with respect to the original haptic object of the relevant surgical plan. FIGS.8A-8Eillustrate the virtual environment during another embodiment of entry and exit from haptic control. In this embodiment, the virtual bone model45represents a femur4. Virtual tool47represents a surgical tool36in the form of a sagittal saw40(e.g. as shown inFIG.2B). A sagittal saw40may be useful for performing a variety of cuts during a total knee arthroplasty, such as cuts corresponding to planned distal cut84and anterior chamfer cut92. In the embodiment ofFIGS.8A-8E, the planned modification is a planned distal cut84, which corresponds to distal surface72of a virtual implant component66(FIG.9A). A perspective view of planned distal cut84is shown inFIG.3B. In this embodiment, as in the embodiment ofFIGS.5A-5E, haptic object52represents a cut to be created on femur4. Haptic object52may be any shape developed during surgical planning, such as the shape shown inFIG.9B. Referring again toFIGS.8A-8E, entry into and exit into haptic control takes place similarly as in the embodiment ofFIGS.5A-5E, differing primarily in the automatic alignment and resulting orientation of surgical tool36. Any applicable features disclosed in connection to the embodiment ofFIGS.5A-5Emay also be present in the embodiment ofFIG.8A-8E. InFIG.8A, the haptic device30is in free mode and entry boundary50is activated. As the surgeon brings the surgical tool36towards the patient's anatomy, the virtual tool47correspondingly approaches entry boundary50. Once HIP60has crossed entry boundary50, the surgical system100enters automatic alignment, during which the surgical system100performs the necessary calculations and then modifies the position and orientation of surgical tool36(e.g. fromFIG.8BtoFIG.8C). The position is modified to bring HIP60to the target line54, and the orientation is modified to bring tool axis42perpendicular to haptic object52. Because the blade39of sagittal saw40(FIG.2B) is perpendicular to the tool axis42, aligning the tool axis42perpendicular to the haptic object52causes the blade to lie in the x-y plane during the surgical procedure. Orientation of the tool axis42in this embodiment contrasts to the embodiment ofFIGS.5A-5E, in which the tool axis42is oriented parallel to haptic object52during cutting (e.g.,FIG.5C). The surgical plan may be developed such that the surgical system100will orient the surgical tool36in any desired direction relative to haptic object52. The desired orientation may depend on the type of surgical tool. For example, if the surgical tool36is a sagittal saw, the surgical system100may orient the surgical tool36differently depending on the type of sagittal saw (e.g. sagittal saw38or sagittal saw40) or the type of cut to be created. Furthermore, in some embodiments, the tool is repositioned but not reoriented during automatic alignment. For example, if the surgical tool36is a spherical burr, the surgical system100may not need to modify the orientation of the surgical tool36to obtain the desired bone modification. Once the surgical tool36has been automatically aligned as shown inFIG.8C, HIP60is constrained within the plane defined by haptic object52. Entry into this stage of haptic control can trigger activation of exit boundary64. The surgeon performs the cut by manipulating the surgical tool36within the planar working boundary corresponding to haptic object52in the x-direction and the z-direction.FIGS.8C and8Dillustrate a change in position during cutting along the x-direction. When the surgeon moves the surgical tool36from the position shown inFIG.8Dto the position shown inFIG.8E, HIP60crosses exit boundary64. The interaction between HIP60and exit boundary64deactivates haptic object52, releasing haptic control of surgical tool36and causing haptic device30to once again enter free mode. Upon crossing the exit boundary64or shortly thereafter, exit boundary64deactivates and entry boundary50reactivates. The surgeon can then reenter automatic alignment and haptic control during performance of bone modifications by manipulating surgical tool36such that HIP60crosses entry boundary50. FIG.10illustrates haptic object52and offset haptic object78in relation to planned distal cut84. As described in connection withFIGS.7A and7B, the adjustable offset haptic object78may be modified depending factors such as the dimensions of surgical tool36or other factors related to implementation of the surgical plan. The adjustment of offset haptic object78can lead to adjustment of other planned features of the virtual environment, such as entry boundary50, target line54, target point55, and exit boundary64. The surgical plans depicted inFIGS.7A-7B and10can be defined by various points and vectors. Normal origin point57lies on the original haptic object52and defines the origin of the haptic object normal62as well as the exit normal59. The haptic normal point61further defines the haptic object normal62, and may be located approximately 50 mm from the normal origin point57. The exit normal point63further defines the exit normal59, and may also be located approximately 50 mm from the normal origin point57. Thus, the haptic object normal62can be defined as the vector direction from the normal origin point57to the haptic normal point61, and the exit normal59can be defined as the vector direction from the normal origin point57to the exit normal point63. The target point55may lie on the offset haptic object78, and is offset from the normal origin point57in the direction of the haptic object normal62by a desired amount. As explained above, the desired amount may take into account the effective radius of a spherical burr or half of the effective thickness of a sagittal saw blade39. The target line54can be defined by target point55and the cross product vector of exit normal59and haptic object normal62, with endpoints on opposing edges of the offset haptic object78. FIGS.11A-11Eillustrate the virtual environment during another embodiment of entry and exit from haptic control. In this embodiment, the virtual bone model45represents a tibia2. Virtual tool47represents a surgical tool36in the form of a spherical burr, although the surgical tool36can be any tool capable of creating planned hole88. The planned modification is a hole88to receive the peg of a tibial component. The spherical burr can also be used to create holes for receiving pegs of femoral, patellofemoral, or any other type of implant component. InFIGS.11A-11E, a virtual tibial component90is superimposed on the bone model45to more clearly illustrate the planned bone modifications. In this embodiment, haptic object52is a line. The placement of linear haptic object52may be planned based on the dimensions or effective dimensions of surgical tool36, such as the radius TR of a spherical burr (FIG.12). For example, a space equivalent to radius TR may be left between the end95of haptic object52and the bottom of peg tip point91, as illustrated inFIG.12. FIG.11Aillustrates the virtual environment when haptic device30is in free mode. At the start of a surgical procedure, the surgeon moves surgical device36(FIG.1) towards the patient until HIP60crosses entry boundary50(FIG.11B). In this embodiment, entry boundary50is a sphere having a radius R (FIG.12) and having a target point55at its center. Once HIP60crosses entry boundary50, the surgical system automatically aligns surgical tool36. In one embodiment, the surgical system100calculates the shortest distance from HIP60to target point55and then repositions HIP60onto target point55. The surgical system100may also reorient surgical tool36such that tool axis42is parallel to haptic object52(FIG.11C). HIP60is then constrained to movement along linear haptic object52, and the surgeon can move surgical tool36along a linear working boundary corresponding to haptic device52to create hole88(FIG.11D). As in previous embodiments, the exit boundary64is activated during portions of haptic control. When the surgeon desires to release haptic control, the surgical tool36can be moved until HIP60crosses exit boundary64(FIG.11E). Haptic object52is then deactivated, releasing haptic control and causing the haptic device30to reenter free mode. As discussed in relation to other embodiments, the surgical system100may continuously calculate the distance between HIP60and exit boundary64, releasing haptic control when this distance becomes positive. Also as described in connection with previous embodiments, entry boundary50can be reactivated after release of haptic control. The surgeon can then reenter haptic control by manipulating surgical tool36such that HIP60crosses entry boundary50. FIG.12illustrates additional features of a surgical plan having a linear haptic object52, such as the surgical plan ofFIGS.11A-11E. The peg axis is a line from peg tip point91, located on the tip of planned hole88, to target point55. Linear haptic object52may be a line on the peg axis having a first endpoint at end95and a second endpoint located past the target point55along the exit normal59. For example, the second endpoint of haptic object52may located 50 mm past the target point55in the direction of exit normal59. The exit boundary64may be planar, located a distance L from the entry boundary50, and have an exit normal59defined as the vector direction from the peg tip point91to the target point55. FIGS.13A-13Dillustrate another embodiment of entry into and exit from haptic control. In this embodiment, haptic object52is a three-dimensional volume. Virtual bone model45can represent any bone44, such as a femur4, and virtual tool47can represent any type of surgical tool36for performing any type of bone modifications. In the virtual environment ofFIG.13A, haptic device30is in free mode. To enter haptic control, the user manipulates surgical tool36towards the patient's anatomy. Virtual tool47, including HIP60, move in correspondence towards entry boundary50. In this embodiment, entry boundary50is a plane that includes target point55(not shown). If HIP60is within haptic object52and HIP60crosses entry boundary50, as shown inFIG.13B, haptic control is engaged. In haptic control mode, HIP60is prevented from exiting the confines of the three-dimensional volume defined by haptic object52. Further, engagement of haptic control triggers deactivation of entry boundary50and activation of exit boundary64(FIG.13C). The embodiment ofFIGS.13A-13Ddoes not include automatic alignment. In other words, neither the position nor the orientation of surgical tool36is modified during haptic control. Consequently, HIP60can be freely moved to any position within haptic object52, and the orientation of surgical tool36is not constrained by a haptic object. During haptic control, the surgeon can freely move surgical tool36within the working volume corresponding to haptic object52to perform the necessary bone modifications, such as cuts corresponding to planned distal cut84, planned posterior chamfer cut92, and planned posterior cut96.FIG.13Cillustrates virtual tool47as the surgeon is creating a cut corresponding to planned posterior cut96. During haptic control in the embodiment ofFIGS.13A-13D, as in previous embodiments, when HIP60crosses exit boundary64(FIG.13D), haptic control is released and the haptic device30enters free mode. In alternative embodiments, the virtual environment depicted inFIGS.13A-13Dincludes additional mechanisms to control the position of HIP60. For example, planar haptic objects along planned cuts84,94, and96could constrain HIP60to movement along these planar haptic objects. The virtual environment might also include mechanisms to control the orientation of virtual tool47(and therefore, of surgical tool36), such as additional planar or linear haptic objects on which HIP60can be constrained. FIG.14illustrates the surgical plan ofFIGS.13A-13D. Exit boundary64is parallel to entry boundary50and is located a distance L from entry boundary50in the direction of exit normal59. Exit normal59is the vector direction from target point55to exit normal point63.FIG.14further includes a prior art haptic object98. In a prior art method of haptic control, a user could not cause an HIP to exit haptic object98without performing a separate action to disengage haptic control, such as a pressing a button on input device22(FIG.1). In contrast to prior art haptic object98, the volumetric haptic object52extends farther from the planned cutting surface. Further, the surgical plan associated with haptic object52includes an entry boundary50and an exit boundary64. In the presently disclosed embodiments, when the surgeon pulls surgical tool36away from the patient and causes HIP60to cross exit boundary64, the surgical system100automatically deactivates haptic object52to release haptic control. The provision of an exit boundary64therefore allows the surgeon greater freedom to release haptic control during surgery. In addition, the interaction between activation and deactivation of the entry boundary50and exit boundary64described herein allows the surgeon to seamlessly and intuitively enter and exit haptic control by manipulating surgical tool36, without having to perform separate actions to trigger entry into and exit from haptic control. FIG.15illustrates a haptic restoration feature that may be employed in any of the haptic control embodiments described herein. The haptic restoration feature is applicable when haptic control is disengaged for a reason other than because HIP60has crossed the exit boundary. Disengagement of haptic control might occur for various reasons, one of which relates to a temporary inability of the navigation system10to detect the pose of one or more tracked objects. For example, some navigation systems require a clear path between a detection device12and the trackable elements, such as navigation markers14and16, haptic device marker18, and end effector marker19(FIG.1). If one of the trackable elements is temporarily blocked (i.e. occluded), the navigation system10may not be able to effectively determine the pose of one or more tracked objects. As a safety precaution, when a trackable element becomes occluded during a surgical procedure, the surgical system100may disengage haptic control of the surgical tool36. Haptic control may also be disengaged due to sudden movement of a tracked object. For example, the patient's leg or the robotic arm34may be bumped, and the navigation system10is unable to accurately track the suddenly-moved object. The surgical system will therefore disengage haptic control of the surgical tool36. Disengagement of haptic control causes the haptic device30to enter free mode. The haptic restoration feature can then be utilized to either reengage haptic control by reactivating haptic object52or to retain the haptic device30in free mode and require the surgeon to reenter entry boundary50. To determine whether to reengage haptic control or whether to retain the haptic device30in free mode, the surgical system100is programmed to evaluate whether various conditions are met after the occlusion, sudden movement, or other factor has caused disengagement of haptic control. In general, the conditions may relate to the position or orientation of a surgical tool36relative to the desired, constrained position or orientation of surgical tool36, and the conditions may depend on the type of surgical tool36and the configuration of haptic object52. Three possible conditions to evaluate may be the tool's orientation, vertical penetration in a haptic plane, and whether all HIPs are within the haptic boundaries. For example, the embodiment ofFIG.15includes a virtual blade82, which represents a sagittal saw and includes multiple HIPs (as indicated above, although only one HIP60is labeled, references to HIP60include references to multiple HIPs).FIG.15also includes a planar haptic object52. In this embodiment, the haptic restoration feature may include determining the orientation of virtual blade82relative to haptic object52by calculating the angle between tool normal48and haptic object normal62. Tool normal48and haptic object normal62are ideally parallel if the surgical tool36is being constrained during cutting to lie within the working boundary corresponding to planar haptic object52. One condition may be, for example, whether tool normal48and haptic object normal62are within two degrees of each other. The surgical system100can be programmed to conclude that if this condition is met, the orientation of surgical tool36remains substantially accurate even after the temporary occlusion of a trackable element or sudden movement of the patient or robotic arm. The surgical system100may also evaluate the position of HIP60relative to planar haptic object52(e.g., vertical penetration).FIG.15illustrates virtual boundaries102,104above and below haptic object52. Virtual boundaries102,104, can be planned to lie, for example, approximately 0.5 mm away from haptic object52. A second condition may be whether HIP60lies between these virtual boundaries102,104. As another example, a third condition may be whether each of the HIPs60of virtual blade82lie within the outer bounds of haptic object52. If each of the relevant conditions are met, the haptic restoration feature reactivates haptic object52, which reengages haptic control and allows the surgeon to continue cutting. However, if any of the conditions are not met, the haptic device30remains in free mode. The surgeon must then cause HIP60to cross back into an entry boundary50(not shown inFIG.15), as described in the various embodiments herein. Once HIP60crosses entry boundary50, haptic control can be reengaged. In the embodiment illustrated inFIG.15, haptic control after HIP60has crossed entry boundary50may include automatic alignment and subsequent constraint of HIP60on planar haptic object52. In other embodiments, such as the embodiment ofFIGS.13A-13D, haptic control after HIP60crosses entry boundary50may not include automatic alignment. The construction and arrangement of the systems and methods as shown in the various exemplary embodiments are illustrative only. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, use of materials, colors, orientations, etc.). For example, the position of elements may be reversed or otherwise varied and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of the present disclosure. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present disclosure. The present disclosure contemplates methods, systems and program products on any machine-readable media for accomplishing various operations. The embodiments of the present disclosure may be implemented using existing computer processors, or by a special purpose computer processor for an appropriate system, incorporated for this or another purpose, or by a hardwired system. Embodiments within the scope of the present disclosure include program products comprising machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media can be any available media that can be accessed by a general purpose or special purpose computer or other machine with a processor. By way of example, such machine-readable media can comprise RAM, ROM, EPROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage, other magnetic storage devices, solid state storage devices, or any other medium which can be used to carry or store desired program code in the form of machine-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer or other machine with a processor. When information is transferred or provided over a network or another communications connection (either hardwired, wireless, or a combination of hardwired or wireless) to a machine, the machine properly views the connection as a machine-readable medium. Thus, any such connection is properly termed a machine-readable medium. Combinations of the above are also included within the scope of machine-readable media. Machine-executable instructions include, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing machines to perform a certain function or group of functions. Although a specific order of method steps may be described, the order of the steps may differ from what is described. Also, two or more steps may be performed concurrently or with partial concurrence (e.g. deactivation of entry boundary50and activation of exit boundary64). Such variation will depend on the software and hardware systems chosen and on designer choice. All such variations are within the scope of the disclosure. Likewise, software implementations could be accomplished with standard programming techniques with rule based logic and other logic to accomplish any connection steps, processing steps, comparison steps, and decision steps.

11857201

DETAILED DESCRIPTION Before turning to the figures, which illustrate the exemplary embodiments in detail, it should be understood that the application is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology is for the purpose of description only and should not be regarded as limiting. For example, several illustrations depict methods related to haptic control entry and exit when performing specific surgical procedures on a patient's knee. However, the embodiments of haptic control described herein may be applied to haptic control of a surgical tool during any type of surgical procedure on any part of a patient, including a patient's shoulder, arm, elbow, hands, hips, legs, feet, neck, face, etc. Exemplary Surgical System Referring toFIG.1, a surgical system100includes a navigation system10, a computer20, and a haptic device30. The navigation system tracks the patient's bone, as well as surgical tools utilized during the surgery, to allow the surgeon to visualize the bone and tools on a display24and to enable haptic control of a surgical tool36coupled to the haptic device30. The navigation system10may be any type of navigation system configured to track a patient's anatomy and surgical tools during a surgical procedure. For example, the navigation system10may include a non-mechanical tracking system, a mechanical tracking system, or any combination of non-mechanical and mechanical tracking systems. The navigation system10obtains a position and orientation (i.e. pose) of an object with respect to a coordinate frame of reference. As the object moves in the coordinate frame of reference, the navigation system tracks the pose of the object to detect movement of the object. In one embodiment, the navigation system10includes a non-mechanical tracking system as shown inFIG.1. The non-mechanical tracking system is an optical tracking system with a detection device12and a trackable element (e.g. navigation marker14) that is disposed on a tracked object and is detectable by the detection device12. In one embodiment, the detection device12includes a visible light-based detector, such as a MicronTracker (Claron Technology Inc., Toronto, CN), that detects a pattern (e.g., a checkerboard pattern) on a trackable element. In another embodiment, the detection device12includes a stereo camera pair sensitive to infrared radiation and positionable in an operating room where the surgical procedure will be performed. The trackable element is affixed to the tracked object in a secure and stable manner and includes an array of markers having a known geometric relationship to the tracked object. As is known, the trackable elements may be active (e.g., light emitting diodes or LEDs) or passive (e.g., reflective spheres, a checkerboard pattern, etc.) and have a unique geometry (e.g., a unique geometric arrangement of the markers) or, in the case of active, wired markers, a unique firing pattern. In operation, the detection device12detects positions of the trackable elements, and the surgical system100(e.g., the detection device12using embedded electronics) calculates a pose of the tracked object based on the trackable elements' positions, unique geometry, and known geometric relationship to the tracked object. The navigation system10includes a trackable element for each object the user desires to track, such as the navigation marker14located on the tibia2, navigation marker16located on the femur4, haptic device marker18(to track a global or gross position of the haptic device30), and an end effector marker19(to track a distal end of the haptic device30). Referring again toFIG.1, the surgical system100further includes a processing circuit, represented in the figures as a computer20. The processing circuit includes a processor and memory device. The processor can be implemented as a general purpose processor, an application specific integrated circuit (ASIC), one or more field programmable gate arrays (FPGAs), a group of processing components, or other suitable electronic processing components. The memory device (e.g., memory, memory unit, storage device, etc.) is one or more devices (e.g., RAM, ROM, Flash memory, hard disk storage, etc.) for storing data and/or computer code for completing or facilitating the various processes and functions described in the present application. The memory device may be or include volatile memory or non-volatile memory. The memory device may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described in the present application. According to an exemplary embodiment, the memory device is communicably connected to the processor via the processing circuit and includes computer code for executing (e.g., by the processing circuit and/or processor) one or more processes described herein. The computer20is configured to communicate with the navigation system10and the haptic device30. Furthermore, the computer20may receive information related to surgical procedures and perform various functions related to performance of surgical procedures. For example, the computer20may have software as necessary to perform functions related to image analysis, surgical planning, registration, navigation, image guidance, and haptic guidance. The haptic device30includes a base32, a robotic arm34, and a surgical tool36coupled to the robotic arm34. The surgical tool may be any surgical tool that can be coupled to the robotic arm34. For example, in the embodiment ofFIG.1, the surgical tool36is a spherical burr. The surgical tool36may also be a sagittal saw38, shown inFIG.2A, or sagittal saw40, shown inFIG.2B. The blade39of sagittal saw38is aligned parallel to tool axis42, while the blade39of sagittal saw40is aligned perpendicular to tool axis42. The surgeon can choose between a spherical burr, sagittal saw38, sagittal saw40, or any other type of surgical tool depending on the type of bone modification (e.g. hole, planar cut, curved edge, etc.) the surgeon desires to make. A surgeon interacts with haptic device30to perform surgical procedures on a patient. In general, haptic device30has two modes of operation. In free mode, the surgeon can substantially freely manipulate the pose of the surgical tool36. In haptic control mode, one or more haptic objects52are activated. The haptic object52can constrain the surgical tool36as described in various embodiments herein. Development of A Surgical Plan A surgical plan is created prior to a surgeon's performance of a surgical procedure. The surgical plan is developed utilizing a three-dimensional representation of a patient's anatomy, also referred to herein as a virtual bone model45(seeFIGS.3A-3D). A “virtual bone model” may include virtual representations of cartilage or other tissue in addition to bone. To obtain the virtual bone model45, the computer20receives images of the patient's anatomy on which the surgical procedure is to be performed. The patient's anatomy may be scanned using any known imaging technique, such as CT, MRI, or ultrasound. The scan data is then segmented to obtain the virtual bone model45. For example, prior to a surgical procedure on the knee, a three-dimensional representation of the femur4and tibia2is created. Alternatively, the virtual bone model45may be obtained by selecting a three-dimensional model from a database or library of bone models. In one embodiment, the user may use input device22to select an appropriate model. In another embodiment, the computer20may be programmed to select an appropriate model based on images or other information provided about the patient. The selected bone model(s) from the database can then be deformed based on specific patient characteristics, creating a virtual bone model45for use in surgical planning and implementation as described herein. The surgeon can create a surgical plan based on the virtual bone model45. The surgical plan may include the desired cuts, holes, or other modifications to a patient's bone44to be made by the surgeon using the surgical system100. The modifications may be planned based on the configuration of a component to be coupled to the bone during the surgery. For example, prior to performance of total knee arthroplasty, the surgical plan may include the planned modifications to bone illustrated inFIGS.3A-3D.FIGS.3A and3Billustrate a virtual bone model45of a femur4that includes planned modifications to the femur4, including anterior cut46, anterior chamfer cut92, distal cut84, posterior chamfer cut94, and posterior cut96.FIGS.3C and3Dillustrate a virtual bone model45of a tibia2that includes planned modifications to the tibia2, including tibial floor cut49, a wall cut51, and a peg cut53. The planned modifications to the femur4shown inFIGS.3A and3Bcorrespond to the virtual component66(FIG.6A), which represents a component to be coupled to the femur4. The surgical plan further includes one or more haptic objects that will assist the surgeon during implementation of the surgical plan by enabling constraint of the surgical tool36during the surgical procedure. A haptic object52may be formed in one, two, or three dimensions. For example, a haptic object can be a line (FIG.11A), a plane (FIG.6B), or a three-dimensional volume (FIG.13A). Haptic object52may be curved or have curved surfaces, and can be any shape. Haptic object52can be created to represent a variety of desired outcomes for movement of the surgical tool36during the surgical procedure. For example, a haptic object52in the form of a line may represent a trajectory of the surgical tool36. A planar haptic object52may represent a modification, such as a cut, to be created on the surface of a bone44. One or more of the boundaries of a three-dimensional haptic object may represent one or more modifications, such as cuts, to be created on the surface of a bone44. Furthermore, portions of a three-dimensional haptic object may correspond to portions of bone to be removed during the surgical procedure. Prior to performance of the surgical procedure, the patient's anatomy is registered to the virtual bone model45of the patient's anatomy by any known registration technique. One possible registration technique is point-based registration, as described in U.S. Pat. No. 8,010,180, titled “Haptic Guidance System and Method,” granted Aug. 30, 2011, and hereby incorporated by reference herein in its entirety. Alternatively, registration may be accomplished by 2D/3D registration utilizing a hand-held radiographic imaging device, as described in U.S. application Ser. No. 13/562,163, titled “Radiographic Imaging Device,” filed Jul. 30, 2012, and hereby incorporated by reference herein in its entirety. Registration of the patient's anatomy allows for accurate navigation and haptic control during the surgical procedure. When the patient's anatomy moves during the surgical procedure, the surgical system100moves the virtual bone model45in correspondence. The virtual bone model45therefore corresponds to, or is associated with, the patient's actual (i.e. physical) anatomy. Similarly, any haptic objects52created during surgical planning also move in correspondence with the patient's anatomy, and the haptic objects52correspond to locations in actual (i.e. physical) space. These locations in physical space are referred to as working boundaries. For example, a linear haptic object52corresponds to a linear working boundary in physical space, a planar haptic object52corresponds to a planar working boundary in physical space, and a three-dimensional haptic object52corresponds to a three-dimensional volume in physical space. The surgical system100further includes a virtual tool47(FIG.5A), which is a virtual representation of the surgical tool36. Tracking of the surgical tool36by the navigation system10during a surgical procedure allows the virtual tool47to move in correspondence with the surgical tool36. The virtual tool47includes one or more haptic interaction points (HIPs), which represent and are associated with locations on the physical surgical tool36. As described further below, relationships between HIPs and haptic objects52enable the surgical system100to constrain the surgical tool36. In an embodiment in which the surgical tool36is a spherical burr, an HIP60may represent the center of the spherical burr (FIG.11A). If the surgical tool36is an irregular shape, such as sagittal saws38or40(FIGS.2A and2B), the virtual representation of the sagittal saw may include numerous HIPs. Using multiple HIPs to generate haptic forces (e.g. positive force feedback or resistance to movement) on a surgical tool is described in U.S. application Ser. No. 13/339,369, titled “System and Method for Providing Substantially Stable Haptics,” filed Dec. 28, 2011, and hereby incorporated herein in its entirety. In one embodiment of the present invention, a virtual tool47representing a sagittal saw includes eleven HIPs. As used herein, references to an “HIP” are deemed to also include references to “one or more HIPs.” For example, HIP60can represent one or more HIPs, and any calculations or processes based on HIP60include calculations or processes based on multiple HIPs. During a surgical procedure, the surgical system100constrains the surgical tool36based on relationships between HIPs and haptic objects52. In general, the term “constrain,” as used herein, is used to describe a tendency to restrict movement. However, the form of constraint imposed on surgical tool36depends on the form of the relevant haptic object52. A haptic object52may be formed in any desirable shape or configuration. As noted above, three exemplary embodiments include a line, plane, or three-dimensional volume. In one embodiment, the surgical tool36is constrained because HIP60of surgical tool36is restricted to movement along a linear haptic object52. In another embodiment, the surgical tool36is constrained because planar haptic object52substantially prevents movement of HIP60outside of the plane and outside of the boundaries of planar haptic object52. The boundaries of the planar haptic object52act as a “fence” enclosing HIP60. If the haptic object52is a three-dimensional volume, the surgical tool36may be constrained by substantially preventing movement of HIP60outside of the volume enclosed by the walls of the three-dimensional haptic object52. Because of the relationship between the virtual environment (including the virtual bone model45and the virtual tool47) and the physical environment (including the patient's anatomy and the actual surgical tool36), constraints imposed on HIP60result in corresponding constraints on surgical tool36. Haptic Control During A Surgical Procedure At the start of a surgical procedure, the haptic device30(coupled to a surgical tool36) is typically in free mode. The surgeon is therefore able to move the surgical tool36towards bone44in preparation for creation of a planned modification, such as a cut or hole. Various embodiments presented herein may facilitate the switch of haptic device30from free mode to haptic control mode and from haptic control mode back to free mode, which may increase the efficiency and ease of use of surgical system100. One method for using a surgical system is illustrated inFIG.4. In step401, a surgical tool is provided. A virtual HIP is also provided, which is associated with the surgical tool (e.g., surgical tool36ofFIG.1) such that movement of the HIP corresponds to movement of the surgical tool36(step402). The surgical method further includes providing a virtual entry boundary and a virtual exit boundary (step403). As described further below, entry and exit boundaries are virtual boundaries created during surgical planning, and interactions between an HIP and the entry and exit boundaries may facilitate switching haptic device30between free mode and haptic control mode during a surgical procedure. In other words, interactions between the HIP and entry and exit boundaries facilitate entry into and exit from haptic control. In step404, a haptic object is activated. The activated haptic object can constrain the surgical tool after the haptic interaction point crosses the virtual entry boundary. In step405, the haptic object is deactivated after the HIP crosses the virtual exit boundary. Because the haptic object may be deactivated substantially simultaneously with the HIP crossing the virtual exit boundary, the term “after” can include deactivation that occurs at substantially the same time as the HIP crosses the virtual exit boundary. FIGS.5A-5Eillustrate the virtual environment during an embodiment of entry into and exit from haptic control. In this embodiment, the virtual bone model45represents a femur4, and virtual tool47represents a surgical tool36in the form of sagittal saw38(e.g. as shown inFIG.2A). A sagittal saw38may be useful for creating a variety of cuts during a total knee arthroplasty, such as cuts corresponding to planned anterior cut46, posterior cut96, and tibial floor cut49(FIGS.3A-3D). In the embodiment illustrated inFIGS.5A-5E, the planned modification is anterior cut46, which corresponds to the anterior surface68of a virtual implant component66(FIG.6A).FIG.3Bshows a perspective view of the planned anterior cut46on a virtual bone model45. The virtual environment depicted inFIG.5Aincludes a planar haptic object52. Planar haptic object52may also be an offset haptic object78(described below). Planar haptic object52may be any desired shape, such as the shape shown inFIG.6B.FIG.6Billustrates haptic object52, a blade of virtual tool47, and a virtual implant component66all superimposed on each other to aid in understanding the relationship between the various components of the surgical plan. In this embodiment, haptic object52represents a cut to be created on femur4. Haptic object52is therefore shown inFIGS.6A and6Baligned with anterior surface68of the virtual implant component66. The blade of virtual tool47is shown during haptic control mode, when haptic object52is activated and the blade is confined to the plane of haptic object52. Referring again toFIG.5A, entry boundary50is a virtual boundary created during development of the surgical plan. Interactions between HIP60and the entry boundary50trigger the haptic device30to switch from free mode to “automatic alignment mode,” a stage of haptic control described more fully below. The entry boundary50represents a working boundary in the vicinity of the patient's anatomy, and is designed and positioned such that the surgeon is able to accurately guide the surgical tool36to the working boundary when the haptic device30is in free mode. The entry boundary50may, but does not necessarily, enclose a portion of a haptic object52. For example, inFIG.5A, entry boundary50encloses a portion of haptic object52. FIG.5Apresents a cross-section of the virtual environment. In this embodiment, entry boundary50is pill-shaped and encloses a three-dimensional volume. The pill-shaped entry boundary50has a cylindrical portion with a radius R (shown inFIG.7A) and two hemispherical ends also having radius R (not shown). A target line54forms the cylinder axis (perpendicular to the page inFIG.5A). The target line54passes through a target point55, which is the center of entry boundary50in the illustrated cross section. Entry boundary50can also be any other shape or configuration, such as a sphere, a cube, a plane, or a curved surface. In one embodiment, entry boundary50can be a “Pacman-shaped” entry boundary50a, as shown inFIG.16. The Pacman-shaped entry boundary is formed by cutting out a segment of a pill-shaped entry boundary, as described above, to form an entry boundary50ahaving the cross section shown inFIG.16. In this embodiment, the entry boundary50ais therefore a three-dimensional volume shaped as a pill with a removed segment, such that a cross section of the virtual entry boundary is sector-shaped (i.e., “Pacman-shaped”). Pacman-shaped entry boundary50aincludes two intersecting haptic walls52a. A target line54(perpendicular to the page inFIG.16) represents the intersection of haptic walls52a. Target point55is the center of target line54. Haptic walls52aare an embodiment of the haptic objects52described herein, and can therefore constrain movement of a surgical tool36by substantially preventing HIP60from crossing haptic walls52a. Haptic walls52allow the Pacman-shaped entry boundary50ato create a safe zone in front of the patient's bone. The Pacman-shaped entry boundary50acan be used as the entry boundary in any of the embodiments described herein to protect the patient's bone when a surgical tool is approaching the patient.FIG.16illustrates virtual tool47(which corresponds to surgical tool36) as it makes contact with haptic wall52a. The haptic wall52aprevents the virtual tool47(and thus the surgical tool36) from crossing haptic wall52aand approaching the patient's bone. At the beginning of a surgical procedure, the surgeon guides surgical tool36towards the working boundary represented by entry boundary50. Once the surgeon causes HIP60of the surgical tool36to cross entry boundary50, the surgical system100enters automatic alignment. Prior to or during automatic alignment, the surgical system100performs calculations to reposition and reorient surgical tool36. In one embodiment, the calculations include computing distance58(seeFIG.5B). If the surgical tool36is a spherical burr, distance58may represent the shortest distance line between a single HIP60and target line54(e.g. as shown inFIG.11B) or another reference object. When the surgical tool36is a sagittal saw38or40, the calculations to reposition and reorient surgical tool36may be based on the position of multiple HIPs relative to target line54or other reference object, although a distance58may still be calculated. After performing the necessary calculations, the surgical system100is able to automatically align the surgical tool36from the pose of virtual tool47shown inFIG.5Bto the pose of virtual tool47shown inFIG.5C. The haptic control embodiments described herein may (1) automatically modify the position of surgical tool36(i.e. reposition), (2) automatically modify the orientation of surgical tool36(i.e. reorient), or (3) both automatically reposition and reorient the surgical tool36. The phrase “automatic alignment” can refer to any of scenarios (1), (2), or (3), and is a general term for modifying either or both of the position and orientation of the surgical tool36. In the embodiment ofFIGS.5A-5E, for example, automatic alignment may alter both the position and the orientation of surgical tool36relative to a bone44. Repositioning is accomplished by moving HIP60such that HIP60lies within the plane of haptic object52. In one embodiment, HIP60is repositioned to lie on target line54. Reorienting the surgical tool36may be accomplished by rotating the virtual tool47such that the virtual tool normal48is perpendicular to haptic object52(i.e. tool normal48is parallel to the haptic object normal62), as shown inFIG.5C. When the virtual tool47represents sagittal saw38, aligning the virtual tool normal48perpendicular to haptic object52causes the blade39of sagittal saw38to be accurately oriented relative to the bone44. However, if the cutting portion of surgical tool36is symmetrical, such as when surgical tool36is a spherical burr, it may not be necessary to reorient the surgical tool36during automatic alignment. Rather, surgical tool36might only be repositioned to bring HIP60within the plane of haptic object52. After automatic alignment is complete, surgical tool36is in place to perform a bone modification according to the preoperative surgical plan. The surgical system100may include a safety mechanism to provide the surgeon with control during automatic alignment. The safety mechanism can be designed to require certain actions (or continuation of an action) by a user for completion of automatic alignment. In one embodiment, the surgical system100produces an audible noise or other alert when HIP60crosses entry boundary50. The surgical system100is then able to initiate automatic alignment. However, before an automatic alignment occurs, the surgeon must act by depressing a trigger or performing another action. If the trigger is released during automatic alignment, the surgical system100may stop any automatic movement of haptic device30or cause haptic device30to enter free mode. In another embodiment, haptic device30includes a sensor to sense when the surgeon's hand is present. If the surgeon removes his or her hand from the sensor during automatic alignment, the surgical system100may stop any automatic movement of haptic device30or cause haptic device30to enter free mode. The surgeon acts to ensure completion of automatic alignment by continuing to keep his or her hand on the sensor. These embodiments of a safety mechanism allow the surgeon to decide whether and when to enable automatic alignment, and further allows the surgeon to stop automatic alignment if another object (e.g. tissue, an instrument) is in the way of surgical tool36during automatic alignment. Entry boundary50aofFIG.16is particularly beneficial if the above-described safety mechanisms are being utilized. As one illustration, the surgeon begins the haptic control processes described herein by guiding surgical tool36towards the patient until the surgical tool36penetrates an entry boundary. The surgical system100then alerts the surgeon that the system is ready to begin automatic alignment. However, the surgeon may not immediately depress a trigger or perform some other action to enable the system to initiate the automatic alignment mode. During this delay, the surgical tool36remains in free mode, and the surgeon may continue to guide the tool towards the patient. Accordingly, entry boundary50ashown inFIG.16includes haptic walls52a. These walls52aprevent the surgeon from continuing to guide the surgical tool36(represented by virtual tool47) towards the patient prior to enabling automatic alignment (e.g., via depressing a trigger or placing a hand on a sensor). The haptic walls52atherefore serve as a safety mechanism to protect the patient prior to the surgical tool36being appropriately positioned and oriented to perform the planned bone modifications. Referring toFIG.5C, automatic alignment is complete and the pose of surgical tool36has been correctly modified, and the haptic device30remains in haptic control mode. Haptic control mode, in general, can be characterized by the activation of a haptic object52and the imposition of a constraint on the movement of a surgical tool36by the haptic object52. Automatic alignment can therefore be a form of haptic control because haptic object52is activated, and surgical tool36is constrained to specific movements to realign surgical tool36based on haptic object52. During the stage of haptic control shown inFIG.5C, haptic object52is activated and HIP60is constrained within the plane defined by haptic object52. The surgeon can therefore move surgical tool36within the planar working boundary corresponding to haptic object52, but is constrained (e.g., prevented) from moving the surgical tool36outside of the planar working boundary. The surgeon performs the planned cut during haptic control mode. As the surgeon is cutting, the virtual tool47can move in the x-direction from the position illustrated inFIG.5Cto the position illustrated inFIG.5D. The virtual tool47may also move back and forth in the z-direction in correspondence with movement of surgical tool36. However, planar haptic object52restricts HIP60(and thus surgical tool36) from movement in the y-direction.FIG.6Billustrates one embodiment of the shape of haptic object52, shown with virtual tool47ofFIG.5Csuperimposed on haptic object52. A surgeon can reposition sagittal saw38within the working boundary corresponding to haptic object52, but the surgical system100prevents sagittal saw38from crossing the outer bounds of the working boundary.FIG.6Ais a view of haptic object52aligned with anterior surface68of a virtual implant component66. As mentioned previously, the modifications to bone, and thus the haptic objects52, are typically planned to correspond to the configuration of a component to be coupled to the bone during the surgical procedure. During portions of haptic control mode, an exit boundary64is activated (seeFIGS.5C-5E). The exit boundary64, like the entry boundary50, is a virtual boundary created during development of the surgical plan. Interactions between HIP60and exit boundary64deactivate haptic object52and trigger the haptic device30to switch from haptic control mode back to free mode. The surgical system therefore remains in haptic control mode and maintains surgical tool36within the working boundary corresponding to haptic object52until HIP60crosses the exit boundary64. Once HIP60crosses the exit boundary64(e.g. by moving from the position shown inFIG.5Dto the position shown inFIG.5E) the haptic object52deactivates and haptic device30switches from haptic control mode to free mode. When haptic control is released, the surgical tool36is no longer bound within the confines of a working boundary, but can be manipulated freely by the surgeon. In one embodiment, the exit boundary64is planar, located a distance L from entry boundary50(seeFIG.7A), and has an exit normal59. During haptic control mode, the surgical system100continuously calculates the distance from HIP60to exit boundary64. Because exit normal59points away from the patient's anatomy, the distance from HIP60to the exit boundary64will typically be negative during performance of bone modifications (e.g. cutting, drilling). However, when the value of this distance becomes positive, haptic control is released by deactivation of haptic object52, and the haptic device30enters free mode. In other embodiments, the exit boundary64can be curved, three-dimensional, or any configuration or shape appropriate for interacting with HIP60to disengage haptic control during a surgical procedure. Simultaneously or shortly after the switch to free mode, exit boundary64is deactivated and entry boundary50is reactivated. The surgeon can then reenter haptic control mode by causing surgical tool36to approach the patient such that HIP60crosses entry boundary50. Thus, the surgeon can move back and forth between free mode and haptic control by manipulating surgical tool36. The entry boundary50and exit boundary64described in connection with the various embodiments herein provide advantages over prior art methods of haptic control. Some prior art embodiments employing haptic objects require a separate action by a user to activate and deactivate haptic objects and thus enter and exit haptic control. For example, to release an HIP from the confines of a haptic object, the user might have to press a button or perform a similar action to deactivate the haptic object. The action by the user deactivates the haptic object, which then allows the surgeon to freely manipulate the surgical tool. Use of an exit boundary as described herein eliminates the need for the surgeon to perform a separate deactivation step. Rather, the surgeon must only pull a surgical tool36away from the patient to automatically deactivate a haptic object52and exit haptic control. Embodiments of the present disclosure may therefore save time in the operating room. Furthermore, operation of a haptic device30may be more intuitive and user-friendly due to the surgeon being able to switch conveniently between free mode and haptic control mode. FIGS.7A and7Billustrate haptic object52and offset haptic object78. A surgical plan may include an adjustable offset haptic object78to take into account characteristics of the surgical tool36. Use of offset haptic object78during haptic control mode of the haptic device30may provide additional accuracy during the surgical procedure by accounting for the dimensions of the surgical tool36. Thus, if the surgical tool36is a spherical burr, the offset haptic object78may be translated from haptic object52such that distance80(FIG.7B) is equivalent to the radius of the spherical burr. When offset haptic object78is activated, the surgical system100constrains HIP60of the spherical burr within the bounds of planar offset haptic object78, rather than constraining the HIP60of the spherical burr within the bounds of planar haptic object52. When constrained by the offset haptic object78, the edge of the spherical burr aligns with planned anterior cut46. Similarly, if the surgical tool36is a sagittal saw38, distance80may be equivalent to half the thickness t of blade39.FIG.7Billustrates virtual tool47. In this embodiment, virtual tool47is the sagittal saw38ofFIG.2Aand includes a virtual blade82. The virtual blade82has a thickness t equivalent to the thickness of blade39. When HIP60of virtual tool47is constrained to offset haptic object78, the bottom edge of virtual blade82will align with planned anterior cut46. The actual cut created by the sagittal saw38during surgery will then more closely correspond to the planned anterior cut46than if HIP60were constrained to haptic object52ofFIG.7B. In various embodiments, the surgical system100utilizes factors related to implementation of the surgical plan when calculating the parameters of adjustable offset haptic object78. One factor may be the vibrations of the surgical tool36during surgery, which can cause a discrepancy between the actual dimensions of a surgical tool36and the effective dimensions of the surgical tool36. For example, a spherical burr with a radius of 3 mm may remove bone as though its radius were 4 mm. The burr therefore has an effective radius of 4 mm. Similarly, due to vibrations, a blade39having a thickness of 2 mm may create a slot in bone having a thickness of 2.5 mm. The blade39therefore has an effective thickness of 2.5 mm. The offset haptic object78is created to take into account the effect of vibrations or other factors on surgical tool36to increase the accuracy of the actual bone modification created during surgery. The offset haptic object78may be adjustable. Adjustability is advantageous because it allows a user to modify the offset haptic object78without having to redesign the original haptic object52. The surgical system100may be programmed to allow easy adjustment by the user as new information is gathered prior to or during the surgical procedure. If the surgical plan includes offset haptic object78, additional elements of the surgical plan may be similarly adjusted to an offset position from their originally planned positions. For example, the surgical system100may be programmed to translate entry boundary50and exit boundary64in the y-direction by the same distance as the offset haptic object78is translated from the haptic object52. Similarly, target line54and target point55may also be offset from their initially planned position. It is to be understood that the “haptic object52” referred to by many of the embodiments described herein may technically be an “offset haptic object” with respect to the original haptic object of the relevant surgical plan. FIGS.8A-8Eillustrate the virtual environment during another embodiment of entry and exit from haptic control. In this embodiment, the virtual bone model45represents a femur4. Virtual tool47represents a surgical tool36in the form of a sagittal saw40(e.g. as shown inFIG.2B). A sagittal saw40may be useful for performing a variety of cuts during a total knee arthroplasty, such as cuts corresponding to planned distal cut84and anterior chamfer cut92. In the embodiment ofFIGS.8A-8E, the planned modification is a planned distal cut84, which corresponds to distal surface72of a virtual implant component66(FIG.9A). A perspective view of planned distal cut84is shown inFIG.3B. In this embodiment, as in the embodiment ofFIGS.5A-5E, haptic object52represents a cut to be created on femur4. Haptic object52may be any shape developed during surgical planning, such as the shape shown inFIG.9B. Referring again toFIGS.8A-8E, entry into and exit into haptic control takes place similarly as in the embodiment ofFIGS.5A-5E, differing primarily in the automatic alignment and resulting orientation of surgical tool36. Any applicable features disclosed in connection to the embodiment ofFIGS.5A-5Emay also be present in the embodiment ofFIG.8A-8E. InFIG.8A, the haptic device30is in free mode and entry boundary50is activated. As the surgeon brings the surgical tool36towards the patient's anatomy, the virtual tool47correspondingly approaches entry boundary50. Once HIP60has crossed entry boundary50, the surgical system100enters automatic alignment, during which the surgical system100performs the necessary calculations and then modifies the position and orientation of surgical tool36(e.g. fromFIG.8BtoFIG.8C). The position is modified to bring HIP60to the target line54, and the orientation is modified to bring tool axis42perpendicular to haptic object52. Because the blade39of sagittal saw40(FIG.2B) is perpendicular to the tool axis42, aligning the tool axis42perpendicular to the haptic object52causes the blade to lie in the x-y plane during the surgical procedure. Orientation of the tool axis42in this embodiment contrasts to the embodiment ofFIGS.5A-5E, in which the tool axis42is oriented parallel to haptic object52during cutting (e.g.,FIG.5C). The surgical plan may be developed such that the surgical system100will orient the surgical tool36in any desired direction relative to haptic object52. The desired orientation may depend on the type of surgical tool. For example, if the surgical tool36is a sagittal saw, the surgical system100may orient the surgical tool36differently depending on the type of sagittal saw (e.g. sagittal saw38or sagittal saw40) or the type of cut to be created. Furthermore, in some embodiments, the tool is repositioned but not reoriented during automatic alignment. For example, if the surgical tool36is a spherical burr, the surgical system100may not need to modify the orientation of the surgical tool36to obtain the desired bone modification. Once the surgical tool36has been automatically aligned as shown inFIG.8C, HIP60is constrained within the plane defined by haptic object52. Entry into this stage of haptic control can trigger activation of exit boundary64. The surgeon performs the cut by manipulating the surgical tool36within the planar working boundary corresponding to haptic object52in the x-direction and the z-direction.FIGS.8C and8Dillustrate a change in position during cutting along the x-direction. When the surgeon moves the surgical tool36from the position shown inFIG.8Dto the position shown inFIG.8E, HIP60crosses exit boundary64. The interaction between HIP60and exit boundary64deactivates haptic object52, releasing haptic control of surgical tool36and causing haptic device30to once again enter free mode. Upon crossing the exit boundary64or shortly thereafter, exit boundary64deactivates and entry boundary50reactivates. The surgeon can then reenter automatic alignment and haptic control during performance of bone modifications by manipulating surgical tool36such that HIP60crosses entry boundary50. FIG.10illustrates haptic object52and offset haptic object78in relation to planned distal cut84. As described in connection withFIGS.7A and7B, the adjustable offset haptic object78may be modified depending factors such as the dimensions of surgical tool36or other factors related to implementation of the surgical plan. The adjustment of offset haptic object78can lead to adjustment of other planned features of the virtual environment, such as entry boundary50, target line54, target point55, and exit boundary64. The surgical plans depicted inFIGS.7A-7B and10can be defined by various points and vectors. Normal origin point57lies on the original haptic object52and defines the origin of the haptic object normal62as well as the exit normal59. The haptic normal point61further defines the haptic object normal62, and may be located approximately 50 mm from the normal origin point57. The exit normal point63further defines the exit normal59, and may also be located approximately 50 mm from the normal origin point57. Thus, the haptic object normal62can be defined as the vector direction from the normal origin point57to the haptic normal point61, and the exit normal59can be defined as the vector direction from the normal origin point57to the exit normal point63. The target point55may lie on the offset haptic object78, and is offset from the normal origin point57in the direction of the haptic object normal62by a desired amount. As explained above, the desired amount may take into account the effective radius of a spherical burr or half of the effective thickness of a sagittal saw blade39. The target line54can be defined by target point55and the cross product vector of exit normal59and haptic object normal62, with endpoints on opposing edges of the offset haptic object78. FIGS.11A-11Eillustrate the virtual environment during another embodiment of entry and exit from haptic control. In this embodiment, the virtual bone model45represents a tibia2. Virtual tool47represents a surgical tool36in the form of a spherical burr, although the surgical tool36can be any tool capable of creating planned hole88. The planned modification is a hole88to receive the peg of a tibial component. The spherical burr can also be used to create holes for receiving pegs of femoral, patellofemoral, or any other type of implant component. InFIGS.11A-11E, a virtual tibial component90is superimposed on the bone model45to more clearly illustrate the planned bone modifications. In this embodiment, haptic object52is a line. The placement of linear haptic object52may be planned based on the dimensions or effective dimensions of surgical tool36, such as the radius TR of a spherical burr (FIG.12). For example, a space equivalent to radius TR may be left between the end95of haptic object52and the bottom of peg tip point91, as illustrated inFIG.12. FIG.11Aillustrates the virtual environment when haptic device30is in free mode. At the start of a surgical procedure, the surgeon moves surgical device36(FIG.1) towards the patient until HIP60crosses entry boundary50(FIG.11B). In this embodiment, entry boundary50is a sphere having a radius R (FIG.12) and having a target point55at its center. Once HIP60crosses entry boundary50, the surgical system automatically aligns surgical tool36. In one embodiment, the surgical system100calculates the shortest distance from HIP60to target point55and then repositions HIP60onto target point55. The surgical system100may also reorient surgical tool36such that tool axis42is parallel to haptic object52(FIG.11C). HIP60is then constrained to movement along linear haptic object52, and the surgeon can move surgical tool36along a linear working boundary corresponding to haptic device52to create hole88(FIG.11D). As in previous embodiments, the exit boundary64is activated during portions of haptic control. When the surgeon desires to release haptic control, the surgical tool36can be moved until HIP60crosses exit boundary64(FIG.11E). Haptic object52is then deactivated, releasing haptic control and causing the haptic device30to reenter free mode. As discussed in relation to other embodiments, the surgical system100may continuously calculate the distance between HIP60and exit boundary64, releasing haptic control when this distance becomes positive. Also as described in connection with previous embodiments, entry boundary50can be reactivated after release of haptic control. The surgeon can then reenter haptic control by manipulating surgical tool36such that HIP60crosses entry boundary50. FIG.12illustrates additional features of a surgical plan having a linear haptic object52, such as the surgical plan ofFIGS.11A-11E. The peg axis is a line from peg tip point91, located on the tip of planned hole88, to target point55. Linear haptic object52may be a line on the peg axis having a first endpoint at end95and a second endpoint located past the target point55along the exit normal59. For example, the second endpoint of haptic object52may located 50 mm past the target point55in the direction of exit normal59. The exit boundary64may be planar, located a distance L from the entry boundary50, and have an exit normal59defined as the vector direction from the peg tip point91to the target point55. FIGS.13A-13Dillustrate another embodiment of entry into and exit from haptic control. In this embodiment, haptic object52is a three-dimensional volume. Virtual bone model45can represent any bone44, such as a femur4, and virtual tool47can represent any type of surgical tool36for performing any type of bone modifications. In the virtual environment ofFIG.13A, haptic device30is in free mode. To enter haptic control, the user manipulates surgical tool36towards the patient's anatomy. Virtual tool47, including HIP60, move in correspondence towards entry boundary50. In this embodiment, entry boundary50is a plane that includes target point55(not shown). If HIP60is within haptic object52and HIP60crosses entry boundary50, as shown inFIG.13B, haptic control is engaged. In haptic control mode, HIP60is prevented from exiting the confines of the three-dimensional volume defined by haptic object52. Further, engagement of haptic control triggers deactivation of entry boundary50and activation of exit boundary64(FIG.13C). The embodiment ofFIGS.13A-13Ddoes not include automatic alignment. In other words, neither the position nor the orientation of surgical tool36is modified during haptic control. Consequently, HIP60can be freely moved to any position within haptic object52, and the orientation of surgical tool36is not constrained by a haptic object. During haptic control, the surgeon can freely move surgical tool36within the working volume corresponding to haptic object52to perform the necessary bone modifications, such as cuts corresponding to planned distal cut84, planned posterior chamfer cut92, and planned posterior cut96.FIG.13Cillustrates virtual tool47as the surgeon is creating a cut corresponding to planned posterior cut96. During haptic control in the embodiment ofFIGS.13A-13D, as in previous embodiments, when HIP60crosses exit boundary64(FIG.13D), haptic control is released and the haptic device30enters free mode. In alternative embodiments, the virtual environment depicted inFIGS.13A-13Dincludes additional mechanisms to control the position of HIP60. For example, planar haptic objects along planned cuts84,94, and96could constrain HIP60to movement along these planar haptic objects. The virtual environment might also include mechanisms to control the orientation of virtual tool47(and therefore, of surgical tool36), such as additional planar or linear haptic objects on which HIP60can be constrained. FIG.14illustrates the surgical plan ofFIGS.13A-13D. Exit boundary64is parallel to entry boundary50and is located a distance L from entry boundary50in the direction of exit normal59. Exit normal59is the vector direction from target point55to exit normal point63.FIG.14further includes a prior art haptic object98. In a prior art method of haptic control, a user could not cause an HIP to exit haptic object98without performing a separate action to disengage haptic control, such as a pressing a button on input device22(FIG.1). In contrast to prior art haptic object98, the volumetric haptic object52extends farther from the planned cutting surface. Further, the surgical plan associated with haptic object52includes an entry boundary50and an exit boundary64. In the presently disclosed embodiments, when the surgeon pulls surgical tool36away from the patient and causes HIP60to cross exit boundary64, the surgical system100automatically deactivates haptic object52to release haptic control. The provision of an exit boundary64therefore allows the surgeon greater freedom to release haptic control during surgery. In addition, the interaction between activation and deactivation of the entry boundary50and exit boundary64described herein allows the surgeon to seamlessly and intuitively enter and exit haptic control by manipulating surgical tool36, without having to perform separate actions to trigger entry into and exit from haptic control. FIG.15illustrates a haptic restoration feature that may be employed in any of the haptic control embodiments described herein. The haptic restoration feature is applicable when haptic control is disengaged for a reason other than because HIP60has crossed the exit boundary. Disengagement of haptic control might occur for various reasons, one of which relates to a temporary inability of the navigation system10to detect the pose of one or more tracked objects. For example, some navigation systems require a clear path between a detection device12and the trackable elements, such as navigation markers14and16, haptic device marker18, and end effector marker19(FIG.1). If one of the trackable elements is temporarily blocked (i.e. occluded), the navigation system10may not be able to effectively determine the pose of one or more tracked objects. As a safety precaution, when a trackable element becomes occluded during a surgical procedure, the surgical system100may disengage haptic control of the surgical tool36. Haptic control may also be disengaged due to sudden movement of a tracked object. For example, the patient's leg or the robotic arm34may be bumped, and the navigation system10is unable to accurately track the suddenly-moved object. The surgical system will therefore disengage haptic control of the surgical tool36. Disengagement of haptic control causes the haptic device30to enter free mode. The haptic restoration feature can then be utilized to either reengage haptic control by reactivating haptic object52or to retain the haptic device30in free mode and require the surgeon to reenter entry boundary50. To determine whether to reengage haptic control or whether to retain the haptic device30in free mode, the surgical system100is programmed to evaluate whether various conditions are met after the occlusion, sudden movement, or other factor has caused disengagement of haptic control. In general, the conditions may relate to the position or orientation of a surgical tool36relative to the desired, constrained position or orientation of surgical tool36, and the conditions may depend on the type of surgical tool36and the configuration of haptic object52. Three possible conditions to evaluate may be the tool's orientation, vertical penetration in a haptic plane, and whether all HIPs are within the haptic boundaries. For example, the embodiment ofFIG.15includes a virtual blade82, which represents a sagittal saw and includes multiple HIPs (as indicated above, although only one HIP60is labeled, references to HIP60include references to multiple HIPs).FIG.15also includes a planar haptic object52. In this embodiment, the haptic restoration feature may include determining the orientation of virtual blade82relative to haptic object52by calculating the angle between tool normal48and haptic object normal62. Tool normal48and haptic object normal62are ideally parallel if the surgical tool36is being constrained during cutting to lie within the working boundary corresponding to planar haptic object52. One condition may be, for example, whether tool normal48and haptic object normal62are within two degrees of each other. The surgical system100can be programmed to conclude that if this condition is met, the orientation of surgical tool36remains substantially accurate even after the temporary occlusion of a trackable element or sudden movement of the patient or robotic arm. The surgical system100may also evaluate the position of HIP60relative to planar haptic object52(e.g., vertical penetration).FIG.15illustrates virtual boundaries102,104above and below haptic object52. Virtual boundaries102,104, can be planned to lie, for example, approximately 0.5 mm away from haptic object52. A second condition may be whether HIP60lies between these virtual boundaries102,104. As another example, a third condition may be whether each of the HIPs60of virtual blade82lie within the outer bounds of haptic object52. If each of the relevant conditions are met, the haptic restoration feature reactivates haptic object52, which reengages haptic control and allows the surgeon to continue cutting. However, if any of the conditions are not met, the haptic device30remains in free mode. The surgeon must then cause HIP60to cross back into an entry boundary50(not shown inFIG.15), as described in the various embodiments herein. Once HIP60crosses entry boundary50, haptic control can be reengaged. In the embodiment illustrated inFIG.15, haptic control after HIP60has crossed entry boundary50may include automatic alignment and subsequent constraint of HIP60on planar haptic object52. In other embodiments, such as the embodiment ofFIGS.13A-13D, haptic control after HIP60crosses entry boundary50may not include automatic alignment. The construction and arrangement of the systems and methods as shown in the various exemplary embodiments are illustrative only. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, use of materials, colors, orientations, etc.). For example, the position of elements may be reversed or otherwise varied and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of the present disclosure. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present disclosure. The present disclosure contemplates methods, systems and program products on any machine-readable media for accomplishing various operations. The embodiments of the present disclosure may be implemented using existing computer processors, or by a special purpose computer processor for an appropriate system, incorporated for this or another purpose, or by a hardwired system. Embodiments within the scope of the present disclosure include program products comprising machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media can be any available media that can be accessed by a general purpose or special purpose computer or other machine with a processor. By way of example, such machine-readable media can comprise RAM, ROM, EPROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage, other magnetic storage devices, solid state storage devices, or any other medium which can be used to carry or store desired program code in the form of machine-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer or other machine with a processor. When information is transferred or provided over a network or another communications connection (either hardwired, wireless, or a combination of hardwired or wireless) to a machine, the machine properly views the connection as a machine-readable medium. Thus, any such connection is properly termed a machine-readable medium. Combinations of the above are also included within the scope of machine-readable media. Machine-executable instructions include, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing machines to perform a certain function or group of functions. Although a specific order of method steps may be described, the order of the steps may differ from what is described. Also, two or more steps may be performed concurrently or with partial concurrence (e.g. deactivation of entry boundary50and activation of exit boundary64). Such variation will depend on the software and hardware systems chosen and on designer choice. All such variations are within the scope of the disclosure. Likewise, software implementations could be accomplished with standard programming techniques with rule based logic and other logic to accomplish any connection steps, processing steps, comparison steps, and decision steps.

11857202

DETAILED DESCRIPTION The present application relates to devices, systems and methods that can be used in a knee replacement procedure, such as a total knee replacement procedure, as well as other types of knee replacement procedures. The present application discloses various assemblies that can be used together as a system for accomplishing portions of the knee replacement procedure, particularly those incorporating kinematic alignment of the tibia and femur. The system can include a tibial positioner device that can connect a distal femoral resection guide attached to a distally resected surface of a femur to a proximal tibial resection guide positioned along an anterior side of an unresected tibia. The tibial positioner device can releasably attach the femoral resection guide and the tibial resection guide such that a proximal tibial resection plane of the tibial resection guide is aligned parallel, or near parallel, to a posterior femoral resection plane of the femoral resection guide, with a desired distance therebetween. FIGS.1-3illustrate several aspects of a knee joint relevant for implant orientation.FIG.1illustrates various axes of the lower limb in the frontal plane. Axes can be defined for each segment of the lower limb. For example, femur10has anatomic axis32coinciding generally with an associated intramedullary canal. Femur10also has mechanical axis34, or load axis, running from the center of the femoral head to the center of the knee. Angle36between these two axes32,34in the frontal plane varies within the patient population but is on the order of 4° to 9°. The two axes32,34are approximately superimposed in the sagittal plane (FIG.2). Likewise, tibia12has mechanical axis38coinciding generally with an associated intramedullary canal. Mechanical axis38of tibia12runs from the center of the knee to the center of the ankle. Transverse axis, or joint line39, about which the knee flexes, is parallel to a line through the medial and lateral femoral condyles and parallel to the tibial plateau. Typically, the distal femur and proximal tibia are resected to be parallel to joint line39, and thus perpendicular to mechanical axes34,38as indicated at40and42. The intersection of femoral and tibial mechanical axes34,38may subtend a small angle relative to one another. However, the angle can be small such that axes34,38are approximately collinear and may be treated as collinear for most purposes. FIG.2illustrates the knee joint from the side or sagittal view and various bone cuts that may be made to align implant components. Distal femoral cut44is typically made perpendicular to femoral axes32,34in the sagittal plane. Proximal tibial resection46is typically cut to match the natural posterior slope, or rotation, of the proximal tibia relative to mechanical axes34,38. The amount of posterior to anterior slope50relative to reference line52perpendicular to mechanical axes34,38varies in the patient population but is on the order of 3°, 5° or 7°, or other values therebetween. In traditional mechanical alignment, this proximal tibial cut should be perpendicular to the mechanical axis, i.e., 0° of varus/valgus. Furthermore, in traditional mechanical alignment, this slope is reproduced via cut blocks with these corresponding slopes built-in. This slope can also be achieved by cutting the proximal tibia at 0° and using implants bearings with the correct slope built into the implant bearings. However, in kinematic alignment, the philosophy calls for more closely matching each patient's individual posterior slope, which may be between 0-7°. The distance between distal femoral cut44and proximal tibial cut46along mechanical axes34,38is the extension gap. Other cuts may be made depending on the components that are to be implanted. These include posterior femoral cut54, posterior femoral chamfer cut56, anterior femoral chamfer cut58and anterior femoral cut60. Patella62may also be cut to allow for replacement of the patellar articular surface. FIG.3depicts six aspects of component positioning relative to a coordinate system in which x-axis70corresponds approximately to joint line39, z-axis72corresponds approximately to mechanical axes34and38, and y-axis74is normal to the other two. Position along each of these axes is depicted by arrows. Position along the x-, y-, and z-axes determines medial/lateral (dx)76, anterior/posterior (dy)78, and proximal/distal (dz)80positioning of components respectively. Rotation about each of these axes is also depicted by arrows. Rotation about z-axis (rz)82corresponds anatomically to external rotation of the femoral component, rotation about x-axis (rx)84corresponds to extension plane rotation, and rotation about y-axis (ry)86corresponds to vaus/valgus rotation. Primary goals of kinematically aligned TKA are (1) positioning the femoral and tibial components of a knee prosthesis such that the angles and levels of the distal and posterior femoral and tibial joint lines are restored to the patient's natural joint line, (2) restoration of the patient's natural or constitutional alignment prior to the patient having developed osteoarthritis, and (3) restoration of the patient's natural soft tissue laxity and envelope. The kinematically aligned TKA can include a determination of the three kinematic axes illustrated inFIGS.4A-4C. FIGS.4A-4Cshow various views of knee prosthesis90implanted on a knee joint and illustrate the three kinematic axes of the knee joint in a kinematically aligned TKA. Knee prosthesis90can include femoral component92implanted on femur10and tibial component94implanted on tibia12. A polyethylene surface can be inserted between femur10and tibia12. A kinematically aligned knee includes three axes that describe functional axes of movement about which the knee flexes and rotates. Kinematic alignment considers three-dimensional alignment of the prosthetic femoral and tibial components with respect to the knee instead of two-dimensional alignment of the components with respect to the center of the femoral head and ankle as is done with mechanical alignment. In an example, a femoral component used in kinematic alignment can include symmetric, single-radius condyles on an articular surface. One aspect of kinematic alignment can be to restore normal knee function by aligning the distal and posterior femoral joint line of the femoral component according to the functional femoral transverse axes and joint line of the tibial component to those of the normal knee status. First kinematic axis96can be a transverse axis in femur10about which tibia12flexes and extends. First kinematic axis96can be determined by projecting the lateral and medial femoral condyles of femur10onto one another and fitting circles of equal radii over each other. First kinematic axis96passes through a center of the circles. Second kinematic axis97can be a second transverse axis, parallel to first kinematic axis96, about which a patella of the knee joint flexes and extends. Second kinematic axis97can be located anterior and proximal to first kinematic axis96. Third kinematic axis98is an axis perpendicular to first96and second97axes about which tibia12internally and externally rotates on femur10. The methods and devices of the present application facilitate alignment of tibial and femoral resections such that axes96,97and98align. For example, a posterior femoral resection can be aligned with a proximal tibial resection to facilitate alignment, such as parallel alignment, of first kinematic axis96and second kinematic axis97. FIG.5is a front view of tibial positioner device100according to an embodiment of the present disclosure coupled to femoral cutting guide102and tibial cutting guide104for attachment to femur10and tibia12of a knee joint. Femoral cutting guide102can be attached to femur10via pins16A and16B. Tibial cutting guide104can be attached to femoral cutting guide102via tibial positioner device100. Tibial positioner device100can comprise femoral coupling block108, tibial coupling block110, extension112, femoral coupling pins114A and114B, and tibial coupling pins116A and116B. Femoral cutting guide102can comprise a plurality of cutting slots, such as posterior cutting slot118A. Tibial cutting guide104can include various cutting slots, such as proximal cutting slot120A. Femoral cutting guide102and tibial cutting guide104can be used to perform resections on femur10and tibia12, respectively, for a total knee arthroplasty (TKA) procedure. Femoral cutting guide102and tibial cutting guide104can be used to perform TKA procedures with various alignments. For example, guides102and104can be used for mechanical, kinematic and measured alignment of femur10and tibia12. Tibial positioner device100can be used to position tibial cutting guide104relative to femoral cutting guide102to achieve a desired alignment therebetween. In particular, tibial positioner device100can be used to align tibial cutting guide104relative to femoral cutting guide102for kinematic alignment of femur10and tibia12. For example, tibial positioner device100, femoral cutting guide102and tibial cutting guide104can be configured to align proximal cutting slot120A parallel to posterior cutting slot118A, as can be desirable in a TKA procedure using kinematic alignment. FIG.6is an exploded view of tibial positioner device100, femoral cutting guide102and tibial cutting guide104ofFIG.5showing various components of the devices. As mentioned, tibial positioner device100can comprise femoral coupling block108, tibial coupling block110, extension112, femoral coupling pins114A and114B, and tibial coupling pins116A and116B. Femoral coupling block108can comprise sockets122A and122B for receiving pins114A and114B, respectively. Tibial coupling block110can comprise sockets124A and124B for receiving pins116A and116B, respectively. Extension112can comprise extension pins126A and126B. Femoral coupling block108can also include sockets128A and128B, and tibial coupling block110can include sockets130A and130B. Sockets128A and130A can receive extension pin126A, and sockets128B and130B can receive extension pin126B. Femoral cutting guide102can include posterior cutting slot118A, anterior cutting slot118B, posterior chamfer slot118C, anterior chamfer slot118D, center bore132, anchor pin bores134A and134B, and mounting bores136A and136B. Tibial cutting guide102can include proximal cutting slots120A, anchor pin bore groupings138A and138B, and mounting bores140A and140B. Pins114A and114B can be configured to couple to sockets122A and122B, respectively. In an example, pins114A and114B can be configured to be friction fit within sockets122A and122B. Pins114A and114B can also be configured to couple to mounting bores136A and136B, respectively. In an example, pins114A and114B can be configured to freely slide within sockets136A and136B. Pins116A and116B can be configured to couple to sockets124A and124B, respectively. In an example, pins116A and116B can be configured to be friction fit within sockets124A and124B. Pins116A and116B can also be configured to couple to mounting bores140A and140B, respectively. In an example, pins116A and116B can be configured to freely slide fit within sockets140A and140B. Pins126A and126B can be configured to couple to sockets128A and128B and sockets130A and130B, respectively. In an example, pins126A and126B can be configured to be friction fit within sockets128A,128B,130A and130B. However, as discussed below, extension112can have other configurations. Pins126A and126B can be configured to connect block108and block110in a superior-inferior direction. Posterior face144of femoral coupler block108can be configured to mate with femoral cutting guide102. For example, posterior face144can be flat and disposed in a plane perpendicular to the plane extending through the centers of sockets122A and122B. As such, a flat posterior face144can mate flush against a flat face of femoral cutting guide102and a surgeon can have a visual indication that femoral coupler block108is properly connected o femoral cutting guide102. Posterior face146of tibial coupler block110can be configured to mate with tibial cutting guide104. For example, posterior face146can be flat and disposed in a plane perpendicular to the plane extending through the centers of sockets124A and124B. As such, a flat posterior face146can mate flush against a flat face of tibial cutting guide104and a surgeon can have a visual indication that tibial coupler block110is properly connected o tibial cutting guide104. When tibial coupler block110and femoral coupler block108are attached, posterior face146can be offset from posterior face144in an anterior-posterior direction toward extension112, which can permit femoral cutting guide102to be positioned above tibia12and back against planar distal femoral surface186, while tibial cutting guide104is positioned anterior of the proximal end of tibia12, as shown below inFIG.14. Femoral cutting guide102can have posterior face147that is configured to mate with femur10. For example, posterior face147can be flat to mate flush against planar distal femoral surface186(FIG.11). Tibial cutting guide104can have posterior face148that is configured to mate with tibia12. For example, forward face148can be curved or arcuate to partially wrap around the curvature of the proximal portion of tibia12. FIG.7Ais a front view of the tibial positioner device100ofFIGS.5and6showing extension pins126A and126B connecting femoral coupler block108and tibial coupler block110.FIG.7Bis a side view of tibial positioner device100ofFIG.7Ashowing coupler pins114A and116A for insertion into femoral cutting guide102and tibial cutting guide104.FIGS.7A and7Bare discussed concurrently. In an example, extension112is configured to couple femoral coupler block108and tibial coupler block110in a desired manner suitable for aligning femoral cutting guide102and tibial cutting guide104for performing resections for kinematic alignment. Extension112can be configured in a variety of ways to either fixedly or adjustably connect block108and block110. In the illustrated embodiment ofFIGS.5-7B, extension112can comprise a pair of spaced apart pins, e.g., pins126A and126B. Use of two spaced apart pins can prevent relative rotation between femoral coupler block108and tibial coupler block110, as opposed to a single round pin. However, in other embodiments a single pin, post or beam can be used, such as a square post to prevent rotation. In yet other examples, femoral block108and tibial block110can be connected by C-shaped members or pins to attach to anterior surfaces of blocks108and110opposite posterior surfaces144and146. Additionally, in the illustrated embodiment ofFIGS.5-7A, pins126A and126B can comprise bodies of a fixed length to fixedly attach block108and block110to each. In an example, extension112is configured to position cutting slot120A a distance D away from pins114A and114B. In an embodiment, distance D can be approximately 19 mm. However, in other embodiments, pins126A and126B can be configured to be adjustable in length so that distance D can be adjusted by a surgeon. For example, as illustrated inFIG.7B, pin126A (and pin126B though not visible inFIG.7B) can be configured to have a telescoping construction where lower pin portion142A slides into upper pin portion142B. Pin portions142A and142B can be configured with a stop mechanism to incrementally arrest movement of pin portion142A within pin portion142B. For example, a detent mechanism can be used. In an example detent mechanism, upper pin portion142B can be outfitted with a spring-loaded ball bearing that is pushed toward an interior channel of upper pin portion142B, and lower pin portion142A can include a series of spaced apart dimples into which the ball bearing can be pushed. Extension112can additionally be provided with indicia, such as hash marks, numbering, a scale and the like to indicate the magnitude of distance D. Extension112can be used to balance the knee joint by positioning femoral cutting guide102(FIG.6) with respect to tibial cutting guide104. In an example for kinematic alignment, extension112aligns the plane of pins114A and114B with the plane of pins116A and116B so that cutting slot118A of femoral cutting guide102(FIG.6) is parallel to cutting slot120A of tibial cutting guide104so that the knee is balanced with zero degrees of rotation. FIGS.8-15illustrate various method steps that can be used in to perform a total knee arthroplasty procedure using tibial positioner device100. In various examples, tibial positioner device100can be used to perform total knee arthroplasty procedures wherein femoral and tibial prosthetic devices can be implanted for kinematic alignment. FIG.8is a perspective view of a knee joint with tibia12in flexion relative to femur10with drilling tool150used to produce intramedullary canal152within femur10. Femur10and tibia12can be positioned to produce angle154therebetween. In various embodiments, angle154can be approximately 900 for a total knee arthroplasty (TKA). Placing the knee joint in flexion facilitates access to medial condyle156M and lateral condyle156L of femur10and tibial plateau158on the proximal portion of tibia12. As such, distal and anterior cutting guides for femur10and proximal cutting guides for tibia12can be readily placed onto the knee joint. Drilling tool150can comprise any suitable tool for producing intramedullary canal152in femur10. For example, an electric or manual powered drill can be used to couple to and rotate drill bit160. Drill bit160can be rotated by drilling tool150to cut through cortical bone between condyles156M and156L to penetrate into cancellous bone located in the intramedullary cavity within femur10. Drilling tool150and drill bit160can be removed from intramedullary canal152such that intramedullary canal152can be used to attach other components or devices for the surgical procedure to femur10. FIG.9is a perspective view of valgus alignment guide162coupled to intramedullary rod164disposed within femur10ofFIG.8that can be used to install distal femoral cutting guide166. Intramedullary rod164can be attached to modular handle168. Valgus alignment guide162can be attached to intramedullary rod164, and intramedullary rod164can be inserted into intramedullary canal152. Valgus alignment guide162can be set to the desired valgus angle from approximately 0° to 9° in embodiments using locking knob170. Resection tower172can be attached to valgus alignment guide162for coupling to and positioning of distal femoral cutting guide166. Resection tower172can be adjusted to set the depth for the distal femoral resection to be performed with distal femoral cutting guide166. Valgus alignment guide162can then be pushed to engage flat plate174against condyles156M and156L. With distal femoral cutting guide166attached to rod176of resection tower172, engagement of flat plate174with femur10can position distal femoral cutting guide166to facilitate resection of the distal-most portions of condyles156M and156L. Distal femoral cutting guide166can be coupled to femur10using pins178A and178B. In an example, instruments and procedures for placing and attaching distal femoral cutting guide166are described in U.S. Pub. No. 2016/0030053 to Yager et al., which is assigned to Zimmer, Inc., the contents of which are hereby incorporated in their entirety by this reference.FIG.9illustrates one exemplary scenario, i.e., an example device and procedure, for resecting condyles156M and156L, but other scenarios can be used to resect condyles156M and156L. FIG.10is a perspective view of cutting blade180inserted into cutting slot182of distal femoral cutting guide166to resect distal portions of medial and lateral condyles156M and156L of femur10. A section, i.e., condyle section184ofFIG.11, of the distal end of femur10including the distal-most portions of condyles156M and156L can be removed from femur10to produce planar distal femoral surface186. FIG.11is a front view of distally resected femur10and caliper device188shown measuring a thickness of resected bone of condyle section184. Condyle section184is shown positioned in front of planar distal femoral surface186rotated ninety-degrees from the orientation in which it was removed. Caliper device188can comprise a sliding thickness gauge formed by moveable jaw190and fixed jaw192. Condyle section184of femur10is shown positioned between fixed jaw190and moveable jaw192of caliper device188. Fixed jaw192and moveable jaw190can function as a thickness gauge, or caliper, that provides an indication of the measured thickness of condyle section184using scale194. Assuming the thicknesses of the distal condyles of the prosthetic femoral component to be sued in the kinematic alignment procedure are 9 millimeters, the resection of a worn condyle should measure approximately 6 mm thick and an unworn condyle should be approximately 8 mm thick (compensating for approximately 1 mm blade thickness). After each of distal medial and lateral condyles156M and156L are resected, a thickness of each of the two resected bones can be measured to confirm that the target medial and lateral resection thicknesses were obtained. Alternatively, the first resection can be performed and measured, and then a second resection can be performed and measured to achieve the desired amount of bone removal.FIG.11shows caliper device188being used, but any tool described herein can be used. Once the desired thickness of condyles156M and156L has been achieved, distal femoral cutting guide166can be removed from femur10, such as by withdrawing intramedullary rod164from intramedullary canal152. FIG.12is a perspective view of femoral sizer196coupled to distally-resected femur10to size femur10and prepare holes for mounting a 4-in-1 femoral cutting guide. Femoral sizer196can comprise stylus198, feet200, slide post202, rotation body204and pivot point206. Feet200can be positioned against posterior surfaces of medial and lateral condyles156M and156L and stylus can be positioned against an anterior surface of femur10by sliding stylus on slide post202. Slide post202can be provided with indicial to indicate an anterior-posterior size of femur10. Stylus198can be rotated on slide post202and can be slid in an inferior-posterior direction to contact femur10in a desired location to determine an A-P size for a femoral implant. Additionally, rotation body204can be pivoted relative to other components of sizer196at pivot point206to set a desired rotation for the femoral implant. For exemplary kinematic alignment procedures, the femoral rotation should be, and typically is, set to 0°. With sizer196positioned in the desired location and adjusted to the desired settings, holes can be drilled into planar distal femoral surface186at drill guide bores208A and208B using drill bit210and any suitable drilling device. After holes are drilled using drill guide bores208A and208B, femoral sizer196can be removed from femur10. In an example, a femoral sizer that can be used in the present procedure is described in U.S. Pat. No. 9,693,881 to Lorio et al., which is assigned to Biomet Manufacturing, LLC, the contents of which are hereby incorporated in their entirety by this reference, can be used to size femur10.FIG.12illustrates one exemplary scenario, i.e., an example device and procedure, for attaching a 4-in-1 cutting guide, but other scenarios can be used to attach a 4-in-1 cutting guide or other cutting guides to femur10. FIG.13is a perspective view of femoral cutting guide102shown mounted to femur10and aligned with a proximal end of a tibia12at tibial plateau158. In the illustrated embodiment, femoral cutting guide102comprises a 4-in-1 cutting guide or block. Pins16A and16B can be used to attach femoral cutting guide102to planar distal femoral surface186. For example, pins16A and16B can be inserted into anchor pin bores134A and134B and into holes in planar distal femoral surface186produced using drill guide bores208A and208B (FIG.12). Femoral cutting guide102can be used to perform various resections of a distal portion of femur10using slots118A-118D. However, in an example procedure of the present application, further resecting of femur10is not performed until after tibial cutting guide104(FIG.14) is placed using femoral cutting guide102as a reference via tibial positioner device100. Thereafter, femur10and tibia12can be resected in any order. In exemplary embodiments of procedures described in the present application, it is desirable that the position and location of the proximal resection of tibia12be aligned relative to the femoral resections. For kinematic alignment, it can be desirable to reference the proximal tibial resection from the distal posterior femoral resection, such as can be produced by cutting slot118A. For example, it can be desirable that the proximal tibial resection is parallel to the distal posterior femoral resection and that the proximal tibial resection is spaced from the distal posterior femoral resection a particular distance D. In an example, distance D is approximately 19 mm. However, in other examples, distance D can be greater than 19 mm given specific factors of a particular patient, the particular prosthetic implant devices to be implanted, etc. Previously, distance D was measured with a manual, free-hand process by placing an osteotome or spacer block underneath femoral cutting guide102. Marking used to indicate where the resection should be placed on tibia12were manually placed on tibia12and, as such, could be mismarked, erased or obscured by tissue when the resection is finally performed. Tibial positioner device100of the present application removes the free-hand process and precisely aligns femoral cutting guide102with tibial cutting guide104. FIG.14is a side view of 4-in-1 femoral cutting guide102coupled to proximal tibial cutting guide104via an embodiment of tibial positioner device100of the present application. Femoral cutting guide102can be attached to femur10using pins16A and16B, as described above. Tibial positioner device100can be attached to proximal tibial cutting guide104by inserting pins116A and116B into mounting bores140A and140B (FIG.6). Tibial positioner device100can, for example subsequently, be attached to femoral cutting guide102by inserting pins114A and14B into mounting bores136A and136B (FIG.6). As such, cutting slot120A can be positioned relative to cutting slot118A by the geometry of tibial positioner device100. In example configurations, femoral coupling block108and tibial coupling block110are configured so that pins114A and114B will be parallel to pins116A and116B. Likewise, mounting bores136A and136B of femoral cutting guide102can be configured to be parallel to cutting slot118A, and mounting bores140A and140B of tibial cutting guide102can be configured to be parallel to cutting slot120A. As such, when pins114A and114B and pins116A and116B are used to couple femoral cutting guide102and tibial cutting guide104via tibial positioner device100, cutting slots118A and120A will be parallel to each other. Additionally, extension112, pins114A,114B,116A and116B can position cutting slot120A perpendicular to posterior surface211of femoral cutting guide102. The length of extension112can determine the distance between cutting slots118A and120A. As discussed above, extension112can be adjustable so that a surgeon can set the distance between cutting slots118A and120A to a desired length. FIG.15is a perspective view of proximal tibial cutting guide104ofFIG.14attached to tibia12via pins212A,212B and212C and cutting blade214of cutting device216inserted through cutting slot120A of proximal tibial cutting guide104to resect a proximal portion of tibia12. Pins212A-212C can be inserted into holes of anchor pin bore groupings138A to hold tibial cutting guide104in place relative to tibia12. Multiple pins are placed on one side of cutting guide104to prevent rotation of cutting guide104without interrupting access to cutting slot120A. Cutting device216can comprise any suitable cutting device, such as an oscillating or reciprocating saw device. Blade214can be inserted through cutting slot120A to engage the proximal portion of tibia12. Blade214can be manipulated to remove tibial plateau158(FIG.14) to leave resected tibial surface218. In an embodiment, resected tibial surface218is planar. By using tibial positioner device100of the present application, resected tibial surface218can be positioned relative to geometry of tibia12so that a prosthetic tibial component attached to tibia12will kinematically align with a prosthetic femoral component attached to femur10. In particular, resected tibial surface218can be positioned relative to planar distal femoral surface186(FIG.13) so that first kinematic axis96and second kinematic axis97(FIGS.4A-4C) will be positioned to the natural joint line of the anatomic femur10and tibia12. FIG.16shows block diagram300illustrating an embodiment of a method for preparing a tibia and a femur for a total knee arthroplasty procedure, particularly one suitable for kinematic alignment of the tibia and femur. At step302, a knee joint can be positioned in flexion to expose the distal condylar portion of the knee and the proximal anterior portion of the tibia. In an example, the knee joint is put in approximately ninety degrees of flexion. At step304, an intramedullary canal can be produced in the femur using any suitable method and device. In an example, the intramedullary canal is positioned along the anatomic axis of the femur. The produced intramedullary canal can be suctioned to remove bone debris. At step306, a distal femoral cutting guide can be attached to the femur. In an example, an intramedullary rod is inserted into the intramedullary canal to facilitate placement of the distal femoral cutting guide. Additionally, a valgus alignment guide can be coupled to the intramedullary rod to position the distal femoral cutting guide and ensure alignment of the distal femoral cutting guide with the anatomy of the femur. At step308, the distal-most portions of the medial and lateral condyles can be resected. For example, a cutting blade can be inserted through a cutting slot or positioned against a cutting surface of the distal femoral cutting guide to resect the condyles. At step310, thickness of resected condyles can be measured, such as by using a caliper. It is desirable that the thickness of the resected condyles be at least 6 mm to, for example, ensure proper fit with prosthetic devices. If 6 mm of removed condyle thickness is not obtained, the distal end of the femur can be additionally cut to remove more bone matter. At step312, a femoral sizer can be attached to the resected distal femur. In examples, an adjustable sizer can be used to find the appropriate femoral size component and also to set the amount of femoral implantation rotation that is desired. The femoral sizer can be used to provide pin placement for a distal femoral cutting guide, such as a 4-in-1 cutting block. At step314, select 0° of femoral rotation on the femoral sizer. In kinematic alignment procedures the interior-exterior rotation can be, and typically is, set to zero degrees to ensure kinematic axes properly align. In other examples, femoral sizers that are fixed for zero degrees of rotation can be used. At step316, a 4-in-1 cutting block can be attached to the distally resected surface of the femur. For example, pins placed with the sizer can be used to attach the 4-in-1 cutting block to the femur. At step318, a tibial cutting guide can be attached to a tibial positioner device, such as ones described with reference toFIGS.5-7B. At step320, the tibial positioner device can be attached to the 4-in-1 cutting block to position the tibial cutting guide relative to the tibia and the 4-in-1 cutting block. At step322, the resection gap between the posterior femoral resection surface and the proximal tibial resection surface can be verified, such as by visual inspection and measurement. If the resection gap is not set to a minimum tibial resection gap distance corrective action can be taken. For example, the anatomy can be adjusted or the tibial cutting guide can be repositioned. In an example, an adjustable tibial positioner device can be adjusted to increase the resection gap. In an example, the minimum tibial resection gap can be 19 mm. At step324, the proximal tibia can be resected. In an example, the tibial cutting guide can be attached to the tibia with pins and the tibial positioner device can be uncoupled from the tibial cutting guide. Any suitable cutting device can be used. At step326, posterior and anterior surfaces of the femur can be resected using cutting slots on the 4-in-1 cutting block. In embodiments, the femur can be resected before the tibia is resected, after the tibial positioner device is removed. As discussed, the tibial positioner device can help ensure that the proximal tibial resection is positioned the desired distanced away from the posterior femoral resection. Additionally, the tibial positioner device can help ensure that the proximal tibial resection plane is oriented in the desired orientation relative to the posterior femoral resection plane, such as in a parallel relationship. VARIOUS NOTES & EXAMPLES Example 1 can include or use subject matter such as a total knee arthroplasty positioning system that can comprise: a tibial positioner device that can comprise: a femoral coupling block that can include first and second laterally spaced coupler pins extending therefrom in a first plane, a tibial coupling block that can include third and fourth laterally spaced coupler pins extending therefrom in a second plane, and an extension that can vertically couple the femoral coupling block and the tibial coupling block such that the first plane and the second plane being parallel to each other; and a tibial cutting guide that can comprise a tibial guide body, first and second coupling bores that can extend into the tibial guide body and configured to receive the third and fourth laterally spaced coupler pins, and a cutting surface that can extend along the tibial guide body in a cutting plane parallel to the second plane. Example 2 can include, or can optionally be combined with the subject matter of Example 1, to optionally include first and second laterally spaced coupler pins that can slidably disengage from within the first and second coupling bores. Example 3 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1 or 2 to optionally include an extension that can comprise first and second extension pins. Example 4 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1 through 3 to optionally include an extension that can adjustably couple the femoral coupling block and the tibial coupling block. Example 5 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1 through 4 to optionally include an extension that can position the cutting plane 19 mm below the first and second laterally spaced coupler pins. Example 6 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1 through 5 to optionally include a tibial cutting guide that can further comprise a plurality of pin-placement bores extending into the tibial guide body and spaced medial-laterally from each other. Example 7 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1 through 6 to optionally include a posterior face of the tibial guide body that is arcuate. Example 8 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1 through 7 to optionally include a femoral cutting guide that can comprise a femoral guide body, third and fourth coupling bores extending into the femoral guide body and that can be configured to receive the first and second laterally spaced coupler pins, first, second, third and fourth cutting slots that can extend into the femoral guide body in planes oblique to each other, and first and second pin placement bores that can extend into the femoral guide body spaced medial-laterally from each other. Example 9 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1 through 8 to optionally include a tibial coupling block that can include a first posterior face from which the first and second laterally spaced coupler pins extend, a femoral coupling block that can include a second posterior face from which the third and fourth laterally spaced coupler pins extend, and an extension that can couple the femoral coupling block and the tibial coupling block such that the first posterior face is anterior-posteriorly offset from the second posterior face toward the extension. Example 10 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1 through 9 to optionally include a posterior face of the femoral guide body that is flat. Example 11 can include or use subject matter such as a method of performing resections for kinematic alignment in a total knee arthroplasty that can comprise positioning a knee joint such that a tibia is located in a flexion position relative to a femur, resecting a distal end of the femur to remove distal-most portions of medial and lateral condyles to form a distal resected surface, coupling a femoral cutting guide to the femur such that a flat posterior surface of the femoral cutting guide is flush with the distal resected surface, coupling a tibial cutting guide to a tibial positioning device, the tibial cutting guide including a proximal tibial cutting guide surface, coupling the tibial positioning device to the femoral cutting guide such that the flat posterior surface of the femoral cutting guide is perpendicular to the proximal tibial cutting guide surface, and resecting a proximal portion of the tibia using the proximal tibial cutting guide surface. Example 12 can include, or can optionally be combined with the subject matter of Example 11, to optionally include a femoral cutting guide that can include a posterior cutting slot disposed in a first cutting plane, a tibial cutting guide that can include a superior cutting slot disposed in a second cutting plane, and coupling the tibial cutting guide and the femoral cutting guide with the tibial positioning device so that the first cutting plane and the second cutting plate are parallel to each other. Example 13 can include, or can optionally be combined with the subject matter of one or any combination of Examples 11 or 12 to optionally include coupling the tibial positioning device to the femoral cutting guide to position the first cutting plane at least 19 mm away from the second cutting plane. Example 14 can include, or can optionally be combined with the subject matter of one or any combination of Examples 11 through 13 to optionally include coupling the tibial cutting guide to the tibia using a plurality of pins extending through the tibial cutting guide. Example 15 can include, or can optionally be combined with the subject matter of one or any combination of Examples 11 through 14 to optionally include removing the tibial positioning device from the tibial cutting guide before resecting the proximal portion of the tibia. Example 16 can include, or can optionally be combined with the subject matter of one or any combination of Examples 11 through 15 to optionally include resecting the distal end of the femur to remove distal-most portions of the medial and lateral condyles to resect at least 6 mm of condyle from the femur. Example 17 can include, or can optionally be combined with the subject matter of one or any combination of Examples 11 through 16 to optionally include using an adjustable distal femoral sizer to size an anterior-posterior dimension of the femur before resecting the distal end of the femur, wherein the adjustable distal femoral sizer can be adjusted for zero degrees of external femoral rotation relative to the tibia. Example 18 can include, or can optionally be combined with the subject matter of one or any combination of Examples 11 through 17 to optionally include resecting a posterior portion of the femur using the femoral cutting guide. Example 19 can include or use subject matter such as a total knee arthroplasty positioning system that can comprise a distal femoral cutting guide having a posterior cutting guide slot, a proximal tibial cutting guide having a proximal cutting guide slot and a positioner device coupling the distal femoral cutting guide and the proximal tibial cutting guide such that the posterior cutting guide slot and the proximal cutting guide slot are parallel. Example 20 can include, or can optionally be combined with the subject matter of Example 19, to optionally include a positioner device that can couple the distal femoral cutting guide and the proximal tibial cutting guide such that the posterior cutting guide slot and the proximal cutting guide slot are adjustably offset in a superior-inferior direction. Each of these non-limiting examples can stand on its own, or can be combined in various permutations or combinations with one or more of the other examples. The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention can be practiced. These embodiments are also referred to herein as “examples.” Such examples can include elements in addition to those shown or described. However, the present inventor also contemplates examples in which only those elements shown or described are provided. Moreover, the present inventor also contemplates examples using any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein. In the event of inconsistent usages between this document and any documents so incorporated by reference, the usage in this document controls. In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of “at least one” or “one or more.” In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. In this document, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, a system, device, article, composition, formulation, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Method examples described herein can be machine or computer-implemented at least in part. Some examples can include a computer-readable medium or machine-readable medium encoded with instructions operable to configure an electronic device to perform methods as described in the above examples. An implementation of such methods can include code, such as microcode, assembly language code, a higher-level language code, or the like. Such code can include computer readable instructions for performing various methods. The code may form portions of computer program products. Further, in an example, the code can be tangibly stored on one or more volatile, non-transitory, or non-volatile tangible computer-readable media, such as during execution or at other times. Examples of these tangible computer-readable media can include, but are not limited to, hard disks, removable magnetic disks, removable optical disks (e.g., compact disks and digital video disks), magnetic cassettes, memory cards or sticks, random access memories (RAMs), read only memories (ROMs), and the like. The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is provided to comply with 37 C.F.R. § 1.72(b), to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description as examples or embodiments, with each claim standing on its own as a separate embodiment, and it is contemplated that such embodiments can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

11857203

DETAILED DESCRIPTION OF THE INVENTION The reference numeral30designates generally a rotary oscillating surgical tool useful particularly in the modification or removal of hard tissue such as bone, cartilage and disc tissue. The surgical tool30is a handheld tool with a housing32providing a handle34for manually gripping the tool30for use during a surgical procedure. While one shape and style of handle34is illustrated, any suitable shape and style of handle can be provided. For example, a right angle pistol grip may be added. Additionally, the housing may have a narrow front portion for a smaller pencil-like “precision grip”, while the larger remaining portion is sized to balance in the user's hand, such as in the web area between the index finger and thumb for allowing better control with less fatigue. The tool30can be used in surgical operations, such as spinal surgery, wherein tissue such as bone, cartilage and disc material that is preferably of a non-fibrous tissue type may be modified or removed, such as from the spine of a patient. The tool30has an output shaft36, which is driven to rotate in an oscillating manner of two alternate directions about the longitudinal axis35of the shaft36. Shaft36is provided with a cutting tool or cutter38positioned and secured to a distal end portion of the shaft36. The cutter38is driven to rotate in alternate directions, like the shaft36, with a limited range of angular displacement of rotation. It has been found that such oscillatory rotation is effective in cutting or modifying hard tissue like bone, cartilage and portions of discs. It has also been found that this oscillatory rotation reduces the risk of damage to fibrous tissue like muscle and nerve. The tool30can receive energy for its operations from an external supply, such as a direct current power supply cord40. A power control switch42may be provided on the housing32for controlling the operation of the tool30, such as in an on and off manner and/or in a variable rotational speed manner. A light source44may also be provided on the housing32for illuminating the surgical site. Such a light source may be a light emitting diode (LED) which can be powered directly or indirectly by energy from the cord40. FIG.2illustrates the internal components of the tool30. An energy source may be provided by a battery supply46mounted in the housing32. The battery supply46may be charged by the power cord40. Electronics48are provided in the housing32for controlling the operation of the tool30. The power switch42may alternatively be located at the distal end of the housing as opposed to the illustrated position at the intermediate section of the housing32. A plurality of indicator lamps50may also be provided on the housing32, and can be LEDs for indicating operational characteristics of the tool30, such as the state of charge of the battery supply46. Alternately, the batteries46can be eliminated in favor of the cord40being connected to a source of electrical energy. Additionally, the motor52can be powered by compressed air, a vacuum or any other suitable source of energy that would, on demand, effect rotation of a rotor portion of the motor52. The motor52is suitably mounted in the housing32, wherein a portion of the motor, a rotor, is free to rotate and ultimately drive the shaft36. A portion of the motor52is fixed against rotation in the housing32as is known in the art, for example, a motor housing and/or stator. The motor52drives the shaft36through a transmission54that is operable for converting continuous rotary motion from the motor52to rotary oscillation to the shaft36. The shaft36is suitably mounted in the nose57of the housing32as in bearings59. The shaft36may be angled relative to the longitudinal axis of the housing32, as depicted inFIG.2, for ergonomics. Cooling fins or a cooling fan, not shown, may be attached to or near the motor52for cooling the motor and/or the tool30. The transmission54, as best seen inFIGS.3-9, is positioned in the housing32and operably couples the shaft36to the motor52, and is operable to convert the continuous rotary motion of the output shaft60of the motor52to oscillating rotary motion of the shaft36. By oscillating rotary motion, it is meant that the shaft36will rotate a portion of a complete revolution, first in one rotation direction then in another rotation direction, say first counterclockwise, then clockwise, then counterclockwise again and so on. To effect this movement, the transmission54comprises two sections. The first section is designated generally61and is operable to convert the rotary motion of the shaft60of the motor52to reciprocating generally linear motion of a portion thereof, and the second section is designated generally62and is operable to convert that reciprocating generally linear motion to oscillating rotary motion. In the illustrated embodiment, the transmission section61is in the form of a Cardan mechanism that utilizes an internal toothed ring gear64and an external toothed pinion gear65, with the pinion gear65being positioned inside of and having its external gear teeth in engagement with the internal gear teeth of the ring gear64. The gear ratio of the ring gear64to pinion gear65is 2:1. The ring gear64is suitably fixed in the housing32to prevent its motion relative to the housing32. The pinion gear65is suitably mounted to a crank arm66, which in turn is secured to the shaft60of the motor52and is offset from the axis of rotation of the shaft60, whereby the pinion gear65revolves about the axis of rotation of the shaft60while inside the ring gear64. Preferably, the crank arm66has a counterweight67opposite of where the pinion gear65is mounted to the crank arm66. In a Cardan mechanism, one point on the pinion gear will move generally linearly in a reciprocating manner within the ring gear associated therewith. In the illustrated embodiment, as oriented as seen inFIG.4, the path of movement of this point is timed to move in a generally transverse plane relative to a portion of the first section61of the transmission54. Secured to the pinion gear65, preferably in an integral manner, is a driver arm69that extends forwardly of the ring gear64for receipt in a follower70to effect movement of the follower70in response to movement of the arm69. The follower70is suitably mounted in the housing32in a manner to permit its pivoting movement about an axle71. The transverse linear movement of a spot on the pinion gear65is generally transverse to the longitudinal axis of elongate slot74in the follower70. The axle71is suitably mounted in bearing supports73that are in turn suitably mounted to the housing32. While only one bearing support73as shown, it is preferred that each end of the axle71have a bearing73associated therewith. It is to be understood that the axle71could utilize the follower70as a bearing for rotation of the follower70about the axle71, and have the axle71mounted to the housing32in a fixed manner. The driver arm69is received within the elongate slot74for effecting movement of the follower70in a rotary oscillating manner. The follower70moves in an oscillating rotary manner about the axis of the axle71. When a portion of the driver arm69is moving in its linear path, portions of the arm69engage sides of the slot74to effect movement of the follower70in response to movement of the driver arm69. This movement can be seen in various orientations illustrated inFIGS.5-9. In the illustrated structure, the driver69is offset to the outside of the outside diameter of the pinion gear65, and thus its central axis does not move in a linear path, but will move in a series of arcs that are elongated in a horizontal plane and reduced in the vertical direction as seen in the orientation of the tool30inFIG.2. This back-and-forth and up-and-down movement is accommodated by constructing the slot74to be elongated, as best seen inFIG.4. As the driver69moves in its path, it affects oscillating rotary motion of the follower70about the axle71. Two counterclockwise and two clockwise oscillations of the cutter38are effected, and four oval paths by a portion of the driver69are traversed for each revolution of the pinion gear65within the ring gear64. The follower70is provided with a drive gear, such as a sector gear76, that is operably coupled to a driven gear member77secured to the shaft36. As the follower70moves, the shaft36moves in response thereto by engagement between the gears76and77. Because the follower70moves in a rotary oscillating manner, the shaft36also moves in a rotary oscillating manner. The components of the transmission sections61,62are configured relative to one another such that, when the rotary oscillating movement changes direction at the shaft36, the applied torque by the motor52would be high; while at the center of one oscillation, the applied torque by the motor52would be lower. This assists in providing a high starting torque for the cutter38to reverse rotation direction. All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference. It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein. One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary, and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.

11857204

DETAILED DESCRIPTION OF THE INVENTION The following description of the different embodiments of the surgical instrument25is—exemplarily but not limiting—directed to a surgical drilling device configured as a surgical power drill2, wherein:the drive unit comprises a motor and a spindle13which is drivable by the motor and has a longitudinal axis7in the direction of which the drilling path extends;the engagement means are configured as a chuck6permitting to clamp a drill bit5; and whereinthe reference position is defined by a surface of an implant26or a bone. The measuring device1can comprise a signal conditioner to convert analog signals generated by a sensor into digitized signals. Furthermore, the processing unit14can be provided with a timer or a clock to record the relative position x with respect to time. Definitions The following definition of terms and wordings currently used describe the exact meaning thereof as they are used throughout the present specification: Position x of the cutting tip of the drill bit relative to a surface of a bone or of an implant: During a drilling process the distance x covered by the housing12in the direction of the longitudinal axis7of the spindle13and relative to a surface of a bone or of an implant26is related with the position x of the cutting tip9of the drill bit5relative to a surface of a bone or of an implant26in the drilling direction because the drill bit5is firmly fixed in the chuck6of the surgical power drill2and positioned at the beginning of the drilling process as described in detail below. Depending on the object into which a hole is drilled, e.g. a bone, there may be more than one point of transition21of the cutting tool or drill bit5from a first medium to a second medium, e.g. a first transition from cortical bone to cancellous bone (spongy bone) and a second transition from cortical bone to surrounding tissue. With respect to the one or more reference graphs GRefthe reference point of a transition is denoted with the reference numeral21′. FIG.1illustrates an embodiment of the surgical power drill2according to the invention wherein the surgical power drill2essentially includes a housing12in which a motor and a spindle13driven by the motor are accommodated, a measuring device1releasably attached or fixed to the housing12and an adaptor15to secure the measuring device1to the housing12. The spindle13has a longitudinal axis7and comprises a chuck3at a front end for clamping a drill bit5. The measuring device1comprises a first member3, which is in a fixed position relative to the housing12and a longitudinal second member4, which is exemplarily but not limiting displaceable parallel or coaxial to the longitudinal axis7of the spindle13relative to the first member3. Alternatively, the measuring device1can be arranged at the housing12so that the second member4is displaceable at an angle relative to the longitudinal axis7of the spindle13. The systematic error which occurs due to this angulation (cosine error) can be easily compensated. This configuration has the advantage that the reflector can be smaller so that the measuring tip can be arranged closer to the drill bit5. The displaceable second member4has a front end10, wherein in use the front end10of the displaceable second member4abuts the bone surface or a surface of an implant26, e.g. a bone plate or a drill sleeve. The drill bit5can be clamped in the chuck6and is provided with a cutting tip9. Furthermore, the displaceable second member4can comprise a drill sleeve23extending in the direction of the longitudinal axis7to the front end10of the second member4. The measuring device1comprises a laser device for linear displacement assessment. This laser device comprises a laser module18with a laser light emitting means, a reflector20attached to a drill sleeve23forming the second member4which is slideable along the drill bit5and at least one electronic light sensor19, which is, exemplarily but not limiting, configured as a charge-coupled device (CCD) to perform laser triangulation for linear displacement assessment. In another alternative embodiment the linear displacement assessment can be performed by using ultra sound position sensors. To incorporate screw length determination in the drilling procedure so as to eliminate the step of depth measurement after drilling the hole in the bone the configuration of the measuring device1is based on the fact that during drilling an acceleration peak of the drill bit5occurs when the cutting tip9of the drill bit5exits a bone cortex as this is an unavoidable attribute of handheld drilling. Consequently, the housing12of the surgical power drill2together with the first member3of the measuring device1is subjected to the same acceleration. The surgical instrument25further comprises a processing unit14and a digital data storage. The processing unit14is electronically directly or wirelessly connected to the measuring device1and suitably programmed to record a graph G of the distance [x(t)] covered by the cutting tool or drill bit5relative to the reference position and with respect to time during a cutting or drilling process. In the digital data storage reference data are stored which include one or more data sets each specifying a reference graph GRefof the distance [x(t)] covered by a cutting tool or drill bit5with respect to time and within a time window11in the range of a transition of the cutting tool or drill bit5from a first medium having a first density to a second medium having a different second density during a cutting or drilling process. As illustrated inFIG.2multiple reference graphs GRefcan be stored in the digital data storage, representing various drilling or cutting characteristics. The processing unit14is suitably programmed to repeat the step of quantifying the agreement between the recorded graph G or the at least one portion of the recorded graph G to the reference graphs GRefby means of a similarity measure for all stored reference graphs GRefand finding the overall best fit between graph G and all reference graphs GRefto identify the position x of transition21in the recorded graph G. Each of the one or more reference graphs GRefdefines a reference point of a transition21′ of the cutting tool or drill bit5from a first medium to a second medium, wherein the time window11includes a first time period before the reference point of a transition21′ and a second time period after the reference point of a transition21′. The processing unit14is suitably programmed to compare the recorded graph G or at least one portion of the recorded graph G with the at least one reference graph GRefby means of a similarity measure to quantify the agreement between the recorded graph G or at least one portion of the recorded graph G and the at least one reference graph GRefto find the position of a transition21in the recorded graph G. In the case that at least one portion of the recorded graph G is used for the comparison the at least one portion of the recorded graph G extends at least in a period of time as specified by the time window11. The processing unit14is programmed to compute in real-time. The digital data storage further stores a predefined threshold value for the similarity measure and the processing unit14is programmed to trigger a transition event and report the position x of transition21if the threshold value for similarity is reached. A schematic representation of the process performed by the processing unit14in the case of drilling a hole through a bone is illustrated inFIG.3. The processing unit14can report two values for the position of a transition21of the drill bit5from a first medium to a second medium which occur at the positions where the cutting tip9of the drill bit9exits the near cortex [x(ta)], respectively the far cortex [x(tb)] of a bone so that the surgeon can then decide whether unicortical or bicortical bone screws are to be applied. The digital data storage is particularly configured as a buffer to hold an actual time window of the current graph G of the distance [x(t)] at least as large as the window11of the reference graph GRef. Exemplarily but not limiting, each reference graph GRefis specified by about 30 values for the distance [x(t)] covered by a cutting tool or drill bit5which are subsequent with respect to time within the first time period before the reference point of a transition21′ and by about 10 values for the distance [x(t)] covered by a cutting tool or drill bit5which are subsequent with respect to time within the second time period after the reference point of a transition21′. Exemplarily, the first time period before the reference point of a transition21′ amounts to about 0.3 seconds and the second time period after the reference point of a transition21′ amounts to about 0.3 seconds. Additionally, the reference data inherently require a positive advance velocity v>0 of the cutting tool or drill bit5in the first time period before reaching the reference point of a transition21′. The similarity measure applied to select the portion of the graph G which best fits the reference graph GRefto find the position x of transition21in the recorded graph G can be a pattern recognition approach, exemplarily but not limiting a shape context descriptor. The reference data specifies a statistical representation of a plurality of prospectively recorded graphs G in the range of a transition of a cutting tool or drill bit5from a first medium having a first density to a second medium having a different second density during a cutting or drilling process. Furthermore, the reference data are continuously amended according to the use of the cutting or drilling device, wherein the amendment of the reference data can be performed by machine learning algorithms, preferably by involving use of a neural network. The measuring device1particularly measures and records the relative motion between the displaceable second member4and the first member3which is fixed with respect to the housing12. Since the drill bit5is firmly clamped in the chuck6the relative motion between the displaceable second member4and the first member3coincides with the relative motion of the cutting tip9of the drill bit5with respect to the front end10of the displaceable second member4. Therefore, the measuring device1measures and records the relative motion of the drill bit5in the drilling direction in real time with respect to the bone surface or to the surface of an implant on which the front end10of the displaceable second member4of the measuring device1abuts. The motion of the drill bit5relative to the displaceable second member4of the measuring device1is a one-dimensional translational motion and the position x of the cutting tip9of the drill bit5relative to the front end10of the displaceable second member4at any moment is given by the x coordinate of the cutting tip9along the x-axis8which in this case forms the reference frame. The position x or x coordinate of the cutting tip9is set to 0 at the beginning of the drilling procedure, e.g. when the cutting tip9of the drill bit5is flush with the front end10of the displaceable second member4. For this purpose the position x or x coordinate of the cutting tip9of the drill bit5with respect to time is recorded by the processing unit14which is integrated in the first member3of the measuring device1. Exemplarily, but not limiting, the processing unit14is configured as a digital processing unit and comprises a microprocessor having a processor register to record the position of the second member4relative to the first member3. As described above the position of the second member4relative to the first member3coincides with the position x or x coordinate of the cutting tip9of the drill bit5relative to the front end10of the displaceable second member4. The drill distance to the exit from the second cortex, i.e. the position x or x coordinate of the cutting tip9of the drill bit5when the cutting tip9exits the far cortex is automatically computed based on the process performed by the processing unit14. Based on this position x or x coordinate the required screw length, preferably including a safety margin can be estimated. For this purpose the processing unit14can comprise a data memory to store data related to bone screw lengths, preferably including safety margin, screw head length, tip section length and screw length increments. The measuring device1and particularly the displacement sensors can be either integrated in the housing12or can be temporarily attachable thereto. In a temporarily attachable configuration the measuring device1comprises attachment means in the form of an adaptor15which is releasably affixable to the housing12of the surgical power drill2. This adaptor15is exemplarily but not limiting configured as an annular framework attachable to the housing12by means of a press fit or via a clamp collar. Alternatively, the measuring device1can comprise clamps to releasably affix the measuring device1to the housing12. The measuring device1can comprise a wireless communication device, exemplarily configured as a Bluetooth module with signal conditioner. Via the wireless communication device the data may be transmitted wirelessly to an external computer with monitor, a tablet computer, a smartphone, a smartwatch or a smart glass to compute or indicate the derived information, i.e. the measured position of the cutting tip of the drill bit with respect to time, the computed velocity with respect to time and the computed point of transition may be transmitted wirelessly to an external device such as a computer with monitor, a tablet computer, a smartphone, a smartwatch or a smartglass. Alternatively, the derived data may be provided on a display or speaker locally mounted to the surgical power drill2. Additionally, the measuring device1comprises a sterilizable casing16to enclose the processing unit14, the wireless communication device and the power supply22for the measuring device1, wherein the power supply22includes one or more rechargeable or non-rechargeable batteries arrangeable in the casing16. Furthermore, the device25can additionally comprise a calibration device27as illustrated inFIGS.7and8and described in more detail below. Another embodiment of the device25according to the invention is illustrated inFIG.4, wherein the device25ofFIG.2differs from the embodiment ofFIG.1only therein that the processing unit14is an external unit, e.g. a computer with monitor, a tablet computer, a smartphone, a smartwatch or a smartglass, and that the measuring device1comprises a wireless data transmission device17and the processing unit14includes a wireless data receiving device so that the measured distance x covered by the housing12in the direction of the longitudinal axis7and relative to a surface of an implant26or a bone can be transmitted from the measuring device1to the external processing unit14and recorded with respect to time. The external processing unit14can comprise a microprocessor similar to the embodiment ofFIG.1or can comprise a central processing unit. A further embodiment of the device25according to the invention is illustrated inFIGS.5and6, wherein the measuring device1of the embodiment ofFIGS.5and6differs from the embodiment ofFIG.1therein that the first member3including the laser module18for emitting a laser beam and the receiver for triangulation, e.g. an electronic light sensor19in the form of a photodiode or a charge-coupled device (CCD) is configured as a part of an electronic module31. This electronic module31is insertable into a hollow space32formed in the handle33of the housing12, wherein the hollow space32extends from an opening34at the bottom of the handle33to the top part35of the housing12. The opening34can be closed by means of a cover36which is attachable to the bottom of the handle33. Apart from the first member3the electronic module31comprises a display30which is arranged in an upper part37of the electronic module31, wherein this upper part37is shaped and dimensioned to fit into a respective cavity38configured in the top part35of the housing12. Furthermore, the electronic module31has a lower part40including the laser module18, the electronic light sensor19, the processing unit14and a power supply22for driving the surgical power drill2and for supplying the laser module18, the light sensor19and the processing unit14. Exemplarily, the power supply22can be a battery or an accumulator. The lower part40of the electronic module31is shaped and dimensioned to fit into the hollow space32in the handle33of the housing12. A laser window41is arranged at the front of the lower part40and just below the upper part37of the electronic module31so as to match the laser beam and the electronic light sensor19with respective windows42,43(FIG.6) in the housing12. A first and a second sterile window42,43are arranged in the housing12of the surgical power drill2to provide windows for the laser beam emitted by the laser module18and the reflected beam received by the electronic light sensor19. The first and second sterile windows42,43are arranged in the front of the housing12and—when viewed in a front view—below the longitudinal axis7of the spindle13and located on opposite sides of a middle plane44of the surgical power drill2which contains the longitudinal axis7and at a distance from the middle plane44which permits the laser beam and the reflected beam to pass beside the spindle13and the chuck6of the surgical power drill2. The top part35of the housing12forms a casing16for the display30, wherein the casing16is, exemplarily but not limiting, integral with the housing12of the surgical power drill2and encompasses the cavity38. This casing16comprises a third sterile window45for covering the display30. Further the casing16is arranged at the housing12opposite the handle33of the surgical power drill2. The third sterile window45is angled relative to a plane orthogonal to the longitudinal axis7of the spindle13and directed towards the rear end of the housing12. Exemplarily but not limiting the measuring device1is suitably configured to control the rotational speed of the spindle13of the surgical power drill2so that the power supplied to the electric motor of the power drill2can be shut down when a peak is detected by means of the measuring device1to thereby prevent plunging of the drill bit5. Again another embodiment of the device25according to the invention is illustrated inFIGS.12-15, wherein the measuring device1of the embodiment ofFIGS.12-15differs from the embodiment ofFIG.1therein that the first member3includes an electronic module31which comprises apart from the laser module18for emitting a laser beam and the receiver for triangulation, e.g. an electronic light sensor19in the form of a photodiode or a charge-coupled device (CCD) a display30. Further the electronic module31comprises the processing unit14and the power supply22for the measuring device1. The display30is arranged at the rear side46of the electronic module31. Similarly to the embodiment ofFIG.1the sterilizable casing16is attachable to the surgical power drill2and comprises a cavity38to receive the electronic module31. A sterile front window47is arranged in the front of the casing16to let through the laser beam emitted by the laser module18and the reflected beam reflected by means of the reflector20arranged at the second member4of the measuring device1. The laser module18and the electronic light sensor19which receives the reflected beam to perform the triangulation are arranged laterally spaced from each other in the electronic module31so that—when viewed in a front view of the assembled first member3—the laser beam and the reflected beam pass above the longitudinal axis7of the spindle13. The casing16comprises an adaptor15to secure the first member3of the measuring device1to the housing12, wherein the adaptor15is releasably affixable to the housing12of the surgical power drill2. This adaptor15is, exemplarily but not limiting, configured as an annular framework attachable to the housing12by means of a clamp collar48that is fixable, e.g. to the stationary part of the spindle13by means of a clamping screw49. The clamp collar48is positioned at the casing16laterally offset with respect to a longitudinal central plane of the casing16to permit the laser beam and the reflected beam to pass beside the drill bit5. Furthermore, by means of the adaptor15the casing16is attached to the surgical power drill2at an angle with respect to the longitudinal axis7so that the laser beam is emitted at an angle to the longitudinal axis7permitting a reduced size of the reflector20of the second member4of the measuring device1. The casing16is sterilizable and configured as a separate piece arranged on top of the housing10. The cavity38has an opening at the rear side of the casing16and can be closed by means of a lid51which is rotatable about an axis located at the lower side of the casing16and extending orthogonally to the longitudinal axis. The lid51comprises a sterile rear window52for covering the display30, wherein—when the lid51is closed —the rear window52is angled relative to a plane orthogonal to the longitudinal axis7of the spindle13and directed towards the rear end of the housing12. Exemplarily but not limiting, an actuator53for a power switch of the electronic module31can be arranged at the inside of the lid51so that when the lid51is closed energy is supplied from the power supply22to the electronic components of the measuring device1. To operate the processing unit14, the laser module18and the electronic light sensor19one or more buttons54can be positioned at the rear side of the electronic module31. The sterile rear window52can be provided with recesses so as to provide weakened areas in the rear window52which permit to actuate the one or more buttons54when the lid51is in its closed position. The processing unit14of the embodiments ofFIGS.1,4-6and12-15comprises a microprocessor or a central processing unit which includes a processor register to record the distance x covered by the housing12in the direction of the longitudinal axis7and relative to a surface of an implant26or a bone with respect to time during a drilling process. It has to be noted that real-time feedback of current drill depth alone can be of high value for the surgeon. Further valuable information is delivered by the current drilling speed. This helps the surgeon to control his feed rate to avoid mechanical or heat damage of the bone or it can be used to estimate the bone quality. FIG.16illustrates another embodiment of the reflector20which is not integral with or attached to a drill sleeve23. The reflector20is clampable onto the drill bit5in such a way that it can slide on the drill bit5so that the reflector20is independent from the configuration of the drill sleeve23. The reflector20has a disc shaped portion55and on each side adjoining thereto a clamping portion56comprising longitudinal slots so as to form tongues suitable to exert radial pressure onto the drill bit5. The method for bone screw length estimation from drilling characteristics essentially comprises the steps: A) advancing the surgical power drill2coaxially to the longitudinal axis of the spindle13to drill a hole in a bone and by recording the position (x) of the cutting tip9of the drill bit5relative to a surface of a bone or of an implant26in the drilling direction with respect to time; B) determining the instant when the cutting tip9of the drill bit5exits a cortex of a bone by using the selected reference graph GRefand the reference position of the transition21′ of the drill bit5from a first medium to a second medium defined by the selected reference graph GRef; C) determining the distance [x(t)] covered by the drill bit5at the instant determined under step B); and D) selecting a bone screw having a length corresponding to the distance [x(t)] covered by the drill bit5determined under step C) under consideration of a predefined safety margin. As described above the position x of the cutting tip9of the drill bit5relative to a surface of a bone or of an implant26in the drilling direction is set to zero at the beginning of the drilling process. However, this zero position of the cutting tip9of the drill bit5depends on the fact whether:1) the displaceable second member4comprises a drill sleeve23extending in the direction of the longitudinal axis7to the front end10of the second member4as illustrated inFIGS.3,4and11a-11e; or whether2) the drill sleeve is a separate member previously inserted in the soft tissue covering the bone to be treated; or whether3) the zero position of the cutting tip9is to be set with respect to an implant26, e.g. a bone plate. In case the drill bit5is guided in a drill sleeve23which during drilling contacts or attaches to a bone plate and hence doesn't allow the cutting tip9of the drill bit5to abut the upper surface of the bone plate (FIG.9) a calibration device27providing a physical stop28inside the drill sleeve23at a height corresponding with the upper surface of the bone plate can be used to determine the start point of the measurement (FIG.8). Alternatively, if the lengths of drill bit5and drill sleeve23are known, the start point can be computed from this data. In the case of the above variant1) the method comprises before step A) the following steps:positioning the surgical power drill2relative to a bone so that the front end10of the displaceable second member4and the cutting tip9of the drill bit5abut a surface of a bone; andstoring the relative position as start point (x=0) for the measurement of the position x of the cutting tip9of the drill bit5relative to a surface of a bone in the drilling direction with respect to time. In the case of the above variant2) the method comprises before step A) the following steps:positioning the surgical power drill2relative to a bone so that the front end10of the displaceable second member4abuts a drill sleeve23inserted in the soft tissue covering a bone to be treated; andadjusting the cutting tip9of the drill bit5secured in the chuck6of the surgical power drill2relative to the displaceable second member4so that the cutting tip9of the drill bit5abuts a surface of a bone; andstoring the relative position as start point (x=0) for the measurement of the position x of the cutting tip9of the drill bit5relative to a surface of a bone in the drilling direction with respect to time. In the case of the above variant3) the method comprises before step A) the following steps (FIGS.9and10):positioning the drill bit5secured in the chuck6relative to the displaceable second member4by using a calibration device27(FIGS.7and8) so that front end10of the second member4contacts a surface29of the calibration device27and the cutting tip9of the drill bit5abuts a stop28protruding from the surface29of the calibration device27;storing the relative position as start point (x=0) for the measurement of the position x of the cutting tip9of the drill bit5relative to a surface of a bone or of an implant26in the drilling direction with respect to time; andpositioning the surgical power drill2relative to an implant26, e.g. a bone plate, so that the front end10of the displaceable second member4abuts a surface of the implant26(FIG.9). FIG.17illustrates a further embodiment of the calibration device27. The reflector20as well as the calibration device27, e.g. illustrated inFIGS.7and8can be made for single use. In other embodiments the drill sleeve23according to one of the embodiments illustrated inFIGS.11a-11e,16and17can be configured as a disposable member as well and can for this purpose be connected to the calibration device27via a predetermined breaking point. Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the scope of the appended claims. It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.

11857205

DETAILED DESCRIPTION When referring to specific directions in the following discussion of certain implantable devices, it should be understood that such directions are described with regard to the implantable device's orientation and position during exemplary application to the human body. Thus, as used herein, the term “proximal” means close to the heart and the term “distal” means more distant from the heart. The term “inferior” means toward the feet and the term “superior” means toward the head. The term “anterior” means toward the front of the body or the face and the term “posterior” means toward the back of the body. The term “medial” means toward the midline of the body and the term “lateral” means away from the midline of the body. Also, as used herein, the terms “about,” “generally” and “substantially” are intended to mean that slight deviations from absolute are included within the scope of the term so modified. FIGS.1-4depict a first embodiment of a void filling prosthesis10. The void filling prosthesis10includes a central body11, a medial leg13, and a lateral leg12. In another embodiment, the void filling prosthesis10may include a central body and only a medial leg13or lateral leg12. The central body11is generally cylindrical. However, this cylindrical shape may take the form of a portion that has a constant diameter and a portion that is slightly tapered such that it is generally frustoconical. The central body11includes an aperture18that extends through the central body11in order to allow the passage of an IM stem of a femoral component30. This aperture18forms a wall19, which is integrated with the lateral and medial legs12,13forming a monolithic structure. The lateral and medial legs12,13may be offset posteriorly from a median transverse axis of the central body11. Further, the lateral and medial legs12,13may be located in close proximity, but may be separated generally by a space17that penetrates through both legs and forms a saddle-like structure in order to provide clearance for a femoral cam box33of a femoral component30. This space17forms inner surfaces15a-dthat abut the femoral cam box33when implanted. These inner surfaces15a-dmay be flat, planar walls, or they may be stepped to provide surfaces conducive for bonding with bone cement. Further, inner surface15dmay be obliquely angled with respect to the longitudinal axis of the central body11in order to account for the angle of the IM stem (not shown) with respect to the cam box. Further geometric features may be incorporated into the medial and lateral legs12,13in order to provide clearance for the structure of the femoral component30. For instance, inclined surfaces14a-dmay be fashioned into each leg in order to provide clearance for a bone interface surface35of the femoral component30. The remainder of the lateral and medial legs12,13that has not been shaped to form clearance space is depicted as having a generally frustoconical profile. This geometric profile is preferred in order to conform more closely to bone voids created by the reaming instrumentation. However, this is merely an example of a geometry that the medial and lateral legs12,13may form. The legs12,13may have other geometries, such as box-like geometries. Further, the medial and lateral legs12,13may be symmetric with respect to one another, or they may be asymmetric where one leg12,13may be larger than the other 12, 13 and/or one leg12,13may have a different geometry. A conical structure16a-bmay be disposed at one end of each of the lateral and medial legs12,13. This conical structure16a-bmay help prevent rotation of the prosthesis10when implanted in the bone and help the prosthesis10settle into the proper orientation and more closely conform to the void formed by the reaming instruments. Referring toFIGS.1-4and7-8, each leg12,13is shown to include two removable portions20a-dat an end of each leg12,13. While two removable portions20a-dare shown, this is merely an example. Each leg12,13may include any number of selectively removable portions20a-d, including just one. Alternatively, one leg12,13may include at least one selectively removable portion20a-dwhile the other leg12,13may have no selectively removable portions20a-d. Where one or more selectively removable portions20a-dis removed from a leg12,13, the length of the leg12,13is decreased in order to make room in the joint cavity for a bone augment, for example. This removability provides the operator the operating room capability and flexibility to configure the void filling device10to work in conjunction with a bone augment, or alternatively work where no augment is needed. Thus, each selectively removable portion20a-dis shaped to conform to the geometries of the void filling prosthesis10as though they will never be removed. Further, where these portions20a-dare not removed, they provide structural support to the prosthesis10. Where there are multiple selectively removable portions20a-d, they are layered along the length of each leg12,13as far as needed to accommodate a bone augment. Each selectively removable portion20a-dmay have a first section22a-dmade from a weaker material and a second section21a-fmade from a stronger material, where the two sections21a-f,22a-dare layered along the length of each leg12,13. In a preferred embodiment, the weaker and stronger material may be made from the same metallic material, but the weaker material may have a higher porosity than that of the stronger material allowing for a seamless transition between these two sections21a-f,22a-d, but providing a region for easy separation. Separation is made easier by the fact that the more porous material is easier to separate and that the two sections21a-f,22a-dare visually recognizable indicating the separation location. In one embodiment, the separation location may be designated by a small chamfer to receive a cutting blade between the first section22a-dof one selectively removable portion20a-dand the second section21a-fof another selectively removable portion20a-d. An example of the porous metallic material may be titanium, titanium alloy, stainless steel, cobalt chrome alloys, tantalum or niobium formed by Selective Laser Melting (“SLM”) as described in U.S. Pat. No. 7,537,664 titled “Laser-Produced Porous Surface,” the entirety of which is incorporated-by-reference herein fully set forth herein and which is assigned to the same entity as the present invention. Additional examples are disclosed in U.S. application Ser. No. 11/027,421, filed Dec. 30, 2004, Ser. No. 11/295,008, filed Dec. 6, 2005, and Ser. No. 13/441,154, filed Apr. 6, 2012, and U.S. Pat. Nos. 8,350,186 and 8,147,861, the entireties of which are incorporated-by-reference herein as if fully set forth herein. In an alternative embodiment, the weaker material may have the same porosity as the stronger material, but may be constructed from a material that has a lower modulus than the stronger material. In another embodiment, the entire void filling prosthesis10may be constructed from a porous metallic material including the selectively removable portions20a-dwith little or no variations in the porosity, but that the selectively removable portions20a-dhave score marks to designate the cutting points. In a further embodiment, the first section22a-dmay have an outer shell that is the same porosity as the remainder of the void filling prosthesis10, and an interior portion constructed from the weaker material. These selectively removable portions20a-dmay be removed by cutting along the weaker section22a-dgenerally parallel and adjacent the stronger section21a-fof another selectively removable portion20b,20dthat is more proximate the central body using a cutting device. For instance a cutting device may be a guillotine-like device, an example of which is disclosed in U.S. application Ser. No. 12/002,002, filed Dec. 13, 2007, the entirety of which is incorporate-by-reference herein as if fully set forth herein. Where the selectively removable portion20b,20dis the last selectively removable portion along the length of that particular leg12,13, the leg12,13may have a layer of stronger material21c,21fjust adjacent to the weaker section22b,22dof that selectively removable portion20b,20dto facilitate removal. The remainder of the void filling prosthesis10may also be partially constructed from porous metallic material as described above. In one embodiment, the surfaces in contact with the femoral component30, such as internal surfaces15a-d, may be constructed of solid metallic material, such as titanium as an example, while the remainder of the void filling prosthesis10may be constructed of porous metallic material. FIGS.5and6depict an alternative embodiment wherein the bone void filler10′ does not include selectively removable portions20a-d, but has substantially the same geometries as prosthesis10. This embodiment may also be constructed from the same materials as that of prosthesis10, including portions of porous metallic material. Further, this embodiment may also be constructed from solid metal or high strength polymeric material. FIGS.7-10depict the interface between the void filling prosthesis10,10′ and a femoral component30. The femoral component30may be any femoral component30, for example a femoral component30utilized in a posterior stabilized or total stabilized total knee prosthesis, for example the Scorpio® TS femoral component (Howmedica Osteonics, Mahwah, NJ). The void filling prosthesis10,10′ may be placed in contact with the femoral component such that aperture18of the central body11is placed over a stem portion of the femoral component30and the inner surfaces15a-dare placed in contact with the cam box33. In one embodiment, bone cement is placed between the inner surfaces15a-dand the cam box33to provide for additional support. Such inner surfaces15a-dmay be stepped to provide more surface area for bonding to the cement. In one embodiment, the distal ends of the legs12,13do not contact the bone contacting surface35of the femoral component in order to provide some space for bone cement to flow and to provide space so that the operator can make minor corrections to the rotation of the femoral component30. A set of guided instruments may be provided to form the bone void to receive the void filling prosthesis. Included in this set of instruments may be an IM reamer40, a boss reamer50, a reamer guide assembly60, an alignment handle90, an alignment pin100, a lobe reamer assembly110, and a lobe trial120. The IM reamer40, as depicted inFIG.11, may include a shaft42that includes a plurality of depth indicators44situated along the length of the shaft42at designated intervals, and a reamer head43disposed at one end of the shaft. The other end of the shaft41may be configured to interface with a torque applying device, such as the chuck of a drill. The boss reamer50, as depicted inFIG.12, may include a cannulated shaft52that includes a boss reamer head53at one end. The other end51of the shaft52may be configured to interface with a torque applying device, such as the chuck of a drill. The internal diameter of the cannulated shaft52is such that the shaft52may be slid over the IM reamer shaft, but generally not the IM reamer head, and rotated with respect to the IM reamer. The boss reamer head may also be cannulated to slide over the IM reamer shaft42and may have a cutting diameter substantially similar to the diameter of the central body11. The reamer guide assembly60, as depicted inFIGS.13-19, may include a trial stem70and a reamer guide80. The reamer guide generally includes a base82, a support shaft81, and a guide block88. The trial stem70may be connected to one end of the base82. In one embodiment, this connection may be a threaded connection, ball-detent connection or any other connection as is known in the art. The other end of the base82includes an abutment surface89and the support shaft81extending from the base82at an outward angle with respect the longitudinal axis of the trial stem70. The support shaft81then bends such that the remainder of the support shaft81is generally parallel to the longitudinal axis of the trial stem70. Integrated into the end of the guide shaft81is the guide block88. The guide block88generally includes a handle hole83extending through the guide block88for receipt of an alignment handle90(described below), an alignment pinhole (not shown) for receipt of an alignment pin100(described below), and a first and second lobe reamer guide84,85. The first and second lobe reamer guides84,85are generally disposed between the handle hole83and alignment pinhole. Both the first and second lobe reamer guides84,85include a passageway86a,86bthat is substantially cylindrical and a side-slot87a,87bextending through the sides of each of the lobe reamer guides84,85into the passageway86a,896b. The longitudinal axes of the passageways86a,86bextend to a location on the abutment surface89. Further, these longitudinal axes may be provided at various angles with respect to the longitudinal axis of the trial stem70in order to ream different bone void dimensions. The alignment handle90, as depicted inFIG.14-19, is generally an elongate shaft with a flange disposed91along its length for abutting against the guide block88. The alignment pin100is preferably a ⅛″ diameter pin with a length long enough to extend beyond the epicondyles when inserted into the guide block88. While ⅛″ diameter is preferred so as to not obstruct the epicondyles from the operator's view, any diameter pin may be used. The lobe reamer assembly110, as depicted inFIGS.15-17and19, includes a lobe reamer head117, a reamer shaft116, a depth stop collar112, and a bushing113. The lobe reamer head117is disposed at one end of the reamer shaft116, while the other end111of the shaft116is configured to interface with a torque applying device. The depth stop collar112is fixed to the reamer shaft116opposite the end of the lobe reamer head117. The reamer shaft116has a diameter small enough to fit through the side-slot87a,87bof the first and second reamer guides84,85. The bushing113is disposed along a portion of the reamer shaft116between the reamer head117and depth stop collar114such that the bushing113can slide back and forth between the reamer head117and depth stop collar112. The bushing113is generally cylindrical and includes a first segment115and second segment114where the second segment114generally has a larger diameter than the first segment115. The diameter of the first segment115may be dimensioned to slide into and fit tightly within the passageway86a,86bof the first and second lobe reamer guides84,85. The lobe trial120, as shown inFIGS.18and19, includes a lobe trial head125and a first shaft segment124and a second shaft segment122. The lobe trial head125dis disposed at the end of the first shaft segment124and generally has a frustoconical shape with a portion removed along its length. The lobe trial head125is dimensioned to substantially match the bone void formed by the reamer head116and to substantially match at least one leg12,13of the void filling prosthesis10. While the lobe trial head125is depicted as having this shape, the lobe trial head125may have any shape depending on the shape of the reamer head116and the legs12,13of the void filling prosthesis10. The first shaft segment124has a diameter less than that of the second shaft segment122and is dimensioned to be capable of passing through the side-slot87a,87bof the first and second lobe reamer guides84,85. The second shaft segment122is dimensioned such that it can tightly fit and slide within the passageway86a,86bof the first and second lobe reamer guides84,85. An impact surface121is formed at the opposite end of the lobe trial120as that of the lobe reamer head125. The impact surface121is a relatively broad and flattened surface so that the operator can impact the lobe trial70in order to seat the lobe trial head125into a bone void. In one embodiment of the present invention, a method for forming a void in bone to receive the void filling prosthesis10, as illustrated byFIGS.11-19. In this embodiment, the instruments, as described above, are utilized. WhileFIGS.11-19and the following description of the method are directed toward the preparation of a bone void within a femur, it is to be understood that this is merely an example. The following method may be utilized to prepare a bone void in any long bone. Referring toFIG.11, the IM reamer40is depicted as reaming along the IM canal of a femur200until the bone200is flush with the requisite depth indicator44. While it appears fromFIG.11that the IM reamer40is passing through a femoral component, the femoral component is merely a depiction of the femur200. With the IM reamer40remaining within the IM canal, the boss reamer50is slid over the shaft of the IM reamer, as shown inFIG.12. The operator reams along the IM reamer shaft42until the boss reamer head53abuts the IM reamer head40, thereby preventing further travel into the femur bone200. The IM reamer and boss reamer50are then removed from the IM canal in preparation for further bone forming. Referring toFIG.13, the reamer guide assembly60is assembled. In such assembly, the operator may select a trial stem70to match the IM reamer head diameter, and then attach the trial stem70to the reamer guide80. In another embodiment, the IM reamer40may be attached to the reamer guide80, thus taking the place of the trial stem70. Attachment may be by a threaded engagement, with a ball detent, or any other engagement known in the art. Once the reamer guide assembly60is assembled, the trial stem70is inserted into the portion of the IM canal that was reamed by the IM reamer40, and the base of the reamer guide82is inserted into the portion of bone reamed by the boss reamer50. The operator may further seat the reamer guide assembly60to the proper depth by impacting the end of the guide block88. The proper depth may be indicated when the reamer guide assembly110no longer moves when impacted and generally where the bone is flush with the bend in the support shaft81. Referring toFIG.14, with the reamer guide assembly60firmly seated within the IM canal, the alignment handle90is placed in the handle hole83until the flange91abuts the guide block88, and the alignment pin100is placed in the alignment pinhole such that the alignment pin100extends from both sides of the guide block88beyond the periphery of the femur. The operator will then grip the alignment handle90and rotate the reamer guide assembly60within the IM canal until the alignment pin100is aligned with the transepicondylar axis or any axis of the operator's preference. Referring toFIG.15, once alignment is achieved the lobe reamer assembly110is loaded into the first lobe reamer guide84. This is achieved by moving the bushing113so that it abuts the depth stop collar112, thereby exposing the reamer shaft116proximate to the reamer head117. The reamer shaft116is then side-loaded through the side-slot87aand into the passageway86a. The resulting configuration should be such that the reamer head116is located on one side of the first lobe reamer guide84and the bushing113located on the other side, as shown inFIG.15. The first segment115of the bushing113is then slid into the passageway86auntil the second segment113abuts the first lobe reamer guide84, as shown inFIG.16. The reamer head116is then advanced into the distal femur by applying a torque to the reamer shaft115until the depth stop collar112abuts the bushing113and the reamer head116abuts the abutment surface82, as shown inFIG.17. The reamer head116is then retracted from the femur and the reamer assembly110removed from the first lobe reamer guide84through the side-slot87a. Referring toFIG.18, the lobe trial120is then loaded into the passageway86aof the first lobe reamer guide84in a similar fashion as the lobe reamer assembly110. The first shaft segment124of the lobe trial120is passed through the side-slot87aand into the passageway86a. The lobe trial head125is then advanced into the first bone void. As the lobe trial head125is advanced, the second shaft segment123is advanced into the passageway86aand the lateral protrusion123is advanced into the side-slot87a. The lateral protrusion123ensures that the lobe trial120has the proper rotational alignment and also acts as a stop to prohibit rotation. In one embodiment of the lobe trial120, the lateral protrusion123may be a pin that extends through the second shaft segment122and into a hole located in the first lobe reamer guide84to prevent both rotational and translational movement. The operator may then impact the impact surface121to fully seat the lobe trial120. The lobe trial120may remain in place while a second bone void is formed in order to provide additional stability during reaming, as seen inFIG.19. Referring toFIG.19, the lobe reamer assembly110is side-loaded into the second lobe reamer guide85as previously described. The reamer head117is then advanced into the distal femur by applying a torque to the reamer shaft116until the depth stop collar112abuts the bushing113and the reamer head117abuts the abutment surface89, thereby forming a second bone void for receipt of the void filling prosthesis10. While this method has generally been described herein as utilizing one lobe reamer assembly120to form both bone voids, more than one lobe reamer assembly110having different geometries may be used depending on the geometry of the void filling prosthesis10. FIGS.20-23depict another embodiment void filling prosthesis210, which is similar to the void filling prosthesis10previously described but differs in that an entire leg may be selectively removed. As shown, void filling prosthesis210includes a central body211, a lateral leg212and medial leg213. Central body211is shown as being generally cylindrical and including an aperture218extending therethrough, like in the void filling prosthesis embodiments previously described herein. The central body211can be made from various materials including titanium, titanium alloy, stainless steel, cobalt chrome alloys, tantalum, or niobium. In addition, these materials may be provided in various forms, such as in a solid or porous form, for example, in the form of metallic foam. In a preferred embodiment, the central body211includes an inner sleeve217(best shown inFIGS.20and23) constructed from a solid material and an outer shell216(best shown inFIGS.21and22) constructed from the same material in porous form to facilitate bony ingrowth. As an example, the inner sleeve217may be constructed from solid titanium and the outer shell216may be constructed from titanium foam. The inner sleeve217is generally the inner support structure for the central body, with the solid construction of the inner sleeve217providing structural support to a porous outer shell216and a bearing surface for an implant stem (not shown). In other embodiments, the central body211can be constructed entirely of one material in one form. For example, the central body211may be constructed entirely of a solid titanium or titanium foam. In another embodiment, the central body211may be constructed from different materials and different forms. For example, the inner sleeve217can be constructed from solid tantalum and the outer shell216can be constructed from titanium foam. Central body211also includes a first end, a second end and an intermediate member214coupled to the second end. In some embodiments, intermediate member214may be a separate structure mechanically coupled to the second end of the central body211, for example via a welded connection or an adhesive. In other embodiments, the intermediate member214may be integrated into the central body211to form a monolithic structure, for example by building both structures together layer-by-layer or molding the structures together as a unitary structure. In either embodiment, the intermediate member214is preferably sized and shaped to conform substantially to the central body211such that there may be a smooth transition between the intermediate member214and central body211. The intermediate member214can be constructed from the same materials and forms as that previously discussed in relation to the central body211. In a preferred embodiment, the intermediate member214is constructed from a porous material that has a porosity larger than that of the outer shell216of the central body211. Generally, the intermediate body's construction is selected to facilitate connection of legs212and213to the central body211and to allow for ease of separation of legs212and213from the central body211when desired. As such, the porous material used in constructing the intermediate member214may include spaces or cells (not shown) that are both large relative to that of the central body's materials and predeterminately arranged in a uniform pattern, rather than randomly distributed throughout the material. This uniform pattern and large porosity relative to that of the central body211may facilitate penetration of a cutting device and provide for a smooth and uniformly cut surface. In one example, the cells of the porous material can be polygonal like that of a honeycomb or like a hollow rectangular prism. Thus, in one embodiment, the intermediate member can be constructed from titanium honeycomb or from titanium arrayed with adjacently situated, hollow rectangular prisms. These polygonal-like cells may provide structural strength while allowing the walls (not shown) making up each cell to be thin to facilitate ease of cutting. In an alternative embodiment, the intermediate member214can be constructed from a metallic material with a lower modulus to that of the central body211and/or lateral and medial legs212,213to facilitate ease of cutting and to help prevent cutting penetration of the central body211and/or the lateral and medial legs212,213. In another embodiment, the intermediate member214may have an identical construction to that of the central body211or be made entirely from metallic foam. The lateral and medial legs212,213have a similar profile to the lateral and medial legs12,13previously described herein in order to conform to predictably shaped bone voids formed by generally cylindrical reamers and to communicate with a femoral component. Each leg212,213is formed by a portion or portions of a support member220(discussed more fully below) covered with a bone interface member230. As best shown inFIGS.21and22, the support member220includes an upper portion222, a middle portion224, a lower portion226, an inner surface228and outer surface229. In some embodiments, the support member220may only include the upper portion222and middle portion224, or may only include the upper portion222. As depicted, the upper portion222and lower portion226join the middle portion224to form a z-like configuration. The upper portion222is semi-cylindrical and has an inner radius similar to the inner radius of the intermediate member214. The middle and lower portion224,226are preferably dimensioned and shaped to conform to the periphery of the bone interface member230. The bone interface member230generally interfaces with the bone when implanted, while the support member220generally communicates with a femoral component when implanted and supports the bone interface member230in a connection with the central body211via the intermediate member214. The support member220includes generally planar inner and outer surface228,229to make way for the femoral component, and the bone interface member includes generally curved surfaces to conform to the bone. In some embodiments, the bone interface member230may be a separate structure mechanically coupled to the inner surface228of the middle and lower portions224,226of the support member220. In other embodiments, the bone interface member230may be integrated into the support member220to form a monolithic structure, for example by building both structures together layer-by-layer or molding the structures together as a unitary structure. The lateral and medial leg212,213can be constructed from any of the materials and forms previously described in relation to the central body211and intermediate member214. In a preferred embodiment, the support member220of each leg is constructed from a solid material and the bone interface member230is constructed from a porous material. As an example, the support member220may be made from solid titanium, and the bone interface member230may be made from titanium foam. In an alternative embodiment, the support member220and bone interface member230may be made from one material in one form. For example, the support member220and bone interface member230may be made entirely from metallic foam. In another embodiment, the support member220and bone interface member230of each leg212,213can be constructed from different materials and different forms. For example, the support member220may be made from solid tantalum while the bone interface member230may be constructed from titanium foam. In yet another embodiment, the lateral and medial leg212,213may be constructed as that previously described in relation to void filling prosthesis10, wherein the lateral and medial legs212,213include selectively removable portions for reducing the length of a select leg. The upper portion222extends outwardly from its respective leg212,213in a cantilevered fashion and is coupled to the intermediate member214at the inner surface228of the upper portion222. Such connection occurs substantially along a plane to facilitate separation between the intermediate member214and the upper portion222, which may result in the removal of a leg. Separation may also be facilitated by a gap215formed between the upper portion222of the lateral leg212and the upper portion222′ of the medial leg213, which allows separation of a single leg to occur by cutting along a single plane. In other words, the lateral leg212and medial leg213may be separate structures attached to the intermediate member214, with a gap215formed therebetween. In certain embodiments, the legs212,213may be formed as a unitary structure in that both legs212,213may be directly connected to each other with no gap being formed. In such a case, where it would be desirable to remove only the lateral leg212or only the medial leg213, separation may be achieved by cutting between the intermediate member214and upper portion222as well as at a location somewhere between the lateral and medial leg212,213in order to remove the leg. On the other hand, where the legs212,213are separate structures forming a gap215, separation may be achieved by cutting only between the intermediate member214and upper portion222. Additionally, gap215may extend into the intermediate member214or bisect the intermediate member214. The extension of the gap215into the intermediate member214or bisection of the intermediate member214by the gap215may allow the operator to cut the intermediate member214along any plane extending through the intermediate member214to the gap215, rather than only along a plane formed by the junction of the intermediate member214and each leg212,213. Generally a lateral or medial leg212,213may be removed through the use of a cutting device, such as that previously discussed herein and disclosed in U.S. application Ser. No. 12/002,002, the disclosure of which is hereby incorporated by reference herein, by cutting in an anterior-posterior direction. In some embodiments the bone interface member230may wrap around a portion of the intermediate member214partially obstructing the intermediate member214anteriorly and/or posteriorly as depicted inFIGS.20and23. In such embodiments, the upper portion222of the support member220may attach to the intermediate member214at locations that are not obstructed by the bone interface member as illustrated inFIGS.21and23, allowing an anterior-posterior cut to be performed along the junction between the intermediate member214and the upper portion222without going through or around the bone interface member230. While the aforementioned description and related figures describe a void filling device having selectively removable legs, it is contemplated that the selectively removable features of the first embodiment10may be combined with selectively removable lateral and medial legs of the present embodiment210providing an operator with the flexibility to reduce the length of a leg or entirely remove a leg. Another aspect of the present disclosure includes methods of filling bone voids. During a knee revision procedure, an operator may remove the previously implanted prostheses. Generally, a central bone void extends into femur and/or tibia, and oftentimes unpredictably shaped bone deformities are formed adjacent to the central bone void by the incidental removal of bone during the implant removal process. Such bone deformities may interfere with the revision prostheses and may be rectified in a number of different ways including reaming the bone deformities to form predictably shaped offset bone voids as previously described herein and/or by removing a section of bone housing the deformity from the proximal tibia or distal femur. Once the bone is shaped to account for bone deformities, the operator may assess the bone to determine the number of offset bone voids for filling with a void filling prosthesis. In some instances where there are less offset bone voids than there are legs associated with a void filling prosthesis210, for example where only a lateral or only a medial offset bone void exists, the operator can remove a lateral or medial leg212,213in order to correspond with the number of voids. Generally, a cutting device, such as that previously discussed herein and disclosed in U.S. application Ser. No. 12/002,002, may be utilized to separate either the lateral or medial leg212,213from the remainder of the void filling prosthesis. A planar blade may be inserted through the junction between the intermediate member214and the upper portion222and between the gap215and bone interface portion30. Alternatively, the planar blade may be inserted through the intermediate portion214between the gap215and bone interface portion230. The leg may be removed by cutting from an anterior and/or posterior direction. As previously mentioned, the intermediate member214is generally constructed of a softer material or a material with a larger porosity than the support member to facilitate visualization of the junction between the two members and to facilitate a smooth and easy cut resulting in a predictable surface. Once the void filling prosthesis210has the desired number of legs, the operator may implant the prosthesis by inserting the central body211into a central bone void and the remaining leg(s) into the offset bone void(s). Alternatively, where the offset bone voids equal the number of legs of the prosthesis as provided, the implant may be implanted without any removal of legs. On the other hand, where there are no offset bone voids, all of the legs may be removed and the central body211and intermediate member214may be inserted into the central bone void. FIGS.24A-27depict alternative void filling prosthesis300. Void filling prosthesis300is similar in certain respects to void filling prostheses10and210. For example, prosthesis300similarly includes a central body302, a first leg304and a second leg306. Alternatively, prosthesis300may include a central body302and only the first leg or second leg304,306. Further, void filling prosthesis300can similarly fill a void formed by the methods previously described herein with relation toFIGS.11-19. However, prosthesis300differs from prostheses10and210with respect to certain features and configurations of the central body and first and second legs. Unlike central bodies11and211, which are depicted as being ring-like or annular shaped such that each have an enclosed or encompassing circumference, central body302is open. This open central body302is defined by an aperture308that extends through the length of the body302and also through a sidewall along the body's entire length, which forms a “C” or “U” shaped cross-sectional profile. As such, central body302includes a curved portion313and a first wall portion315and second wall portion317, which each adjoin the curved portion313at opposite locations. The curved portion313may be semicylindrical such that it has a constant outer and/or inner radius along the length of the central body302. Alternatively, and preferably, the curved portion313has a frustoconical taper such that its outer and/or inner radius differs along its length. In some embodiments, the inner radius may be constant along the length of the body302, while the outer radius may have a frustoconical taper, and thus a varying wall thickness, along the length of the body302. In other embodiments, the central body302can have both a cylindrical portion and a frustoconical portion in a stacked arrangement. The first and second wall portions315,317may have planar inner and outer surfaces such that the cross-sectional profile of the inner and outer surfaces of the central body is U-shaped. In other embodiments, the first and second wall portions315,317may each have a curved outer surface and a planar inner surface which may tangentially intersect an imaginary cylinder or conical frustrum defined by the inner surface of the curved portion313. Thus, in such embodiment, the wall thickness between the inner surface and outer surface of the central body302at the first and second wall portions315,317may vary in order to allow for such planar inner surfaces and curved outer surfaces. The cross-sectional profile of the outer surface body302in such embodiment would be C-shaped, and the cross-sectional profile of the inner surface of the body302would be U-shaped. In another embodiment, the inner and outer surfaces of the body302at the first and second wall portions315,317may be similarly curved such that the cross-sectional profile of the inner and outer surfaces of the body302may be C-shaped. The inner surface of the central body302may have three dimensional features, such as a stepped surfaces, to promote the securement of bone cement or other adhesives thereto. Where such features are included, the inner radius of the curved portion313is determined by the innermost regions of such features. The radius of the curved portion313and the shortest distance between the first and second wall portions315,317may be larger than the cross-sectional thickness of a stem360of a joint prosthesis such as to allow the placement of about at least a 2 mm cement mantle between the stem360and the inner surface of the central body302. The aperture308of the central body302preferably extends through the sidewall in an anterior direction. However, the aperture308may extend through the sidewall in a posterior direction. The combination of the anterior or posterior opening in the sidewall along with dimensioning that allows for the placement of a cement mantle provides for the accommodation of many different size and shape stem components. Additionally, the space provided by the relatively larger dimensioning and the anterior or posterior opening in the sidewall provides operating-room flexibility in that it allows the operator to shift the stem360and joint prosthesis attached thereto in any number of directions so that the operator can more precisely position the articular surface of the joint prosthesis. In particular, the flexibility to shift the stem360in an anterior-posterior direction is beneficial in positioning the articular surface in order to achieve the desired flexion and extension gaps and to achieve the desired patellar tendon tension. Such flexibility also allows the operator to utilize offset stems without having to refit a new void filling prosthesis. Similar to the legs of prosthesis10and210, the first and second legs304,306may be offset posteriorly from a median transverse axis of the central body302. Further, the first and second legs304,306may be located in close proximity, but may be separated generally by a space310that penetrates through both legs and forms a saddle-like structure in order to provide clearance for a femoral cam box of a femoral component. This space310forms inner surfaces320and322that may abut the femoral cam box when implanted. As best shown byFIGS.24A and25, these inner surfaces include flat, planar sections321, and stepped sections323to facilitate bonding with bone cement or other adhesive. Alternatively, these inner surfaces320,322may only be planar and may include a textured surface for cement adhesion, or they may be entirely stepped. Further, inner surface322may be obliquely angled with respect to the longitudinal axis of the central body302in order to account for the angle of the IM stem360with respect to the surfaces of the cam box (not shown). Further geometric features may be incorporated into the first and second legs304,306in order to provide clearance for the structure of the femoral component and to also conform to the resected surfaces of the distal end of a femur bone so as to provide structural support to the bone as close to its outer boundaries as possible. For instance, each leg includes surfaces314,316, and318, where each surface is angled with respect to each other such that, when implanted, such surfaces would be substantially coplanar to a distal, anterior chamfer, and anterior resected surfaces,352,354,356, respectively (best shown inFIG.27). These surfaces314,316,318are angled to coplanarly conform to these resected surfaces352,354,356that are formed in a typical five-cut femur (distal, anterior, posterior, and anterior/posterior chamfer resections). However, each leg304,306could also have surfaces formed to coplanarly conform to a three-cut femur (distal, anterior, and posterior resections). For instance, surfaces318and316may be combined into one surface angled with respect to surface314in order to match the angle of an anterior resection with respect to a distal resection of a three-cut femur. As shown, surfaces316and318are stepped to facilitate cemented fixation with a femoral joint prosthesis. Surface314is planar, but may be stepped and/or include a textured surface to facilitate cement adhesion. In some embodiments, each of these surfaces314,316,318may be planar, or any combination of stepped and planar. Each leg304,306also includes an impaction feature324that is a recess extending longitudinally into each leg304,306from the distal end of each leg. These features are shaped to receive a complementary shaped impaction tool (not shown) that can tightly fit with the impaction feature324and allow the operator to uniformly impact prosthesis300into a void formed in the end of a bone. The remainder of the first and second legs304,306that has not been shaped to receive an impaction tool, conform to a femoral cam box, or conform to resected bone surfaces generally has a frustoconical profile. This geometric profile is preferred in order to conform closely to bone voids created by complimentary frustoconical reaming instrumentation. This frustoconical shape is additionally beneficial in that it allows for easy bone preparation utilizing a frustoconical reamer, and also provides a tapered bone contact surface, which facilitates a very tight press-fit fixation within the target bone. Additionally, the frustoconical profile of each leg can be the same as the frustoconical profile of the central body so that a single reaming device may be utilized to form the bone void to receive prosthesis300. However, frustoconical is merely an example of the type of geometry that the first and second legs304,306may form. The legs304,306may have other geometries, such as box-like geometries. Additionally, the first and second legs304,306may be symmetric with respect to one another for universal fit into both a right and left limb, or they may be asymmetric where one leg304,306may be larger than the other and/or one leg may have a different geometry for a limb specific configuration. Void filling prosthesis300may be constructed from various metallic or polymeric biocompatible materials. For example, prosthesis300can be made from titanium, stainless steel, cobalt-chromium, tantalum, niobium, or polyethylene. Additionally, prosthesis300can have porous outer surfaces326for directly contacting bone to facilitate bony ingrowth into its porous structure. Preferably a portion of prosthesis300is formed from porous material and a portion is formed from solid material. Solid, as used herein, means that the porosity of its structure is unlikely to allow bone ingrowth therein. As best seen inFIGS.24A,24B and26, inner surface312of the central body302and surfaces314-323of the first and second legs304,306are preferably solid, while the outer surfaces326that contact bone when implanted are preferably porous. Further, prosthesis300preferably includes a solid rim328that runs along the outer boundaries of the prosthesis and connects the outer surfaces326with the inner surfaces312and314-323of the prosthesis300. The rim is preferably constructed from a solid material that spans the entire thickness of the prosthesis at the outer boundaries. Such boundaries may occur at intersections between bone contact surfaces and implant interfacing surfaces, that is, surfaces that directly contact or face the joint prosthesis or are connected to the joint prosthesis via adhesive. Other boundaries in which the solid rim may be found occur at the interface329between the central body302and legs304,306. The rim at this interface329may also be formed of solid material, which extends through the entire prosthesis thickness to reduce the risk of fracture at that junction. The solid rim328provides strength and structural support to the porous structure, particularly during impaction, and also helps to significantly reduce or eliminate potential sharp edges that can form where a hard porous structure comprises an outer boundary of an object. In some embodiments, the entire prosthesis300may be porous, or the legs304,306may be entirely porous and the central body302entirely solid. In some embodiments, the outer surface326of prosthesis300may also have discrete sections that are porous and discrete sections that are solid. This may be particularly useful where a patient's bone structure has significantly deteriorated to the point that the bone defects are no longer contained within the cortical bone. In this scenario, prosthesis300can take the place of the deteriorated cortical bone by providing discrete sections of the outer surface, or even entire legs, with solid material to act as cortical bone. The porous and solid portions of prosthesis300may be precisely formed by SLM as described in the heretofore referenced applications incorporated by reference herein, for example, and could even be formed as patient specific in instances where the bone defects are known prior to the surgical procedure. Additionally, prosthesis300may be formed and provided in various sizes in conformance with a database that catalogues the specific anatomy of a selected population of individuals. As previously mentioned, the methods of forming a bone void previously described herein may be utilized in implanting prosthesis300. As such, a frustoconical reamer may form a central void for receipt of the central body302and may form two adjacent and offset frustoconical voids for receipt of the first and second legs304,306. In some scenarios, where a bone defect only exists lateral or medial of the IM axis, a central void and only one offset void may be formed, and a prosthesis with a central body302and only one leg304,306may be implanted therein. Implantation is achieved by connecting an impaction tool to the impaction feature324and using a mallet, or some other blunt instrument, to impact prosthesis300into the formed bone void. Generally impaction is ceased when surfaces314,316,308are coplanar with resected surfaces352,354,356of the bone354. The tapered nature of the frustoconical voids and frustoconical central body302and legs304,306provides a tight press fit such that all or most bone contact surfaces326are firmly pressed against the bone350, which facilitates bony ingrowth into the porous structure. Once prosthesis300is implanted, a joint prosthesis with a stem component360may be implanted. The stem360is inserted through the central body302where the operator has the freedom to adjust the stem360in multiple directions, particularly in an anterior-posterior direction to precisely seat the joint prosthesis onto the bone350. Bone cement, such as polymethyl methacrylate, may be placed between the central body inner surface312and stem360and also along surfaces314-323to join the joint prosthesis with prosthesis300and bone350. Stepped surfaces provided on surfaces316,318, and323and optionally314,321, and322help prevent the separation of cement at the prosthesis-cement interface under loaded conditions. As such, the stepped surfaces are generally formed such that the stepped surfaces taper outwardly in the direction of the loads under normal operating conditions. FIG.28Adepicts another void filling prosthesis400. Void filling prosthesis400is frustoconical shaped and has an aperture403extending through its entire length. Recesses402extend through the sidewall of prosthesis400to provide free space in order to receive a keel of a joint prosthesis, such as a tibial baseplate prosthesis. The outer surface408of the prosthesis is preferably constructed of a porous material while the inner surface404is preferably solid. Additionally, the inner surface404may include a stepped surface to facilitate cement adhesion. The inner surface404generally tapers inwardly from the proximal end410to the distal end412and the stepped surfaces provide resistance to loads at the cement-prosthesis interface. Similar to prosthesis300, a solid rim406is provided around the boundary of prosthesis400to provide strength and reduce the likelihood of sharp edges created by the porous structure, as best shown byFIG.28B. Additionally, the rim406at the proximal end of prosthesis400may have a groove or a channel to receive bone cement or other adhesive in order to facilitate a firm connection between a joint prosthesis and prosthesis400. In an alternative embodiment, void filling prosthesis400may have a similar construction to that of body302of void filling prosthesis300such that the aperture403extends through the sidewall of prosthesis400at an anterior or posterior location. Such embodiment of prosthesis400may also have a curved portion with a similar frustoconical or cylindrical geometry, and a first and second wall portions that have similar planar or curved geometries. In such an embodiment, recesses402may extend through the first and second sidewalls to create space for the receipt of a tibial baseplate keel. This embodiment may be implanted into a tibia bone, while the opening formed in the sidewall by the aperture would allow the operator flexibility in positioning the stem so that a tibial baseplate connected thereto may be properly positioned on the proximal tibial resection. Prosthesis500, as depicted inFIG.29A, is similar to prosthesis400, but differs in that prosthesis500includes a frustoconical lobe504portion for receipt of a keel of a joint prosthesis. Prosthesis400generally includes a body502and a lobe portion504. The body502generally has a frustoconical profile, and the lobe portion504is generally a bump-out of the sidewall of the body502in the shape of a conical frustrum. Additionally, this lobe portion504has a central axis that is obliquely angled with respect to the central axis of the body502. However, in some embodiments, these axes may be parallel. Also, in some embodiments, prosthesis400may include two lobe portions that are symmetrically arranged with body504, which may be beneficial in addressing lateral and medial bone deformities. In some embodiments, one lobe may have a central axis parallel with the central axis of the body502, and the other lobe portion may have a central axis obliquely angled with respect to the body502. In further embodiments, the aperture extending through body502may also extend through the sidewall of the body502at an anterior or posterior location much like that of body302of void filling prosthesis300. Such opening formed in the sidewall would still allow for the lobe portion504and the recess506as the recess506and lobe portion504tend to be located more laterally and medially. This opening would also form a curved portion and a first and second wall portions much like that of body302. However, in such an embodiment, the lobe portion504may be formed out of the first or second wall portion. Thus, in one embodiment, the curved portion could be cylindrical or frustoconical, the first wall portion could be planar or curved and have recess506extending therethrough, and the second wall portion could form lobe504. In some circumstances where two lobe portions are desired, both the first and second wall portions can form the two lobe portions. The lobe portion504may include an indented portion in its inner surface in order to accommodate large keels that extend into the inner surface of the lobe portion to prevent impingement of the prostheses. In some embodiments, as depicted inFIG.29B, this indent may be a void in the inner surface of the lobe504such that the porous outer surface is exposed to the prosthesis aperture. This in and of itself may allow enough space for the prosthesis keel. However, where more space is desired, a cutting tool, such as a modified hole punch, may be utilized to remove the porous structure entirely from the void. Such features add to the universality of the prosthesis so as to reduce the number of resecting instruments and void filling prostheses in the operating room. Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. Moreover, it will also be appreciated that the features described in connection with individual embodiments may be shared with others of the described embodiments.

11857206

DETAILED DESCRIPTION With reference toFIG.1, a surgical guide100is provided. The surgical guide100is configured to be mounted to a patient's tibia bone3and includes a plurality of modules to guide various surgical tools used throughout the osteotomy procedure. The surgical guide100is patient-specific in that it is designed and manufactured according to the specific anatomy of a patient. In this fashion, the surgical guide100can be shaped and configured such that it can fit precisely on a predetermined position on the patient's bone3and be secured thereto to assure proper alignment of guides for various surgical tools. In the present embodiment, the surgical guide100has a body made from 3D printed plastic, although it is appreciated that other biocompatible materials compatible with other custom manufacturing methods are also possible. The body of surgical guide100comprises a bone interface side101for facing the patient's bone3, and an operative side103for facing away from the patient's bone3. In the present embodiment, bone interface side101is configured to be positioned directly on the patient's bone, and comprises a surface having contours complementary is shape to the surface contours of a predetermined area of the patient's bone3. In this configuration, bone interface side101can abut against the patient's bone, and key into a specific position thereon. In the present embodiment, bone interface side101comprises a solid surface, however it is appreciated that other configurations are possible. For example, the surface can be defined by an open lattice, and can comprise edges conforming to the contours of the patient's bone3. Operative side103is provided opposite interface side101and includes a variety of components for interacting with surgical tools, as will be described in more detail hereinafter. In the present embodiment, the body of surgical guide100is subdivided into two separable sections, including a lateral section105for securing relative to a lateral or medial surface of the patient's bone3and an anterior section107for securing relative to an anterior surface of the patient's bone3. It is appreciated, however, that in other embodiments, more or fewer sections are possible to secure relative to different surfaces of the patient's bone3depending on surgical requirements. In the present embodiment, lateral section105and anterior section107are independently securable relative to the patient's bone3. In this fashion, the lateral105or anterior107section can be removed from the patient's bone3when no longer needed, while the other section can remain secured in place. In the present embodiment, lateral105and anterior107sections are secured directly to the patient's bone, however it is appreciated that in some embodiments, only one of the lateral105and anterior107need be affixed directly to the bone. For example, lateral section105can be affixed directly to the bone3, whereas anterior section107can be removably attached to lateral section105such that it is secured relative the patient's bone3without being directly affixed thereto. In the present embodiment, lateral105and anterior107sections comprise bone-conforming plates secured to the patient's bone3via fasteners. The fasteners comprise surgical screws109although it is appreciated that other types of fastening mechanisms are also possible. As mentioned above, the surgical guide100comprises a plurality of modules to guide various surgical tools used throughout the osteotomy procedure. Each module can perform a different function for assisting with various tasks throughout an osteotomy procedure. Some modules can form integral parts of the lateral105and/or anterior107sections secured directly to the patient's bone3, whereas other modules can be independent elements which can be secured to relative to the patient's bone3by attaching to lateral105and/or anterior107sections. Although a particular set of modules will be described in detail hereinafter, it is appreciated that other modules and combinations thereof are possible depending on the requirements of the surgical procedure. Moreover, although some modules are described as performing particular functions, it is appreciated that some modules can perform two or more functions and/or have other advantages or uses not explicitly described herein, but that would be readily understood by a person of skill in the art upon reading the present disclosure. Drilling Module A drilling module113is provided to assist in creating drill holes116in the patient's bone3in preparation for forming a cut therein. The drilling module113comprises a plurality of drill guides115for cooperating with corresponding drill bits to guide a position, depth, and angle thereof to form drill holes in the patient's bone3in a predetermined configuration. In the present embodiment, the drill guides115each comprise a guiding element accessible from the operative side103of surgical guide100. The guiding element comprises a guide barrel120extending from the operative side103of surgical guide100, although it is appreciated that other types of guide elements are also possible. The guide barrel120extends along a lengthwise axis, between a proximal end proximate the bone interface side101of guide100, and a terminal end124on the operative side103of guide100. The guide barrel120comprises sidewalls defining a hollow interior in the form of a guide tunnel122extending through the guide barrel120along the lengthwise axis thereof, and opening on the bone interface side101and operative side103of guide100. The guide tunnels122are sized and shaped to receive a corresponding drill bit therein, allowing the drill bit to slide in and out of barrel120, while sidewalls of barrel120constrain movement of the drill bit to a predetermined depth, position, and orientation relative to the patient's bone. The guide barrels120are positioned and arranged to create drill holes in a predefined pattern to weaken the patient's bone3in preparation for a planar cut. More specifically, the drill guides115are positioned and oriented in a co-planar, parallel arrangement to define parallel drill holes in the patient's bone3in a common plane133. The guide barrels120of drill guides115are sized based on the specific geometry of the patient's bone3, such that the drill holes cover a majority of a cross section of the patient's bone3, while leaving a non-weakened section to eventually form a hinge along which the patient's bone3can be opened. More specifically, the guide barrels120are positioned such that drill holes define a hinge axis9at a border between weakened and non-weakened areas of the patient's bone3in the common plane133. As can be appreciated, hinge axis9can be oriented depending on the type and position of opening to be formed in the patient's bone3as determined according to a preoperative plan, to correct the mechanical axis of the patient's bone3as needed. In the present embodiment, hinge axis9is a straight line, but it is appreciated that other shapes are also possible. Although in the present embodiment the drilling module113is configured to create drill holes in a parallel orientation, it is appreciated that in other embodiments, the drilling module113can be configured such that some or all drill holes do not run parallel to one another. For example, the drill holes can be grouped into two or more arrangements which intersect with one another. Although different groups of drill holes can be guided by the same drilling module113, it is appreciated that in some embodiments, two or more drilling modules113can be provided, for example to create drill holes in different arrangements, to weaken the patient's bone3in different steps/stages, and/or to allow drill bits to be inserted at different angles of approach. Where a plurality of drilling modules113are provided, they can be positioned and/or attached on the same section of the guide100, or can be positioned on different sections of the guide100, for example to drill on different faces of the patient's bone3and/or allow drill bits to be inserted at different orientations, for example to facilitate drilling holes in a position which would otherwise be more difficult to access. Finally, although in the presently described embodiments the drilling module113is configured to guide drill holes in a common plane133, it is appreciated that in other embodiments, the drilling module can be configured to guide drill holes into two or more planes depending on the requirements of the surgical procedure. Cutting Module Still referring toFIG.1, a cutting module117is provided to assist in cutting the patient's bone3. In the present embodiment, the cutting module117comprises an osteotome guide127for guiding a corresponding osteotome to cut the patient's bone3at predetermined position, orientation and depth. The guide127is configured to guide osteotome to create a planar cut in the patient's bone3in the area weakened by the drill holes116formed using the drilling module113. The cutting module117is provided in anterior section107of guide100, and is affixed directly to the patient's bone via fasteners109. It is appreciated, however, that in other embodiments, the cutting module117can be removably attached to the lateral105and/or anterior107sections of the surgical guide100. In the present embodiment, the cutting module117is configured to guide osteotome to create a single planar cut5in the patient's bone3, however it is appreciated that in other embodiment, the guide can be configured to create two or more cuts and/or cuts having a contour or curve. Spreader Module With reference now toFIGS.2A and2B, a spreader module400to assist in spreading the patient's bone3is shown according to an embodiment. In the present embodiment, the spreader module400is configured to open the patient's bone3along a planar cut5formed therein. The planar cut5is opened at an angle about a hinge9, thereby defining an open wedge7in the patient's bone. The spreader module400is configured to operate in cooperation with anchor module119secured to the patient's bone3, but it is appreciated that other configurations are possible. Predrilling Module With reference toFIGS.3A,3B and3C, a predrilling module300ais provided for predrilling holes in the patient's bone3for eventually receiving fasteners to secure a plate or other implant to the patient's bone3. The predrilling module300ais patient-specific in that it is custom made according to the anatomy of the patient's bone3and according to a preoperative plan. In this fashion, the predrilling module300acan be configured to precisely fit on a predetermined position of the patient's bone3to assure proper alignment, and to assist in drilling holes in the patient's bone3in predetermined positions, orientations and depths. In the illustrated embodiment, the predrilling module300acomprises a body302having a bone interface side301and an operative side303. The bone interface side301comprises a bone-contacting surface having contours complementary in shape to the surface contours of the patient's bone3. In this configuration, bone interface side301can abut against the patient's bone3, and key into a specific position thereon. In the present embodiment, bone interface side301comprises a solid surface, however it is appreciated that other configurations are possible. For example, the surface can be defined by an open lattice, and can comprise edges conforming to the contours of the patient's bone3. The operative side303is provided opposite the bone interface side301and comprises a plurality of drill guides307extending therefrom for guiding corresponding drill bits. In the present embodiment, the drill guides307each comprise a guide barrel309extending from the body of the predrilling module303at a predetermined angle along a lengthwise axis and terminating at a terminal end314. The guide barrel309comprises sidewalls defining a hollow interior in the form of a guide tunnel311extending through the guide barrel309along the lengthwise axis thereof and opening on the bone interface side301and operative side303of predrilling module303. The guide tunnels311are sized and shaped to receive a corresponding drill bit therein, allowing the drill bit to slide in and out of barrel309, while sidewalls of barrel309constrain movement of the drill bit to a predetermined depth, position, and orientation relative to the patient's bone3. An abutting member on the drill bit can limit an insertion depth of an operative end of the drill bit into the barrel309as it abuts with terminal end314of guide barrel309. As can be appreciated, in this configuration, the length of barrel309can limit insertion depth of a drill bit and assure the depth of drill holes formed therewith. The plurality of drill guides307are configured to cooperate with a calibrated drill bit having a fixed operative length. The guide barrels309of the drill guides307are sized, positioned and oriented to create drill holes in a predefined pattern for receiving fasteners to secure an implant, such as plate, to the patient's bone3. As will be described in more detail hereinafter, the implant to be secured can be patient-specific and can be designed to be affixed using different types of fasteners. Based on the anatomy of the patient's bone3, a preoperative plan can define a configuration of fasteners, including size, depth, orientation, and position, such that the implant can be affixed optimally. The drill guides307can thus be configured to guide drill bits to form drill holes in preparation for receiving the configuration of fasteners defined in the preoperative plan. For example, the length of each guide barrel309can be adjusted to limit the insertion depth of the drill bit, creating drill holes with different predetermined depths. Similarly, the position an orientation of guide barrels309can be adjusted to define drill holes which extend at different angles and positions. Finally, diameters of guide tunnels311can be adjusted to accommodate drill bits of different diameters to create drill holes of different sized for accommodating different sizes of fasteners. The module300ais configured to drill holes after the geometry of the patient's bone3has been surgically altered. In this embodiment, the predrilling module300ais configured to span across opening7formed in the patient's bone3, and position drill guides307to define drill holes directly in their final position. More specifically, the predrilling module300ahas a body302substantially similar to a fixation plate which will ultimately be used to secure the opening7in the patient's bone3. The bone3can thus be opened along planar cut5to form opening7, and once the opening7is formed, the predrilling module300can be secured to the bone at the same position where the fixation plate will eventually be attached. The predrilling module300will thus have its drill guides307positioned exactly where the fastener apertures of fixation plate will eventually be positioned. Therefore, after drill holes are formed, predrilling module300can be removed and replaced with fixation plate. Fixation plate can be positioned to align with the holes and then secured in place via fasteners. As can be appreciated, the required position of drill holes can be determined by modelling the patient's bone3, virtually opening the bone model to a desired opening angle, and virtually positioning an implant and corresponding fasteners on the bone model to set final positions of the drill holes. In the present embodiment, the body302of predrilling module300has a bone interface side301having a bone-contacting surface substantially conforming to a surface contour of the patient's bone3at a predetermined position. The body302is configured with a proximal section302afor positioning adjacent a surface of the patient's bone3above opening7, a distal section302bfor positioning adjacent a surface of the patient's bone3below opening7, and an intermediate section302cfor spanning the opening7. The attachment/alignment mechanism305comprises a wedge extending from bone interface side301on the intermediate section302cof body302, and configured to be inserted into the opening7. As can be appreciated, wedge305can be sized and shaped according to the expected dimensions of the desired opening7according to a preoperative plan. It can further comprise contours matching inner surface contours of the opening7, as will be described in more detail below in connection with the opening validator. The wedge305can thus allow predrilling module300to secure at a predetermined position relative to opening7, while also validating that the bone3has been opened to the correct angle. Once module300has been correctly positioned, it can be secured in place relative to the patient's bone3before drilling is performed through drill guides307. In the present embodiment, the body302comprises fastener apertures312a,312bin the proximal302aand distal302bsections to allow the body302to be secured directly to the patient's bone3via fasteners. It is appreciated, however, that other attachment mechanism are possible. For example, the module300could secure to an anchor module already attached to the patient's bone3at the correct position. Opening Validator With reference now toFIGS.3C,4A and4B, an opening validator500for validating the open wedge7formed in the patient's bone3is shown according to an embodiment. As can be appreciated, a desired opening angle of open wedge7can be predetermined according to a preoperative plan. Although the gauge in spreader module400can provide an indication of the opening angle during the procedure, opening validator500can provide a more precise confirmation as to whether the patient's bone3has been opened the right amount to attain the desired angle of open wedge7. Accordingly, opening validator500is provided to directly measure the open wedge7formed in the patient's bone3. In the present embodiment, opening validator500is a patient-specific tool designed to match the anatomy of the patient's bone3. More specifically, the opening validator500is shaped and configured to fit snugly in the opening7in the patient's bone3based on the expected shape thereof as determined according to a preoperative plan. During the surgical procedure, as the patient's bone3is being spread to form opening7, the opening validator500can be inserted into the opening7. A snug fit of opening validator500can confirm that the correct opening7has been formed, whereas an incorrect fit can indicate that an adjustment of opening7is necessary. It is appreciated that other mechanisms for validating the opening are also possible. As shown inFIG.4A, the opening validator500comprises a unitary body501, made from a rigid, biocompatible material. In the present embodiment, the body501is made from a 3D printed plastic, although it is appreciated that other materials are possible, and that the validator500can be made using other custom manufacturing processes. The body501includes a handle end503and an operative end505. Handle end503is configured to facilitate manipulation of opening validator500during the surgical procedure. In the illustrated embodiment, handle end503comprises a handle507to allow the validator500to be easily grasped and/or manipulated by hand. It is appreciated, however, that other interfaces for manipulating the validator500are also possible. In the present embodiment, the handle507has a substantially rectangular-shaped profile, including an anterior side509aand a lateral side509b. The anterior509aand lateral509bare marked to indicate proper orientation during the surgical procedure. It is appreciated, however, that other shapes of handle507are also possible. Operative end505is configured to engage with the opening7formed in the patient's bone3at a predetermined position and orientation. More specifically, the operative end505comprises a wedge element511sized and shaped to fit in the opening7, and a tab element515to limit the insertion depth of wedge511. Wedge element511is shaped to conform to the contour of interior surfaces5a,5bof the patient's bone3formed by planar cut5and confirm the height of opening7proximate the exterior surface of bone3, and thus confirm opening angle7a. More specifically, wedge elements511comprises a top surface513ashaped to conform to the contour of top or proximal interior surface5a, and a bottom surface513bshaped to conform to the contour of bottom or distal interior surface5b. Similarly, tab element515is shaped to conform to the exterior contours of the patient's bone3. More specifically, tab element515comprises a top surface517ashaped to conform to the exterior contour of the patient's bone3above the cut5, and a bottom surface517bshaped to conform to the exterior contour of the patient's bone3below the cut5. As show inFIG.4B, when opening7in the patient's bone3is opened to the right angle, and when validator500is correctly positioned therein, top513aand bottom513bsurfaces of wedge element511, and top517aand bottom517bsurfaces of tab element515will simultaneously conform and engage with the corresponding surfaces of the patient's bone3, thereby locking opening validator500in place and confirming that configuration of opening7matches the preoperative plan. Any mismatch between the surfaces of the validator500elements and the surfaces of the patient's bone3can indicate that ad adjustment is required. As can be appreciated, opening validator500can be used to assure that opening7in patient's bone3is formed correctly prior to proceeding with subsequent steps of the procedure. For example, it can confirm opening7prior to attaching a fixation plate to secure and retain opening. As another example, as illustrated inFIGS.3A and3B, the opening validator500can confirm opening7prior to attaching predrilling module300a, and thus help position the same, such that fastener holes can be drilled in the patient's bone3after opening7has been formed. Fixation Plate With reference now toFIGS.5A and5B, a fixation plate600is shown. Fixation plate600comprises a body601made from a rigid, biocompatible and degradation-resistant material, such as stainless steel or titanium, although it is appreciated that other materials are possible, including different metals and/or plastics and/or a combination thereof. In the present embodiment, fixation plate600is an osteotomy plate for securing to an antero-medial side of the patient's bone3and retaining the opening7formed therein during an open-wedge osteotomy procedure. It is appreciated that in other embodiments, fixation plate600can be configured for securing to another side of the patient's bone3depending on surgical requirements. In the present embodiment, body601comprises a proximal section601afor securing to the patient's bone3above opening7, a distal section601bfor securing to the patient's bone3below opening7, and an intermediate section601cfor spanning the opening7. As will be described in more detail hereinafter, the present fixation plate600is patient-specific in that it has been designed based on the specific anatomy of the patient's bone3and based on the specific needs of the patient determined during a preoperative plan. The shape and configuration of fixation plate600can therefore vary from one procedure to another based upon the bone anatomy of different patients and based on their different needs. The body601of fixation plate600is sized, shaped, and configured to fit snugly on the patient's bone3while also providing the required support and being minimally noticeable under the patient's skin. In the present embodiment, body601is thin and substantially flat, and is configured to follow the contours of the patient's bone3. In this configuration, for example, when the fixation plate600is secured to the patient's bone3, it can protrude from the surface of the patient's bone3at a uniform height along the entire body601. Moreover, in some embodiments, body601can be designed to have a thickness which varies in different locations, allowing body601to have increased or reduced strength or rigidity where required and/or allow body601to protrude less noticeably from the patient's bone at certain areas. The body601of fixation plate600comprises a bone interface side603and an outward-facing side605. Bone interface side603comprises an inner surface for positioning adjacent the patient's bone3. The contours of inner surface of bone interface side603are complementary in shape to surface contours of a predetermined position on the patient's bone3. In this fashion, fixation plate600can fit snugly on a position of the patient's bone3determined preoperatively. Outward-facing side605is substantially smooth and/or flat to make it minimally noticeable under the patient's skin. In the present embodiment, the outward-facing side605comprises sloped and/or chamfered edges607which provide a smoother transition between the body601of fixation plate600and the patient's bone3. The fixation plate600is secured to the patient's bone3via fasteners609. In the present embodiment, fasteners609comprise surgical screws which are drilled into the patient's bone3, although it is appreciated that other type of fasteners are possible. The fasteners609engage with plate600via apertures or canals610opening on the bone interface side603and the outward facing side605of the plate600. As can be appreciated, canals610can be sized and shaped to receive different sizes of fasteners609. Moreover, canals610can be configured to guide fastener609at a predetermined angle or orientation as it is inserted into the patient's bone3. For example, in the present embodiment, canals610comprise sidewalls extending through the thickness of the body601of plate600at a predetermined angle to guide the fasteners609as they are drilled through the canals610. In some embodiments, the sidewalls of canals610can be threaded, for example to engage with corresponding threads of fasteners609as the fasteners609are being drill through canals610, and/or to engage or lock with a head of the fasteners609once fully inserted. The sidewalls of canals610can further be configured to abut against a head of fastener609to block the fastener609from being inserted too deep into the patient's bone3. As can be appreciated, based on a preoperative plan, fixation plate600can be designed with a different number and configuration of canals610for receiving a different number and configuration of fasteners609based on the specific needs of the patient to promote optimal securing of the plate600. Moreover, the fixation plate600can be configured such that it can accommodate combinations of different sizes of fasteners609(both diameter and length) and different orientation of fasteners609, for example based on the position of the patient's bone3to which a particular fastener609is to be secured. In the illustrated embodiment, the plate600is configured to accommodate two large laterally-spaced fasteners609in the proximal section of body601a, and two smaller vertically-spaced fasteners609in the distal section of body601b. While the above description provides examples of the embodiments, it will be appreciated that some features and/or functions of the described embodiments are susceptible to modification without departing from the spirit and principles of operation of the described embodiments. Accordingly, what has been described above has been intended to be illustrative and non-limiting and it will be understood by persons skilled in the art that other variants and modifications may be made without departing from the scope of the invention as defined in the claims appended hereto.

11857207

DETAILED DESCRIPTION This description of the exemplary embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. In the description, relative terms such as “lower,” “upper,” “horizontal,” “vertical,”, “above,” “below,” “up,” “down,” “top” and “bottom” as well as derivative thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description and do not require that the apparatus be constructed or operated in a particular orientation. Terms concerning attachments, coupling and the like, such as “connected” and “interconnected,” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. This disclosure describes an external fixation apparatus for the foot and tibia, providing ankle joint stabilization, simulated weight bearing, and internal and external foot rotation. The fixation apparatus stabilizes the ankle and restores joint space. The simulated weight bearing feature places the foot bones in position (while in the fixation apparatus) similar to the weight-bearing positions of the bones. The foot rotation function allows rotation of the foot in a transverse plane relative to the tibia after the foot and tibia are fixed by the fixation apparatus. The foot can be rotated after fixation, to establish the mortise view for evaluation. While a patient's foot is fixed in the apparatus, a resection guide cartridge holder is attached to the fixation apparatus. The cartridge holder is configured to align and fix a resection guide or a sizing guide to the foot holder to prepare the tibia and talus for receiving a total ankle prosthesis. If the cut surface of the talus has a void that is to be treated by implantation of a talar plate with an augment, an augment reamer base is pinned to the talus. The reamer base positions and aligns a reamer for enlarging the void to a predetermined size and shape for receiving the augment of the talar plate. The total ankle replacement is implanted while the apparatus fixes the tibia and foot. Fixation Apparatus In total ankle revision procedures the ankle joint can become severely destabilized from incompetent ligaments, bone removal, and/or implant removal. A destabilized joint can be extremely difficult for the surgeon to work with, for example, when aligning the bones and placing the implant in vivo. A fixation apparatus described herein gives the surgeon the ability to restore joint space, tension the ligaments, and stabilize the joint. FIGS.6,7,17and18are isometric views of the fixation apparatus100. The apparatus100comprises a base102. A foot plate assembly200is attached to the base102. The foot plate assembly200has a plurality of members300attached to a foot plate202. The members300are configured for receiving at least a first wire or pin240to fix a foot of a person relative to the foot plate202, while the foot plate202is oriented normal to a superior-inferior direction of the foot in “simulated weight bearing”. FIGS.1-16show components and sub-assemblies of the fixation apparatus100, which are shown isolated or in partially assembled configurations, for ease of viewing. The various components can be assembled in a variety of sequences. The assembly sequence is not limited to the order shown inFIGS.1-16. FIG.1is an isometric view of the base102with the joint stabilization assembly104attached to the base102. The joint stabilization assembly104includes a support (e.g., a tray)106shaped to receive a calf of a person, and a positioning assembly108for attaching the tray106to the base102. The positioning assembly108is coupled to brackets118via the lock knob124(and the stop126attached to the lock knob124). The brackets118are in turn connected to the base102using bolts or screws. In some embodiments, the base102is configured to provide a minimal frame for attachment of the joint stabilizer assembly104, an Achilles support130, the foot plate assembly200, and the struts300. The base102has open spaces to avoid any unnecessary restrictions on access to the patient's limb and the components of the fixture by the surgeon. The support106is generally U-shaped, to comfortably support the posterior side of the calf of the patient. The support106has a medial wall and a lateral wall. The medial and lateral walls of support106are configured for attachment of a wire or pin244(FIG.18) to fix a tibia250of the person in the superior-inferior direction relative to the support106. For example, in some embodiments, the medial and lateral walls of the support106have a plurality of openings107. A wire or pin244is passed through openings107and through the patient's tibia, while the patient's calf is resting on the support106, fixing the tibia in the superior-inferior direction and the anterior-posterior direction relative to the support106. In some embodiments, the positioning assembly108includes a first mechanism112,114,116, such as a gear mechanism, for positioning the support106in a superior-inferior direction relative to the base102. In some embodiments, the support106has a rack116attached thereto, and the first mechanism includes a pinion114for translating the rack116. In other embodiments (not shown), the first mechanism can include a gearing mechanism, a worm drive, a screw mechanism, a rail slidable within a channel, or the like. In some embodiments, the positioning assembly104further comprises a lock110configured to fix a position of the rack116in the superior-inferior direction. For example, the lock110can include a threaded member (not shown) attached to a knob, such that the end of the threaded member bears against the rack116when the knob is turned to advance the threaded member. In some embodiments, the positioning assembly108includes a second mechanism122,124,126for positioning the support in an anterior-posterior direction perpendicular to the superior-inferior direction. For example, in some embodiments, the second mechanism includes a body122attached to the pinion114. The body122has a longitudinal slot. The body122is manually slidable within a channel120fixed relative to the base102. A lock knob124is turned to advance a stop126to apply a bearing force against the body122(or turned in the opposite direction to retract the stop126and release the body122). In other embodiments (not shown), a gear mechanism is used to precisely position the body122in the anterior-posterior direction. The channel120has a longitudinal axis121oriented in an anterior-posterior direction perpendicular to the superior-inferior direction. In some embodiments, the channel120is formed by a groove in a respective bracket118on each side of the body122. In other embodiments (not shown), the body122has grooves or channels on its medial and lateral edges, and the brackets118have rails that are slidably received by the grooves or channels. FIG.2shows the assembly ofFIG.1, to which the Achilles support130is added. In some embodiments, the Achilles support130has a pair of adjustable side brackets132. For example, the Achilles support130can have a track130t which receives a rail132ron the bottom of each side bracket132. The rails132r are slidable within the track130tfor continuously adjusting the distance between the side brackets132. The combination of the Achilles support130and the two side brackets132form a U-shaped support for the lower portion of the leg, between the calf and the foot. In some embodiments, the Achilles support130is attached to a positioning bracket134. The bracket134has an anterior-posterior slot. An adjustment knob136is attached to a threaded member, which passes through the slot and is received by a female thread in the Achilles support130. The anterior-posterior position of the Achilles support130is adjustable by turning the knob136to loosen the Achilles support130, manually adjusting the anterior-posterior position, and tightening the knob136. FIG.3is an isometric view showing a pair of plates140assembled to the base102ofFIG.2. The plates140are attached to medial and lateral sides of a U-shaped bracket146. The plates140are oriented so as to lie in respective parasagittal planes. The U-shaped bracket146is attached to the base plate102by two U-bracket knobs147(FIG.6) on the posterior side of base102, to allow manual adjustments without tools. The plates140include respective inferior slots142and posterior slots144for attachment of a base plate assembly150, discussed below. Both the base plate102and the U-shaped bracket146have a central opening103. The central opening103permits the surgeon to access the ankle from the posterior side during surgery. In some embodiments, the inferior slots142and posterior slots144are curved, to permit the base plate assembly150to rotate about a medial-lateral axis143. FIG.4is an isometric view of the base plate assembly150as seen from the superior side, andFIG.5is an isometric view of the base plate assembly150as seen from the inferior side. The base plate assembly150is configured for holding a foot plate assembly200(discussed below), while permitting rotation of the foot plate assembly200about the superior-inferior axis165, translation of the port172and172ain medial-lateral and anterior-posterior directions relative to the foot plate assembly, and rotation of the base plate assembly150about the medial-lateral axis143(FIG.3). The base plate assembly150has two side plates152, which can be generally L-shaped. The side plates152are attached to medial and lateral sides of a rotation base plate (inferior plate)173. The side plates152have outwardly-extending pins154that are slidably received in the slots144of the plates140. A flexion knob141(FIG.17) comprises a knob attached to a threaded member, which is inserted through the inferior slot142. Turning the flexion knob141advances its threaded member to lock the angular position of the base plate assembly150about the medial-lateral axis143. As shown inFIG.5, the base plate assembly150has an anterior-posterior adjustment plate171attached to the inferior side of the rotation base plate173. In some embodiments, the rotation base plate173has a pair of grooves173gon the inferior side thereof. The grooves173gextend in the anterior-posterior direction. The anterior-posterior adjustment plate171has corresponding ridges171rslidably received in the grooves173g, allowing continuous anterior-posterior adjustment of the port172. The anterior-posterior adjustment plate171has a slot174permitting anterior-posterior motion, and a lock knob176. Advancing the knob176locks the anterior-posterior position of plate171. For example, the knob176can have a threaded member (not shown) that is received by the rotation base plate173, and a washer that bears against the plate171when the knob176is advanced. The anterior-posterior adjustment plate171has a pair of medial-lateral sleeves171A,171B. The medial-lateral sleeves171A,171B are located along a medial-lateral axis of the anterior-posterior adjustment plate171. The medial-lateral sleeves171A,171B are adapted to receive a pair of medial-lateral alignment members or rods260,262(FIGS.17,18). A medial-lateral adjustment plate170is adjustably attached to the inferior side of the anterior-posterior adjustment plate171. In some embodiments, the anterior-posterior adjustment plate171has two channels or grooves171c(e.g., on the anterior and posterior sides thereof); the medial-lateral adjustment plate170has two ridges or rails170rthat are received by the respective channels or grooves171c. This allows the medial-lateral adjustment plate170to slide in the medial-lateral direction relative to the plate171. The medial-lateral adjustment plate170has a slot178permitting medial-lateral motion, and a lock knob179. Advancing the knob179locks the medial-lateral position of plate170. For example, the knob179can have a threaded member (not shown) that is received by the anterior-posterior adjustment plate171, and a washer that bears against the plate170when the knob179is advanced. In some embodiments, the anterior-posterior adjustment plate171and the medial- lateral adjustment plate170have a port172extending therethrough, permitting the surgeon to insert a cannula and trocar (or other surgical tool) into the calcaneus from the inferior side of the apparatus100. The anterior-posterior adjustment plate171and medial-lateral adjustment plate170allow the surgeon to position the port172relative to the axis of the foot plate assembly200. In some embodiments, the medial-lateral adjustment plate170has a sleeve or socket168and an opening or cutout169aligned with each other along the anterior-posterior axis of the medial-lateral adjustment plate170. The sleeve168and opening or cutout169are adapted to receive a pair of anterior-posterior alignment members or rods161,163(FIG.17). In other embodiments (not shown), two sleeves168can be substituted for the single sleeve168and the opening or cutout169. As shown inFIGS.4and6, the rotation base plate173has a retaining body162, such as a mounting ring164, for rotatably mounting the foot plate assembly200(FIGS.8-16). The ring164has an outside surface with a groove166therein. FIGS.8-16show the foot rotation plate assembly200. The base102has a rotation plate173with a circular retaining body162, such as ring164, and the foot plate202has a circular opening209adapted to receive the retaining body162. In some embodiments, the retaining body162includes a ring164with a groove166on a side edge thereof, and the foot plate202has at least one locking pin210that is positionable within the groove166to prevent translation of the foot plate202relative to the retaining body162, but permit rotation of the foot plate relative to the retaining body. In some embodiments, a position of the rotation plate173is adjustable in the anterior-posterior direction relative to the base102. As shown inFIGS.8-10, the assembly200has a plate202. The plate202has a circular opening209configured to be mounted around the ring164of the rotation base plate173. A pair of screws210having bosses212on the ends thereof are threadably received in the medial and lateral side edges of the foot plate202. The bosses212are adapted to engage the groove166on the outside surface of the mounting ring164when the screws210are advanced (e.g., by turning the screws210with a suitable wrench199). Loose engagement between the bosses212and the groove166holds the foot plate assembly200on the mounting ring164, while permitting the foot plate assembly200to rotate around an axis207(FIG.8). Tightening the screws210locks the rotation angle of the foot plate assembly200relative to the base102. The foot plate202is configured to have its axis of rotation207aligned with the tibia250while the foot plate is attached to the base102and the tibia250is secured to the support106. This is a non-limiting example. In other embodiments, a different mechanism is used to pivotally mount the foot plate202to the rotation base plate173. For example, in some embodiments (not shown), the foot plate has a ring, and the rotation base plate has an opening that receives the ring. In other embodiments, the rotation base plate has a ball head permitting the foot plate to pivot and/or rotate. In some embodiments, as shown inFIGS.8-12,15and16, a detachable heel support208is inserted in the foot plate202while the foot is being fixed to the foot plate. The heel support208has an outer edge208ewith a groove matching the groove166on the outer edge of the mounting ring164. FIG.10is a cross-sectional view of the foot plate202, while the detachable heel support208is in place. InFIG.10, one boss212engages the outside edge208eof the heel support208, while the other screw210is still retracted. A cross-sectional view of the foot plate202while the foot plate is attached to the mounting ring164of the fixation apparatus100would look similar toFIG.10, except that inFIG.10, the heel support208is a solid disk, but the mounting ring164is a hollow cylindrical shell when viewed in cross-section. Simulated Weight Bearing When surgeons assess alignment and orientation of bone in the clinical setting they may wish to view weight bearing x-rays. The bones of the foot shift position depending on whether the ankle is weight bearing or non-weight bearing. The degree of joint degeneration and evaluation of the ankle mortise can be underestimated when x-ray is performed on non-weight bearing ankles. Furthermore an accurate measurement of the extent of cartilage involvement and a more dynamic picture of the status of the ankle and hindfoot is achieved in weight bearing x-rays. Thus, the ability to simulate the bone positions of a weight bearing foot provides valuable information to the surgeon. Some embodiments comprise a plurality of independently positionable members300for retaining wires or pins240, and for urging the first wire or pin240in an inferior and/or anterior direction relative to the foot plate202. In some embodiments, the members300are struts as shown inFIG.13A. The plate202includes two strut mounting channels204,206. The channels204,206are configured to receive the members (struts)300shown inFIGS.11-14.FIG.11shows one of the struts300prior to inserting the strut in the foot plate202.FIG.12shows two of the struts300after insertion into the channels206of foot plate200.FIG.13Ais a cross-sectional view of the strut300mounted in one of the channels206. The plurality of struts300each include a threaded member302. The threaded member302has a head304configured to slide along a respective anterior-posterior track206tin the foot plate. The width of the track206tis smaller than the diameter of the entrance204. In some embodiments, the head304has two flat sides304fsized to fit the track206t. Once the head304is moved from the channel entrance204to the track206t, the head304and the threaded member302are prevented from rotating.FIG.14shows the proper rotational position of the strut300for insertion into the channel entrance204, with the flat sides304fof the head304of the strut300parallel to the anterior-posterior track206tof the plate202. The strut300has a lock306for fixing the location of the strut along the track206tthereof. For example, the lock306can be a threaded nut that is advanced against the top surface of the plate to grip the plate.FIG.12shows the plate202after the two struts300are inserted in the tracks206and the locks306are tightened to fix each of the struts in the anterior- posterior direction. The strut300has a guide308for receiving the wire or pin240. In some embodiments, the guide308is not threaded, and is slidable along the threaded member302of the strut300for controlling a position of the wire or pin240in the superior-inferior direction. In some embodiments, the guide308has an eyelet309for receiving the wire or pin240. When the guide308is aligned in the anterior posterior direction, a wire240extending in the medial lateral direction can be passed through the eyelet309(as shown inFIG.18). Movement of the guide308in the inferior direction causes compression of the bones of the mid-foot against the foot plate202, simulating a weight-bearing condition. A compression knob310is provided for advancing the guide308in the inferior direction. For example, the compression knob310can be a threaded nut for urging the guide308(and the wire or pin240passing through the eyelet of the guide308) in the inferior direction toward the foot plate202. In some embodiments, the strut300further comprises a retaining nut312, to prevent any of the components306,308or310from separating from the threaded member302. FIGS.14A-14Cshow an alternative design of a compression member1400according to some embodiments. The compression member (or strut)1400can be substituted for the strut300without any change to the footplate202. The compression member1400has a treaded member1402with a head1422. The head1422can have the same shape and function as the head304described above. A compression nut1420is provided for gripping the foot plate202between the compression nut1420and the head1422, as described above with respect to the lock306of strut300. An alignment member1410holds a pin or wire (not shown), which passes through the alignment opening1412. A compression knob1404is turned to advance the alignment member in the inferior direction, to compress the foot in the simulated weight bearing position. The compression knob1404has a relatively large head1406to be gripped by hand, an inferior ring1408, and a neck1409between the head1406and ring1408for receiving the alignment member1410. The alignment member1410is placed around the neck1409, and a dowel pin1414is inserted through the alignment member1410. The neck1409of the compression nut1420is held between the alignment member1410and the dowel pin1414, allowing the alignment member to be advanced in the inferior direction or moved in the superior direction without rotating the alignment member1410around the compression member1400. The strut1400also allows compressing or tensioning the bones of the mid-foot. In some embodiments, the foot plate202has a pair of heel brackets220that are continuously adjustable in the medial-lateral direction for supporting the medial and lateral sides of the heel. For example, the heel brackets220can each have a medial-lateral slot. A respective screw is inserted through the slot, and attaches each heel brackets220to the plate202. In some embodiments, the heel brackets220include apertures221to permit insertion of wires or pins242through the brackets220and into the calcaneus. Sleeves231can be inserted into the apertures221to guide the wires or pins242. The surgeon can select an appropriately sized sleeve231to accommodate a wire or pin of the size the surgeon intends to use. In some embodiments, as shown inFIGS.15and16, a pair of forefoot brackets230are mounted to slots231in the foot plate202for providing additional support to the medial and lateral sides of the foot. In various embodiments, the slots231can include one or more medial-lateral slots and/or one or more anterior-posterior slots. The brackets230can be positioned along any of the slots231by tightening a knob (not shown) on the inferior side of the foot plate202, to grip the foot plate202. FIG.16shows the foot fixated by the foot plate202, prior to attachment of the foot plate assembly200to the foot holder100. The patient's foot is placed at the center of the foot plate assembly200so the heel is directly over the heel support208. The heel brackets220are adjusted to enclose and support the heel. The forefoot brackets230are adjusted to secure the forefoot. The calcaneus is pinned by the wires or pins242, which pass through the collars of the heel brackets220. The struts300are positioned along their respective channels206(without tightening the locks306), so that a wire or pin240can be placed transversely across the midfoot bones. The wire or pin240is driven through the eyelets309of the guides308and the midfoot bones as shown. The struts300are then locked in position against the foot plate200by rotating the locks306to advance the locks306against the top surface of the plate202. The wire or pin240is cut (e.g., with a pin cutter) or bent, and the compression knobs310are rotated to drive the guides308in the inferior direction toward the plate202and compress the midfoot to the foot plate202, thereby positioning the bones to simulate their weight bearing state. The screws210are retracted to release the heel support208, and the heel support is removed. The foot plate202is now ready for attachment to the foot holder100. To attach the foot plate assembly200to the rotation base plate173of the foot holder100, the ring164of the rotation base plate173is aligned to the hole209in the foot plate202(from which the heel support208has now been removed). Using the appropriate tool (e.g., hex key199ofFIG.8), the screws210are advanced sufficiently to loosely engage the groove166on the outside of the ring164, so that the foot plate assembly200is held by the ring164of the foot plate holder100, but can be rotated around an axis165at the center of the ring164. FIGS.17and18show the complete fixation apparatus100, with the patient's tibia and foot bones included for reference. Skin and soft tissue are omitted from the drawings, but the position of the bones shown in the figures are the positions the bones would occupy if the skin and soft tissues are present. As shown inFIGS.17and18, the foot plate202is attached to the base102. The foot plate202has a plurality of members300attached thereto. The members300are configured for receiving at least a first wire or pin240to fix a foot of a person relative to the foot plate202, while the foot plate202is oriented normal to a superior-inferior direction of the foot. The foot plate202is rotatable relative to the base102while the foot plate202is attached to the base102. A joint stabilizing assembly104is attached to the base102. The assembly104includes a support106shaped to receive a calf of a person, and a positioning assembly108for attaching the support106to the base102. The support106is adapted to receive a wire or pin244for securing the tibia250of the patient. The positioning assembly108includes a first mechanism112,114,116for positioning the support106in a superior-inferior direction relative to the base102. The foot positioning apparatus ofFIGS.17and18is suitable for fixation during a procedure for implanting a full ankle implant700(FIG.38) comprising a talar component704-705configured to be attached to a talus272of the person while the foot is fixed relative to the foot plate202, and a tibial component701-703configured to be attached to a tibia250of the person while the calf is received by the support106, where the tibial component701-703is configured for articulating motion relative to the talar component704-705. In other embodiments, the implant or portion thereof can be inserted outside of the apparatus after its position is determined. In some embodiments, as shown inFIG.17, a pair of anterior-posterior alignment members261,263are received by the sleeve168and the cutout or opening169of the medial-lateral adjustment plate170. The anterior-posterior alignment members261,263extend in the superior direction from the medial-lateral adjustment plate170. InFIG.17, only the finger263A at the superior end of the anterior-posterior alignment member263is visible, and the alignment fingers261A of anterior-posterior alignment member261is hidden behind side plate152. In some embodiments, the anterior-posterior alignment members261,263are both attached to a bar265for ease of handling. The anterior-posterior alignment members261,263have alignment features261A,263A, respectively. In some embodiments, the alignment features261A include two fingers extending in the superior direction on medial and lateral sides of the tip of anterior-posterior alignment member261. The alignment feature263A include a single finger extending in the superior direction at the center of the tip of anterior-posterior alignment member263. As shown inFIG.19, when the anterior-posterior alignment members261,263and the central axis of the tibia are aligned and viewed by fluoroscopy, the finger263A is centered between the fingers261A, and aligned with the tibia250. Conversely, when the anterior-posterior alignment members261,263and the central axis of the tibia are not all aligned, the finger263A is not centered between the fingers261A, and may not be aligned with the tibia250. For example, as shown inFIG.20, the finger263A may be hidden by one of the fingers261A, and neither of the medial-lateral alignment members261,263is aligned with the central axis of the tibia250. Referring again toFIGS.17and18, a pair of medial-lateral alignment members260,262are inserted through the medial-lateral sleeves171A,171B of the anterior-posterior adjustment plate171. The medial-lateral alignment members260,262are positioned to extend in the superior direction from the anterior-posterior adjustment plate171. The medial-lateral alignment members260,262are each positioned with the same displacement in the anterior direction from the center of the opening209of the foot plate202. In some embodiments, the medial-lateral alignment members260,262have respective alignment features that are the same as the alignment fingers261A,263A of the anterior-posterior adjustment members261,263. In some embodiments, the medial-lateral alignment members260,262are attached to a C-shaped arm267for ease of handling, and to fix the distance between the members260,262. In some embodiments, the arm267has another shape, such as a straight bar. Fixation Procedure According to some embodiments, a method of positioning a foot includes assembling the foot plate assembly as shown inFIG.15. The patient's foot is placed onto the assembly200, with the heel directly over the heel support208. The heel brackets220are adjusted to enclose and support the heel. The forefoot brackets230are adjusted to secure the forefoot. The calcaneus is pinned with wires or pins242, such as 2.4 mm Steinmann Pin, and the wires or pins are cut. The members (e.g., struts300) are moved so that a wire or pin240(e.g., a 2.4 mm Bayonet tip pin) can be inserted through the eyelets309of the guides308of each strut300, and transversely across the midfoot bones. The compression knob310of the lateral strut300is advanced to move its abutting guide308to an inferior position (closer to plate202) relative to the guide308of the medial strut300. The wire or pin240is driven from a superior to inferior direction, through the eyelet309of medial strut300, the bones, and the eyelet309of the lateral strut300. The knobs306are then tightened to lock the struts300in position against the plate202. The wire or pin240is cut or bent. The compression knobs310are then tightened to compress the midfoot to the foot plate202. The configuration is now as shown inFIG.16. The screws210are retracted, the heel support208is removed, and the foot plate assembly200is attached to the ring164of the foot holder assembly100. The opening209of the foot plate202is placed around the ring164of the rotation base plate173. The screws210are advanced enough to retain the foot plate assembly200without locking the rotation angle of the assembly200. The rotational position of the foot plate assembly200can be moved to the angle for Mortise view. The configuration is now as shown inFIG.17. The tibia250is positioned in the support106of the joint space stabilizer assembly104, so the shaft of the tibia is parallel with the base102of the foot holder100. The tibia is rotated so the tibial tubercle is approximately perpendicular to the base plate102. The tibia is secured to the support104by inserting a wire or pin244(e.g., a 2.4 mm Bayonet tip pin) through the tibia and through openings107on medial and lateral sides of the support106, as shown inFIG.18. The wire or pin244can be bent to prevent it from backing out. Once the tibia250is secured, the joint space is set by using the knob112(to rotate the pinion114and position the rack116(FIG.1). This controls the tension of the ligaments and soft tissue of the ankle. Once the desired tension is achieved, the lock knob110can be used to fix the tension. The lock110is advanced to lock the position of the rack116. At this point, the position of the Achilles supports130can be adjusted and locked. Foot Alignment The Anterior-Posterior alignment members (e.g., rods)261,263are inserted through the socket168and opening or cutout169. In some embodiments, the members261,263are both attached to an arm265for ease of handling and to maintain proper spacing and orientation of each member, as shown inFIG.17. To obtain a better view of the ankle mortise, the patient's leg is internally rotated just enough so that the lateral malleolus (which is normally posterior to the medial malleolus), is on the same horizontal plane as the medial malleolus. Usually this involves approximately 10-20 degrees of internal rotation. In other words, when viewing the mortise view, the tibia and fibula are viewed without superimposition on each other. This mortise view represents a true anterior-posterior projection of the ankle mortise and also provides a good visualization of the talar dome. The apparatus described herein provides internal-external rotation while the foot is fixed by the footholder assembly100. Internal-External rotation is important in establishing the mortise-view for proper evaluation of the joint congruency and ligamentous balance, and for proper sizing of the prosthesis. Using the apparatus100described herein, the mortise view can be determined after the surgeon fixes the foot to the footholder assembly100. There is no need to unpin the foot prior to changing the rotation angle of the foot, or re-pin the foot after changing the angle. The foot can be placed in and pinned to the foot plate assembly200, and then footplate assembly200is attached to the footholder100. The mortise view can be established thereafter. The internal-external rotation allows surgeons greater degree of control and minimizes the chances of the foot orientation changing (which could occur when trying to pin the foot in the proper location if the angle of the foot plate could not rotate. Furthermore, in revision surgeries, establishing the mortise view is even more challenging than for a healthy ankle, since the boney anatomy is considerably damaged. The apparatus100described herein allows the surgeon to pin the foot in place on the footplate assembly200and consider several orientations, without re-pinning the foot every time the surgeon wants to change the internal-external rotation. The foot plate assembly200is rotated about the ring164, until a fluoroscopic anterior-posterior image of the ankle is as shown inFIG.19. The finger263A of member263is centered between the fingers261A of member261A, and is centered and aligned with the longitudinal axis of the tibia. The medial-lateral adjustment knob179(FIG.5) can be loosened, and the medial-lateral adjustment plate170can be moved to align the members161,163with the center of the talus. The U-bracket knobs147can be loosened, and the U-shaped bracket146can be rotated about an anterior-posterior axis until the anterior-posterior adjustment members261,263are parallel with the central axis of the tibia. If appropriate, translation (of the medial- lateral adjustment plate170) and rotation (of the U-shaped bracket146), and fluoroscopic verification can be repeated one or more times. When the correct position ofFIG.19is achieved, the U-bracket knobs147are tightened to fix the position. FIG.20shows an improper alignment for comparison. The finger263A of member263is not centered between the fingers261A of member261, and in this image, is hidden behind one of the fingers261A. The members261,253are not centered along the longitudinal axis of the tibia. With the anterior-posterior alignment completed, the medial-lateral alignment is checked. When viewed in a lateral fluoroscopic image, the medial-lateral adjustment members260,262should be aligned in the same manner as the anterior-posterior adjustment members261,263, as discussed above, with finger262A between fingers260A. The joint space between talus and tibia is also checked, and the Achilles support130can be adjusted for proper tibia position. The medial-lateral alignment is correct when a fluoroscopic medial-lateral image of the ankle shows the finger262A of member262is centered between the fingers260A of member260, and is centered and aligned with the longitudinal axis of the tibia. If the medial-lateral adjustment members260,262are not aligned with or parallel to the central axis of the tibia, the flexion knobs141(FIG.17) can be loosened, and the side plates152of the base plate assembly150are rotated about the medial-lateral axis143(FIG.3) until the medial-lateral adjustment members260,262are aligned with the central axis of the tibia. Then the flexion knobs141are tightened. In some embodiments, a lock is provided to prevent the flexion knobs141from loosening inadvertently once they are tightened. Upon returning to the anterior view, the anterior-posterior alignment is checked again, because it may have shifted during the medial lateral alignment. If appropriate, the anterior-posterior alignment is adjusted. The anterior-posterior alignment should be checked and/or adjusted last. A bushing (not shown) is inserted into the port172of the medial-lateral adjustment plate170. A cannula nut and collet (not shown) are inserted into the bushing. The bushing, cannula nut and collet are sized to receive a cannula280(FIG.21) and trocar (not shown). The trocar and cannula280are inserted through the soft tissue of the bottom of the foot, until the calcaneus is reached. The cannula nut is then used to lock the cannula280in place. The trocar is removed, and the drill bit282(FIG.21) is inserted. The drill bit282is used to drill the primary hole through the calcaneus and into the tibia. Joint Space Cuts FIG.22shows an exemplary embodiment of a resection guide cartridge holder402. Orthopedic revision joint procedures described herein provide the surgeon with a variety of implants in order to address the variations in the boney defect. The surgeon is provided a large selection of implants and an instrumented technique that allows surgeons to quickly template the boney defect. The resection guide cartridge holder402is an instrument that allows surgeons. to quickly connect various cut guides and sizing guides when templating the bone. An anterior fixture guide401(shown inFIG.26) is attached to the side plates152of the base plate assembly150. The anterior fixture guide401holds and positions the cartridge holder402ofFIG.22. The anterior fixture guide401permits the surgeon to adjust a position of the cartridge holder402in a superior-inferior direction relative to the talus272, while the cartridge holder402is attached to the foot holder100. The anterior fixture guide401can be the “INBONE®” Anterior Fixture Guide sold by Wright Medical Technology, Inc. of Memphis, Tenn. The Anterior Fixture Guide401has adjustments for moving the cartridge holder402in the superior/inferior direction, the medial/lateral direction, and/or the anterior/posterior direction, and rotate. For example, in some embodiments the anterior fixture guide401has an anterior/posterior adjustment knob405, a superior/inferior adjustment knob409, and a medial/lateral lock knob411. Once the position of the cartridge holder402is set, various sizing guides440and/or saw guides420can be reliably and repeatably positioned in the cartridge holder402. FIG.22is a front view of a cartridge holder402configured to be attached to an anterior fixture guide401(FIG.26) that mounts to the anterior side of the foot holder assembly100ofFIG.17. For example, in some embodiments, fasteners403attach the cartridge holder402to anterior fixture guide401. Anterior fixture guide401can be attached to the base102and provides a platform anterior to the base102and the calf of the patient, and superior to the surgical site. In some embodiments, the anterior fixture guide401can be positioned at a variety of locations along the superior-inferior direction. Referring again toFIG.22, the cartridge holder402has an opening406to receive either a saw guide (resection guide)420(FIG.23) or a sizing guide440(FIG.24). Once aligned and positioned, the cartridge holder402remains in place through both sizing and sawing, to accurately position the holes of the sizing guide440relative to the cuts made with the saw guide420(and vice-versa). Both the saw guide420and sizing guide440are sized and shaped to closely fit the opening406of the cartridge holder402. In some embodiments, multiple features ensure reproducible alignment between the cartridge holder402and the saw guide420or sizing guide440. For example, the opening406, saw guide420and sizing guide440are generally rectangular, and three sides of the saw guide420or sizing guide440abut corresponding sides of the opening406when the saw guide420or sizing guide440is in place. The cartridge holder402has a plurality of inwardly projecting tabs407positioned behind the rear surface of the saw guide420or sizing guide440. The tabs407abut the rear surface when the saw guide420or sizing guide440is properly located in the anterior-posterior direction. In some embodiments, the cartridge holder402has a dove-tail opening for receiving a corresponding dove-tail424on the saw guide420or sizing guide440. When saw guide420or sizing guide440is in place, a dove-tail joint is formed, resisting medial-lateral and superior-inferior motion. In some embodiments, the cartridge holder402has a pair of lock knobs408having locking tabs410. The saw guide420and sizing guide440have corresponding slots426on their side edges. When the knobs408are turned, the locking tabs410extend into the slots426to lock the saw guide420or sizing guide440and prevent any anterior-posterior motion. FIG.23is a front view of an embodiment of a saw guide420configured to be mounted in the cartridge holder402ofFIG.22. The saw guide420has a combination of a tibial slot428and a talar slot430. The surgeon selects an appropriately sized saw guide420that will not cut the fibula and preserves much of the medial malleolus. The surgeon performs the appropriate cuts, removes bone from the tibia and talus, and reams the primary hole in the tibia sufficiently to receive the stem701of the implant700(FIG.38). The saw guide420is removed from the cartridge holder402, and the sizing guide440is attached. FIG.24is a front view of a sizing guide440configured to be inserted in the cartridge holder402ofFIG.22. The sizing guide440ensures correct location of any pins or wires that are used during the ankle replacement surgery. FIG.25is an isometric view showing a saw guide mounted in the cartridge holder ofFIG.22.FIG.26is an anterior view of the assembly ofFIG.25mounted on the anterior fixture guide ofFIG.22. FIG.27is an isometric view showing the tibia250and talus272with the tibia trial502and the talar plate trial512therein. The trials502,512are used for proper sizing and to ensure that the bone surfaces have been cut properly with no bone fragments impeding proper positioning and seating of the tibial support and talar plate. FIG.28shows the tibia trial502with the poly insert trial503and the talar plate trial512with the talar dome trial514thereon. The trials allow verification of proper size and smooth range of motion. Once the surgeon is satisfied with the selection of trials, a pair of wires or pins520(e.g., 2.4 mm Steinmann pins) are inserted into the talus272through openings in the talar plate trial512, and the trials502,503,512,514are removed. Augment Reamer If the talus272has a pre-existing bone defect, such as a void272vFIG.29, a talar plate705(FIG.38) having an augment706can be used to fill the void272v. Some embodiments of this disclosure provide tooling for reaming the void272vto a predetermined size and shape to receive an augment of a predetermined size and shape. The surgeon utilizes an array of lolli-pop templates that define the shape and position of the talar defect. For example, in some embodiments, templates are provided in two different shapes, central and oblong, and two different depths, 6 mm and 10 mm. The surgeon templates the boney defect by referencing the augment sizer against the two angled pins520positioned at the neck of the talus272from the talar trial or talar sizer. Once the appropriate template is identified the surgeon will outline the defect based on the template. FIG.29shows a lolli-pop style augment sizer525used to determine the optimal augment size for filling a void in the talus272. In some embodiments, the augment sizer525has a neck521having a width that matches the distance between the pins520. In the exemplary embodiment ofFIG.29, the augment selection is made with reference to the pins520, and not necessarily with reference to the primary talar hole272h. In other embodiments (not shown), the augment sizer525has a pair of holes sized and positioned to receive the pins520. In other embodiments, once the augment reamer base600is slid onto the pins520, the arm604is adjusted till an axis of rotation of the reamer630is aligned with the previously drilled hole272hin the talus272. The surgeon tries a plurality of augment sizers525, and selects the one for which the least reshaping will be performed (thus preserving the maximum amount of bone). Once the augment size is determined, the void is reshaped, using the reamer base600and reamer630, as shown inFIGS.30-37. Additionally, the void can be reshaped using other operating room tools, such as, but not limited to, burrs, curettes, or the like. FIG.30is an isometric view of an augment reamer base600for positioning and aligning an augment reamer630for enlarging the void272vin the talus272to receive a predetermined augment706. The reamer base600is used after: cutting the talus272along a transverse plane to form a cut surface of the talus, wherein the talus has a void272vin the cut surface, the void having a size and a location; fitting a talar trial component512to the cut surface of the talus272; inserting a plurality of wires or pins520through the talar trial component520into the talus; and removing the talar trial component512. The reamer base600has an adjustably positionable arm604for positioning the reamer630. The arm has a circular opening606with a cutout608. The arm604is movable in the anterior-posterior direction. In some embodiments, the arm604is attached to a rail620, which is slidably mounted in a groove607in the reamer base body602. The rail620has a slot612, through which a locking screw622passes. When the locking screw622is tightened, a bearing surface (not shown) of locking screw622applies a force against the slide610, locking the position of the arm604. In some embodiments, each talar plate/augment configuration has a respective predetermined anterior-posterior position of the arm604with respect to the body602of the augment reamer base600. FIG.31shows a reamer630inserted into the opening606of the arm of the augment reamer base600. The reamer630has one or more blades632corresponding to the augment706that will be installed in the talus272. The reamer630has a means for limiting an advance of the reamer to a predetermined distance. In some embodiments, the means for limiting include an adjustable stop650. The reamer630has a feature (e.g., ridge)634for attaching a stop650(FIG.34). The reamer630also has a proximal end636configured for mounting in the chuck of a drill660(FIG.36). AlthoughFIG.31shows a D-shaped end636, a variety of shapes can be used to accommodate the chuck of the drill to be used. FIG.32shows the augment reamer base ofFIG.31with a collar640inserted in the circular opening606of the arm604. The collar640has a smooth circular inner diameter, configured to position and align the reamer630, while permitting the reamer to rotate freely. The collar640has an outer diameter642sized to fit within the circular opening606. A set of collars640can include respectively different inner diameters (for respectively different reamers630), but the same outer diameter642, sized to fit the opening606. The collar640has a locking member644sized to fit the cutout608of the circular opening606. FIG.33shows the augment reamer base ofFIG.32with the collar640rotated so the locking member644is in a locked position. This prevents the collar from being inadvertently removed from the arm604. FIG.34shows the augment reamer base ofFIG.33with a stop650positioned above the collar640. The stop650can have a variety of configurations. For example, in the example ofFIG.34, the stop650has a spring loaded member (not shown) which is biased to a locking position when no external force is applied to the release652. When the release652is pressed inwardly, the spring loaded member releases the ridge634, so the stop650can be removed. FIG.35shows the augment reamer base600ofFIG.34in position at the surgical site. The body602of the augment reamer base600has two diagonal holes configured to fit over the pins520, which were previously inserted at the conclusion of talar plate trialing. Sliding the holes in the body602of augment reamer base600over the pins520accurately locates the augment reamer base600relative to the location at which the talar plate705is to be attached. A supplementary threaded pin (not shown) can be placed at an oblique angle to provide greater stability to the instrument. FIG.36shows the augment reamer base600ofFIG.35with a drill660attached to the reamer630. The surgeon activates the drill660, and reams the talus until the stop650abuts the collar640. FIG.37shows the augment reamer base ofFIG.36after the reamer has advanced to a predetermined height, so the stop abuts the collar. The ridge634and stop650are configured to provide a predetermined distance between the bottom of the stop650and the bottom of the reshaped void272vwhen the stop650abuts the collar640. Because the ridge634locates the stop650at a predetermined distance from the bottom of the reamer blades632, proper functioning of the reamer630is not sensitive to the initial distance between the stop650and the collar640. Rather, a first distance from the bottom of the stop650to the bottom of the blades632corresponds to a second distance between the bottom of the talar plate705and bottom of the augment706. (The first distance and second distance can differ from each other by a constant, which depends on the height of the arm604above the cut surface of the talus272.). For example, the second distance between the bottom of the talar plate705and bottom of the augment706can be 6 mm or 10 mm in some embodiments. If the void272vis circular, and the augment706is circular, then a single reaming pass prepares the void for the augment. For oblong augments, the reamer630can be translated in the anterior-to posterior direction to achieve the proper boney preparation. To translate the reamer630, the knob622is loosened, the arm604is advanced or retracted, and the knob622is again tightened. The reaming and repositioning can be repeated one or more times to achieve the desired void configuration to receive the augment706. FIG.38shows the total ankle replacement700after insertion. The void272hhas been reshaped to accept the augment706of the talar plate705, with minimal void remaining between the augment706and bone. The talar dome704of the talar component is mounted on the talar plate705. The tibial component includes a stem701embedded in the tibia, with a tibia tray702attached thereto. The tibia tray702holds the polyethylene implant703. The total angle replacement700allows a wide range of articulating motion between the polyethylene implant703and the talar dome704. The ankle revision system ofFIG.38is exemplary, and is not limiting. The apparatus described herein can be used with other types of ankle revision systems, such as a pegged plate revision system, for example. Although the subject matter has been described in terms of exemplary embodiments, it is not limited thereto. Rather, the appended claims should be construed broadly, to include other variants and embodiments, which may be made by those skilled in the art.

11857208

DETAILED DESCRIPTION Disclosed is an aspiration device that can be used to aspirate an obstruction from a blood vessel. The disclosed aspiration device is configured to allow controlled one-handed aspiration yet maintain a syringe plunger “feel” of vacuum. The aspiration device also allows one-handed injection to empty the device when needed. Also disclosed are mechanisms that enable one-handed locking of a plunger position of the device to maintain vacuum when the user releases the device. Also disclosed are connectors that eliminate a flow restriction or step when a device is attached to a catheter. This permits an optimization of aspiration of a clot or occlusion from the catheter and all connections. Also disclosed are valve configurations that facilitate emptying the aspiration device in cases where the aspiration device is filled but further aspiration is desired. Embodiments that combine these features are also disclosed. Syringe-Type Aspiration Devices There exist current syringe-type devices that are configured to facilitate one-handed aspiration by a user squeezing portions of the device towards one another, rather than separating the syringe plunger and barrel as with a traditional syringe. However these types of devices lose aspiration force when the grip on the device is relaxed or released. Disclosed is a one-handed aspiration device having a latching feature, such as a latch, detent, or other locking mechanism, that enables locking the plunger in place, thus giving the user the ability to maintain vacuum force even when the user's grip is relaxed or released from the device, i.e. a vacuum lock. FIG.1shows an example of a syringe device100configured for one-handed aspiration. The syringe device100has a distal end110through which a fluid is injected or aspirated, and a proximal end115. The syringe100includes a main syringe barrel120that defines a chamber that can contain a fluid. A syringe plunger125is sized and shaped to slide within the barrel120so as to push fluid out of the barrel or pull fluid into the barrel in a well-known manner. An outer syringe barrel130is attached to the syringe plunger125such as via adhesive, snap fit, screws, etc. The syringe plunger125and outer syringe barrel130collectively form a body that is slideably coupled to the main syringe barrel120such that they can slide relative to the main syringe barrel120with a portion of the plunger125sliding through the chamber in a proximal or distal direction. FIG.2shows side and cross-sectional views of the syringe100. The syringe100includes a syringe plunger seal320attached to the end of the syringe plunger125to seal the fluid in the main barrel. The syringe100also includes one or more tabs305that are attached to a distal region of the outer syringe barrel130. One or more tabs310are attached to a proximal region of the main syringe barrel120at a location proximal of the tabs305. To aspirate fluid into the chamber, a user positions his or her fingers on a distal side of the tabs305such as with the index and middle fingers. The user also positions the thumb on a proximal side of the main syringe barrel tab310, as shown inFIG.3. The index/middle fingers and thumb are then squeezed together to move the tabs305and310toward one another, which causes the plunger125to move in a proximal direction relative to the inside of the main barrel chamber. That is, the movement of the outer syringe barrel305proximally will likewise move the syringe plunger125proximally (relative to the inside of the chamber) to create an aspiration force in the barrel chamber. In an embodiment, there is a vacuum lock consisting of a latching mechanism that can fix the outer syringe barrel130to the main syringe barrel120such that when the latch is actuated, aspiration force is maintained even if force on the finger tabs305and310are relaxed or released. A latching mechanism may comprise a feature on the outer syringe barrel that when toggled inward engages with a feature on the main syringe barrel to lock the two components together. To inject or expel fluid from the barrel chamber, the user places the index and middle fingers on a distal side of the main syringe barrel finger tabs310and the thumb on a proximal or proximal-most side the plunger125(or on a corresponding tab attached to the plunger125), as shown inFIG.4. The index/middle fingers and thumb are then squeezed together as described above. This causes the plunger125to move in a distal direction relative to the inside of the main barrel chamber and expel any fluid distally out of the chamber. One advantage of the above-described configuration over some other syringe handle configurations is that the sizes of the syringe100need not be much bigger than the size of a standard syringe of comparable volume. Another advantage of the syringe100is that the user's hand is set closer to or essentially over the body of the syringe, which allows good control/stabilization of the syringe as compared to some other aspiration devices. Another example of a one-handed manual aspiration device is a pistol grip style design; examples are disclosed in U.S. Pat. Nos. 4,594,073, 5,115,816, 5,469,860, and 5,830,152, all of which are incorporated herein by reference. In an embodiment, a pistol-grip style syringe aspiration device includes a latch mechanism to lock the plunger with respect to the main syringe barrel to create a vacuum lock.FIG.5shows embodiment of a syringe handle502in an assembled state andFIG.6shows the syringe handle502in an exploded state. The syringe handle502has a main handle body formed of a right main handle body505and a left main handle body510that collectively form a syringe barrel holder507that can receive a standard syringe705(as shown inFIG.7). A slide piece508is slideably coupled to the syringe barrel holder507when the right main handle body505and left main handle body510are joined together. With reference still toFIGS.5and6, a finger grip515is coupled to the slide piece508and a palm grip512is attached to the syringe barrel holder507. A finger toggle520is moveably attached to the syringe barrel holder507and configured to be moved upward or downward relative to a set of teeth or ratchets517on the slide piece508, such that the finger toggle520engages or disengages the teeth to lock the slide piece with respect to the syringe barrel holder507. With reference toFIG.7, a standard syringe705can be attached to the syringe handle502by pressing the syringe705into the barrel of the syringe handle502, with a flange810of the syringe705sliding into a slot of the main handle body510, and a proximal tab815of a plunger of the syringe705sliding into a proximal slot of the slide piece508. In this manner, the barrel of the syringe is fixed to the syringe barrel holder507and the syringe plunger is fixed to the slide piece508. In another embodiment, the syringe705may be integrated into the syringe handle502as a monolithic structure. To pull vacuum/aspirate fluid into the syringe705, the toggle520is set to the downward (disengaged) position, and the user holds the syringe handle502in a manner similar to a pistol with the index and middle fingers on the finger grip515and palm around the palm grip512. The user then squeezes the finger grip515towards the palm grip512to aspirate. The finger toggle520can be engaged with the ratchets517, by pushing the finger toggle520upward, at any time in order to maintain and lock vacuum on the syringe705by preventing motion of the syringe plunger with respect to the barrel. FIGS.8A and8Bshow the finger toggle520in two positions: an unlocked position (FIG.8A) where the finger toggle520does not engage the ratchets517, and a locked position (FIG.8B) where the finger toggle520engages the ratchets517(thereby limiting movement). The toggle may be configured with a snap feature such that the up and down positions are two stable positions of the toggle. For example, there may be a movable projection on one side and two detents on the other corresponding to the two positions. To inject fluid out of the syringe chamber, the user moves his or her hand to the main body handle, with the thumb placed on the back (proximal) side of the syringe plunger and pushes the thumb forward (distal) to move the plunger of the syringe in a distal direction through the chamber of the syringe. The vacuum lock concept may be applied to other aspiration syringe handle designs, for example those disclosed in U.S. Pat. Nos. 3,819,091, 4,711,250, and 4,850,979. An embodiment1005is shown inFIG.9.FIG.10shows the syringe handle1005in an exploded state. As best shown inFIG.10, the syringe handle1005is made up of at least four components (although the quantity of components may vary) including a main handle1010with a proximal palm grip1012, a left finger grip1020a, a right finger grip1020b, and a finger toggle1025. The components attach to one another to collectively form the assembled syringe handle1005. The left and right finger grips1020aand1020bare assembled to form the slideable finger grip1015. When assembled, the slideable finger grip1015captures the finger toggle1025and is slideably coupled to the main handle1010. When assembled, a standard syringe705can be attached to the syringe handle1005by pressing the barrel portion of the standard syringe into a distal seat1030of the main handle1010with a flange of the syringe body sliding into a slot1035of the main handle1010. The proximal tab of the standard syringe plunger slides into a slot1040of the finger grip1015.FIG.11shows the standard syringe705attached to the syringe handle1005. The finger toggle1025is configured to fix the position of the finger grip1015with respect to the main handle1010as shown inFIGS.12and13. In the on position shown inFIG.12, (which may be noted by a designation such as “0” on the finger grip), a set of internal teeth1305of the finger toggle are disengaged from corresponding teeth1310of the main body. The finger grip is thus free to move thereby allowing the user to retract (pull vacuum) and advance (inject) the plunger on the standard syringe by sliding the finger grip proximally or distally. In the off position shown inFIG.13(which may be noted by a designation such as “X” on the finger grip), the internal teeth1305of the finger toggle engage the teeth1310. This allows the user to lock the syringe plunger in place, as is necessary to maintain and lock the vacuum. To aspirate into the device1005or to create an aspiration force, the user places the index and middle fingers through the finger grip1015and secures the palm grip1012in his palm. The user then verifies that the finger toggle1025is in the on or “O” position. Using these two fingers, the user then pulls the finger grip towards the palm grip1012of the main handle1010. If desired, the user may then lock the syringe plunger in place (so as to maintain vacuum) by switching the finger toggle1025to the “X” position using a finger such as the forefinger. The opposite motion on the finger toggle1025using a finger such as the middle finger will disengage the lock. As above, the toggle may be configured to have two stable positions. To inject fluid from the device, the user then moves the index and middle fingers to the distal portion of the syringe main handle1010, with the thumb placed in the finger grip hole or on the back (proximal) side of the finger grip1015, and squeezes the finger grip1015and palm grip1012of the main handle1010together. In another embodiment of the syringe handle1005shown inFIG.14, the finger toggle1025is positioned outside of the finger grip1015. The finger toggle1025is positioned such that the actuation of the locking mechanism of the finger toggle1025can be ergonomically performed using the ring finger. The finger toggle1025is pulled back to disengage the teeth on the main handle (as shown inFIG.15A) and pushed forward to engage the teeth on the main handle lock the syringe plunger in place (as shown inFIG.15b). During use, it is often valuable for the user to note the level of vacuum in the aspiration device. For example, a loss of vacuum force indicates either that the blood vessel occlusion is being suctioned or has been suctioned into the catheter, or that the catheter tip has lost engagement with the occlusion. In addition, it may be important to know if the vacuum is too high. In some cases a vacuum that is too high may cause damage to the catheter and/or to the vessel wall, for example causing the catheter to collapse. In an embodiment of the aspiration device, the device includes an indicator127(FIG.1) which shows the level of vacuum in the main chamber of the aspiration device. This indicator may provide or otherwise indicate a pressure value, for example in mmHg. Alternately, the indicator may show or otherwise represent a pressure level and include markings to show when the level is above or below a target level. In this way, the user can visualize if the level of vacuum is being maintained or going down or is changing. In an embodiment, the vacuum indicator is a simple piston on a spring that is fluidly connected to the vacuum chamber, wherein the piston position varies depending on the amount of vacuum. Alternately, the vacuum indicator is a flexible bellow that has an inherent spring constant or which is connected to an external spring, and which shortens with increased level of vacuum. Markings on the housing may identify the length of the flexible bellows and relate this to the level of vacuum. In another embodiment, the aspiration device has a feature that maintains a constant level of vacuum. For example the piston generating the vacuum is coupled to a spring such that the pull-back force is constant. In a variation of this embodiment, the user can switch between manually controlling the vacuum force and switching to automated vacuum, for example with a switch that can engage or disengage the spring that generates the vacuum. This embodiment may also be used with or without the vacuum indicator described above. In this version, the pull back mechanism may be coupled to the vacuum indicator to allow for a constant vacuum. For example, the vacuum indicator is an electronic vacuum sensor, which imparts a signal to a solenoid actuated piston that generates the aspiration force. Connectors Connections to catheters have been standardized to a locking Luer taper design, with a male Luer taper connecting to a female Luer receptacle. The tapered connection provides a fluid-tight seal. Usually the male Luer connector has external threads and the female Luer connector has external features which can engage the threads when the connection is made, enabling the connection to be able to withstand pressure without the two sides of the connector coming apart. Typically catheter proximal hubs have a female Luer design. Syringes, stopcocks, Rotating Hemostasis Valves (RHVs), or other devices designed to connect to catheters have a male Luer design.FIG.16shows a cross-sectional view of a conventional male Luer connector on the distal tip of a syringe coupled to a female Luer connector on the proximal end of a catheter. When coupled, a distal end of the male Luer taper creates a ledge1705at the interface between the male and female connectors. During aspiration of clot through the catheter, the clot to may get caught or hung up on the ledge1705. The ledge1705also reduces the cross sectional area of the lumen for the clot to flow through. There is now described an unrestricted connector adaptor that replaces the male Luer which typically attaches to a female Luer connector on a catheter.FIG.17shows a cross sectioned perspective view of a connector adaptor1805on the distal tip of an aspiration device1822, coupled to a female Luer connector1810on the proximal end of a catheter1815. The adaptor1805provides a connection to the female Luer connector which eliminates the aforementioned ledge1705(FIG.16). The adaptor1805does not contain a taper that fits into the female connector1810, but instead seals the connection with a gasket1820on the top surface (i.e., proximal surface) of the female Luer connector1810. The adaptor1805can spin about a longitudinal axis of the catheter1815with respect to the main body of the aspiration device1822and contains internal threads1817. To attach the adaptor1805to the catheter, the two sides of the connection are pressed together and the connector1805is rotated to secure the internal threads to the external threads of the female Luer1810on the catheter such that the gasket1820is compressed to provide a fluid tight seal. FIG.18shows the system in cross-section, with a clearer view of the unrestricted interface between the female Luer hub of the catheter1815and the syringe1822with the adaptor1805providing a connection between the female Luer connector1810and the syringe1822. The adapter1805has a first, distal end1801with an opening that is configured to receive therein the female Luer connector1810. The gasket1820is positioned inside the opening such that the gasket1820abuts and seals against a proximal-most end of the female Luer connector1810when the female Luer connector1810is mounted inside the opening. The adapter has a proximal end1802with an opening that receives therein the distal most end of the syringe1822(or other device) through which fluid is aspirated into or injected out of the syringe. An internal contour or structure, such as a protrusion1807inside the adapter1805, links the opening that receives the syringe1822to the opening that receives the female Luer connector1810. The protrusion is sized and shaped to provide a smooth transition between the distal tip1809of the syringe1822and the proximal tip of the female Luer connector1810. The gasket1820also assists in providing the smooth transition. In this manner, the adapter1805provides an internal lumen connection between the syringe1822and the female Luer connector1810with the internal lumen connection providing a smooth transition that lacks any sudden steps or ledges. In this embodiment, the connector adaptor1805can rotate freely with respect to the aspiration device1822, such that the threads of the female Luer can be engaged without rotating the entire device. The gasket1820provides a fluid seal between the adaptor1805and the aspiration device1822such that there is no internal, stepped ledge in the lumen that connects the syringe1822to the catheter1815. FIG.19shows another embodiment of a connector adaptor2005. This adaptor2005includes a clasp structure2006that is configured to “snap” on to a portion, such as a flange2008, of the female connector2010. A leading edge of the flange2008and the clasp structure2006form bevels such that pushing the two components together allows the clasp features to automatically open and then snap over the flange2008. Squeezing on the back end of the clasp structure2006lift the front end of the clasp structure away from the flange2008and allows uncoupling of the connector. Valve In the situations where the clinician has filled the syringe to its maximum capacity, there is a need to expel the contents of the aspiration device, for example a syringe, in order to continue the aspiration thrombectomy. The clinician typically removes the syringe from the catheter in order to expel the contents of the syringe. This creates a loss of vacuum, as well as a risk of introducing air into the catheter as a result of the syringe being removed. If there was a strong vacuum force in the catheter due to clot being trapped in the tip of the catheter, for example, then there is a strong likelihood that removal of the syringe will draw air into the catheter. Alternatively, the clinician may attach a three-way stopcock between the catheter and the syringe or aspiration device, wherein a third port of the stopcock leads to a receptacle to store the aspirant. However, standard three-way stopcocks can at times be confusing as to which ports are open and which port is closed. In addition, standard stopcocks require two hands to open, and two hands to close. Further, the connections to standard stopcocks are Luer connections with their associated restriction and ledge, creating a potential for thrombus or other emboli to be trapped in the valve. There is now disclosed a spring-loaded, push button stopcock2205as shown inFIG.20. The stopcock2205requires only one hand to open. A user can simply release the stopcock2205to close it. The stopcock2205includes three ports2210,2215, and2220and an actuator such as a spring-loaded button2225. In a default state wherein the button2225is not compressed, there is a direct flow between an attached catheter and a syringe to allow for aspiration, as shown inFIG.21. When the button2225is actuated (such as by being compressed), the fluid path changes to allow expulsion from the syringe to an attached receptacle, as shown inFIG.22. As shown in the embodiment inFIGS.21and22, the valve connections may be configured to be unrestricted. All the aforementioned valve designs may incorporate the adaptor as described above to minimize the possibility of clot being trapped in the valve during aspiration or emptying of the aspiration device. Alternately, the catheter proximal hub may be configured with a shut off valve such that when the aspiration device is removed, the hub automatically closes so that there is no loss of vacuum or possible introduction of air.FIGS.23and24show one embodiment (in side and side cross-sectional views) of such a valve built into a catheter proximal hub2405.FIG.23shows the hub2405with a valve in a closed state andFIG.24shows it in an open state. The catheter proximal hub2405includes a valve seat2410, a valve cap2420and a valve seal2430which is normally closed. The valve seal2430may be, for example an elastomeric and/or resilient seal with an inner lumen such as a short length of tube. The valve cap2420contains an inner tubular structure2422and a proximal female Luer connector2425. The valve seat2410contains external threads and the valve cap contain internal threads such that when the cap is turned, the internal tube is pushed forward to compress the seal2430such the inner lumen of the seal is occluded, as inFIG.23. When the cap is turned in an unscrewing direction, the tube moves back, decompressing the seal2430thereby allowing the inner lumen to open, as inFIG.24. The proximal female Luer connector allows the catheter to be prepped with a standard syringe when the valve is in the open state. In another embodiment, as shown inFIGS.25and26, the valve seat2610and valve cap2620are slideably connected to one another.FIG.25shows the device with a valve in a closed state andFIG.26shows it in an open state. The valve seal2630may be, for example, a septum valve with a slit or slits. The valve cap2620contains an inner tubular structure2622and a proximal female Luer connector2625. An internal compression spring2615biases the valve seat and valve cap to keeps the two components normally apart, as shown inFIG.25. When the cap is pushed forward, the internal tube2622is pushed forward through the valve seal2630to open the valve, as shown inFIG.26. A latch between the valve seat and the valve cap may keep the valve in the opened configuration. However, before the user disconnects the syringe or other aspiration device, the user releases the latch and the compression spring2615pulls the internal tube2622away from the valve2630and allows the valve to close, as inFIG.25. There may be embodiments of aspiration devices and catheters connections that combine several of the features disclosed herein. For example, inFIGS.27A,27B, and27C, a catheter hub2805includes a shut-off valve2815configured to be connected to an aspiration device2810via an unrestricted connector. The connector may contain a latch structure2820that locks the aspiration device2810to a flange structure2825of the hub2805. When the aspiration device2810is pushed forward onto the catheter hub2805, an unrestricted connection is formed between the aspiration device2810and the catheter hub2805and simultaneously the valve2815is opened to create a smooth and unrestricted lumen from the body of the catheter into the aspiration device. When the aspiration device2810is removed, a spring in the shut off valve2815prevents loss of vacuum in the catheter. In another embodiment, as shown inFIG.28, the aspiration device2900is connected using an unrestricted connector design via a push button valve2905to the catheter2915. This allows unrestricted aspiration through the catheter when the valve is in the aspiration state, as inFIG.29A, and allows unrestricted purging of the aspiration device2900when the valve2905is in a purge configuration, as inFIG.29B. The valve2905may be monolithic with the aspiration device such that the components and connections are minimized. As shown, the aspiration device is configured to be optimized for one-handed aspiration. As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope of the subject matter described herein. Any recited method can be carried out in the order of events recited or in any other order which is logically possible. Although embodiments of various methods and devices are described herein in detail with reference to certain versions, it should be appreciated that other versions, embodiments, methods of use, and combinations thereof are also possible. Therefore the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.

11857209

DETAILED DESCRIPTION In one aspect, the present teachings are described more fully hereinafter with reference to the accompanying drawings, which show certain embodiments of the present teachings. The present teachings may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to illustrate various aspects of the present teachings. Like numbers refer to like elements throughout. In one aspect, the present teachings provide catheter-based emboli removal systems. In some embodiments, a system of the present teachings is used to remove blood clots from vessels in the body. In some embodiments, the vessels are veins and/or artery. In some embodiments, the system is used to treat, in veins, deep vein thrombosis (DVT), and in arteries, pulmonary embolism (PE), ST-elevated myocardial infarction (STEMI) and ischemic stroke. In some embodiments, the systems can also quickly clear dialysis arteriovenous grafts, which are prone to thrombus formation. According to some embodiments, when the catheter-based emboli removal system of the present teachings is deployed into a blood vessel, the emboli removal device is expanded and moved proximally along the vessel so that the embolus is substantially contained with a mesh basket of the emboli removal device. Specifically, the present teachings provide a device/system and methods of removing neurocranial emboli without causing any distal complication arising from the dislodgement of larger pieces of a recovered embolus distal to the location of the original embolus. As used herein, the terms “radially outward” and “radially away” means any direction which is not parallel with the central axis. For example, considering a cylinder, a radial outward member could be a piece of wire or a loop of wire that is attached or otherwise operatively coupled to the cylinder that is oriented at an angle greater than 0° relative to the central longitudinal axis of the cylinder. As used herein, the term “lumen” means a canal, duct, generally tubular space or cavity in the body of a subject, including veins, arteries, blood vessels, capillaries, intestines, and the like. The term “lumen” can also refer to a tubular space in a catheter, a microcatheter, or the like in a device. As used herein the term “proximal” shall mean closest to the operator (less into the body) and “distal” shall mean furthest from the operator (further into the body). In positioning the medical device from a downstream access point, distal is more upstream and proximal is more downstream. As used herein the term “emboli” used herein can be clot, thrombus or the like, and these terms may be used interchangeably. As explained in further detail below, various embodiments of the present teachings provide medical devices/system for removing blood clots from a vessel in the body. In some embodiments, the medical devices/system according to the present teachings may include an embolic capture device or means configured to capture the clot. In some embodiments, a pusher shaft joins the embolic capture device. In some embodiments, the pusher shaft pushes and/or pulls, the embolic capture device. In some embodiments, the embolic capture device according to the present teachings may be extended into an elongated profile for percutaneous delivery, and resume to a radially expanded deployment profile for capturing the clot, and be extended into a second elongated profile to retrieve the clot. As used in this application, unless otherwise indicated, the term “vessel” refers to a blood vessel, including an artery, an arteriole, a capillary, a venule, a vein or a network of any of the combinations of the foregoing. In another aspect, the present teachings disclose an embolic capture device for intracranial use. According to some embodiments, the embolic capture device has a general profile of a stent that is flexible and atraumatic, and is available in various lengths and diameters, thin-walled, and/or radiopaque. In some embodiments, the stent is configured to be precisely delivered, retrieved, and repositioned. In some embodiments, the stent is flexible enough to be delivered via a microcatheter and to be placed in a small vessel but has sufficient radial forces to conform to the vessel wall geometry when deployed. In another aspect, the present teachings disclose an embolic capture device with an elongated delivery profile. In some embodiments, the embolic capture device has an expanded deployed profile. As described in detail below, in some embodiments, the embolic capture device could have a straightened, elongated, low-profile delivery configuration suitable for delivery via a delivery system. In some embodiments, the deployed configuration of the embolic capture device substantially engages the blood vessel within which it is deployed. When an embolic capture of the present teachings is used to retrieve an emboli, a positioning guide wire is first threaded through the blood vessel across a blood clot. A microcatheter then threads over the positioning guide wire and having its distal end positioned distal to the clot. The positioning guide wire is then removed, followed by a pusher shaft joining to a proximal end of an elongated embolic capture device extending through the lumen of microcatheter. While holding elongated embolic capture device steady, a clinician withdraws the microcatheter proximally to uncover the device. Once outside of the microcatheter, the embolic capture device expands to engage the clot. In one embodiment, the device is deployed distal to the clot. In another embodiment, the device is deployed across the clot. In some embodiments, to retrieve the clot, the clinician pulls the pusher shaft proximally, the embolic capture device is pulled proximally back, carrying the blood clot back into a larger catheter, guide catheter, or distal access catheter (DAC). The techniques disclosed for delivering and deploying the embodiments described herein are only examples. It should be understood that other techniques can be used instead of, or in combination with, these teachings. For example, the techniques used to deploy an embodiment of the devices described herein depend on the particular features of the device, the delivery system, and the anatomy in which the device is being deployed. FIG.1shows an exemplary embolic capture device (10) for insertion into a human vasculature according to the present teachings. The device (10) can be used, for example, to remove blood clots. This present teachings can also be applied to other medical devices, for example, stents, flow dividers, filters, and the like. The device is particularly suitable in stent-like systems that are used to influence flow. This present teachings can be generally applied to implants or other medical devices that can be released temporarily in the body and be retractable into the corresponding delivery system. The retractability can play a role in repositioning a device, such as stents, or generally in the recovery of a temporarily released medical device. FIG.1shows an embodiment of the embolic capture device (10) of the present teachings in its pre-set deployed configuration. The embolic capture device (10) comprises a hollow stent body (12) with a generally cylindrical shape, a proximal end (14) and a distal end (16). The stent body (12) of the embolic capture device (10) also has a longitudinal axis “L”. The proximal end (14) of the stent body (12) joins to a distal end of the pusher shaft (not shown) of a delivery system (not shown) by a plurality of struts (18a,18b). For example, two connecting struts (18a,18b) at the proximal end of the stent body (12) are joined together with a distal end of the pusher shaft (8) by a marker band forming an off centered attachment between the proximal end (14) of the device (10) and the distal end (16) of the pusher shaft (8), for example, such as one shown inFIG.2A. In another embodiment, four connecting struts (19a,19b,19c,19d) at the proximal end of the stent body (12) are attached together with a distal end of the pusher shaft (8) forming a balanced, more symmetrical attachment between the proximal end (14) of the embolic capture device (10) and the pusher shaft (8), for example, such as shown inFIG.2B. In one embodiment, the pusher shaft (8) is fixedly attached to the device (10). In an alternative embodiment, attachment between the pusher shaft (8) and the device (10) is detachable. FIG.2Cillustrates a detailed view of the connection between the stent body (12) and pusher shaft (8). As shown in the figure, a marker band (17) in a shape of a tube is attached over the proximal ends of two connecting struts (18a,18b) and the distal end of the pusher shaft (8). According to one embodiment, the proximal ends (15a,15b) of the connecting struts (18a,18b) are formed into a flat disk shape, the distal end (9) of the pusher shaft (8) is formed into an enlarged profile that is greater than the inner diameter of the marker band (17). As seen in the figure, the proximal disc ends (15a,15b) connecting struts (18a,18b) extends beyond the proximal end of the marker band tube (17), the distal ball end (9) of the pusher shaft (8) extends beyond the distal end of the marker band tube (17), and as marker band (17) fixed over the connecting struts (18a,18b) and the distal end (9) of the pusher shaft (8), a mechanical lock is formed between the pusher shaft (8) and the stent body (12). According to one embodiment, such mechanical lock is configured to create a tensile force between the pusher shaft and the embolic capture device of 5N to 15 N. Additionally, in some embodiments, the mechanical lock between marker band and the pusher shaft as well as the pusher shaft could be formed by crimping, adhesive, or both. For example, epoxy or solder could be added to both ends of a crimp lock between the connecting struts and the distal end of the pusher shaft. According to some embodiments, the marker band (1) could be made of material such as platinum tungsten alloy, platinum iridium alloy, or platinum. The marker band (17) could have an overall inner diameter of 0.005″ to 0.015″, a wall thickness of 0.001″ to 0.0025″, and a general length between 0.010″ to 0.040″. Referring back toFIG.1, the embolic capture device (10) has a wall in the form of an array of openings, or cells. Each of such cells (20) is configured to expand and collapse laterally. According to one embodiment of the present teachings, the embolic capture device (10) expands upon deployment in vivo. In one embodiment of the present teachings, upon deployment, the embolic capture device (10) expands radially due to the elastic nature of the material. In another embodiment, such radial expansion is achieved by the pre-set thermal shape memory of the device material. In yet another embodiment, such radial expansion is achieved manually via an inflating balloon. In some embodiments, the embolic capture device is made of stainless steel, nitinol, Titanium, Elgiloy, Vitalium, Mobilium, Ticonium, Platinore, Stellite, Tantalum, Platium, Hastelloy, CoCrNi alloys (e.g., trade name Phynox), MP35N, or CoCrMo alloys, any other metallic alloys, or a mixture thereof. According to some embodiments of the present teachings, the embolic capture device (10) has an array of closed cell structure which allows the device (10) to collapse during the delivery and expands upon the deployment.FIG.3illustrates one embodiment of the cell (20) structure design. As illustrated, each cell (20) comprises two continuous struts (26,28) connected at two spots forming a distal end (24) and a proximal end (22) of the cell (20). As shown, both the struts (26,28) are pre-formed into an arc with a desired curvature. When the cell (20) is at a relaxed state, two struts (26,28) arc away from each other as shown inFIG.3. When the cell (20) collapses, the distal and proximal ends (22) of each cell (20) move away from each other leading to both struts (26,28) being straighten and moving closer to each other. In one embodiment, the cell (2) has two identical upper and lower ac length and curvature, and a horizontal cell axis. Now referring toFIG.4A, an embodiment of the embolic capture device (10) is illustrated in an unwrapped configuration. As shown inFIG.4A, a number of cells (20a,20b,20c,20d) connect to each other in a longitudinally direction forming a row of cells (30b). In one embodiment, five rows (30a,30b,30c,30d, &30e) of cells with the same cell number are arranged next to each other in an offset radial fashion. That is the most proximal cell (20a) in a row (30b) is arranged proximal to the most proximal cell (21a) of at least one of its adjacent rows (30a), and in turn, the most distal cell (20e) in this row (30b) is also arranged proximal to the most distal cell (21e) of at least one of its adjacent rows (30a) as shown inFIG.4A. The offset distance as shown inFIG.4Ais half of the expanded cell length. That is the proximal end of the cell (21a) in row (30a) starts at the peak curvature of cell (20a) in row (30b), and the distal end of the cell (20e) in row (30b) ends at the peak curvature of cell (21e) in row (30a). Thus, each cell shares some portions of the struts with adjacent cells. For example, as shown inFIG.4A, cell (20a) share half of the strut with the cell (21a), and half of the other strut with cell (23a). One skilled in the art should understand thatFIG.4Aillustrates an unwrapped version of the stent body. Once forming in a tubular configuration, a 6throw of cell would be formed when joining the peak curvature of cells in row30awith the peak curvature of cells in row30e. This 6throw of cell would have one less cell number comparing to the adjacent rows (30a,30e) of cells. In another embodiment, two struts forming each cells have identical length and symmetrical profile across the horizontal cell axis of each cell, for example as shown inFIG.4A. In one embodiment, all cells in an embolic capture device have the same shape, size and configuration. In another embodiment, cells in an embolic capture device have various shape, size and configuration. FIG.4Afurther shows that two connecting struts (18a,18b), with each of their distal end connecting to the proximal end of one most proximal cells (20a,25a), and their proximal ends joining together and attaching to a distal end of the pusher shaft (not shown). According to one embodiment of the present teaching, where rows of the cells making up one device such as the one shown inFIG.1. According to one embodiment of the present teaching, the device has a longitudinal axis “L” that is parallel to the horizontal cell axis of each row of cells. As shown inFIG.1, in such exemplary embodiment, the device (10) has a longitudinal lumen with all cell expanded to their pre-set configuration. The closed cell structure forms a complete cylindrical surface along middle and distal portions of the device (10) as shown inFIG.1. The proximal portion of the device (10) has a partial cylindrical surface formed by rows (30b) and (30d) of the cells according to one embodiment of the present teaching. FIG.4Billustrates another embodiment of present teaching, where the device (40) having four struts (19a,19b,19c,19d) connecting to its proximal end in an unwrapped configuration. In this embodiment, the device (40) is made of eight rows of cells arranged in the similar fashion as described above with reference toFIG.4A. The unwrapped configuration as shown here illustrates 7 rows of cell, one skilled in the art should understand that once forming in a tubular configuration, a 8throw of cell would be formed when joining the peak curvature of cells in row42awith the peak curvature of cells in row42g. Unlike exemplary embodiment shown inFIG.4A, each adjacent rows of cell has different numbers of cells. For example, as shown inFIG.4B, row42bhas 5 cells, and its adjacent rows42aand42c, each has 6 cells. The very proximal cell on row42bstarts distal to the very proximal cell on row42aand row42cby a half of the cell strut length. That is, the proximal end of the cell (41b) in row (42b) starts at the peak curvature of cell (41a) in row (42a) and at the peak curvature of cell (41c) in row (42c). Since row42bonly has 5 cells, the distal end of the cell (43b) in row (42b) ends at the peak curvature of cell (43a) in row (42a), and at the peak curvature of cell (43c) in row (42c). In another embodiment, two struts forming each cells have identical length and symmetrical curvature across the horizontal cell axis of each cell, for example as shown inFIG.4A. In one embodiment, all cells forming an embolic capture device have the same shape, size and configuration. In another embodiment, cells in an embolic capture device have various shape, size and configuration. FIG.4Bfurther shows that four struts (19a,19b,19c,19d), with each of their distal end connecting to the proximal end of the most proximal cells (41a,41c,41e,41g), and their proximal ends joining together and attaching to a distal end of the pusher shaft (not shown). According to one embodiment of the present teaching, the device has a longitudinal axis “L” that is parallel to the horizontal cell axis of each row of cells. As shown inFIG.1, in such exemplary embodiment, the device (40) has a longitudinal lumen with all cell expanded to their pre-set configuration. The closed cell structure forms a complete cylindrical surface along its proximal, middle and distal portions of the device (40). According to some embodiments, device with four connecting struts at its proximal end general has even number of rows of cells. And device with two connecting struts are its proximal end could have either even or odd number of rows of cells. In another embodiment, for ease the describing various embodiment, illustration are general referring to device with four connecting struts. One skilled in the art should understand that two connecting struts could be incorporated instead of four. In addition, although a certain number of rows and a certain number of cells in one row are illustrated in the exemplary embodiment for the purpose of describing, one skilled in the art should understand, the number of rows, and the number of cells in one row could increase or decrease in order to achieve the treatment purpose. Continue referring back toFIG.3, an imaginary line connecting the distal end and the proximal end of each cell forms a cell axis (32). The cell also defines a height and a width as shown in theFIG.3. The cell length is the linear distance between the distal and proximal ends (22,24) of the cell (20) in a direction parallel to the longitudinal axis “L”. The cell height is the linear distance between the peaks of the cell/cell struts in a direction perpendicular to the longitudinal axis “L”. In one embodiment, such as shown inFIG.3, both struts (26,28) have the same length and symmetrical arcs across the cell axis (32). In one embodiment, the cell axis (32) is parallel to the longitudinal axis “L” of the device (10) as shown inFIG.4A. With such configuration, when the device (10) is released from the delivery sheath, the struts (26,28) forming each cell resume their arc profiles, with their distal and proximal ends (22,24) moving away from each other, and two struts (26,28) arc away from each other leading to an expansion of the cell (20) until it reaches its designed height and length. Since the cell axis (32) is parallel to the longitudinal axis “L” of the device (10), and struts forming each cell has the identical length and symmetrical curvature across the cell axis, each cell will expand in a direction perpendicular to the longitudinal axis “L”. Thus the device (10) would expand evenly in a radial direction, perpendicular to and radially outward from the longitudinal axis “L” of the device, with no axial rotation around the longitudinal axis. FIG.5Aillustrates another exemplary cell (50) design. In this example, both the struts (52,54) forming the cell still have the same length. The curvature on each struts (52,54) are no longer symmetrical across the cell axis. Specifically, the curvature of each struts (52,54) are rotational symmetrical to each other across the center of the cell (50). Unlike what is shown inFIG.3, the cell axis (55) angles from the longitudinal axis “L” of the device by “θ”, as shown inFIG.5A. With this configuration, when the device is released from the delivery sheath, the distal and proximal ends (56,58) of the cell (50) move radially away from each other, and the struts (52,54) forming each cell (50) resume their arc profiles and also arch away from each other leading to an expansion of the cell (50) until it reaches the designed length and height. Since the cell axis (55) angles from the longitudinal axis “L”, the direction of both struts (52,54) expands is no longer perpendicular to the longitudinal axis “L” of the device (50). Thus, instead of expanding in a perpendicular direction to longitudinal axis “L”, one strut (52) of the cell expands in an angle “θ1” to longitudinal axis “L”, the other strut (54) of the cell expands in an angle “θ2” to longitudinal axis “L”. With all the cells forming the circumference of the device (60) lumen expand in the above described direction around the longitudinal axis “L”, the device would rotate around the axis “L” as it expands. FIG.5Aillustrates the exemplary cell design, where, comparing to the proximal end (56) of the cell (50a), the distal end (58) of said cell (50a) is clock-wise rotating around the longitudinal axis “L” of the stent body to a degree. In another word, the cell axis, a straight line connecting the proximal end and distal end (56,58) of the same cell (50a) is no longer parallel to the longitudinal axis “L” of the stent body. Thus, during deployment, as the two struts (52,54) forming the cell (50a) arch away from each other, said cell (50a) would expand and rotate in a clockwise fashion. Additionally,FIG.5Billustrates another exemplary cell design, where, comparing to the proximal end of the cell (50b), the distal end of said cell (50b) is counter clock-wise rotating around the longitudinal axis “L” of the stent body to a degree. In another word, the cell axis, a straight line connecting the proximal end and distal end of the same cell (50b) is no longer parallel to the longitudinal axis “L” of the stent body. Thus, during deployment, as the two struts forming the cell (50b) arch away from each other, said cell (50b) would expand and rotate in a counter clockwise fashion. According to some embodiments of the present teachings, when the cell height and cell length of each cell are the same so that the angle between the cell axis and the longitudinal axis “L” is about 45°. According to some embodiments of the present teachings, the height and length of each cell are different, such as shown inFIG.5A. One skilled in the art should understand that the configuration of both cell height and cell length of each cell would result various expansion motion of that cell. In another word, varying cell height and cell length ration could result in different the degree of cell rotation during deployment, and/or the speed of cell rotation during deployment. And a combination of the motion of all cells made up a stent body would in turn affect the overall deployment movement of the stent body. For example, with a greater cell height to cell length ration, said cell would rotates more during expansion. And thus a stent body with cells that having a greater cell height to cell length ratio would rotate more radially during deployment than a stent body with cells that having a less cell height to cell length ratio. In another example, as the cell height to cell length ratio increases, that is as the angle between the cell axis and the longitudinal axis “L” of the device increases, the speed of the axial rotation also increases at a given stent body length. According to some embodiments of the present teaching, the stent body would be made of cells of same size throughout. In another embodiment, the stent body would be made of cells of various size. In yet another example, a stent body formed with relatively small cells will increase the stiffness and torque strength of the stent body during its axial rotation. According to some embodiments of the present teachings, the curvature on both struts (26,28) are symmetrical across the cell axis (32) as shown inFIG.3. According to some embodiments of the present teachings, the curvature on one or both the struts could by off-centered, such as shown inFIG.7. According to another embodiments, the curvature on both struts forming the same cell are not symmetrical across the cell axis, but are rotational symmetrical across the center of the cell axis, such as shown inFIGS.5A-5B &7. FIG.6illustrates an exemplary embodiment of the stent body where an array of identical cells forms a device (60). As shown in this figure, all cells have identical shape, size and orientation, i.e. all cells have the same cell heights, same cell lengths, and same angle between cell axis and the longitudinal axis “L” of the stent body. As a result, upon a deployment, the device will expand radially while rotate at a steady speed. One skilled in the art should understand that with a combination of different cell configuration, the stent body could be programmed to have different deployment motion. For example a portion of the stent body could have a clockwise rotation motion, while another portion of the stent body could have a counter clock wise rotation motion. In another example, a portion of the stent body could have accelerated or decelerated rotation speed then the rest portion of the stent body. In yet another example, a portion of the stent body could have a greater rotation range/degree than the rest portion of the stent body. According to some embodiment, the struts forming the cell could have simple curvature as shown inFIGS.3,5&7. In another embodiment, the struts (86,88) forming the cell (80) could have a wavy profile, as shown inFIG.8. Such wavy profile could ensure the stent body to be flexible when deployed at treatment location, and not kink (or collapse) while going through an acute angle, such as tortuous neurovascular paths. As mentioned above, the struts forming the same cell does not have curvature symmetrical across the cell axis. Instead the strut curvature are rotational symmetrical across the center of the cell axis. In addition to a cell's geometrical construct, the physical character of the struts forming each cell could also affect the performance of the stent body. Specifically, the size of struts forming each cell could directly affect the torque of torsion during cell deployment. According to some embodiments of the present teachings, the size of the struts, i.e. the thickness and the width, forming the same cell could various from cell to cell. As the size of the struts increase, i.e. the width and/or the thickness of the struts increases, the cross section of the struts increases, the torque strength of the device also increases during said cell's deployment rotation. One skilled in the art should understand that a greater rotation torque could lead to a better engagement with blood clot. Now referring back toFIG.1, an array of identical cells forms the device (10). Since all the cells have their cell axis parallel to the longitudinal axis “L” of the stent body, upon a deployment, the entire portion of the stent body will expand radially as it exists the microcatheter without any radial twisting. Now referring back toFIG.6, an array of identical cells forms a device (60). All cells have their cell axis forming a same angle against the longitudinal axis “L” of the stent body, upon a deployment, the stent body will expand radially while rotate radially around the longitudinal axis “L” of the stent body at a steady speed. According to some embodiments of the present teachings, the stent body could have all cells with the same configurations, such as shape, size, orientation, as well as the size of the struts, such as exemplary embodiment shown inFIGS.4A,4B, and6. In another embodiment, the stent body could have some cells with various configuration from section to section. For example, as shown inFIG.9, the first distal circumferential row (91a) of cells have a first cell axis forming a first angle (α1) with the longitudinal axis “L” of the stent body, while the second circumferential row of cells (91b) proximal to the first row (91a) have a second cell axis forming a second angle (α2) with the longitudinal axis “L” of the stent body. With this configuration, as the device (90) expands, it will rotate to a first direction at a first speed as the first row of cells (91a) expand, followed by a change of direction, rotate to a second direction at a second speed as the second row (91b) of cells expand. In another embodiment, the stent body could have cells with different size and shape throughout out its entire length. For example, as shown inFIG.10, the first distal circumferential row (101a) of cells have a first cell size and their cell axis are parallel to the longitudinal axis “L” of the stent body; the second circumferential row (101b) of cells proximal to the first row (101a) have a second cell size and angled cell axis to the longitudinal axis “L” of the stent body, several circumferential rows of cells proximal to the second circumferential row (101b) have a third cell size and a different angled cell axis to the longitudinal axis “L” of the stent body. Then followed by circumferential row of cells with reversed orientation and etc. With this configuration, as the device (100) expands, part of the stent body will expand without radial twisting, portions of the stent body will rotate initially with a first speed and torque strength toward a first direction as the second row (101b) of cells expand, followed by a change of axial rotation speed, torque strength as the rest circumferential rows of the cells expand. Thus, according to some embodiments, the device deployment motion could be programed by changing in one or more of those above-mentioned design criteria, specifically, cell size, cell height to cell length ratio, the angle between cell axis to the longitudinal axis “L” of the device, cell strut size, cell strut curvature, and the number of cell in each circumference row and longitudinal row. According to some embodiments, a combinations of the angles between the cell axis and longitudinal axis “L” of the overall stent body, the height to length ratio of each cell, the cross section of struts forming each cell, the size of the cell, and the curvature profile of the cell struts can all be engineered in order to program the deployment movement of the device. Thus, one skilled in the art should understand that the combinations of different factors of the cell and/or device design, could result various programmed deployment motion of the embolic capture device, such as clock wise rotation, counter-clockwise rotation, zig zag movement, accelerating motion along the length of the device and/or decelerating motion along the length of the device. Thus the present invention could be used to pre-program a stent body allowing its deployment motion to be customized according to the treatment location, the size of the blood clot to be captured, the patient anatomy, as well as the physician's preference and etc. Thus, the exemplary embodiment as shown in the figures, and description herein, should not be viewed as limiting to the scope of the present teaching. According to some embodiments of the present teaching, the cell of the device could have a width of 1-10 mm, and a height of 1-5 mm. Each cell could be made of struts having 0.001-0.010″ width and thickness. A device could have 2-10 row of cells, with 4-20 number of cells in each row. Upon deployment, the device could have 2 mm-8 mm in diameter, and 15 mm-60 mm in length. In yet another embodiment, the expansion ratio in diameter is 2-30. The angle between the cell axis and the longitudinal axis “L” of the device could ranges from 15-75 in either direction. The device could be designed to rotate in a continuous left-hand motion, a continuous counter clock wise motion, or a twisting motion such as a clock wise motion followed by a counter clock wise motion then followed by another clock wise motion and etc. While most existing solutions in the market rely on the radial expansion of the device across the blood clot for capturing the clot, the torsion and torque provided in the present teaching creates a new force and motion that adds on to radial expansion of the device. As a result, the device not only engages the blood clot axially, but also engages the clot radially. This allows the device actively and securely engaging and retrieving the blood clot. Now referring toFIGS.11-13, an embolic capture device (110) has multiple layers of stent body.FIG.11Aillustrates multi-layer embolic capture device (110) in its deployed configuration with its proximal end joining a pusher shaft (8).FIG.11Billustrates a detailed view of the connection between the embolic capture device (110) and pusher shaft (8) connection.FIG.12Aillustrates a hypothetical unwrapped view of the inner stent body (120) with its cell configuration.FIG.12Billustrates an expanded profile of the inner stent body (120) alone.FIG.13Aillustrates a hypothetical unwrapped view of the outer stent body (130) with its cell configuration.FIG.13Billustrates an expanded profile of the outer stent body (130) alone. Now referring toFIG.11B, similar to what has been described with reference toFIG.2C, a marker band (127) in a shape of a tube is fixed over the proximal ends of connecting struts on the inner stent body (120) and the distal end of the pusher shaft (8). As seen in the figure, the proximal disc ends connecting struts extends beyond the proximal end of the marker band tube (127), the distal ball end of the pusher shaft (8) extends beyond the distal end of the marker band tube (127), and as marker band (127) fixed over the connecting struts of the inner stent body (120) and the pusher shaft, (8) a mechanical lock is formed between the pusher shaft (8) and the inner stent body (120). Continue referring toFIG.11B, the proximal connecting struts on the outer stent body (130) is also joined to a distal portion (5) of the pusher shaft (8), which is proximal to the marker band (127) that joins the connecting struts of the inner stent body (120) to the distal end of the pusher shaft (8). As shown inFIG.11B, a marker band (137) in a shape of a tube is fixed over the proximal ends of connecting struts on the outer stent body (130) to the distal portion (5) of the pusher shaft (8). As seen in the figure, the marker band (137) slides over the pusher shaft and positioned at the distal portion (5) of the pusher shaft (8), the proximal disc ends connecting struts extends beyond the proximal end of the marker band tube (137). The marker band (137) fixed over the connecting struts of the outer stent body (130) and the pusher shaft, (8) forming a mechanical lock. Now referring toFIG.12A, the exemplary inner stent body (120) of the capture device (110) has a four rows of identical cells forming a complete circumference of the body with each row having four cells. As shown in the figure, all cells have the same size, and cross-section strut profile. Each cell formed by two struts with both distal and proximal end joins together. Each strut has a wavy curvature similar to what has been described inFIG.8. Each cell has an axis forming a same angle “β1” with the longitudinal axis “L” of the inner stent body. Two cells next to each other from two adjacent rows, share a portion of the same strut. Two cells next to each other from the same row, also share a portion of the same strut.FIG.12Billustrates the inner stent body in its deployed configuration, where the inner stent body assume a pre-set generally cylindrical body with a longitudinal lumen and a distal opening. According to one embodiment, the inner stent body layer also creates an instantaneous opening of blood flow. The proximal end of the inner stent body joins to struts which is configured to attach to a delivery system (not shown). In this exemplary inner stent body embodiment shown inFIGS.12A-12B, as the inner stent body deploys, it will expand radially, axially rotate in a clock wise motion, in a sinusoidal fashion. AlthoughFIG.12Aillustrates inner stent body having identical cell size, one skilled in the art should understand that cell that made of the inner stent body could have various sizes, shapes, and orientations, similar to what has been disclosed above. For example, according to one embodiment of the present teaching, the distal portion of the inner stent body could have smaller cell size then the rest portion of the inner stent body. In another embodiment, the distal end of the inner stent body is configured to be closed in order to form a net for collecting distal embolus. AlthoughFIG.12Aillustrates the inner stent body having 4 cells per row, one skilled in the art should understand the number of cells per row could range from 3-20, depending on the size of the cell, and treatment target. Continue referring toFIG.12A, four connecting struts (121a,121b,121c, &121d) connects the proximal end of the proximal cells. The proximal ends of these four struts (121a,121b,121c, &121d) then form a mechanical connection with the distal end of the pusher shaft (8) by a marker band (127) by means as described above. By the nature of the stent design, the connecting struts portion of the inner stent body can be flexible and yield easily compared to the stent body. Thus, these connecting struts (121a,121b,121c, &121d) are configured to have a greater size, such as greater width and/or thickness, than the struts forming the cells on the inner stent body. According to one embodiment, the material mass at any axial location of the inner stent body across the entire circumference at any axial location of the inner stent body, including its connecting struts portion and stent body portion, are identical. Thus, the thickness and/or width of the struts could vary from the connecting struts portion of the inner stent body to the stent portion of the inner stent body in order to achieve this design goal. This would allow effective transfer of a physician proximal pushing strength to the entire inner stent body, and prevent kinking at the connecting portion of the inner stent body, and in turn lower the overall delivery force required. According to one embodiment of the present teaching, the strut forming each cell has a width around 0.0025″ and a thickness around 0.003″. Upon deployment, each cell has a length of 10 mm and a height of 2.5 mm to 5 mm. The angle between cell axis and the longitudinal axis “L” of the device is around 30°. In one embodiment, the inner stent body has a diameter of the stent about 2 mm to 4 mm. In one embodiment, the inner stent body is configured to rotate as the embolic capture device being deployed. In one embodiment, the speed, degree and direction of rotation of the inner stent body is programmed by the cell design. For example, the rotational rate of the inner stent body could be 90° to 720° upon complete deployment. In one embodiment, the outer stent body (130) could have a deployed diameter around 5 mm, and the inner stent body (120) could have a deployed diameter around 3 mm. Now referring toFIG.13A, the exemplary outer stent body (130) of the capture device (110) also has a four rows of identical cells forming a complete circumference of the body with each row having five cells. Similar to the exemplary inner stent body shown inFIGS.12A-12B, as shown in theFIG.13A, all cells have the same size, and cross-section strut profile. Each cell formed by two struts with both distal and proximal end joins together. Each strut has a wavy curvature similar to what has been described inFIG.8. Each cell has an axis forming a same angle “β2” with the longitudinal axis “L” of the inner stent body. Two cells next to each other from two adjacent rows, share a portion of the same strut. Two cells next to each other from the same row, also share a portion of the same strut.FIG.13Billustrates the outer stent body (130) in its deployed configuration, where the outer stent body (130) assume a pre-set generally cylindrical body with a longitudinal lumen and a distal opening. The proximal end of the outer stent body (130) joins to struts which is configured to attach to a pusher shaft. In this exemplary outer stent body embodiment shown inFIGS.13A-13B, as the outer stent body (130) deploys, it will expand radially, axially rotate in a counter clock wise motion, in a sinusoidal fashion. That is as the device deploys, its inner stent body (120) and outer stent body (130) rotates in an opposite direction. AlthoughFIG.13Aillustrates outer stent body having identical cell size, one skilled in the art should understand that cell that made of the outer stent body could have various sizes, shapes, and orientations, similar to what has been disclosed above. For example, according to one embodiment of the present teaching, the portions of the outer stent body could have smaller cell size then the rest portion of the outer stent body. AlthoughFIG.13Aillustrates the outer stent body having 4 cells per row, one skilled in the art should understand the number of cells per row could range from 3-20, depending on the size of the cell, and treatment target. In one embodiment, the number of rows as well as the number of cells per row on the outer stent body could be the same as the number of rows as well as the number of cells per row on the inner stent body. In another embodiment, the number of rows as well as the number of cells per row on the outer stent body could be different from the number of rows as well as the number of cells per row on the inner stent body. Continue referring toFIG.13A, four connecting struts (131a,131b,131c, &131d) connects the proximal end of the proximal cell. The proximal ends of these four struts (131a,131b,131c, &131d) then form a mechanical connection with a distal portion of the pusher shaft (no shown) by a marker band (not shown) by means as described above. Similar to what has been explained above, the thickness and/or width of the connecting struts (131a,131b,131c, &131d) would vary from connecting struts portion to stent body portion in order to achieve an identical material mass across the entire circumference at any axial location of the outer stent body. According to one embodiment, the distal end of the outer stent body attaches a radiopaque marker. For example, the distal end of the outer stent body could join to a marker band by crimp, weld, glue, and soldering or any other ways known in the field. In one embodiment, mark band connects to the distal end of the outer stent body in such way that it would not interfere the reentry of the device back inside the microcatheter. According to one embodiment of the present teaching, the strut forming each cell has a width around 0.0025″ and a thickness around 0.003″. Upon deployment, each cell has a length of 10 mm and a height of 2.5 mm to 5 mm. The angle between cell axis and the longitudinal axis “L” of the device is around 30°. In one embodiment, the outer stent body has a diameter of the stent about 4 mm to 6 mm. In one embodiment, the outer stent body is configured to rotate as the embolic capture device being deployed. In one embodiment, the speed, degree and direction of rotation of the outer stent body is programmed by the cell design. For example, the rotational rate of the inner stent body could be 90° to 720° upon complete deployment. In one embodiment, the outer stent body (130) could have a deployed diameter around 5 mm, and the inner stent body (120) could have a deployed diameter around 3 mm. According to one embodiment of the present teaching, during embolic capture device deployment, the outer stent body rotates in an opposite direction to the inner stent body. According to one embodiment, as the device (110) deploys at the treatment site, the inner stent body (120) radially expands and axially rotates in a clock wise motion, the outer stent body (130) radially expands and axially rotates in a counter clock motion. According to one embodiment of the present teaching, upon full deployment, the distal end of the inner stent body is configured to extend beyond the distal end of the outer stent body in both the delivery and deployment configuration of the embolic capture device. This is to prevent the inner stent body getting pinched into the outer stent body while being delivered and deployed. Thus, upon deployment, the distal end of the inner stent body (120) extends distally beyond the distal end of the outer stent body. According to some embodiments of the present teaching, the embolic capture device housed inside a distal end portion of the microcatheter reaches the treatment site. As the clinician withdraw the microcatheter proximally, the embolic capture device is exposed, and expands as programmed. As both inner and outer stent body expand radially, they also rotates to an opposite direction. The combination of both rotation motion and expanding motion create a rotational force in engaging the clot. And the opposite rotation of the two stent body layer create a pinching force to the clot. This allows the embolic capture device securely captures in the blood clot. Upon confirmation by the clinician, captured blood clot is then be retrieved back inside the microcatheter. To do so, a clinician pulls proximally on the pusher shaft. The four connecting struts (131a,131b,131c, &131d) on the outer stent body (130) first collapse radially as it extends proximal into the microcatheter, followed by the collapsing of the outer stent body (130) and the four connecting struts (121a,121b,121c, &121d) of the inner stent body, and lastly the rest of the device. As clinician continue pulls the pusher shaft (8) proximally, and the entire device collapses and enter back inside the microcatheter, the blood clot is being retrieved inside the microcatheter into a sheath. As the entire device (110) collapses and being retrieved inside the microcatheter. During retrieval process, according to one embodiment, the inner stent body (120) radially collapses and axially rotates in a counter clock wise motion, and the outer stent body (130) radially collapses and axially rotates in a clock wise motion. According to one embodiment, such multi-layer embolic capture device (110) design could improve clot engagement and retrieval. According to one embodiment, in order to minimize the retrieval force, the proximal end portion of the embolic capture device with two layers of stent body is configured that the two layers of stent body as well as their connecting struts collapses sequentially so that the retrieval (resheathing) force of the inner stent body and outer sent body are stacked and not overlapped. This design is to lower the retrieval (resheathing) force compared to having the ramp start at the same location. One skilled in the art should understand thatFIGS.11-13illustrates only one exemplary embodiment of the multi-layer embolic capture device. According to above described, especially with reference toFIG.3-10, variations to each design criteria could all be incorporated in order to program device deployment motion and achieve optimum clot capturing result. For example, by adjusting the inner and outer stent body's angles between each's cell axis and longitudinal axis “L”, the device could be programmed to have a same or a different axial rotation direction, and/or a same or a different axial movement length i.e. rotational speed. In another example, by adjusting the cell size in the inner and outer stent body, the device could be programed to have a same or a different torque strength. In another example, one of the inner and/or outer stent body could be programed to deploy in a twist rotational motion, i.e. starting with a clock wise rotation, following by a counter clock wise rotation, then following by a lock wise rotation, and etc. According to one embodiment by program the inner and outer stent body of the device with different rotation configuration, the device could further engages and captures the clot successfully. According to some embodiments of the present teaching, the inner stent body of the device could be of the same length as the outer stent body. In another embodiment, the inner stent body could be shorter than the outer stent body of the device such that the distal end of the inner stent body is proximal to the distal end of the outer stent body of the device. In an alternative embodiment, such as shown inFIG.11, the inner stent body could be longer than the outer stent body of the device such that the distal end of the inner stent body extends beyond the distal end of the outer stent body. According to one embodiment of the present teaching, upon capturing blood clot, a clinician would withdraw the device back into a microcatheter. While the retrieving the device, both inner and outer stent bodies collapses radially as the device retracing back into a sheath. In one embodiment, the inner stent body and the outer stent body axially rotate at a different speed as the device retracing back into a sheath. In another embodiment, the inner stent body and the outer stent body axially rotate at a same speed as the device retracing back into a sheath. According to some embodiment, the diameter ratio of the inner and outer stent body is 1:2 to 4:5. The expansion ratio of the outer stent body is the same as or greater than the expansion ratio of the inner stent body. Now referring toFIG.14, the pusher shaft (8) has an elongated proximal portion (202) with a constant greater diameter, a gradually tapered intermediate portion (204), and an elongated distal portion (206) with a smaller diameter. According to one embodiment, such configuration would result the pusher shaft (8) having a relative flexible distal portion for going through the tortuous path of the neurovasculature without accidentally damaging the surrounding tissue, and a relative stiff proximal portion for providing pushability to the entire length of the pusher shaft. According to one embodiment of the present teaching, the pusher shaft is made by a tapered nitinol rod with an Af transformation temperature less than 15° C. This is pre-programmed such that the nitinol rod is in its super elastic state at body temperature and at room temperature, so that the stiffness of the pusher shaft rod optimized for delivering the embolic capture device. According to one embodiment, the proximal portion (202) of the pusher shaft (8) has a diameter of 0.015 to 0.020″ and a length about 80 to 140 cm; the tapered intermediate portion (204) of the pusher shaft (8) has a length about 60 cm to 80 cm with its largest end matching the diameter of the proximal portion (202) and its smallest distal end matching the diameter of the distal portion (206) of the pusher shaft (8); and the distal portion (206) of the pusher shaft having an outer diameter of 0.005″ to 0.010″ and a length of about 5 cm to 30 cm. Continue referring toFIG.14, a coil layer (208) is fixed to the distal end portion (206) of the pusher shaft (8), extending from the distal end of the pusher shaft (8) proximally about 20 cm to 40 cm. With the coil layer (208), the distal end portion of the pusher shaft (8) is configured to maintain the flexibility of the nitinol rod while creating addition support in the pushability of the distal end portion of the pusher shaft (8). In addition, since the pusher shaft connecting to the stent body is pushing through the inside a microcatheter during delivery, the coil layer (208) is to reduce or fill the gap between the pusher shaft (8) and the microcatheter, which, as a consequence, increases the pushability as well as the torque support of the system during delivery. Because, with more gap between the microcatheter and the pusher shaft (8), the pusher shaft (8) could curve or form waves inside the microcatheter when being pushed by a physician, and the pushing force would be distracted and not be properly transformed. According to one embodiment, the coil layer (208) could be made of single or multifilar coil, with each filar size of 0.001″ to 0.002″ and a closed filar gap of less than 0.002″. It could be made of stainless steel or other materials. Since the coil layer (208) is fixed to the distal end portion of the pusher shaft (8), the coil layer (208) is configured with an inner diameter of 0.005″ to 0.010″ matching the outer diameter of the distal end portion of the pusher shaft and an outer diameter of 0.012″ to 0.015″ matching the inner diameter of the microcatheter. In one embodiment, a distal portion of the coil layer (208) could be made of radiopaque material for visibility purpose. Such material could be platinum tungsten alloy, platinum iridium alloy, or platinum. In addition, a PTFE shrink tube (210) is used to cover the coil layer (208) in order to create a smooth outer surface and thereby reduce the friction between the pusher shaft assembly and the inside surface of the microcatheter. According to some embodiments, the device is made of an elastic material, super-elastic material, or shape-memory alloy which allows said device to collapse into a generally straightened profile during the delivery process and resume and maintain its intended profile in vivo once it is deployed from the delivery catheter. In some embodiments, the device is made of stainless steel, nitinol, Titanium, Elgiloy, Vitalium, Mobilium, Ticonium, Platinore, Stellite, Tantalum, Platium, Hastelloy, CoCrNi alloys (e.g., trade name Phynox), MP35N, or CoCrMo alloys or other metallic alloys. Alternatively, in such embodiments, part or all of the device is made of any flexible, biocompatible material including, but not limited to polyester fabrics, Teflon-based materials, such as ePTFE, UHMPE, HDPE, polypropylene, polysulfone, polyurethanes, metallic materials, polyvinyl alcohol (PVA), extracellular matrix (ECM) isolated from a mammalian tissue, or other bioengineered materials, bioabsorbable polymers such as polylactic acid, polyglycolic acid, polycaprolactone, or other natural materials (e.g., collagen), or combinations of these materials that are well known to those skilled in the art. In some embodiments of the present teachings, the device can be fabricated by laser-cutting or acid-etching a pattern into a preformed tube, then shape-setting to the intended deployed configuration. In such embodiment, the cell can be formed from a hollow tube that has been slotted using, for example, a machining laser or water drill or other method and then expanded to form the open structure. In another embodiment of the present teachings, the mesh can be formed from wire that is pre-bent into the desired shape and then bonded together to connect elements either by welding them or adhesively bonding them. They could be welded using a resistance welding technique or an arc welding technique, preferably while in an inert gas environment and with cooling control to control the grain structure in and around the weld site. These joints can be conditioned after the welding procedure to reduce grain size using coining or upset forging to optimize fatigue performance. According to one embodiment of the present teachings, the device is fabricated from a tube and then shaped to its final configuration. In one embodiment, if a sufficiently elastic and resilient material such as nitinol, is used, the structure can be preformed into the finished shape and then elastically deformed and stowed during delivery so the shape will be elastically recovered after deployment. One skilled in the art will recognize that the device described herein may be used in conjunction with infusing medication through the catheter directly into the thrombus site. Those embodiments with a distal net could limit the medicine, such as tPA (tissue plasminogen activator) that works to dissolve the clot, to be local and directly apply onto the blood clot. Specifically, the distal net of the device creates a closed volume which prevents the tPA from circulating through the system. Since this design also has a function of blocking the blood flow, it prevents blood from further bleeding, injection of medicine, and aspirating the blood out of tissues. For example, the pusher shaft could be configured to excrete tPA or any treatment medication. Those embodiments with a distal net, the space between the stent body and net, or two caps, is configured to create a closed contour which prevents the tPA from circulating systemically. In such event, after a certain amount of time, the emboli will be dissolved with the medicine, by aspiration, and/or retrieved by embolic capture device. This exemplary embodiment provides an emboli engaging device that could perform thrombectomy without the help of a microcatheter. As such, using the embodiments of the present teachings can reduce vessel traumas, improve effectiveness in tortuosity, increase procedural success rate, and reduce the likelihood of losing the clot in tortuosity. According to one embodiment of the present teachings, a radiopaque marker, coil or wire is winded to the elongated body to make the embolic capture device visible using radiographic imaging equipment such as X-ray, magnetic resonance, ultrasound or other imaging techniques. Markers as disclosed herein may be applied to the ends of any part of the devices, or even on the delivery system of the device. A radiopaque marker can be sewed, adhered, swaged riveted, otherwise placed and secured on the device, The radiopaque marker may be formed of tantalum, tungsten, platinum, iridium, gold, alloys of these materials or other materials that are known to those skilled in the art. The radiopaque marker can also be cobalt, fluorine or numerous other paramagnetic materials or other MR visible materials that are known to those skilled in the arts. In addition, the delivery system could also be designed for aspiration purpose. For example, the pusher shaft is configured with an aspiration chamber. Such chamber is configured to open for aspiration. Upon delivery the distal end of the pusher shaft to the treatment location, the physician will be able to connect the aspiration pump, or a syringe, to the Pull Hypotube and suck in the clot. In some embodiments, the surface of the pusher shaft with the aspiration chamber is moderated to increase the aspiration effectiveness. Various embodiments have been illustrated and described herein by way of examples, and one of ordinary skill in the art will appreciate that variations can be made without departing from the spirit and scope of the present teachings. The present teachings are capable of other embodiments or of being practiced or carried out in various other ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this present teachings belong. Methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present teachings. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.

11857210

DETAILED DESCRIPTION Specific embodiments of the present invention are now described in detail with reference to the Figures, wherein identical reference numbers indicate identical or functionality similar elements. The terms “distal” or “proximal” are used in the following description with respect to a position or direction relative to the treating physician. “Distal” or “distally” are a position distant from or in a direction away from the physician. “Proximal” or “proximally” or “proximate” are a position near or in a direction toward the physician. Accessing cerebral, coronary and pulmonary vessels involves the use of a number of commercially available products and conventional procedural steps. Access products such as guidewires, guide catheters, angiographic catheters and microcatheters are described elsewhere and are regularly used in cath lab procedures. It is assumed in the descriptions below that these products and methods are employed in conjunction with the device and methods of this invention and do not need to be described in detail. The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Although the description of the invention is in many cases in the context of treatment of intracranial arteries, the invention may also be used in other body passageways as previously described. The expandable members of the designs disclosed are desirably made from a material capable of recovering its shape automatically once released from a highly strained delivery configuration. A superelastic material such as Nitinol or an alloy of similar properties is particularly suitable. The material could be in many forms such as wire or strip or sheet or tube. A particularly suitable manufacturing process is to laser cut a Nitinol tube and then heat set and electropolish the resultant structure to create a framework of struts and connecting elements. This framework can be any of a huge range of shapes as disclosed herein and may be rendered visible under fluoroscopy through the addition of alloying elements (such as Platinum for example) or through a variety of other coatings or marker bands. Compression of the clot can alter the clot properties and make the clot less amenable to retrieval by making it firmer and “stickier” as described in our WO2012/120490A, the entire contents of which are herein incorporated by reference. The device of this invention is intended to facilitate clot retrieval by expanding between the clot and the vessel wall in such a way as to engage with the clot over a significant surface area, and do so with minimal compression of the clot. The overall clot compression is minimized because the device is constructed to have rings of high compression with deep strut embedding interspersed with areas of minimal clot compression. A portion of clot can protrude into the area of low compression and can be pinched between the tip of a catheter and the nitinol struts of the device. The pinch is achieved by forwarding a microcatheter or intermediate catheter over the device until a portion of clot is compressed between the tip of the catheter and a crown or strut on the device. This pinch facilitates removal of the clot as it increases the grip of the device on the clot, particularly fibrin rich clots. It may also elongate the clot reducing the dislodgement force by pulling the clot away from the vessel wall during the dislodgement process. It potentially improves retention of the clot during retraction to the access guide catheter or sheath by controlling the proximal end of the clot and preventing it from snagging on a side branch vessel. The device design to facilitate pinching of an occlusive clot detailed in this invention can be incorporated into the full length of the device or more typically in the proximal 30%-50% of the length of the device. The diameter of this pinch segment can vary from 30% to 150% of the diameter of the target vessel at the position of the occlusive clot, but in the preferred embodiment for the middle cerebral artery, it is more typically 50% to 100% of the target vessel diameter. This invention details how the clot pinch can be generated between the microcatheter tip and struts or crowns on a single tubular structure or alternatively the clot can be pinched between the catheter tip and the struts on the outer cage or inner channel of an assembly. The inner channel of the invention may also comprise a portion that compresses an area of the clot in order to form a blood communication channel across the clot. Such a channel serves two key purposes: 1) it reduces the pressure gradient across the clot, thus reducing one of the forces that must be overcome in order to retract the clot and 2) it provides a flow path for oxygenated, nutrient carrying blood to reach the ischemic area distal of the clot. All of the devices described herein may also comprise a distal fragment capture portion, such as illustrated inFIGS.7,8,9,10,11, and12. This portion is ideally deployed distal of the clot to prevent the distal migration of any clot fragments that might be liberated during retrieval. FIGS.1a-1eshow a method of use of a device of this invention. A guidewire102and microcatheter103are inserted in the vasculature100and are advanced across the obstructive clot101using conventionally known techniques. When the microcatheter103is positioned distal to the occlusive clot101, the guidewire102is removed from the vasculature100to allow the clot retrieval device110be advanced through the microcatheter. The device110is advanced in a collapsed configuration until the distal tip of the device reaches the distal end of the microcatheter103. The microcatheter is retracted while the position of device110is maintained to deploy the clot retrieval device across the clot101in a manner that the distal end of the device is preferably positioned distal of the clot101(FIG.1b). The device110consists of a clot engagement portion112connected to an elongated proximal shaft portion111. The device110expands so that it engages with the occlusive clot at the proximal end or along its length. The device has segments that have low levels of scaffolding and do not compress the clot but allow the clot to protrude into these low radial force areas. The device110may be allowed to incubate for a period of time within the clot101if desired. Prior to retracting the device, the microcatheter can be forwarded distally to pinch a portion of the clot between the tip of the microcatheter and the struts and crowns of the device adjacent to the low radial force area. This pinch provides additional grip and control of the proximal end of the clot during dislodgement and retention back to the access guide catheter or introducer sheath (FIG.1e). The relative tension between the device and the microcatheter is maintained by the user during dislodgment and retraction to ensure the pinch on the clot is maintained. While the use of a microcatheter or intermediate catheter to pinch the clot is described as giving additional benefits when used with this invention, all the embodiments described herein can also be used to dislodge and retrieve clots without the use of catheter pinching if required. Flow arrest in the vessel may be utilized by inflating a balloon (not shown) on the guide catheter as per standard technique.FIG.1eillustrates the clot engaged with the device during retrieval into the guide catheter104. Flow occlusion, aspiration and other standard techniques may be used during the clot retrieval process. The device110may be rinsed in saline and gently cleaned before reloading in the insertion tool. The device110may be reintroduced into the microcatheter to be redeployed in additional segments of occlusive clot, if required. FIGS.2a-2cshow the proximal end of one embodiment of the device illustrated inFIGS.1a-1e. The device is typically formed from a material with “Superelastic” properties such as nitinol and can be laser cut and expanded from a tube or flat sheet raw material. The self-expanding section of the device130is connected to a proximal elongated shaft131. The device of this invention is designed to create a clot pinch and generate additional grip between the device130and the clot135. The device130is constructed so that it consists of rings of struts134which have an adequate radial force to provide good clot embedding, interspersed with areas of low scaffolding and low radial force132. The longitudinal distance between the rings of struts can vary from 2 mm to 8 mm, but in the preferred embodiment for use in the middle cerebral artery the longitudinal spacing is 3-6 mm. While the struts134embed and provide some scaffolding of the clot, the area with low scaffolding132allows the clot136to protrude into this area. After an incubation time, if desired, of typically 1 to 5 minutes, the microcatheter140(used to introduce the device or an alternative microcatheter) can be advanced to pinch the protruding clot136between the tip of the microcatheter144and the struts and crown142of device130. The struts134achieve good embedding in the clot as the freely expanded diameter of these struts can vary from 30% to 150% of the diameter of the target vessel at the position of the occlusive clot, but in the preferred embodiment is 50% to 100% of the target vessel diameter. In the embodiment shown the connecting struts133between the rings of struts134are curved with a reduced diameter towards the mid-section of the strut to minimize the radial force and scaffolding. This feature can also be seen inFIGS.3aand3b. Further distal advancement of the microcatheter140relative to the device130will further compress the clot141between the catheter tip144and the struts of the device142increasing the pinch on the clot (FIG.2c) and the security of the trapped clot segment136. The user may feel this pinch as a resistance and stop advancing the microcatheter, or alternatively the user may advance the microcatheter a fixed distance over the device (for example 30% to 50% of the device length) before retracting the device and microcatheter together. The relative tension between the device130and the microcatheter140needs to be maintained to ensure the pinch between the device and clot does not deteriorate. By retracting the device130and the microcatheter140together, the occlusive clot can be dislodged and retracted back into the access guide catheter or introducer sheath and be removed from the patient. This invention is particularly suited to the dislodgement and retraction of clots which have a high fibrin content (typically higher than 40% fibrin content) and other clots which are difficult to dislodge and retrieve with known stent retriever designs and currently may require multiple passes to remove the clot from the vasculature. This invention may also create a clot pinch by advancing an intermediate catheter in the same manner as described here for the microcatheter140. FIG.3ashows an isometric view of another embodiment of the device. In this configuration the embedding section of the device consists of a ring of cells151. This ring151consists of 3 circumferential cells in this embodiment. The number of cells in the circumferential ring can vary from 2 to 5, but in the preferred embodiment is 3 or 4 cells. As with the device shown inFIGS.2a-2c, the portions of the device152between the embedding cells section have low radial force and a low level of scaffolding. The low level of scaffolding is achieved by minimizing the potential surface contact area between the device struts and the clot in this area152. In this embodiment the connecting struts153are curved towards the centerline of the device at the mid-point to further reduce the strut contact force and area with the clot. This low surface contact area and radial force allows the clot to protrude into this section of the device when it is deployed in an occlusive clot. Partial resheathing of the device with a microcatheter or intermediate catheter can then pinch this protruding clot between the tip of the catheter and the proximal struts154of the embedding ring of cells. FIG.3bshows a side view of the device illustrated inFIG.3awith a corresponding graph of radial force plotted against device length. The dotted lines155and157show how the rings of cells that embed in the clot have a higher radial force compared with the sections152between the rings. Dotted line156indicates the reduced radial force of this section. FIG.3cillustrates the outward radial force profile of three devices of this invention similar to device150ofFIG.3a, when constrained in a lumen of less than 50% of their freely expanded diameters. All three exhibit the generally sinusoidal pattern described previously, but the magnitude (or amplitude) of the radial force peaks and troughs varies along the length of these devices. Profile50represents a radial force profile that tapers up along the length of the device, with the radial force of the first peak51being lower than that of subsequent peaks52-54. Profile represents a radial force profile that tapers down along the length of the device, with the radial force of the first peak61being higher than that of subsequent peaks62-64. Profile70represents a radial force profile that tapers up and then down along the length of the device, with the radial force of the first peak71being lower than that of the second peak72, but the radial force of the last peak74being lower than that of the second from last peak73. FIG.3dillustrates what radial force profile70could look like if the device were constrained instead in a lumen of more than 50% of its freely expanded diameter (80% for example). In this case we see that the device exerts no outward radial force whatsoever on its constraining lumen in areas either side of the three peaks81,82,83shown. Thus the device is maintaining its grip on the clot in the area of the peaks, while exerting minimal compression on the clot in the areas between the peaks, which helps to minimize the force required to retract the clot, and thus increases the likelihood of a successful clot retrieval. TheFIGS.3cand3dalso represent the radial pressure of the strut elements of these three different devices. Radial pressure differs from radial force in that it refers to the force per unit area exerted by the device. Thus if two devices have the same radial force over a given area, and one device has a lower strut surface area than the other in that given area, then the device with the lower strut surface area will exert a higher radial pressure. This is very important for clot grip because radial pressure is what enables a strut to embed itself into the clot material—somewhat akin to the difference between a stiletto heel and an elephant's foot: when standing on soft sand the stiletto heel will sink deeply into the sand while the elephant's foot will not sink as deeply in. For a given level of radial force, the radial pressure of a device can thus be increased by reducing the strut surface area, which can be done by reducing strut width or number of struts. The effectiveness of this increased radial pressure at clot gripping can be further increased by maximizing the angle of the struts to the longitudinal axis of the vessel. The greater the angle of the strut the greater the ability of the strut to grip the clot rather than slide past it. Ideally the strut would approach a 90 degree angle with the vessel axis for optimum grip, but this can be difficult to achieve in practice for a number of reasons. One major reason for this is the fact that the device is typically expanded to only a fraction of its freely expanded diameter when deployed under the clot initially. This is because it is advantageous for the device to be able to expand to a large diameter as it is retracted so that it can retain its grip on the clot and remain in contact with the vessel wall as it is retracted into larger more proximal vessels. The inventors have discovered an effective solution to this problem: namely a two stage diameter device as shown in various FIGS. throughout this disclosure, such as for exampleFIG.7a. The proximal smaller diameter can be used to embed struts firmly in the clot for a secure grip at a steep opening angle, while the larger diameter distal section can expand to remain in contact with the vessel wall and protect against distal migration of the clot as it is retracted into larger vessels. This configuration enables strut angles of the proximal section to be larger than 30 degrees, or preferably larger than 45 degrees or even more preferably as large as 60 degrees to the vessel axis.FIG.7dillustrates this point in greater detail. FIGS.4ato4eshow another embodiment of the device formed from a flat sheet.FIG.4ashows a plan view of the device160which in this embodiment is formed of two rows of cells162bounded by sinusoidal edges165and connected by cross struts164. The device is connected to a proximal shaft161.FIG.4bshows an isometric type view of the device160deployed in an occlusive clot174which is located in a vessel170. A cut away view of the vessel170has been provided for clarity. A microcatheter172is shown positioned on the proximal shaft with the tip of the microcatheter located at the joint between the clot engagement section of the device and the shaft. Where the clot174is in contact with the device160, portions of clot171protrude through the cells.FIG.4cshows a cross section view of the vessel180, including the clot183and the device182. This view illustrates the clot protruding through the cells of the device181. FIG.4dis a magnified view of the proximal end of the device206showing how the clot is pinched as the microcatheter200is forwarded to partially resheath the device in the cut away vessel204. The protruding portion of the clot210is trapped between the struts of the device and the microcatheter200.FIG.4eshows the device206and the microcatheter200being retracted at the same time, dislodging the body of the clot205from the vessel204, due to the pinched grip on the protruding piece of clot211. FIGS.5a-5dshow an alternative tubular embodiment of the device of the invention.FIGS.5a-5dshow a side view, end view, plan and isometric view of device230. This device has alternating rings of embedding struts231with low radial force segments232, along its length. The preferred embodiment contains between 4 and 8 struts in a radial pattern for optimum embedding in the clot. The connecting struts233in section232in this embodiment are straight for optimum pushability to ensure the device can be delivered through tortuous anatomy. FIGS.6a-6dshow another embodiment of the invention.FIGS.6a-6dshow a side view, plan, end view and isometric view of device240. This device has alternating rings of embedding cells241with low radial force segments242. The preferred embodiment contains between 2 and 4 cells in a radial pattern for optimum embedding in the clot. The use of a ring of cells instead of a ring of struts in this embodiment may improve clot pinching as the distal ring of struts244in each segment stays expanded for longer even as the more proximal ring of struts245is wrapped down by the microcatheter as it advances. This maintains strut embedding in the clot for longer improving the pinch of the clot between the struts and the microcatheter. FIGS.7a-7dillustrate an embodiment which consists of an assembly of an outer cage and an inner component. In this embodiment the proximal part256of the outer component250is designed to pinch clot in the same manner as described forFIGS.1and2and contains alternating segments of cells251for embedding in the clot, and segments252of low radial force and low scaffolding. This proximal part256of the outer component is joined to a body section255which has an increased diameter and larger cells253for additional clot retention as it is retrieved into larger vessel diameters in the Internal carotid Artery before retraction of the device and clot into the access guide catheter or introducer sheath. The ratio of the body section255diameter to the proximal section diameter can vary from 1.5:1 to 4:1, and in the preferred embodiment is between 2:1 and 3:1. FIG.7bshows the inner component260of the assembly. This component contains an elongated proximal strut261which connects the body section262to the shaft (not shown). The component260also contains a fragment protection structure263and a distal atraumatic tip264.FIG.7cshows how the two components are aligned in the assembly270. The elongated proximal strut273is positioned under the proximal part of the outer cage277so that there is minimal restriction to clot protrusion into the low radial force segments. The body section of the inner component274is positioned in the body section of the outer component271and provides a flow channel to break the pressure gradient across the clot and provide flow restoration. The distal fragment protection structure275sits inside the end of the outer cage which has an open end272and provides protection against the loss of clot fragments and emboli.FIG.7dshows an isometric view of this assembly270. FIG.7eshows device250deployed within a clot258in a vessel259, illustrating a key advantage of a stepped diameter design such as that of the clot engaging element250ofFIG.7a. The relatively high radial force and radial pressure of the struts of the proximal section256allow the struts251of the section to embed deeply into the clot, creating clot bulges257which can subsequently be pinched within cells252by the advancement of a microcatheter (not shown). In addition the smaller freely expanded diameter of the proximal section256means that the struts251of this section are inclined at a much steeper angle than those of the distal section255, which enables them to much more effectively grip the clot for secure retraction. The description in relation toFIGS.3dand3edescribes the significance of these strut angles in more detail. FIG.8shows another configuration280of the assembly shown inFIG.7where the fragment protection structure283connected to the inner component285is positioned distal of the end of the outer cage282. Ensuring there is a gap between the end of the outer cage286and the fragment protection structure283may improve the fragment protection performance particularly as the device is retracted in tortuous vessels. It may also be beneficial as the device is retrieved into a catheter as the fragment protection zone283will still be fully expanded and provide protection as the outer cage is fully retrieved. FIG.9is a side view of another outer cage configuration330where the proximal part335of the component is designed to pinch the clot as described inFIG.7, when a catheter is forwarded distally. In this configuration the component330also contains a body section332for clot retention during retrieval and also a distal fragment zone334.FIG.10shows an assembly340of the outer cage342described inFIG.9and an inner channel344. The inner channel344in this assembly340runs the full length of the outer cage342including under the proximal section341. FIG.11shows an inner component360which consists of a body section362and a proximal section364which contains alternating segments of embedding cells361and low scaffolded areas363to promote clot protrusion and clot pinching.FIG.12illustrates how this inner channel design373can be integrated in an assembly370with an outer cage372. The outer cage372has extended proximal struts375to minimize any obstructions to the clot engaging with the proximal section371of the inner component. FIG.13shows another embodiment of the invention400consisting of an assembly of an outer cage402and an inner channel408. These two components are connected to a proximal shaft401and a distal radiopaque tip405. In this embodiment the inner channel408is designed to facilitate clot pinching as described elsewhere in this specification by having alternate rings of struts407for deep embedding in the clot, adjacent to areas of low strut density or scaffolding406. As this inner component408is positioned inside of the outer cage402, there is the potential for the struts of the outer cage to obstruct clot embedding and protrusion in the inner channel408. To eliminate this issue, the outer cage402is designed so that the struts of the outer cage align with the struts of the inner channel408, when the outer cage is partially expanded to the same diameter as the freely expanded inner channel. FIGS.14aand14bshow a segment420of the outer cage illustrated inFIG.13. The segment420is shown expanded to a diameter greater than the freely expanded diameter of the inner channel but below the freely expanded diameter of the outer cage inFIG.14a. The ‘dog-leg’ shape of the strut421can be seen in the image and this shape strut is repeated around the circumference and along the length to form cells425.FIG.14bshows how the strut shape consists of a short segment423connected to a longer segment424at an angle (A) as shown. This angle can vary from 20.degree. to 90.degree. and in the preferred embodiment is 30.degree. to 60.degree. The short segment of strut423may also have an increased strut width compared to the longer segment424. In this configuration the short strut segment423has a higher expansion force than the longer strut segment424therefore it will have preferential expansion and the crown426will open before the crown427expands. This gives the outer cage a two stage expansion process with struts423and crown426fully expanding before the struts424and crown427expand. This two stage expansion process also results in a radial force profile that reduces when the first stage expansion is complete. This strut configuration can be produced by laser cutting this strut profile form a nitinol tube which has a diameter equal to or greater than the first stage expansion diameter. Alternatively the part can be laser cut from a smaller tube and the struts constrained in this shape during heat-setting. FIG.15shows the same outer cage segment asFIG.14. In this image however the segment430is at the same diameter as the freely expanded inner channel. This is the same diameter as the end of the first stage expansion step when struts432are fully expanded but struts434are still collapsed.FIG.16shows the segment of the inner channel which aligns with the outer cage segment illustrated inFIGS.14and15. As discussed inFIG.13this segment440contains rings of struts442and areas of low radial force and strut density444. FIG.17shows the outer cage segment452(described inFIG.15) overlapping the inner channel segment453(described inFIG.16). The benefit of this design is that the struts of both segments fully align as shown, so there is no obstruction to the strut section450embedding in the clot. Similarly there is no obstruction to the clot protruding into cell area451, thereby facilitating a pinch when the microcatheter is forwarded distally. In addition as the device is retracted proximally towards the guide catheter or sheath, the outer cage can continue to expand and maintain contact with the clot even as the vessel diameter increases. FIG.18shows a cell pattern470beneficial to clot pinching. This pattern470can be incorporated in a tubular or flat device configuration. When deployed across an occlusive clot in the vasculature, clot protrusion occurs in the large cell area473. After a suitable incubation time, the microcatheter can be advanced from the proximal side472to partially resheath the device. When the microcatheter contacts the clot protruding into cell473it forces the clot to move distally in the cell into area474between the struts471. The narrowing struts channel the trapped clot towards crown475creating an improved pinch on the clot between the catheter tip and the device. FIG.19illustrates a configuration of the invention that consists of an assembly470of multiple tubular components connected in parallel. In the configuration shown two components472and473are connected at the proximal end by a strut474and subsequently to the proximal shaft471. Both the components shown here,472and473, are similar to the embodiments described inFIGS.3and6. The alignment of these components may be staggered as shown in this image and the components may twist around each other along the length. More than two components may be connected together in this manner and the different components may have different diameters or be tapered along the length. The assembly of these components has the potential to improve clot pinching and grip when the device is partially resheathed with a microcatheter or intermediate catheter. FIG.20ashows a configuration of the device where the tubular component480is formed into a helical or spiral shape482and is connected to a proximal shaft481. The cut pattern of the component483is designed to promote clot embedding and grip as described inFIGS.3and6. However in this configuration, the centerline of the component follows a helical track such as that shown inFIG.20b, where the track491follows the surface of a cylindrical mandrel490. In another embodiment of the device shown inFIG.21, a flat device500is formed so that the centerline of the device also forms a helical path in this case. This device can be formed by laser cutting the required strut pattern502from a tube or by cutting a flat sheet and then wrapping the flat part around a cylinder prior to heat-setting. Therefore the device has a similar shape to wrapping a wide ribbon around a cylinder. When this device is deployed across as occlusive clot, the clot can protrude into the areas of low strut density but also into the central lumen of the helical coils. On device retraction this can improve clot grip and dislodgement performance and can also facilitate clot pinching if a microcatheter or intermediate catheter is forwarded distally over the device until it contacts the clot. The embodiment500shown has a flat cross section in the body part506of the device. The helical body section is connected to a proximal shaft501and a distal fragment protection structure503with a distal tip504.FIG.22shows another device embodiment520similar toFIG.21except with a curved or profiled cross section shape for the body segment522.FIGS.23a-23cillustrate different examples of cross section shapes that may be incorporated in this configuration of the invention.FIG.23ashows a flat cross section531,FIG.23bshows an shaped cross section532andFIG.23cshows a curved cross section533. FIG.24ashows another helical configuration of the device550with a curved cross section similar to that shown inFIG.23c. The laser cut or wire formed clot engagement section553is connected to a proximal shaft551. A microcatheter can be used with this device to pinch the clot and generate improved grip on the clot as described inFIG.1. When the micro or intermediate catheter is forwarded over the device to pinch the clot it can follow the centerline of the vessel or alternatively it can follow the centerline of the device and follow a helical track as shown inFIG.24b. If the catheter561follows the centerline of the vessel562during resheathing it can generate good pinching of the clot in the luminal space564within the helical coil. Alternatively if the catheter561follows the centerline of the device563as shown, it can generate good pinching of the clot in the cells of the cut pattern560.FIG.25shows an embodiment of the device580that is constructed from two helical components583and584to form a double helix type construction. FIG.26illustrates another embodiment of the invention600where the proximal part of the device601is designed to facilitate clot pinching if required, similar to that described inFIG.7. The body section604is also similar to that described inFIG.7, however in this embodiment the connection603between the proximal and body sections can elongate under tension. This facilitates the stretching of the clot during dislodgement by the device. The proximal end of the clot will be pinched and constrained on the proximal part of the device601while the distal end of the clot will be positioned on the body section604. When the device is retracted the proximal end601will move first pulling the proximal end of the clot. If the distal end of the clot is stuck in the vessel, the body section of the device will remain static and the connector603will elongate. This will also elongate the clot peeling it from the vessel wall and reducing the dislodgement force. When the tension in the connector603equals the dislodgement force of the distal section of the clot the remainder of the clot will start moving. In this embodiment the elongating connector603is formed of a coil spring, however in another embodiment this elongating element could form part of the cut pattern of the outer cage. FIGS.27aand27billustrate another embodiment of the device.FIG.27ashows the device700in the freely expanded configuration. In this iteration of the invention the proximal part of the outer cage701is configured to promote clot embedding and clot protrusion to facilitate clot pinching. The body section702of the outer cage has an increased diameter compared to the proximal section, to ensure good clot retention as the device is retracted past bends and branches in the vasculature. The outer cage has an open distal end with radiopaque markers703shown on the distal crowns. The inner component in this assembly consists of a wire706connecting the fragment protection structure705with the proximal joint708. In the freely expanded configuration there is distinct gap between the distal struts of the outer cage703and the leading edge of the fragment protection structure707. This gap can vary from 1 mm to 20 mm and in the preferred embodiment will range from 5-10 mm. FIG.27bshows the same device asFIG.27aexcept in this image the device750is at the diameter of the target vessel at the location of the occlusive clot. At this diameter the leading edge757of the fragment protection structure755is located inside the outer cage752and proximal of the distal crowns753. This change in position of the fragment protection structure755relative to the outer cage752is due to the length differential of the outer cage752in the freely expanded configuration and at reduced diameters. Positioning the fragment protection structure inside the outer cage at small diameters minimizes the parking space required distal of the clot for device deployment. In addition, positioning the fragment protection structure755distal of the outer cage752during device retraction in large vessels and during retrieval into a guide or intermediate catheter improves the efficacy of the fragment protection. FIG.28shows a method of use of the device embodiment described inFIG.27. Device800is deployed across the clot803using standard interventional techniques and positioned so that the distal end of the device802and fragment protection structure801is positioned distal of the clot803. The device800also contains a clot pinch portion804and is connected to an elongated proximal shaft portion805. Device image850shows the device in the vessel after the microcatheter855has been advanced to generate a pinch between the clot853and the proximal portion of the device854. At this diameter in the target vessel location, the distal fragment protection structure851is partially inside the outer cage852. Device image900shows the device as it is retracted back into a larger diameter vessel. As the vessel diameter increases, the diameter of the outer cage901also increases and the outer cage length shortens. This creates a gap between the proximal edge902of the fragment protection structure and the distal end of the outer cage905. This facilitates the capture of any fragments or emboli904liberated during the dislodgement and retrieval process. The clot906is still held pinched between the distal tip of the microcatheter907and the device908. Device image950also illustrates the effectiveness of the fragment protection structure951as it captures the clot fragments954and953released from the clot body956during the retrieval process. The device1000shown inFIG.29is another embodiment of the device shown inFIGS.20aand20bwhere a tubular component1001is formed in a helical or spiral configuration and connected to a proximal shaft1002. In this configuration the centerline of the component forms a helical track which follows the surface of a tapered or cylindrical mandrel as shown inFIG.20b. The diameter of the tubular component can vary from 0.5 to 8.0 mm and in the preferred embodiment ranges from 1.0 to 4.0 mm. The diameter of the cylindrical mandrel that the helix track follows can vary from 1.0 to 10.0 mm and in the preferred embodiment ranges from 2.0 to 7.0 mm. The pitch of the helix can vary from 3.0 to 30 mm and in the preferred embodiment ranges from 10.0 mm to 20.0 mm. The helical configuration of this device provides performance benefits for clot dislodgement as the device engages more with the clot than for a straight configuration. The clot embeds deeper in the cells and between the struts of the device improving the grip of the device on the clot. This occurs due to the helical shape which positions portions of the device away from the surface of the vessel and in the body of the clot. This is shown inFIG.30where the spiral device1051is deployed within the clot1052in the neurovascular vessels1050. The device1051is deployed as per standard procedure for deploying a stent retriever, by delivering it through and then retracting the microcatheter1053. In one method of use, the device1051can be retracted directly to dislodge the clot1052and retrieve it into the access catheter1054. Aspiration may be utilized during the procedure and flow arrest may be provided by inflating the balloon1055on the access catheter1054. Alternatively, after deployment of the device1051in the clot, the microcatheter1053can be forwarded again to partially resheath the device1051and generate a pinch on the clot between the distal tip of the microcatheter and the struts and crowns of the device1051as described elsewhere in this specification. The device, microcatheter and clot can then be retracted as a unit into the access catheter, utilizing flow arrest and aspiration, if required. The increased depth of clot embedding in a device with a helical or corkscrew configuration is particularly useful for obtaining a pinch on clots in difficult vessel tortuosity and in vessel bifurcations as shown inFIG.31where the effective diameter of the bifurcation (D4) is larger than the diameter of the proximal (D1) or distal (D2, D3) vessels. This is further illustrated inFIGS.32aandb, whereFIG.32aillustrates a straight tubular component1071deployed in a clot1072within a vessel1070.FIG.32bshows improved engagement and embedding in the clot1082when the tubular component1083(with the same diameter as component1071inFIG.32a) is formed with a helical configuration. The helical configuration increases the depth the device1083engages within the clot and also the surface area of the device in contact with the clot. FIG.33shows a helical tubular component1102deployed in a clot1101which is located in a bifurcation of the anatomical vessels1100. The microcatheter1103can be forwarded to resheath the device1102until the physician feels a resistance to movement indicating that the clot has been pinched in the device. The microcatheter1103, device1102and clot1101can then be removed simultaneously while maintaining the pinch between the device and clot. The helical tubular component shown inFIGS.29to33is particularly good at generating a pinch on clots which are difficult to dislodge and retrieve from the vessel such as organized clots with a moderate to high fibrin content.FIG.34shows a device1200which can be used for dislodgement and retention of all clot types. This device1200incorporates a helical tubular component1205which can be used to generate a pinch on the clot by partial resheathing with the microcatheter as described previously. The outer cage component1201also engages with the clot on deployment providing additional grip for dislodgement and retention of the clot as the device is retracted proximally to the intermediate catheter, guide catheter or sheath. The outer cage component1201provides dislodgement and retention capability for a full range of clot types including soft erythrocyte rich clots and hybrid clots with varying elements. The helical component1205also provides additional radial force to the inner surface of the outer cage1201helping it to expand within the clot on deployment. The outer cage component1201has distal radiopaque markers1204to mark the distal end of the component under fluoroscopy. The radiopaque markers1204would typically consist of wire coils, rivets or inserts produced from Platinum, Tungsten, Gold or a similar radiopaque element. The outer cage1201is connected to the proximal shaft1210in this configuration by a proximal strut1209. This strut1209has minimal impact on the pinch performance of the helical component1205and can be positioned inside or outside of the proximal section of the helical tube1207. To generate a pinch on the clot with this device, it can be partially resheathed with a microcatheter, diagnostic or intermediate catheter until the physician feels a resistance to pushing the catheter any further distal over the device. At this point the physician knows he has a successful pinch and the catheter and device can be removed with the clot as a unit. If no resistance is felt or a pinch is not generated then the device1200can be retrieved as a standard stent retriever to retrieve the clot to the access catheter. The radiopaque marker1206is visible under fluoroscopy and is an indicator to the physician on when to retrieve the device as a standard stent retriever, i.e. resheath the device with the microcatheter (not shown) until a definite resistance (pinch) is felt or until the tip of the microcatheter is aligned with marker1206. Then retrieve the device as per standard procedure. This device1200also incorporates a fragment protection feature1202to capture clot fragments or emboli that may be generated during the clot dislodgement and retrieval. In this configuration the fragment protection feature1202is an integral part of the helical component1205and is positioned distal to the outer cage component1201when fully expanded. A distal radiopaque tip1203is connected to the end of the fragment protection feature1202. For additional clarity the outer cage component1201and helical component1205shown in the device assembly1200inFIG.34are illustrated separately inFIGS.35aand35b. The outer cage component1250inFIG.35ahas a mid-section construction in this configuration similar to that described in our WO2014/139845A, the entire contents of which are incorporated herein by reference. Distal markers1252are connected to the distal crowns of this section for visibility under fluoroscopy and radiopaque marker1253is positioned on the elongated proximal strut1254. The radiopaque marker1253can be formed from a coil of radiopaque material and can be bonded, welded or soldered in place. Alternatively it can be formed from a ring of radiopaque material and be radially crimped, or formed from a flat sheet and be riveted in an eyelet on the strut. The proximal collar1255can be used to assemble the outer cage component1250and the helical tube component1300(shown inFIG.35b) to the proximal shaft of the device (not shown). FIG.35billustrates the helical component1300that is included in the assembly1200inFIG.34. For clarity no strut details are shown along the body section1302of the component1300in this image. Proximal struts1305and the proximal collar1301used for device assembly are shown. The fragment protection section1303and the distal radiopaque marker1304are also shown. In this configuration the body section1302has a fixed diameter along its length, however in other configurations (not shown) the diameter may increase or decrease along the length. Similarly in other configurations the helical diameter and pitch may vary along the length or the component may have a combination of straight and helical sections. In addition to the pinch capability of this component, it also provides inner channel functionality such as; immediate restoration of blood flow on deployment, breaking the pressure gradient across the clot, facilitating contrast flow and distal visualization and acting as an aspiration channel for distal emboli. The strut and crown pattern of the device1300may vary along the length of the body section1302so that the proximal portion provides a pinch capability while the mid and distal portions are more densely scaffolded to provide inner channel functionality. Another embodiment of the invention is shown inFIG.36. This device1400is also an assembly of an inner helical tubular component1403and an outer cage1401. In this configuration the fragment protection feature1406is integral to the outer cage1401. The outer cage1401and the helical component1403are connected to the proximal shaft1404at the proximal joint1405. The distal radiopaque tip1402is joined to the outer cage1401in this assembly. FIG.37shows another embodiment of the device shown inFIG.7a. In this device1450, the proximal section1451is configured to pinch the clot when partially resheathed by the microcatheter. As before the proximal struts1456have large opening angles and the cell size promotes clot protrusion to facilitate pinching between the microcatheter and the device1450during resheathing. The mid-section1452is configured to expand to a larger diameter than the proximal section to provide clot grip and retention during retraction of the clot past vessel bends and branches. The proximal1451and mid sections1452have different strut lengths and cut patterns and hence different radial force characteristics. In one embodiment the radial force of the proximal section1454is larger than the corresponding radial force of the mid-section1455, for a fixed deployment diameter (e.g. 1.0 mm), while in another embodiment the radial force of the mid-section1452is larger than the radial force of the proximal section1451for the same deployment diameter. FIG.38illustrates a typical strut cut pattern of the pinch portion of any of the devices detailed in this invention. The struts1501have a large opening angle relative to the longitudinal vessel axis which promotes improved clot grip as the greater the angle of the strut to the direction of movement, the greater the ability of the strut to grip the clot rather than slide past it. Similarly the inner diameter of the crown1502is increased to also improve clot grip by maximizing the length of the crown that is near perpendicular to the direction of travel within the clot. The length of the strut connector1503increases the total cell area1504to provide rings of cells in the device with low radial force and low strut surface area to promote clot embedding and protrusion into these cells. When the device is resheathed with the microcatheter the protruding clot is pushed against the struts1501and into the crown space1505trapping it and pinching it in position. Another embodiment of the device cut pattern is shown inFIG.39. In this configuration the strut shape and bend angle1553adjacent to the crown1551is sized so that on resheathing with the microcatheter1555, the adjoining struts close together1554creating another pinch point to help grip the clot that is protruding into the cell area (not shown). As described inFIG.38, the larger the crown inner diameter in the cut pattern the longer the portion of the crown which is near perpendicular to the longitudinal axis of the vessel (and the direction of clot movement), the better the clot dislodgement capability.FIG.40shows a crown configuration which allows the crown diameter to be maximized while enabling the device to be wrapped into the loaded configuration for delivery through the microcatheter to the target vessel location. To minimize the wrapped diameter, the crowns1603,1604and1605are offset along the longitudinal axis so that in the collapsed configuration the crowns fit into the space either side of the short connector, for example1606. To generate this crown offset the adjoining struts1601and1602have different lengths. FIG.41shows another embodiment of the device where the cut pattern is configured so that the crown1653maintains its full diameter during resheathing by the microcatheter1651so that the maximum quantity of clot can be pushed from the cell1655into the crown space1652by the microcatheter tip1654creating a pinch.FIG.42shows an embodiment of the cut pattern where the proximal facing crowns1703are similar to those described inFIG.41where the crown space1701is maximized for improved clot pinching. In this configuration the distal facing crown diameter1704is reduced as the crown is not required for clot pinching and the reduced diameter may facilitate a lower resheathing force and increased radial force in the adjacent struts1702. FIG.43shows an embodiment of the device where the proximal facing crowns1721,1723have a larger diameter than the distal facing crowns1725for improved clot pinching as detailed inFIG.42. The alternating rings of cells along the longitudinal axis of this device have different areas with cell1726having a larger area than1720. Hence more clot is likely to embed and protrude into cell1726. The clot protruding into the cell1726will get pushed towards crown1723by the microcatheter when resheathing. To ensure this resheathing is smooth with good tactile feedback to the physician, the length of strut1724is increased to reduce the feeling of ‘bumping’ as the catheter goes from low radial force segments to high radial force segments. In addition the length of strut1722is shortened to increase radial force in the ring of struts which is supporting crown1723. This keeps the crown1723expanded for longer during resheathing by the microcatheter increasing the pinch effectiveness. FIGS.44a-cshow a strut/crown configuration which promotes clot pinching along the length of the strut.FIG.44ashows the struts1757and1758in the freely expanded configuration. Strut1758is produced so that it contains a series of bends1751,1752and1759approaching the crown1753. Similarly strut1757contains a series of matching bends1754,1755and1756. As the device is resheathed in the microcatheter, the diameter of the device reduces and the struts move closer together.FIG.44billustrates that as the diameter reduces, the bends in the struts interlock creating pinch points such as between points1808and1805, and between1804and1807. This helps to grip the protruding clot which is embedded between the two struts as shown inFIG.44c. InFIG.44cpart of the clot1852protrudes into the cell between the struts. As the device is resheathed by the microcatheter (not shown), struts1850and1851move closer together generating a pinch on the protruding clot1853. This clot pinching improves device efficacy with enhanced clot dislodgement capability and safe clot retrieval into the access catheter. Another embodiment of the invention is shown inFIG.45. This figure illustrates the profile and outer shape of the device1900but does not show the strut pattern for clarity. In this embodiment the proximal section of the device1905is formed into a spiral configuration as described inFIGS.29to33. This proximal section1905is also configured to pinch the clot when partially resheathed by the microcatheter. As before the struts have opening angles and crowns to facilitate clot pinching and the cell size promotes clot protrusion to further improve pinching between the microcatheter and the device during resheathing. The body section1901is configured to expand in a cylindrical or uniform shape to provide clot grip and retention during retraction of the clot past vessel bends and branches. The body section is also particularly suited to the grip and retention of softer clot with red blood cell content in the range of 30-100% but particularly clots with red blood cell content greater than 50%. In this configuration the device is effective at dislodging and retaining fibrin rich and red blood cell rich clots by gripping the fibrin rich clot by partial resheathing with the microcatheter over the proximal section1905, while gripping and retaining the softer or heterogeneous clots by the body section1901. The device1900shown in this figure is connected to a proximal shaft (not shown) at the proximal joint1904and has a fragment protection zone1902. The proximal spiral section1905is connected to the body section1901at1906. This connection may be centred and be concentric with the body section or may be eccentric, for example aligning with the outer surface of the body section. The flared section1903between the proximal tubular section and the body section can include large cell openings to facilitate clot migrating into the body section for improved retention and fragment protection. FIG.46shows an end view of the device1900illustrated inFIG.45when viewed from direction ‘A’ as shown. In this figure the spiral outer surface1951has a larger diameter (O′S′) than the body section diameter1952(O′B′). In other embodiments (not shown) the spiral outer diameter may be equal or smaller than the body section diameter. The spiral outer diameter is typically between 2.0 and 8.0 mm diameter and in the preferred embodiment is between 4.0 and 6.0 mm. The body section diameter can vary from 1.0 to 8.0 mm and in the preferred embodiment is between 3.0 and 6.0 mm. The body section is shown in a cylindrical configuration in this embodiment however this section may also be formed into a spiral or curved shape with a different pitch, tubing diameter and spiral diameter to the proximal section. The embodiment2000shown inFIG.47has a similar shape to the device illustrated inFIGS.45and46with additional strut and construction details. This embodiment is shown connected to a proximal shaft2007by the proximal struts2008. The proximal section2001is formed in a spiral configuration and the body section2002is formed in a cylindrical shape. The distal end of the device forms a cone shape to provide fragment protection capabilities. A radiopaque coil or marker2003is added to the distal tip for visibility under fluoroscopy. An additional radiopaque marker2005is added to the device at or near the transition from the spiral section to the body section. This marker2005highlights the end of the spiral section2001and can be used to distinguish the optimum point to stop resheathing with the microcatheter. This radiopaque marker may also be used to align the device with the proximal face of the clot for red blood cell rich clots. Similarly a radiopaque coil (not shown) on the distal end of the shaft2007can be used to align the spiral pinch section2001with the proximal face of fibrin rich clots. The proximal spiral section is typically 5 to 30 mm in length and in the preferred embodiment is between 8 and 15 mm in length. Additional radiopaque markers can be added along the spiral section to provide increased visual feedback and clarity for the resheathing process with the microcatheter.FIG.47also illustrates the cell openings2006at the diameter transition from the spiral tube to the body section which are designed to facilitate clot entering partially or fully inside the body section2002. FIG.48shows another embodiment2050of the device where only the shaft2052and the outer shape of the spiral and body sections2051are shown. In this embodiment the radiopaque marker2055which distinguishes the end of the spiral section2056is mounted on an extension2054to the proximal shaft2052. This shaft extension2054continues distal of the proximal joint2053which connects the spiral section to the shaft2052. FIG.49ashows a partial plan view of the embodiment2100detailed previously inFIGS.6a-dand illustrates the large cell area2102which promotes clot protrusion into the device so that it can be pinned against struts2103and2104when the device is resheathed with a microcatheter. InFIG.49bthe device2122is shown deployed in a clot2121which is located in an arterial vessel2120. The device2122is connected to a proximal shaft2123. On deployment of the device, the ring of struts and cells2125embed in the clot, while the clot section2124positioned over the large open cell section2126protrudes into the device. The large open cell section promotes clot protrusion into the device, minimising clot compression and subsequent increase in friction with the vessel wall2120. FIG.49cillustrates how the protruding section2142of the clot2141is pushed against the ring of struts and crowns2144by the catheter tip2145to generate the grip on the clot to facilitate dislodgement and retrieval from the vasculature. The invention disclosed here is more effective and reliable at generating a clot grip and pinch than existing stent retriever technology when resheathed with a catheter.FIG.50a-cillustrates what happens when an existing stent retriever device2200(prior art) is resheathed with a microcatheter.FIG.50ashows stent retriever2203deployed in a clot2201. Strut embedding occurs in the clot2201and some clot protrudes into the open cells2203. A typical stent retriever has an outer diameter in the range of 4 to 6 mm and as the device2224is resheathed as shown inFIG.50b, it contracts and pulls away from the clot2220. Therefore as the microcatheter2221is advanced, the struts2223which were embedded in the clot2220pull away from the clot surface and the clot protrusion in the cell is lost allowing the microcatheter to advance fully, resheathing the device underneath the clot.FIG.50cshows how the strut length2242and crown opening angle2244dictate the resheathing angle2241of the device, as it is resheathed by catheter2240. The greater this angle2241from the vertical, the more likely the device struts will pull away from the surface of the clot during resheathing. The length2245is the distance from the catheter tip that the device diameter starts to contract as the catheter is forwarded. This length increases as the resheathing angle increases (from vertical), reducing the contact of the device struts with the clot. In comparison toFIGS.50a-cof existing stent retriever technology,FIGS.51a-cshow an embodiment of the invention deployed in a clot.FIG.51aillustrates a device2300, similar to that described elsewhere in this patent, deployed in a clot2301. The rings of struts2303embed into the clot and the clot2302protrudes into the large open cells2305. As the device is resheathed with a catheter as shown inFIG.51b, the strut length, crown configuration and radial force profile along the device length maintain strut embedding in the clot and clot protrusion in the cells as the catheter tip approaches. Therefore the clot2322is still protruding in the device cell during the resheathing process and is pushed against the adjacent strut2326and crown2325, pinching it in position. Crown2325is also supported by the ring of struts2324to ensure it stays expanded and embedded in the clot for longer during the resheathing process. This performance characteristic is reflected in the reduced resheathing angle (from vertical) shown inFIG.51cand the significantly reduced length2345showing that the device diameter does not contract except in the immediate vicinity of the catheter tip. This feature is further facilitated by the alternating higher and lower radial force profile along the device length as described previously inFIGS.3a-d. The preferred embodiment of this device has an outer diameter of 2 to 3 mm which facilitates shorter strut lengths which allow higher crown expansion angles during the resheathing process than standard stent retrievers which typically expand to 4 to 6 mm. This is illustrated inFIGS.52aandbwhereFIG.52ashows the expanded struts2402of a 3 cell conventional stent retriever with a 4 mm outer diameter, which has been unrolled into a 2D configuration. This same device is shown inFIG.52bwhen contracted to a 2 mm diameter, showing the strut length2423and how the crown opening angle has reduced from2401inFIGS.52ato2422inFIG.52b. In comparison a strut configuration of the invention is shown inFIG.53illustrating the large expanded angle2442of the struts plus the large crown ID 2443 to facilitate pinching. This device is still effective at 2 mm diameter as the clot engagement and retention is provided by pinching the clot between the microcatheter tip and the crown and struts of the device rather than pinning the clot partially or fully against the vessel wall by the device to maintain strut embedding and clot engagement. The strut configuration shown inFIGS.54aand54bprovide additional benefits to help generate a pinch and dislodge occlusive clots. The strut pattern of the device2504inFIG.54ais shown unrolled into a 2D configuration. When the device2504is resheathed with a microcatheter, the outer diameter reduces causing the neck point2505to move towards the opposite neck point2501. This can help grip the clot protruding in the cell2503and maintain the clot in this position as the microcatheter advances and pushes the clot against crown2502, pinning it and generating a pinch grip.FIG.54bfurther illustrates how the neck points2553close together providing additional grip on the clot (not shown) that is positioned between the microcatheter tip2555and the crown2551, to facilitate pinching and also enhance the grip and retention of the clot as it is retracted past bends and branches to the access catheter. It will be apparent from the foregoing description that while particular embodiments of the present invention have been illustrated and described, various modifications can be made without departing from the spirit and scope of the invention. For example, while the embodiments described herein refer to particular features, the invention includes embodiments having different combinations of features. The invention also includes embodiments that do not include all of the specific features described. The invention is not limited to the embodiments hereinbefore described which may be varied in construction and detail.

11857211

DETAILED DESCRIPTION Reference will now be made in detail to the subject matter disclosed, which is illustrated in the accompanying drawings. Referring generally toFIGS.1A through5C, an obstruction removal system is described, in particular, an obstruction removal system configured to selectively deploy a removal tool with an expandable member in a vasculature to reduce the risks associated with removal of an obstruction. The expandable member may be used to prevent the obstruction from dislodging from the removal tool and passing to a potentially more dangerous area (e.g. causing a total blockage, blocking a portion of a vital vasculature, etc.). In this regard, a physician may determine whether an obstruction is prone to risk and selectively deploy the removal tool with the expandable member. FIGS.1A through1Fillustrate one or more embodiments of an obstruction removal system100. As shown inFIG.1A, the obstruction removal system100includes a guide catheter104(e.g., any suitable guide catheter, aspiration catheter, or any other suitable tube) configured to be inserted through a vasculature102to a position proximate to an obstruction101. Referring now toFIG.1B, the obstruction removal system100further includes an obstruction removal device comprising a removal tool110and an expandable member112configured to be inserted through the guide catheter104. For example, the removal tool110and the expandable member112may be coupled or formed on/near a distal end of a delivery tool108that is configured to be inserted through the guide catheter104. In embodiments, the delivery tool108may be a guide wire or tube. In this regard, the removal tool110may be fixed to the distal end of the guide wire or tube, and the expandable member112may be fixed or slidably coupled to the guide wire or tube at a position near the removal tool110. In embodiments, the obstruction removal device (i.e., the removal tool110and the expandable member112on the delivery tool108) may be at least partially housed within an intermediate catheter106(e.g., any suitable intermediate catheter, microcatheter, or any other suitable tube) during insertion. The intermediate catheter106may be used to contain and keep the removal tool110and the expandable member112from expanding within the guide catheter104. This may provide one or more advantages, such as, but not limited to, reducing friction between the removal tool110/expandable member112and the guide catheter104, permitting the removal tool110and the expandable member112to be inserted through the distal opening of the guide catheter104, and preventing the removal tool110/expandable member112from prematurely engaging the obstruction101. FIG.1Billustrates the obstruction removal device deployed within the vasculature102in proximity to an obstruction101. The delivery tool108(e.g., a guide wire and/or tube) is configured to be inserted within the guide catheter104and disposed proximate to the obstruction101in the vasculature102. For example, the delivery tool108, carrying the end-mounted the removal tool110and the expandable member112, may be fed through the guide catheter104using the intermediate catheter106to contain/sheathe the removal tool110and the expandable member112during their insertion. Referring now toFIG.1C, the intermediate catheter106may be configured to unsheathe the removal tool110and the expandable member112so that the removal tool110can engage the obstruction101in the vasculature102. For example, after reaching a desired position within the vasculature102, the intermediate catheter106may be pulled back (and/or the delivery tool108may be pushed forward relative to the intermediate catheter106) to unsheathe the removal tool110and the expandable member112so that the removal tool110can engage the obstruction101. The removal tool110is configured to at least partially separate the obstruction101from the inner surface of the vasculature102(e.g., from the vessel wall). In embodiments, the removal tool110comprises a conical or umbrella-shaped section (e.g., a conical and/or umbrella shaped net-like structure or mesh) configured to at least partially surround the obstruction101. In other embodiments, the removal tool110comprises a differently shaped net-like structure or mesh configured to at least partially surround the obstruction101(e.g., a semi-circular or cylindrical structure, or the like). In embodiments where the delivery tool108comprises a guide wire disposed within a tube, the distal end of the removal tool110may be attached to the guide wire and another (mid) portion of the removal tool may be attached to the tube so that moving the guide wire independent of (e.g., relative to) the tube causes the removal tool110to expand or collapse, much like an umbrella. Additionally, or alternatively, the removal tool110may be formed from a shape memory and/or super elastic alloy (e.g., Nitinol) so that the removal tool110automatically expands when it is unsheathed. For example, the removal tool110may be guided past the obstruction101, unsheathed, and then pulled back to scrape/scoop the obstruction101off the inner surface of the vasculature102. The expandable member112includes a distal end114that is fixedly or slidably coupled to the delivery tool110and a proximal end116that is slidably coupled to the delivery tool110. The expandable member112may be positioned so that, during its deployment, the distal end114is located in between the removal tool110and the proximal end116. As shown inFIG.1D, when the delivery tool108is withdrawn (e.g., pulled back into the guide catheter104and/or intermediate catheter106), the proximal end116of the expandable member112may be configured to slide toward the distal end114of the expandable member112, thereby causing the expandable member112to surround at least a portion of the obstruction101and the removal tool110so that the obstruction101is captured between the expandable member112and the removal tool110. In embodiments, when the proximal end116of the expandable member112slides toward the distal end114of the expandable member112as a result of the delivery tool108being removed from the vasculature102to remove the removal tool110and the obstruction101from the vasculature102, a middle portion118of the expandable member112is configured to fold over the distal end114of the expandable member112and at least a portion of the removal tool110, so that the obstruction101is captured between the expandable member112and the removal tool110. For example, when the delivery tool108is pulled back through the guide catheter104and/or intermediate catheter106, the resulting friction between the middle portion118of the expandable member112and the inner surface of the vasculature102(e.g., as shownFIG.1D-1), the guide catheter104, or the intermediate catheter106may cause the middle portion of the expandable member112to fold over the removal tool110so that the obstruction101is captured between the expandable member112and the removal tool110. Additionally, or alternatively, when the delivery tool108is pulled back through the guide catheter104and/or intermediate catheter106, the resistance from fluid in the vasculature102may cause the middle portion of the expandable member112to fold over the removal tool110so that the obstruction101is captured between the expandable member112and the removal tool110. Furthermore, as shown inFIG.1D-2, in some embodiments, the intermediate catheter106(or guide catheter104) may be used to urge the expandable member112to invert and/or fold over itself. FIG.1Eillustrates the obstruction101captured between the expandable member112and the removal tool110, as the delivery tool108is being withdrawn from the vasculature102to remove the removal tool110and the obstruction101from the vasculature102. For example, the delivery tool108may be pulled back into the guide catheter104and/or intermediate catheter106to remove the obstruction101that is captured between the expandable member112and the removal tool110from the vasculature102. As shown inFIG.1F, the intermediate catheter106with the delivery tool108and the obstruction101that is captured between the expandable member112and the removal tool110may be pulled back through the guide catheter104to remove the obstruction101from the vasculature102. The delivery tool108with the obstruction removal device (including removal tool110and expandable member112) and the obstruction101may be withdrawn through the intermediate catheter106, as depicted inFIG.1F. Alternatively, the delivery tool108with the obstruction101that is captured between the expandable member112and the removal tool110may be pulled directly through the guide catheter104(without use of an intermediate catheter106). FIGS.2A through2Fillustrate another embodiment of the obstruction removal system100, wherein the expandable member112has a distal end114coupled to the delivery tool108and a proximal end116that is configured to move freely. For example, the expandable member112may comprise a conical/umbrella-shaped net or mesh structure with one end fixedly or slidably coupled to the delivery tool108and one free/open end. As shown inFIGS.2B and2C, when the obstruction removal device (i.e., the removal tool110and the expandable member112on the delivery tool108) is being guided through the vasculature102to the obstruction101, the expandable member112may be oriented so that the proximal end116of the expandable member112is facing away from the removal tool110. Then, as shown inFIG.2D, when the delivery tool108is withdrawn (e.g., pulled back into the guide catheter104and/or intermediate catheter106), the proximal end116of the expandable member112may be configured to invert toward the distal end114of the expandable member112, thereby causing the expandable member112to surround at least a portion of the obstruction101and the removal tool110so that the obstruction101is captured between the expandable member112and the removal tool110. In embodiments, the proximal end116of the expandable member112is configured to invert and drape over the distal end114of the expandable member112and at least a portion of the removal tool110as the delivery tool108is withdrawn from the vasculature102to remove the removal tool110and the obstruction101from the vasculature102. For example, when the delivery tool108is pulled back through the guide catheter104and/or intermediate catheter106, the resulting friction between the proximal (i.e., free) end116of the expandable member112and the inner surface of the vasculature102, the guide catheter104, or the intermediate catheter106may cause the expandable member112to invert and drape over the removal tool110so that the obstruction101is captured between the expandable member112and the removal tool110. Additionally, or alternatively, when the delivery tool108is pulled back through the guide catheter104and/or intermediate catheter106, the resistance from fluid in the vasculature102may cause the expandable member112to invert and drape over the removal tool110so that the obstruction101is captured between the expandable member112and the removal tool110. FIG.2Eillustrates the obstruction101captured between the expandable member112and the removal tool110, as the delivery tool108is being withdrawn from the vasculature102to remove the removal tool110and the obstruction101from the vasculature102. For example, the delivery tool108may be pulled back into the guide catheter104and/or intermediate catheter106to remove the obstruction101that is captured between the expandable member112and the removal tool110from the vasculature102. As shown inFIG.2F, the intermediate catheter106with the delivery tool108and the obstruction101that is captured between the expandable member112and the removal tool110may be pulled back through the guide catheter104to remove the obstruction101from the vasculature102. The delivery tool108with the obstruction removal device (including removal tool110and expandable member112) and the obstruction101may be withdrawn through the intermediate catheter106, as depicted inFIG.2F. Alternatively, the delivery tool108with the obstruction101that is captured between the expandable member112and the removal tool110may be pulled directly through the guide catheter104(without use of an intermediate catheter106). Referring now toFIGS.3A through5C, various embodiments of the removal tool110are shown and described. Embodiments of the removal tool110illustrated inFIGS.3A through5Cmay be employed with any embodiments of the obstruction removal system100illustrated inFIGS.1A through2For otherwise described herein. In embodiments, such as those illustrated inFIGS.3A and3B, the obstruction removal device may include a passive removal tool110. In this regard, the removal tool110may be configured to expand upon deployment (e.g., unsheathing) from the intermediate catheter106. The removal tool110may include a distal end109(e.g., tip coil) that is fixed to a distal end of the delivery tool108(e.g., delivery tube or wire) and a proximal end111that is fixed or slidably coupled to another portion of the delivery tool108such that an obstruction landing area120on the delivery tool108is defined between the proximal end111of the removal tool110and the distal end114of the expandable member112. In some embodiments, the ends of the removal tool110and/or expandable member112comprise marker bands that are coupled to the delivery tool108. FIGS.4A through4Cillustrate embodiments of the obstruction removal device including an active removal tool110. In this regard, the removal tool110may be selectively expanded or collapsed. For example, the removal tool110may be expanded or collapsed by actuating two portions of a delivery tool108(e.g., a delivery wire108A and a delivery tube108B) relative to one another. The removal tool110may include a distal end109(e.g., tip coil) that is fixed to a distal end of the delivery wire108A and a proximal end111that is fixed to a distal end of the delivery tube108B, either directly or via an obstruction landing area120between the proximal end111of the removal tool110and the distal end114of the expandable member112(as shown). In embodiments, the expandable member112may be coupled to the delivery tube108B such that the obstruction landing area120is defined between the proximal end111of the removal tool110and the distal end114of the expandable member112. The obstruction landing area120may comprise a wire mesh portion that connects the removal tool110and the expandable member112together. In some embodiments, the expandable member112and the removal tool110may be portions of a continuous wire mesh structure. The ends of the removal tool110and/or expandable member112may comprise marker bands that are coupled to respective portions of the delivery wire108A and tube108B. As shown inFIGS.4A and4B, respectively, the removal tool110may be collapsed by pushing the delivery wire108A through the delivery tube108B (or pulling the delivery tube108B away from the distal end of the delivery wire108A) and may expanded by pulling the delivery wire108A through the delivery tube108B (or pushing the delivery tube108B toward the distal end of the delivery wire108A). FIGS.5A through5Cillustrate embodiments of the obstruction removal device including an active removal tool110and an active expandable member112. In this regard, the removal tool110and the expandable member112may be selectively expanded or collapsed. For example, the removal tool110may be expanded or collapsed by actuating two portions of a delivery tool108(e.g., a delivery wire108A and a delivery tube108B) relative to one another. The removal tool110may include a distal end109(e.g., tip coil) that is fixed to a distal end of the delivery wire108A and a proximal end111that is connected to the distal end114of the expandable member112via an obstruction landing area120between the proximal end111of the removal tool110and the distal end114of the expandable member112. The obstruction landing area120may comprise a wire mesh portion that connects the removal tool110and the expandable member112together. In some embodiments, the expandable member112and the removal tool110may be portions of a continuous wire mesh structure. The ends of the removal tool110and/or expandable member112may comprise marker bands that are coupled to respective portions of the delivery wire108A and tube108B. As shown inFIGS.5A through5C, the proximal end116of the expandable member112may be coupled to a distal end of the delivery tube108B so that pulling the delivery tube108B back relative to the delivery wire108A (or extending the delivery wire108A forward relative to the delivery tube108B) causes the removal tool110and the expandable member112to collapse; and conversely, pulling the delivery wire108A back relative to the delivery tube108B (or pushing the delivery tube108B forward relative to the delivery wire108A) causes the removal tool110and the expandable member112to expand. As shown inFIGS.3B,4C, and5C, in some embodiments, the removal tool110may include a support frame122(e.g., one or more rigid or semi-rigid structures) that provide structural reinforcement for the removal tool110when the removal tool110is in a deployed (i.e., expanded) configuration. The support frame122may be configured to collapse (e.g., fold toward the delivery tool108) when the removal tool110is in a collapsed configuration. Additionally, or alternatively, the removal tool110may include non-uniform wire mesh. For example, the removal tool110structure may comprise thicker, stronger, and/or denser wire mesh toward the distal end109of the removal tool110to provide a stronger conical/funnel shaped structure when the removal tool110is deployed/expanded and thinner, weaker, and/or less dense wire mesh toward the proximal end111of the removal tool110to provide flexibility for the removal tool110to expand/collapse more easily. In the embodiments illustrated inFIGS.1A through5C, or combinations thereof, the expandable member112may be configured to transition between contracted/collapsed and expanded states. The expandable member112may be configured to transition between the contracted and expanded states in any suitable way, including, but not limited to, unsheathing the expandable member112to allow expansion and sheathing/re-sheathing the expandable member112to induce contraction. The expanded state may allow the expandable member112to surround at least a portion of the removal tool110and/or the obstruction101. The contracted state may be suitable for insertion and removal of the obstruction removal device (including expandable member112and removal tool110) through the guide catheter104and/or intermediate catheter106. For example, when the expandable member112is in the collapsed/contracted state, after surrounding at least a portion of the removal tool110and/or the obstruction101, the expandable member112and the removal tool110may be withdrawn through the guide catheter104and/or the intermediate catheter106to remove the obstruction101from the vasculature102. Benefits of surrounding at least a portion of the removal tool110and/or the obstruction101with the expandable member112may include, but are not limited to, smaller cross-sectional area, reduced friction on a vessel wall, reduced likelihood of catching on an opening of the guide catheter104and/or intermediate catheter106, and reduced likelihood of obstruction dislodgement. Referring generally to embodiments of the obstruction removal system100disclosed herein, the expandable member112may be configured to transition between a first configuration and a second configuration, or between a contracted state and an expanded state, in any number of ways, including, but not limited to, unsheathing (e.g., withdrawal of the intermediate catheter106or extension through the guide catheter104), disengagement of locking members (e.g., wires, hooks, etc.) attached to the expandable member112, use of shape memory alloys (e.g., Nitinol), or the like. It is envisioned that when the expandable member is in an expanded state, the expandable member may take up a substantial portion of the cross-section of the vasculature102. In embodiments, the expandable member112, removal tool110, and the obstruction101are withdrawn into the guide catheter104and removed from the vasculature102. In some embodiments, the expandable member112, removal tool110, and the obstruction101may be further withdrawn into the intermediate catheter106. The expandable member112may surround at least a portion of the obstruction101to prevent dislodging and may also assist in compressing the obstruction101into the guide catheter104and/or the intermediate catheter106(e.g., by tension, cinching, crimping, etc.). Surrounding at least a portion of the removal tool110and/or obstruction101with the expandable member112may serve several functions including, but not limited to, reducing a likelihood that the removal tool110snags (e.g. on an inner surface/vessel wall of the vasculature102or an opening of the guide catheter104), reducing a profile of the obstruction101for removal through the guide catheter104and/or intermediate catheter106, and/or securing the obstruction101to prevent dislodgement from the removal tool110. In embodiments, the removal tool110and/or expandable member112may comprise a wire mesh. Such a wire mesh may include wires made of a flexible material (e.g. nitinol, cobalt chromium, polymer mesh (e.g., PET or nylon), or the like), where the wires (e.g. 16 to 288 or more wires), have a certain diameter (e.g. from 0.0005 inches to 0.0050 inches), and have certain material properties (e.g. strength, coefficient of friction with blood, resistance to plastic deformation, etc.) suitable for engaging the obstruction101and/or removal tool110. The wire mesh can be can be single ply or multiple plies. Furthermore, the wire mesh may include various sets of wires (e.g. support wires with larger diameters, wires to engage a vessel wall, wires to engage a portion of the obstruction or obstruction removal device, radiopaque or radiodense wires, etc.). Any number of the presently disclosed elements may be suitable for imaging by a non-invasive imaging technology (e.g. X-ray, CT scans, etc.). For instance, the guide catheter104, intermediate catheter106, delivery tool108, removal tool110, expandable member112, and/or any additional components may comprise radiodense or radiopaque material (e.g. titanium, tungsten, barium sulfate, zirconium oxide, Drawn Filled Tube (DFT), or the like) suitable for insertion in a human body. In some embodiments, the removal tool110and the expandable member112are both portions of a common wire mesh structure formed from a radiodense or radiopaque material (e.g. DFT). It is to be understood that any number of components of the obstruction removal system100may be attached by any suitable means including, but not limited to, welding, adhesive, mechanical fastening, interference fittings, etc. For example, the delivery tool108may be attached to the removal tool110and/or expandable member112by such means. Alternatively, or additionally, two or more of the components may be portions of a common structure (e.g., a common mold or print). It is envisioned that there may be multiple orders in which one or more devices of the obstruction removal system100are deployed. Factors for determining an order may include, but are not limited to, vasculature properties (e.g. vasculature size, vasculature geometries, branches of the vasculature, vasculature wall strength, etc.), blood pressure, blood flow direction, duration of operation (i.e. does patient require a reduced operating time for safety concerns), size of obstruction, or the configuration of the obstruction removal device. Referring generally toFIGS.1A through5C, a method of removing an obstruction from a vasculature102may include, but is not limited to, the steps of: deploying the guide catheter104through the patient's vasculature102to a position near the obstruction101; extending the delivery tool108with the end-mounted removal tool110through the guide catheter104so that the distal end of the delivery tool108is disposed proximate to the obstruction101in the vasculature102(with/without the use of the intermediate catheter106); removing at least a portion of the obstruction101in the vasculature102by at least partially separating the obstruction101from an inner surface of the vasculature102with the removal tool110; and surrounding at least a portion of the obstruction101and the removal tool110with the expandable member112, wherein the proximal end116of the expandable member112is configured to invert or slide toward the distal end114of the expandable member112, so that the obstruction101is captured between the expandable member112and the removal tool110, when the delivery tool108is withdrawn from the vasculature102to remove the removal tool110and the obstruction101from the vasculature102. It is to be understood that implementations of the methods disclosed herein may include one or more of the steps described herein. Further, such steps may be carried out in any desired order and, in some implementations, two or more of the steps may be carried out simultaneously with one another. Two or more of the steps disclosed herein may be combined in a single step, and in some implementations, one or more of the steps may be carried out as two or more sub-steps. Further, other steps or sub-steps may be carried in addition to, or as substitutes to one or more of the steps disclosed herein. It is also to be understood that usage of terminology in the present disclosure is not intended to be limiting. For example, as used herein, an “obstruction” may refer to any vascular obstruction, including but not limited to, a blood clot, plaque (e.g. fat, cholesterol, etc.), internal structure/growth, foreign object, or the like. Although the technology has been described with reference to the embodiments illustrated in the attached drawing figures, equivalents may be employed and substitutions made herein without departing from the scope of the technology as recited in the claims. Components illustrated and described herein are merely examples of a device and components that may be used to implement the embodiments of the present invention and may be replaced with other devices and components without departing from the scope of the invention. Furthermore, any dimensions, degrees, and/or numerical ranges provided herein are to be understood as non-limiting examples unless otherwise specified in the claims.

11857212

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS Certain embodiments of the present systems and apparatuses are configured to generate high-frequency shock waves while having an improved electrode lifetime. In some embodiments, the generated EH shock waves can be used in medical and/or aesthetic therapeutic applications (e.g., when directed at and/or delivered to target tissue of a patient). Examples of medical and/or aesthetic therapeutic applications in which the present systems can be used are disclosed in: (1) U.S. patent application Ser. No. 13/574,228, published as US 2013/0046207; (2) U.S. patent application Ser. No. 13/547,995, published as, published as US 2013/0018287; and (3) U.S. patent application Ser. No. 13/798,710, published as US 2014/0257144, each of which are incorporated here in their entireties. In one embodiment, the apparatus for electrohydraulic generation of shockwaves comprises: a housing defining a chamber and a shockwave outlet; a liquid disposed in the chamber; a plurality of electrodes (e.g., in the spark head or module) configured to be disposed in the chamber to define one or more spark gaps; and a pulse generation system configured to apply voltage pulses to the electrodes at a rate of between 10 Hz and 5 MHz. The rate of voltage pulses may be at rates of 25 Hz, 50 Hz, 75 Hz, 100 Hz, 150 Hz, 200 Hz, 250 Hz, 300 Hz, 400 Hz, 500 Hz, 600 Hz, 700 Hz, 800 Hz, 900 Hz, 1 KHz, 5 KHz, 10 KHz, 25 KHz, 50 KHz, 100 KHz, 200 KHz, 300 KHz, 400 KHz, 500 KHz, 600 KHz, 700 KHz, 800 KHz, 900 KHz, 1 MHz, 2 MHz, 3 MHz, and 4 MHz. A. Prior Art Systems Referring now to the drawings,FIG.1depicts a typical pulse discharge from prior art electrohydraulic systems which produce a broad frequency spectrum acoustic wave (typically in the range of 16 Hz to 30 MHz) consisting of a large compressive pulse wave100, followed by a small tensile wave102. The compressive pulse wave100consists of two parts: a fast rise acoustic front104(also referred to as a shock wave front) followed by a long compressive acoustic tail106. The fast acoustic front104occurs on a time scale of nanoseconds whereas the long compressive acoustic tail106occurs on a time scale of microseconds. Such prior art electrohydraulic systems create a pulse discharge event between two electrodes that takes place in four stages: (1) inter-electrode saline heating and initial vaporization; (2) vapor ionization; (3) inter-electrode arc formation; and (4) intense arc. FIG.2Adepicts Stage1of the prior art pulse discharge event: inter-electrode saline heating and initial vaporization. During this stage of the pulse, a chamber200is filled with saline202. Next, a pulse-generation system applies voltage directly to the electrodes204,206to produce an inter-electrode conductive path208. Specifically, current210is conducted through the bulk amount of saline202from one electrode204to another206. This results in the saline202being heated resulting in portions of the saline202being vaporized at initial bubble nucleation sites located on the surface tips of the electrodes204,206. Because the electrical conductivity of saline increases with temperature, during this stage the electrode current rises as the temperature of the saline increases. At this stage there is no electrode damage during the saline heating and initial vaporization. The current is approximately evenly distributed across the surface tips of the electrodes204,206and the temperature of the saline is low (up to approximately 100° C.) while overall impedance is high (approximately 50Ω for 1% saline). FIG.2Bdepicts Stage2of the prior art pulse discharge event: inter-electrode vapor ionization, which overlaps with Stage1as depicted inFIG.2A. During this stage of the pulse, current210is still being primarily conducted through the bulk amount of saline202from one electrode204to another206. Saline202continues to vaporize and expand from the initial bubble nucleation sites. Once the saline202vaporizes and its density is low enough, the increased free paths of the electrons allow them to acquire the energy sufficient for collisional ionization, and avalanche plasma discharges212are formed. As with Stage1, negligible damage to the electrode occurs during this stage. Ion bombardment can cause electrode material removal through sputtering, but rates are extremely low when compared to Stages3and4of the pulse discharge event. Overall impedance is high (approximately 50Ω for 1% saline). FIG.2Cdepicts Stage3of the prior art pulse discharge event: inter-electrode arc formation. During this stage of the pulse, multiple events happen almost simultaneously. The discharge through the saline vapor plasma layer causes cathode and anode spots to form on the surfaces of the electrodes. These tiny, intense jets of electrode material and electrons supply the conductive material necessary to form a full arc214. The jets emanating from the cathode and anode spots begin to connect and transition to the intense arc of Stage4. The net current across the electrodes204,206begins to spike as the initial arc214causes rapid and complete saline vaporization and arc spread. Overall impedance begins to drop from approximately 50Ω to 0.1Ω. FIG.2Ddepicts Stage4of the prior art pulse discharge event: inter-electrode intense arc., The intense arc mode216is very bright and appears to cover the anode and cathode, and fill the electrode gap218. Another and cathode spots are present and are continuously ejecting electrode material into the gap218which supplies the feeder material for the low-impedance arc. The intense arc mode216produced by prior art pulse-generation systems is characterized by sever erosion at the anode and cathode [1]. The arc voltage is low and the current is high, due to the low overall impedance (approximately 0.1Ω). Anode erosion is typically more severe than cathode erosion because the anode spots tend to be fewer and more intense, while the cathode spots are mot numerous and distributed [1]. The severe erosion of the electrodes204,206using prior art electrohydraulic systems limits the lifetime of the electrodes in those systems. Because many applications for electrohydraulic systems require large numbers or fast rates of pulses to be effective, the prior art approaches for generating these acoustic waves result in a lowering the limited lifetime of the electrodes204,206requiring either frequent electrode replacement or the use of an expensive, complicated electrode feeder system. Due to the limited electrode lifetime, these requirements have constrained electrohydraulic systems’ commercial usefulness. B. Improved Systems, Components, and Methods Certain embodiments of the present apparatuses and methods are configured to electrohydraulically generate shockwaves while providing improved electrode lifetime. Certain embodiments achieve improved electrode lifetime by utilizing a two stage pulse discharge approach to shockwave generation. In some embodiments, in the first stage, the pulse-generation system is configured to simultaneously: (1) apply voltage pulses to a plurality of electrodes in an electrode chamber such that a portion of a liquid contained within the chamber are vaporized to provide an inter-electrode conductive path; and (2) apply voltage pulses to charge a plurality of capacitors located adjacent to the plurality of electrodes. In such embodiments, in the second stage, the charged plurality of capacitors discharge to generate short inter-electrode arc through the established inter-electrode conductive path resulting in an acoustic shockwave. A shorter inter-electrode arc can minimize electrode erosion, and thereby lead to improved electrode lifetime. In electrohydraulic shockwave generation, high capacitance may be required to obtain the required peak pulse current with the desired waveform at the electrodes. In some of the present embodiments, large capacitors may be disposed close to the electrodes may be able to provide the high voltage pulse to the electrodes necessary to produce a short inter-electrode arc. However, the use of repeated large voltage and current phase discharges required to generate pulse shockwaves may cause damage to large capacitors, which may in turn lead to shockwave generator failure. The capacitor damage sustained in these prior art systems is theorized to be secondary to the piezoelectric effect of the capacitor plates leading to mechanical failure. This problem can limit the ability to produce a commercially viable rapid pulse shockwave generator that has an electrode lifetime of acceptable length. In some of the present embodiments, a plurality of small capacitors in parallel, arranged (e.g., in a low-inductance pattern) adjacent to the electrodes (e.g., in or on a hand-held housing in which the electrodes are disposed) can be used to produce a short inter-electrode arc. In this embodiment, a plurality of small capacitors in parallel, arranged in a low-inductance pattern adjacent to electrodes is able to provide the repeated and rapid large voltage and current pulse discharges required to generate rapid pulse shockwaves without damage to the capacitors. The piezoelectric effect on the materials for each small capacitor is limited when used within the plurality of small capacitors in parallel to generate rapid pulse shockwaves. As a result, in such embodiments, catastrophic capacitor mechanical failure is avoided, thereby improving the commercially viability of rapid pulse shockwave generators. In some of the present embodiments, a plurality of small capacitors in parallel may be placed in a plurality of stacked circuit boards so as to condense the area required for the capacitors. Additionally, placing the plurality of small capacitors on opposing sides of each stackable circuit board results not only in further reduction of surface area required for the capacitors, but also a reduction of the inductance caused by the use of the plurality of capacitors. FIG.3depicts a representative schematic of one embodiment of the disclosed electrohydraulic apparatus. In the embodiment shown, a pulse-generation system300is coupled to a head302by a cable304. The head302includes a plurality of electrodes306configured to define one or more spark gap308, and a plurality of capacitors310(e.g., with the electrodes and capacitors carried by a housing). As described below, the capacitors may, for example, be configured in a low-inductance pattern. In some such embodiments, the housing or body of the head302defines a housing within which the plurality of electrodes306is disposed (e.g., with a portion of each electrode extending into the chamber), and the plurality of capacitors310is carried by the housing (and/or may be disposed in a chamber312). The chamber312is configured to be filled with a liquid. In the embodiment shown, pulse-generation system300comprises a high voltage power supply314, a capacitor316, a primary switch318, a current probe320, a resistor322, an inductor324, and a voltage probe326. The high voltage power supply314may for example, be configured to supply 3000 volts (V). The pulse-generation system300is configured to apply voltage pulses to the plurality of electrodes306such that portion of the liquid disposed in the chamber312are vaporized to provide an inter-electrode conductive path. The pulse-generation system300is also configured to (e.g., simultaneously) apply voltage to the plurality of capacitors310within the chamber. Once charged, the plurality of capacitors310can discharge within the established inter-electrode conductive path to produce a short inter-electrode discharge arc. This discharge arc then results in the formation of a shockwave. In some embodiments, such as the one shown inFIGS.4A-4E, at least a portion of the plurality of capacitors310is coupled to a stackable circuit board400in a circular, low inductance pattern on both the top side408and the bottom side406of the stackable circuit board400.FIG.4Adepicts a bottom-up view of one embodiment of a stackable circuit board400having a plurality of capacitors310coupled to the bottom side406of the stackable circuit board400. In the embodiment shown, the stackable circuit board400is circular, having an outer edge402and an center aperture404. Surrounding the center aperture404, the stackable circuit board400has a plurality of additional apertures410and a plurality of pins412. In this embodiment, fourteen (14) pins412are coupled to the stackable circuit board400. Other embodiments may include 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 16, 17, 18, 19, 20 or more pins412surrounding the center aperture404. Pins412may, for example, be pogo pins or other connectors configured to establish, at least temporarily, an electrical connection between multiple circuit boards. Additionally, in the embodiment shown, the stackable circuit board400has a plurality of board-to-board connectors414running around its outer edge402. Connectors414may be arranged in single row as shown, or in two rows, and facilitate electrically coupling the stackable circuit board400with additional circuit boards. Connectors414may, for example, be configured to operate across a range of temperatures between −55° C. and 125° C. In the embodiment shown, capacitors310are coupled to stackable circuit boards400in a low inductance pattern. As shown, a low inductance pattern of capacitors may comprise a plurality of sets of capacitors, each set of capacitor comprising of a plurality of individual capacitors. In the low inductance pattern, the sets of capacitors are arranged such that each set is in parallel with each other set. According to one embodiment, as shown inFIGS.4A-4E, each set of capacitors is coupled to the stackable circuit board400such that one capacitor is coupled to the board400near the center aperture404and a plurality of additional capacitors are coupled to the board400such that they are in electrical communication with one another and extend radially away from the center aperture404towards the outer edge402. This portion of capacitors from the set is further configured such that they are in electrical communication with an additional portion of capacitors situated on the opposing side of the board (or another board, as shown inFIGS.6A-6D). This additional portion of capacitors is similarly configured such that they extend in series from the edge of the board402towards the center aperture404. According to the embodiment described, the overall configuration of capacitors is such that multiple sets of capacitors, each with a portion of the overall plurality of capacitors, extend from the center aperture404outward to the center edge402, continue to the opposite side of the board (or to another board), then extend from the edge of the board402back towards the center aperture404. Capacitors310, when so configured, may cause current to flow from the outer edge402of the stackable circuit board400towards the center aperture404or from the center aperture404of the stackable circuit board400towards the outer edge402. Such a configuration has been shown to result in reduced inductance across the entire capacitor array. For example, in some such embodiments, certain sets of the capacitors are configured to cause current to flow radially inward, and others of the sets of capacitors are configured to cause current to flow radially outward, resulting in “counter flows” of current that tend to cancel out or otherwise (e.g., via destructive interference), inductance during use. In some embodiments, portions of the capacitors are coupled to each of a plurality of stackable circuit boards, which may include 2, 3, 4, 5, or more individual boards. Portions of the plurality of capacitors may be coupled to either side—or both sides—of any of the stackable circuit boards. As shown, a stackable circuit board400may be circular in shape, and may have a carve out416extending inward from outer edge402toward the center aperture. In one embodiment, at least ten (10) planar capacitors in parallel, each having a capacitance of no greater than 100 nanoFarads (nF), are able to provide the repeated large voltage pulse discharges required to generate rapid pulse shockwaves without damage to the capacitors. In other embodiments, a minimum of 15, 20, 25, 30, 35, 40 45, or 50 planar capacitors may be used in parallel. Additionally, according to other embodiments, each capacitor may have a maximum capacitance of 95 nF, 90 nF, 85 nF, 80 nF, 75 nF, 70 nF, 65 nF, 60 nF, 55 nF, or 50 nF. In one embodiment, the capacitors each have a length of between 2 mm and 4 mm, and a width of between 1 mm and 3 mm. In embodiments in which the capacitors are arranged in sets of capacitors, plurality of capacitors may be arranged in between 2 and 20 sets of capacitors, with the sets connected in parallel (e.g., and the capacitors within each set connected in series). Alternatively, the plurality of capacitors may comprise 2, 5, 10, or 15 sets of capacitors. In some embodiments, each set of capacitors comprises fewer than 50 capacitors, but may alternatively comprise 5, 10, 15, 20, 25, 30, 35, 40, or 45 capacitors per set. In some embodiments, the plurality of capacitors comprises at least 100 capacitors. In some embodiments, the plurality of capacitors are arranged in a circuit having an overall inductance of between 2 nH and 200 nH. FIGS.5A-5Edepict perspective, cross-sectional, top, and side views of one embodiment of the present assemblies of stackable circuit boards including a capacitor array for use in shockwave pulse generating apparatuses.FIG.5Adepicts a perspective view of one embodiment of the present stackable circuit board assemblies;FIG.5Bdepicts another perspective view of the assembly;FIG.5Cdepicts a side cross-sectional view of the assembly;FIG.5Ddepicts a top view of the assembly; andFIG.5Edepicts a side view of the assembly. As shown, in this assembly, circuit board400is coupled to the second stackable circuit board500via connectors414such that capacitors310of circuit board400are electrically connected to second stackable circuit board500via the connectors (414). Circuit board400is also mechanically coupled to circuit board500via a central hub assembly502. According to this embodiment, Circuit board500provides the low-inductance return path from the central pin to the outermost row of capacitors310. FIGS.6A-6Ddepict perspective, cross-sectional, and exploded perspective views of another embodiment of the present capacitor array for use in the rapid therapeutic shockwave generation apparatuses and methods.FIG.6Adepicts a perspective view of the capacitor array;FIG.6Bdepicts a second perspective view of the capacitor array;FIG.6Cdepicts a cross-sectional view of the capacitor array; andFIG.6Ddepicts an exploded view of the capacitor array. In this embodiment, the plurality of capacitors310is placed on a first stacked circuit board400and a second stacked circuit board500, adjacent to a plurality of electrodes wherein the plurality of small capacitors310is placed on opposing sides of each stackable circuit board400,500in a low-inductance pattern. The circuit boards400,500are both electrically coupled to each other via board-to-board connectors414and mechanically coupled to each other via a central mechanical assembly502. In the embodiment shown, locating the plurality of capacitors310near the electrodes enables the arc to be discharged completely and quickly. Once the capacitors310within the chamber head (as illustrated by the embodiment depicted inFIG.3) are discharged, the inter-electrode arc ends, minimizing electrode erosion. In some embodiments, the improved lifetime of the electrodes is the result of the discharge of the plurality of capacitors310near the electrodes. Locating the plurality of capacitors310near the electrodes in a low inductance pattern provides the capacitor/electrode setup with an overall low inductance. As a result, the plurality of capacitors310within the chamber is able to be discharge completely and quickly. As shown, the central mechanical assembly502comprises a contact ring600, a ring adapter602, a spacer604, a replacement pin socket606, a center pin608, and a plurality of nuts610. The ring adapter602may have a plurality of teeth612that are configured to be inserted into apertures in the second stackable circuit board500such that the teeth612prevent the second stackable circuit board500from rotating independent from the ring adapter602. In the embodiment shown, the capacitors may be configured to cause current to flow from the center of the second stackable circuit board500towards its outer edge, through the board-to-board connectors414to the outer edge of the first stackable circuit board400and from there to the center of the first stackable circuit board400. Each stackable circuit board400,500may have a thickness of between 0.02 and 0.2 inches. Alternatively, the boards400,500may have thicknesses of between 0.03 and 0.125 inches, or between 0.04 and 0.1 inches. FIGS.7A-7Cdepict cross-sectional and side views of one embodiment of the disclosed capacitor array coupled shockwave generation chamber. According to the embodiment as shown inFIG.7A, the capacitor array700is coupled to plurality of electrodes comprising a proximal electrode702and a distal electrode704. In this embodiment, both the proximal electrode702and the distal electrode704are disposed in a chamber706, which is configured to be filled with liquid. In at least one embodiment, the chamber706is configured to be filled with saline. In yet another embodiment, the chamber706is filled with saline. The electrodes702,704are configured to have a short gap between them defining the discharge location708. The capacitor array700, along with the coupled electrodes702,704and chamber706, is configured to perform the two stage discharge approach to shockwave generation. In the first stage, the pulse-generation system is configured to simultaneously: (1) apply voltage pulses to a plurality of electrodes702,704in an electrode chamber706such that a portion of a liquid contained within the chamber706is vaporized to provide an inter-electrode conductive path in the discharge location708; and (2) apply voltage pulses to charge a plurality of capacitors located adjacent to the plurality of electrodes702,704in the capacitor array700. According to this embodiment, in the second stage, the charged plurality of capacitors discharge to generate short inter-electrode arc through the established inter-electrode conductive path in the discharge location708resulting in an acoustic shockwave. In some embodiments, using a two stage pulse discharge approach to generating shock waves results in a short inter-electrode arc times that minimizes electrode erosion, leading to improved electrode lifetime. Electrohydraulic systems that use a single stage pulse discharge approach (for example, where the pulse generation system applies voltage pulses directly to the electrodes to sequentially form the inter-electrode conductive path, and then generate the inter-electrode arc) suffer from long discharge arc times, and therefore significant electrode erosion. This significant electrode erosion leads to an electrohydraulic shockwave apparatus with short electrode lifetime, increasing the time and expenses necessary for maintenance. For example,FIGS.8A and8Bdepict photos comparing an electrode used by a prior art system compared to an electrode implementing the disclosed system.FIG.8Adepicts one embodiment of an electrode run with a prior art pulsed power supply using the single stage approach. In contrast,FIG.8Bdepicts an electrode run with one embodiment of the two-stage pulsed generation system disclosed herein. As can be seen by comparingFIGS.8A and8B, the electrode run using the prior art pulsed power supply (FIG.8A) showed significant erosion after less than 100 pulses. Large cratering indicates bulk electrode melt due to extended severe arc duration resulting from the single stage prior art system. Contrary to the electrode implementing the prior art system, the electrode run with the two—stage pulse generation system (FIG.8B) demonstrated only minimal erosion after 6,200 pulses. The electrode implementing the two-stage system had a wear rate reduction of 15× when compared to that of implementing the prior art system. For example, at equivalent pulse rates, the electrodes depicted inFIG.8Acoupled to a prior art pulse-generation system exhibited a wear rate of approximately 3,750 micro-inches per minute, whereas the electrodes depicted inFIG.8Bcoupled to one of the present, inventive two-stage pulse-generation approaches (including a pulse-generation system, and a housing-carried capacitor array), exhibited a wear rate of only 250 micro-inches per minute. Additionally, according to one embodiment, apparatuses and method for electrohydraulic generation of shockwaves using the two-stage approach disclosed herein generate acoustic waves that are “compressed” when compared to those waves generated by prior art systems.FIG.9depicts a graph illustrating the pressure over time of an acoustic wave generated by both the prior art system900as well as an acoustic wave generated by the proposed two-stage approach902. As can be seen fromFIG.9, in comparison to the prior art system, the acoustic wave generated by the two-stage approach has a faster rise acoustic front904than that of the prior art approach. More importantly, the long acoustic tail906is significantly compressed as a result of the fast capacitor discharge time into an already established inter-electrode conductive path. Finally, the two-stage approach puts more energy into the acoustical pulse and less total energy into the arc when compared to the prior art approach. Less total energy into the arc directly leads to improved electrode life. Furthermore, the compressed acoustic waves depicted inFIG.9are less painful and damaging when applied to tissue. The typical pulse discharge from prior art electrohydraulic systems produce a broad frequency spectrum acoustic wave, typically in the range of 16 Hz to 30 MHz. The long compressive tail906of the acoustic wave is composed of the lower frequency spectrum of the acoustic wave. These low frequency components, at the acoustic pressures that are typically used, are the main source of large cavitation bubbles. These large cavitation bubbles, when generated in tissue, result in pain and tissue damage. Due to the short capacitor discharge and the resulting fast arc, the long compressive tail906of the acoustic wave is compressed. As a result, large cavitation bubbles secondary to a long tail are minimized. In one embodiment, the present shockwave generating systems and apparatuses incorporate the probes depicted inFIGS.10-12C. In this embodiment, probe1000comprises: a housing1002defining a chamber1004and a shockwave outlet1006; a liquid disposed in chamber1004; a plurality of electrodes306(e.g. in spark head or module1008) configured to be disposed in the chamber to define one or more spark gaps; and is configured to be coupled to a pulse generation system (300) configured to apply voltage pulses to the electrodes at a rate of between 10 Hz and 5 MHz. In the embodiment shown, spark head1008includes a sidewall or body1010and a plurality of electrodes306that defined a spark gap. In this embodiment, probe1000is configured to permit liquid to be circulated through chamber1004via liquid connectors or ports1012and1014, one of which is coupled to the spark head1008and the other of which is coupled to housing1002, as shown. In this embodiment, housing1002is configured to receive spark head1008, as shown, such that housing1002and housing1010cooperate to define chamber1004(e.g., such that spark head1008and housing1002include a complementary parabolic surfaces that cooperate to define the chamber). In this embodiment, housing1002and spark head1008includes a channel1016(e.g., along a central longitudinal axis of spark head1008) extending between liquid connector1012and chamber1004and aligned with the spark gap been electrodes306such that circulating water will flow in close proximity and/or through the spark gap. In the embodiment shown, housing1002includes a channel1018extending between liquid connector1014and chamber1004. In this embodiment, housing1010includes a groove1020configured to receive a resilient gasket or O-ring1022to seal the interface between spark head1008and housing1002, and housing1002includes a groove1024configured to receive a resilient gasket or O-ring1026to seal the interface between housing1002and cap member1028when cap member1028is secured to housing1002by ring1030and restraining collar1032. In the embodiment shown, electrodes306each includes a flat bar portion1034and a perpendicular cylindrical portion1036(e.g., comprising tungsten for durability) in electrical communication (e.g., unitary with) bar portion1034such that cylindrical portion1036can extend through a corresponding opening1038in spark head1008into chamber1004, as shown. In some embodiments, part of the sides of cylindrical portion1036can be covered with an electrically insulative and/or resilient material (e.g., shrink wrap) such as, for example, to seal the interface between portion1036and housing1010. In this embodiment, housing1010also includes longitudinal grooves1038configured to receive bar portions1034of electrodes306. In the embodiment shown, housing1002also includes set screws1040positioned to align with cylindrical portions1036of electrodes306when spark head1008is disposed in housing1000, such that set screws1040can be tightened to press cylindrical portions1036inward to adjust the spark gap between the cylindrical portions of electrodes306. In some embodiments, spark head1008is permanently adhered to housing1002; however, in other embodiments, spark head1008may be removable from housing1002such as, for example, to permit replacement of electrodes306individually or as part of a new or replacement spark head1008. The above specification and examples provide a description of the structure and use of exemplary embodiments. Although certain embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the scope of this invention. As such, the various illustrative embodiments of the present devices are not intended to be limited to the particular forms disclosed. Rather, they include all modifications and alternatives within the scope of the claims, and embodiments other than the one shown may include some or all of the features of the depicted embodiment. For example, components may be combined as a unitary structure. Further, where appropriate, aspects of any of the described examples may be combined with aspects of any of the other described examples to form further examples with comparable or different properties and addressing the same or different problems. Similarly, the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. The claims are not intended to include, and should not be interpreted to include, means-plus- or step-plus-function limitations, unless such a limitation is explicitly recited in a given claim using the phrase(s) “means for” or “step for,” respectively. REFERENCES The following references, to the extent that they provide exemplary procedural or other details supplementary to those set forth herein, are specifically incorporated herein by reference.[1] Raymond L. Boxman, Philip J. Martin, David Sanders (1995).Handbook of Vacuum Arc Science and Technology: Fundamentals and Applications, Park Ridge, N.J.: Noyes Publications, pp. 316-319[2] V. Ya. Ushakov, et al. (2007).Impulse Breakdown of Liquids, New York, N.Y.: Springer[3] Schmitz C, et al. Treatment of chronic plantar fasciopathy with extracorporeal shock waves (review). Journal of Orthopaedic Surgery and Research 2013 8:31[4] U.S. Pat. No. 8,672,721 entitled “High power discharge fuel igniter” by L. Camilli[5] U.S. Pat. No. 5,245,988 entitled “Preparing a circuit for the production of shockwaves” by W. Einars, et al.[6] U.S. Pat. No. 4,005,314 entitled “Short pulse generator” by M. Zinn[7] German Patent No. DE 3150430 C1 entitled “Circuit for generating an underwater discharge” by G. Heine, et al.[8] U.S. Pat. No. 3,604,641 entitled “Apparatus for hydraulic crushing” by B. R. Donoghue, et al.

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DETAILED DESCRIPTION Electrosurgical forceps often include a pivoting mechanism allowing jaws of the forceps to move between open and closed positions. In some examples, frames of the jaws can be driven, such as by a shaft, using a camming mechanism to move between the open and closed positions. Often the camming features of the jaws are positioned at or near a proximal end of the jaw frames to allow the jaws to wide enough to receive tissue therein. Because the camming features are located at a proximal portion of the jaws (often proximal of a pivot point of the jaws), a distal portion of the jaws can exert a lower clamping force than a proximal portion of the jaws. That is, a clamping or closing force applied by the jaws has a distribution as the jaws extend proximally to distally. The present disclosure can help to address these issues by including one or more actuator arms connected to one or more shafts of the forceps and engaged with the jaws, respectively. Each actuator arm can be configured to apply a force on a first jaw towards the second jaw and a force on the second jaw towards the first jaw. The forces can be applied to a portion of the jaw that is distal of the pivot point, helping to increase the closing force at medial and distal portions of the jaws. The above discussion is intended to provide an overview of subject matter of the present patent application. It is not intended to provide an exclusive or exhaustive explanation of the invention. The description below is included to provide further information about the present patent application. FIG.1illustrates a side view of a forceps100showing jaws in an open position. The forceps100can include an end effector102, a handpiece104, and an intermediate portion105. The end effector102can include jaws106(including electrodes109), an outer shaft108, an inner shaft110, and a blade assembly112. The handpiece104can include a housing114, a lever116, a rotational actuator118, a trigger120, an activation button122, a fixed handle124aand124b, and a handle locking mechanism126. The housing114can include a first housing portion128, and a second housing portion130.FIG.1also shows orientation indicators Proximal and Distal and a longitudinal axis A1. Generally, the handpiece104can be located at a proximal end of the forceps100and the end effector102can be located at the distal end of the forceps100. The intermediate portion105can extend between the handpiece104and the end effector102to operably couple the handpiece104to the end effector102. Various movements of the end effector102can be controlled by one or more actuation systems of the handpiece104. For example, the end effector102can be rotated along the longitudinal axis A1of the forceps100. Also, the handpiece can operate the jaws106, such as by moving the jaws106between open and closed position. The handpiece104can also be used to operate the blade assembly112for cutting tissue and can operate the electrode109for applying electromagnetic energy to tissue. The end effector102, or a portion of the end effector102, can be one or more of: opened, closed, rotated, extended, retracted, and electromagnetically energized. The housing114can be a frame that provides structural support between components of the forceps100. The housing114is shown as housing at least a portion of the actuation systems associated with the handpiece104for actuating the end effector102. However, some or all of the actuation components need not be housed within the housing114The housing114can provide a rigid structure for attachment of components, but the housing114does not necessarily house the components completely, or can house a portion of one or more of the components. The drive shaft110can extend through the housing114and out of a distal end of the housing114, or distally beyond housing114. The jaws106can be connected to a distal end of the drive shaft110. The outer shaft108can be a hollow tube positioned around the drive shaft110. The shafts108and110can extend along the axis A1. A distal end of the outer shaft108can be located adjacent the jaws106. The distal ends of the drive shaft110and the outer shaft108can be rotationally locked to the jaws106. The rotational actuator118can be positioned around the distal end of the housing114. The outer shaft108can extend distally beyond the rotational actuator118. The blade shaft112bcan extend through the drive shaft110and the outer shaft108. A distal end of the blade shaft112bcan be located near the jaws106. A proximal end of the blade shaft112bcan be within housing114. The handpiece104can enable a user to extend and retract a blade112aof the blade assembly112, which can be attached to a distal end of a blade shaft112bof the blade assembly112. In some examples, the blade112acan extend an entirety of a length between the handle104and the end effector102. In some examples, the handpiece104can include features that inhibits the blade assembly112from being extended until the jaws106are at least partially closed, or fully closed. The blade112acan be extended by displacing the trigger120proximally and the blade112acan be retracted by allowing the trigger120to return distally to a default position. A proximal portion of the trigger120can be connected to the blade shaft112bwithin the housing114and a distal portion of the trigger120can extend outside of the housing114adjacent to, and in some examples nested with, the lever116in the default or unactuated positions. The activation button122can be coupled to the housing114and can include or be connected to electronic circuitry within the housing114. Such circuitry can send or transmit electromagnetic energy through forceps100to the jaws106. In some examples, the electronic circuitry may reside outside the housing114but can be operably coupled to the housing114and the end effector102. In operation of the forceps100, a user can displace the lever116proximally by applying a Force F1to the lever116to actuate the drive shaft110to drive the jaws106from the open position (FIG.2A) to the closed position (FIGS.2B and2C), which can allow the user to clamp down on and compress a tissue. The handpiece104can also allow a user to rotate the rotational actuator118to cause the end effector102to rotate, such as by rotating both the drive shaft26and the outer shaft28together. In some examples, with the tissue compressed, a user can depress the activation button122to cause an electromagnetic energy, or in some examples, ultrasound, to be delivered to the end effector102, such as to the electrode109and to the tissue. Application of such energy can be used to seal or otherwise affect the tissue being clamped. In some examples, the electromagnetic energy can cause tissue to be coagulated, sealed, ablated, desiccated or can cause controlled necrosis. When desired, the trigger120can be moved to translate the blade assembly112distally such that the blade112acan extend between the jaws106in order to cut the tissue within the jaws106. Such a process can be repeated, as desired. In some examples, the forceps100, or other medical device, may not include all the features described or may include additional features and functions, and the operations may be performed in any order. The handpiece104can be used with a variety of other end effectors to perform other methods. FIG.2Aillustrates an isometric view of a portion of forceps200in an open position.FIG.2Billustrates an isometric view of a portion of the forceps200in a closed position.FIG.2Cillustrates an isometric view of a portion of the forceps200in a closed position.FIGS.2A-2Care discussed together below. The forceps200can include jaws206aand206b, an outer shaft (or first shaft)208, an inner shaft (or second shaft)210, actuator arms232aand232b, and a cam feature (or cam pin)233. The first jaw206acan include a grip plate207a, an electrode209a, a frame234a, and an insulator236a. The grip plate207acan define an actuator track238aincluding a distal portion240a. The frame234acan include a cam interface (or track or slot)242aincluding a distal portion244aand the frame234acan include a drive connection246a. Similarly, the second jaw206bcan include a grip plate207b, an electrode209b, a frame234b, and an insulator236b. The grip plate207bcan define an actuator track238bincluding a distal portion240b. The frame234bcan include a cam interface (or track or slot)242bincluding a distal portion244band the frame234bcan include a drive connection246b. The outer shaft208can include outer arms248. The inner shaft210can include a head250, and a connector252. The forceps can also include arm retainers254aand254b. The forceps200can be similar to the forceps100; additional details are discussed below with respect to the forceps200. Any of the components of the forceps200can be comprised of materials such as one or more of metals, plastics, foams, elastomers, ceramics, composites, combinations thereof, or the like. Materials of some components of the forceps200are discussed below in further detail. The jaws206aand206b(collectively referred to as jaws206) can be rigid or semi-rigid members configured to engage tissue. The jaws206aand206bcan be coupled to the inner shaft210, such as pivotably coupled, via the connectors252. The connectors252can be one or more pins, bosses, or the like and can be configured to extend through the drive connections246aand246bof the jaws206aand206b, respectively, such as when the drive connections246are bores extending through the jaw frames234, to pivotably couple the frames234to the first shaft208. The drive connections246can be other tracks, fasteners, or connectors in other examples. In some examples, the jaws206aand206bcan be pivotably coupled to the outer shaft210via one or more pin, boss or connector. The grip plates207aand207bof the jaws206aand206b, respectively, can each be a rigid or semi-rigid member configured to engage tissue and/or the opposing jaw to grasp tissue, such as during an electrosurgical procedure. One or more of the grip plates207aand207bcan include one or more of serrations, projections, ridges, or the like configured to increase engagement pressure and friction between the grip plates207aand207band tissue. The jaws206aand206bcan include electrodes209aand209bconfigured to deliver electricity to tissue (optionally through the grip plates207aand207b), and optionally through the frames234aand234b, respectively. The frame234aof the upper jaw206acan extend proximally away from the grip plate207a, and in some examples, downward when the upper jaw206ais in the open or partially open positions (as shown inFIG.2A). Similarly, the frame234bof the lower jaw206bcan extend proximally away from the grip plate207b, and in some examples, substantially upward when the upper jaw206ais in the open position or the partially open position (as shown inFIG.2A). The insulators236aand236bcan be made of electrically insulative material such as one or more of polymers, glasses, rubbers, combinations thereof, or the like. The insulators236aand236bcan be positioned over the grip plates207aand207band can be connected to the frames234aand234bto connected the frames234aand234bto the grip plates207aand207b, respectively, while electrically isolating the grip plates207aand207bfrom the frames234aand234bto help limit electric current from flowing from the electrodes209aand209band the grip plates207aand207bto the frames234aand234b, which can help prevent electricity from being delivered to incorrect components during coagulation operation (deliver of energy to the electrodes209) of the forceps200. The actuator arms232aand232bcan be flexible or semi-rigid members connected to the outer shaft208via the arm retainers254aand254bat a proximal portion of the actuator arms232aand232b, respectively. The actuator arms232can be made of resilient materials such as spring steel, Nickel Titanium (Nitinol), or the like such that the actuator arms232can be configured to elastically bend or flex such as being configured to bow laterally outward with respect to the jaws206. In some examples, the actuator arms232aand232bcan be made of non-spring (or reduced spring) materials, such as one or more of polymer, steel, aluminum, titanium, or the like. Distal portions256aand256bof the actuator arms232aand232bcan be positioned in the actuator tracks238aand238b, respectively, and the actuator tracks238can be translatable or movable relative to the arms232, as discussed in further detail below. The arm retainers254can be pins, screws, bosses, or other fasteners configured to connect the actuator arms232to the shaft. In some examples, the arm232acan be connected to the retainer254aat a top portion (or laterally outer portion) of the outer shaft208and the arm232bcan be connected to the retainer254bat a bottom portion (or laterally outer portion opposite the retainer254a) of the outer shaft208, which can help provide clearance for components, such as a blade, to pass between the retainers254. The grip plate207a, such as a top, superior, or laterally outer portion of the grip plate207a, can define the actuator track238a. Similarly, the grip plate207b, such as a top, superior, or laterally outer portion can define the actuator track238b. The actuator tracks238aand238bcan be similar but orientated in opposite directions. In other examples, the actuator tracks238aand238bcan be the same. The actuator track238acan extend along a top portion of the grip plate207aand can include a distal portion240awhich can define a distal termination of the actuator track238a. A proximal portion can similarly define a proximal termination of the actuator track238a. In some examples, the proximal portion of the actuator track238acan be open. The actuator track238acan be configured to receive and retain a portion of the actuator arm232atherein. During operation, the distal portion256aof the actuator arm232acan be configured to engage a distal portion240aof the actuator track238a, as discussed in further detail below. The actuator track238bcan be similarly configured to the actuator track238a. The outer shaft208, which can be similar to the shaft108discussed above, can include the outer arms248, that can extend distally and can have a height that is smaller than a diameter of the outer shaft208. The outer arms248can be connected to the cam feature233, which can extend between the outer arms248. The cam feature233can be a pin, boss, bosses, or other projection or protuberance. In some examples, the cam feature233can be a track and a boss or pins can extend from the frames234aand234binto cam features233of the outer arms248. In examples where the cam feature233is a pin or bosses it can extend from the outer arms248and can extend into or through the cam interfaces242aand242bof the frames234aand234bof the jaws206aand206b, respectively. The cam interfaces242can be tracks or slots in some examples and can be movable along the cam feature233. The inner shaft210can be positioned within the outer shaft208and can be configured to translate (or move) substantially proximally and distally therein. The head250can be located at a distal portion of the inner shaft210and can have a relatively larger diameter such as to help limit non-translational movement (e.g., lateral movement) of the inner shaft210with respect to the outer shaft208. The connector252(or connectors252) can be connected to the head250and can be connected to the frames234aand234bvia the drive connections246aand246bof the frames234aand234b, respectively. In operation of some examples, the forceps can be in an open position where a proximal portion of the cam interfaces242aand242bare engaged with the cam feature233such that the jaws206aand206bare in the open position, as shown inFIG.2A. Prior to closing, the jaws206aand206bcan be in partially open or partially closed positions between the positions shown inFIGS.2A and2B. In such a position, the inner shaft210can be in a distal position relative to the outer shaft208(or distal of a proximal-most position). In some examples, one jaw, such as the jaw206b, can be fixed with respect to the outer shaft208. In such an example, only the jaw206amay move and a partially open position can be a position where the jaw206amoves away from the jaw206band an open position can be where the jaw206ais limited from opening further such as via contact between the cam interface242aand the cam feature233. Closing of the jaw206ain a single acting configuration can include movement of the jaw206awith respect to the outer shaft210and with respect to the jaw206b. That is, in some examples, one of the jaws206(such as the jaw206b) can be fixed with respect to one of the inner shaft210and the outer shaft208, where the other jaw (206a) can be movable with respect to the inner shaft210, the outer shaft208, and the jaw206b. In a dual-acting configuration, when it is desired to close the jaws206, a handle (such as the lever116) can be operated to cause the inner shaft210and the head250to move proximally, causing the frames234aand234bto move proximally. When the frames234move proximally, the cam interfaces242aand242bcan move along the cam feature233to cause the frames234aand234bto move towards each other and therefore to cause the grip plates207to move towards each other. As the inner shaft210pulls the frames234aand234bproximally, the actuator tracks238aand238bcan move proximally with respect to the arms232aand232b, respectively, such that the distal portions240aand240bof the actuator tracks238aand238bcan move towards the distal portions256aand256bof the arms232aand232b, respectively. When the grip plates207aand207bcontact each other the grip plate207acan apply a force (or a closing or clamping force) on the grip plate207band the grip plate207bcan apply a force on the grip plate207b. During continued movement of the inner shaft210, the grip plates207aand207bcan contact each other, as shown inFIG.2B. The cam feature233can be positioned near, but not necessarily at, the distal portions244of the cam guides242. The inner shaft210can be moved further proximally if desired. Such movement can cause the camming feature233to move into the distal portions244where the distal portions244may or may not cause further movement of the frames234and the grip plates207. Such movement of the frames234can also cause the distal portions240aand240bof the actuator tracks238aand238bto move proximally towards the distal portions256aand256bof the actuator arms232aand232bto eventually engage the distal portions256aand256b, where the cam feature233can be still spaced away from a termination of the distal portions244of the cam guides242. Because the actuator arms232aand232bare fixed to the outer shaft208, when the distal portions256aand256bof the actuator arms232aand232bengage the distal portions240of the actuator tracks238aand238b, respectively, and because the cam feature233can be still spaced away from a termination of the distal portions244of the cam guides242(as shown inFIG.2B), force applied by continuing proximal movement of the inner shaft208with respect to the outer shaft210can be applied or transferred from the distal portions240of the actuator tracks238to the distal portions256aand256bof the actuator arms232aand232b. And, because the actuator arms232aand232bcan be resilient members, the force applied by the distal portions240of the actuator tracks238can cause the actuator arms232aand232bto flex or bend (as shown inFIG.2C), effectively causing, for example, a medial or middle portion of the actuator arms232aand232bto bow outward (e.g., laterally). This movement or flex of the actuator arms232aand232bcan be elastic deformation of the actuator arms232aand232band can result in a force directed laterally inward and applied from the actuator arm232ato the grip plate207ato help increase the closing force applied by the grip plate207ato the grip plate207b. Similarly, actuator arm232bcan apply a force on the grip plate207bto help increase the closing force applied by the grip plate207bto the grip plate207a. The actuator arms232aand232bcan thereby increase the closing force applied by the grip plates207aand207bto each other (and to anything between the grip plates, such as tissue). In some examples, a location of the distal portions240of the actuator tracks238can be more than halfway past a distal to proximal midpoint of the grip plates207, which can help to increase a closing force at distal portions of the grip plates207. In another example, the outer shaft208can be moved with respect to the inner shaft210, which can allow a position of the jaws206to remain fixed with respect to the handpiece104. More specifically, when it is desired to close the jaws206, a handle (such as the lever116) can be operated to cause the outer shaft208to move distally, causing the camming feature233to move distally. When the camming feature233moves distally, the cam interfaces242aand242bcan move along the cam feature233to cause the frames234aand234bto move towards each other and therefore to cause the grip plates207to move towards each other. As the outer shaft208moves distally, the outer shaft can move the arms232aand232bdistally with respect to the actuator tracks238aand238b, such that the distal portions256aand256bof the arms232aand232bcan move towards the distal portions240aand240bof the actuator tracks238aand238b, respectively. When the grip plates207aand207bcontact each other the grip plate207acan apply a force (or a closing or clamping force) on the grip plate207band the grip plate207bcan apply a force on the grip plate207b. During continued movement of the outer shaft208, the grip plates207aand207bcan be in contact with each other. The cam feature233can be positioned near, but not necessarily at, the distal portions244of the cam guides242. The outer shaft208can be moved further distally, if desired. Such movement can cause the camming feature233to move into the distal portions244where the distal portions244may or may not cause further movement of the arms232and the grip plates207. When the arms232move further distally, the distal portions distal portions256aand256bof the actuator arms232aand232bcan continue to move distally toward the distal portions240aand240bof the actuator tracks238aand238bto eventually engage the distal portions256aand256b, where the cam feature233can be still spaced away from a termination of the distal portions244of the cam guides242. Because the actuator arms232aand232bare fixed to the outer shaft208, when the distal portions256aand256bof the actuator arms232aand232bengage the distal portions240of the actuator tracks238aand238b, respectively, and because the cam feature233can be still spaced away from a termination of the distal portions244of the cam guides242, force applied by continuing distal movement of the outer shaft210with respect to the inner shaft208can be applied or transferred from the distal portions256aand256bto the distal portions240of the actuator tracks238. And, because the actuator arms232aand232bcan be resilient members, the force applied can cause the actuator arms232aand232bto flex or bend, effectively causing, for example, a medial or middle portion of the actuator arms232aand232bto bow outward (e.g., laterally). This movement or flex of the actuator arms232aand232bcan be elastic deformation of the actuator arms232aand232band can result in a force directed laterally (e.g., inward) and applied from the actuator arm232ato the grip plate207ato help increase the closing force applied by the grip plate207ato the grip plate207b. Similarly, actuator arm232bcan apply a force on the grip plate207bto help increase the closing force applied by the grip plate207bto the grip plate207a. The actuator arms232aand232bcan thereby increase the closing force applied by the grip plates207aand207bto each other (and to anything between the grip plates, such as tissue). As discussed above, either of the shafts208and210can be moved relative to the other shaft and to the handpiece104to operate the jaws206and the arms232to close the jaws206and apply a closing force to the jaws206by the arms232. In some examples, the actuator arms232can be configured to apply a force on the jaws206when the jaws move out of the open position (as shown inFIG.2A). FIG.3illustrates an isometric view of a portion of the forceps200in a closed position. The forceps200ofFIG.3can be consistent with the forceps ofFIGS.1-2Bdiscussed above. Additional details of the forceps are shown inFIG.3. For example,FIG.3shows that the actuator arm232acan include a first arm258aand a second arm258bwhich can be connected to the distal portion256a.FIG.3also shows that the actuator track238acan include an opening260a. The opening260acan be configured to receive the distal portion256atherein and the arms258aand258bcan be positioned laterally outward of the track238asuch that movement of the track238awith respect to the arm232ais guided by the distal portion256a. The opening260aof the actuator track238acan be positioned such that the distal portion240ais proximal of the distal portion256aof the actuator arm232awhen the jaws206are in the fully open position (as shown inFIG.2A) to help prevent the distal portion256afrom escaping the actuator track238aduring operation while also providing an opening for inserting the distal portion256ainto the actuator track238aduring assembly of the forceps200. The actuator arm232band the jaw206bcan be similarly configured to the actuator arm232aand the jaw206a. FIG.3also shows that the blade212can extend through the internal shaft210and the external shaft208. The blade212can also extend between the retainers254aand254b. Also, the blade212can include a slot262(shown inFIG.2A) that allows the cam feature233(and optionally the connector252) to extend through the blade212. In other examples, the cam feature233can be multiple bosses or projections such that the slot262of the blade212can be omitted. FIG.4illustrates an exploded isometric view of the forceps200. The forceps200ofFIG.4can be consistent with the forceps ofFIGS.1-3discussed above. Additional details of the forceps are shown inFIG.4. For example,FIG.4shows arm connectors266aand266bof the actuator arms232aand232b, respectively. The connectors266can be curved or rounded portions of the arms232configured to receive and retain at least a portion of the arm retainers254aand254b, respectively, to secure the actuator arms232aand232bto the outer shaft208. FIG.4also shows that the grip plates207aand207bcan include a conductive portion268aand268b, respectively, and an insulative portion270aand270b. The conductive portions268aand268bcan be connected to the insulative portions270aand270b, respectively. The conductive portions268can be made of electrically conductive materials such as one or more of copper, silver, aluminum, or the like. The insulative portions270can be made of less conductive, or electrically insulative materials such as one or more of polymer, glass, rubber, ceramic, or the like. Because the insulative portions270are connected to the actuator arms232, the insulative portions270can help prevent electricity from flowing from the electrodes209to the grip plates207to the conductive portions268to the actuator arms232and to the outer shaft208, which could cause a short circuit for the electrodes209. FIG.4also shows that the frame234bcan include a first member272and a second member274which can be substantially parallel and can be spaced from each other. Each member can include the cam interface242band the drive connection246b. In some examples, the members of the frame234acan be wider (laterally) than the members of the frame234b. In some examples, the members of the frames234can have similar or the same widths but the members can be interlaced or offset. In some examples, the frames234can include only one member.FIG.4also shows that the head250of the inner shaft210can include a blade passage276for guiding a blade through the inner shaft210. NOTES AND EXAMPLES The following, non-limiting examples, detail certain aspects of the present subject matter to solve the challenges and provide the benefits discussed herein, among others. Example 1 is a surgical forceps comprising: a first shaft extending longitudinally; a cam feature connected to the first shaft; a first jaw defining a cam interface and an actuator track, the cam interface engaged with the cam feature, and the first jaw movable between an open position and a closed position; a second jaw engaged with the first shaft and opposing the first jaw, the first jaw movable relative to the second jaw; an actuator arm including: a proximal portion connected to the first shaft; and a distal portion located at least partially in the actuator track of the first jaw and configured to apply a closing force on the first jaw when the first jaw is moved out of the open position; and a second shaft connected to the first jaw, the second shaft translatable relative to the first shaft to move the cam feature along the cam interface of the first jaw to move the first jaw between the open position and the closed position, and translatable to move the actuator arm relative to the actuation track between a proximal position and a distal position, the actuator arm configured to increase the closing force as the actuator arm is moved from the proximal position to the closed position. In Example 2, the subject matter of Example 1 optionally includes wherein the cam interface includes a distal portion configured to receive the cam feature therein when the second shaft moves proximal of the proximal position. In Example 3, the subject matter of Example 2 optionally includes wherein the distal portion of the actuator arm is configured to engage the actuator track to limit distal movement of the actuator arm relative to the actuation track and the first jaw. In Example 4, the subject matter of Example 3 optionally includes wherein the actuator arm is configured to increase the closing force applied to by the first jaw when the distal portion of the actuator arm engages the actuator track and when the cam feature is in the distal portion of the cam interface. In Example 5, the subject matter of Example 4 optionally includes wherein the actuator arm is configured to flex to apply the closing force to the second jaw. In Example 6, the subject matter of Example 5 optionally includes wherein the actuator arm is a biasing element. In Example 7, the subject matter of any one or more of Examples 5-6 optionally include wherein the actuator arm is made of spring steel. In Example 8, the subject matter of any one or more of Examples 1-7 optionally include wherein the cam interface is a first cam interface and the actuator track is a first actuator track, wherein the second jaw defines a second cam interface and a second actuator track, wherein the cam feature is engaged with the first cam interface and the second cam interface, and wherein the second shaft is connected to the first jaw and the second jaw and is configured to move the cam feature along the first cam interface and the second cam interface to move the first jaw and to move the second jaw with respect to the first shaft between open and closed positions. In Example 9, the subject matter of Example 8 optionally includes a second actuator arm including: a second proximal portion connected to the first shaft; and a second distal portion located at least partially in the second actuator track of the second jaw and configured to apply a second closing force on the second jaw when the second jaw is moved out of the open position. In Example 10, the subject matter of any one or more of Examples 1-9 optionally include wherein the cam feature is a cam pin and wherein the cam interface is a cam track. Example 11 is a surgical forceps comprising: a first shaft extending longitudinally; a cam pin; a first jaw engaged with the first shaft and defining a cam track and an actuator track, the cam track engaged with the cam pin, and the first jaw movable between an open position and a closed position; a second jaw engaged with the first shaft and opposing the first jaw; an actuator arm including: a proximal portion; and a distal portion located at least partially in the actuator track of the first jaw and configured to apply a closing force on the first jaw when the first jaw is moved out of the open position; and a second shaft translatable relative to the first shaft to cause relative movement of the cam track of the first jaw with respect to and along the cam pin to move the first jaw between the open position and the closed position, and the second shaft translatable to move the actuation track relative to the actuator arm to cause engagement between the actuation track and the actuator arm to increase the closing force. In Example 12, the subject matter of Example 11 optionally includes wherein the cam track includes a distal portion configured to receive the cam pin therein. In Example 13, the subject matter of Example 12 optionally includes wherein the distal portion of the actuator arm is configured to engage the actuator track to limit proximal movement of the actuator track relative to the actuator arm and the first jaw. In Example 14, the subject matter of Example 13 optionally includes wherein the actuator arm is configured to increase the closing force applied to by the first jaw when the distal portion of the actuator arm engages the actuator track and when the cam feature is in the distal portion of the cam interface. In Example 15, the subject matter of Example 14 optionally includes wherein the actuator arm is configured to flex to apply the closing force to the second jaw. Example 16 is a surgical forceps comprising: a first shaft extending longitudinally; a cam feature connected to the first shaft; a first jaw defining a first cam interface and a first actuator track, the first cam interface engaged with the cam feature; a second jaw defining a second cam interface and a second actuator track, the second cam interface engaged with the second cam feature, and the first jaw and the second jaw movable relative to the first shaft between an open position and a closed position; first and second actuator arms including: a proximal portion connected to the first shaft; and a distal portion located at least partially in the actuator track of the first jaw and the second jaw, respectively, and configured to apply a closing force on the first jaw and the second jaw, respectively, when the first jaw and the second jaw are moved out of the open position; and a second shaft connected to the first jaw and the second jaw, the second shaft translatable relative to the first shaft to move the first cam interface of the first jaw and the second cam interface of the second jaw along the cam feature to move the first jaw and the second jaw between the open position and the closed position. In Example 17, the subject matter of Example 16 optionally includes wherein the second shaft is translatable to move the actuation track relative to the first actuator arm and the second actuator arm between proximal positions and distal positions, the first actuator arm configured to increase the closing force as the first actuation track is moved from the distal position to the proximal position. In Example 18, the subject matter of Example 17 optionally includes wherein the second actuator arm is configured to increase the closing force as the second actuation track is moved from the distal position to the proximal position. In Example 19, the subject matter of any one or more of Examples 16-18 optionally include wherein the distal portions of the first actuator arm and the second actuator arm are configured to engage the first actuator track and the second actuator track, respectively, to limit proximal movement of the first actuator track and the second actuator track relative to the first actuator arm and the first jaw and the second actuator arm and the second jaw, respectively. In Example 20, the subject matter of Example 19 optionally includes wherein the first actuator arm and the second actuator arm are configured to increase the closing force applied to by the first jaw and the second jaw, respectively, when the distal portions of the first actuator arm and the second actuator arm engage the first actuator track and the second actuator track, respectively, and when the cam feature is in the distal portions of the first cam interface and the second cam interface. In Example 21, the apparatuses or method of any one or any combination of Examples 1-20 can optionally be configured such that all elements or options recited are available to use or select from. The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention can be practiced. These embodiments are also referred to herein as “examples.” Such examples can include elements in addition to those shown or described. However, the present inventors also contemplate examples in which only those elements shown or described are provided. Moreover, the present inventors also contemplate examples using any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein. In the event of inconsistent usages between this document and any documents so incorporated by reference, the usage in this document controls. In this document, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, a system, device, article, composition, formulation, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is provided to comply with 37 C.F.R. § 1.72(b), to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description as examples or embodiments, with each claim standing on its own as a separate embodiment, and it is contemplated that such embodiments can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

11857214

DESCRIPTION OF THE EMBODIMENTS Reference will now be made in detail to embodiments of the disclosure, an example of which is illustrated in the accompanying drawings. For convenience, the term “tissue grasper” will be used throughout this application. Overview The present disclosure provides a tissue grasper including two arms forming a jaw-like structure. The tissue grasper may be an end-effector for holding tissue and other target objects. The arms of the end-effector may be rotatably connected to one another to permit the arms to move between an open and closed configuration. A proximal portion of one or both arms may be operable connected to a control member. The control member extends through an elongated member extending between the end-effector at its distal end to an end-effector actuator means (hereafter, controller) present at its proximal end. Articulating the controller actuates the end-effector to effectuate opening and closing of the arms. The two arms may be differentiated as an “upper” and “lower” jaw. Various configurations of end-effector actuation, structure, and functions are described in the embodiments of the disclosure. Further, as used in this disclosure, “distal” refers to a position or direction further from the user, and “proximal” refers to a position or direction opposite “distal” and closer to the user. More particularly, the present disclosure provides a tissue-grasping device for securely holding and manipulating tissues. Manipulation includes, but is not limited to, cutting, sectioning, stapling, clamping, cauterizing, grasping, holding, or scraping of tissue. Clamping as used in this disclosure means holding, grasping, and/or fastening tissues together. The various methods of manipulation are described in detail hereafter. Exemplary Embodiments FIG.1Adepicts a tissue grasper100in an open configuration according to an embodiment of the present disclosure. The tissue grasper100includes an end-effector101extending distally from an elongated member102. A control member (not shown) extends through the elongated member102translating the movements from a controller or handle (not shown) present at the proximal end of the elongated member102. The elongate member102includes a clevis member103that is present at its distal end. The end-effector101includes two jaws or arms, an upper arm104A and a lower arm104B, (hereafter, arms104) pivotally connected to each other. The jaws may be pivotably coupled to the clevis103, for example, via a pivot pin113. A proximal end105of arms104may be rotatably connected to one another to permit arms104to move between them. A control member (not shown) may be operably connected to the proximal end105of one or both of arms104, so that actuating the arms104at their proximal end105translates into movement of the arms104at their distal end106. While both arms104may be pivotable relative to one another, in some embodiments, one of the arms104may be fixed, and the other arm104may be movable, so the control member actuates only the movable arm104. The cross section of the arms104may also vary on their proximal and distal ends105,106. The distal end106of the arms104includes an inner surface107, and an outer surface108. As shown inFIG.1, inner surface107is a tooth-type or ridge-like mating surface, thereby forming a substantial tissue contacting area to increase gripping and friction applied to the tissue, to reduce the likelihood of the grasped tissue from slipping. In some embodiments, the tissue contacting area may be substantially flat. At their distal ends106, arms104may be linear, as shown inFIG.1, but in alternate embodiments, the arms104may also be curved. In some embodiments, inner surface107may include surface roughening to enhance friction for improved tissue grasping. In addition, any suitable surface of arms104may include any desired surface roughening. In additional embodiments, as shown inFIGS.1B-1Dthe distal end106of the upper arm104A may be varied in shapes and sizes.FIG.1Bdepicts a spear headed tip114, which may be used in skewering obstructing or unwanted tissues. The sharp end may also be used to tear open tissues to reach otherwise inaccessible areas within the body. The distal end106may also be shaped as a curved beak115like structure as depicted inFIG.1C. Alternatively, the distal end may be tapered laterally giving rise to a flattened edge116as shown inFIG.1D. The flattened edge116may also be beveled to prevent injury to the tissue. The modified distal ends114,115and116may also be used for scraping plaque or debris adhered to the tissue. The modified distal ends114,115,116may also be used as a wedge to separate tissue layers or to single out vascular structures from a bundle. The distal end modifications may be present on the lower arm104B or on both the arms104. In some embodiments, spear headed tip114may include a flat, elongated edge that may aid in scraping or cutting. For example, rather than tip114, a distalmost end of one or more of arms104may be formed as a flat edge. The inner surfaces107of the arms104comprise ridges109and grooves110of suitable dimension. The cross section of the ridges109may be an angular slope, such as “V” shaped ridges109. Alternatively, in other embodiments, the cross section of the ridges109may be rectangular, semicircular, or a combination of shapes. The ridges109may also lie parallel to one another on any axis in a lateral plane. Additionally, the ridges109may also be intersecting each other. The grooves110may also intersect with one another at any desired angle. Further, the ridges109may be present on at least one of the distal ends106of the arms104. Alternatively, the ridges109may be present on both arms104, seated within grooves110on the ridges109. The ridges may vary in shape or dimension, and the inner surfaces107may provide corresponding grooves110to accommodate the ridges109. Further, ridges109may have different heights, widths, and lengths. The inner surface107on at least one of the arms104may also include bisection along the length of the arm104. The bisection may take the form of a channel111, allowing an element such as a blade to advance to the distal end106. The channel111may also be present on both the inner surfaces107, and may be of similar or different dimensions. The lumen and channel may consist of an opening for passage of exemplary tools through the device by the user. Such exemplary tools may include, but are not limited to, one or more needles, blades, or cautery tools. The channel may run parallel to the longitudinal axis, may be present at an angle, or may have a curve or bend. The embodiment shown inFIGS.1A-Dalso includes an advancing member, such as a cautery blade in the form of a cutter tool112. In addition, the cutter tool112may be any other cautery tool, such as an electrocautery blade, a coagulation forceps, suction cautery devices, laparoscopic electrodes, laser fibers, lithotripters, and electrode cautery tips, which may include ball-tip, needle, and extended or flat blade electrodes. Further, the embodiments ofFIGS.1A-Dmay include any suitable suction and/or irrigation device. In some embodiments, the advancing member may include one or more channels, having a desired configuration, running at least partially along the length of the advancing member. For example, the channel may run parallel to the advancing member. Alternatively, the channel may be angled or curved with respect to the advancing member. As shown inFIG.1B, the cutter tool112may be a cautery blade, which is present at the proximal side of the distal end of the arm. The cutter tool112may be connected to a control member (not shown), and may be actuated by articulating the controller present at the proximal end of the control member. If connecting cutter tool112to the existing controller proves inconvenient, then an additional control member may be provided. The cutter tool112may be advanced or retracted along the length of the inner surface107, with the dimensions of the tool being accommodated within the channel111bisecting the inner surface107. Tissue or vessel excision may lead to blood loss and further complications during surgery. The tissue grasper100with the integrated cutter tool112may allow for cauterizing tissue present within the arms104of the tissue grasper100, thereby preventing slippage of the ends of the cut tissue. This may especially be useful in the case of blood vessels and ducts. In some embodiments, a cautery tool (e.g., an electrocautery blade) may be able to operate cold for cutting. That is, energy may not be required for cutting of tissue. However, in some cases, energy may be applied either to improve cutting or to contain bleeding through cauterization of tissue. The cutter tool112may be replaced by a suction tool in some embodiments. The suction tool may be shaped similar to a Touhy needle, which can penetrate the grasped tissue and drain the fluids trapped within it. The suction tool may be in turn connected to a vacuum pump. In addition, the cutter tool112may be replaced by an irrigation tool for connection to an irrigation pump. The irrigation tool may be used to flush, e.g., tissue or other bodily matter from the treatment site. The tissue grasper100may also integrate a tissue stapling or fastening means (not shown). Tissue stapling comprises a stapling element that may be disposed on at least one of inner surfaces107. In another embodiment (not shown), two interlocking pieces of a stapling means are disposed on the two inner surfaces107. When tissue is grasped between the open arms104, the staple may be inserted and secured in place by the force provided during the closure of the arms104. The stapling driving and forming operation could also be achieved by the advancing forward, i.e., proximal to distal, or by pulling rearward, i.e., distal to proximal, of a staple driving mechanism. The tissue grasper100may also include a clamping element (not shown), which may be a “U” shaped elongate structure whose ends may be compressed towards one another and locked to form a fastening or sealing structure. In one embodiment, a clamp may be disposed between the distal ends106of the arms104, wherein the clamp ends are towards the distal end106. When tissue is grasped between the open arms104, the clamp may be tightened and the ends secured in place by the force provided during the closure of the arms104. Further modifications to the inner surface107are hereafter provided in the additional embodiments of this disclosure. The outer surface108of the distal end106may be of any suitable shape that provides an atraumatic surface, such as beveled edges and rounded corners, to soft tissue. If desired, the end-effector101can be completely retracted into a protective sheath (not shown), and in one embodiment, the end-effector101can be completely withdrawn into an endoscope or similar instrument (not shown). The retracted configuration could prove useful for moving the unit through a patient's body lumens in preparation for use. As described above, cauterization features may be incorporated by use of an electrocautery blade. In this embodiment, the inner surface107is formed of insulated or non-conductive material, for example, ceramic, plastic or any other suitable material known in the art. In other embodiments, the outer surface108may be made of any rigid material, such as metals, plastics, ceramics, or any other suitable material, which is biocompatible, and atraumatic to tissues. The outer surface108may also be coated with radio opaque materials, such as metals. Alternatively, the plastic or ceramic components may be ingrained with metal particulates to improve radio visibility. Power may be supplied to the electrocautery blade through an additional channel (not shown) provided in elongated member102. As best seen inFIG.1, the inner surface107is oriented at an angle relative to the axis A-A′ of the elongated member102. In this embodiment, the inner surface107is at an angle θ, however, in other embodiments, angle θ may be more or less than 90 degrees. Further, although angle θ is substantially the same in each arm104, it should be appreciated that angle θ may be the same or different for one or more arms104. Inner surface107engages and grasps the tissue segments that are retained within the space between arms104. To enhance the grasping of the tissue segments within the space, angle θ may be less than or equal to 90 degrees. In additional embodiments, the distal end106of the upper arm104A may include a curved end. The end may be tapering in all directions leading to a spear headed tip114as shown inFIG.1B. The spear headed tip114may be useful in skewering obstructing tissues. The spear headed tip114may also be curved to form a beak like structure as shown inFIG.1C. Alternatively, the distal end106may be tapered laterally giving rise to a flattened edge116as shown inFIG.1D. The edge may also be blunt and beveled to prevent injury to the tissue. The modified distal ends114,115,116may also be used for scraping plaque or debris adhered to the tissue. The flattened edge116may also be used as a wedge to separate tissue layers or to single out vascular structures from a bundle. Any component or the instrument as a whole may include a bipolar construction having areas of opposite polarity with insulation between components. In another embodiment, as shown inFIG.2, the inner surface107of the end-effector101may also include barb-like elements that can be advanced or retracted. The barbed elements (hereafter, projections202) may penetrate the tissue, to provide a better grip on slippery or dense tissue. The projections202, formed as rigid protrusions or extensions, are disposed on at least one of the inner surfaces107. Alternatively, the projections202may be made of flexible material, and may have hooked ends to grab on to tissue. The projections202may also be an actuable element that can be advanced (from below flush with inner surface107) to the desired length for the required tissue engagement, retracted, or held in position. The projections202may also be tubular structures, such as a Touhy needle like structure. The lumen on the tubular structure may be connected to a drainage system or a vacuum suction to drain fluids from grasped tissue. The tubular structures may also inject antiseptic formulations or anesthetics to prevent sepsis and relieve pain. The inner surface107, as shown inFIG.2, also includes ridges109and grooves110, as explained in connection with the first embodiment. The projections202may be advanced through slots (not shown) on the inner surface107. The projections202may be connected to a controller via suitable control members (not shown). In some embodiments, the projections202may be actuated with a wedge-like deployment means within the end-effector, wherein distal movement of wedge pushes the projections up. In case the inner surface107is ridged, the slots may also be present on the ridges109or in the grooves110. In addition, the tissue grasper100as described in this embodiment, may also include the variations described above in connection with the embodiments described inFIG.1for example, the projections202may be present along with a cutter tool112. FIG.3Adepicts a tissue grasper100according to another embodiment of the present disclosure. The inner surface107, as shown inFIG.3, includes ridges109and grooves110, as explained in the previous embodiments. The inner surface107may also be partially ridged. The ridges109may be present at a proximal or distal region, or alternatively may be present on both the proximal and distal regions of the distal end106of the arm104, and there may be a patch of region along the inner surface107that is free from any ridges109(“unridged portion302”) as shown inFIG.3B. The unridged portion302may include a non-slippery surface, which in turn may have a roughened surface to increase friction. The multiple teeth and/or surface configurations could be used for, as an example, grasping different tissue types, including, but not limited to, thick and dense tissue, thick and soft tissue, and thin and light tissue. In addition, grasping other surgical devices such as needles or sutures. The unridged portion302as shownFIGS.3A-Bmay be used as an anvil to strike, for example, a staple, a fastener, or a clip, through the grasped tissue. Staples may be disposed on the inner surface107of the upper arm104A. When the arms104move towards each other the staples may be forced into the tissue. The unridged portion302provides a surface where the free ends of the staples fold upon themselves to securely attach to the tissue. Similar mechanisms may also be implemented in the embodiment as described byFIGS.1A-1D, where as the cutting element112slices through the tissue the cut ends of the tissue may be stapled simultaneously to prevent bleeding. The staples may be present on the axis parallel to the channel111such that the staples do not interfere with the movement of the cutting element112. A needle (not shown) may be disposed at the unridged portion302of this embodiment, and the end-effector101used as a needle holder for suturing. The unridged portion302may also be further used to hold the suture during a surgical maneuver. The surface may also include an adhesive coating, depressions, or slots to accommodate a needle. The surface may also be made of materials such as fabric, plastic, rubber, ceramic, or metal. The present embodiment may further be used along with the previous embodiments. The ridges109as shown in theFIGS.1-3may not be uniform in shape and dimension. For example, as shown inFIG.4, some of the ridges109may be larger than the others. The slope of the ridges109may be different for each ridge. The ridges109may have a plateau on the top surface as shown in theFIGS.1-3. Alternatively, the ridges109may have a sharp or blunt surface based on the texture and properties of the tissue to be handled. Ridges of various shapes, sizes, and orientations may coexist on the same inner surface107. The arms104may include holes402on their inner surface107, which extends to the outer surface108. The holes402form a passage through which fluids from the tissues may be squeezed out. The holes402on one arm may also line up with holes402on the opposite arm thereby a though hole may be formed. Needles, pins, fasteners or any instrument of suitable dimensions may be inserted through the holes402. In some embodiments, arms104may be hollow having a channel that is connected to a vacuum pump to assist in holding tissue. Further, the arms104may also include a locking mechanism to fix them in a specific position. Grasped tissue may be held indefinitely without application of force to the control member by locking the arms104in position. Locking means may include any suitable mechanism, such as snap fit, screw, or fastening means. The arms104may also include a magnetic element and may be locked by the magnetic attraction. In alternate embodiments, the inner surface107may be detachable. The arms104may include locking mechanisms to which the inner surface107may be attached. Alternatively, the arms104may also be detachable from the elongate member102. The outer surface108of the arms104may comprise an atraumatic surface with beveled edges as shown in the various embodiments of this disclosure. Alternatively, the outer surface108may also include abrasive elements, barbed projections, or tissue retracting arms. Additional modifications such as abrasive elements provide further tissue manipulating capabilities such as scraping removing unwanted tissue growth, plaques, and deposits. Barbed projections on the outer surface108may attach to the tissues and may be used to remove debris and sectioned tissues from narrow vessels. In some embodiments, notches may be cut into arms to assist in tissue grasping when arms104are pushed or pulled through tissue. The dimensions of the notches may vary, as desired. In addition, various alternatives of the notches may be contemplated without departing from the scope of the present disclosure. Retracting arms may prevent interference from surrounding tissue and may aid the physician in manipulating sequestered tissues. Other embodiments of the present disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the embodiments disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.

11857215

DETAILED DESCRIPTION OF EMBODIMENTS It should be mentioned at the outset that all the components of the device and the glans penis protector of this invention other than the blade which will generally be made of surgical steel and the connecting lever which will generally be made from sheet metal can, although not necessarily, be made as injection moulded plastic parts designed and made according to requirements. In the embodiment of the invention illustrated in the drawings, a circumcision device comprises two jaws (1,2) configured to crush a foreskin between them along an elongated crush region that is transverse to a foreskin (3) and transverse to a general direction in which a penis (4) (seeFIG.5) being circumcised extends. The jaws (1,2) are movable about a hinged connection at one end region (5) thereof between a first open inoperative position illustrated inFIGS.1to3and a closed operative position in which a clamping and crushing force is exerted on a foreskin positioned between the jaws (1,2) to promote hemostasis within the elongated crush region as illustrated inFIG.6. The first jaw (1) with which a cutting assembly (6) is associated is in the form of a jaw assembly composed of an arm (7) supporting a carrier (8) that has attached to it a flat surgical blade (9) (seeFIG.3). The blade (9) is guided for movement in its own plane between a guide surface (11) of the arm (7) and a parallel guide surface of an insert (12) received within the arm. A cutting edge of the blade (9), as shown inFIG.7, co-operates in the closed operative position with a crushing face (13) of the second jaw (2) within the elongated crush region such that the crushing face (13) serves as a cutting block for the blade (9). The carrier (8) has, in this embodiment of the invention, a recess accommodating an outer edge of the arm (7) with two inwardly directed lips (14) located in grooves (15) extending along the length of the arm (7) to confine movement of the carrier (8) from a first end region of the arm to a second end region of the arm. A releasable hinged stop (16) maintains the carrier in a position corresponding to the first open inoperative position of the jaws (1,2). The carrier (8) also has a catch component (17) in co-operating relationship with a complimentary co-operating catch formation (18) on the insert so that the carrier (8) becomes irreversibly locked in its terminal position at the second end region of the jaw assembly following a cutting action. This effectively prevents attempts at using the device for a subsequent circumcision, resulting in “use-once” functionality. A mechanism interconnects the jaws (1,2) such that they are movable between their first open inoperative position in which one end of a gap (21) between the jaws is open to allow for the lateral introduction of a transverse foreskin to move along the jaws to a central region thereof that is clearly indicated by suitable markers (22) and the closed operative position. The mechanism includes the hinged interconnection that is provided at a first end region (5) of the jaws (1,2) wherein the hinged connection is configured so that it cannot be disengaged when the jaws (1,2) are in their closed operative positions or second inoperative positions as described below. As regards the second ends of the jaws, they are interconnected by a lever assembly that includes an operating lever (25) pivotally attached to a connecting lever (26) at one end and pivotally connected at an opposite end to the second end of one jaw, the first jaw (1) in this instance, with the operating lever having co-axial pivot lugs (27) that are receivable in co-operating receiving formations in the form of apertures (28) associated with spaced flanges of the second jaw (2). The arrangement is such that the operating lever (25) and connecting lever (26) can be used, when the pivot lugs (27) are engaged in their co-operating apertures (28), to obstruct a lateral opening to the gap between the second ends of the two jaws (1,2) to prevent the subsequent introduction of a foreskin transversely between the jaws. The lever assembly is configured to lock the jaws (1,2) in the closed operative position in releasable manner by means of an over-centre locking mechanism as will be apparent fromFIG.6. The pivot lugs (27) are receivable in the co-operating receiving formations in the form of apertures (28) associated with the second jaw in a substantially non-releasable manner in order to obscure and deter, or render substantially impossible, a second or subsequent use of the device. By so doing, a second open inoperative position is provided in which the connecting lever and the operating lever together obscure the entrance to the gap between the jaws (1,2) in their released positions following a circumcision in a first use and substantially prevent the transverse introduction of a foreskin to a position between the jaws (1,2). Introduction of the pivot lugs is achieved in this instance by providing bevelled ends (31) (seeFIG.10) to the pivot lugs that may be forced into a space between two spaced flanges (32) of the second jaw (2). The relevant region of the operating lever (25) may be bifurcated, as indicated by numeral (33), so that the natural “give” in the plastics materials allows the pivot lugs to be urged into position between the two spaced flanges and to snap into their final positions as illustrated inFIG.10. The arrangement is such that withdrawal of the lugs is resisted so as to prevent separation of the operating lever from the second jaw. The jaws (1,2) are thus interconnected at both ends to exert a crushing force on a foreskin within the elongated crush region when the jaws are in their closed operative positions. The cutting assembly is of course movable from one end region (the first end region) of the jaws towards an opposite end region (the second end region) thereof relative to the elongated crush region so as to be capable of traversing and severing a crushed foreskin within the elongated crush region. Turning now to the second aspect of the invention, a glans penis protector for assisting in the avoidance of damage to a glans penis during a surgical circumcision procedure is particularly illustrated inFIGS.4,5and11to15and comprises a handle (41) having a proximal operating end region (42) and a transverse generally disc shaped glans penis engaging cover (43) at its distal end. The attachment of the handle (41) to the glans penis engaging cover (43) is capable of being parted so that the handle can be separated from the glans penis engaging cover during a circumcision procedure. In this embodiment of the second aspect of the invention the glans penis protector is made of injection moulded plastics material and is formed integral with the glans penis engaging cover integral with the handle. The attachment of the handle to a proximal surface (44) of the glans penis engaging cover (43) is by way of a pair of laterally spaced necks (45) located immediately adjacent the bottom of spaced in recesses (46) the proximal surface so that the necks can break off below the proximal surface (44). The glans penis engaging cover (43) is contoured in a direction transverse to the handle so as to co-operate with a distal end region of a glans penis (47) in use (seeFIG.5). The handle is generally flat with one or more apertures (48) through it and with a width of the handle being orientated such that a distal end region thereof can be accommodated in a narrow gap between two crushing jaws of a circumcision device in the first open inoperative position described above. The functionality of the protector may be enhanced by providing an axially extending probe (49) at the proximal end of the handle with the probe having a rounded end (51) for use in ensuring that the main function of the probe of the glans protector is to release adhesions safely. Normally a straight forceps that would typically be reusable is used to do this. This has the danger that it may be placed accidentally in the urethra. Adhesions are normal in infants and young children, where the foreskin has not yet been retracted. The release needs to happen before the circumcision. Steel forceps can cause penetrating injury to the glans, the mucosa, and can accidentally be inserted into the urethra which can tear. The probe has sufficient length to reach the corona at the end of the glans. The design of the glans protector and probe as a single unit, has the benefit of safely releasing the adhesions, protecting the glans and reducing the chance of accidental insertion into the urethra and still further complying with the single use requirement. A method of carrying out a circumcision of a foreskin of a patient using the circumcision device and a glans penis protector as described above thus comprises removal of any adhesions between the glans and the foreskin using the probe (49) on the back of the glans protector, and covering a glans penis of a patient with a glans penis engaging cover of a glans penis protector as described above with the handle extending generally away from the penis. The required portion of the foreskin (3) of the patient is located over the handle (41) and the foreskin (3) and handle (41) are moved transversely through an opening between corresponding ends of the jaws (1,2) of a circumcision device as described above with the glans penis engaging cover (43) immediately adjacent to the jaws (1,2) and the handle (41) passing between the jaws (1,2). The handle (41) can then be aligned with the markers (22). At that stage the handle (41) is broken away from the glans penis engaging cover (43) to leave it on the side of the jaws opposite that on which the required portion of the foreskin to be removed is located. The connecting lever (26) and operating lever (25) are moved into position to engage the pivot lugs (27) on the operating lever (25) with the co-operating receiving formations in the associated jaw. The mechanism is then operated to move the jaws (1,2) from their first open inoperative position to their closed operative position in order to crush the foreskin in an elongated crush region between the jaws (1,2) and that the crushed condition is allowed to persist for a period of time that is typically of the order of 5 minutes to promote hemostasis and a condition favourable to the severing of the foreskin by means of the cutting assembly. The releasable hinged stop (16) is then disengaged and the carrier (8) moved along the arm (7) to cause the blade (9) to sever the foreskin by co-operation with the crushing face of the other jaw. The face of the other jaw thereby acts as a cutting block for the blade. The cutting assembly is thus moved from its initial position in one end region of the arm (7) and jaws (1,2) to an opposite end region to effect severing of the foreskin crushed between the jaws (1,2). At the end of its travel along the arm (7) the carrier (8) becomes locked in its terminal position by virtue of the catch component (17) moving into co-operating relationship with the complimentary co-operating catch formation (18) on the arm so that the carrier (8) becomes irreversibly locked in its terminal position as described above. Release of the mechanism to the second open inoperative position is then carried out so that the jaws (1,2) move apart sufficiently to permit withdrawal of the attached foreskin from the circumcision device. The glans penis engaging cover can then be removed from the penis. Numerous variations to the embodiments of the two aspects of the invention described above are possible within the scope in the invention. Indeed the glans penis protector need not be used at all as the circumcision device may be used on its own. The glans penis protector may also be used on its own, and in particular in combination with existing circumcision devices where its functionality in protecting the glans penis during a cut of foreskin performed by a blade may be particularly valuable. Devices such as, for example, a Mogen clamp or Mogen clamp-type devices which include a pair of opposing jaws usable to clamp a foreskin to be severed therebetween so as to promote hemostasis as is known in the art. However, it will be appreciated that it may be used with any device or instrument that crushes a patient's foreskin, including a classical forceps guided circumcision. During use of any such device, the glans penis protector may reduce the risk of the head of the glans being crushed or cut by protecting the head and urethral opening of the penis. The gland penis protector may also be used with the Gomco clamp, Accucirc, any tissue forceps (whether serrated, toothed, flat or smooth) or the like which in use crushes the foreskin and/or mucosa of a patient and/or release adhesions prior to performing the required surgical procedure. Devices such as a Gomco clamp, Accucirc, tissue forceps or any similar or related device may also be used with the glans penis protector, where it may shield the glans penis from accidental interaction with a blade performing a cut of the foreskin. While use of the glans penis protector separately will not provide a single use circumcision device, it will provide a single-use glans penis protecting device if the handle is severed from the engaging cover as described above during use. Use of the glans penis protector together with other a known Morgen clamp-type circumcision device may therefore involve the release of adhesions to a glans penis of a patient as may be required, covering the glans penis with the glans penis engaging cover of the glans penis protector, locating a portion of the foreskin of the patient to be severed over the handle of the glans penis protector, moving the foreskin and glans penis protector transversely through an opening between corresponding ends of jaws of the Morgen clamp-type circumcision device, with the glans penis engaging cover immediately adjacent to the jaws on a proximal side thereof and the handle passing between the jaws, and parting the handle from the glans penis engaging cover to leave it on the proximal side of the jaws opposite said required portion of the foreskin to be severed. The jaws of the Morgen clamp-type circumcision device may then be closed as normal so that the foreskin of the patient is crushed therebetween. The device may further be used as normal, by for example allowing the crushed foreskin to remain in that condition for a time period selected to promote hemostasis. The foreskin may then be cut using the known method for that device, for example by a normal scalpel in a transverse direction across the foreskin. The jaws may then be opened as known to permit withdrawal of the attached foreskin from the circumcision device. The glans penis engaging cover may then be removed and discarded. It will be appreciated that the glans penis protector may be produced in a number of different sizes to accommodate a variety of glans penis sizes. This may at least partially allow for the device to be used for different age groups. In use with other circumcision devices that are not Morgen clamp-type devices, it will be apparent that the procedure will be different, as required for the specific type of device. The circumcision device provided by this invention has many features that are considered to be advantageous in that it may be configured as a single use device and does not require a long-duration on the body The device may be used to eliminate the use of separate sharp objects such as a scalpel and thereby protect patients and medical staff from risks of accidental wounds with the possibility of exposure to blood and infection. The device may be designed to be inexpensive to manufacture. Throughout the specification and claims unless the contents requires otherwise the word ‘comprise’ or variations such as ‘comprises’ or ‘comprising’ will be understood to imply the inclusion of a stated integer or group of integers.

11857216

DETAILED DESCRIPTION The present disclosure provides devices, systems, and methods facilitating removal of a large tissue specimen from an internal body cavity while maintaining the large tissue specimen in an enclosed environment during break down and removal from the internal body cavity. Turning initially toFIGS.1A and1B, a specimen retrieval system101provided in accordance with the present disclosure generally includes an outer assembly, such as, for example, an access cannula100, an inner assembly, such as, for example, a deployment cannula200, and a containment bag300. Access cannula100includes a proximal hub110, an elongated tubular member120, and an open distal mouth130. A lumen140extends through proximal hub110and elongated tubular member120, in communication with open distal mouth130, to enable the insertion of deployment cannula200, and, in some embodiments, other surgical instruments, through access cannula100and into a cavity “C” of containment bag300via an open end portion310of containment bag300. Proximal hub110of access cannula100is configured to remain externally-disposed and may include an insufflation port107to enable the introduction of insufflation fluid through lumen140and into the internal body cavity to insufflate the internal body cavity. To this end, proximal hub110may further include one or more seals (not shown) configured to seal lumen140in the absence of deployment cannula200, containment bag300, and/or other surgical instruments inserted therethrough, and/or to establish a seal about deployment cannula200, containment bag300, and/or other surgical instruments inserted through lumen140, in order to maintain the internal body cavity in an insufflated condition. Elongated tubular member120of access cannula100is configured to extend through a surgically created or naturally occurring opening “O” into an internal body cavity “BC” such that open distal mouth130is at least partially disposed within internal body cavity “BC,” while proximal hub110remains externally disposed. Open distal mouth130of access cannula100is configured to facilitate atraumatic insertion of elongated tubular member120through the surgically created or naturally occurring opening “O” and into the internal body cavity. In embodiments, open distal mouth130of access cannula100may include a beveled or other suitable configuration. Continuing with reference toFIGS.1A and1B, deployment cannula200includes a proximal hub210, an elongated core, such as, for example, a tubular member220, an open distal mouth230, and a port guard assembly240. A lumen260extends through proximal hub210and elongated tubular member220, in communication with open distal mouth230, to enable the insertion of surgical instruments through deployment cannula200and into cavity “C” of containment bag300via open end portion310of containment bag300. Deployment cannula200is configured for slidable positioning within lumen140of access cannula100and may be positioned therein in an initial condition (FIG.1A) during manufacturing or may be inserted into access cannula100by a user. Proximal hub210of deployment cannula200is configured to remain externally-disposed relative to the internal surgical site and access cannula100. More specifically, in an initial condition (FIG.1A) of specimen retrieval system101, proximal hub210of deployment cannula200is positioned proximally adjacent proximal hub110of access cannula100. In a deployed condition (FIG.1B), on the other hand, proximal hub210of deployment cannula200is proximally-spaced from proximal hub110of access cannula100, although it is also contemplated that this configuration be reversed. It is further contemplated that at least a portion of tubular member220is retained within lumen140of access cannula100when specimen retrieval system101is moved between the initial and deployed conditions. Similarly, as with proximal hub110of access cannula100, proximal hub210of deployment cannula200may include one or more seals (not shown) configured to seal lumen260in the absence of surgical instruments inserted therethrough and/or to establish a seal about surgical instruments inserted through lumen260, in order to maintain the internal body cavity in an insufflated condition. Proximal hub210of deployment cannula200may also include an insufflation port (not shown) to enable the introduction of insufflation fluid through lumen260to, for example, insufflate containment bag300. Tubular member220of deployment cannula200is configured to extend through lumen140of access cannula100and into cavity “C” of containment bag300. More specifically, tubular member220defines a suitable length so as to enable proximal hub210of deployment cannula200to remain externally disposed of the internal body cavity and access cannula100while a distal end of elongated tubular member220extends to or beyond open distal mouth130of access cannula100. Port guard assembly240includes a plurality of engagement arms242having a first arm portion242ahingedly coupled to a second arm portion242b. Further, a proximal end portion of first arm portion242ais hingedly coupled to an exterior surface of tubular member220and a distal end portion of second arm portion242bis hingedly coupled to a cuff244that is coupled to the exterior surface of tubular member220, proximally adjacent open distal mouth230thereof. The plurality of engagement arms242may be radially-spaced about a circumference of cuff244, although any suitably configuration for the plurality of engagement arms242may be provided. The various hinge couplings detailed above may include living hinges, pivot-pin hinges, or other suitable hinge arrangements to enable the plurality of engagement arms242to transition between a contracted configuration and an expanded configuration. Specifically, in the initial condition (FIG.1A) of specimen retrieval system101, wherein tubular member220of deployment cannula200is disposed within lumen140of access cannula100and proximal hub210of deployment cannula200is positioned proximally adjacent proximal hub110of access cannula100, engagement arms242are retained in the contracted configuration, wherein engagement arms242extend alongside the exterior of tubular member220to define a generally linear configuration, thus enabling engagement arms242and tubular member220to fit within lumen140of access cannula100. Once deployment cannula200is moved proximally relative to access cannula100towards the deployed condition (FIG.1B) of specimen retrieval system101, the proximal end portions of first arm portions242aof the engagement arms242are pushed against open distal mouth130of access cannula100and the distal end portions of the second arm portions242bof the engagement arms242are moved towards the proximal end portions of first arm portions242asuch that, engagement arms242, lead by the hinges coupling the respective first and second arm portions242a,242bthereof, flex or expand outward from the exterior surface of tubular member220to the expanded configuration. In embodiments, in the deployed condition (FIG.1B) of specimen retrieval system101and, thus, the expanded configuration of engagement arms242, engagement arms242may be positioned to define a basket-like configuration. In the deployed condition, port guard assembly240is configured to engage and provide structural support to containment bag300to maintain containment bag300spaced-apart from distal mouth230of deployment cannula200, as detailed below. It is contemplated that engagement arms242may be biased radially-outwardly from elongated tubular member220towards the expanded configuration of engagement arms242such that, in the initial condition of specimen retrieval system101(FIG.1A), engagement arms242are retained, against their bias, in the contracted configuration. In embodiments, engagement arms242may be formed from a spring-metal, e.g., spring steel, although other suitable materials, e.g., nitinol, are also contemplated. Further, as an alternative to providing deployment cannula200with engagement arms242, engagement arms242may be disposed on another surgical instrument to be used within the internal body cavity such as, for example, a morcellator (not shown). An exemplary morcellator for this purpose is described in Patent Application Publication No. US 2015/0073429, filed on Jun. 12, 2014, the entire contents of which are hereby incorporated herein by reference. With continued reference toFIGS.1A and1B, containment bag300includes an outer surface320a, an inner surface320b, and cavity “C” defined by inner surface320band configured to enable positioning of a tissue specimen(s) therein. Further, as described above, containment bag300includes open end portion310configured to receive at least a portion of access cannula100and deployment cannula200within cavity “C” of containment bag300. In the initial condition (FIG.1A) of specimen retrieval system101, with containment bag300deployed about access cannula100and deployment cannula200, a top portion330of containment bag300disposed towards open end portion310, may be positioned substantially adjacent open distal mouths130,230of access cannula100and deployment cannula200, respectively, in contact therewith or to define a first annular space “A1” therebetween. In the deployed condition (FIG.1B) of specimen retrieval system101, with containment bag300deployed about access cannula100and deployment cannula200, engagement arms242of port guard assembly240expand outward from the exterior surface of tubular member220and are configured to engage inner surface320bof containment bag300adjacent top portion330of containment bag300and to urge top portion330of containment bag300radially outwardly relative to access cannula100and deployment cannula200. As such, the engagement arms242ensure that top portion330of containment bag300is maintained radially spaced-apart from open distal mouths130,230of access cannula100and deployment cannula200, respectively, to define a minimum second annular space “A2” therebetween that is greater than first annular space “A1.” In the deployed condition (FIG.1B) of specimen retrieval system101, port guard assembly240is configured to prevent top portion330of containment bag300from collapsing about open distal mouths130,230of access cannula100and deployment cannula200, respectively, as detailed above. More specifically, port guard assembly240is configured to serve as a spacer between top portion330of containment bag300and open distal mouths130,230of access cannula100and deployment cannula200, respectively, such that, one or more surgical instrument(s)2(FIG.2B) inserted through deployment cannula200and access cannula100, and into cavity “C” of containment bag300, are inhibited from contacting inner surface320badjacent the top portion330of containment bag300. In embodiments, surgical instrument2may be a morcellator or another cutting device. In such embodiments, port guard assembly240is configured to inhibit contact between the morcellator or the another cutting device and inner surface320badjacent the top portion330of containment bag300to inhibit cutting or tearing of containment bag300. Containment bag300may define any suitable configuration such as, for example, a circular, dogleg, L-shape, C-shape, or other suitable configuration. The particular configuration of containment bag300may depend upon the desired access location and/or the procedure to be performed. Containment bag300may be formed from any suitable material. In particular, containment bag300may be formed from a transparent, tear-resistant, stretchable material to enable visualization into containment bag300from the exterior thereof, inhibit tearing, and facilitate manipulation of containment bag300, tissue specimen(s), and/or surgical instruments2during use. Open end portion310of containment bag300may include features (not shown) to facilitate sealed closure thereof such as, for example, a threaded lip configured to receive a screw-on cap, or may be configured to be sealed closed by way of a suture, clip, cord, or other suitable mechanism or method. Open end portion310may be configured to receive a tissue specimen therethrough and into cavity “C” of containment bag300. Alternatively or additionally, containment bag300may include one or more other openings (not explicitly shown) in addition to open end portion310to facilitate insertion of a tissue specimen therethrough and into cavity “C” of containment bag300. These other openings may likewise include features similar to those of open end portion310to facilitate sealed closure thereof. With reference toFIGS.2A and2B, in conjunction withFIGS.1A and1B, the use of specimen retrieval system101in the removal of a tissue specimen “S” from internal body cavity “BC” is described. Specimen retrieval system101may be similarly used in the removal of other tissue specimen from other internal body cavities. Referring first toFIG.2A, with deployment cannula200disposed within access cannula100and proximal hub210of deployment cannula200positioned proximally adjacent proximal hub110of access cannula100such that engagement arms242are retained in the contracted configuration (FIG.1A), access cannula100and deployment cannula200are advanced through surgically created or naturally occurring opening “O” into internal body cavity “BC.” Access cannula100and deployment cannula200may be inserted directly or may be inserted through a port (not shown). Additionally or alternatively, insertion of access cannula100and deployment cannula200may be facilitated through the use of a trocar (not shown) disposed within or about access cannula100or deployment cannula200. Continuing withFIG.2A, Containment bag300may be inserted into internal body cavity “BC” via a port4, and may be deployed about elongated tubular member120of access cannula100and tubular member220of deployment cannula200using a suitable deployment apparatus6. Alternatively, containment bag300and deployment apparatus6may be operably disposed about elongated tubular member120of access cannula100towards open distal mouth130thereof, or may be coupled to an outer deployment tube (not shown) disposed about elongated tubular member120, to enable containment bag300to be deployed distally from elongated tubular member120about open distal mouth130. Once deployed into or otherwise disposed within the internal body cavity “BC,” containment bag300and/or the tissue specimen “S” are manipulated, e.g., using a grasper (not shown) inserted through deployment cannula200or another port (not shown), to position the tissue specimen “S” within cavity “C” of containment bag300. Thereafter or prior thereto, if not already so positioned (such as, for example, in embodiments where containment bag300is deployed from access cannula100), open end portion310(FIG.1A) of containment bag300is positioned to surround open distal mouths130,230of access cannula100and deployment cannula200, respectively. Open end portion310of containment bag300may then be cinched or otherwise secured about open distal mouth130of access cannula100to form a substantially fluid-tight seal, thereby sealing open distal mouths130,230of access cannula100and deployment cannula200, respectively, within cavity “C” of containment bag300. To this end, an annular divot106may be defined within the exterior surface of elongated tubular member120of access cannula100towards open distal mouth130thereof to facilitate cinching the open end portion310of containment bag300about elongated tubular member120of access cannula100and to “lock” the open end portion310of containment bag300in position about elongated tubular member120. In embodiments, containment bag300may be positioned within internal body cavity “BC” prior to advancing access cannula100and deployment cannula200into internal body cavity “BC.” Specifically, once containment bag300is disposed within internal body cavity “BC” and tissue specimen “S” is positioned within cavity “C” of containment bag300, open end portion310of containment bag300may be exteriorized from internal body cavity “BC” through opening “O.” Next, open distal mouths130,230of access cannula100and deployment cannula200, respectively, may be advanced through opening “O” and open end portion310of containment bag300and into within cavity “C” of containment bag300. Finally, open end portion310of containment bag300may be cinched or otherwise secured about open distal mouth130of access cannula100in the manner described above, or may remain open, externally of the body cavity “BC.” Turning toFIG.2B, with containment bag300sealed about open distal mouth130of elongated tubular member120of access cannula100, or externalized from the body cavity “BC,” such that open distal mouths130,230of access cannula100and deployment cannula200, respectively, are disposed within cavity “C” of containment bag300, deployment cannula200may be moved proximally relative to access cannula100towards the deployed condition (FIG.1B) of specimen retrieval system101such that, engagement arms242of port guard assembly240expand outward from the exterior surface of tubular member220and engage inner surface320badjacent top portion330of containment bag300, urging top portion330of containment bag300radially outwardly to maintain top portion330of containment bag300spaced-apart from open distal mouths130,230. Once specimen retrieval system101is in the deployed condition, surgical instrument2may be inserted through deployment cannula200(and, thus, through access cannula100) such that surgical instrument2extends from open distal mouth230of deployment cannula200and is disposed adjacent tissue specimen “S.” Surgical instrument2may then be used to morcellate or otherwise act on the tissue specimen “S,” for example, to break down the tissue specimen “S” into smaller pieces to facilitate removal. In embodiments, surgical instrument2may include any suitable dimension (e.g., diameter) configured for a particular purpose, for example, to maximize the resection rate of tissue specimen “S.” As detailed above, damage to containment bag300from contact with surgical instrument2during insertion, breakdown of the tissue specimen “S,” and removal, is inhibited by virtue of engagement arms242of port guard assembly240maintaining top portion330of containment bag300spaced-apart from open distal mouths130,230. Surgical instrument2may also include one or more feature(s) configured to control the extension of a distal end thereof beyond open distal mouth230of deployment cannula200. It is contemplated that limiting the extension of the distal end of surgical instrument2to a position, for example, where a cutting edge of surgical instrument2is disposed just below port guard assembly240would ensure that surgical instrument2is not advanced too far into containment bag300, thereby inhibiting surgical instrument2from inadvertently cutting or tearing containment bag300opposite top portion330thereof. In order to position tissue specimen “S” adjacent surgical instrument2, a user may utilize a tenaculum (not shown) or the like, to move tissue specimen “S” towards surgical instrument2. Continuing withFIG.2B, a visualization device8may be utilized to facilitate breakdown of the tissue specimen “S.” Visualization device8may include a laparoscope or the like, and have any suitable dimension (e.g., 5 mm diameter laparoscope). In embodiments, visualization device8may be inserted through deployment cannula200(and, thus, through access cannula100) via a lumen (not shown) separate from lumen260used for the insertion of surgical instrument2. Alternatively, visualization device8may be inserted through access cannula100via a lumen (not shown) separate from lumen140used for the insertion of deployment cannula200. Visualization device8may also be disposed within internal body cavity “BC” via a secondary port (not shown) and disposed within containment bag300via a secondary opening (not shown). In embodiments where containment bag300is formed from a transparent material, visualization device8may be disposed within internal body cavity “BC” and remain external of containment bag300while providing a view of cavity “C” of containment bag300. Visualization device8may include an articulating scope (not shown) configured to facilitate maneuverability as well as visibility within body cavity “BC” and cavity “C” of containment bag300. Once the tissue specimen “S” is sufficiently broken down, surgical instrument2and visualization device8may be removed from cavity “C” of containment bag300and from internal body cavity “BC”. Thereafter, access cannula100and deployment cannula200are returned (fully or partially) towards the initial condition (FIG.1A) of specimen retrieval system101, wherein engagement arms242are in the contracted configuration alongside the exterior of tubular member220of deployment cannula200. Further, containment bag300may be released from its deployment apparatus6to enable withdrawal of access cannula100together with containment bag300from internal body cavity “BC.” Alternatively, in embodiments where containment bag300is removable from elongated tubular member210of access cannula100, containment bag300may be released therefrom after engagement arms242are contracted such that access cannula100and deployment cannula200may be removed through the opening “O” while containment bag300may be removed through port4. Turning now toFIGS.3and4, a specimen retrieval system102provided in accordance with another aspect of the present disclosure generally includes an inner assembly, such as, for example, an access cannula400, an outer assembly, such as, for example, an introducer500, and a containment bag600. With reference toFIG.3, introducer500generally includes a proximal hub510, an elongated tubular member520, and a lumen530extending through proximal hub510and elongated tubular member520. Lumen530of introducer500defines a suitable diameter configured to enable positioning of access cannula400and containment bag600therein. In embodiments, introducer500is provided with a first introducer portion540aand a second introducer portion540bthat may be selectively coupled to form introducer500and selectively decoupled to form discrete first and second introducer portions540a,540b. It is contemplated that first and second introducer portions540a,540bmay be releasably coupled via snap-fit or other suitable engagement(s). In an initial condition (FIG.3) of specimen retrieval system102, with access cannula400and containment bag600disposed within lumen530of introducer500, elongated tubular member520of introducer500is configured to extend through surgically created or naturally occurring opening “O” into the internal body cavity “BC” such that at least a portion of elongated tubular member520, with access cannula400and containment bag600disposed therein, is positioned within internal body cavity “BC.” As detailed below, once access cannula400and containment bag600are sufficiently disposed within internal body cavity “BC,” introducer500may be disassembled into discrete first and second introducer portions540a,540band removed from within internal body cavity “BC” and about access cannula400to transition specimen retrieval system102towards a deployed condition (FIG.4). Access cannula400may be similar to and/or include any of the features of access cannula100(FIGS.1A and1B), detailed above. Access cannula400generally includes a proximal hub410, an elongated tubular member420, an open distal mouth430, and a port guard assembly440. A lumen460extends through proximal hub410and elongated tubular member420, in communication with open distal mouth430. With reference toFIG.4, port guard assembly440includes a plurality of engagement fingers442configured as cantilever springs. Engagement fingers442are arranged radially-spaced about elongated tubular member420of access cannula400and extend distally therefrom. More specifically, engagement fingers442each include a fixed end442aand a free end442b. Fixed ends442aof engagement fingers442are fixed to the exterior surface of elongated tubular member420adjacent open distal mouth430and extend distally to free ends442bthereof. Free ends442bof engagement fingers442extend distally beyond open distal mouth430of elongated tubular member420and are biased radially-outwardly from elongated tubular member420. It is contemplated that any suitable number of engagement fingers442may be provided. Engagement fingers442may be formed from a spring-metal, e.g., spring steel, although other suitable materials, e.g., nitinol, may also be used. In the initial condition (FIG.3) of specimen retrieval system102, wherein elongated tubular member420of access cannula400is disposed within lumen530of introducer500, introducer400retains engagement fingers442, against their bias, in a contracted configuration, wherein free ends442bof engagement fingers442extend alongside one another, thus enabling engagement fingers442and elongated tubular member420to fit within lumen530of introducer500. In the deployed condition (FIG.4) of specimen retrieval system102, introducer500is disassembled into discrete first and second introducer portions540a,540band removed from about elongated tubular member420, thus enabling engagement fingers442to return under bias towards their at-rest position, wherein free ends442bof engagement fingers442are radially-outwardly spaced from elongated tubular member420to define an umbrella-like configuration. In embodiments, it is contemplated that port guard assembly440may be a stand-alone device, separate from access cannula400, or may be connectable to access cannula400for use therewith or therewithout. In embodiments, port guard assembly440may be inserted through access cannula440until engagement fingers442extend distally from open distal mouth430to define the umbrella-like configuration described above. Referring toFIGS.3and4, containment bag600may be similar to and/or include any of the features of containment bag300(FIGS.1A and1B), detailed above. Containment bag600generally includes an outer surface620a, an inner surface620b, and a cavity “C” defined by inner surface620band configured to enable positioning of a tissue specimen(s) therein. Further, containment bag600includes an open end portion610configured to receive at least a portion of access cannula400and port guard assembly440thereof within cavity “C” of containment bag600. Containment bag600is configured for positioning, in the initial condition (FIG.3) of specimen retrieval system102, in the annular space defined between elongated tubular member520of introducer500and elongated tubular member420of access cannula400, although a portion of containment bag600may extend proximally from both introducer500and access cannula400in the initial condition of specimen retrieval system102. In the deployed condition (FIG.4) of specimen retrieval system102, containment bag600is deployed into the internal body cavity “BC” under urging from engagement fingers442of access cannula400and is unfurled, thus presenting containment bag600to enable positioning of tissue specimen(s) similar to tissue specimen “S” (FIGS.2A and2B) therein. Containment bag600may alternatively be separately positioned within the internal body cavity “BC” and thereafter engaged with access cannula400. In the deployed condition (FIG.4) of specimen retrieval system102, similar to port guard assembly240(FIG.2), engagement fingers442of port guard assembly440of access cannula400are configured to engage a top portion630of containment bag600, adjacent open end portion610, and to urge top portion630of containment bag600radially outwardly to inhibit top portion630of containment bag600from collapsing about open distal mouth430of access cannula400. As such, port guard assembly440is similarly configured to serve as a spacer between top portion630of containment bag600and open distal mouth430of access cannula400such that, a surgical instrument similar to surgical instrument2(FIG.2B) e.g., morcellator or another cutting device, inserted through access cannula400, and into cavity “C” of containment bag600, is inhibited from inadvertently cutting or tearing containment bag600. In addition to serving as a spacer, engagement fingers442also serve as guards to deflect surgical instrument2(FIG.2B) should surgical instrument2stray towards inhibited top portion630of containment bag600. Containment, breakdown, and removal of the tissue specimen “S” (FIG.2B) using containment bag600may be accomplished similarly as detailed above with regard to specimen retrieval system101(FIGS.2A and2B). Further, similarly as detailed above with regard to specimen retrieval system101(FIGS.2A and2B), some or all of the above may be performed under observation using visualization device8(FIG.2B). Turning now toFIGS.5and6, a specimen retrieval system103provided in accordance with another aspect of the present disclosure generally includes an access cannula700and a containment bag800. Access cannula700may be similar to and/or include any of the features of access cannulas100,400(FIGS.1A-4), detailed above. Access cannula700generally includes a proximal hub710, an elongated tubular member720, an open distal mouth730, and a port guard assembly740. A lumen760extends through proximal hub710and elongated tubular member720, in communication with open distal mouth730. Port guard assembly740includes an inflatable member, such as, for example, a balloon742fixed to the exterior surface of elongated tubular member720adjacent open distal mouth730. More specifically, balloon742defines a donut-shaped configuration defining a lumen744configured to receive a portion of elongated tubular member720adjacent open distal mouth730. Elongated tubular member720may be fixed within lumen744of balloon742using an adhesive or other suitable methods. In embodiments, an interior cavity746of balloon742is in fluid communication with lumen760of elongated tubular member720via lumen744such that balloon742is selectively inflatable. Accordingly, balloon742may be transitioned between a deflated configuration when specimen retrieval system103is in an initial condition (FIG.5) and an inflated configuration when specimen retrieval system103is in a deployed condition (FIG.6). Containment bag800may be similar to and/or include any of the features of containment bags300,600(FIGS.1A-4), detailed above. Containment bag800generally includes an outer surface820a, an inner surface820b, and a cavity “C” defined by inner surface820band configured to enable positioning of tissue specimen(s) similar to tissue specimen “S” (FIGS.2A and2B) therein. Further, containment bag800includes an open end portion810configured to receive at least a portion of access cannula700and port guard assembly740thereof within cavity “C” of containment bag800. In the deployed condition (FIG.6) of specimen retrieval system103, similar to port guard assemblies240,440(FIGS.1B and4), balloon742of port guard assembly740is configured to urge a top portion830of containment bag800radially outwardly, thus inhibiting top portion830from collapsing about open distal mouth730of access cannula700. More specifically, as balloon742is inflated towards the deployed condition (FIG.6), balloon742is configured to engage inner surface820badjacent top portion830and urge top portion830radially outwardly to increase the annular space between open distal mouth730of access cannula700and top portion830of containment bag800. As such, port guard assembly740is similarly configured to act as a spacer between top portion830of containment bag800and open distal mouth730of access cannula700such that a surgical instrument similar to surgical instrument2(FIG.2B) e.g., morcellator or another cutting device, inserted through access cannula700, and into cavity “C” of containment bag800, is inhibited from cutting or tearing containment bag800. In embodiments, specimen retrieval system103may include an introducer (not shown) similar to introducer500(FIG.3) to facilitate insertion of access cannula700and containment bag800into internal body cavity “BC” via surgically created or naturally occurring opening “O” in the initial condition (FIG.5) of specimen retrieval system103. Once the tissue specimen “S” (FIG.2B) is sufficiently broken down and removed from containment bag800, balloon724may be deflated (fully or partially) to return specimen retrieval system103towards the initial condition (FIG.5), wherein top portion830of containment bag800is contracted about open distal mouth730of access cannula700. Thereafter, access cannula700and containment bag800may be withdrawn together, or separately, from within internal body cavity “BC.” In embodiments, containment, breakdown, and removal of the tissue specimen “S” (FIG.2B) using containment bag800may be accomplished similarly as detailed above with regard to specimen retrieval system101(FIGS.2A and2B). Further, similarly as detailed above with regard to specimen retrieval system101(FIGS.2A and2B), some or all of the above may be performed under observation using visualization device8(FIG.2B). Turning now toFIGS.7and8, a specimen retrieval system104provided in accordance with another aspect of the present disclosure generally includes an access cannula900and a containment bag1000. Access cannula900may be similar to and/or include any of the features of access cannulas100,400,700(FIGS.1A-6), detailed above. Access cannula900generally includes a proximal hub910, an elongated tubular member920, an open distal mouth930, and a port guard assembly940. A lumen960extends through proximal hub910and elongated tubular member920, in communication with open distal mouth930. Port guard assembly940may be similar to and/or include any of the features of port guard assemblies440,740(FIGS.4and6), as detailed above. Port guard assembly940generally includes a plurality of engagement fingers942and an inflatable member, such as, for example, a balloon944. Engagement fingers942each include a fixed end942a, hingedly coupled to the exterior surface of elongated tubular member920, and extending distally to a free end942b. Balloon944defines a donut-shaped configuration and includes a lumen946configured to fixedly receive a portion of elongated tubular member920. Similar to balloon742, balloon944is configured to be manipulated between a deflated configuration when specimen retrieval system104is in an initial condition (FIG.7) and an inflated configuration when specimen retrieval system104is in the deployed condition (FIG.8). Balloon944is disposed about elongated tubular member920at a position distal to fixed ends942aof engagement fingers942such that engagement fingers942extend distally along the exterior surface of balloon944to free ends942b. In the initial condition (FIG.7) of specimen retrieval system104, balloon944is deflated and free ends942bof engagement fingers942extend alongside one another over the exterior surface of balloon944. In the deployed condition (FIG.8) of specimen retrieval system104, balloon944is inflated and engages the engagement fingers942disposed on the exterior surface thereof. As such, engagement fingers942are urged radially-outwardly from elongated tubular member920with the expansion of balloon944. Containment bag1000may be similar to and/or include any of the features of containment bags300,600,800(FIGS.1A-6), detailed above. Containment bag1000generally includes an outer surface1020a, an inner surface1020b, and a cavity “C” defined by inner surface1020band configured to enable positioning of tissue specimen(s) similar to tissue specimen “S” (FIGS.2A and2B) therein. Further, containment bag1000includes an open end portion1010configured to receive at least a portion of access cannula900and port guard assembly940thereof within cavity “C” of containment bag1000. In the deployed condition (FIG.8) of specimen retrieval system104, similar to port guard assemblies240,440,740(FIGS.2,4, and6), port guard assembly940is configured to prevent a top portion1030of containment bag1000, towards open end portion1010, from collapsing about open distal mouth930of access cannula900. More specifically, as balloon944is inflated towards the deployed condition (FIG.8), balloon944urges engagement fingers942radially outwardly from elongated tubular member920such that, engagement fingers942engage inner surface1020badjacent top portion1030to urge top portion1030radially outwardly, thereby increasing the annular space between open distal mouth930of access cannula900and top portion1030of containment bag1000. As such, port guard assembly940is similarly configured to provide a spacer between top portion1030of containment bag1000and open distal mouth930of access cannula900such that, a surgical instrument similar to surgical instrument2(FIG.2B) e.g., morcellator or another cutting device, inserted through access cannula900, and into cavity “C” of containment bag1000, is inhibited from cutting or tearing containment bag1000. In embodiments, specimen retrieval system104may include an introducer (not shown) similar to introducer500(FIG.3) such that access cannula900and containment bag1000may be disposed within internal body cavity “BC” via surgically created or naturally occurring opening “O” in the initial condition (FIG.7) of specimen retrieval system104. Once the tissue specimen “S” (FIG.2B) is sufficiently broken down and removed from containment bag1000, balloon944may be deflated (fully or partially) to return specimen retrieval system104towards the initial condition (FIG.7), wherein engagement fingers942are in the contracted configuration and extend alongside one another over the exterior surface of balloon944and top portion1030of containment bag1000is contracted about open distal mouth930of access cannula900. Thereafter, access cannula900and containment bag1000may be withdrawn together, or separately, from within internal body cavity “BC.” In embodiments, containment, breakdown, and removal of the tissue specimen “S” (FIG.2B) using containment bag1000may be accomplished similarly as detailed above with regard to specimen retrieval system101(FIGS.2A and2B). Further, similarly as detailed above with regard to specimen retrieval system101(FIGS.2A and2B), some or all of the above may be performed under observation using visualization device8(FIG.2B). Turning now toFIGS.9-12, a specimen retrieval system105provided in accordance with another aspect of the present disclosure generally includes an outer assembly, such as, for example, an access cannula2000, an inner assembly, such as, for example, a deployment cannula3000, and a containment bag4000. Access cannula2000may be similar to and/or include any of the features of access cannulas100,400,700,900(FIGS.1-8), detailed above. Access cannula2000generally includes a proximal hub2010, an elongated tubular member2020, an open distal mouth2030, and a port guard assembly2040. A lumen2060extends through proximal hub2010and elongated tubular member2020, in communication with open distal mouth2030. Deployment cannula3000may be similar to and/or include any of the features of deployment cannula200(FIGS.1A and1B), detailed above. Deployment cannula3000generally includes a proximal hub3010, an elongated core, such as, for example, a tubular member3020, an open distal mouth3030, and a camming boss3040. In embodiments, camming boss3040is configured as a plurality of radially spaced-apart protrusions or tabs disposed on the exterior surface of tubular member3020towards open distal mouth3030. A lumen3060extends through proximal hub3010and tubular member3020, in communication with open distal mouth3030. Deployment cannula3000is configured for slidable positioning within lumen2060of access cannula2000and may be positioned therein in an initial condition (FIG.9) during manufacturing or may be inserted into access cannula2000by a user. Proximal hub3010of deployment cannula3000is configured to remain externally-disposed relative to the internal surgical site and access cannula2000. More specifically, in an initial condition (FIG.9) of specimen retrieval system105, proximal hub3010of deployment cannula3000is positioned proximally adjacent proximal hub2010of access cannula2000. In a deployed condition (FIG.10), on the other hand, proximal hub3010of deployment cannula3000is proximally-spaced from proximal hub2010of access cannula2000. With reference toFIGS.11and12, port guard assembly2040includes a plurality of petals2042that are folded to overlap with adjacent petals2042. Petals2042each include a fixed end2042a, having a living hinge (or other suitable hinge structure) coupled to the exterior surface of elongated tubular member2020adjacent open distal mouth2030(FIGS.9and10), and extending distally to a free end2042b. In the initial condition (FIG.9) of specimen retrieval system105, petals2042are retained in a contracted configuration, wherein petals2042extend alongside the exterior of tubular member3020of deployment cannula3000(FIG.11). In embodiments, in the initial condition (FIG.9) of specimen retrieval system105, petals2042are arranged to include a base layer of petals2044(FIG.11) disposed adjacent the exterior of tubular member3020and a top layer of petals2046(FIG.11) folded over and disposed adjacent the base layer of petals2044in offset orientation relative to the base layer. As deployment cannula3000is moved proximally relative to access cannula2000towards the deployed condition (FIG.10) of specimen retrieval system105, camming boss3040cams proximally along the interior surface of the base layer of petals2044of petals2042towards fixed ends2042athereof. The movement of camming boss3040increasingly urges the base layer of petals2044radially outwardly such that the overlapping top layer of petals2046are likewise increasing urged radially outwardly. As such, petals2042expand outward from the exterior surface of tubular member3020and are radially-outwardly spaced from elongated tubular member2020of access cannula2000(FIG.12). With reference again toFIGS.9and10, containment bag4000may be similar to and/or include any of the features of containment bags300,600,800,1000(FIGS.1-8), detailed above. Containment bag4000generally includes an outer surface4020a, an inner surface4020b, and a cavity “C” defined by inner surface4020band configured to enable positioning of tissue specimen(s) similar to tissue specimen “S” (FIGS.2A and2B) therein. Further, containment bag4000includes an open end portion4010configured to receive at least a portion of access cannula2000, port guard assembly2040thereof, and deployment cannula3000within cavity “C” of containment bag4000. In the deployed condition (FIG.10) of specimen retrieval system105, similar to port guard assemblies240,440,740,940(FIGS.1B,4,6, and8), port guard assembly2040is configured to urge a top portion4030of containment bag4000radially outwardly, thus inhibiting top portion4030of containment bag4000from collapsing about open distal mouth2030of access cannula2000. More specifically, as petals2042are expanded towards the deployed condition (FIG.10), petals2042engage inner surface4020badjacent top portion4030and urge top portion4030radially outwardly to increase the annular space between open distal mouth2030of access cannula2000and top portion4030of containment bag4000. As such, port guard assembly2040is similarly configured to provide a spacer between top portion4030of containment bag4000and open distal mouth2030of access cannula2000such that, a surgical instrument similar to surgical instrument2(FIG.2B) e.g., morcellator or another cutting device, inserted through deployment cannula3000and, and into cavity “C” of containment bag4000, is inhibited from cutting or tearing containment bag4000. In embodiments, specimen retrieval system105may include an introducer (not shown) similar to introducer500(FIG.3) such that access cannula2000, deployment cannula300, and containment bag4000may be disposed within internal body cavity “BC” via surgically created or naturally occurring opening “O” in the initial condition (FIG.9) of specimen retrieval system105. Containment, breakdown, and removal of the tissue specimen “S” (FIG.2B) using containment bag4000may be accomplished similarly as detailed above with regard to specimen retrieval system101(FIGS.2A and2B). Further, similarly as detailed above with regard to specimen retrieval system101(FIGS.2A and2B), some or all of the above may be performed under observation using visualization device8(FIG.2B). From the foregoing and with reference to the various drawings, those skilled in the art will appreciate that certain modifications can be made to the present disclosure without departing from the scope of the same. While several embodiments of the disclosure have been shown in the drawings, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

11857217

DETAILED DESCRIPTION The present disclosure relates generally to cannulas for surgical procedures. More specifically, the present disclosure provides a nested cannula system in which each cannula in the system may be used individually with a handle, or may be interlocked with any other cannula in the system. When two cannulas are interlocked with one another, one cannula is nested within a second cannula. The handle is a separate handle component of the provided cannula system that may be used with each cannula individually. In this way, the presently disclosed nested cannula system enables a surgeon to use the smallest cannula that is needed for a given procedure, which results in smaller incisions or bone holes and faster patient recovery times. The presently disclosed nested cannula system additionally enables a surgeon to skip unneeded cannula sizes when switching from one size to another since each cannula may be used with any other cannula by way of respective locking mechanisms on each cannula. In this way, the provided cannula system can help place less stress on a patient's soft tissue, bone, joint, etc. by eliminating the need to use all intermediate cannulas as compared to typical nested cannula systems. The respective locking mechanisms of the provided cannulas interlock two nested cannulas with one another. In at least some aspects, the respective locking mechanisms maintain concentricity between two nested cannulas. In some aspects, a respective locking mechanism may prevent rotation between two nested cannulas with respect to one another. In some aspects, the respective locking mechanisms may be constructed to enable an ordered release of nested and interlocked cannulas such that, for example, it is easier (e.g., requires less force) to disengage and remove a first cannula from a second cannula than it is to disengage and remove the second cannula from a third cannula. The ordered release can help a surgeon disengage and remove the first cannula without disengaging or removing the second and third cannulas, and in at least some instances, can help the surgeon do this with one hand to free up the surgeon's other hand during surgery. FIG.1illustrates an example cannula system100, according to an aspect of the present disclosure. In some aspects, the example cannula system100includes a handle120and three differently-sized cannulas110A,110B, and110C. In other aspects, the cannula system100may include more than three differently-sized cannulas110A,110B,110C. The cannula110A includes a head116A, and tube112A with a diameter114A. The cannula110B similarly includes a head116B, and a tube112B with a diameter114B. The cannula110C similarly includes a head116C, and a tube112C with a diameter114C. The cannulas110A,110B, and110C are sized in a sequence of smaller cannulas to larger cannulas. For instance, the cannula110C is larger than the cannula110B, which is larger than the cannula110A. For example, the diameter114C of the tube112C is larger than the diameter114B of the tube112B, which is larger than the diameter114A of the tube112A. In aspects in which the cannula system100includes more than three cannulas110A,110B,110C, the sequence may further include a cannula larger than the cannula110C or a cannula smaller than the cannula110A, and so forth. In some aspects of the present disclosure, it may be only the respective tubes112A,112B, and112C of each cannula110A,110B,110C in the cannula system100that change in size. Stated differently, in such aspects only the diameters114A,114B, and114C of the respective tubes112A,112B, and112C change in size among the sequence of cannulas while the size of the respective heads116A,116B, and116C remain the same. Each cannula110A,110B,110C has a channel120A,120B,120C that extends the length of the cannula110A,110B,110C, through the respective heads116A,116B,116C and respective tubes112A,112B,112C, with an opening at each end. The difference in diameters114A,114B,114C between the tubes112A,112B,112C of the cannulas110A,110B,110C enables the cannulas110A,110B, and110C to be nested within one another. For example, the tube112A of the cannula110A may be placed within the channel120B of the cannula110B or the channel120C of the cannula110C, and the tube112B of the cannula110B may be placed within the channel120C of the cannula110C. In various aspects of the present disclosure, the example handle120of the cannula system100includes a gripping portion124and an opening122. In some aspects, the gripping portion124may have suitable shapes other than that illustrated and/or may include additional material for enhancing grip, such as rubber, on the outer surface. The opening122of the handle120is configured according to a locking mechanism of each cannula110A,110B,110C in order to enable interlocking a respective cannula110A,110B,110C with the handle120. For example, in some aspects, such as the one illustrated, each locking mechanism is a twist lock mechanism such that a first cannula (e.g., the cannula110A) is twisted or rotated relative to a second cannula (e.g., the cannula110B) in order to lock the first and second cannulas. In such an example, the twist lock mechanism may include a male lock component and a female lock component or opening. The female lock opening allows the male lock component to pass through when the male lock component is in one orientation, but does not let it pass through when the male lock component is rotated relative to the female lock opening. In an example, each cannula110A,110B,110C includes a male lock component118A,118B,118C that includes a cross-sectional shape with two straight sides and two curved sides. Each cannula110A,110B,110C also includes a female lock component or opening (not illustrated), which will be described in more detail below. In various aspects, the example opening122of the handle120has the same corresponding cross-sectional shape as each male lock component118A,118B, and118C. In such aspects, when the male lock component118A of the cannula110A is oriented to match its straight and curved sides with the opening122, the male lock component118A may pass through the opening122. However, if the cannula110A is rotated once the male lock component118A is through the opening122, the straight and curved sides no longer match up, and the male lock component118A cannot pass back through the opening122. The cannula110A is accordingly interlocked with the handle120. FIGS.2A and2Billustrate a top view of an example cannula210placed through an opening in the example handle200in an unlocked and locked position, respectively, according to an aspect of the present disclosure. InFIG.2A, the cross-section of the male lock component of the example cannula210matches the opening in the handle200. However, inFIG.2B, the example cannula210is rotated and the cross-section of the male lock component no longer matches the opening in the handle200. The male lock component of the example cannula210, therefore, may no longer pass through the opening and the cannula210is interlocked with the handle200. FIGS.2A and2Badditionally illustrate a top view of an example female lock component or opening220of the example cannula210. In various aspects, the example female lock opening220is similar to the opening of the handle200in that it has a cross-sectional shape that matches the male lock component in one orientation, but not when the male lock component is rotated relative to the female lock opening220. In some aspects, the female lock opening220includes a notch in the inner wall of the female lock opening220that is configured to accept the male lock component. Each cannula110A,110B,110C in the cannula system100can be interlocked with any other cannula110A,110B,110C in the cannula system100. For example,FIGS.3A and3Billustrate two example orientations of the cannulas110A,110B, and110C. In the example orientation ofFIG.3A, the cannula110C is interlocked with the handle120. The cannula110B is nested within, and interlocked with, the cannula110C. And, the cannula110A is nested within, and interlocked with, the cannula110B. In comparison, the example orientation ofFIG.3Bincludes the cannula110C interlocked with the handle120; however, the cannula110A is nested within, and interlocked with, the cannula110C, while the cannula110B remains unused and off to the side. In other examples, the cannula110B or the cannula110A may be interlocked with the handle120and the cannula110C may be unused. The ability to interlock any of the cannulas110A,110B,110C with each other or with the handle120provides a surgeon with greater flexibility in choosing which cannulas to use for a surgical procedure than conventional cannula systems. This increased flexibility may enable a surgeon to make smaller incisions in a patient since the surgeon is not required to use the largest cannula in a set. The increased flexibility may also lessen the weight of, and thus the force applied on the patient by, the nested cannulas since the surgeon may skip cannula sizes when nesting one cannula within another. In some aspects of the present disclosure, the respective locking mechanisms of each cannula110A,110B,110C may be identical or substantially identical. Stated differently, in such aspects, each male lock component118A,118B,118C of each respective cannula110A,110B,110C in the cannula system100are substantially identical, and each female lock opening220of each respective cannula110A,110B,110C in the cannula system100are substantially identical. In an example, each male lock component118A,118B,118C and each female lock opening220are sized equally regardless of the size of their respective cannula110A,110B,110C. In such aspects, the cannulas110A,110B, and110C can be considered to have a universal locking mechanism since the locking mechanism of each is the same. In other aspects, the cannulas110A,110B, and110C could have identical or substantially identical male lock components118A,118B, and118C, but different female lock openings220. In other aspects still, the cannulas110A,110B, and110C could have different male lock components118A,118B, and118C, but identical or substantially identical female lock openings220. In some aspects, the smallest cannula (e.g., the cannula110A) in the system100does not have a female lock opening220since no other cannula (e.g., the cannulas110B and110C) can nest within the smallest cannula. In some aspects of the present disclosure, a respective locking mechanism of each cannula of the cannula system100may be a squeeze lock mechanism.FIG.4Ashows example cannulas410A and410B configured with an example squeeze lock mechanism. For instance, the example cannula410A includes gaps414A and414A′ that extend through the head416A of the example cannula410A into a portion of the tube418of the example cannula410A. The gaps414A and414A′ enable the cannula410A to be compressed inward by applying a force on either side of the cannula410to reduce the size of the gaps414A and414A′. For example, a force may be applied to the head416A of the cannula410A in the direction of the arrows illustrated on the example cannula410B. The example cannula410A may also include an extension412A. Accordingly, the combination of the ability to be flexed inward and the extension412A enable the example cannula410A to be interlocked with the handle400. For instance, when the cannula410A is compressed inward, the extension412A may be able to pass through the opening420(FIG.4B) of the handle410. However, when the compressive force is released after the extension412A passes through the opening420, the extension412A extends past the outer bounds of the opening420and may not pass back through the opening420. Thus, this enables the handle400to be interlocked with the cannula410. Due to the gaps412A and412A′, the extension412A includes multiple extension components that are broken up by the gaps412A and412A′. In some examples, the extension412A may extend fully around the perimeter of the cannula410A, except for the gaps412A and412A′. In some examples, the extension412A may have a circular cross-section corresponding to the circular opening420of the handle400as illustrated inFIG.4B. In such examples, the cannula410A may rotate freely about its axis in either direction since the opening420is circular. In other examples, the extension412A may have other cross-sectional shapes that correspond to the cross-sectional shape of the opening420of the handle400, for instance, a square. In such an instance, the cannula410A may include an extension412A only on one or more sides of the square, such as on two sides. In such an instance, the cannula410A is prevented from rotating about its axis since the opening420is square. Similar to how the example cannula410A may be interlocked with the handle400, two cannulas (e.g., the cannulas410A and410B) may be interlocked with one another by way of the squeeze lock mechanism. In such instances, the extension412A may be considered a male lock component and the head416A of the cannula410A may have a female lock component, such as an opening and a notch. For example, the example cannula410B similarly includes gaps414B and414B′ and an extension412B consistent with the description above for the cannula410A. Accordingly, the cannula410B may be compressed inward by a force in the direction of the illustrated arrows on the head416B of the cannula410B. The compressive force decreases the gaps414B and414B′ and thus allows the extension412B to pass through the opening of the female lock component in the head416A of the cannula410A. Once the extension412B passes through the opening, the compressive force may be released, increasing the gaps414B and414B′ and allowing the extension412B to enter a notch within the inner wall of the head416A of the cannula410A. When the extension412B is within the notch, it may not pass back through the opening, and thus the cannula410B is interlocked with the cannula410A. In some examples, the notch of the female lock component in the head416A of the cannula410A may extend around the entire perimeter of the inner wall of the head416A. Such examples may enable the cannula410B to rotate freely about its axis when it is nested within, and interlocked with, the cannula410A. For instance, in some examples, the cross-section of the notch and of the extension412B may be correspondingly circular. In some examples, the notch may extend less than the entire perimeter of the inner wall. Such examples may prevent or limit the cannula410B from rotating about its axis when it is nested within, and interlocked with, the cannula410A. For instance, the cannula410A may include multiple notches that correspondingly match the multiple extension components of the extension412B on the cannula410B. Thus, when the extension components are placed within their respective notches, the extension components are locked within the notch and the cannula410B is prevented from rotating. In some examples, each notch of the multiple notches may be sized larger than each extension component, although the notches are separate and do not join together. Thus, in such examples, each extension component has space to move within its respective notch and the cannula410B may partially rotate about its axis in either direction, though it may not freely rotate a complete revolution. In other examples, the opening and notch of the example cannula410A may have other cross-sectional shapes that correspond to the cross-sectional shape of the extension412B of the cannula410B, for instance, a square. In such an instance, the cannula410B may include an extension412B only on one or more sides of the square, such as on two sides. In such an instance, the cannula410B is prevented from rotating about its axis when it is nested within, and interlocked with, the cannula410A because of the square cross-sectional shape. Each cannula410A,410B may be interlocked with any other cannula410A,410B in an example cannula system100including respective squeeze lock mechanisms. In some aspects, each respective squeeze lock mechanism on each cannula410A,410B may be sized equally. In some aspects of the present disclosure, the respective locking mechanisms of the each cannula110A,110B,110C may be configured so as to enable an ordered release or disengagement of the nested and interlocked cannulas110A,110B,110C from one another. The advantages of such aspects may be exemplified by the following situation. A surgeon may insert the cannulas110A,110B, and110C in the orientation ofFIG.3Aat least partially into a patient. The surgeon may later desire to only disengage and remove the cannula110A from the cannula110B, while the cannula110B remains nested within and interlocked with the cannula110C and the cannula110C remains interlocked with the handle120. In some aspects, a surgeon may need to immobilize the cannula110B (e.g., hold it with one hand) while disengaging or removing (e.g., with the surgeon's other hand) the cannula110A so that the cannula110B does not also disengage from the cannula110C and the cannula110C does not disengage from the handle120. It would be advantageous, however, if the surgeon were able to disengage the cannula110A using only one hand to free the surgeon's other hand during surgery. Accordingly, aspects with cannulas110A,110B,110C that enable an ordered release include respective locking mechanisms that require different amounts of force to disengage the various combinations of nesting orientations of the cannulas110A,110B, and110C and the handle120. For example, in the orientation ofFIG.3A, it may require less force to disengage the cannula110A from the cannula110B than it does to disengage the cannula110B from the cannula110C. And it requires less force to disengage cannulas110A,110B, or110C from one another than it does to disengage a cannula110B,110B, or110C from the handle120. In this way, the surgeon can disengage and remove the cannula110A from the cannula110B without having to immobilize the cannula110B, and without disengaging the cannula110B from the cannula110C or the cannula110C from the handle120, by applying a force (e.g., twist or pull) to the cannula110A that is sufficient to disengage the cannula110A from the cannula110B but insufficient to disengage the cannula110B from the cannula110C or the cannula110C from the handle120. The surgeon may apply such force using only one hand. FIGS.6to9illustrate views of an example cannula system600including cannulas602A,602B, and602C having respective twist lock mechanisms constructed for ordered release. Referring toFIG.6, in various aspects, the example cannula system600includes a cannula602A, a cannula602B, and a cannula602C, though in other aspects the cannula system600may include additional cannulas, as described similarly for the cannula system100discussed above. In at least some aspects, the system600includes a handle120. The handle120is described above. The cannulas602A,602B, and602C are sized in a sequence of smaller cannulas to larger cannulas. For instance, the cannula602C includes a tube112C which has a larger diameter than the tube112B of the cannula602B, which has a larger diameter than the tube112A of the cannula602A. In aspects in which the cannula system600includes more than three cannulas602A,602B,602C, the sequence may further include a cannula larger than the cannula602C or a cannula smaller than the cannula602A, and so forth. In at least some aspects, the cannula602A includes a male lock component having a thread606A and a cam608. The male lock component of the cannula602A may be integral with or attached to a head604A of the cannula602A. In some examples, the head604A may include teeth or another suitable grip-enhancing construction or material. In at least some aspects, the thread606A is split into two portions. For example, the thread606A may be split by opposing flat surfaces612A and802A (FIG.8).FIG.7illustrates the cannula602A rotated ninety degrees relative to the illustrated cannula602A inFIG.6to show the thread pitch of the thread606A.FIG.8illustrates a bottom view of the cannula602A. In at least some aspects, the cam608may have the shape illustrated inFIG.8, though in other aspects may have other suitable shapes.FIG.9illustrates a top view of the cannula602A showing an opening to a channel902A that extends through the tube112A of the cannula602A. In this example, the cannula602A is the smallest cannula in the system600and does not include a female lock component or opening. Returning toFIG.6, in various aspects, the cannula602B includes a male lock component having a thread606B. In at least some examples, the male lock component of the cannula602B does not include a cam. In some aspects, the male lock component of the cannula602B instead includes a support member610. In such aspects, the support member610can help in maintaining concentricity of the cannula602B with the cannula602C when nested within the cannula602C.FIG.8illustrates a bottom view of the cannula602B. In some aspects, such as the illustrated aspect, the support member610may have a circular shape. Returning toFIG.6, the male lock component of the cannula602B may be integral with or attached to a head604B of the cannula602B. In some examples, the head604B may include teeth or another suitable grip-enhancing construction or material. In at least some aspects, the thread606B is split into two portions. For example, the thread606B may be split by opposing flat surfaces612B and802B (FIG.8).FIG.7illustrates the cannula602B rotated ninety degrees relative to the illustrated cannula602B inFIG.6to show the thread pitch of the thread606B. In at least some aspects, the thread pitch of the thread606B is equal to the thread pitch of the thread606A of the cannula602A.FIG.9illustrates a top view of the cannula602B showing an opening to a channel902B that extends through the tube112B of the cannula602B. The cannula602B includes a female lock component/opening having a notch904B. The notch904B has a shape that suitably corresponds to the cam608of the cannula602A. In some aspects, the female lock component/opening of the cannula602B includes a female thread (not shown) that extends into the sidewalls906B and908B of the head604B. Returning toFIG.6, in various aspects, the cannula602C includes a male lock component having a thread606C. The male lock component of the cannula602C may be integral with or attached to a head604C of the cannula602C. In some examples, the head604C may include teeth or another suitable grip-enhancing construction or material. In at least some aspects, the thread606C is split into two portions. For example, the thread606C may be split by opposing flat surfaces612C and802C (FIG.8).FIG.7illustrates the cannula602C rotated ninety degrees relative to the illustrated cannula602C inFIG.6to show the thread pitch of the thread606C. In at least some aspects, the thread606C has a smaller thread pitch than the thread606A of the cannula602A and the thread606B of the cannula602B.FIG.8illustrates a bottom view of the cannula602C. FIG.9illustrates a top view of the cannula602C showing an opening to a channel902C that extends through the tube112C of the cannula602C. The cannula602C includes a female lock component/opening. In at least some aspects, the female lock component/opening of the cannula602C includes a notch904B. In such aspects, the notch904B is sized and shaped such that it does not suitably correspond to the size and shape of the cam608of the cannula602A. The notch904B may, in some instances, be sized and shaped to correspond to the support member610of the cannula602B, which may help the main concentricity of the cannula602B and the cannula602C when the cannula602B is nested within the cannula602C. In at least some aspects, the female lock component/opening of the cannula602C includes a female thread (not shown) that extends into the sidewalls906C and908C of the head604C. The interaction of the cannulas602A,602B, and602C will now be described. The cam608of the male lock component of the cannula602A can engage with the sidewall of the notch904B of the female lock component/opening of the cannula602B, for instance by rotating the cannula602A when nested within the cannula602B. The engagement of the cam608with the sidewall of the notch904B interlocks the cannula602A with the cannula602B. The cam608, however, will not engage with the sidewall of the notch904C of the female lock component/opening of the cannula602C. The thread606A of the male lock component of the cannula602A does not engage the female thread extending into the sidewalls906B and908B of the female lock component/opening of the cannula602B. Rather, the thread606A merely fits within the female thread of the cannula602B. For example, if the cannula602A is rotated just past the cam608becoming disengaged from the sidewall of the notch904B, the female thread of the cannula602B will prevent a surgeon from translating the cannula602A along the long axis of the cannulas602A and602B to remove the cannula602A from the cannula602B; however, the cannula602A will be loose to translate back and forth along that long axis because the thread606A is not engaged with the female thread of the cannula602B. Once the cannula602A is rotated further, the thread606A becomes clear of the female thread of the cannula602B and the surgeon may remove the cannula602A from the cannula602B. In this way, while the female thread of the cannula602B does not contribute to the engagement of the cannula602A with the cannula602B, and therefore does not contribute to the torque required to disengage the cannula602A from the cannula602B, the female thread of the cannula602B can help maintain the connection between the cannula602A and the cannula602B during surgery if the cam608were to accidentally become disengaged from the sidewall of the notch904B. Conversely, the thread606A of the cannula602A does engage the female thread of the female lock component/opening of the cannula602C. The engagement of the thread606A with the female thread interlocks the cannula602A with the cannula602C. As stated above, the cam608of the cannula602A does not engage with the female lock component/opening of the cannula602C. The thread606A of the cannula602A is also able to interlock with the handle120at the opening122. In addition, the thread606B of the male lock component of the cannula602B engages the female thread of the female lock component/opening of the cannula602C. The engagement of the thread606B with the female thread interlocks the cannula602B with the cannula602C. The thread606B is also able to interlock with the handle120at the opening122. The thread606C of the male lock component of the cannula602C is additionally able to interlock with the handle120at the opening122. The above-described respective male lock components and female lock components/openings of the cannulas602A,602B, and602C enable for an ordered release or disengagement of the cannulas602A,602B, and602C. In an example, the cannula602A is nested within, and interlocked with the cannula602B, which is nested within, and interlocked with the cannula602C, which is interlocked with the handle120. In this example, it requires less rotational force to disengage the cam608of the cannula602A from the notch904B of the female lock component/opening of the cannula602B than it does to disengage the thread606B of the cannula602B from the female thread of the female lock component/opening of the cannula602C. It also requires less rotational force to disengage the cam608from the notch904B than it does to disengage the thread606C of the cannula602C from the handle120. In this way, a surgeon can disengage and remove the cannula602A from the cannula602B using one hand without disengaging the cannula602B or the cannula602C. Continuing with this example with the cannula602A removed, it requires less rotational force to disengage the thread606B of the cannula602B from the female thread of the female lock component/opening of the cannula602C than it does to disengage the thread606C of the cannula602C from the handle120. In this way, a surgeon can disengage and remove the cannula602B from the cannula602C using one hand without disengaging the cannula602C. This is true whether or not the cannula602A is interlocked with cannula602B. In some instances, the cannula602A may be nested within, and interlocked with, the cannula602C, which is interlocked with the handle120. In such instances, it requires less rotational force to disengage the thread606A of the cannula602A from the female thread of the female lock component/opening of the cannula602C than it does to disengage the thread606C of the cannula602C from the handle120. In this way, a surgeon can disengage and remove the cannula602A from the cannula602C using one hand without disengaging the cannula602C. In some instances, the cannula602A may be nested within, and interlocked with, the cannula602B, which is interlocked with the handle120. In such instances, it requires less rotational force to disengage the cam608of the cannula602A from the notch904B of the female lock component/opening of the cannula602B than it does to disengage the thread606B of the cannula602B from the handle120. In this way, a surgeon can disengage and remove the cannula602A from the cannula602B using one hand without disengaging the cannula602B. FIGS.10to13illustrate views of an example cannula system1000including cannulas1002A,1002B, and1002C having respective spring-and-thread lock mechanisms constructed for ordered release. Referring toFIG.10, in various aspects, the example cannula system1000includes a cannula1002A, a cannula1002B, and a cannula1002C, though in other aspects the cannula system1000may include additional cannulas, as described similarly for the cannula systems100and600discussed above. In at least some aspects, the system1000includes a handle120. The handle120is described above. The cannulas1002A,1002B, and1002C are sized in a sequence of smaller cannulas to larger cannulas. For instance, the cannula1002C includes a tube112C, which has a larger diameter than the tube112B of the cannula1002B, which has a larger diameter than the tube112A of the cannula1002A. In aspects in which the cannula system1000includes more than three cannulas1002A,1002B,1002C, the sequence may further include a cannula larger than the cannula1002C or a cannula smaller than the cannula1002A, and so forth. In at least some aspects, the cannula1002A includes a male lock component having a thread1006A and a spring1008A. At least a portion of the male lock component of the cannula1002A may be integral with or attached to a head1004A of the cannula1002A. In some examples, the head1004A may include teeth or another suitable grip-enhancing construction or material. In at least some aspects, the spring1008A is a canted coil spring. In various examples, the spring1008A is partially positioned within a notch of the male lock component of the cannula1002A such that the spring1008A extends beyond a directly adjacent surface of the male lock component and is prevented from axial movement along the cannula1002A. In some aspects, the spring1008A is attached to the male lock component of the cannula1002A. In other aspects, the spring1008A is merely maintained within the notch of the male lock component of the cannula1002A and is not otherwise attached to the male lock component. In at least some aspects, the thread1006A of the male lock component of the cannula1002A is split into two portions. For example, the thread1006A may be split by opposing flat surfaces1012A and1202A (FIG.12).FIG.11illustrates the cannula1002A rotated ninety degrees relative to the illustrated cannula1002A inFIG.10to show the thread pitch of the thread1006A.FIG.12illustrates a bottom view of the cannula1002A that shows the opposing flat surfaces1012A and1202A. The bottom view also illustrates that only a portion of the spring1008A is visible due to the spring1008A being positioned partially within the notch of the male lock component of the cannula1002A.FIG.13illustrates a top view of the cannula1002A showing an opening to a channel1002A that extends through the tube112A of the cannula1002A. In this example, the cannula1002A is the smallest cannula in the system1000and does not include a female lock component or opening. Returning toFIG.10, in at least some aspects, the cannula1002B includes a male lock component having a thread1006B and a spring1008B. At least a portion of the male lock component of the cannula1002B may be integral with or attached to a head1004B of the cannula1002B. In some examples, the head1004B may include teeth or another suitable grip-enhancing construction or material. In at least some aspects, the spring1008B is a canted coil spring. In various examples, the spring1008B is partially positioned within a notch of the male lock component of the cannula1002B such that the spring1008B extends beyond a directly adjacent surface of the male lock component and is prevented from axial movement along the cannula1002B. In some aspects, the spring1008B is attached to the male lock component of the cannula1002B. In other aspects, the spring1008B is merely maintained within the notch of the male lock component of the cannula1002B and is not otherwise attached to the male lock component. In at least some aspects, the thread1006B of the male lock component of the cannula1002B is split into two portions. For example, the thread1006B may be split by opposing flat surfaces1012B and1202B (FIG.12).FIG.11illustrates the cannula1002B rotated ninety degrees relative to the illustrated cannula1002B inFIG.10to show the thread pitch of the thread1006B.FIG.12illustrates a bottom view of the cannula1002B that shows the opposing flat surfaces1012B and1202B. The bottom view also illustrates that only a portion of the spring1008B is visible due to the spring1008B being positioned partially within the notch of the male lock component of the cannula1002B.FIG.13illustrates a top view of the cannula1002B showing an opening to a channel1002B that extends through the tube112B of the cannula1002B. The top view also shows a female lock component/opening of the cannula1002B. In at least some aspects, the female lock component/opening of the cannula1002B includes a notch1304B. The notch1304B is sized and shaped in relation to the spring1008A of the cannula1002A. In at least some aspects, the female lock component/opening of the cannula1002B includes a notch1306B. The notch1306B is sized and shaped to enable space for the thread1006A of the cannula1002A, though the notch1306B does not engage the thread1006A. Returning toFIG.10, in at least some aspects, the cannula1002C includes a male lock component having a thread1006C. In this example, the cannula1002C is the largest cannula in the set of cannulas of the system1000and therefore its male lock component does not need to include a spring since the cannula1002C cannot nest within any other cannula in the set, though the male lock component of the cannula1002C could include a spring. At least a portion of the male lock component of the cannula1002C may be integral with or attached to a head1004C of the cannula1002C. In some examples, the head1004C may include teeth or another suitable grip-enhancing construction or material. In at least some aspects, In at least some aspects, the thread1006C of the male lock component of the cannula1002C is split into two portions. For example, the thread1006C may be split by opposing flat surfaces1012C and1202C (FIG.12).FIG.11illustrates the cannula1002C rotated ninety degrees relative to the illustrated cannula1002C inFIG.10to show the thread pitch of the thread1006C. In various aspects, the thread1006A of the cannula1002A, the thread1006B of the cannula1002B, and the thread1006C of the cannula1002C have equal thread pitches.FIG.12illustrates a bottom view of the cannula1002C that shows the opposing flat surfaces1012C and1202C. FIG.13illustrates a top view of the cannula1002C showing an opening to a channel1002C that extends through the tube112C of the cannula1002C. The top view also shows a female lock component/opening of the cannula1002C. In at least some aspects, the female lock component/opening of the cannula1002C includes a notch1304C. The notch1304C is sized and shaped in relation to the spring1008A of the cannula1002A and the spring1008B of the cannula1002B. Stated differently, the spring1008A and the spring1008B may be sized and shaped the same so that the notch1304C is sized and shaped in relation to each the spring1008A and the spring1008B. In at least some aspects, the female lock component/opening of the cannula1002C includes a notch1306C. The notch1306C is sized and shaped to enable space for the thread1006A of the cannula1002A or the thread1006B of the cannula1002B, though the notch1306C does not engage the thread1006A nor the thread1006B. The interaction of the cannulas1002A,1002B, and1002C will now be described. The spring1008A of the male lock component of the cannula1002A can engage with the sidewall of the notch1304B of the female lock component/opening of the cannula1002B, for instance by translating (e.g., pushing) the cannula1002A along an axial direction when nested within the cannula1002B. The spring1008A is sized larger than the notch1304B, and as the spring1008A is forced into the notch1304B, the spring1008A is compressed. The counteracting force of the compressed spring1008A against the sidewall of the notch1304B interlocks the cannula1002A with the cannula1002B. To disengage the compressed spring1008A from the sidewall of the notch1304B, the cannula1002A may be translated (e.g., pulled) along the opposite axial direction as when the spring1008A was engaged with the sidewall. The spring1008A of the male lock component of the cannula1002A can engage with the sidewall of the notch1304C of the female lock component/opening of the cannula1002C in a similar manner, which interlocks the cannula1002A with the cannula1002C. The thread1006A of the male component of the cannula1002A is able to interlock (e.g., via rotational engagement) with the handle120at the opening122. In addition, the spring1008B of the male lock component of the cannula1002B can engage with the sidewall of the notch1304B of the female lock component/opening of the cannula1002C, for instance by translating (e.g., pushing) the cannula1002B along an axial direction when nested within the cannula1002C. The spring1008B is sized larger than the notch1304C, and as the spring1008B is forced into the notch1304C, the spring1008B is compressed. The counteracting force of the compressed spring1008B against the sidewall of the notch1304C interlocks the cannula1002B with the cannula1002C. To disengage the compressed spring1008B from the sidewall of the notch1304C, the cannula1002B may be translated (e.g., pulled) along the opposite axial direction as when the spring1008B was engaged with the sidewall. The thread1006B of the male component of the cannula1002B is able to interlock (e.g., via rotational engagement) with the handle120at the opening122. The thread1006C of the male component of the cannula1002C is also able to interlock (e.g., via rotational engagement) with the handle120at the opening122. The above-described respective male lock components and female lock components/openings of the cannulas1002A,1002B, and1002C enable for an ordered release or disengagement of the cannulas1002A,1002B, and1002C. In an example, the cannula1002A is nested within, and interlocked with the cannula1002B, which is nested within, and interlocked with the cannula1002C, which is interlocked with the handle120. In this example, it requires less translational (e.g., pulling) force to disengage the spring1008A of the cannula1002A from the sidewall of the notch1304B of the female lock component/opening of the cannula1002B than it does to disengage the spring1008B of the cannula1002B from the sidewall of the notch1304C of the female lock component/opening of the cannula1002C. Additionally, since the cannula1002A is translated (e.g., pulled) to disengage and remove it from the cannula1002A, such translational motion does not apply sufficient rotational force to disengage the thread1006C of the cannula1002C from the handle120. In this way, a surgeon can disengage and remove the cannula1002A from the cannula1002B using one hand without disengaging the cannula1002B or the cannula1002C. Continuing with this example with the cannula1002A removed, the spring1008B of the cannula1002B can be disengaged from the sidewall of the notch1304C of the female lock component/opening of the cannula1002C by translating (e.g., pulling) the cannula1002B along the axial direction. Since the cannula1002B is translated (e.g., pulled) to disengage and remove it from the cannula1002C, such translational motion does not apply sufficient rotational force to disengage the thread1006C of the cannula1002C from the handle120. In this way, a surgeon can disengage and remove the cannula1002B from the cannula1002C using one hand without disengaging the cannula1002C. In some instances, the cannula1002A may be nested within, and interlocked with, the cannula1002C, which is interlocked with the handle120. The spring1008A of the cannula1002A can be disengaged from the sidewall of the notch1304C of the female lock component/opening of the cannula1002C by translating (e.g., pulling) the cannula1002A along the axial direction. Since the cannula1002A is translated (e.g., pulled) to disengage and remove it from the cannula1002C, such translational motion does not apply sufficient rotational force to disengage the thread1006C of the cannula1002C from the handle120. In this way, a surgeon can disengage and remove the cannula1002A from the cannula1002C using one hand without disengaging the cannula1002C. In some instances, the cannula1002A may be nested within, and interlocked with, the cannula1002B, which is interlocked with the handle120. The spring1008A of the cannula1002A can be disengaged from the sidewall of the notch1304B of the female lock component/opening of the cannula1002B by translating (e.g., pulling) the cannula1002A along the axial direction. Since the cannula1002A is translated (e.g., pulled) to disengage and remove it from the cannula1002B, such translational motion does not apply sufficient rotational force to disengage the thread1006B of the cannula1002B from the handle120. In this way, a surgeon can disengage and remove the cannula1002A from the cannula1002B using one hand without disengaging the cannula1002B. In some aspects of the present disclosure, each cannula in the set of cannulas of the provided system (e.g., the cannula system100,600, or1000) may be constructed of a particular material to help enable an ordered release of nested and interlocked cannulas. For example, in the example cannula system600, the cannula602A and the cannula602B may be constructed of a heat treated 17-4 stainless steel, the cannula602C may be constructed of a Custom 455® heat treated stainless steel, and the handle120may be constructed of a commercially pure, grade4titanium (titanium CP4). Friction between the different materials in this example helps differentiate the rotational force required to disengage the one cannula from another. For instance, the interface between Custom 455® heat treated stainless steel and titanium CP4 has a greater static friction coefficient than the interface between heat treated 17-4 stainless steel and heat treated 17-4 stainless steel, which leads to a greater force needed to overcome the friction between Custom 455® heat treated stainless steel and titanium CP4. FIG.5shows an example procedure500that includes inserting nested cannulas into a drilled bone hole, according to an aspect of the present disclosure. Alternatively, the procedure500may be used external to the bone, protecting the surrounding tissues (e.g., in areas of sensitive soft tissue structures like nerves, where repeated insertion of instrumentation is most likely to cause harm and where surgical duration is important) for the sharp instruments passing through the cannulas. In other aspects, many other methods of performing the acts described in connection withFIG.5may be used. For example, the order of some of the steps may be changed, certain steps may be combined with other steps, one or more of the steps may be repeated, and some of the steps described may be optional. In the example procedure500, a surgeon may first determine the cannula sizes that the surgeon will need. In some instances, the surgeon may then nest the cannulas accordingly, if needed, for the size of the first instrument to be used. For example, the surgeon may nest the cannula530B within the cannula530A and the cannula530C within the cannula530B so that the size of the cannula530C may be used with the first instrument. In some instances, the surgeon may then drill a hole in the bone510corresponding to the largest cannula needed. For example, the cannula530A with the tube532is illustrated as the largest cannula used in the example procedure500. Thus, in this instance, the bone hole will be drilled corresponding to the size of the tube532. In some instances, the surgeon may then interlock the handle with largest, outermost cannula to be inserted. For example, the surgeon may interlock the handle520with the cannula530A. The surgeon may then insert the one or more cannulas through the bone hole. For example, the surgeon may insert the nested cannulas530A,530B, and530C into the hole in the bone510. In some instances, the surgeon may then insert an instrument through the innermost cannula's channel and perform a portion of the example procedure500. For example, the surgeon may insert an instrument through the channel of the cannula530C. At subsequent points in the example procedure500, the surgeon may remove one or more cannulas, or insert one or more cannulas, so that the surgeon may use a larger or smaller instrument that requires a larger or smaller cannula channel. For example, the surgeon may remove the cannula530C from the cannula530B, for instance by twisting the cannula530C to disengage the locking mechanism with cannula530B, so that the surgeon may access the channel in the cannula530B with a second instrument. At a subsequent time in the example procedure500, the surgeon may then remove the cannula530B from the cannula530A, for instance by twisting the cannula530B to disengage the locking mechanism with cannula530A, so that the surgeon may access the channel in the cannula530A with a third instrument. At a subsequent time in the example procedure500, the surgeon may then insert the cannula530C into the cannula530A and interlock them together, for instance by twisting the cannula530C to engage the locking mechanism, so that the surgeon may again use the first instrument. Without further elaboration, it is believed that one skilled in the art can use the preceding description to utilize the claimed inventions to their fullest extent. The examples and embodiments disclosed herein are to be construed as merely illustrative and not a limitation of the scope of the present disclosure in any way. It will be apparent to those having skill in the art that changes may be made to the details of the above-described embodiments without departing from the underlying principles discussed. In other words, various modifications and improvements of the embodiments specifically disclosed in the description above are within the scope of the appended claims. For example, any suitable combination of features of the various embodiments described is contemplated.

11857218

DETAILED DESCRIPTION Various exemplary embodiments will now be described more fully with reference to the accompanying drawings in which some exemplary embodiments are illustrated. In the drawings, the thicknesses of layers and regions may be exaggerated for clarity. Accordingly, while exemplary embodiments are capable of various modifications and alternative forms, embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit exemplary embodiments to the particular forms disclosed, but on the contrary, exemplary embodiments are to cover all modifications, equivalents, and alternatives falling within the scope of the invention. Like numbers refer to like elements throughout the description of the figures. It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of exemplary embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). The terminology used herein is for the purpose of describing only particular embodiments and is not intended to be limiting of exemplary embodiments. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof. Spatially relative terms, e.g., “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or a relationship between a feature and another element or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the Figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, for example, the term “below” can encompass both an orientation which is above as well as below. The device may be otherwise oriented (rotated 90 degrees or viewed or referenced at other orientations) and the spatially relative descriptors used herein should be interpreted accordingly. It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may in fact be executed substantially concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which exemplary embodiments belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Exemplary embodiments are directed to subcutaneous implantation tools and methods of implanting subcutaneous micro-devices.FIGS.1A to10illustrate various exemplary embodiments of such subcutaneous implantation tools. FIG.1shows the implantable device10, aligned longitudinally with the handle100, arranged for the insertion of device10into the channel102of the handle100. The proximal end20of the device is inserted into the distal end108of the channel102of the handle and is advanced proximal until the proximal end30of the device is located adjacent an internal stop surface (not illustrated) within the handle100. At this point, the distal end20of the device will be adjacent the distal end108of the handle100. The open upper portion of the channel102allows visual verification that the device10is properly inserted into the channel. The tunneler104extends distally of the distal end108of channel102. The distal end106of the tunneler is placed into the incision made by the incision tool with its upper surface facing outward of the patient's body and advanced to provide blunt dissection of the subcutaneous tissue to a point where the distal end20of the device is adjacent the opening of the incision. The handle100is then rotated180degrees so that the tunneler104is then above the device (outward relative to the patient's skin). This allows upward pressure on the handle to assist in temporarily enlarging the incision and assures that the device will not escape as advanced distally into the tissue. The device10is then advanced by distal movement of the plunger illustrated inFIG.5Bwithin the channel102and along the tunneler104until it is properly located within the tissue, displaced distally a short distance from the opening of the incision. The logo112assists in reminding the physician to rotate the handle prior to insertion of the plunger and advancement of the device. FIG.2shows the device10in more detail. In this view it can be seen that the device comprises two electrodes12and14, located adjacent the proximal and distal ends, respectively, of the device. When implanted, electrode12, located on the upper surface16of the device preferably faces outward toward the skin. As such, when the device is placed into the handle as discussed above, the electrode12faces downward and is not visible through the open upper portion of the channel, allowing verification of proper insertion into the handle. The exemplary device10as illustrated generally takes the form of an elongated rectangular prism having rounded corners and a rounded distal end portion. The rounded distal end of the device assists in allowing it to advance into body tissue, providing blunt dissection of the tissue as it advances. Because the cross section of the device is substantially greater than the cross section of the tunneler, the device will be located snugly within the tissue, reducing the chances for the formation of air bubbles adjacent the electrodes and also assisting in maintaining the device in its desired position. The device has length (L), width (W) and depth (D) as illustrated. In this particular embodiment, the with is greater than the depth, providing radial asymmetry along the longitudinal axis of the device and assisting in maintaining the device in its proper orientation with upper surface16facing outward after implant. A suture hole18may optionally be provided at the proximal end of the device to allow the physician to suture it to underlying tissue if desired. Projections22may optionally be provided to prevent longitudinal movement of the device after implant. As discussed above, the inner surface of the channel of the handle is preferably configured to correspond to the outer configuration of the device. As discussed below in more detail, the configuration of the channel of the handle is configured to engage the rounded corners of the device, preventing rotation of the device within the handle. FIG.3illustrates the incision tool200, which is provided with a curved plastic handle210fitted with a flat, pointed blade220having a width equal to the desired width of the incision. The handle is designed to be comfortably held in a position allowing the blade to be advanced through the skin at a shallow angle, avoiding damage to underlying muscle tissue. FIGS.4A,4B and4Cshow top, side and bottom views of the incision device200. As illustrated in4A, both the differing coloration of the finger grips234and232and the placement of the logo236on the upper surface assist the physician in assuring that the orientation of the blade is correct to provide the desired shallow penetration angle. FIGS.5A and5Bshow the handle100and the plunger300prior to insertion of the plunger into the handle. After rotation of the handle so that its upper surface bearing marking112now faces inward toward the patient's skin, the distal end302of plunger300is then inserted into an opening in the proximal end110of the handle and into the channel102of the handle. The plunger is provided with a groove306running the length of the lower surface of the plunger up to a distal stop surface discussed below. The opening in the proximal end of the handle includes a protrusion corresponding to the groove in the lower surface of the plunger, assuring its proper orientation within the handle. A marking308adjacent the proximal end of the plunger assists the physician in determining that the plunger is in the proper orientation for insertion into the handle. The plunger is advanced distally, pushing the device into the incision along the then inward facing surface of the tunneler. The device thus follows the path defined by the tunneler to assure proper placement within the tissue. After insertion of the device, the handle and plunger are removed. Various medical grade materials may be used to form the various parts of the subcutaneous implantation tool, for example, plastics, metals, rubber, sanitizable materials, etc. Exemplary embodiments of the subcutaneous implantation tool may be inexpensive, disposable, etc. The subcutaneous implantation tool may also be configured to be used with known automated injection systems, which use, e.g., compressed air or other inert gases in place of a manual plunger. FIGS.6A,6B,6C,6D and6Eare distal end, cut-away, top, bottom and proximal end views, respectively, of the tool handle100. In these views the projection114is visible. Projection114provides a distal facing stop surface limiting the insertion of the device10into the channel102. It further engages the slot in the lower surface of the plunger300, assuring proper orientation of the plunger within the handle. It also provides a proximal facing stop surface limiting distal movement of the plunger. The handle is also show as optionally provided with a slot116in its lower surface, through which advancement of the plunger and device can be observed. FIGS.7A and7Bare cross sectional views through the tool handle as illustrated inFIG.6C. In these views, the arrangement of the inner corner surfaces12,122,124and126can be seen. These surfaces, along with side surfaces128and130, are arranged to generally correspond to the corners and the side surfaces of the device, preventing rotation of the device within the handle. The distal facing surface of projection114is also visible in this view. FIGS.8A,8B,8C and8Dare distal end, cut-away, top and proximal end views, respectively, of the plunger of5B. In these figures, the configuration of the groove306can be seen, along with distally facing stop surface310, which engages with the proximal facing surface of protrusion114of the handle, to limit distal movement of the plunger. FIGS.9A,9B, and9Care cross sectional, side and bottom views. Respectively, of the plunger as illustrated inFIG.8D. In these views, the configuration of the groove306is visible in more detail. FIG.10is a flow chart illustrating a preferred embodiment of an insertion process according to the present invention. At500, the incision is made using the incision tool. At510, the handle carrying the device is inserted into the tissue such that the tunneler produces an elongated blunt incision along which the device may be advanced. In this step, the device is located outward of the tunneler relative to the patient's body. At520the handle, carrying the device is rotated so that the device is now inward of the tunneler relative to the patient's body. At530, the device is advanced by the plunger along the handle and along the then inward facing surface of the tunneler subcutaneously into the patient's body. Finally, at540, the handle and tunneler are removed. Exemplary embodiments thus described allow for subcutaneous implantation of devices that are minimally invasive. Note that exemplary embodiments may be used in both human and animal patients. Exemplary embodiments of the present invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the exemplary embodiments of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the invention.

11857219

DETAILED DESCRIPTION The systems and methods described herein may be used for a number of different procedures including, for example, kyphoplasty, vertebroplasty, and other bone augmentation procedures, including procedures in which an implant or other treatment is delivered to a tissue location, as well as possibly to compact, displace, remove or aspirate material from a tissue site. The systems and methods may also be used to treat tissue in other regions of the body, such as soft tissue or skin. The system may furthermore be used to deliver energy to tissue using radiofrequency ablation devices and techniques. In one embodiment, the present systems and methods advantageously allow off-axis kyphoplasty and vertebroplasty to avoid the expense and challenges involved in bi-pedicular access of the vertebra. By allowing a clinician to access cancellous bone radially offset from the longitudinal axis of an access cannula, the clinician is able to access volumes of the vertebra which are not accessible using conventional kyphoplasty and vertebroplasty approaches. The vertebra10includes two pedicles12, cortical bone14, and cancellous bone16, along with other bodily material (e.g., blood, marrow, and soft tissue). As a point of reference, the systems and methods of the present disclosure may be suitable or readily adapted by those of ordinary skill in the art for accessing a variety of bone sites. Thus, although the vertebra10is illustrated, it is to be understood that other bone sites may be accessed and treated by the systems and methods (e.g., pelvis, long bones, ribs, and sacrum). Referring toFIG.1, the system comprises an access cannula18and a steerable assembly20. The steerable assembly20comprises a steerable instrument22and a deformable conduit assembly26coupled to the steerable instrument22via a hub28. The deformable conduit assembly26includes a deformable conduit24. The steerable instrument22is capable of being removably and at least partially disposed in the deformable conduit24. The steerable instrument22is actuatable in order to deform the deformable conduit24into a deformed configuration from a normally straight configuration. One example of the deformed configuration is shown inFIG.1. By placing the deformable conduit24into the deformed configuration, other instruments, materials, etc. can be placed in the vertebra10through the deformable conduit24at a location that is offset from a longitudinal, straight access path created by the access cannula18. Referring toFIGS.2and3, the access cannula18is configured for being positioned and placed in the tissue at the target site along a straight, longitudinal access path using a stylet (not shown) coaxially disposed in the access cannula18. The access cannula18defines a lumen about a longitudinal axis A to provide access into the internal portion of the vertebra10. The access cannula18comprises a proximal end19configured for penetrating hard tissue and a distal end21configured for manipulation. The lumen is dimensioned to allow other instruments, such as the steerable instrument22and the deformable conduit24to pass there through. In certain embodiments, the access cannula18may range in size from 6 to 13 gauge. A cannula handle30, shown inFIG.8, may be attached to the proximal end19of the access cannula18for longitudinally or rotationally manipulating the access cannula18. The access cannula18preferably comprises surgical grade stainless steel, but may be made of known equivalent materials that are both biocompatible and substantially non-compliant, such as other medical alloys and plastics. A cannula hub31may be fixedly mounted to the proximal end19of the access cannula18to prevent the access cannula18from moving relative to the cannula handle30. The cannula hub31may be molded onto the proximal end19of the access cannula18or fixed thereto in other conventional ways. Likewise, the cannula hub31may be fixed to the cannula handle30by conventional methods such as adhesive, press fit, or the like. Referring toFIG.3, in some embodiments, a cannula adapter32is provided adjacent to the cannula handle30. The cannula adapter32is rotationally and axially locked to the access cannula18using conventional methods (via cannula handle30). The cannula adapter32may simply act as an extension of the cannula handle30. The cannula adapter32is configured to interact with the hub28of the deformable conduit assembly26. For example, the cannula adapter32may provide for releasably axially fixed attachment to the hub28, to prevent the access cannula18from moving in a longitudinal direction relative to the hub28. The cannula adapter32may be integrally formed with, or otherwise fixed to, the access cannula18, or the cannula handle30, or may be releasably attached to the access cannula18or cannula handle30. Axially fixing the hub28relative to the access cannula18, which is fixed relative to the vertebra10, minimizes the potential for disruption of the deformable conduit24while the clinician performs other steps, such as retraction or withdrawal of the steerable instrument22, or delivering an implant or treatment through the deformable conduit24. Referring toFIGS.3-6, the cannula adapter32comprises a body33and lock ring34rotatable relative to the body33. Referring back toFIG.1, the lock ring34is actuated by a clinician to lock the hub28axially in place with respect to the access cannula18, while allowing the hub28to rotate relative to the access cannula18. This allows the clinician to adjust the planar orientation of the steering instrument20while remaining axially locked in place. The lock ring34is configured to urge the cannula adapter32to engage a grooved section of the hub28. The grooved section of the hub28may comprise one or more spaced grooves35. Referring toFIGS.5and6, in one embodiment, the lock ring34comprises at least one locking ramp38. The lock ring34also may comprise one or more ring tabs40, for being engaged by a clinician to rotate the lock ring34. As the lock ring34is rotated by the clinician, the locking ramp38engages one or more cantilever arms42of the body33, moving the cantilever arms42inwards towards the center of the lock ring34. As the lock ring34is in a fully rotated position (seeFIG.6), at least one locking surface36of the cantilever arms42engages one of the spaced grooves35in the grooved section of the hub28, to prevent axial movement of the hub28relative to the access cannula18. The cantilever arms42may comprise at least one cantilever tooth44possessing the locking surface36dimensioned to engage one or more of the spaced grooves35among the plurality of axially spaced grooves35located on the grooved section of the hub28. The lock ring34may be configured to lock after rotation of less than 90, less than 60, less than 45, or less than 30, degrees of rotation relative to the access cannula18. In one embodiment, the lock ring34may comprise a recess that interacts with a stop member disposed on the cannula adapter32. After locking, the stop member may protrude into the recess of the lock ring34and prevent the lock ring34from rotating more than a predetermined amount in either direction. During operation, as the clinician rotates the lock ring34to axially lock the access cannula18to the hub28, the stop member eventually engages a surface forming the recess and prevents the clinician from rotating the lock ring34any further. Similarly, as the clinician reversibly rotates the lock ring34to release the hub28, the stop member eventually engages an opposing surface forming the recess and prevents the clinician from rotating the lock ring34any further. Alternative stop mechanisms are also contemplated which function to prevent over-rotation of the lock ring34relative to the cannula adapter32. Referring again toFIG.1, the system also comprises the steerable instrument22. The steerable instrument22has a length sufficient to extend beyond the distal end25of the deformable conduit24and the distal end21of the access cannula18. The steerable instrument22also has a diameter sufficient to be slidably disposed in a lumen of the deformable conduit24. Referring toFIGS.7,7A, and8, the steerable instrument22comprises a deflectable portion48capable of assuming at least a substantially straight configuration and a curved configuration. The steerable instrument22is actuated to assume the curved configuration when the deflectable portion48protrudes from the distal end21of the access cannula18. A distal end23of the steerable instrument22may be aligned with the distal end25of the deformable conduit24, or may protrude beyond the distal end25of the deformable conduit24. In some embodiments, the distal end23of the steerable instrument22extends beyond the distal end25of the deformable conduit24by at least 0.1, 0.5, 1, or 2, mm. The substantially straight configuration of the deflectable portion48is substantially coaxial with the longitudinal axis A of the access cannula18when the steerable instrument22is at least partially disposed within the access cannula18. The phrase “substantially straight” refers to those configurations of the deflectable portion48where the distal end23of the steerable instrument is angled away from the longitudinal axis A of the access cannula18at an angle of curvature B of less than 15, 10, 5, 3, or 1, degrees. Referring toFIGS.7and8, the curved configuration of the steerable instrument22results in the distal end23of the deflectable portion48of the steerable instrument22being radially offset from the longitudinal axis A of the access cannula18. The distal end23of the deflectable portion48may be deflected through angles of curvature B ranging from about 10 degrees to 25, 35, 60, 90, 120, or 150, degrees, or more, relative to the longitudinal axis A of the access cannula18. InFIG.8, the distal end23of the deflectable portion48is shown deflected by an angle of curvature B of approximately 90 degrees relative to the longitudinal axis A of the access cannula18. In other words, the steerable instrument22is actuatable and capable of assuming the substantially straight configuration, a fully actuated curved position, and any desired position in between. In some embodiments, the deflectable portion48may be actuated into a plurality of different predetermined radially offset positions with each of the plurality of different predetermined radially offset positions having an angle of curvature B, based on the angle the distal end23of the steerable instrument22extends from the longitudinal axis A of the access cannula18. In one embodiment, the deflectable portion48may be capable of curving in a single plane of motion. Alternatively, the deflectable portion48may be capable of curving in multiple planes of motion. When the steerable instrument22is actuated, the angle of curvature B of the distal end23of the deflectable portion48may be gradually manipulated until the desired angle of curvature B is achieved. In other words, the deflectable portion48of the single steerable instrument22is capable of assuming a variety of different angles of curvature B, based on the extent of actuation of the steerable instrument22. Furthermore, the radius of curvature can be determined by extending the deformable conduit24and/or the steerable instrument22through the distal end21of the access cannula to a greater degree with respect to one another. Alternatively, the steerable instrument22may be pre-tensioned such that upon emergence from the distal end21of the access cannula18, the deflectable portion48immediately assumes the angle of curvature B associated with the extent of pre-tensioning. The angle of curvature B of the deflectable portion48can be observed fluoroscopically, and/or by printed or other indicia associated with the steerable instrument22. The deformable conduit24may further include indicia visible under intraoperative imaging to assist in visualizing the deformable conduit24during placement. Such indicia may include radiopaque elements, such as metal reinforcement, filler material (e.g., barium sulfate) in the polymeric components, and/or one or more radiopaque markers (not shown). The curvature of the deflectable portion48allows the distal end23of the steerable instrument22to contact tissue which is radially offset from the longitudinal axis A of the access cannula18. Referring again toFIG.7, the steerable instrument22may comprise a tip50located on the distal end23of the deflectable portion48. The tip50may be sharp, rounded, or blunt. The tip50may optionally include a port52which allows the implant, such as a hardenable material, to be injected into hard tissue through the steerable instrument22. Alternatively, the tip50may be occluded such that no material can pass therethrough. Referring toFIG.7A, the steerable instrument22includes a control element54. The deflectable portion48is operatively connected to the control element54. In the embodiment shown, the distal end55of the control element54is connected to the deflectable portion48. The deflection of the deflectable portion48of the steerable instrument22is accomplished by exerting tension on the control element54, or by moving the control element54in a longitudinal direction along a control axis C of the steerable instrument22. In one embodiment, as the steerable instrument22is actuated, the control element54is moved along the control axis C to control the angle of curvature B of the deflectable portion48. Referring toFIG.8, in one embodiment, the control element54operates in a plurality of tension modes including an operating tension mode that enables the deflectable portion48to place the deformable conduit24in the deformed position and a slack tension mode to allow withdrawal of the deflectable portion48of the steerable instrument22from the deformable conduit24without substantially displacing the deformed position of the deformable conduit24once deformation is complete. The phrase “substantially displacing” is intended to refer to displacement of the distal end25of the deformable conduit24, after the deformable conduit24maintains the deformed position, of more than 0, more than 0.1, more than 0.3, more than 0.5, more than 0.75, more than 1, or more than 3, cm, in a lateral direction relative to the position of the distal end25of the deformable conduit24before retraction. In the operating tension mode, at least some tension is placed on the control element54such that the deflectable portion48is prevented from returning to a non-actuated position (e.g., straight). Although tension is mentioned, it will be understood that a plurality of actuation modes could also be referenced, such as a positively actuated mode and a non-actuated mode for embodiments where tension is not used to actuate the steerable instrument22. If the steerable instrument22is disposed outside the lumen of the deformable conduit24and the control element54is in the slack tension mode, the steerable instrument22assumes a substantially straight configuration. The slack tension mode allows the deflectable portion48to move freely, which allows easy retraction of the steerable instrument22through the deformable conduit24. In the slack tension mode, the steerable instrument22exerts substantially zero lateral force on the deformable conduit24as the steerable instrument22is withdrawn from the deformable conduit24. This allows the steerable instrument22to be slidably removed from the deformable conduit24after the deformable conduit24is in the deformed position relative to the longitudinal axis A of the access cannula18. In other words, when the steerable instrument22is operated in a slack tension mode, the deflectable portion48of the steerable instrument22becomes limp and exerts substantially no lateral force in any direction and is adapted to readily conform to the deformed position of the deformable conduit24without causing the deformable conduit24to be substantially displaced from the deformed position. This feature allows the deformable conduit24to maintain its position in softer tissues, such as osteoporotic bone, or tissues outside of bone. In some embodiments, the control element54may comprise one or more wires, bands, rods, or cables, which are attached to the deflectable portion48. The control elements54may be spaced axially apart along the length of the deflectable portion48to allow the distal end23of steerable instrument22to move through compound bending curves. In the embodiment shown, the control element54is a single cable or wire attached to the deflectable portion48. The distal end of the control element54may be fastened to the distal end23of the deflectable portion48by welding, crimping, soldering, brazing, or other fastening technology. Referring again toFIG.8, the steerable instrument22may further comprise a steering handle56, and/or a control surface58. The steering handle56may allow the clinician to rotate the steerable instrument22relative to the access cannula18or the deformable conduit24. The proximal end57of the control element54may be disposed in the steering handle56. In one possible configuration, the control surface58may be at least partially disposed within the steering handle56. The control surface58is operatively connected to the control element54. Therefore, the control surface58may be manipulated by the clinician to cause the deflectable portion48of the steerable instrument22to occupy a position radially offset from the longitudinal axis A of the access cannula18and to assume a desired angle of curvature B. In other words, actuation of the control surface58may cause the deflectable portion48of the steerable instrument22to move away from the longitudinal axis A of the access cannula18. In certain exemplary embodiments, actuating the steerable instrument22comprises manually engaging the control surface58, to control the angle of curvature B of the deflectable portion48. However, the control surface58may also be engaged using mechanized, electric, or automated devices. The control surface58may allow for continuous and positive adjustment of the angle of curvature B of the deflectable portion48throughout the entire range of possible angles of curvature B. In other embodiments, the control surface58may be configured for stepwise adjustment of the curvature of the deflectable portion48, to the plurality of possible angles of curvature B via a ratchet assembly68. Alternatively, the control surface58may be configured to place the control element54in one or more of the plurality of tension modes described above. The control surface58may comprise a thumbwheel, slider, button, trigger, rotatable knob, or combinations thereof, and may be actuated by rotating, pulling, sliding, squeezing, or pushing the control surface58. The control surface58may be configured to allow for one-handed operation by a clinician. Referring toFIG.7A, the steerable instrument22further comprises a shaft60having a distal end51and a proximal end53. The control element54resides within a lumen of the shaft60, or may be provided external to the shaft60. The proximal end53of the shaft60is may be disposed within the steering handle56. The proximal end53of the shaft60is engaged by a mounting block62fixed to the steering handle56that maintains alignment of the shaft60within the steering handle56. The proximal end53of the shaft60is fixed to the mounting block62. In certain embodiments, the control element54passes through the shaft60and the proximal end of the control element54is operatively coupled to the control surface58. In the embodiment shown, the steering handle56further comprises a guide cylinder64having a hole disposed there through. The control element54passes through the hole in the guide cylinder64. The proximal end57of the control element54is engaged by a crimp sleeve, weld, adhesive, or other fastening method to prevent the proximal end57of the control element54from being pulled back through the hole in the guide cylinder64during operation. A flexible member, such as a spring may be positioned to operably interact with both the control surface58and the control element54to control or limit the amount of force that the control surface58is able to apply to the control element54. The steering handle56defines a void66. The guide cylinder64is slidably disposed in the void66to guide the guide cylinder64such that the guide cylinder64may move freely in a linear direction along the control axis C, substantially aligned with the shaft60but may not move transversely relative to the shaft60of the steerable instrument22. In one specific embodiment, the control surface58is presented by a trigger59, and the trigger59has a rear surface that engages the guide cylinder64as the trigger59pivots about the pivot P, which during actuation, induces tension in the control element54. The trigger59may be biased towards the slack tension mode by virtue of a trigger spring (not shown) or other device operable to bias the trigger in the non-actuated position. In certain embodiments, the control surface58is configured to apply force to the control element in only one direction of actuation. This allows the control surface58(and the control element54) to return to a rest position while remaining in slack mode, and prevents forces from other elements, such as springs, gravity, and inadvertent movement of the control surface58, from affecting the position of the deformable conduit24. The ratchet assembly68interacts with the trigger59to selectively retain the deflectable portion48in one of the plurality of tension modes or angles of curvature B. Alternatively, or in addition to the ratchet assembly68being operatively connected to the control element54, the ratchet assembly68may be operatively connected to the control surface58. The ratchet assembly68may be selectively disengaged by touching a release button69or other device, such that the control element54may move freely between a non-actuated and an actuated position. The ratchet assembly68may be disposed at least partially within the steering handle56. The ratchet assembly68may comprise a pawl70disposed within the steering handle56and a ratcheting member72. The ratcheting member72may comprise a plurality of teeth that are capable of being engaged by the pawl70. The pawl70may include one or more teeth which correspond to the teeth of the ratcheting member72. The ratchet assembly68may further comprise a mount to orient the ratcheting member72or pawl70such that engagement of the ratchet assembly68places the pawl70into operative position with respect to the ratcheting member72. In such embodiments, when the control element54is being actuated, the pawl70slides up over the edges of the trigger teeth of the ratcheting member72. When the control element54is no longer being actuated, the pawl70will engage one of the plurality of teeth of the ratcheting member72and prevent the control element54from returning to the non-actuated configuration until released by pressing release button69. Other configurations of the ratchet assembly68that are sufficient to selectively retain the deflectable portion48in one of the plurality of tension modes or curvature positions are also contemplated, such as a friction-based mechanism that selective retains the control element54in one of a plurality of frictionally engaged positions. Referring toFIGS.9-15, in one or more embodiments, the deflectable portion48of the steerable instrument22comprises a plurality of movable segments collectively capable of assuming at least the substantially straight configuration and the curved configuration. The size, shape, and/or spacing of the movable segments may affect the radius, angle of curvature, and/or limits of deflection for the deflectable portion48of the steerable instrument22. The plurality of movable segments may comprise a plurality of interlocking and individual links74. The phrase “individual links” refers to distinct and discrete members. The plurality of individual links74allow the steerable instrument22to possess the slack mode, which enables withdrawal and retraction of the steering instrument22without substantially displacing the deformable conduit24from the deformed position. Furthermore, the individual links74, shaft60and/or control element54are capable of being actuated with less than 3, 2.5, 2, 1.5, 1, or 0.5% strain, which allows the steerable instrument22to be actuated multiple times without inducing fatigue of the individual links74and premature failure. Furthermore, the plurality of individual links74may be actuated to a fully-actuated position without any of the plurality of individual links74, the control element54, or the shaft60undergoing permanent deformation. Referring toFIGS.9-13, the plurality of individual links74comprises at least one first link76and at least one second link78. The distal end of the first link76engages a proximal end of the second link76. Referring toFIG.9, a plurality of the first links76and a plurality of the second links78may be included to form the deflectable portion48. In the embodiment shown, the first and second links76,78are identical in configuration. In the substantially straight configuration, each link of the deflectable portion48is substantially co-axial with the adjacent link. In the embodiment shown, a distal link77is provided to form the distal end23of the deflectable portion48and the shaft60is configured to receive one of the links76,78. Each of the plurality of links74may be hollow to allow the control element54to pass therethrough. The distal end55of the control element54may be welded or otherwise fastened on an interior surface of the distal link77, or another link adjacent thereto. The actuation of the control element54may urge the distal link77in a proximal direction, which results in the curvature of the deflectable portion48, and the articulation of the remaining links. In some embodiments, the control element54is only attached to the distal link77and is not attached to the remaining links. However, in other embodiments, the control element54may be attached to two or more of the plurality of links74. In the embodiments shown, nine links74,77are shown with each adding 10 degrees deflection from shaft axis S to provide an angle of curvature B of 90 degrees for the deflectable portion48. The angle of curvature B, as shown inFIG.10can be measured between a central shaft axis S of shaft60and a central distal axis D of distal link77. Referring toFIGS.10and13, the distal end of each of the link76,78comprises at least one slot80and the proximal end of each link76,78comprises at least one follower82. In the embodiment shown, each of links76,78have two slots80and two followers82. The followers82are configured to be movably disposed within the slots80of an adjacent link. The followers82and the slots80are arcuate in shape in some embodiments. The slots80may comprise an open-end and a closed end. In the actuated mode, the followers82of one link may touch the closed ends of the slots80of an adjacent link (SeeFIG.10). In the non-actuated mode, the followers82of one link may be spaced apart from the closed end of the slots80of the adjacent link (SeeFIG.9). As the steerable instrument22is actuated, the followers82follows the curve of the slots80until the end of the followers82contact the closed end of the slots80. In the embodiment shown, the shaft60includes two slots80at its distal end61. The followers82and slots80are configured such that longitudinally they are locked to one another. In other words, the followers82and the slots80, when constrained inside the deformable conduit24, provide for the links74being unable to be become disengaged from one another. Referring toFIG.12, the first link76may also comprise at least one protrusion84and the second link78may comprise at least one groove86, with the protrusions84sized to be movably disposed within the grooves86. Alternatively, the second link78may comprise the at least one protrusion84and the first link76comprise the at least one groove86. Referring toFIG.11, in the embodiment shown, the first and second links76,78include both the two protrusions84and the two grooves86alternating on opposing ends. The interaction of the protrusions84and the corresponding grooves86provides additional torsional and lateral strength to the deflectable portion48. The protrusions84of the deflectable portion48that faces in the direction of curvature may be spaced from an end surface forming the corresponding grooves86of the steerable instrument22when not actuated, and may directly contact the end surfaces forming the grooves86upon actuation. In one specific embodiment, the protrusions84and the grooves86may be configured in an interlocking shape, such as a trapezoid where the protrusions84are wider at the top of the protrusions and the grooves86is correspondingly wider at the bottom, which would add additional strength and stability to the plurality of links74. Referring toFIGS.9and10, in certain embodiments, the intersection of the first link76and the second link78defines a gap104there between. The first link76and/or the second link78may comprise an angled portion90that defines a fulcrum92of rotation between the first link76and the second link78. The angled portion90is arranged at an acute angle relative to end surface94. By configuring the fulcrum92to be substantially coaxial with the curved surfaces of the slot80and follower82, the plurality of links74maintain multiple points of contact with one another during actuation of the steerable instrument22, which allows the plurality of links74to bear a substantial axial load via end surfaces94while the steerable instrument22is axially advanced through tissue, while also allowing the deflectable portion48of the steerable instrument22to exert a substantial lateral force on the deformable conduit24when the steerable instrument22is actuated. This allows the system and method to operate in harder tissue, such as non-osteoporotic cancellous bone without experiencing permanent deformation or failure. The length and angle of the angled portion90may be controlled to adjust the position of the fulcrum92. The angled portion90may be angled at 10, 20, 30, 40, 50, 60, 70, or 80 degrees or more relative to the distal end surface94of the corresponding link. Referring toFIGS.14and15, an alternative deflectable portion48ais shown that may be capable of deforming in multiple directions with the movable segment comprising a plurality of multi-directional links94. In such an embodiment, each of the plurality of multi-directional links94typically comprises at least two actuation holes96. The control element may comprise wires or cables disposed within each of these actuation holes96, allowing the deflectable portion48ato be articulated in multiple directions. By tensioning the control element that passes through a first actuation hole96ato a greater degree than the control element that passes through a second actuation hole96b, the deflectable portion48aassumes a curved configuration in a particular direction. The multi-directional links94may further comprise the slots, followers, protrusions, and/or grooves described above. Alternatively, the multi-directional links may comprise a multi-directional fulcrum98. The multi-directional fulcrum98may be rounded, such that the adjacent links may freely rotate in any direction as the deflectable portion48ais actuated. Alternatively, the deflectable portion48may be uni-directional. Alternatively, a plurality of movable segments may comprise a plurality of hinge joints joined by a spine (not shown). The plurality of hinge joints assists in the reversible deflection of the deflectable portion of the steerable instrument. A hinged side of the deflectable portion shortens under compression, while the spine side of the deflectable portion retains its axial length, causing the deflectable portion to assume a relatively curved or deflected configuration as the control element is activated. The plurality of movable segments may be manufactured by laser cutting, electrical discharge machining, water jet cutting, or other suitable manufacturing method using a single metal tube using a pre-defined pattern, such that the tube is pre-assembled. The steerable instrument may comprise Nitinol, stainless steel, or other suitable metal alloy. In another embodiment, the steerable instrument22does not allow a material to pass there through, and can be configured to utilize larger and stronger components, which will result in a more robust tool that can easily displace cancellous bone. In the embodiment shown, the steerable instrument22comprises a control element54disposed in the lumen defined in part by shaft60and in part by the plurality of links74, or movable segments. In one embodiment, the cross-sectional area of the lumen may be completely filled by the presence of the control element54. Alternatively, at least 25%, 40%, 55%, 65%, 75%, 85%, or 95% of the cross-sectional area of the lumen of the steerable instrument22may be occupied by the control element54. In the embodiment shown, the control element54substantially fills the lumen of the steerable instrument22. Depending on the proportion of the lumen occupied by the control element54, the lumen may function to allow the passage of the implant therethrough. Furthermore, the strength of the steerable instrument22may depend on the proportion of the lumen occupied by the control element54. Referring toFIGS.16-18, the deformable conduit24defines a lumen dimensioned to allow the steerable instrument22to be slid through the deformable conduit24. Referring toFIG.1, the deformable conduit24is configured to retain the shape of the steerable instrument22when the steerable instrument22assumes the curved configuration and hence, the distal end25of the deformable conduit24is positioned at the desired location in the tissue. The deformable conduit24is sized for insertion within the lumen of the access cannula18and includes a proximal end27and the distal end25. The deformable conduit24is dimensioned to have a sufficient length to extend through and be operable beyond the distal end21of the access cannula18. The deformable conduit24may be employed to deliver hardenable material to the target site. Thus, the deformable conduit24has an outer diameter that is smaller than a diameter of the lumen of the access cannula18; however, the outer diameter of deformable conduit24preferably will not be so small as to allow hardenable material to readily travel around the outside of the deformable conduit24and back into the access cannula18. In certain embodiments, an inner lumen diameter of the deformable conduit24may be preferably optimized to allow a minimal exterior delivery pressure profile while maximizing the amount of hardenable material that can be delivered, such as bone cement. In one embodiment, the percentage of the lumen diameter with respect to the outside diameter of the deformable conduit24is at least about 60%, 65%, 70%, 75%, 80%, 85%, 95% or more. The deformable conduit24may include depth markings (not shown) along a proximal section that facilitates desired locating of the distal end25of the deformable conduit24relative to the distal end21of the access cannula18during use. The deformable conduit24or the steerable instrument22may also include indicia (not shown) that show the direction of the curvature. Referring toFIGS.16and17, the hub28partially surrounds the deformable conduit24and is slidably coupled to the proximal end27of the deformable conduit24. The hub28comprises a proximal hub connector100, and a distal hub connector102. The hub defines a central passage99. The deformable conduit24is slidably disposed within the central passage99of the hub28such that the deformable conduit24can move in an axial direction relative to the hub28. The hub28may comprise a polymeric material, such as ABS, nylon, polyether block amides, or other thermoplastic. Referring toFIG.17, the proximal hub connector100of the hub28is configured to connect to the steerable instrument22, an expandable member, an implant delivery system, cavity creation tool, or other device. The proximal hub connector100may utilize a detent system to ensure that the hub28is axially fixed and rotationally fixed to the steerable instrument, expandable member, implant delivery system, etc. In such an embodiment, the proximal hub connector100may include one or more latches104with detent fingers (not numbered) extending proximally from the proximal hub connector100which are configured to releasably engage a notch106, void, groove, or other connector of the steerable instrument, expandable member, or implant delivery system so that the hub28is axially and rotationally fixed to the steerable instrument, expandable member, etc. The distal end of the latch104may function as a lever107, such that pressing the distal portion of the latch104towards the hub28results in the release of the detent system (the proximal end of the latch104is urged outward, thus releasing from the notch106of the corresponding component). It is also contemplated that the latch104and notch106could be replaced with other retention systems that are capable of fixing the hub axially and rotationally to the steerable instrument. Referring toFIG.18, the hub28is configured to connect to the access cannula18via the distal hub connector102. The distal end29of hub28has an opening (not numbered) through which the deformable conduit24slides during operation. In some embodiments, the distal hub connector102is configured to connect to the cannula adapter32. The distal hub connector102includes the grooved section of hub28previously described. The distal hub connector102interacts with the cannula adapter32to form an axial locking mechanism. In one specific embodiment previously described, the grooved section of the distal hub connector102interacts with the lock ring34to lock the hub28and cantilever arms42of body33axially in place with respect to the access cannula18, while allowing the hub28, and the deformable conduit24, to rotate relative to the access cannula18. As described above, the grooved section of the distal hub connector102may comprise one or more spaced grooves35spaced to correspond to a specific predetermined depth of the deformable conduit24relative to access cannula18depending on which spaced groove35is engaged by the cannula adapter32. In another embodiment (not shown), the hub28may interact with the access cannula18in a manner that is not rigidly fixed. In such an alternative, the hub28employs axial force resulting from the flexure of a component or friction to resist relative movement of the access cannula18relative to the hub28. This axial force may be provided from frictional forces arising from moving parts, or from interaction of one component with an elastomeric member, such as o-ring. Referring again toFIG.16, the deformable conduit assembly26may comprise an axial controller110configured to urge the deformable conduit24in the axial direction relative to the hub28, within the distal end opening of the hub28and the access cannula18, without moving the access cannula18or the hub28in the axial direction. The axial controller110comprises a conduit control surface114operatively connected to the deformable conduit24. In such an embodiment, the hub28may comprise one or more guiding slots112that allow the conduit control surface114to be disposed there through. The conduit control surface114may be engaged to urge the deformable conduit24in a proximal or a distal direction relative to the hub28. This may allow the clinician to expose the expandable structure128without disturbing the expandable member126. The function may also be useful for urging the expandable structure128back into the deformable conduit24prior to withdrawal of the expandable structure128after use. In the embodiment shown inFIG.18, the axial controller110includes a control body111fixed to the proximal end27of the deformable conduit24. The control body111has a diameter smaller than the passage99of the hub28such that the control body111may be slidably disposed in the hub28. The control body111may comprise a tube concentrically fixed on the outer circumference of the deformable conduit24. The control body111may be coaxially positioned within the passage99of the hub28. The axial controller110comprises one or more arms113extending from the control body111. The arms113may be dimensioned and oriented to protrude though the guiding slots112. Each of slots112has a closed end that acts as a stop for the arms113to limit the amount of distal movement of the deformable conduit24. The arms113present the conduit control surfaces114. Alternative conduit control surfaces114are also contemplated, such as threaded surfaces, a helical slot and follower, or rack and pinion device. In one example, a clinician may urge the conduit control surface114axially to urge the deformable conduit24axially, such that the axial position of the deformable conduit24changes relative to the access cannula18and relative to the hub28. In another example, indicia (visible, tactile, or audible) may be provided with the deformable conduit24or expandable structure128to allow the clinician to set a precise amount of desired exposure of the expandable structure128, thus allowing the deformable conduit24to affect the proportion of the expandable structure128that contacts tissue. The axial controller110may also function to guide the deformable conduit24such that the deformable conduit24does not rotate relative to the hub28of the deformable conduit assembly26. In one specific embodiment, this guiding function may be accomplished by positioning the conduit control surfaces114within the one or more guiding slots112of the hub28such that the conduit control surfaces114are constrained rotationally relative to the hub28, and therefore prevent the deformable conduit24from rotating relative to the hub28. The arms113may simultaneously prevent the hub28from rotating relative to the deformable conduit24. Thus, the rotational arrangement of the hub28and the deformable conduit24may be rotationally fixed to one another. Alternatively, or in addition to such an embodiment, the control body111may comprise an alignment feature116which ensures that the control body111does not rotate in the passage99relative to the hub28. The alignment feature116may comprise a protrusion sized to slide within a channel118disposed in the hub28. The protrusion116and the channel118may be complementarily dimensioned such that the protrusion116may slide longitudinally within the channel118as the deformable conduit24moves relative to the hub28. In other embodiments, the hub28is not employed and the deformable conduit24is deployable in the access cannula18. In these embodiments, a handle may be fixed to the deformable conduit24. The deformable conduit24may be moved relative to the access cannula18to control the placement of the distal end25of the deformable conduit24. Referring toFIGS.19and20, in certain embodiments, the deformable conduit24may be a multi-layer, internally-reinforced, tube. This allows the deformable conduit24to potentially possess a combination of attributes; including high hoop strength to resist internal pressure, high axial strength for pushability, and a low lateral stiffness to allow the deformable conduit24to maintain the deformed position in softer tissues. In the embodiment shown, the deformable conduit24comprises a reinforcement120, a liner122, and/or a sheath124. However, it is also contemplated that the multi-layer tube may include 2, 4, 5, 6, or more layers. The reinforcement120typically comprises a braid, a coil, weave, or one or more longitudinal strands of reinforcing material. The reinforcing material may possess a circular, flattened rectangular, or oval cross-section, in order to optimize strength and stiffness properties while minimizing radial thickness. The reinforcing material typically comprises metal, fabric, plastic, fiberglass or alternative materials that have minimal elasticity upon deformation. In one specific embodiment, the reinforcement120comprises a braid comprising stainless steel. The liner122may comprise a lubricious polymer. The lubricious polymer is a material that allows components such as the steerable instrument22to easily slide adjacent to the liner122. The liner122is typically inert and biologically compatible. In exemplary embodiments, the inner liner122comprises a fluoropolymer, PEBA, nylon, or combinations thereof. The inner liner122may be coated with a lubricant or coating to enhance lubricity, abrasion resistance, or another desired property. The sheath124may comprise a polymer that is capable of resisting abrasion while contacting hard tissue or the access cannula18and is sufficiently strong to traverse hard tissue, such as bone. For example, the sheath124may comprise a thermoplastic elastomer, such as a polyether block amides or nylon. The reinforcement120, the liner122, and the sheath124may be distinct layers. Referring toFIG.19, the reinforcement120, the liner122, and the sheath124, may be concentrically arranged, with each element forming a distinct layer of the deformable conduit24. Alternatively, the reinforcement120may be at least partially embedded in the liner122, the sheath124, or both the liner122and the sheath124. Alternatively still, the reinforcement120may be completely embedded in single polymeric tube, with no other layers being present. Referring toFIG.20, the density of the reinforcement120may vary along the longitudinal dimension of the deformable conduit24. For example, a distal portion of the deformable conduit24may include less of the reinforcement material per centimeter than a proximal portion to allow for improved flexibility of the distal portion of the deformable conduit24or improved pushability of the proximal portion of deformable conduit24. Alternatively, the amount of the reinforcement material in the deformable conduit24at the distal portion may be equal to, or less than the density of the reinforcement material at the proximal portion. It is also contemplated that the reinforcement120may not extend the entire length of the deformable conduit24; rather, the reinforcement120may be provided in less than 90, 75, 50, or 25% of the length of the deformable conduit24. Referring toFIGS.21-23, in certain embodiments, the system further comprises an expandable member126. The expandable member126may comprise an expandable structure128, such as a balloon, stent, flexible bands (such as metal bands) or other device capable of increasing in size in the radial direction. In certain embodiments, the expandable structure128is capable of expanding to a diameter to a size larger than the diameter of the deformable conduit24. The expandable member126is typically biocompatible and dimensioned and configured to be inserted through the deformable conduit24in the deformed position. The expandable member126may further comprise one or more components appropriate for forming a cavity or void within tissue. Alternative to the expandable member, the system may employ an alternative cavity creation tool that does not expand to create the cavity. In some constructions, the expandable member126may include one or more inflatable members (e.g., a single balloon, multiple balloons, a single balloon with two or more discernable inflation zones) constructed to transition between a contracted state in which the inflatable member may be passed through the lumen of the deformable conduit24or the access cannula18, and an expanded state in which the inflatable member expands and displaces cancellous bone16or other tissue. Referring toFIG.21, in the illustrated embodiment, the expandable member126typically includes an inner catheter tube134having a distal end135. The inner catheter tube134may comprise vinyl, nylon, polyethylenes, ionomer, polyurethane, and polyethylene tetra phthalate (PET). The inner catheter tube134may further comprise one or more rigid materials to impart greater stiffness and thereby aid in its manipulation, such as stainless steel, nickel-titanium alloys (Nitinol™ material), and other metal alloys. The inner catheter tube134may include multiple holes to allow inflation fluid to pass from the proximal end of the expandable member126, through the inner catheter tube134, in order to inflate the expandable structure128. The expandable member126may further comprise an outer catheter tube136. The outer catheter tube136may comprise multiple layers, or multiple concentric tubes. The inner layer of the outer catheter tube136may comprise a relatively stiff polymer for pressure resistance, and the outer layer of the outer catheter tube136may comprise a relatively soft polymer that allows for adhesion between the outer layer and the expandable structure128. The distal end of the outer catheter tube136may abut the proximal end of the expandable structure128. The outer catheter tube136may be partially disposed within the expandable structure128, with the outer layer of the catheter tube136bonded to the proximal end of the expandable structure128. In some embodiments, at least a portion of the inner catheter tube134may be configured with relief features to allow the inner catheter tube134to bend freely to allow for advancement through the deformable conduit24while minimizing undesired movement of the deformable conduit24. The relief features may comprise grooves, thinned areas, or a helical spiral cut through the inner catheter tube134. In the embodiment shown, the inner catheter tube134comprises a helical spiral cut. The helical spiral cut may improve the pushability of the expandable member126by acting as a spring compressed to solid height. For embodiments where the inner catheter tube134is spirally cut, the pitch of the spiral cut may vary along the longitudinal dimension of the inner catheter tube134. For example, the distal portion of the inner catheter tube134may have a greater concentration of cuts per centimeter than the proximal portion to allow for improved flexibility of the distal portion of the inner catheter tube134relative to the proximal portion. Alternatively, the proximal portion of the inner catheter tube134may have a lesser concentration of cuts per centimeter to allow for improved stiffness and pushability of the proximal portion of the expandable member126. The spiral cut may be pitched at a ratio ranging from 0.1 to 10 rotations per centimeter of the inner catheter tube134depending on the desired stiffness of the inner catheter tube134. Alternatively, the spiral cut may be pitched at a ratio ranging from 0.5 to 8, or 1 to 3, rotations per centimeter of the inner catheter tube134. It is also contemplated that the outer catheter tube136may comprise one or more relief structures in a manner similar to the inner catheter tube134described above. In certain embodiments, the expandable member126may comprise a stylet138. The stylet138can be flexible or rigid, and may comprise a plastic, or metal material. The stylet138may be dimensioned and configured to slide in a lumen of the inner catheter tube134, or in the gap between outer catheter tube136and inner catheter tube134. The stylet138may include a threaded coupling to secure the stylet138to the expandable structure128to prevent movement of the stylet138during deployment of the expandable structure128. The presence of the stylet138provides axial strength as the expandable structure128is urged through the access cannula18or the deformable conduit24. Once the expandable structure128is free of the deformable conduit24(or the access cannula18) and is disposed within tissue, the stylet138can be withdrawn. The lumen of the inner catheter tube134(or the gap between outer catheter tube136and inner catheter tube134) can serve as a pathway for inflating the expandable member126, introducing rinsing liquid, to aspirate debris from the tissue, or to introduce hardenable material, such as bone cement. The inner catheter tube134may contain at least one opening in fluid communication with the inner volume of the expandable structure128. Alternatively, the inner catheter tube134or the gap between inner catheter tube134and outer catheter tube136may contain at least one opening in fluid communication with the tissue being treated. In one specific embodiment, the inner catheter tube134may be disjoined from the outer catheter tube136and slidably disposed on the stylet138, such that during expansion of the expandable structure128, the inner catheter tube134is urged distally from outer catheter tube136. The inner catheter tube134may be configured to exert no axial force on expandable structure128. Alternatively, the inner catheter tube134may be configured to exert an axial force on the expandable structure128to affect the expanded shape. In certain embodiments, an object or device may be inserted into inner catheter tube134to allow the clinician to apply force to expandable member128. This device may comprise the stylet138configured in a pre-formed shape to allow directional control of the expandable member126. Alternatively, a device similar to the steering instrument22, but having different dimensions, may be inserted into inner catheter tube134for further control of the expandable member126. As an alternative to the inner catheter tube134, a solid member may be utilized (not shown). In such an embodiment, the gap between the solid member and the outer catheter tube136may allow fluid to enter and expand the expandable structure. The solid member may comprise one or more of medical alloys and polymeric materials described above. The solid member may comprise one of more of the relief features described above with respect to the inner catheter tube. The expandable structure128may comprise a plurality of shapes, such as an hour-glass, spherical, elliptical, rectangular, pyramidal, egg-shaped, or kidney-shaped. In certain embodiments, the size and shape of the expandable structure128may be restrained with one or more additional components, such as internal and/or external restraints. In preferred embodiments the expandable structure128will be structurally robust, able to withstand (e.g., not burst) expected inflation pressures when in contact with tissue. The expandable member126may further comprise one or more additional components connected or operable through the proximal region for actuating the corresponding expandable member126, such as an inflator. In another embodiment, the expandable member126may include a plurality of expandable structures128. The number of expandable structures128utilized in the procedure may be controlled by utilizing separate actuation passages (e.g. lumens) or members within in the expandable member126, or by using the deformable conduit24to expose only the desired number of expandable structures to the tissue. Indicia (visible, tactile, or audible) may be provided to indicate the number of expandable structures128. Referring toFIGS.22and23, the expandable member126may comprise a housing130, having one or more detent features, such as notches, such that the housing130of the expandable member126can be axially fixed relative to the access cannula18and so that the position of the expandable structure128does not move relative to the access cannula18. This connection be accomplished using the latches104similar to the connection of the steering instrument22to the hub28. This serves to prevent inadvertent axial movement of the expandable member126that may occur during retraction of the deformable conduit24or actuation of the expandable member126. In one embodiment, the housing130of the expandable member126is configured to connect to the hub28of the deformable conduit assembly26. The hub28may fixedly engage the housing130or some other portion of the expandable member126, to axially fix the position of the expandable structure128relative to the position of the access cannula18, such that the deformable conduit24may move axially relative to the access cannula18without moving the expandable member126, including not moving the expandable structure128. The housing130may have features to facilitate gripping and maneuvering of the expandable member126. Finally, the housing130may include features for attachment to another instrument, such as an inflator. In one preferred embodiment, the expandable member126is dimensioned to extend through the deformable conduit24such that the distal end127of the expandable member126, upon insertion into the deformable conduit24, does not protrude beyond the distal end25of the deformable conduit24when the deformable conduit24is fully deployed. In this configuration, the expandable structure128stays within the lumen of the deformable conduit24until the deformable conduit24is retracted. This facilitates easier and more accurate introduction of the expandable member126into the desired location by not requiring the expandable member126to displace tissue during deployment, and may protect the expandable structure128from external damage during introductory movement into tissue. The access cannula18, steerable instrument22, deformable conduit24, and/or the expandable member126may include one or more visual indicia (e.g., markings on the clinician-held end, radio-opaque indicia at or near the distal end), tactile indicia (e.g. change in axial force felt by the clinician), or audible indicia (e.g. clicking sounds) that enable a clinician to determine the relative positions of those components to perform the methods described below. Referring toFIG.24, the system may further comprise an implant140and an implant delivery system142. The implant140may comprise a biocompatible material that is configured to remain adjacent to tissue permanently, semi-permanently, or temporarily. The implant140may comprise a hardenable material, bag, sheath, stent, and/or any combination thereof. The phrase “hardenable material” is intended to refer to materials (e.g., composites, polymers, and the like) that have a fluid or flowable state or phase and a hardened, solid or cured state or phase. Hardenable materials may include, but are not limited to, injectable bone cements (such as polymethylmethacrylate (PMMA) bone curable material), which have a flowable state wherein they may be delivered (e.g., injected) by a cannula to a site and subsequently cure into hardened, cured material. Other materials such as calcium phosphates, bone in-growth materials, antibiotics, proteins, etc., may be used in place of, or to augment the hardenable material. Mixtures of different hardenable materials may also be used. The implant delivery system142may assume various forms appropriate for delivering the desired implant140(e.g., for delivering the hardenable material or other implant type). In certain embodiments, the implant delivery system142may comprise a chamber filled with a volume of hardenable material and any suitable injection system or pumping mechanism to transmit the hardenable material out of the chamber and through the deformable conduit24. Alternatively, the implant delivery system142may comprise a hand injection system where a clinician applies force by hand to a syringe. The force is then translated into pressure on the hardenable material which causes the hardenable material to flow out of the syringe. A motorized system may also be used to apply force. A nozzle may be connected to the implant delivery system142. The nozzle may comprise a tube configured for coaxial insertion into the deformable conduit24, thus allowing delivery of material through the deformable conduit24without contacting the inner walls of the deformable conduit24. The implant delivery system142may connect to the deformable conduit24such that the implant140may be delivered through the lumen of the deformable conduit24to the target site. The implant delivery system142may connect to the proximal end of the hub28such that the deformable conduit24can be gradually or immediately retracted during the step of placing the implant140. This locking can be accomplished using the latches104of the hub28to engage one or more notches located on the implant delivery system, similar to the notches of the expandable member126. Another embodiment may include an adapter configured to allow attachment of a cement cannula (e.g., a rigid tube configured to be filled with hardenable material) to the deformable conduit24, thus allowing the clinician to urge material through the deformable conduit24by using an instrument to displace material from the cement cannula. In yet another embodiment, the system may comprise an aspiration device. The aspiration device functions to extract unwanted tissue, marrow products (blood precursors and marrow fat) that get displaced during performance of the described method. The system may be configured for aspiration from a lumen or gap within or between parts (e.g. a lumen within the expandable member126or deformable conduit24, from the gap between the expandable member126and the deformable conduit24, or from the gap between the deformable conduit24and the access cannula18). The aspiration device may comprise a suction port and a seal that allows passage of instruments while preventing escape of fluids (i.e. a hemostasis valve) that attaches to or is integral to the access cannula18or the deformable conduit24. The hemostasis valve may also connect to a suction tube. The hemostasis valve may be connected to a vacuum pump or a vacuum-generating syringe, and may have a check valve a fluid/tissue collection chamber. If performing a bi-pedicular procedure, the aspiration device could be used to aspirate on the contra lateral side which could influence the implant140to come across the midline. The aspiration device may be integrated with the implant delivery system142or may be used independently of the implant delivery system142. The aspiration device may be utilized in combination with the various devices and methods disclosed herein. This disclosure also relates to a surgical method for manipulating tissue. The method may comprise providing the access cannula18, the steerable assembly20, and the implant140. The steerable assembly20comprises the steerable instrument22and the deformable conduit24with the steerable instrument22removably disposed within the deformable conduit24. Referring again toFIG.1, the target site for manipulation may be identified by a clinician. Identification of the target site may include locating a pre-determined location within tissue for surgical intervention. In one embodiment, identifying the target site may comprise locating a central location in the cancellous bone16of the vertebra10that will support height-restoration and/or structural augmentation that preferably is at least generally symmetrical with respect to the vertebra10. Several distinct methods are described herein. Although they are described individually, it is to be appreciated that the steps may be interchangeable and may be substituted with one or more alternative steps. The following methods may be accomplished under either a local anesthetic or short-duration general anesthetic. The procedure is typically performed using intraoperative imaging such as fluoroscopy or CT. Once the area of the spine is anesthetized, an incision is made and a penetrating guide pin may be used to perforate the tissue and gain access to the target site. An expander may be slid over the guide pin to further retract tissue. The clinician slides the access cannula18over the expander and guide pin until the end surface of the access cannula18penetrates the vertebra10. The clinician then removes the guide pin and expander and inserts the drill to create a channel in the cortical bone14. The clinician can now remove the drill leaving only the access cannula18. In alternative embodiments, the guide pin and/or an expander are not used, but instead, the access cannula18is placed through the tissue with an access stylet coaxially locked to the access cannula. The access stylet has a sharp distal end to core into the cortical bone of the vertebra10. The access cannula18may have a similarly sharp distal end21to penetrate the vertebra10with the access stylet. Once the access cannula18is in place in the cancellous bone16, the access stylet is removed. Once the channel through the pedicle12and into the vertebra10is created, various methods may be used to stabilize the subject vertebra10. Referring toFIG.1, the method may further comprise directing the steerable assembly20through the access cannula18such that at least a portion of the steerable assembly20protrudes from the distal end21of the access cannula18into tissue at the target site. More specifically, the method may include positioning the steerable instrument22in the deformable conduit24until the latches106lock into the notches106in steerable instrument22and then sliding this steerable assembly20through the access cannula18to the target site. The fluoroscope imaging is continuously observed during insertion to verify placement of the deformable conduit24into the target tissue. If the steerable instrument22includes depth markings, the appropriate depth marking of the steerable instrument22will be aligned with the corresponding line on the access cannula18as additional confirmation that the distal end of the steerable instrument22is extended to the target site in the tissue to be manipulated. As the steerable instrument22is advanced out of the distal end21of the access cannula18, the steerable instrument22may be simultaneously actuated while the deflectable portion48of the steerable instrument22is disposed within the deformable conduit24to move the distal end23of the steerable instrument22and the distal end25of the deformable conduit24away from the longitudinal axis A of the access cannula18such that the deformable conduit24occupies the deformed position. The step of actuating the steerable instrument22comprises deflecting the deflectable portion48of the steerable instrument22to the curved configuration. As the steerable instrument22is actuated to cause the deflectable portion48to curve, the distal end25of the deformable conduit24moves in the same direction, resulting in the formation of a channel, void, or cavity in the tissue. The clinician can influence the size and shape of the channel based on the degree of actuation of the steerable instrument22and whether the steerable instrument22is rotated during actuation. The deformed position is defined as a position of the deformable conduit24assumed after the steerable instrument22urges the distal end25of the deformable conduit24away from the distal end of the access cannula18. Accordingly, the deformable conduit24can assume a variety of deformed positions, each having a different angle of curvature and radius based on the position of the distal end25of the deformable conduit24relative to the longitudinal axis A of the access cannula18. In this manner, a clinician may determine a desirable curvature to reach the target site and actuate the steerable instrument22to a degree sufficient so that the deflectable portion48assumes the desired angle of curvature and radius, which in turn deforms the deformable conduit24to assume substantially the same angle of curvature. The clinician is able to observe the placement of the various components under intraoperative imaging due to inherent radiopacity of certain elements of the steerable assembly20 The step of actuating the steerable instrument22comprises manually engaging the control surface58. This manual engagement may comprise squeezing, rotating, or sliding the control surface58to actuate the control element54of the steerable instrument22. The clinician may obtain feedback on the degree of actuation from indices previously described (visible, tactile, audible) and by direct visualization steerable assembly20in the tissue with intraoperative imaging. Actuation of the control element54(or control surface58) may be performed at any time during the advancement of steerable assembly20, including before, during, or after the distal end of the steerable assembly20has entered the tissue. There may be certain advantages to actuating before the steerable instrument22begins exiting distal end of the access cannula18. This causes potential energy to be stored within the steerable instrument22, which results in immediate lateral deflection of the deflectable portion48of steerable instrument22as the steerable instrument22is advanced distally from the access cannula18. The clinician may employ feedback from the device (visible, tactile, or audible) to impart a desired amount of energy to the mechanism that will result in a desired amount of curvature upon advancement. If the steerable instrument22includes a locking mechanism as described before, the clinician may stop applying force to the control element54(or control surface58) and allow the locking mechanism to retain and release the stored energy during advancement of the steerable assembly20. This may allow the clinician to focus less attention on actuating the steerable instrument22and more on safely reaching the target location in the tissue. The method may, upon reaching the target tissue, comprise locking the hub28of the deformable conduit assembly26at least axially in place with respect to the access cannula18, which allows passage or withdrawal of instruments within the deformable conduit24without moving the deformable conduit24. The locking mechanism may allow the deformable conduit24to rotate relative to the access cannula18to facilitate rotation of the steering instrument22or other instrument disposed within the deformable conduit24. In one exemplary embodiment, the step of locking the hub28of the deformable conduit assembly26axially in place with respect to the access cannula18comprises rotating the lock ring34to lock the hub28of the deformable conduit assembly26in place. Referring toFIG.25, the method may further comprise retracting and removing the steerable instrument22from the deformable conduit24after actuation of the steerable instrument22. This includes retracting the steerable instrument22from the deformable conduit24when the control element54is operating in the slack tension mode without causing the deformable conduit24to deviate substantially from the deformed position. The steerable instrument22is generally retracted in an axial direction from within the deformable conduit24such that the deformable conduit24is no longer occluded by the steerable instrument22and can allow other components to be disposed within the lumen of the deformable conduit24, such as the expandable structure128or the implant140. In certain embodiments, the method may comprise releasing the tension of the steerable instrument22before retracting the steerable instrument22from the deformable conduit24such that the distal end23of the steerable instrument22is adapted to readily conform to the deformed position of the deformable conduit24without causing the deformable conduit24to be substantially displaced from the deformed position. In one embodiment, the step of releasing may comprise operating in the slack tension mode of the steerable instrument22. By releasing the tension of the steerable instrument22before retracting, the deformable conduit24is less likely to be deformed by the retraction of the steerable instrument22. Reducing the amount of deformation ensures that the distal end25of the deformable conduit24remains adjacent to the target site, which allows precise placement of the implant140and/or the expandable structure128. Referring toFIGS.26-28, in some embodiments the expandable member126is utilized. The method comprises inserting the expandable member126through the deformable conduit24(FIG.26), retracting the deformable conduit24to expose the expandable structure128(FIG.27), and expanding the expandable structure128to form a cavity in the tissue (FIG.28). In such embodiments, the step of placing the implant140is further defined as placing the implant140at least partially within the cavity formed by the expandable structure128. Once the cavity is formed, the expandable structure128may then be returned to its contracted (e.g., deflated) state, and retracted from the deformable conduit24. The clinician identifies the shape of the tissue to be displaced and the local structures that could be damaged if the expandable structure128were expanded in an improper fashion. The clinician is also able to identify the expanded shape of the expandable structure128inside tissue based upon prior analysis of the morphology of the target site using, for example, plain film x-ray, fluoroscopic x-ray, or MRI or CT scanning. When the expandable structure128is used in bone in combination with a hardenable material, the expanded shape inside is selected to optimize the formation of a cavity that, e.g., when filled with the hardenable material, provides support across the region of the bone being treated. The expandable structure128is typically sized such that at least 25, 50, 75, or 90, % of cancellous bone16should be compressed. The step of expanding the expandable member126may result in contacting tissue with the expandable structure128, such as cancellous bone16. In some configurations, the step of expanding the expandable structure128to form a cavity is further defined as expanding the expandable structure128in a position radially offset from the longitudinal axis A of the access cannula18. The method further comprises locking the expandable member126in place such that the expandable member126is restricted from moving in a longitudinal direction with respect to the access cannula18. The expandable member126may be locked in position relative to the hub28of the deformable conduit assembly26, thus statically defining the position of the expandable structure128with respect to the access cannula18. This locking may allow independent motion of the deformable conduit24relative to the expandable structure128. Referring toFIG.27, the method may further comprise retracting the deformable conduit24in a longitudinal direction relative to the access cannula18while the expandable member126remains in a substantially constant position with respect to the access cannula18such that at least a portion of the expandable structure128becomes at least partially uncovered by the deformable conduit24. The expandable structure128may be fully uncovered, or may be uncovered by only 25, 35, 45, 55, 65, 75, or 85 or more, %, based on the longitudinal dimension of the expandable structure128. In embodiments where the expandable structure128is not fully uncovered, the method may comprise expanding the expandable structure128while the expandable structure128remains at least partially disposed and constrained within the deformable conduit24. This may allow the clinician to more directly control the shape of the cavity created by the expandable structure. The clinician may use indicia (visible, tactile, or audible) provided with the deformable conduit24or expandable structure128to set the amount of desired exposure of the expandable member126. Referring again toFIG.24, the method includes placing an implant140into the tissue through the access cannula18or the deformable conduit24. The step of placing the implant140may further comprise injecting the hardenable material into the channel formed by the steerable assembly20. Alternatively, the step of placing the implant140may further comprise placing the hardenable material through the deformable conduit24. In certain embodiments, the method comprises locking the implant delivery system142in place with respect to the access cannula18and the hub28of the deformable conduit24, which allows the deformable conduit24to move axially with respect to the implant delivery system142, without substantially moving the implant delivery system142or the access cannula18. Along these lines, the method may comprise retracting the deformable conduit24in a longitudinal direction relative to the access cannula18while simultaneously urging hardenable material through the deformable conduit24. This allows the hardenable material to occupy the entire channel once occupied by the deformable conduit24in the tissue to be displaced. The retraction may be performed gradually at a variety of speeds. It is to be understood that the appended claims are not limited to express and particular systems or methods described in the detailed description, which may vary between particular embodiments that fall within the scope of the appended claims. It is also to be understood that any ranges and subranges relied upon in describing various embodiments of the present disclosure independently and collectively fall within the scope of the appended claims and are understood to describe and contemplate all ranges, including whole and/or fractional values therein, even if such values are not expressly written herein. One of skill in the art readily recognizes that the enumerated ranges and subranges sufficiently describe and enable various embodiments of the present disclosure and such ranges and subranges may be further delineated into relevant halves, thirds, quarters, fifths, and so on. As just one example, a range “of from 0.1 to 0.9” may be further delineated into a lower third, i.e., from 0.1 to 0.3, a middle third, i.e., from 0.4 to 0.6, and an upper third, i.e., from 0.7 to 0.9, which individually and collectively are within the scope of the appended claims and may be relied upon individually and/or collectively and provide adequate support for specific embodiments within the scope of the appended claims. In addition, with respect to the language which defines or modifies a range, such as “at least,” “greater than,” “less than,” “no more than,” and the like, it is to be understood that such language includes subranges and/or an upper or lower limit. As another example, a range of “at least 10” inherently includes a subrange of from at least 10 to 35, a subrange of from at least 10 to 25, a subrange from 25 to 35, and so on, and each subrange may be relied upon individually and/or collectively and provides adequate support for specific embodiments within the scope of the appended claims. Finally, an individual number within a disclosed range may be relied upon and provides adequate support for specific embodiments within the scope of the appended claims. For example, a range “of from 1 to 9” includes various individual integers, such as 3, as well as individual numbers including a decimal point (or fraction), such as 4.1, which may be relied upon and provide adequate support for specific embodiments within the scope of the appended claims. The disclosure has been described in an illustrative manner and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the present disclosure are possible in light of the above teachings and the disclosure may be practiced otherwise than as specifically described.

11857220

DESCRIPTION FIG.1, a protective device for use during surgery according to an embodiment is illustrated. Protective device100comprises an expandable body10and an inner member12located at least partially within expandable body10. Expandable body10comprises a layer14of silicone over-molded onto inner member12in the form of PVA or EVA open or closed cell foam. In use, it is envisaged that silicone layer14may provide resistance to energy and/or contact burns from a surgical tool and the inner member12may thermally insulate the tissue to be protected. Inner member12comprises at least one stand-off16which assists in maintaining inner member12in a centralized and substantially planar orientation during over-molding. Inner member12comprises a plurality of cavities17oriented about the fold lines (not shown) which may assist in compressing or folding the protective device into an insertion condition. It is envisaged that in an embodiment comprising a closed cell foam inner member, such as a memory foam, the expandable body10expands as the inner member12self-inflates. It is envisaged that, in an embodiment comprising an open cell foam inner member, inner member12may be expanded by contacting at least one stand-off16with an expansion fluid or by injecting an expansion fluid directly into the inner member12. Protective device100further comprises a retention member20associated with expandable body10. In use, retention member20may be used to by a user to withdraw protective device100from a patient's body. InFIG.2, a protective device for use during surgery according to an embodiment is illustrated. Protective device200comprises an expandable body30and an inner member22located at least partially within expandable body30. Expandable body30comprises a layer24of silicone over-molded onto inner member22in the form of PVA or EVA open cell foam. In use, it is envisaged that the silicone layer may provide resistance to energy and/or contact burns from a surgical tool and the open cell foam layer may thermally insulate the tissue to be protected. Inner member22comprises at least one stand-off26which assists in maintaining inner member22in a centralized and substantially planar orientation during over-molding. Inner member22comprises one or more portions oriented about the fold lines (not shown) of protective device200. In this way, the amount of material in the region of the fold lines is reduced which assists in folding the protective device into an insertion condition. In use, it is envisaged that inner member22may need to be compressed under vacuum to assist in folding the protective device into an insertion condition or to deflate the inner member such that the protective device may be removed from the patient's body. In use, it is envisaged that in an embodiment comprising an open cell inner member, that inner member22may be expanded by contacting at least one stand-off26with an expansion fluid or by injecting an expansion fluid directly into the inner member22. It is envisaged that in an embodiment comprising a closed cell foam inner member, such as a memory foam, the expandable body30expands as the inner member22self-inflates. Protective device200further comprises a retention member40associated with expandable body30. In use, retention member40may be used to by a user to withdraw protective device200from a patient's body. InFIG.3, a protective device for use during surgery according to an embodiment of the invention is illustrated. Protective device300comprises an expandable body50, an inner member32located at least partially within expandable body50, and an expansion portion38associated with expandable body50and configured to facilitate expansion thereof. Expandable body50comprises a layer34of silicone over-molded onto inner member32in the form of an elongate material such as pneumatic tubing. In use, it is envisaged that silicone layer34may provide resistance to energy and/or contact burns from a surgical tool and the air pockets37between the elongate material32may thermally insulate the tissue to be protected. Inner member32comprises at least one stand-off36which assists in maintaining inner member32in a centralized and substantially planar orientation during over-molding. Inner member32comprises a plurality of elongate material oriented along the fold lines (not shown) which when deflated may assist in compressing or folding the protective device into an insertion condition. In use, it is envisaged that a user may inject an expansion fluid into expansion portion38, expanding the pneumatic tubing32and subsequently, expandable body50. Alternatively, a user may expand the expandable body50by contacting at least one stand-off36with an expansion fluid or by injecting an expansion fluid directly into the at least one stand-off36. Protective device300further comprises a retention member60associated with expandable body50. In use, retention member60may be used to by a user to withdraw protective device300from a patient's body. InFIG.4, an expansion portion of a protective device is illustrated. A syringe42is used to inject an expansion fluid into expansion portion38of protective device300. InFIG.5A to5C, a protective device400comprising an expandable body44is illustrated. In use, expandable body44in a fully expanded condition (FIG.5A) is deflated and then folded along fold lines46to form a partly folded protective device in a substantially square configuration (FIG.5B) and rolled into an insertion condition (FIG.5C). InFIGS.6and7, a surgical apparatus comprising a surgical instrument and a protective device for insertion into a patient's body is illustrated. Surgical instrument600comprises an end effector54configured to receive at least a portion of protective device500therein. End effector54is actuated by an actuating portion56in the form of a trigger device attached to handle52of the surgical instrument to move end effector54between a closed configuration and an open configuration. It is envisaged that in use, moving end effector54to an open configuration may allow protective device500to be inserted into or removed from end effector54. End effector54comprises anchoring portion65configured to retain at least a portion of retention member64of protective device500in connection with surgical instrument600. InFIG.8, a surgical apparatus comprising a surgical instrument and a protective device for insertion into a patient's body is illustrated. Surgical instrument800comprises a housing portion90configured to receive a protective device therein (not shown) and a plunger102configured to release the protective device into a patient's body (not shown). Housing portion90comprises a bore (not shown) extending from a first end92to an opposed second end94and a flange98located at a first end92of the housing portion90. Bore opening96of housing portion90is configured to receive plunger102therein. Plunger102comprises a first end104and an opposed second end106, a flange110located at a first end104of plunger102and a recessed portion108extending longitudinally along the length of plunger102. It is envisaged that in use, a retention member (not shown) of a protective device may be passed through the bore (not shown) of housing portion90and out bore opening96, the retention member (not shown) may be positioned in recessed portion108of plunger102and removably secured to anchoring portion112via slot114and plug portion86. InFIGS.9A to9G, a side perspective of a surgical apparatus comprising a surgical instrument for insertion of a protective device into a patient's body is illustrated. For clarity, a patient's body is not shown, however it will be understood that a canula122of a trocar may be inserted into a patient's body through an incision whilst the upper portion123of the trocar will remain outside the patient's body. Surgical instrument800comprising a housing portion90and plunger102and a protective device located within the bore of the housing portion90may be inserted into access port118of trocar116until flange98located at a first end of housing portion90abuts an upper surface of trocar116. Plunger102is depressed until flange110located at a first end of plunger102abuts an upper surface of flange98of housing portion90. As a result of the linear movement of plunger102in the bore (not shown) of housing portion90, protective device80is released through second end94of housing portion90into a patient's body. As expandable body82of protective device80expands from an insertion condition, retention member84unspools into the patient's body. In use, plug portion86of retention member84and anchoring portion112retain the retention portion84in connection with surgical instrument800. After protective device80is released into a patient's body cavity, plunger102may be removed from the bore of housing portion90. In use, it is envisaged that retention member84and anchoring portion112are removed from recessed portion108and flange110of plunger102respectively. Housing portion90may then be removed from access port118of trocar116. In use, it is envisaged that retention member84is removed from slot114of anchoring portion112allowing retention member84to pass through the bore of housing portion90. Retention member84is placed to the side so as to retain connection with protective device80during surgery. It is envisaged, that in use, protective device80may be removed from a patient's body by deflating expandable body82and withdrawing expandable body82through trocar116. Alternatively, trocar116may be removed, allowing the deflated expandable body82to be withdrawn through the incision in the patient's body. Referring toFIGS.10to17, another preferred embodiment of a protective assembly1000has been illustrated. The protective assembly1000includes a protection member comprising a thin membrane1100formed from non-toxic medical grade material such as but not limited to medical grade silicone or any other type of resilient and flexible polymeric material. The protection membrane1100comprises an overall triangular or wing shaped configuration with rounded corners or vertices. The importance of the shape of the membrane1100will be described in greater detail in the foregoing sections. The thickness of the membrane1100is sufficiently small relative to its overall dimensions. As a result, the membrane1100is sufficiently thin and maneuverable to enable the membrane1100to be rolled into a hollow cannula of a laparoscopic trocar1200. The membrane1100is configured to be unfurled or expanded and spread into a protective configuration after being passed through the cannula of the trocar1200once introduced within the patient's body through the trocar1200. In such a protective configuration, the membrane1100may be spread over the patient's internal organs to shield the patient's organs whilst laparoscopic surgery is being carried out. At least a peripheral portion of the membrane1100includes a flexible connector1150(of indefinite length) that connects the membrane1100to a distal end portion1310(shown inFIGS.14and15) of a plunger1300. The plunger1300is provided to push the membrane1100(in a rolled configuration) into the cannula of the trocar1200. Specifically, one end of the flexible connector1150is anchored to a distal tip1310of the plunger and the other end of the flexible connector1150is fused with the matrix of the membrane1100. The point1152(shown inFIG.16) at which the flexible connector1150connects with the membrane1100is preferably reinforced or strengthened to further reduce the likelihood of the flexible connector1150becoming accidently uncoupled from the membrane1100. FIGS.10A to10DandFIG.12show the plunger1300in a fully inserted configuration whereby a shaft1320portion of the plunger1300has been fully inserted into the cannula of a laparoscopic trocar1200.FIGS.14A to14Dshow the plunger1300in a withdrawn position (withdrawn out of the cannula of the trocar1200). Referring toFIG.12in particular, the plunger1300includes an enlarged head1330that is sized to be received and seated on an entrance portion1220of the trocar1200. The entrance portion of the trocar1200comprises a flattened flanged seat1205with wings or tabs1207extending radially from the seat1205so that the surgeon can place their fingers under the tabs1207to hold the trocar1200. The plunger head1330is structured to be larger than the diameter of the cannula of the trocar1200to stop the plunger1300from falling through the cannula inside the patient's body. The membrane1100comprises two major surfaces separated by a thickness of the membrane1100. The major surfaces of the membrane1100comprise a substantially identical configuration with a plurality of fold regions to enable the membrane1100to be folded or bent (to enable rolling). Each of the major surfaces of the membrane1100(detailed sectional views shown inFIGS.16and17). Each surface of the membrane1100comprises alternating rows of projections1120and recesses1140such that any two adjacently located projections1120are separated by a recess1140resulting in the said alternating configuration. Each recess1140on one of the major membrane surfaces of the membrane1100is shaped to form a trough and aligned with a projection1140on the other of the major membrane surfaces of the membrane1100. It is also important to note that each of the projections1120or recesses1140on the major membrane surfaces extend in a transverse (preferably orthogonal direction) relative to a direction of the rows of the projections1120and recesses1140. It is also apparent that heights for each of the projections1120(and depths of the recesses1140) are substantially equal. In the preferred embodiment, the height for each projection1120and recesses1140lies in the range of 0.5 mm to 1 mm and more preferably between 0.25 mm and 0.75 mm. In at least some embodiments, the height may be 0.5 mm. Regions of the membrane1100form a matrix within which the projections1120and recesses1140and these membrane regions1130have a relatively lower thickness compared to the other regions where the projections1120and recesses1140are provided. The thickness of these regions preferably lies between 0.5 mm and 1 mm. The membrane regions with relatively lower thickness provide a plurality of fold regions along which the membrane1100can be easily bent (for rolling) or folded. The overall thickness of the membrane1100is the sum of the thickness of the these membrane regions1130, height of the projections1120and depth of the recesses1140. Therefore, if the membrane region1130is 0.5 mm and each of the projections have an average height of 0.5 mm and each of the recesses have an average depth of 0.5 mm, then overall thickness of the membrane1100would 1.5 mm. The membrane1100in the preferred embodiment comprises a unique shape and provides several important advantages. Specifically, the membrane1100, when positioned on a flat surface, comprises two linear peripheral portions1101and1103that are substantially perpendicular to each other. These two perpendicular linear portions1101and1103are bridged by a first arcuate bridging portion1102(with a relatively shorter arc length) and a second bridging portion1104(with a relatively longer arc length) which results in the membrane1100, particularly the membrane surfaces having a wing shaped configuration. The flexible connector1150may be formed from the same material as the membrane and may also be fused with the membrane1100as previously explained. The instantaneous width (ie. width across the connector1150along any section) of the flexible connector1150is substantially less than the overall diameter of the cannula of the trocar1200. Such a configuration allows surgeons to use the plunger1300to insert the membrane1100(in a rolled configuration) through the cannula into the patient's body and then spreading the membrane1100to shield internal organs of the patient before commencing laparoscopic surgery. Whilst the surgery is being conducted, the plunger1300might be pulled out leaving behind a sufficient length of the flexible connector1150passing through the cannula of the trocar1200. The plunger1300may be pulled out and placed aside whilst still being connected to the membrane1100by the long flexible connector1150. Preferably, the length of the flexible connector1150should be much greater than the length of the cannula of the trocar to allow the membrane1150to be placed within the patient's body whilst the flexible connector passes through the cannula whilst still being coupled with the distal portion of the plunger1300. Since the flexible connector1150is dimensioned to be substantially small, there is enough vacant volume within the cannula of the trocar1200to allow insertion of other laparoscopic effectors to carry out laparoscopic surgery while the membrane1100. Once the laparoscopic surgery has concluded, the surgeon may withdraw the membrane1100by pulling out the membrane through the cannula. The flexible connector1150is attached to a convergent peripheral portion of the membrane such that the convergent peripheral portion converges generally in a direction towards the connector to facilitate rolling or folding of the membrane1100when pulled into the cannula of the trocar1200during use. The membrane1100gradually broadens from a location of attachment of the connector1150on the membrane1100which results in the membrane1100being rolled easily into the cannula of the trocar1200thereby facilitating the withdrawal of the membrane1100. The membrane1100comprises40durometer medical grade silicone material, which is formulated for use in health care applications. The silicone base polymer used on the medical grade silicone material in the preferred embodiment of the membrane1100is a low volatile, peroxide free, platinum cured material that will not discolor over time.40durometer medical grade silicone is likely to perform well under extreme high temperatures, with capability to operate in a range of −65° C. to +232° C. The silicone material of the membrane1100assists with providing heat resistance to the membrane1100. The configuration of the membrane1100with alternating rows of projections1120and recesses1140further improves heat insulation and allows bending and stretching of the membrane1100and prevents tears across the membrane1100. In the present specification and claims (if any), the word ‘comprising’ and its derivatives including ‘comprises’ and ‘comprise’ include each of the stated integers but does not exclude the inclusion of one or more further integers. Reference throughout this specification to ‘one embodiment’ or ‘an embodiment’ means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases ‘in one embodiment’ or ‘in an embodiment’ in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations. In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art.

11857221

DETAILED DESCRIPTION A detailed description of apparatus, systems, and methods consistent with various embodiments of the present disclosure is provided below. While several embodiments are described, it should be understood that the disclosure is not limited to any of the specific embodiments disclosed, but instead encompasses numerous alternatives, modifications, and equivalents. In addition, while numerous specific details are set forth in the following description in order to provide a thorough understanding of the embodiments disclosed herein, some embodiments can be practiced without some or all of these details. Moreover, for the purpose of clarity, certain technical material that is known in the related art has not been described in detail in order to avoid unnecessarily obscuring the disclosure. Apparatus, methods, and systems are disclosed herein relating to spinal fixation or other bone fixation. In some embodiments, tether clamping assemblies may be provided, such as clamping assemblies used to clamp a tether about a spinal feature to assist in spinal fixation. More particularly, in some embodiments, a tether clamping assembly may also be configured to engage a spinal fixation rod. In preferred embodiments, the clamping assembly may be configured such that one or more portions of a tether may be self-locked therein without requiring any additional locking elements, features, or steps. In this manner, for example, a tether may be looped around a spinal feature or other anatomical feature, coupled with a fixation element, such as a rod, and then locked in place to stabilize the anatomical feature. The embodiments of the disclosure may be best understood by reference to the drawings, wherein like parts may be designated by like numerals. It will be readily understood that the components of the disclosed embodiments, as generally described and illustrated in the figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the apparatus and methods of the disclosure is not intended to limit the scope of the disclosure, as claimed, but is merely representative of possible embodiments of the disclosure. In addition, the steps of a method do not necessarily need to be executed in any specific order, or even sequentially, nor need the steps be executed only once, unless otherwise specified. Additional details regarding certain preferred embodiments and implementations will now be described in greater detail with reference to the accompanying drawings. FIG.1is an exploded view of a spinal fixation assembly100according to some embodiments. Assembly100comprises a tether110that is configured to engage a spinal feature of a patient's spine, such as, in preferred embodiments, looped around the spinal lamina and/or other spinal features, such as the transverse processes of the patient's spine. Tether110in some embodiments, may comprise a flat, flexible band resembling, for example, a piece of tape. In preferred embodiments, tether110may be flat and/or smooth on both opposing sides. For example, in preferred embodiments tether110may be devoid of locking teeth and/or other projections. Assembly100further comprises a tether clamping assembly130configured to engage and couple a coupling member, such as a rod120or other elongate member, with the tether110so as to facilitate coupling of a patient's spine in a desired position without use of pedicle screws or other similar bone-invasive components. Assembly100further comprises a cap160configured to engage tether clamping assembly130, as described in greater detail below. Although preferred embodiments disclosed herein, including assembly100, may be configured to allow for coupling of a tether with spinal features, it is contemplated that the inventive principles disclosed herein may be applied to provide for clamping/securing of a tether to other anatomical features, such as securing two portions of a broken or cracked bone, such as a femur, for example. In some such embodiments not involving spinal anatomy, the spinal rod or other fixation member discussed below may be omitted. In some such embodiments, the bone itself may be clamped by the clamping assembly130instead of clamping both the tether and the rod/fixation member. FIG.2Ais a side elevation view of spinal fixation assembly100. As shown in this figure, tether clamping assembly130comprises two separate pieces, namely, a first or inner coupling piece140and a second or outer coupling piece150configured to be coupled with the first coupling piece140. First/inner coupling piece140defines a slot145for receipt of a rod120or other elongate and/or rigid coupling member therethrough. Preferably, slot145is shaped to match, or at least substantially match, the shape of the outer surface of rod120such that rod120may be firmed engaged/gripped by slot145. In some embodiments, slot145may comprise a plurality of engagement features141, such as teeth, grooves, spikes, or a contoured and/or roughened surface to further facilitate a firm engagement between rod120and inner coupling piece140. This roughening may be applied, in some embodiments, by way of diamond plating, blasting, etc. In some embodiments, one or both of the coupling pieces may comprise features that allow for slot145to resiliently flex to receive rod120therein and then snap back in place to fixedly engage rod120, as discussed in greater detail below. In embodiments providing a snap-on feature, slot145may also be roughened, textured, and or provided with teeth or other engagement features141, as mentioned above. In this manner, the inner coupling piece140may be snapped onto the rod120and the inner coupling piece140may be held in place on the rod without requiring a practitioner to hold it in place by virtue of the engagement features141and/or a textured or roughened surface. However, in order to allow the inner coupling piece140to be slid to its desired location on the rod120, it may be preferred that the frictional engagement be configured so as to allow a practitioner to manually overcome the friction to move the inner coupling piece140and/or assembly100as needed during surgery. FIG.2Bis a cross-sectional view of spinal fixation assembly100. As depicted in this figure, first/inner coupling piece140is configured to be received within second/outer coupling piece150in a nesting fashion. In some embodiments, including the depicted embodiment, first/inner coupling piece140is configured to be wholly received within second/outer coupling piece150. However, it is contemplated that, in other embodiments, a portion of the outer coupling piece may protrude from the inner coupling piece or, as discussed in connection with another embodiment below, tether clamping assembly130may instead comprise a single element. Second/outer coupling piece150may similarly comprise a slot155that may be configured to be aligned with slot145upon coupling inner coupling piece140with outer coupling piece150. By coupling inner coupling piece140with outer coupling piece150, a pair of opposing passages are defined for receipt of separate portions of tether110therethrough. Thus, first and second passages may be defined, respectively, by an inner surface152of outer coupling piece150and an outer surface142of inner coupling piece140, both of which may be configured to receive separate portions of tether110therethrough. In preferred embodiments, clamping assembly130is self-locking. In other words, by advancing tether110through one or both passages, the tension on tether110alone results in a tightening, and preferably a locking, of tether110in clamping assembly130. Preferably, clamping assembly130is configured such that tether110can be clamped and/or locked in clamping assembly130so as to allow tether110to move through one or both passages in a first direction to lock the tether in place but so as to prevent, or at least substantially prevent, tether110from moving through one or both passages in a second direction opposite from the first direction. Thus, with respect to the view ofFIGS.2A and2B, tether110may be advanced in an upward direction along both opposing passages, thereby resulting in a tether loop (seeFIG.1) that gets smaller, but may be prevented, or at least substantially prevented, from being advanced in a downward direction. Thus, upon applying a force to tether110in the upward direction, the loop locks in place, preferably about a spinal feature. In some embodiments, the greater the force applied in a locking direction, the tighter the lock, and therefore the more difficult it is to move the tether in an opposite direction from the locking direction. In the depicted embodiment, this self-locking feature may be enhanced by providing a friction differential between the two opposing surfaces through which one or more portions of tether110are received. Preferably, this friction differential is applied such that a movable surface has a greater surface roughness than an opposing non-movable surface. Because, as discussed in greater detail below, in some implementations of inventive methods disclosed herein, the inner coupling piece140may be coupled with a rod120or other elongate member prior to coupling outer coupling piece150with inner coupling piece140, outer coupling piece150may be considered the “moveable” element of clamping assembly130. Thus, for example, as depicted inFIG.2B, inner surface(s)152of outer coupling piece150comprises a plurality of projections153. In some embodiments, projections153may be defined by a plurality of elongated grooves formed on the inner surface152of outer coupling piece150. However, alternative embodiments are contemplated in which projections153may comprise, for example, teeth. As still another alternative, inner surface152of outer coupling piece150may, in some embodiments, lack deliberately formed projections and may instead simply comprise a roughened surface. Outer surface(s)142of inner coupling piece140may, in some embodiments, comprise a smooth surface. However, so long as a friction differential is provided, whether by providing projections153or otherwise, outer surface(s)142need not be smooth in some embodiments. Surfaces142and152, along with their respective surface features, are therefore an example of means for self-locking a tether within a rod-coupling assembly. It is also contemplated, however, that, in some embodiments, suitable locking may be provided without providing the friction differential described above. For example, the embodiment depicted inFIG.2Balso provides for self-locking of tether110by virtue of a wedge-locking feature. Thus, although it may be preferred to have the two opposing surfaces142/152have a friction differential, this may be omitted in certain contemplated embodiments. In embodiments in which these two surfaces are identical, or at least substantially identical, it is also preferred that both surfaces be roughened, contoured, and/or formed with frictional features, such as teeth or protrusions, for example. However, it is also contemplated that for certain applications opposing surfaces142/152may instead both be smooth. Because of the unique design of assembly100, locking of tether110may also result in further locking/tightening of the grip on rod120. For example, due to the wedging of outer coupling piece150onto inner coupling piece140, as the tension on tether110is increased in the tightening direction by pulling one or both ends of tether110through the two opposing passages defined by outer coupling piece150and inner coupling piece140, not only is tether110pinched more tightly therebetween to prevent it from being loosened, but, at the same time, the slot145created by the inner surface of inner coupling piece140is squeezed against the rod120more tightly to further lock the tether clamping assembly130in place with respect to the rod120. This feature is provided for by virtue of the wedge lock previously described, in which two tapering surfaces are wedged against each other (with the tether110therebetween) in combination with making the inner coupling piece140flexible so that the size of slot145can vary to facilitate this compression. Preferably, as shown in the depicted embodiment, these tapering surfaces are frusto-conical surfaces. Other aspects/features of spinal fixation assembly100can be seen inFIGS.3-8. For example, as shown inFIG.3, inner coupling piece140may comprise a central opening147, which may be threaded to receive cap160. Opening147may be configured to be aligned with opening157of outer coupling piece150, as shown inFIG.5, upon coupling of outer coupling piece150with inner coupling piece140. Although preferably openings147and157are configured to be aligned when outer coupling piece150is coupled with inner coupling piece140, opening157need not be threaded since threaded opening147may engage cap160and thereby engage outer coupling piece150without itself requiring a direct threaded connection with cap160. In some embodiments, cap160may be configured to contact, either directly or indirectly, rod120, so as to increase the locking force that may be desired thereon. In some such embodiments, the end of the threaded shaft of cap160may therefore comprise a spiked tip, one or more grooves, protrusions, or surface roughened features to enhance the grip between cap160and rod120. Inner coupling piece140may further comprise opposing grooves144. Grooves144may be provided in order to increase the flexibility of slot145. For example, as previously mentioned, slot145may be configured to expand to receive rod120and then resiliently snap back in place to at least partially envelop rod120, which functionality may be provided by grooves144. In some embodiments, grooves144may also, or alternatively, be used to provide locations to facilitate gripping/engagement by an instrument that may be used to install coupling piece140and/or hold coupling piece140in place during one or more stages of a surgical procedure. As also better seen inFIG.4, inner coupling piece140may comprise opposing outer surfaces142A and142B, each of which may partially define a separate tether passage. As previously mentioned, preferably, outer surfaces142A and142B are smooth or at least have surface roughnesses that are less than that of respective opposing surfaces, which may be defined by outer coupling piece150, that, together with outer surfaces142A and142B, define opposing tether passages. Similarly,FIG.4better depicts opposing grooves144A and144B, which directly extend from opposing outer surfaces142A and142B, respectively. As best shown in this figure, grooves144A and1446, together with slot145, form opposing narrowed portions that provide the aforementioned flexibility and/or provide engagement locations for a suitable instrument. FIG.5is a perspective view of outer coupling piece150. As best seen in this figure, the upper portion of outer coupling piece150may comprise one or more features to facilitate desired functionality. For example, as previously mentioned an opening157may be provided to receive a threaded projection or another projection from a cap and/or set screw. In addition, opening157need not be threaded, but may be defined by a plate151configured to engage a portion of inner coupling piece140that defines a threaded opening147configured to be aligned with opening157such that inner coupling piece140can extend into but cannot extend out of the opposite end of outer coupling piece150. Plate151may also be configured to provide a surface upon which a flanged portion164of cap160may rest and/or pinch a portion of tether110, as discussed in greater detail below. Plate151may further define opposing tether openings156A and156B. In embodiments using a tether having an elongated, rectangular cross-section, such as tether110, tether openings156A and156B may have a similar matching shape such that the tether may snap into place when properly oriented within the opposing passages, the openings at one end of which are defined by tether openings156A and156B. Tether openings156A and156B may be partially defined by four corners158that are positioned along the portion of outer coupling piece150defining opening157. Corners158are defined by opening157along with respective walls that extend parallel to slit155(and therefore extend parallel to an axis defined by a rod positioned therein). These tether openings156A/156B may be useful in allowing the tether to be held in place temporarily (before locking/clamping) to allow a practitioner to perform other tasks while awaiting finalization of the installation/surgery. As also shown inFIG.5, opposing slits159A and159B may be formed adjacent to plate151. As best seen inFIG.8, which depicts assembly130with cap160in place, slits159A and159B may, together with flanged portion164of cap160, define opposing apertures through which opposing portions of tether110may exit from opposing sides of assembly130. Some embodiments may further comprise one or more features to facilitate engagement with a suitable instrument. Thus, for example, outer coupling piece150comprises a notch154, which may engage a corresponding protruding element of a suitable surgical instrument. Although not visible inFIG.5, in some embodiments, a similar notch may be formed on the opposite side of outer coupling piece150. FIG.6more clearly depicts projections153formed within curved inner surface152A of outer coupling piece150. As shown in this figure, projections153may be formed by cutting elongated, parallel grooves within inner surface152A. Although not visible inFIG.6, as previously mentioned, in preferred embodiments, the opposing inner surface similarly comprises a plurality of projections153to facilitate the self-locking feature of assembly130. FIG.7is a perspective view of a cap160of spinal fixation assembly100according to some embodiments. Cap160comprises a flanged portion164, which may be configured to engage an upper surface of outer coupling piece150, such as plate151. Cap160further comprises a male threaded portion162and a keyed slot161. As previously mentioned, male threaded portion162may be configured to engage female threads of inner coupling piece140and outer coupling piece150may be clamped therebetween. Keyed slot161may be configured to engage an instrument, such as a driver, used to couple cap160to assembly130. In some embodiments, a portion or, in some such embodiments, two opposing portions, of the tether110may be clamped in between flanged portion164of cap160and another portion of assembly130, such as the ledges formed by opposing slits159A and159B or plate151of outer coupling piece150. Thus, cap160is an example of secondary means for locking a tether within a rod-coupling assembly. Cap160may also serve the function of increasing the lock on the rod and/or tether and/or decreasing the possibility of unwanted loosening/disassembly. In addition, providing cap160may decrease the possibility of frayed portions of tether110from extending down into assembly130following cutting of tether110. This may allow for cutting of tether110closer to assembly130than may otherwise be possible or desirable. However, as previously explained, self-locking may be provided by the differential friction of the opposing surfaces of one or both tether passages of tether clamping assembly130. Thus, it is contemplated that cap160may be omitted in some embodiments. It is also contemplated that cap160may comprise a set screw lacking a flanged portion in some embodiments. FIG.8is a perspective view of tether clamping assembly130showing inner coupling piece140fully inserted within outer coupling piece150and with cap160fully engaged with inner coupling piece140. Although normally a tether would be engaged between opposing surfaces of inner coupling piece140and outer coupling piece150, respectively, in this configuration, tether110is omitted fromFIG.8to allow for better viewing of certain aspects of assembly130. Most notably, opposing apertures are depicted that may allow for a tether to exit from opposite sides of assembly130. These apertures are defined by opposing slits159(only one of which is visible inFIG.8), respectively, along with a lower surface of flanged portion164of cap160. Another unique aspect of assemblies100and/or130is the ability to loosen the grip/lock/clamp on the tether110for readjustment. As previously mentioned, locking of the tether may be accomplished automatically by engaging the tether110between the opposing surfaces of the inner and outer coupling pieces and pulling the tether through one or both of the openings in the locking direction, with the optional cap160to further enhance this locking of the tether110and/or the rod120. This may allow for sequential tightening of various elements of a spinal fixation system without leaving instrumentation in place while moving to a new location within the system, which may also reduce the instrument tray and decrease surgery time. If loosening is needed, in preferred embodiments, due to the unique features described herein, the tether may be loosened by simply pulling or otherwise tensioning one or both of the free ends of the tether. In the event that the clamp provided by the inner and outer coupling pieces is too tight, such as when a locking cap/nut has been applied, in some embodiments and implementations the outer coupling piece150may be engaged, likely with a suitable instrument, in order to lift the outer coupling piece150away from the inner coupling piece140slightly, which will release the lock on tether110and allow the tether110to be loosened. In some embodiments, notch154may be configured to engage a corresponding element of a suitable surgical instrument in order to facilitate this loosening. FIG.9is a perspective view of an alternative embodiment of a spinal fixation assembly900. Although not depicted inFIG.9, assembly900would typically comprise a tether, which may be similar to tether110, that is configured to engage a spinal feature of a patient's spine, such as, in preferred embodiments, looped around the spinal lamina and/or other spinal features, such as the transverse processes of the patient's spine. Like assembly100, assembly900further comprises a tether clamping assembly930configured to engage and couple a coupling member, such as a rod920or other elongate member, with a tether so as to facilitate coupling of a patient's spine in a desired position without use of pedicle screws or other similar bone-invasive components. Tether clamping assembly930again comprises two separate elements configured to be coupled with one another so as to clamp one or more (preferably two) portions of a tether therein. More particularly, tether clamping assembly930comprises an inner coupling piece940configured to be received within an outer coupling piece950. However, tether clamping assembly930differs from tether clamping assembly130in several ways. For example, as shown inFIGS.9and10, inner coupling piece940comprises a pair of removable tabs, namely, tabs970A and970B. Tabs970A and970B may be configured to facilitate coupling of outer coupling piece950with inner coupling piece940. Tabs970A and970B may comprise a plurality of ridges972. Each ridge972, or each pair of adjacent ridges972, may serve a distinct purpose during the installation process. For example, the top pair of ridges972may be used to prevent the outer coupling piece950from being removed from assembly930during, for example, snapping of the rod920into slot945. The middle pair of ridges972may prevent the outer coupling piece950from dropping all of the way down adjacent to the threaded opening947of inner coupling piece940to provide spacing for an instrument or a surgeon's hand during this stage. Following this stage, the outer coupling piece950may be dropped down below the lowest pair of ridges to allow for threading of the tether through opposing passages defined by respective inner surfaces of the outer coupling piece950and respective, opposing outer surfaces of the inner coupling piece940, as previously described. After threading the tether through these passages, the tether may be tensioned about a spinal feature and/or bone. As previously mentioned, preferably tether clamping assembly930is configured to provide for self-locking of the tether. In other words, in some embodiments, the tether clamping assembly930may be configured such that the tether can be clamped in between opposing surfaces so as to allow the tether to move through the passage(s) in a first direction and lock the tether in place so as to, without any further steps or locking elements/features, at least substantially prevent the tether from moving through the passage(s) in a second direction opposite from the first direction. As also previously mentioned, this self-locking feature may be provided by providing a friction differential between the two opposing surfaces through which one or more portions of the tether are received. Preferably, this friction differential is applied such that a movable surface has a greater surface roughness than an opposing non-movable surface. Thus, for example, as depicted inFIGS.10and11, opposing inner surface(s)952of outer coupling piece950comprises a plurality of projections953, which may be formed by elongated grooves. Outer surface(s)942of inner coupling piece940may, in some embodiments, comprise a smooth surface, or at least a surface lacking projections/grooves. However, again, so long as a friction differential is provided, whether by providing projections953or otherwise, outer surface(s)942need not necessarily be smooth. Surfaces942and952, along with their respective surface features, are therefore another example of means for self-locking a tether within a rod-coupling assembly. Once the tether has been suitably tensioned and locked in place, tabs970A and970B may be removed. In order to facilitate such removal, weakened portions975, such as frangible weakening lines, may be formed in one or both of tabs970A and970B. Inner coupling piece940may also comprise opposing grooves944for increasing the flexibility of slot945and/or facilitate gripping/engagement by a surgical instrument. Like outer coupling piece150, outer coupling piece950comprises an opening957, which may be configured to receive a threaded projection or another projection from a cap and/or set screw. Opening957need not be threaded but may be configured to be aligned with a threaded opening947of inner coupling piece940, as previously described. Outer coupling piece950may further comprise one or more notches954, which may engage a corresponding protruding element of a suitable surgical instrument. However, outer coupling piece950differs from outer coupling piece150in several respects. For example, opposing apertures956are formed in outer coupling piece (only one of which is visible inFIG.11) such that a tether (not shown) may extend through the opposing passages previously mentioned and, instead of exiting from an upper surface, may extend through opposing apertures956formed in side walls of outer coupling piece950. In addition, instead of comprising opposing slits159A and159B in a top surface of the outer coupling piece, as is the case in outer coupling piece150, outer coupling piece950comprises opposing slits959A and959B formed in an inner surface of outer coupling piece950. Opposing slits959A and959B may be configured to partially accommodate ridges972. However, in order to secure outer coupling piece950in a desired position on tabs970A/970B, preferably slits959A/959B are slightly smaller than ridges972such that ridges972prevent passage of outer coupling piece950. Passage of outer coupling piece950beyond a given set of ridges972may be accomplished by, for example, flexing tabs970A/970B. FIG.12depicts yet another alternative embodiment of a spinal fixation assembly1200. Although not depicted inFIG.12, assembly1200would typically comprise a tether, which may be similar to tether110, that is configured to engage a spinal feature of a patient's spine, and an elongated fixation member or other coupling member, such as a rod. Like assemblies100and900, assembly1200comprises a tether clamping assembly1230comprising two separate elements configured to be coupled with one another so as to clamp one or more (preferably two) portions of a tether and rod or another coupling member therein. More particularly, tether clamping assembly1230comprises an inner coupling piece1240configured to be received within an outer coupling piece1250, as previously described. However, tether clamping assembly1230differs from the tether clamping assemblies previously described in several ways. For example, as shown inFIGS.12and15, tether clamping assembly1230comprises an alignment insert1280that is configured to be received within an opening formed within outer coupling piece1250and/or inner coupling piece1240. Alignment insert1280may be used to facilitate coupling of outer coupling piece1250with inner coupling piece1240and/or may be used to facilitate introduction of a set screw (not shown) into inner coupling piece1240. Thus, alignment insert1280may comprise a tip1282, which may be configured with a smaller diameter relative to an adjacent body portion1284so as to allow for receipt of tip1282within one or both of threaded opening1247of inner coupling piece1240(seeFIG.13) and opening1257of outer coupling piece1250(seeFIG.14). Opposite from tip1282is a handle1286, which may be configured to allow a surgeon or practitioner to push alignment insert1280into one or more receiving openings to facilitate introduction and coupling of a set screw into threaded opening1247. A central bore1285may be formed in alignment insert1280and may extend from handle1286to tip1282to allow for a set screw to travel therethrough. A suitable instrument may also be received within bore1285to further facilitate such coupling. A perspective view of the inner coupling piece1240is shown inFIG.13. As shown in this figure, inner coupling piece1240comprises a pair of opposing outer surfaces, namely surfaces1242A and1242B. As previously discussed, surfaces1242A and1242B, respectively, may be configured to define one side of a passage for receipt of a tether (not shown) therethrough. As also previously discussed, surfaces1242A and1242B are preferably smooth, or at least having a surface roughness that is less than that of the opposing surface(s), which may be defined by an inner surface or surfaces of outer coupling piece1250. As also previously discussed, inner coupling piece1240may comprise a slot1245that is shaped to match, or at least substantially match, the shape of the outer surface of a rod such that the rod may be firmly engaged/gripped by slot1245. In some embodiments, slot1245may comprise a plurality of teeth (not shown) or a contoured and/or roughened surface to further facilitate a firm engagement between the rod and inner coupling piece1240. Inner coupling piece1240further comprises a pair of opposing grooves, namely, grooves1244A and1244B, which may increase the flexibility of slot1245to allow for receipt of a rod therein by way of a snap-fit connection. In the depicted embodiment, grooves1244A and1244B comprise slits that terminate adjacent to slot1245. A perspective view of outer coupling piece1250is shown inFIG.14. As shown in this figure, outer coupling piece1250, like inner coupling piece1240, may comprise a slot1255that may be aligned with slot1245such that a rod (not shown) or another coupling member may extend through a slot defined by slots1245and1255. As also shown inFIG.14, opposing apertures1256A and1256B are formed in outer coupling piece1250such that a tether (not shown) may extend through the opposing passages previously mentioned and ultimately extend through opposing apertures1256A and1256B. Apertures1256A and1256B are formed in opposing shelves1259A and1259B of outer coupling piece1250. Shelves1259A and1259B may be configured to be aligned, or at least substantially aligned, with the top surface of inner coupling piece1240upon fully coupling outer coupling piece1250with inner coupling piece1240. Finally, as previously discussed, outer coupling piece1250further comprises two internal surfaces each having a plurality of projections1253, which may, in some embodiments, be defined by a series of parallel grooves, as previously described. These surfaces, together with outer surfaces1242A and12426of inner coupling piece1240, define two separate passages for receipt of opposing portions of a tether therethrough, as also previously described. The opposing surfaces that define these two passages, along with their respective surface features, are therefore another example of means for self-locking a tether within a rod-coupling assembly. FIGS.16-18depict still another embodiment of a tether clamping assembly1630that may be used in connection with a fixation assembly, such as a spinal fixation assembly. Tether clamping assembly1630is configured to receive two portions of a tether (not shown) therethrough so as to define a loop and tighten the loop around a spinal feature or other anatomical feature, as previously discussed. However, tether clamping assembly1630differs from the other coupling assemblies described herein in that tether clamping assembly1630is defined by a unitary structure rather than two separate structures coupled together. More particularly, tether clamping assembly1630comprises an internal structure defined by two locking members1651A and1651B. Locking members1651A and1651B are movably (in the depicted embodiment, pivotably) positioned in respective internal chambers so as to define empty spaces on either side. More particularly, locking members1651A and1651B are positioned in between respective inner spaces1657A/1657B and outer spaces1659A/1659B. In the depicted embodiment, opposing tether receiving paths are defined by outer spaces1659A/1659B, as best seen in the cross-sectional view ofFIG.18. Respective outer surfaces of locking members1651A and1651B may comprise a plurality of projections1653or may otherwise be surface roughened relative to the opposing inner surfaces1642A and1642B. Thus, both passages of coupling mechanism1630are configured to be self-locking with respect to tether portions received therethrough. In order words, upon extending respective tether portions through these passages and applying tension in the upward direction (relative to the orientation inFIGS.16and17), the tether portions retain the applied tension and are prevented, or at least inhibited, from being pulled in the opposite, downward direction. The opposing surfaces defining passages1659A and1659B, along with their respective surface features, are therefore another example of means for self-locking a tether within a rod-coupling assembly. Surface1642A, together with the surface upon which projections1653A are formed, define a first passage1659A for receiving a first portion of a tether, such as a flexible band, therethrough. Similarly, surface1642B, together with the surface upon which projections1653B are formed, define a second passage1659B for receiving a second portion of the tether therethrough. These passages have openings on opposite ends of tether clamping assembly1630, namely, upper openings1656A and1656B and respective lower openings1652A and1652B. Preferably, locking members1651A and1651B are pivotably movable within their respective chambers. Thus, outer spaces1659A/1659B may be configured, respectively, to allow locking members1651A and1651B to be resiliently biased towards the center of tether clamping assembly1630by a predetermined distance. Correspondingly, the width of the opposing passages defined in part by locking members1651A and1651B may be slightly increased as locking members1651A and1651B pivot in this manner. In addition, as depicted in the figures, respective base portions of locking members1651A and1651B may be narrowed to provide the flexibility to allow for this pivoting/movement. Because locking members1651A and1651B are movable, as previously discussed, preferably the friction differential between the opposing surfaces defining the passages are applied such that the surface on locking members1651A and1651B (the movable surfaces) have a greater surface roughness than the opposing non-movable surfaces. Thus, as previously mentioned, the projections1653may only be formed on these surfaces of locking members1651A and1651B and not on the opposing inner surfaces1642A and1642B of the inner chamber of tether clamping assembly1630. Tether clamping assembly1630further comprises release mechanisms to allow the self-locking feature to be unlocked. In the depicted embodiment, these release mechanisms comprise tether clamping assembly openings1658A and1658B which are positioned to allow access to respective locking member openings1654A and1654B formed in upper surfaces of locking members1651A and1651B. As best shown in the cross-sectional view ofFIG.18, openings1654A and1654B may be configured to receive portions of a suitable instrument, such as prongs. In some embodiments, this may allow a user to, for example, squeeze the locking members1651A and1651B towards one another and thereby release their respective locks on the tether portions extending through the tether passages extending between upper openings1656A and1656B and respective lower openings1652A and1652B. Of course, only one of the locking member openings1654A and1654B may be engaged, if desired, in order to only unlock the locking/clamping of tether clamping assembly1630on one tether portion instead of both portions extending through tether clamping assembly1630. Various methods for clamping a tether to a spinal feature or other anatomical feature may also be performed using one or more of the inventive clamping assemblies, or sub-elements of such an assembly, taught herein. For example, in some implementations of such methods, a tether, such as in some such implementations a flexible band, may be extended in a loop around an anatomical feature, such as around a spinal transverse process or spinal lamina, for example. An elongate member, such as a rigid rod, may be coupled with a clamping assembly, such as any of the various clamping assemblies disclosed herein. A first end of the tether may then be fed through a first passage of the clamping assembly. In some implementations, the first passage may be defined by a first pair of opposing surfaces having distinct surface roughnesses. In some such implementations, a movable surface (relative to the elongate member) may comprise a greater surface roughness that an opposing non-movable surface. Thus, for example, the movable surface may be formed with a plurality of grooves and/or projections to increase the surface roughness and/or grip on the tether. In some implementations, a second end of the flexible tether opposite from the first end may also be fed through a second passage, which may be defined by a second pair of opposing surfaces also having distinct surface roughnesses. In some implementations, the first end of the flexible tether may be fed through the first passage and/or the second end of the flexible tether may be fed through the second passage to automatically lock the flexible tether in place about the anatomical feature without the use of a secondary locking feature, such as a locking cap, set screw, or the like, to prevent a size of the loop from increasing. In some implementations, the clamping assembly may comprise an inner coupling piece and an outer coupling piece configured to receive the inner coupling piece. In some such implementations, the first passage and the second passage may be at least partially defined by an inner surface of the outer coupling piece and an outer surface of the inner coupling piece. In some implementations, the clamping assembly may also be unlocked following the self-locking procedure. For example, a user may unlock one or both tether portions using a means for unlocking a self-locking tether, such as the locking member openings1654A and1654B formed in upper surfaces of locking members1651A and1651B, for example. This may allow for readjustment or loosening of a tether clamping assembly following self-locking of the tether within the assembly. FIG.19is a perspective view of a spinal fixation assembly1900according to still other embodiments. Assembly1900comprises a tether1910that is configured to engage an anatomical feature, such as a spinal lamina, transverse process, and/or other spinal features in preferred embodiments. Tether1910in some embodiments, may comprise a flat, flexible band resembling, for example, a piece of tape. In preferred embodiments, tether1910may be flat and/or smooth on both opposing sides. For example, in preferred embodiments, tether1910may be devoid of locking teeth and/or other projections. Assembly1900further comprises a tether clamping assembly1930configured to engage and couple a coupling member, such as a cylindrical rod1920or another elongate member, with the tether1910so as to facilitate coupling of a patient's spine in a desired position without use of pedicle screws or other similar bone-invasive components. As further described below, tether clamping assembly1930comprises an inner coupling piece1940and an outer coupling piece1950configured to nestably engage the inner coupling piece1940, as depicted inFIG.19. Assembly1900further comprises a locking cap1960configured to engage tether clamping assembly1930. More particularly, in this embodiment, locking cap1960is configured to threadably engage a threaded shaft extending from inner coupling piece1940to pinch and thereby lock tether1910in place between cap1960and outer coupling piece1950. FIGS.20and21illustrate, respectively, a side elevation view and a corresponding cross-sectional view of assembly1900. As shown in these figures, opposing passages are defined for two portions of tether1910to allow for defining a loop and then clamping tether1910to lock the loop in place. These opposing passages are defined by various features of the two nestable coupling pieces, namely, inner coupling piece1940and outer coupling piece1950. More particularly, a first passageway for a first portion of tether1910is defined by a first inner surface (or, in alternative embodiments, a first portion of an inner surface) of outer coupling piece1950and an outer surface (or, in alternative embodiments, a first portion of an outer surface) of inner coupling piece1940. These passages are further defined by opposing apertures1943that are formed in opposing, protruding leg portions of inner coupling piece1940at one end and by opposing openings defined between a shaft portion1970of inner coupling piece1940and outer coupling piece1950. In preferred embodiments, clamping assembly1930is self-locking. In other words, by advancing tether1910through one or both of the aforementioned opposing passages, the tension on tether1910alone results in a tightening and/or at least partial locking of tether1910in clamping assembly1930without use of additional fasteners or fastening steps. Thus, although a locking cap1960is provided, in the depicted embodiment and other preferred embodiments, an at least partial locking in which a force differential between pulling the tether loop defined by tether1910in a locking direction and an unlocking direction opposite from the locking direction is provided such that tightening can be performed prior to coupling and/or tightening of cap1960. However, cap1960is preferably, and in the depicted embodiment is, configured to further seat and approximate the two coupling pieces and thereby further both lock the tether in place therebetween and lock the rod or another suitable longitudinal and/or coupling member seated in the clamping assembly. In the depicted and other preferred embodiments, no additional instruments, and/or no other forces (such as manual tension) is required in order to maintain tension on the free ends of the tether to lock the tether in place. In other words, unlike prior art systems for clamping a tether, which often require complicated, bulky, and expensive instruments to maintain tension while locking, simply applying tension to the loop by extending the tether in the locking direction through the one or more passages to tighten the loop will automatically lock the tether in place and maintain the tension. This automatic, self-locking feature, in preferred embodiments and implementations, is therefore expected to result in decreased surgery time, decreased use of various tensioning instrumentation, and likely decreased costs and improved results. The accompanying figures further illustrate that inner coupling piece1940defines a slot1945for receipt of a rod1920or other elongate and/or rigid coupling member therethrough. Preferably, slot1945is shaped to match, or at least substantially match, the shape of the outer surface of rod1920such that rod1920may be engaged/gripped by slot1945. In some embodiments, slot1945may comprise one or more engagement features, such as teeth, grooves, spikes, or a contoured and/or roughened surface to further facilitate a firm engagement between rod1920and inner coupling piece1940. In some embodiments, one or both of the coupling pieces may comprise features that allow for resilient receipt of rod1920therein, such that rod1920may be snapped and locked (at least from a translation standpoint; longitudinal movement may be allowed after locking in some embodiments) in place. Thus, in the depicted embodiment, inner coupling piece1940comprises opposing ledges1941that may be curved to match the curvature of rod1920. It may also, or alternatively, be desired to provide a ledge1941with an edge that may be the most, or only, point of direct contact with rod1920to bite into rod1920and lock it in place. This edge can be best seen inFIG.22. In the depicted embodiment, these ledges1941comprise partial ledges that are positioned on opposite sides both from the perspective of the dimension of inner coupling piece1940corresponding to (parallel to) the elongated axis of rod1920and in the direction perpendicular to this direction across the width of rod1920, as shown inFIG.22. The presence of such one of more ledges1941may facilitate a secure coupling of rod1920, in some cases by way of a snap-fit engagement. Thus, it may be preferred to allow the opposing arms of inner coupling piece1940defining outer surfaces1942to be slightly flexible to allow for expanding to receive rod1920, but preferably resiliently flexible to allow for resuming its previous shape and/or size to grip rod1920. Of course, alternative embodiments are contemplated in which this ridge extends the entire length of the opposing legs of inner coupling piece1940or is omitted. A desired coupling of rod1920may also be provided by providing for a certain amount of flexibility in the opposing legs of inner coupling piece1940. In the depicted embodiment, this may be provided for, at least in part, by making the central hub portion of inner coupling piece1940from which the opposing legs extend have a narrower width than the portions of the legs that define apertures1943, as also shown inFIG.22. Apertures1943may be provided to guide the tether into the clamping features of the assembly1930and to prevent or at least inhibit twisting and/or misalignment of the tether. Thus, in embodiments utilizing a tether have a rectangular shape in cross-section, as show in the accompanying figures, apertures1943may define slots having a similar shape and may therefore be referred to herein as “tether guide slots.” In some embodiments providing a snap-on feature, slot1945may also be roughened, textured, and or provided with teeth or other engagement features, as mentioned above. At the upper end (from the perspective ofFIG.22) of inner coupling piece1940, a shaft1970extends from the portion of inner coupling piece1940defining the outer surfaces1942that partially define the opposing passages for tether1910. Shaft1970comprises a frangible or weakened portion1975. This may allow for the upper portion, which may facilitate coupling of cap1960, to be removed during surgery by breaking shaft1970at weakened portion1975. Shaft1940further comprises a lower coupling portion1976, which is preferably threaded, along with an upper coupling portion1974, a portion of which may also be threaded. Shaft1940may therefore serve as a guidepost for coupling of various elements of assembly1930, including outer coupling piece1950and cap1960. This may allow for cap1960to be threaded onto the portion of inner coupling piece1940that is to remain within the patient's body following the procedure by providing a starting point above the weakened region1975. Of course, rather than providing a weakened region, in alternative embodiments, a guide post may be provided with other features that may be removable to allow for removal of the upper portion/guide post portion of the assembly following coupling of a cap and/or other elements of the assembly. For example, in other embodiments, an end of upper coupling portion1974may be threaded and may fit within a female threaded portion of lower coupling portion1976, or vice versa. As another alternative, in some embodiments a snap-fit coupling or other means for removable coupling may be provided. FIG.23is a perspective view of outer coupling piece1950separated from the other elements of assembly1900. As best seen in this figure, outer coupling piece1950, like inner coupling piece1940, comprises a slot1955that may be configured to be aligned with slot1945upon coupling inner coupling piece1940with outer coupling piece1950. Also, by coupling inner coupling piece1940with outer coupling piece1950, a pair of opposing passages are defined for receipt of separate portions of a flexible tether1910therethrough, as previously mentioned. The upper portion of outer coupling piece1950comprises an opening1957that is configured to receive shaft1970of inner coupling piece1960therethrough. Because tether1910exits adjacent this opening, the depicted embodiment further comprises opposing pairs of grooves1959, both of which define paths for receipt of tether1910. In other words, the width of tether1910may at least substantially match the distance between adjacent grooves1959on both sides of outer coupling piece1950so that the ends (perpendicular to the length) of tether1910fit within grooves1959. Grooves1959may also prevent or at least inhibit lateral translation of the tether1910as the locking cap1960, if present, is tightened. Grooves1959may at least substantially the width of the tether1910, as described above, but the portion of the upper surface of outer coupling piece1950in between these grooves1959may also be recessed relative to the opposing rims of outer coupling piece that face each other in a direction perpendicular to the direction of tether1910, as shown inFIG.23. This may prevent over-compression of tether1910when cap1960is applied and/or may provide for increased control of the tether clamping that may take place therein. Outer coupling piece1950further comprises a notch1954, which may be configured to engage a corresponding protruding element of a suitable surgical instrument. Although not visible inFIG.23, in some embodiments, a similar notch may be formed on the opposite side of outer coupling piece1950. Preferably, clamping assembly1930is configured such that tether1910can be clamped and/or locked in clamping assembly1930so as to allow tether1910to move through one or both opposing passages in a first direction to lock the tether in place but so as to prevent, or at least substantially prevent and/or provide a force differential, tether1910from moving through one or both passages in a second direction opposite from the first direction. Thus, with respect to the view ofFIGS.20and21, tether1910may be advanced in an upward direction along both opposing passages, thereby resulting in a tether loop that gets smaller to apply a force to a spinal or other anatomical feature, but may be prevented, or at least relatively inhibited from being advanced in a downward direction to enlarge the size of this tether loop. In some embodiments, the greater the force applied in a locking direction, the tighter the lock, and therefore the more difficult it is to move the tether in an opposite direction from the locking direction. Moreover, in some embodiments, this locking/force differential may be applied without use of cap1960or any other locking feature/step. In some embodiments, this self-locking feature may be enhanced by providing a friction differential between the two opposing surfaces through which one or more portions of tether1910are received. Preferably, this friction differential is applied such that a movable surface has a greater surface roughness than an opposing non-movable surface. Because, as discussed in greater detail below, in some implementations of inventive methods disclosed herein, the inner coupling piece1940may be coupled with a rod1920or other elongate member prior to coupling outer coupling piece1950with inner coupling piece1940, outer coupling piece1950may be considered the “moveable” element of clamping assembly1930. In the depicted embodiment, however, the aforementioned locking/force differential may be provided without providing the friction differential described above. For example, the embodiment depicted inFIGS.19-23provides for self-locking of tether1910by virtue of a wedge-locking feature. This locking feature is preferably provided, and with respect to the depicted embodiments is provided, by simply applying increased tension to the loop end of the tether1910by extending one or both free ends of the tether1910through assembly1930, which may take place by simply pulling the tether against assembly1930to shorten the loop around an anatomical feature to increase the tension on the loop end. Simply releasing the free end or ends of the tether1910then automatically locks the tether1910in place. Similarly, loosening/unlocking may be provided by simply applying increased tension to the free end or ends of the tether1910relative to the loop end to temporarily release the lock and allow the tether1910to extend through the clamping features of assembly1930in the unlocking direction. Assembly1900further comprises a dual-locking feature, namely, it is configured to provide simultaneous locking of tether1910and locking/tightening of the grip on rod1920. This may be provided in part due to the wedging of outer coupling piece1950onto inner coupling piece1940. Thus, as the tension on tether1910is increased in the tightening direction by pulling one or both ends of tether1910through the two opposing passages defined by outer coupling piece1950and inner coupling piece1940, not only is tether1910pinched more tightly therebetween to prevent it from being loosened, but, at the same time, the slot1945created by the inner surface of inner coupling piece1940is squeezed against the rod1920more tightly to further lock the tether clamping assembly1930in place with respect to the rod1920. This feature is provided for by virtue of the wedge lock previously described, in which two tapering surfaces are wedged against each other (with the tether1910therebetween) in combination with making the inner coupling piece1940flexible so that the size of slot1945can vary to facilitate this compression. Preferably, as shown inFIGS.19and20, these tapering surfaces are frusto-conical surfaces. Assemblies1900and1930may also be configured to facilitate loosening of the grip/lock/clamp on the tether1910for readjustment. As previously mentioned, locking of the tether may be accomplished automatically by engaging the tether1910between the opposing surfaces of the inner coupling piece1940and the outer coupling piece1950and pulling the tether1910in the locking direction with an opposite force on assembly1930to decrease the size of the tether loop, with the optional cap1960to further enhance this locking of the tether1910and/or the rod1920once a desired force and/or position of the assembly has been achieved. This may allow for sequential tightening of various elements of a spinal fixation system without leaving instrumentation in place while moving to a new location within the system, which may also reduce the instrument tray and decrease surgery time. In some embodiments, including those depicted in the accompanying figures, the automatic locking, which may take place without tensioning instrumentation due to the features described herein, may take place not only on the tether1910but also simultaneously on the rod or other longitudinal member. If loosening is needed, in preferred embodiments, due to the unique features described herein, the tether may be loosened by simply pulling or otherwise tensioning one or both of the free ends of the tether, which loosens the grip on the tether and allows it to pass through the one or more passages described herein in the unlocking direction. In the event that the clamp provided by the inner and outer coupling pieces is too tight, such as when a locking cap/nut has been applied, in some embodiments and implementations, the outer coupling piece1950may be separated from the inner coupling piece1940to allow for loosening using suitable instrumentation. FIG.19further illustrates how approximation of inner coupling piece1940and outer coupling piece1950results in laterally pinching of the portion of inner coupling piece1940within which rod1920sits. Thus, as explained elsewhere herein, the approximation of inner coupling piece1940and outer coupling piece1950results in simultaneous clamping of tether1910and rod1920. In the depicted embodiment, direct contact and therefore fixation and/or locking of rod1920or another longitudinal member is provided by not only inner coupling piece1940but also outer coupling piece1950. Indeed, as further illustrated inFIG.23, a pair of projections or ridges1958may be provided within slot1955of outer coupling piece1950, which may prevent or at least inhibit rotation of rod1920. In some embodiments, ridges1958or another similar feature may only be configured to provide a torsional locking at the time that the tether1910is locked in placed. Thus, the torsional locking force may be proportional to the locking force on the tether1910and may be increased automatically by increasing the locking force on tether1910, by way of simply pulling the tether in the locking direction, as described above, and/or by way of applying a final locking element, such as locking cap1960. By providing for lateral contact/force with rod1920via ridges1941of inner coupling piece1940and upper contact/force with rod1920by way of projections1958on outer coupling piece1950, the approximation of inner coupling piece1940and outer coupling piece1950may provide for locking that, like the locking on the tether1910, increases automatically as the tension on the loop end is increased. As also illustrated inFIG.23, a groove1953may be provided along one or more opposing inner surfaces of outer coupling piece1950to provide a path/seat for a tether. The protruding surfaces1956sitting above these grooves provide a surface for direct contact with an outer surface of inner coupling piece1940, as best illustrated inFIG.19. This allows the outer coupling piece1950to compress the inner coupling piece1940as the two coupling pieces are wedged and nested together. These surfaces may be part of and/or continuous with the surfaces defining the passages previously mentioned, as shown in the drawings. In alternative embodiments, however, they may be entirely distinct surfaces. By providing a feature, such as ledge1941, that serves as a lower stop to the rod1920, the rod1920may be prevented from being pushed out the bottom of slot1945as outer coupling piece1950is squeezed against inner coupling piece1940. FIG.24is a perspective view of cap1960of spinal fixation assembly1900according to some embodiments. Cap1960comprises a flanged portion1964, which is configured to pinch a portion of tether1910against an upper surface of outer coupling piece1950. Cap1960further comprises a female threaded opening1962configured to engage the threads of shaft1970of inner coupling piece1940. The upper surface of cap1960comprises a keyed feature defined by a plurality of circumferentially-spaced grooves that may be configured to receive corresponding prongs of a driver or other similar instrument. A rim1963extends from the lower surface of cap1960. Rim1963may be configured to seat within the periphery of the upper opening provided in outer coupling piece1950, as best illustrated inFIG.21. Rim1963may also allow for extending the threads provided on cap1960to prevent or at least inhibit the threads from stripping. The step provided by rim1963may also allow tether1910to extend through a corner defined by rim1963and outer coupling piece1950to increase the gripping force provided therein without excessive pinching, which may otherwise result in cutting and/or fraying of the tether fibers. As previously mentioned, a portion or, in some such embodiments including the embodiment of assembly1900, two opposing portions of tether1910may be clamped in between flanged portion1964of cap1960and another portion of assembly1930, such as the opposing ledges extending in between grooves1959on opposing sides of outer coupling piece1950. Thus, cap1960is another example of secondary means for locking a tether within a rod-coupling assembly. Cap1960may also serve the function of establishing and/or increasing the lock on the rod and/or tether and/or decreasing the possibility of unwanted loosening/disassembly. More particularly, because cap1960pulls inner coupling piece1940and outer coupling piece1950together, cap1960may increase the clamping force on tether1910and, in some embodiments including the depicted embodiment, may simultaneously increase the clamping force on the rod and/or another longitudinal member. The foregoing specification has been described with reference to various embodiments and implementations. However, one of ordinary skill in the art will appreciate that various modifications and changes can be made without departing from the scope of the present disclosure. For example, various operational steps, as well as components for carrying out operational steps, may be implemented in various ways depending upon the particular application or in consideration of any number of cost functions associated with the operation of the system. Accordingly, any one or more of the steps may be deleted, modified, or combined with other steps. Further, this disclosure is to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope thereof. Likewise, benefits, other advantages, and solutions to problems have been described above with regard to various embodiments. However, benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced, are not to be construed as a critical, a required, or an essential feature or element. Those having skill in the art will appreciate that many changes may be made to the details of the above-described embodiments without departing from the underlying principles of the invention. The scope of the present inventions should, therefore, be determined only by the following claims.

11857222

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the disclosure are generally directed to bone fastener devices, assemblies, systems, and methods for securing a bone fastener and/or spinal rod. Specifically, embodiments are directed to tulip assemblies configured to secure the spinal rod to the bone fastener. Although described with reference to the spine, it will be appreciated that the devices and systems described herein may be applied to other orthopedic locations and applications, such as trauma. Additional aspects, advantages and/or other features of example embodiments of the invention will become apparent in view of the following detailed description. It should be apparent to those skilled in the art that the described embodiments provided herein are merely exemplary and illustrative and not limiting. Numerous embodiments of modifications thereof are contemplated as falling within the scope of this disclosure and equivalents thereto. Referring now toFIGS.1-5, an orthopedic fixation device, implant, or bone fastener assembly10is shown according to one embodiment. The implant or bone fastener assembly10may include a modular tulip element or tulip head12attachable to a bone fastener14. The modular tulip12may be top loaded intra-operatively onto the bone fastener14. The tulip head12is also configured to receive a locking cap16to secure a spinal rod18therein. For a polyaxial bone fastener14, tightening the locking cap16compresses the rod18into the tulip head12, thereby restricting motion of the bone fastener14and forming a rigid construct. With further emphasis onFIG.2, the tulip head12extends from an upper surface or top20to a lower surface or bottom22along a central longitudinal axis. The tulip head12may include a base or body24and arms26that extend upwardly from the body24. The arms26may be aligned generally in parallel with one another. A central bore28may extend through the body24of the tulip head12. The opposed arms26may define a U-shaped channel or rounded rod slot30, transverse to the bore28. The rounded rod slot30is sized and configured to accept the rod18perpendicular to the threads of the locking cap16. Each of the arms26has an interior surface32having a threaded portion34for engaging the locking cap16. Each of the arms26may include an outer surface36with one or more features for engagement with mating instruments. For example, instruments (such as instruments230,250,260) may engage with these features to constrain the instrument axially to the tulip head12. Each of the arms26may include a tool engagement groove38formed into the outer surface36, which may be used for holding the tulip head12with a suitable tool. The groove38may include a cylindrical groove cut into the tulip head12with an inward facing top surface46. The inward facing top surface46may have an inclined face that slopes such that it is lower toward the outer surface36and higher as the sloped surface46extends inward. An overhang48may form a bottom facing surface pointed toward the top facing surface46. The bottom facing surface of the overhang48may also be slanted or sloped. For example, the bottom facing surface of the overhang48may have the same or similar slope to the upward facing surface46. The annular groove38may form an upper dovetail configured for engaging with the instrument. The inward angle of the upper dovetail38may prevent the instrument from disengaging by directing forces on the instrument inward and maintaining engagement. Each of the arms26may include a tower pocket40configured to engage with mating instruments to constrain rotation of the instrument to the tulip head12. The tower pockets40may include slots adjacent to the rod slot30. For example, a vertical slot may be provided along an upper portion of each side of the arms26. The outward surfaces of the pockets40are configured to contact corresponding surfaces on the instrument, thereby preventing splay and disengagement of the instrument from the tulip head12. The upper dovetail38and tower pockets40may be combined to fully constrain the instrument to the tulip head12. The outer surface36of each arm26may also define a ball hole or rocker hole42. The rocker holes42may interrupt the engagement groove38, for example, at a central position on each arm26. The rocker holes42may be cylindrical or obround pockets which allow engagement of a rocker-style instrument with pin features, allowing rotation of the instrument within the holes42. Rotation about the rocker holes42allows the user to lever and reduce the rod18into the head12. In addition, front and back surfaces44of the tulip body24may be flat or planar. The flats44may be positioned on opposite sides of the tulip body24, for example, below the rod slot30. The flats44may act as an additional counter-rotation feature when engaged with an instrument. The rod18may be secured in the tulip head12with the locking cap16. The locking cap16may include a body with an upper surface50, a lower surface52, and an outer body54defining a threaded portion56. As shown inFIG.1, the locking cap16may be in the form of a set screw with a drive feature or recess58defined in the upper surface50configured to be engaged by a driving instrument, which is able to insert and tighten the locking cap16in the tulip head12. The recess58may be a hexalobe, slot, cross, or other suitable shape that may engage with a tool or device having a corresponding tip. The recess58may extend partially into the body of the locking cap16or entirely through the locking cap16. The bottom52of the locking cap16may be flat or otherwise configured to ensure desired contact with the rod18. The external threaded portion56of the locking cap16may have a thread geometry configured to secure the locking cap16to the tulip head12. The external threaded portion56of the locking cap16may extend between the upper and lower surfaces50,52. The internal threads34within the head12mate with external threads34of the locking cap16. Tightening the locking cap16compresses the rod18into the head12and internal components, thereby restricting motion of the screw14and forming a rigid construct. In one embodiment shown inFIG.3, the threads34,56of the locking cap16and tulip head12may be configured to intermesh to prevent or reduce splaying of the arms26of the tulip12. In one embodiment, the interior threads34of the tulip12have a downward projecting hook60and the exterior threads56of the locking cap16have a corresponding upward projecting hook62. It will be appreciated that these orientations may be reversed. When threaded together, the downward and upward hooks60,62form inward-facing surfaces, which point toward one another at each level of engagement. The inward-facing surfaces60,62may be vertical or slightly angled out for ease of manufacturing. The threads34,56may each define a contacting surface64where the opposite hook60,62is receivable when threaded together. For example, the cap16may have a contacting top surface64and the tulip12may have a contacting bottom surface64, which receive the respective hooks60,62. The contacting surfaces64may be horizontal or slightly angled out. Corner radii may be added to each outer and inner corner of the threads34,56to prevent edge loading and for ease of manufacturing. The flank surface66of the threads56may be angled outward to increase the root height of the threads56for strength or may be horizontal. The thread profile may provide for increased splay resistance, strength, and resistance to cross-threading of the locking cap16in the tulip head12. The anti-splay features in the thread geometry and angular profile of the threads may prevent or minimize mis-engagement. When tightened, an upward force is exerted on the bottom of the locking cap16by the rod18, causing the top surface64of the threads56to come into contact. As the tightening torque increases, significant forces are developed within the threads34,56, which may cause the tulip12to deflect outward and begin to splay. In the embodiment shown, the inward-facing surfaces60,62of the external threads56of the locking cap16and internal threads34of the tulip12contact after the tulip12begins to splay. These inward-facing surfaces60,62develop forces which counter the splaying action and prevent further splay. The locking cap16may include any suitable thread geometry, for example, to improve strength, reduce outward splaying forces on the tulip head12, increase resistance to cross-threading, allow quick engagement of the locking cap16, and/or maintain a more consistent interface with mating instruments. The bone fastener14may include a bone screw, anchor, clamp, or the like configured to engage bone. In one embodiment, the bone fastener14is a bone screw, such as a pedicle screw, having a screw head80and a threaded shaft82extending from the screw head80. The figures do not show the distal end of the threaded shaft82, but suitable bone fasteners14will be recognized by those of ordinary skill in art. Examples of bone fasteners, other implants, and rod constructs are described in more detail, for example, in U.S. Pat. No. 10,368,917, which is incorporated by reference herein in its entirety for all purposes. It will be appreciated that the threaded shaft82may have a number of different features, such as thread pitch, shaft diameter to thread diameter, overall shaft shape, and the like, depending, for example, on the particular application. While the screw head80may have any general shape, in the case of a polyaxial fastener14, at least a portion of the screw head80may have a curved surface in order to allow for rotational movement and/or angular adjustment of the bone fastener14with respect to the tulip head12. For example, at least a portion of the screw head80may be shaped to form a portion of a ball or at least a portion of a sphere. The screw head80may have a tool engagement surface84that can be engaged, for example, by a screw-driving instrument or other device. In one embodiment, the bone screw head80has a hexalobe recess84for driving the screw14into bone. It will be appreciated that any suitably shaped tool engagement surface84may be provided. Turning now toFIG.4, an exploded view of a modular tulip assembly10is shown according to one embodiment. The modular tulip assembly10includes tulip head12, a saddle90, a bearing washer92, a shear clip94, and a support clip96. The tulip head12houses all of the components90,92,94,96. The modular tulip assembly10may be top loaded intra-operatively onto the bone fastener14. The spinal rod18may be secured into the tulip head12with the locking cap16. The saddle90applies compressive force to the bone screw14and restricts its angulation when the rod18is tightened to the implant10with the locking cap16. The saddle90may have an upper surface102, a lower surface104, an outer surface106, which may be curved or rounded, and a bore108defined through the saddle90. A lower portion of the bore108may be rounded and sized to receive an upper portion of the screw head80. A rod slot or seat110may be defined in the upper surface92of the saddle90. The rod slot or seat110may be configured to receive a bottom portion of the rod18therein. The rod seat110may be generally aligned with the rod slot30through the tulip head12. The saddle90may include one or more external recesses or channels112. For example, the saddle90may include two opposed, recessed channels112positioned near the top of the saddle90. The saddle90provides a collar about an upper portion of the screw head80. The polyaxial motion of the screw14is locked when the locking cap16is threaded downwardly, compressing the rod18onto the saddle90, which thereby compresses against the spherical head80of the bone screw14. The bearing washer92centers the shear clip94within the tulip head12to limit translation of the shear clip94within the tulip head12, while also providing friction against the bone screw head80for memory. The bearing washer92may be housed in an internal groove in the tulip12and positioned around the bottom of the saddle90. The bearing washer92, saddle90, and tulip head12may be coaxially aligned. The bearing washer92may include a split ring116with a central through opening and a wide cut in fluid communication with the central through opening. The bearing washer92includes a radial neck118protruding outward from the split ring116. One or more slits120may be defined through the top of the neck118downward into the split ring116. The slits120may be rounded with a circular or semi-circular cross-section. In the embodiment shown, three slits120are provided equally around the ring116although any suitable location and number of slits120may be provided. The shear clip94retains the bone screw14within the assembly10and resists compressive force exerted down on the bone screw14. The shear clip94is a breakable component configured to fracture when enough force is placed on the shear clip94. Due to its breakable nature, the shear clip94has different forms throughout the procedure. During the initial assembly, the shear clip94is in an initial solid form. After the screw head80is forced through the shear clip94, the shear clip breaks and is radially expanded to accommodate the head80of the screw14. After breaking, the shear clip94collapses, acting like a spring around the screw head80, and falls into its final position to secure the screw head80to the tulip head12. In its initial state, the shear clip94may be positionable in an internal groove in the tulip12and located around the split ring116of the bearing washer92. As a solid member, the shear clip94may include a full ring122with a central through opening. The shear clip94is axially aligned with the tulip12, the saddle90, and the bearing washer92. The shear clip94may include a lower annular ring124defining a groove along an outer surface and a rim along an inner surface of the clip94. The inner rim of the lower annular ring124may define a seat126with the body of the clip94, which is permitted to translate along the split ring116of the bearing washer92. The shear clip94may define a fracture site configured to break upon application of a force. In one embodiment, one or more partial slits128may be defined through the body of the ring122. The slits120may be rounded with a circular, semi-circular, and/or obround cross-section, for example. The slits120may be vertically aligned to form a temporary bridge portion130completing ring122in its solid form. For example, the temporary bridge130may be a thin strip of material continuous with the material of the ring122, which is configured to break when enough force is applied. In the embodiment shown, two aligned slits130are shown to define a single temporary bridge130through the clip94although any suitable location and number of slits130and/or bridges130may be provided. After a suitable force is applied to the shear clip94during use, the bridge portion130breaks, thereby separating the full ring122into a split ring. In this manner, the shear clip94may allow for three distinct states of bodies: solid (initial form), expanded (after breaking), and collapsed (around screw head80), which allow for stronger head assembly and disassembly. The support clip96may be provided to retain the shear clip94within the head12of the modular tulip assembly10. The support clip96may be axially aligned with the tulip12, the saddle90, the bearing washer92, and the shear clip94. The support clip96may be positionable in an internal groove at the bottom of the tulip head12and located around the annular ring124of the shear clip94. The support clip96may include a split ring132with a central through opening and cut in fluid communication with the central through opening. The support clip96may include a lower annular ring134defining a groove along an outer surface and a rim along an inner surface of the clip96. The inner rim of the lower annular ring134may define a seat136within the body of the clip96, which is permitted to translate along the annular ring124of the shear clip94. As best seen inFIGS.5A-5E, the modular tulip10may be assembled to the top of the bone screw14intra-operatively. It will be appreciated that the shaft of the bone screw14is omitted for clarity. With reference toFIG.5A, before the head80of the bone fastener14is loaded into the bottom of the tulip12, the support clip96rests in the bottom of the tulip head12. The annular ring124of the shear clip94rests in the seat136of the support clip96. The temporary bridge130of the shear ring94is fully intact. The bearing washer92sits above the shear clip94. The saddle90rests above the shear clip94.FIG.5Ashows the screw head80beginning to pass through the bottom of the tulip12, through the support clip96, and into contact with the shear clip94.FIG.5Bshows the screw head80pushing the shear clip94upward until the shear clip94tops out on the bearing clip92. In this manner, the shear clip94lifts out of the support clip96, and the split ring116of the bearing washer92is received into the seat126of the shear clip94. With emphasis onFIG.5C, when enough upward pressure or force is placed on the shear clip94, the shear clip94fractures at known site130, allowing the shear clip94to expand and accept the bone screw head80. The shear clip94surrounds the head80of the fastener14. The shear clip94expands radially outward leaving a gap between the seat126and the ring116of the bearing washer92.FIG.5Dshows the screw head80as it continues to travel upwardly into contact with the bottom of saddle90. The shear clip94then collapses as a spring around the screw head80and falls in place to the internal diameter of the support clip96by following the position of the bearing clip92. As shown inFIG.5E, the annular ring124of the broken and collapsed shear clip94rests in the seat136in the support clip96and presses against the screw head80. The top of the broken ring122of the shear clip94presses against the split ring116of the bearing washer92. The saddle90translates downward and is positioned around the top of the screw head80. The saddle90may be located between the top of the bearing washer92and the screw head80. The broken and collapsed shear clip94is configured to accept the load of the screw head80and saddle90when loaded by rod18via locking cap16. Turning now toFIGS.6-9, a modular tulip assembly210for retaining screw head80and spinal rod18is shown according to another embodiment. Tulip assembly210is similar to tulip assembly10except the internal components include a saddle214and clip216to retain the bone fastener14. Similar to tulip12, tulip head212has many of the same features including opposed arms26defining U-shaped rod slot30configured to accept the rod18, interior threaded portions34for engaging the locking cap16, and one or more outer engagement features38,40,42, for interaction with mating instruments. The modular tulip assembly210also features a flat surface44on opposing sides of the tulip assembly. The saddle214includes an upper surface for receiving the rod18and a bottom surface for receiving the top of the screw head80. The clip216may include a loop, ring, split-ring, snap ring, or other suitable retaining ring. In an exemplary embodiment, the clip216is a split retaining clip. The inner bore218defines a first upper portion220above a second lower portion222. The saddle214is housed within the upper portion220and the clip216is housed within the lower portion222with excess clearance to allow them each to travel along the central axis of the tulip212. The upper portion220may include a modular bump224configured to interface with a corresponding recess in the saddle214. For example, when the saddle214is in a fully upward position, the inner bump224is receivable in the corresponding radial recess around the saddle214, thereby securing the saddle214in the tulip head212. The lower portion222that the clip216is housed within may taper such that the bottom of portion222has minimal clearance over the clip216while the top of portion222has additional clearance. In one embodiment, the outer surface of the clip216and the inner surface222of the tulip212is conically tapered. In an alternative embodiment, the outer surface of the clip216is spherically tapered, and the recess222in the inner surface of the tulip212has two radiused tapers so that the clip216can angle or tilt with the screw14. With further emphasis onFIGS.7A-7B, the saddle214and clip216may be assembled into the tulip head212, for example, through the bottom22of the tulip head212. As shown inFIG.7A, assembly may involve insertion of the saddle214from the lower portion of the tulip head212and into bore220. As shown inFIG.7B, the saddle214is raised past modular bump224so that the saddle214is retained in an upward position. The split retaining clip216is then inserted into the groove222in the lower portion of the tulip head212. Turning now toFIGS.8A-8C, modular screw insertion is shown according to one embodiment. As shown inFIG.8A, when the spherical head80of the modular screw14is inserted into the lower bore of the tulip212, the head80contacts the bottom of the clip216and moves the clip216to the upper portion of the clip groove222. As shown inFIG.8B, further insertion of the spherical head80expands the clip216. The additional clearance of the groove222allows the clip216to expand until the center of the spherical head80of the screw14has passed through the clip216. The saddle214is positioned in its modular bump224with sufficient clearance above the clip216to allow the travel of the spherical head80of the screw14. As shown inFIG.8C, once the clip216passes the center of the spherical head80of the screw14, the modular tulip head212has been assembled to the screw14. Forces directed to dissociate the screw14from the modular tulip head212translate the clip216down against the smaller portion of the groove222in the modular head212, which prevents the clip216from expanding to prevent the screw14from disassembling from the modular tulip head212. The saddle is then depressed past the modular bump (as seen inFIG.9) to further prevent the screw and clip from moving back up and releasing the screw head. FIG.9depicts angulation of the screw14relative to the modular tulip head212. In this embodiment, the modular clip216and corresponding groove222in the tulip head212have a spherical profile which allows the clip216to angle with the screw head80, thereby allowing additional angulation. As shown, the screw14and clip216are angled off-axis, thereby providing for polyaxial movement of the screw14relative to the modular tulip head212. The head assembly and modular head insertion include a simple design easily manufacturable with robust features. The modular bump224adds additional security to prevent inadvertent disengagement of the implant210and the spherical clip216allows additional angulation of the screw head14. Turning now toFIGS.10-13, one or more instrument interfaces may be used for engagement with one or more instruments, such as insertion, positioning, reduction, derotation, compression, distraction and/or other holding instruments. The instrument interfaces allow one or more instruments to fully or partially constrain or attach to the implant, provide increased holding strength, decrease splaying forces which may cause disengagement of the instrument, reduce and lever the rod into position, and/or simplify manufacturing. In one embodiment, the annular or cylindrical groove38defined into the outer surface36of the tulip head12,212provides for engagement of insertion, reduction, derotation, or other holding instrument230. As shown inFIG.10, holding instrument230may include a distal tip232for engaging the proximal end of the tulip head12,212. The instrument230may have a body or sleeve234configured to receive the top of the tulip head12,212and a pair of inner arms236with distal prongs238. The prongs238may point toward one another with angled surfaces configured to interface with the groove38in the tulip head12,212. The interaction between prongs238and groove38may form a dovetail connection to constrain the instrument230axially to the tulip head12,212. The inward angle may help to prevent disengagement of the instrument230under load by directing forces inward and toward the central axis of the tulip head12. In one embodiment, a plurality of tower pockets40are defined into the sides of the arms26to prevent splay and disengagement of the instrument230from the tulip head12,212. As shown inFIG.11, the sleeve234of the holding instrument230may include a plurality of protrusions240configured to engage with the respective tower pockets40. For example, the sleeve234of the holding instrument230may include a first pair of inwardly facing protrusions240configured to slidably engage with the first arm26and a second pair of inwardly facing protrusions240configured to slidably engage with the second arm26of the tulip head12,212to constrain rotation of the instrument230relative to the tulip head12,212. The outward surfaces of the pockets40contact corresponding surfaces on the instrument230, thereby further preventing splay and disengagement of the instrument230from the tulip head12,212. In one embodiment, a pair of rocker holes42are defined into the sides of the arms26of the tulip12,212to lever and reduce the rod18into the tulip head12,212. As shown inFIG.12, a rocker instrument250may include a pair of arm portions252positionable on opposite sides of the arms26of the tulip head12,212. The distal end of each arm portion252includes pin254receivable in the rocker holes42. The pins254may point inwardly toward one another to engage with the rocker holes42, thereby allowing for rotation of the instrument250within the rocker holes42. Inner segments of the arm portions252include rocker cam surfaces256configured to contact the rod18. The arm portions252are configured to grasp the sides of the tulip head12,212with the rocker cam256positioned above the rod18and then lever backward over the rod18. The levering action forces the rod18to seat into the saddle90,214of the implant10,210. Thus, the rod18may be levered and reduced into the tulip12,212via engagement of the rocker-style instrument250and rotation about the pivot axis of the rocker holes42and pins254. In one embodiment shown inFIGS.13A-13B, a head inserter instrument260may engage the tulip head12,212for insertion. The insertion instrument260may include a pair of opposed arm members262with distal prongs264, similar to prongs238, configured to interface with the groove38in the tulip head12,212. The arm members262and prongs264are configured to grasp the sides of the tulip head12,212. The interaction between prongs238and groove38may form a dovetail connection to constrain the instrument260axially to the tulip head12,212and prevent disengagement of the instrument260. As best seen inFIG.13B, the insertion instrument260may include a displacing pin266positioned between the arm members262and centered along a central longitudinal axis of the instrument260. The displacing pin266is moveable axially through the arms262and is configured to sense the full insertion by contact with the top of the screw head80. The sensing of the screw insertion unblocks the actuation of the instrument260, which permits a pusher268to displace downward and depress the saddle214past the modular bump224. The pusher268may include a pair of pusher blades oriented 90° relative to arms26and configured to fit in the gap therebetween. The pusher268restricts the screw head80and clip216from translating upward to prevent the clip216from expanding and releasing the screw head80while the inserter instrument260is attached. The instrument engagement features may help to prevent instrument disengagement under high loads while maintaining a low instrument and implant profile away from bony anatomy. Turning now toFIGS.14A-14B, the tulip head12,212may also be applied to other screw designs, such as uniplanar and monoaxial screws.FIGS.14A-14Bshow one embodiment of a uniplanar screw assembly310(a close-up exploded view and cross-sectional view is shown with the distal end of the screw shaft omitted for clarity). In this embodiment, the uniplanar pedicle screw assembly310allows for angulation in one direction but not the other direction. The uniplanar movement allows the application of forces through the screw rigidly for correction of spinal deformities. Similar to the polyaxial screw assembly210, the uniplanar screw assembly310includes a tulip head312, a saddle314, and a clip316for retaining the screw head80of a uniplanar screw. Tulip head312has many of the same features as tulips12,212including opposed arms26defining U-shaped rod slot30configured to accept the rod18, interior threaded portions34for engaging the locking cap16, and one or more outer engagement features38,40,42,44for interaction with mating instruments. The tulip head312provides for benefits similar to the polyaxial screw assembly12,212, which enables re-use of existing tooling and fewer complicated manufacturing steps. The head component312houses the saddle314and clip316. The saddle314includes upper seat110for receiving the rod18and a bottom surface for receiving the top of the screw head80. Opposite sides of the saddle314have flat surfaces318configured to mate with corresponding flat surfaces320inside the tulip head312. The flats320in the tulip head312may be positioned inside each arm26below the threaded portion34. The mating flat surfaces318,320on the outside of the saddle314and inside head312restrict the saddle314from angling within the tulip312. The clip316may include a loop, ring, split-ring, snap ring, or other suitable retaining ring. In an exemplary embodiment, the clip316is a split retaining clip. The clip316rests in a groove322in the base of the tulip312and is configured to fit around the bottom of the screw head80. The clip component316retains the bone screw14within the assembly310and resists compressive force exerted down on the bone screw14. In this embodiment, the screw head80includes spherical surfaces324in the direction of motion (e.g., aligned with the rod18), and flat opposing surfaces326parallel to the direction of angulation, which restrict angulation in the perpendicular direction. The flat surfaces326of the head80align with corresponding flat surfaces328inside the saddle314. These flat surfaces326,328restrict rotation of the bone screw14about the central axis of the tulip312. Orientation of the flat surfaces326,328in the saddle314perpendicular to the view shown inFIG.14Bresults in the restriction of angulation in the opposite direction. In particular, the flats326,328restrict medial-lateral angulation for uniplanar functionality. The tulip head312pivots on the screw head80in one direction (e.g., medial-lateral angulation). It will be appreciated that the tulip head12is permitted to pivot either along the rod slot30or perpendicular to the rod slot30depending on the configuration of the components. The orientation of the flat surfaces326,328parallel to the rod slot30results in a uniplanar screw able to control coronal and axial corrections. The orientation of these surfaces326,328perpendicular to the rod slot30results in a uniplanar fracture screw able to control sagittal corrections commonly used in correcting traumatic fractures. When the saddle314is in an upward position, the saddle314is able to accept the screw head80and allows the insertion of clip316which retains the screw head. As shown inFIG.14B, when the saddle314is then translated downward within the tulip head162, the screw head80is retained within the tulip assembly. The saddle314compresses against the head80of the screw when threaded locking cap16is threaded downwardly onto the spinal rod18, thereby pushing against the saddle314. The saddle314applies compressive force to the bone screw14and restricts its angulation when the rod18is tightened to the implant310with the locking cap16. In this locked position, the uniplanar screw assembly310is locked in place, thereby restricting motion. The devices and assemblies described herein may allow for improved functionality, strength, and ease of manufacturing for pedicle screw head assemblies. The component features may simplify geometries to reduce profile, increase strength, and/or simplify manufacturing and assembly. Although the invention has been described in detail and with reference to specific embodiments, it will be apparent to one skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. Thus, it is intended that the invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. It is expressly intended, for example, that all components of the various devices disclosed above may be combined or modified in any suitable configuration.

11857223

DESCRIPTION OF THE EMBODIMENTS For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification. It is understood that no limitation to the scope of the invention is thereby intended. It is further understood that the present invention includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the invention as would normally occur to one skilled in the art to which this invention pertains. Referring toFIGS.1-2a modular apparatus10is shown for extending an existing spinal construct that includes an existing spinal rod12(shown in phantom) so as to increase the level of spinal fixation in a patient having previously undergone spinal fusion or other spinal surgery. The modular apparatus10generally comprises a rod connector14, a modular rod extender16and a locking element is. In one arrangement, locking element18is a set screw that has external threads18a. In use, the existing spinal rod12and the modular rod extender16are typically located ipsilaterally in the spine. Spinal rod12is an existing spinal construct in the sense that it has been installed prior to the installation of the modular apparatus10, which means that existing spinal rod12may have been placed in a previous surgical procedure or may be placed during the same surgical procedure as, but prior to, modular apparatus10. As will become more evident, modular apparatus10is an enhancement over the rod connector shown and described in the above referenced, commonly assigned '906 Patent which comprises a lower portion that is attachable to an existing spinal rod and an upper portion with an integral additional spinal rod that is pre-attached polyaxially to the lower portion. As will be described, rod connector14and modular rod extender16are separate components that are attached in a modular fashion, for example during a surgical procedure, to form the modular apparatus10. Turning now also toFIGS.3-4, details of rod connector14are described. Rod connector14comprises an attachment portion20that includes, in one arrangement, a pair of spaced hooks22and24each of which includes a respective projecting rod engagement member22aand24a. Hooks22and24are spaced from each other at a distance defining an opening26that allows the existing rod12to be received therebetween. A threaded opening28is formed into attachment portion20opposite hooks22and24, with threaded opening28being in communication with rod receiving opening26. An elongate post30has a lower threaded portion30aand an upper head30bhaving an outer surface formed as a truncated sphere. Head30bmay have annular ridges30cas seen inFIGS.2and4, or a suitable serrated surface to assist in the securement of post30to modular rod extender16, as will be described. A socket30dmay be included to extend into upper head30b, socket30dbeing in a suitable configuration such as a hexalobe to receive a tool for attaching rod connector14to existing spinal rod12and for securing rod connector14thereto. Threaded portion30ais threadably received in threaded opening28of attachment portion20to form rod connector14. Turning in addition toFIGS.5-11, further details of modular rod extender16are described. Modular rod extender16comprises an extender body32and an extension rod34attached thereto. Extender body32comprises a modular attachment feature36at one end32aand a rod attachment feature38at an opposite end32b. Modular attachment feature36comprises a central bore40formed through a top surface32cand a bottom surface32dof extender body32, a socket collar42, a crown44and a retention insert46. Central bore40extends along an axis41as shown inFIG.6and has internal threads40ain an upper portion adjacent top surface32c. Extension rod34is elongate and serves to provide an additional rod to extend the existing construct from existing spinal rod12to another spinal level where it may be attached to a further pedicle screw or other suitable bone anchor. Extension rod34is attached to extender body32by rod attachment feature38as shown inFIGS.5-6, which may include external threads34athreadably engaging internal threads38aformed into extender body32at end32b. Extension rod34may be welded to extender body32subsequent to threaded engagement thereto to further secure the connection. Alternatively, extender body32and extension rod34may be formed as an integral, one-piece member. As shown inFIGS.5-6, extender body32and extension rod34form an in-line modular rod extender16wherein the longitudinal axis of extension rod34is axially aligned with extender body32and, particularly with central bore40. Referring now toFIGS.4and7-8, further details of central bore40forming a portion of modular attachment feature36are described. The lower portion of central bore40adjacent bottom surface32dis formed to have a lower opening48and a lower interior cavity50, lower interior cavity50communicating with lower opening48and central bore40. Lower opening48has a diameter greater that the maximum diameter of spherical outer surface of post head30bsuch that post30may be bottom loaded through lower opening48. An outwardly downwardly flared chamfer48amay be formed at the bottom of lower opening48. Lower interior cavity50has a first region52, a second region54and a third region56. First region52communicates with lower opening48and preferably has a first partially spherical internal surface52ahaving a first radius of curvature. First region52has a portion that is diametrically wider than the diameter of opening48. Second region54communicates with first region52and preferably has a second partially spherical internal surface54ahaving a second radius of curvature. The second radius of curvature of second internal surface54ais in one arrangement less than the first radius of curvature of first internal surface52a. Second region54has a portion that is diametrically wider than the widest diameter of region52. Third region56communicates with second region54and preferably has a cylindrical internal surface56a. Third region56is substantially as wide as the widest portion of second region54and greater than the diameter defining central bore40. A ledge55extends radially interiorly within extender body32, ledge55having an upper contact surface57and a lower surface defining an interior stop surface58. Third region56terminates interiorly of lower interior cavity50at interior stop surface58that extends transversely relative to cylindrical internal surface56a. Formation of the second region54and third region56allows for expansion of socket collar42, as will be described. Referring again toFIGS.4and7-8, details of socket collar42are described. Collar42comprises a ring60of generally circular configuration having a generally circular central opening62. Ring60includes a top surface60aand a bottom surface60bthat in one arrangement are substantially parallel. Opening62preferably has a partially spherical internal surface64having a radius of curvature, R1. The radius of curvature of internal partially spherical surface64is in one arrangement substantially the same as the radius of curvature of the outer spherical surface30bof post30. Ring60has an outer surface66that preferably includes a partially spherical external surface that has a radius of curvature, R2that is greater than the radius of curvature, R1of internal surface64. The radius of curvature of external partially spherical surface66is in one arrangement substantially the same as the radius of curvature of first partially spherical surface52ain the lower interior cavity50at the lower portion of central bore40. As such, socket collar42cannot pass through the lower portion of central bore40. In a preferred arrangement, ring60is split as defined by a gap68as shown inFIG.7that extends angularly through ring60. Gap68allows a certain amount of radial expansion and contraction of ring60. In the unexpanded condition of socket collar42, opening62has a dimension that is less than the maximum diameter of head30bof post30such that head30bmay not pass therethrough unless socket collar42is expanded. Further details of socket collar42and its function are set forth in commonly assigned U.S. patent application Ser. No. 16/843,160, issued as U.S. Pat. No. 11,219,470, entitled “Modular Tensioned Spinal Screw”, filed by Eugene Avidano on Apr. 8, 2020, the entire contents of the '160 application being incorporated herein by reference. Referring yet again toFIGS.4and7-8, further the details of crown44are described. Crown44is of generally cylindrical configuration having an upper end44aand an opposite lower end44bwith a bore44cextending therethrough. As best seen inFIG.7, crown44includes a pair of lobes70that project outwardly radially oppositely from crown44and provide crown alignment, as will be described. Exteriorly between lobes70crown44includes a generally cylindrical body72having a diameter slightly smaller than the diameter defining central bore40. A lower interior surface74at the lower end44bof crown44is formed to have a partially spherical concave surface having a radius of curvature that in one arrangement is substantially the same as the radius of curvature of the outer spherical surface of past head30b. Referring still further toFIGS.4and7-8, additional details of retention insert46are described. Retention insert46is generally cylindrical having a central opening46aextending therethrough. In one arrangement, retention insert46has internal threads46bin central opening46aand external threads46cextending on an outer surface of retention insert46. Internal threads46bare configured to threadably receive external threads18aof locking element18while external threads46con retention insert46are configured for threadable receipt into internal threads40aof central bore40, as will be described. Turning now toFIGS.9-11, additional details of extender body32are described. As shown particularly inFIGS.10and11, central bore40has a pair of opposing cutouts40bformed into an interior surface40cthat has a diameter defining central bore40. Cutouts40bare configured to receive respective lobes70of crown44in assembly, as will be described. Top surface32cmay be formed to include an opening76that is configured to receive a portion of an insertion instrument that is used to introduce modular rod extender16to the surgical site. In one arrangement, opening76may have an oval shape so as to provide suitable alignment between the insertion instrument and modular rod extender16. Opening76may be formed to extend partially into extender body32through top surface32c(seeFIG.6). Alternatively, opening76may be formed to extend fully through extender body32. The components of rod connector14and modular rod extender16may comprise any suitable biocompatible material, including but not limited to titanium, cobalt chrome and PEEK. Having described details of the components of modular apparatus10, the assembly of the components to form modular rod extender16is now described with particular reference toFIGS.4and6-8. Socket collar42, crown44and retention insert46are sequentially introduced into central bore40of extender body32in a top-loading process. Socket collar42, introduced initially, is rotated 90° so that top surface60aand bottom surface60bof socket collar42respectively face internal threads40awithin central bore40. In this manner socket collar42, with slight contraction if necessary, is capable of passing through central bore40until socket collar42reaches the wider lower interior cavity50adjacent bottom surface32dof extender body32. Socket collar42is then rotated 90° within lower interior cavity50to the position shown inFIG.4wherein socket collar42rests floatingly on first partially spherical internal surface52aof lower interior cavity region52. Crown44is then introduced into inner central bore40in a top-loading process whereby lobes70are oriented in alignment with cutouts40b, as shown inFIGS.10and11. In this orientation, crown44is in a fixed alignment with extender body32and will be prevented from rotation and thereby remain in a fixed position during modular attachment of rod extender16to rod connector14, as will be described. In certain instances, crown44may be formed of a softer material such as commercially pure titanium (CP Ti). This would allow crown44to lock against head30bof rod connector post30during use, as will be described. Retention insert46is then introduced into central bore40by threading external threads46cinto internal threads40aof central bore40. Upon reaching the proper position within central bore40when retention insert46bottoms out on upper contact surface57of ledge55, insert46is secured therein by a suitable process, such as by welding. As so secured, retention insert46is fixed in position relative to central bore40and covers lobes70of crown44, effectively retaining socket collar42and crown44within central bore40. With retention insert46secured in such a fixed position and with socket collar42being prevented from passing out through the bottom of central bore40, both socket collar42and crown44may move up and down to a degree within central bore40until post30is modularly received. It should be appreciated that retention insert46may also be formed, for example, as a bushing that is welded in place, thereby potentially eliminating the need for external threads46cand internal threads40awithin central bore40. In use for spinal surgery, a kit may be provided comprising a plurality of rod connectors14and a plurality of modular rod extenders16. The rod connectors14may be modular and configured to each have a different rod receiving opening26to accommodate existing spinal rods12of different diameter. The modular rod extenders16may have extension rods34of different lengths and different diameters to accommodate different surgical procedures or patient anatomies. However, the heads30bof each rod connector post30are commonly formed to have a spherical surface having the same size and configuration such that any selected modular rod extender16may be attached to a selected rod connector14. It should therefore be appreciated that the subject modular apparatus10provides flexibility and options for the surgeon in selecting appropriate spinal fixation implants depending upon surgical circumstances and anatomies in a cost-effective manner. After selection of a suitable rod connector14and a suitable modular rod extender16, the chosen rod connector14is placed on the existing spinal rod12by introducing the existing spinal rod12into rod receiving opening26. Rod connector14is rotated such that hooks22and24straddle existing spinal rod12. Such placement and rotation of rod connector14may be achieved by a suitable instrument. Rod connector14may be slid axially along existing spinal rod12to a position determined to be appropriate by the surgeon. Post30is then tightened against existing spinal rod12by a tool engaged with socket30dto cause rod engagement members22aand24ato engage and securely lock the chosen rod connector14onto the existing spinal rod12. A chosen modular rod extender16may then be pushed by an appropriate instrument on to the spherical outer surface of head30bof post30to form the assembled modular apparatus as shown inFIG.1, prior to placement of locking element18. In some circumstances, locking element18may be pre-attached to modular rod extender16before modular attachment to rod connector14. Upon downward movement of modular rod extender16onto head30b, head30bmoves socket42axially upwardly into the wider regions54and56of lower interior cavity50of central bore40since head30bcannot pass through socket collar opening62in the relaxed unexpanded condition. Upon further relative movement of head30bupwardly socket collar top surface60awill ultimately contact interior stop surface58within lower interior cavity50. Continued movement of modular rod extender16downwardly will then push head30into and through socket collar opening62to expand the socket collar20radially via the gap68. Once the spherical head30bof post passes through collar opening62an audible click may be heard together with a tactile feel as socket collar42returns to its non-stressed radius. At this point, socket collar42will be disposed below the maximum diameter of post head30b, as shown inFIG.4. In such assembled but unlocked configuration, rod extender16may be moved polyaxially and rotationally on post head30brelative to rod connector14. It should also be appreciated that while a chosen rod connector14may be initially separately placed on and secured to an existing spinal rod12as described, where appropriate access to socket30dof post30through central bore40is provided, the chosen rod connector14and the chosen modular rod extender16may be pre-attached and jointly placed on existing spinal rod12. To tighten modular rod extender16to rod connector14, locking element18may then be threaded into internal threads46bof retention insert46. Locking element18includes an interior socket18b(seeFIGS.1and2) formed to have a hexalobe shape or other suitable configuration for receipt of a driver instrument (not shown) for threading locking element18into internal threads46bof retention insert46. Upon tightening, locking element18will engage upper end44aof crown44. Continued tightening will push crown44further downward within central bore40causing lower concave surface74of crown44to forcibly engage head30bof post30. This in turn moves post head30bfurther downward as extender body32moves relatively upward. Such relative movement causes the bottom of post head30bto forcibly engage socket collar42and wedge socket collar42rigidly against first partially spherical internal surface52aat the lower end of central bore40. Upon complete tightening of locking element18, modular rod extender16and rod connector14are securely coupled, thereby preventing relative movement therebetween. Annular ridges30con post head30benhance the security of the connection between post head30band socket collar42. Having described a particular arrangement of modular apparatus10wherein modular rod extender16has an extension rod34in-line with modular attachment feature36, two alternative embodiments are now described. The first alternative arrangement is shown and described with reference toFIGS.12and13. A modular rod extender116comprises elongate extension rod34attached to a curved extender body132by rod attachment feature38. Curved extender body132is substantially the same in all respects as modular extender body32, including modular attachment feature36, except that it is curved in a plane transverse to the direction of central bore40. Such curvature results in a lateral offset orientation of the longitudinal axis of extension rod34relative to central bore40. The curvature of curved extender body132may be formed in a manner to allow extension rod34to be positioned closer to the midline axis of the patient's spine or in an opposite manner to allow extension rod34to be positioned farther away from the patient's midline axis. Such a curved extender body132is configured to provide a lower profile extension of an existing spinal construct. Turning now toFIGS.14and15the second alternative arrangement is shown and described. In this embodiment modular rod extender116, as described with reference toFIGS.12and13, is modularly attachable to a lateral rod connector114. Lateral rod connector114has a side opening126for lateral receipt of an existing spinal rod12. Lateral rod connector114may be suitably attached to existing spinal rod12by a fastening element (not shown) threadably engaging threaded opening118. Lateral rod connector114includes an elongate post130similar to post30of rod connector14. Post130has an upper head130bhaving an outer surface formed as a truncated sphere, which may include annular ridges130cor other suitable high friction surface. Post head130bis received in modular attachment feature36of modular rod extender116in the same manner as post30of rod connector14is received in modular rod extender16, as described above. Initial attachment is unlocked and allows polyaxial and rotational movement of modular rod extender116on post head130b, relative to lateral rod connector114. Modular rod extender116may be subsequently locked in a desired orientation to lateral connector114by advancing locking element18into threads40acentral bore40. This arrangement is configured to allow not only for a lower profile extension of existing spinal rod12, but also a substantial co-axial orientation of extension rod34relative to an existing spinal rod12, while potentially passing around existing spinal constructs. While the invention has been illustrated and described in detail in the drawings and foregoing description, the same should be considered as illustrative and not restrictive in character. It is understood that only the preferred embodiments have been presented and that all changes, modifications, and further applications that come within the spirit of the invention are desired to be protected.

11857224

DETAILED DESCRIPTION This disclosure relates to a bone plate for vertebral (e.g., cervical and/or lumbar) fusion. Cervical bone plates are generally placed in an anterior position on the cervical vertebra and held in place with bone screws. Lumbar bone plates are generally placed in a lateral position on the lumbar vertebra and held in place with bone screws. A locking mechanism is used to keep the bone screws from backing out after implant. In some embodiments, the locking mechanism is in the form of a screw that is quickly and easily installed by a surgeon. The locking screw can be positioned adjacent to the one or more screw(s) that attach the cervical bone plate to each vertebral bone. In some embodiments, the locking mechanism is in the form of a screw that is quickly and easily installed by a surgeon. The head of the locking screw is of sufficient size that it lays over or partially covers the bone screw, to prevent the bone screw from backing out. The locking screw is removable if necessary. In some embodiments, the locking mechanism is in the form of a screw that is quickly and easily installed by a surgeon and is also easily removed in the event that that is easily insertable into an opening above the bone screw to prevent the bone screw from backing out. The locking screw is removable if necessary. In some embodiments, the locking screw comprises a shaft and threads, and has a partially open shaft which allows for the threads and shaft to have a variable diameter where the threads and shaft can be forced inward to assume a smaller outside diameter. A radial inward force applied to the screw can cause the screw to assume a smaller diameter. When no force is applied, the screw can assume its standard diameter. In some embodiments, the threads on the locking screw have a slight upward slant. This slant can allow for less force being needed to force the screw into the bone plate shaft. It will also help prevent the screw from being pushed out of the opening in the bone plate. In some embodiments, the locking screw has a thread direction that is opposite of the bone screw. For instance, a bone screw may have right handed threads, meaning that rotating the screw to the right (e.g., clockwise) causes it to advance and rotation to the left (e.g., counterclockwise) causes the screw to retract. In such cases, if the bone screw has right handed threads, the locking screw can have left handed threads. In the event that the bone screw begins to come out of the bone, the left-handed rotation will not cause the locking screw to back out. In some embodiments, the bone screw locking mechanism includes a snap ring. Such embodiments may include a tool to open the snap ring. In some embodiments, the bone screw locking mechanism is a resilient band, connected to the bone plate, that is placed over the bone screw. Before describing various embodiments of the present disclosure in detail, it is to be understood that this disclosure is not limited to the parameters of the particularly exemplified implants, methods, systems and/or products, which may, of course, vary. Thus, while certain embodiments of the present disclosure will be described in detail, with reference to specific configurations, parameters, features (e.g., components, members, elements, parts, and/or portions), etc., the descriptions are illustrative and are not to be construed as limiting the scope of the claimed disclosure. In addition, the terminology used herein is for the purpose of describing the embodiments and is not necessarily intended to limit the scope of the claimed disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure pertains. Various aspects of the present disclosure, including implants, systems, processes, and/or products may be illustrated with reference to one or more embodiments or implementations, which are exemplary in nature. As used herein, the terms “embodiment” and “implementation” mean “serving as an example, instance, or illustration,” and should not necessarily be construed as preferred or advantageous over other aspects disclosed herein. In addition, reference to an “implementation” of the present disclosure or disclosure includes a specific reference to one or more embodiments thereof, and vice versa, and is intended to provide illustrative examples without limiting the scope of the disclosure, which is indicated by the appended claims rather than by the following description. As used throughout this application the words “can” and “may” are used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Additionally, the terms “including,” “having,” “involving,” “containing,” “characterized by,” as well as variants thereof (e.g., “includes,” “has,” and “involves,” “contains,” etc.), and similar terms as used herein, including the claims, shall be inclusive and/or open-ended, shall have the same meaning as the word “comprising” and variants thereof (e.g., “comprise” and “comprises”), and do not exclude additional, un-recited elements or method steps, illustratively. It will be noted that, as used in this specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a “locking screw” includes one, two, or more locking screws. As used herein, directional terms, such as “top,” “bottom,” “left,” “right,” “up,” “down,” “upper,” “lower,” “proximal,” “distal,” “vertical,” “horizontal” and the like are used herein solely to indicate relative directions and are not otherwise intended to limit the scope of the disclosure and/or claimed disclosure. Various aspects of the present disclosure can be illustrated by describing components that are bound, coupled, attached, connected, and/or joined together. As used herein, the terms “bound,” “coupled”, “attached”, “connected,” and/or “joined” are used to indicate either a direct association between two components or, where appropriate, an indirect association with one another through intervening or intermediate components. In contrast, when a component is referred to as being “directly bound,” “directly coupled”, “directly attached”, “directly connected,” and/or “directly joined” to another component, no intervening elements are present or contemplated. Furthermore, binding, coupling, attaching, connecting, and/or joining can comprise mechanical and/or chemical association. To facilitate understanding, like reference numerals (i.e., like numbering of components and/or elements) have been used, where possible, to designate like elements common to the figures. Specifically, in the exemplary embodiments illustrated in the figures, like structures, or structures with like functions, will be provided with similar reference designations, where possible. Specific language will be used herein to describe the exemplary embodiments. Nevertheless, it will be understood that no limitation of the scope of the disclosure is thereby intended. Rather, it is to be understood that the language used to describe the exemplary embodiments is illustrative only and is not to be construed as limiting the scope of the disclosure (unless such language is expressly described herein as essential). Furthermore, multiple instances of an element and or sub-elements of a parent element may each include separate letters appended to the element number. An element label with an appended letter can be used to designate an alternative design, structure, function, implementation, and/or embodiment of an element or feature without an appended letter. Likewise, an element label with an appended letter can be used to indicate a sub-element of a parent element. However, element labels including an appended letter are not meant to be limited to the specific and/or particular embodiment(s) in which they are illustrated. In other words, reference to a specific feature in relation to one embodiment should not be construed as being limited to applications only within said embodiment. Furthermore, multiple instances of the same element may each include separate letters appended to the element number. For example, two instances of a particular element “20” may be labeled as “20a” and “20b”. In that case, the element label may be used without an appended letter (e.g., “20”) to generally refer to every instance of the element; while the element label will include an appended letter (e.g., “20a”) to refer to a specific instance of the element. It will also be appreciated that where multiple possibilities of values or a range a values (e.g., less than, greater than, at least, or up to a certain value, or between two recited values) is disclosed or recited, any specific value or range of values falling within the disclosed range of values is likewise disclosed and contemplated herein. The human spine is naturally curved. Normal lordosis is the two forward curves seen in the neck (cervical spine) and low back (lumbar spine). Normal kyphosis is the two backward curves seen in the chest (thoracic spine) and hip areas (sacral spine). Each of the naturally occurring and normal soft curves serves to distribute mechanical stress incurred as the body is at rest and during movement. The devices disclosed herein are described in terms of treatment for the cervical spine and/or lumbar spine. In general, cervical spinal fusion is an anterior intervention, but in some instances may be lateral or posterior. In general, lumbar spinal fusion is a lateral intervention, but in some instances may be lateral or posterior. Compared to the thoracic and lumbar regions, the cervical vertebra are smaller and closer together. Compared to the cervical regions, the thoracic and lumbar vertebra are larger and farther apart. FIG.1Ais a perspective view of a bone plate in accordance with one or more embodiments of the present disclosure.FIG.1Bis a perspective view of a bone plate in accordance with one or more embodiments of the present disclosure. Depicted inFIGS.1A and1Bare two embodiments of bone plates incorporating features of the present disclosure. InFIG.1A, bone plate100is designed to be used for stabilizing two adjacent vertebrae of a spine as part of a procedure for fusing together the adjacent vertebrae. Bone plate100can also be used for stabilizing a series of consecutive vertebrae for manipulation of the spine to correct spinal deformities such as scoliosis. It is appreciated that bone plate100and/or discrete elements thereof can also be used in other procedures for anchoring, manipulating, and/or stabilizing various bones. Bone plate100comprises a main body102having a top surface104and an opposing bottom surface106that extend longitudinally from a proximal end108to a spaced apart distal end110. Top and bottom surfaces104and106also extend laterally from a first side112to a spaced apart second side114. Main body102can be curved in one or more directions or can be substantially planar. A plurality of apertures116are formed in main body102that extend completely through main body102between top surface104and bottom surface106. Each aperture116is designed so that the shaft122of a bone screw120can be inserted therethrough while the head124of the bone screw120is prevented from doing so. In some embodiments, aperture is countersunk so that head124of screw120is either flush with surface104or slightly below. Bone screw120is threaded into a vertebra while head124biases against bone plate100so as to rigidly attach the vertebra to bone plate100. Other apertures can also be included in main body102to aid the physician in implanting the bone plate within the body. For example, as shown inFIG.1A, a viewing aperture130that passes completely through main body102is positioned generally centrally on the main body102so as to allow the physician to view the underlying spine when installing the bone plate100. The number of viewing apertures130can vary. For example, in some embodiments, a single viewing aperture130is positioned on main body102. In other embodiments, a plurality of viewing apertures130are incorporated. In other embodiments, viewing apertures130are omitted altogether. The bone plate200, shown inFIG.1B, can be attached to three vertebrae. It is noted, however, that attachment to four, five, six, or more vertebra are within the scope of the disclosure. In some embodiments, locking screw apertures are included in the bone plates100and200. Apertures118can be threaded so as to receive a locking screw.FIG.1Dis a side view of a locking screw150in accordance with one or more embodiments of the present disclosure. Locking screw150includes screw head152and screw body154. Screw body154includes slot156that extends the length of screw body154and into the interior of body154so as to give screw150a non-continuous cross section. FIG.1Eis a cross-sectional view of a locking screw in accordance with one or more embodiments of the present disclosure.FIG.1Fis a cross-sectional view of a locking screw in accordance with one or more embodiments of the present disclosure. As shown inFIG.1E, slot156can extend to the outer surface of screw body154in three places. As shown inFIG.1F, slot156can extend to the outer surface of screw body154in four places. The screw body154can have a variable diameter, where a radial inward pressure on the screw body154can cause the sections of body154to move radially inward, causing the body154to have a smaller effective diameter. FIG.1Gis a cross-sectional view of a locking screw subject to radial pressure in accordance with one or more embodiments of the present disclosure.FIG.1His a cross-sectional view of a locking screw subject to radial pressure in accordance with one or more embodiments of the present disclosure. When the radial pressure is released, the slots156in screw body154can reform and the cross section will again look like that shown inFIGS.1E and1F. WhileFIG.1Eshows three openings on the circumference andFIG.1Fshows four openings on the circumference, any number of slots (and thus slot openings) can be used in accordance with embodiments herein. In some embodiments, after a surgeon has attached bone plate100or200to a vertebra, locking screw150can be forced into aperture118. As the screw has a non-continuous cross section, the diameter will get smaller due to the force of screw150being forced into aperture118. Once in place, the sections of screw body154will expand to the original diameter and the threads of screw150will mate with the threads of aperture118securing screw150in the aperture. The surgeon can tighten the screw by rotating head152. Screw150can be unthreaded and removed from aperture118. Aperture118can be placed adjacent each aperture116or pairs of apertures116and can be sized such that head152will partially cover head124of bone screw120. In some embodiments, aperture118can be counter sunk so that the top of screw head152is at or below surface104even when it is over bone screw head124. In some embodiments, apertures116are threaded so as to receive a locking screw150that will be placed on top of bone screw120. In such embodiments, after the surgeon has inserted bone screws120into plate100or200, locking crews150can be inserted on top of bone screw120to keep the bone screw from backing out. In some embodiments, the locking screw can have a thread direction that is opposite the thread direction of the bone screw. For example, if the bone screw if right threaded (to advance it is turned to the right) the locking screw can be left threaded so that the left rotation that may result from the bone screw backing out will not cause the locking screw to back out. In some embodiments, plates100and200may not include locking screw apertures118. FIG.1Iis a cross-sectional view of a locking screw in accordance with one or more embodiments of the present disclosure. As shown inFIG.1I, locking screw160can include a head162, screw body164, slot166, and threads168. As shown, threads168can be pointed toward the screw head162. The angle of the threads168can be from 1° to 45° away from a line perpendicular to the longitudinal axis of the screw160. The angle of the threads168can be from 5° to 25° away from a line perpendicular to the longitudinal axis of the screw160. The angle of the threads168can be from 10° to 20° away from a line perpendicular to the longitudinal axis of the screw160. The upward angled threads can result in less pressure being needed to force the locking screws into aperture116or118and can reduce the chance of the screw backing out of the aperture in the event that the screw does not return to the full diameter after the radial force is released. FIG.2Ais a top view of a snap ring in accordance with one or more embodiments of the present disclosure. Snap ring200has a slot204that allows the ring to open and attachment point202where the snap ring is attached to a bone plate.FIG.2Bis a side view of a snap ring in accordance with one or more embodiments of the present disclosure.FIG.2Cis a side view of a snap ring in accordance with one or more embodiments of the present disclosure. As seen in2B and2C, the snap ring can be described as a non-continuous ring having a vertical and/or angled slot204. FIG.2Dis a top view of a bone plate with a snap ring in accordance with one or more embodiments of the present disclosure.FIG.2Dshows bone plate201with snap rings200positioned within bone screw apertures216.FIG.2Eis a detailed top view of a portion of a bone plate with a snap ring in accordance with one or more embodiments of the present disclosure. As shown in more detail inFIG.2E, snap ring200can be positioned within aperture216and attached to bone plate201at point202. Aperture216can have a diameter greater than or equal to the head of the bone screw120(previously described in connection withFIG.1) plus the thickness of snap ring200. When the surgeon installs bone screw120and the bottom of head124pushes on snap ring200, the downward pressure of screw head124on the snap ring will cause slot204to widen. Once head124is beneath snap ring200, the ring may ‘snap’ shut or close and hold screw120in place. If screw120is to be removed, the surgeon can pry slot204open with a flat instrument, causing the diameter of the ring to get larger, at which time the screw head can fit through the snap ring and the screw can be removed. In some embodiments, the bottom of head124can be used to help push ring200open. FIG.2Fis a top view of a resilient band bone screw locking mechanism in accordance with one or more embodiments of the present disclosure. As shown inFIG.2F, a resilient band or wire240can be positioned in aperture216of plate201. Resilient band or wire240can be attached at both ends to bone plate201with the middle section extending into the aperture216. To install a bone screw, the surgeon can bend mechanism240up so that screw120can be inserted into the bone through aperture216. Once the screw is installed, the surgeon can release mechanism240and allow it to return to its original position. Once positioned on top of screw head124, the resilient band or wire240can prevent the screw from backing out. In the event that the screw needs to be removed, the surgeon can again bend the resilient band or wire240up and out of the way so that screw120can be removed. Plates100,200and201and screw120,150, and160can be cast, molded, milled or otherwise formed from a biocompatible material such as a polyetheretherketone (PEEK) polymer that can be reinforced with a fiber, such as carbon fiber, and/or other additives. In alternative embodiments, the plates and screws of the present disclosure can be formed from medical grade biocompatible metals (such as titanium), alloys, polymers, ceramics, or other materials that have adequate strength. The heads of the locking and bone screws of the disclosure (124,152,162) can be formed with a recess to accept a tool that a surgeon may use to turn the screw. This opening can be a slot, a cross, or an opening with three, four, five, six, seven or more sides. In some embodiments, the bottom side of screw heads124,152,162can be tapered or sloped. In some embodiments, the taper of slope can match a counter sink in the screw apertures. In some embodiments, all of the screw apertures116and118are counter sunk such that when the bone and locking screws120,150,160are inserted, the top of the screw heads are flush with surface104. When the bone plates described herein are used in an anterior cervical discectomy and fusion technique, an incision can be made in the front of the neck which allows the surgeon to remove the damaged and protruding disc and associated bone spurs in order to relieve any pressure on the spinal cord and nerve roots. When the bone plates described herein are used in a lateral lumbar discectomy and fusion technique, an incision can be made in the abdomen which allows the surgeon to remove the damaged and protruding disc and associated bone spurs in order to relieve any pressure on the spinal cord and nerve roots. After the disc is removed, the gap that has been created between the two bones is then typically filled with a piece of bone graft (obtained from a cadaver or from the patient's pelvis) or with a synthetic material. In some instances, the bone graft material is carried in a titanium or medical grade plastic cage device. Once the pressure on the nerves has been relieved, the goal of the procedure is to cause the two bones to grow together (called a fusion). While procedures herein have been described with respect to particular example placements (e.g., lateral, anterior, posterior), it is noted that other placements other than those specifically described may be used in accordance with embodiments herein. For cervical applications, the term means that at least one cervical vertebra is involved. For lumbar applications, the term means that at least one lumbar or thoracic vertebra is involved. The present disclosure may be embodied in other specific forms without departing from its spirit or essential characteristics. For example, the placement, orientation and number of bone screws and locking screws can be modified as needed. For example, in one embodiment, only two bone screws may be used and thus only one locking screw may be required. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the disclosure is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

11857225

DETAILED DESCRIPTION Certain exemplary embodiments will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the devices, systems, and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. The devices, systems, and methods specifically described herein and illustrated in the accompanying drawings are non-limiting embodiments. The features illustrated or described in connection with one embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present disclosure. Additionally, to the extent that linear, circular, or other dimensions are used in the description of the disclosed devices and methods, such dimensions are not intended to limit the types of shapes that can be used in conjunction with such devices and methods. Equivalents to such dimensions can be determined for different geometric shapes, etc. Further, like-numbered components of the embodiments can generally have similar features. Still further, sizes and shapes of the devices, and the components thereof, can depend at least on the anatomy of the subject in which the devices will be used, the size and shape of objects with which the devices will be used, and the methods and procedures in which the devices will be used. The present disclosure generally relates to multiple set screw insertion instruments and methods of use that address challenges of prior approaches. The multiple set screw insertion instrument disclosed herein can reduce the number of passes of instruments between a surgeon and assistant while maintaining the ability to deliver set screws to affix spine surgery instrumentation. In one embodiment, the multiple set screw insertion instrument can include an inner driver shaft having a plurality of set screws stacked thereon, and an outer driver sleeve having a ratcheting portion for stepwise advancement of set screws along the inner driver shaft for insertion into bone anchors and other spinal instrumentation. The inner driver shaft and the outer sleeve can be received within a handle having a button for actuating the instrument. Actuation of the instrument can result in relative movement between the inner driver shaft and the outer sleeve to sequentially eject set screws from the instrument into a bone anchor receiver head or other spinal instrumentation. FIGS.1-2Billustrate one embodiment of a multiple set screw insertion instrument or inserter instrument100. The multiple set screw insertion instrument100can be used to deliver set screws to spinal instrumentation during procedures, e.g., spinal surgery. The instrument100can include an inner driver shaft102, an outer sleeve104, and a handle106configured to receive the inner driver shaft102and the outer sleeve104therein. The inner driver shaft102can include a drive feature108for receiving a plurality of set screws110thereon. In some embodiments, the instrument100can include a central longitudinal axis A1extending therethrough such that the axis A1passes through one or more of the inner driver shaft102, the outer sleeve104, and/or the handle106. In use, the inner driver shaft102can be received inside the outer sleeve104, with the outer sleeve being configured to translate relative to the inner driver shaft102. Translation of the outer sleeve104can sequentially advance a set screw110of the plurality of set screws110to a distal tip112located on the drive feature108of the inner driver shaft108after ejection of a previous set screw from the instrument, e.g., due to insertion of the previous set screw into spinal implementation. FIGS.2A-2Bin particular illustrate assembly of the multiple set screw insertion instrument100. The inner driver shaft102can include a generally tubular body114having a proximal end102pand a distal end102dwith the central longitudinal axis A1extending therebetween. The tubular body114can be solid, though in some embodiments, the body can be hollow such that an opening extends therethrough. The proximal end102pof the inner driver shaft102can include a mating feature116, e.g., a threaded male member, as shown inFIG.2B, for coupling with a corresponding threaded bore120in the handle106, as described in greater detail below with regard toFIG.4. In some embodiments, the mating feature116can be keyed to be received within the bore in a specific orientation such that the inner driver shaft102couples to the handle106in a specific orientation. The drive feature108at the distal end102dof the inner drive shaft102can be shaped to correspond to an inner opening in the plurality of set screws110. As shown, the drive feature108can be a male Torx®-shaped protrusion extending along a distal portion of the shaft102such that a plurality of set screws110can be stacked on the drive feature108. The plurality of set screws110can include a recess shaped to correspond to the drive feature108to allow the set screws to be secured to the drive feature and rotated therewith while also allowing for proximal translation of the set screws over the drive feature108. In some embodiments, the drive feature108can include a retention feature118, as shown inFIG.3, to prevent unintended separation of the set screws110from the drive feature108. Further details of the retention feature are discussed in greater detail below. The overall profile of the inserter instrument100can be similar to an elongate set screw driver. The outer sleeve104can include a generally tubular body122having proximal and distal ends104p,104ddefining a channel124therebetween. The channel124can extend in a common axis of the central longitudinal axis A1of the inner driver shaft102such that the central longitudinal axis A1extends from the proximal end104pto the distal end104dof the outer shaft104. As shown, the channel124can be configured to receive at least a portion of the inner driver shaft104therethrough. For example, the body122of the outer sleeve104can define an inner diameter ID that is substantially the same size or larger than an outer diameter OD of the inner driver shaft102to receive the inner driver shaft102therethrough. In some embodiments, the outer sleeve104can include a non-uniform outer diameter OD1. For example, the outer diameter OD1of the tubular body122of the outer sleeve104can be larger in some locations than at others. In some embodiments, the outer diameter OD1can taper along a length thereof. In some embodiments, the outer sleeve104can taper from the proximal end104pof towards the distal end104dsuch that the proximal end104pengages one or more features within the handle106to selectively permit or prevent translation of the outer sleeve104relative to the handle and/or the inner driver shaft102. As shown, the outer sleeve104can include a proximal head126thereon having a larger outer diameter OD1than a portion of the sleeve extending distally from the proximal head. The proximal head126can function as a retention mechanism that prevents inadvertent or undesired separation of the sleeve104from the handle106. For example, the proximal head126can interface with the latch or button178to provide a stop against complete removal of the sleeve104from the handle106. The stop can prevent axial translation of the outer shaft104with respect to the other components of the inserter instrument100. While a proximal head126is shown, the stop can include a ribbed surface, a protrusion, a catch, or another component configured to retain the outer sleeve104within the handle106. The outer sleeve104can include a ratchet portion128formed along the tubular body122. As shown, the ratchet portion128can extend along an intermediate section of the outer sleeve104, though in some embodiments, the ratchet portion128can extend along any length of the sleeve. The ratchet portion128can include a series of ratchet teeth, ribs, or protrusions130that are formed along the outer surface of the outer sleeve104. The ratchet portion128can engage with one or more components of the instrument100, such as the pawl178discussed below, for step-wise advancement of the outer shaft104with respect to other components, as discussed in greater detail below. The ratchet portion128can extend around a circumference of the tubular body122to allow the outer sleeve104to be inserted into the handle106in any rotational orientation. In use, the ratchet portion128can allow the outer sleeve104to provide a hard stop behind a set screw, which can aid a user in starting to thread the set screw into the implant and prevent proximal movement of the set screw or outer sleeve if a user exerts axial pushing forces on the device during insertion. In addition, the ratchet portion128can facilitate the advancement of a next set screw toward a distal end of the driver shaft102in connection with insertion of a prior set screw into a spinal fixation construct, such as a bone screw receiver member. The handle106can include a tubular body132having a central lumen134formed therein. The central lumen134can extend from a distal end106dof the handle106to the proximal end106palong the central longitudinal axis A1of the instrument100to receive one or more of the inner driver shaft102and/or the outer sleeve104therethrough. The central lumen can include an inner diameter ID2that can be substantially the same as or larger than an outer diameter OD1of the outer sleeve104to allow the outer sleeve to be disposed within the central lumen134. The central lumen134can include a receiving portion136at the proximal end106pof the handle106. The receiving portion136can extend within the central lumen134to receive the proximal end102pof the inner driver shaft102therein. As shown in greater detail inFIG.4, the receiving portion136can include a bore138having a reduced diameter portion that lies along the central longitudinal axis A1with the central lumen134. In some embodiments, the receiving portion136, or a section of thereof, can be threaded. For example, as discussed above, the receiving portion136can include threads120thereon to allow threading of the inner driver shaft102thereto. During assembly, the proximal end102pof the inner driver shaft102can be inserted into the receiving portion136with the mating feature116threaded into the threads120to couple the inner driver shaft102to the handle106. The receiving portion136can include a lumen140formed therein. For example, the threads120can extend through the receiving portion136and terminate at, or proximate to, the lumen140. The lumen140can receive one or more coupling features of the instrument100therein, as described in greater detail below. The handle106can include a recess142formed at a proximal end106pthereof. For example, as shown, the receiving portion136can terminate distal to the proximal end106pof the handle106to define the recess142therebetween. The recess142can receive one or more components that are configured to actuate the instrument. For example, as shown, a button150can be disposed within the handle106to control advancement of the outer sleeve104to urge the set screws110distally. The handle106can be made from a variety of materials, including any of a variety of plastics, ceramics, or metals, among others. In some embodiments, the handle106can include over-moldings of multiple materials, such as a silicone over-molding formed on another underlying material. The handle106can include a series of openings148at the distal end106dthereof to allow for components of the instrument100to facilitate operation thereof. The series of openings148can extend transversely into the central lumen134to be in communication with the outer sleeve104disposed therein. The series of openings148are discussed in greater detail with respect toFIGS.11and12below. FIG.5illustrates a plurality of set screws110that can used with the multiple set screw insertion instrument100of the present disclosure. As shown, each set screw in the plurality of set screws100can include a female drive feature or through-bore144cut completely therethrough. The set screws110can be stacked on top of one another such that an axis A passing therethrough aligns with the central longitudinal axis A1. The female drive feature144can be configured to receive the male drive feature108of the inner driver shaft102therethrough to dispose the stack of set screws110along the inner driver shaft. For example, the through-bore144can include a geometry complementary to the drive feature108to allow the set screw110to stack onto the inserter shaft102and be rotationally driven by the inserter shaft102when the inserter instrument100is rotated. The through-bore144can be sized to allow for axial translation of each of the set screws110along the drive feature108when the outer sleeve104is advanced relative to the inner driver shaft102. Moreover, each set screw can have an outer diameter OD2and the profile of the outer sleeve104can, in some embodiments, be no larger than the outer diameter OD2of the set screws100. FIGS.6-8illustrate the inserter instrument in greater detail. As shown, the inserter instrument100, when placed in an initial position, includes the inner driver shaft102disposed within the channel124of the outer sleeve104, with both components received within the central lumen134of the handle106. Specifically, as noted above, the mating feature116of the inner driver shaft102can be threaded into the threads120within the receiving portion136, while the proximal end104pof the outer sleeve104can abut the receiving portion136. The plurality of set screws110can be disposed on the drive feature108of the inner driver shaft102distal to the outer sleeve104. FIG.7illustrates a relationship between the stack of set screws110and the inner driver shaft102in greater detail. As noted above, the inner driver shaft102can include a retention feature118, e.g., a spring clip or a circlip, which engages a distal tip112of the drive feature108. As shown inFIG.7, the spring clip118disposed at the distal end of the drive feature108can provide an interference fit between the spring clip and set screw110, thereby limiting unwanted distal translation between the set screws and the drive feature. FIG.8illustrates the interaction of the inner driver shaft102, the outer sleeve104, and the handle106of the inserter instrument100while in the initial position described above. The outer shaft104is received within the central lumen134while the proximal head126abuts the receiving portion136. The bore140can receive a biasing element152, such as a coil spring, that is configured to compress and extend in an axial direction when engaged with one or more components of the instrument100. For example, as shown, the biasing element152can be disposed between the receiving portion136and the button150. The biasing element152can bias the button150proximally such that the button150at least partially extends out of the recess142. FIG.9illustrates the button150in greater detail. As shown, the button150includes a proximal head154and a distal body156extending therefrom. The proximal head154can include an outer diameter (not shown) that is substantially the same or smaller than a diameter of the recess142to allow the head to be disposed within the recess142. The head154can include a distal-facing surface158for engaging a portion of the biasing element152to compress the biasing element when the button150is actuated. In some embodiments, the proximal head154can include a bore160formed therein. The distal body156can include a sidewall162that extends from the proximal head154and runs along an interior portion of the inserter instrument handle106. For example, the handle106can include a lumen164formed therein to allow the distal body156to pass therethrough. The lumen164can, in some embodiments, be separate from the central lumen134. As shown inFIG.8, the lumen164can terminate within an interior of the handle106, e.g., distal to the receiving portion136. In some embodiments, however, the second lumen164can extend through a distal end of the handle106. The distal body156can include one or more access points in the sidewall162thereof. The access points can align with one or more of the openings148in the handle106to facilitate advancement or indexing of the outer sleeve104relative to the handle. For example, the distal body156can include a cutout166formed therein that forms a pair of flanges168,170. The cutout166can align with one or more of the series of openings148in the handle106, as noted above, to allow another component to extend through the handle106and the distal body156simultaneously and engage the outer sleeve104, as discussed further below. As shown, one or more transverse openings172,174can be formed in each of the flanges168,170to facilitate coupling between components disposed within the cutout166. Access points can be formed in an outer surface of the sidewall162. For example, the illustrated top surface of the sidewall162inFIG.9can include a recess176for receiving a biasing element177, such as a coil spring or other biasing element. The biasing element177can, for example, bias another component disposed in the cutout166such that a portion thereof extends into the central lumen134to engage the outer shaft104, as described in more detail below. One embodiment of such a component can be a pawl, latch, or button178(seeFIG.8) that extends into the central lumen134to engage the outer shaft104. For example, the feature178can extend from a distal end178dto a proximal end178p, with the distal end178dhaving an engagement surface180thereon. The engagement surface180can extend radially inward from the cutout166of the button150and the opening148of the handle106to engage the ratchet portion128of the outer sleeve104. The pawl178can be coupled to the button150by a pin182received in the openings172,174of the flanges168,170. The pin182can allow the pawl178to pivot about an axis of the pin182. The proximal end178pof the pawl178can include a recess to receive one end of the biasing element177. The biasing element177can thereby urge the proximal end of the pawl178pradially outward and the distal end of the pawl178dradially inward toward the outer sleeve104and ratchet portion128. The sidewall162can include a slot184configured to receive a pin186. The pin can be anchored within a bore formed in the sidewall of the handle106such that the pin does not translate axially relative to the handle. The slot can extend axially along the distal body156to allow axial translation of the button150between a proximal position and a distal position as defined by a length of the slot184. Motion of the slot184relative to the pin186can define limits of translation of the distal body156and button150during actuation of the inserter instrument100. For example, actuation of the button150can advance the distal body156until the pin186reaches a proximal end of the slot184. Retraction of the button150can likewise move the pin186to the distal end of the slot184, and interference between the pin and the end of the slot can prevent further movement of the button150. The inserter instrument100can also include a detent188, such as a spring plunger or ball detent, received through an opening149in the handle106. The detent188, which is illustrated as a ball bearing biased radially inward by a coil spring, can engage the ratchet portion128to resist movement of the outer sleeve104relative to the handle106. This can prevent undesired proximal or distal movement of the outer sleeve104relative to the handle106, and can be particularly useful in preventing proximal movement of the outer sleeve104with the button150when the button retracts proximally after actuation. It will be appreciated that, in some embodiments, a leaf spring, a cantilevered deformable element, or other component can be used in place of the illustrated spring plunger of the instrument100. FIGS.11-16illustrate actuation of the multiple set screw insertion instrument100in greater detail. As shown inFIG.11, the button150of the multiple set screw insertion instrument100can, in an initial position, protrude proximally from the proximal end of the handle106. Once actuated, as shown inFIG.12, the resistance of the biasing element152can be overcome and the button150can move distally into the recess142of the handle106. FIGS.13-16illustrate a sequence of use of the multiple set screw insertion instrument100to insert a set screw during a procedure. Similar toFIG.11,FIG.13shows the multiple set screw insertion instrument100in an initial position with a plurality of set screws110stacked onto a distal portion of the inner driver shaft102. In this configuration, the first button150is biased to a proximal-most position and the pawl or second button178is biased to a position where its distal end engagement surface180is received within a distal-most recess130of the ratchet portion128of the outer sleeve104. The outer sleeve104is prevented from proximal movement relative to the driver shaft102and handle106by interaction between the proximal end of the outer sleeve and the handle receiving portion136, as well as by the interaction of the ratchet portion128with the pawl178, which is in turn limited by interaction of the pin186and the slot184. Accordingly, a user can urge a distal-most set screw to be placed into, e.g., a receiving member of a bone anchor to couple the set screw thereto. Axial and rotational forces can be transferred to the distal-most set screw to facilitate insertion thereof. Once the set screw110is coupled to the bone anchor, the multiple set screw insertion instrument100can be withdrawn proximally such that the distal-most set screw overcomes any resistive force from a retention feature118and comes off the driver shaft102. Alternatively or in addition, a user can depress the button150to advance the outer sleeve104relative to the driver shaft102, as described below, to aid in ejecting the distal-most set screw from the device. As shown inFIG.14, the drive feature108and the distal tip112of the inner driver shaft102can be exposed once the set screw is coupled to the bone anchor and the instrument is withdrawn proximally to decouple the distal-most set screw from the instrument. To advance the stack of set screws110distally towards the tip112, the button150can be actuated, as shown inFIG.15. Actuation of the button150can overcome the force of the biasing element152and distal advancement of the button150includes advancement of the distal body156within the lumen164relative to the handle106. Advancement of the distal body156includes advancement of the pawl178. The pawl178, which is engaged with the distal-most recess130of the ratchet portion128, urges the outer sleeve104distally along with the pawl and button150. The actuation of the button can also provide sufficient force to overcome the resistance of the detent188against movement of the outer sleeve104. Distal advancement of the outer sleeve104terminates when the pin186abuts the proximal end of the slot174and the distal-facing surface158of the button150reaches the proximal end of the recess142. In such a position, the new distal-most set screw can be positioned proximate to the distal tip112of the driver shaft108. In this orientation, as shown inFIG.15, the detent188can engage a second recess131of the ratchet portion128to again provide a resistive force against movement of the outer sleeve104. The button150can then be released and the biasing element152can return the button150to its proximal-most position. This can, in turn, urge the pawl178proximally. The resistance provided by the detent188can overcome the friction force between the pawl178and the ratchet portion128of the outer sleeve104such that the outer sleeve remains stationary relative to the handle106and the pawl178rides into the second recess131of the ratchet portion128as it moves proximally relative to the handle106and the outer sleeve104. In the absence of the detent188, the outer sleeve104could retract proximally with the pawl or button178due to the friction force between them. Once the button150returns to its proximal, initial orientation, the set screw insertion process can be repeated until the stack of set screws110along the inner driver shaft102have all been inserted into their desired locations and ejected from the insertion instrument. FIG.17illustrates the inserter instrument100following insertion of several set screws110, such that a single set screw remains disposed thereon. As shown, the pawl or second button178and the detent188are engaged with a proximal-most recess of the ratchet portion128of the outer sleeve104.FIG.18illustrates a detail view of the distal tip of the instrument100, where the set screw is engaged with the retention feature118to prevent dislodgement of the set screw therefrom. The retention feature118can include a spring clip or circlip that surrounds the distal tip112and provides a radially-outward interference fit with the female drive recess or bore formed in the set screw110. The spring clip118can be deformed to reduce its outer diameter, thereby allowing the application of sufficient force from the outer sleeve104to urge the set screw110over the clip and eject it from the instrument100. Alternate embodiments of the drive feature formed on the distal portion of the driver shaft108and the retention feature118are shown inFIGS.19-21. While a spring clip or circlip is discussed above, other embodiments are possible. As shown in these figures, the retention feature218can include a opposed ball detents that extend transversely from the distal tip of the driver shaft202. The opposed ball detents can be biased by a spring220or another biasing element. The driver shaft202can include a protruding distal tip212at the distal end of a drive feature208, as shown inFIGS.19A and19B. The protruding distal tip212can have a cylindrical profile, a diameter substantially the same as or less than a minor diameter of the drive feature208, and can include chamfered or tapered edges to help facilitate insertion of the driver shaft and set screw disposed thereabout into, e.g., a bone screw receiver head. In other embodiments and as shown inFIG.20, the driver shaft302can include a drive feature308that extends to the distal tip of the driver shaft and a retention feature318can be incorporated into the drive feature without a protruding distal tip having a different profile from the drive feature. FIGS.21and22illustrate another embodiment of a retention feature408that can be incorporated into a driver shaft402. The retention feature408can include a leaf spring or other resilient element disposed within a recess formed in the driver shaft402. In the embodiment ofFIG.21, the spring408resembles a wishbone or U-shape with a proximal end anchored within the shaft402and distal ends that protrude through opposed openings formed in the outer surface of the shaft. The protruding distal ends of the leaf spring408can be configured to retain set screws to the driver shaft via an interference fit, similar to the other retention feature embodiments described above.FIG.22illustrates an embodiment wherein a more linear spring element508provides a single protrusion from a single opening formed on the outer surface of the shaft502. In embodiments where a resilient element is anchored within a driver shaft, the shaft can be provided in two pieces, e.g., a distal piece402dand a proximal piece402pshown inFIG.21, such that the resilient element408can be positioned within recesses formed in each piece and the pieces can subsequently be coupled, e.g., at joint403by adhesive, welding, mechanical fastening, etc. Any of the above-described drive feature and retention feature embodiments can be utilized with any of the embodiments of a multiple set screw insertion instrument disclosed herein.] In addition, the various other components of the multiple set screw inserter instrument can be configured to provide different interactions with the retention features utilized to hold a set screw against inadvertent ejection from the instrument. For example, in some embodiments the device can be configured to position a set screw just proximally of a retention feature such that a distal-facing surface of the distal-most set screw abuts a portion of the retention feature. In other embodiments, however, the instrument can be configured such that a distal-most set screw is disposed over the retention feature, such that a radially-inner-facing surface of the set screw abuts a radially-outer-facing portion of the retention feature. The different configurations can be accomplished by tuning one or more of the lengths of the outer sleeve, inner shaft, ratchet portion, and first button to achieve desired spacing and advancement. Electing to use one configuration or another can produce different tactile feedback for a user. For example, in an embodiment where the distal-most set screw stacks proximally of the retention feature, a user might feel or overcome one resistance during actuation of the first button, i.e., as the distal-most set screw is advanced over the retention feature (first resistance) and a next set screw is advanced just to abut the retention feature. In another embodiment where the distal-most set screw is positioned over the retention feature, a user might feel or overcome two resistances during actuation of the first button, i.e., as distal-most set screw is ejected off the retention feature (first resistance) and a next set screw is advanced over top of the retention feature (second resistance). Any of the various embodiments disclosed herein can be configured to operate in either manner. As noted above, the outer sleeve104can include the proximal head126that can function as a retention mechanism against inadvertent separation of the outer sleeve104from the device after ejection of all set screws.FIG.23illustrates the proximal head126being used to prevent the outer shaft104from falling distally out of the central lumen134and off the inner shaft102. By way of further explanation, once the pawl or second button178is no longer engaged with the ratchet portion128of the outer sleeve104, distal advancement of the outer sleeve can continue substantially uninterrupted until the pawl178engages the proximal head126, which can have an outer diameter that is substantially the same as the outer or major diameter of the ratchet portion128in some embodiments. Friction between the engagement surface180at the distal end178dof the pawl and the proximal head126can prevent separation of the outer sleeve104from the central lumen134. In order to separate the outer sleeve104from the remainder of the instrument, a user can depress the proximal end178pof the pawl or second button178to withdraw the distal end178dradially outward and provide clearance for the proximal head126to pass distally out of the lumen134of the handle106. In some embodiments, the proximal head126can include a distal-facing surface having a tapered diameter to provide a lead-in which can allow a user to remove the outer sleeve104by application of sufficient force without separately depressing the second button178. FIGS.24-26illustrate the process of at least partially assembling the instrument and loading set screws. InFIG.24, the outer sleeve104is shown being assembled to the remainder of the instrument100. The outer sleeve104can be inserted over the driver shaft102proximally and, upon entering the lumen134of the handle106, its distal end can abut the distal end178dof the pawl or second button178. In some embodiments, the proximal end178pof the pawl or second button178can be pressed to compress the spring177, pivot the distal end178dradially outward, and allow the outer sleeve104to be inserted farther into the central lumen134, as shown inFIG.25. In some embodiments, a proximal end of the outer sleeve104and head126formed thereon can include a proximal-facing surface having a tapered diameter to provide a lead-in which can allow a user to insert the outer sleeve104by application of sufficient force without separately depressing the second button178. Once the outer sleeve104is inserted into the handle106sufficiently to clear the proximal head126past the pawl or second button178, it can continue until the ratchet portion128reaches the pawl. The proximal end178pof the pawl or second button178can then be depressed to allow the outer sleeve to continue moving proximally until the pawl reaches the distal end of the ratchet portion. At this point, the distal end of the driver shaft102will be exposed beyond a distal end of the outer sleeve104and a plurality of set screws can be inserted over the distal end of the driver shaft and stacked along the drive feature108, as shown inFIG.26. Additional details and alternate embodiments of the instrument are shown inFIGS.27-48.FIG.27, for example, illustrates a handle206that can include a silicone over-molded grip207. Any of a variety of materials can be utilized to form the handle, including metals, polymers, etc. Grip-enhancing features such as ribs, knurling, other texturing, etc., can be provided on an outer surface of the handle. FIGS.28-30illustrate an embodiment wherein a handle606includes a bore formed therein to receive a pin608that can help secure a driver shaft602to the handle. As shown, the pin608can extend transversely through the handle606of the inserter instrument600and through the inner driver shaft602to prevent unwanted rotation of the driver shaft relative to the handle during use. In embodiments where the driver shaft602is threadably coupled to the handle606, undesired relative rotation between these components during use could cause separation or adjustment of relative positioning. The use of pin608disposed through coaxial transverse bores formed in the handle606and the shaft602can prevent any such relative rotation between these components. FIG.31illustrates another embodiment of a multiple set screw insertion instrument500. The overall profile of the instrument500can be similar to an intermediate set screw driver. The inserter500can include an inner driver shaft502with a relatively long male drive feature on the distal end and a spring clip retention mechanism at the distal tip512. A number of set screws510with a female drive feature cut completely through them can be stacked on the driver along its axis. Stacking the set screws510in this way can allow the diameter of the instrument500at the distal end to remain no larger than the outer diameter OD4of the set screw, facilitating instrument compatibility without increasing instrument profile. A ratcheting outer sleeve504can advance over the inner driver shaft502, moving the next set screw to the retention feature at the distal tip512of the driver after insertion of the previous set screw. The ratcheting feature can provide a hard stop behind the set screw which can aid a user in starting to thread into the implant. A proximal handle506can have a diameter small enough to limit the amount of torque applied by a user and can contain two buttons. A first button at the proximal end can be pressed to advance the outer sleeve504and set screws510. The second, on the side of the handle506, can be pressed to return the outer sleeve504proximally and reload the instrument. A retention mechanism on the handle can temporarily hold the outer sleeve in place when the proximal button is released to allow the ratchet mechanism to advance. FIG.32illustrates an alternative view of the multiple set screw insertion instrument500. As noted above, the instrument500can reduce time and passes required to install several set screws when assembling a spinal fixation construct, savings that can be significant in long deformity correction cases where the construct spans several vertebral levels and includes several termination or fixation points between a rod or other spinal fixation element and implanted bone anchors. The relatively low profile cylindrical handle506can discourage the application of large amounts of torque to the set screws, and the reduced diameter distal portion can allow for set screw delivery through instrumentation, such as extension tubes coupled to the implanted bone anchors, etc. The above-described features of the inserter are shown inFIG.32as well, including the button550on the proximal end that controls advancing the ratcheting outer sleeve504over the inner sleeve to push the loaded set screws510distally and ready a second set screw after delivery of a first set screw. Also shown is the second button578on the side of the handle506that allows for proximal movement of the outer sleeve504to reload the device with additional set screws. Finally, the figure shows a plurality of set screws510stacked over the inner shaft at the distal end of the inserter500. FIG.33shows a partially-transparent view of the inserter500ofFIG.32to illustrate its operation and internal mechanics in greater detail. Starting at the distal end of the device, the inner shaft502includes an extended distal portion having a driver tip512geometry to allow stacking multiple set screws over the tip. As shown inFIG.34, there is a spring clip518disposed at a distal end of the driver to provide soft set screw retention due to interference between the spring clip518and set screw510. At the proximal end, a spring or other bias element552urges the button550proximally to return it after a user presses the button to advance the outer sleeve504. The proximal button550interfaces with the side button578to transfer the load from the proximal button550to the outer sleeve504. A spring plunger588prevents the ratcheting outer sleeve504from following the side button578during its return stroke with the proximal button550. FIGS.35A-35Dillustrate the set screw insertion process in cross-sectional views. A user first inserts the distal-most set screw into a receiver head or tulip of an implanted bone anchor. The user then rotates the inserter500to thread the set screw into the threaded portion of the bone anchor receiver head. The user then pulls the inserter proximally to separate it from the implanted set screw. The force of the user's pull and the secure threaded position of the set screw in the receiver head causes the set screw to overcome the distal spring clip and separate from the inserter, as shown inFIG.35B. The user can then press the proximal button550to advance the side button578and the outer ratcheting sleeve504relative to the inner shaft502and urge the stacked set screws distally until the distal-most set screw approaches the distal end of the inserter500and stops due to interference with the spring clip, as shown inFIG.35C. As the ratcheting outer sleeve504advances distally, a spring plunger588indexes from a first detent to an adjacent detent on the outer sleeve504. The spring plunger588provides enough retention force to temporarily maintain the position of the outer sleeve504when the proximal button440is released and travels with the side button578back to the initial position where they can be advanced again after delivery of another set screw, as shown inFIG.35D. FIGS.36A-36Cillustrate the set screw reloading process in cross-sectional views. As shown inFIG.36A, the ratcheting outer sleeve504can be in a distal-most position after all set screws have been delivered. To reload, a user can press and hold down the recessed side button578, as shown inFIG.36B, which can release the ratcheting outer sleeve504to move proximally when sufficient force is applied to overcome the spring plunger retention force, as shown inFIG.36C. Additional set screws510can then be loaded onto the distal drive tip portion and stacked together, as shown inFIG.36C. Once the recessed side button578is released, it will again interface with one of the ratchet teeth of the outer sleeve504to maintain its position and control advancement of the outer sleeve504when the proximal button is depressed. FIGS.37-39illustrate a cross-sectional view of another embodiment700with a side button or latch778that extends outside the handle. In particular,FIGS.38and39illustrate the relative positions of a spring plunger/ball detent788when the outer sleeve704is in a first position and after the outer sleeve704has been advanced to deliver a new set screw. FIGS.40A-48illustrate additional views of embodiments of a multiple set screw insertion instrument. More particularly,FIGS.40A-40Fillustrate various views of one embodiment of a multiple set screw insertion instrument800, including an exploded view showing outer sleeve804, inserter shaft802, handle806, dowel808for securing the inserter shaft802to the handle806, side latch878, bias spring877and pivot pin882for side latch878, proximal actuator button850, and bias spring852for actuator button. FIGS.41A-41Gillustrate various views of a set screw inserter shaft802, including its distal portion with drive tip geometry854and groove856to receive a spring clip. FIGS.42A-42Dillustrate various views of a set screw inserter handle806, including a lumen858to receive the inserter shaft, ratcheting outer sleeve, proximal button, and side latch components. FIGS.43A-43Cillustrate various views of an actuator button850, including the proximal button surface860contacted by a user and a distally-extending portion862that interfaces with the side latch or second button878.FIGS.44A-44Cillustrate various detail views of the distal end of the actuator button850that interfaces with the side latch, including a cutout864with protruding flanges866having bores868formed therein that can receive the pin882to couple the side latch or second button878to the distally-extending portion862. Also shown is a recess870that can receive the bias spring877and part of the slot872that can receive the dowel808to limit the range of motion of the button850relative to the handle806. FIGS.45A-45Eillustrate various views of the side latch878, including its proximal end878phaving a recess874to receive the bias spring877, its distal end878d, and bore876that receives pin882. FIG.46A-46Cillustrate various views of the spring clip818that retains set screws on the inserter shaft by interference fit. FIG.47A-47Dillustrate various views of the outer ratcheting sleeve804, including a proximal portion with ratchet teeth828that interface with the side latch878. Note that in this embodiment the ratchet teeth828are formed over only a portion of an outer circumference of the sleeve804. In other embodiments, as disclosed above, the ratchet teeth828can be formed around an entire circumference of the outer sleeve804. Further, in some embodiments a first set of ratchet teeth or other surface features can be formed on one side of the outer sleeve and a second set of ratchet teeth or other surface features can be formed on another side of the outer sleeve, e.g., to provide different surface features to interact with each of the second button and the detent/spring plunger. FIG.48illustrates one embodiment of a set screw810for use with the multiple set screw insertion instrument800. The set screw810can include a through-bore811formed therein with a geometry complementary to the inserter shaft distal portion854to allow the set screw to stack onto the inserter shaft802and be driven by the inserter shaft802when the inserter800is rotated. The set screw810can also include threads813formed on an outer surface thereof that can interface with threads formed on, e.g., an inner surface of a bone screw receiver head during insertion thereof using the instrument800. The instruments disclosed herein can be constructed from any of a variety of known materials. Example materials include those which are suitable for use in surgical applications, including metals such as stainless steel, titanium, nickel, cobalt-chromium, or alloys and combinations thereof, polymers such as PEEK, ceramics, carbon fiber, and so forth. The devices and methods disclosed herein can be used in minimally-invasive surgery and/or open surgery. While the devices and methods disclosed herein are generally described in the context of surgery on a human patient, it will be appreciated that the methods and devices disclosed herein can be used in any of a variety of surgical procedures with any human or animal subject, or in non-surgical procedures. The devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. In either case, however, the device can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, the device can be disassembled, and any number of the particular pieces or parts of the device can be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, the device can be reassembled for subsequent use either at a reconditioning facility, or by a surgical team immediately prior to a surgical procedure. Reconditioning of a device can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application. The devices described herein can be processed before use in a surgical procedure. First, a new or used instrument can be obtained and, if necessary, cleaned. The instrument can then be sterilized. In one sterilization technique, the instrument can be placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and its contents can then be placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation can kill bacteria on the instrument and in the container. The sterilized instrument can then be stored in the sterile container. The sealed container can keep the instrument sterile until it is opened in the medical facility. Other forms of sterilization are also possible. This can include beta or other forms of radiation, ethylene oxide, steam, or a liquid bath (e.g., cold soak). Certain forms of sterilization may be better suited to use with different portions of the device due to the materials utilized, the presence of electrical components, etc. Further features and advantages based on the above-described embodiments are possible and within the scope of the present disclosure. Accordingly, the disclosure is not to be limited by what has been particularly shown and described. All publications and references cited herein are incorporated by reference in their entirety, except for any definitions, subject matter disclaimers or disavowals, and except to the extent that the incorporated material is inconsistent with the express disclosure herein, in which case the language in this disclosure controls. Examples of the above-described embodiments can include the following:1. A surgical instrument, comprising:a shaft with a distal portion configured to drive a set screw and seat a plurality of set screws stacked against one another on the shaft;a handle coupled to the shaft;a sleeve disposed over the shaft and configured to contact a proximal-most set screw stacked on the shaft;a first button disposed in the handle and configured to advance the sleeve distally relative to the shaft by a first increment; anda second button disposed in the handle and configured to permit retraction of the sleeve proximally.2. The instrument of claim1, wherein the sleeve includes a plurality of ratchet teeth.3. The instrument of claim2, wherein the first increment corresponds to a distance between two adjacent teeth of the plurality of ratchet teeth.4. The instrument of claim2, further comprising a detent disposed in the handle that is configured to interface with the plurality of ratchet teeth to resist movement of the sleeve.5. The instrument of claim4, wherein the detent is a spring-biased ball.6. The instrument of claim2, wherein the second button is biased to contact a ratchet tooth of the plurality of ratchet teeth.7. The instrument of claim6, wherein the second button permits proximal retraction of the sleeve when the bias of the second button is overcome.8. The instrument of any of claims1to7, further comprising a spring clip disposed around a distal end of the shaft and configured to retain a set screw thereon by interference fit.9. The instrument of any of claims1to8, wherein movement of the first button causes movement of the second button.10. The instrument of claim9, wherein movement of the first button translates the second button distally.11. The instrument of claim10, wherein the first button is biased proximally such that proximal movement of the first button moves the second button proximally relative to the sleeve.12. The instrument of any of claims1to11, wherein an outer diameter of the plurality of set screws stacked on the shaft is substantially equal to an outer diameter of the sleeve disposed over the shaft.13. The instrument of any of claims1to12, wherein the sleeve further comprises a retention mechanism thereon for preventing ejection of the sleeve from the handle.14. The instrument of claim13, wherein the retention mechanism abuts the second button to retain the sleeve within the handle.15. The instrument of any of claims1to14, wherein the first button is disposed on a proximal end of the handle and the second button is disposed on a side of the handle.16. The instrument of any of claims1to15, wherein the first button is biased.17. The instrument of any of claims1to16, wherein the second button is biased.18. A surgical method, comprising:delivering a first set screw to a first implanted bone anchor using an inserter;actuating the inserter to advance a second set screw distally relative to a shaft of the inserter; anddelivering a second set screw to a second implanted bone anchor using the inserter.19. The method of claim18, wherein actuating the inserter includes depressing a first button disposed in a handle of the inserter.20. The method of any of claims18to19, wherein actuating the inserter includes advancing a sleeve disposed over the shaft distally to urge the second set screw toward a distal end of the shaft.21. A surgical method, comprising:actuating a first button disposed in a handle of an inserter;sliding a sleeve disposed over a shaft of the inserter proximally; andadvancing a plurality of set screws proximally over a distal portion of the shaft of the inserter.22. The method of claim21, wherein the first button is disposed in a side of the handle.23. The method of any of claims21to22, wherein the sleeve slides to abut a proximal wall of a recess formed in the handle.

11857226

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS FIGS.1and2illustrate a spinal distraction device100comprising a distraction rod102and a monolithic member104. The monolithic member104extends between a first end110and a second end112, and includes a hollow housing106and a solid segment108, as better appreciated in the sectional view ofFIG.3. The monolithic member104is formed as a unitary structure with no seams or joints. The distraction rod102also includes a solid segment114and a hollow segment116. Like the monolithic member104, the distraction rod102is a unitary structure with no seams or joints connecting various sub-components. Both the distraction rod102and the monolithic member104may be made from a variety of biocompatible materials, including titanium, Titanium-6Al-4V, cobalt chromium alloys, and stainless steel. Because the distraction rod102and the monolithic member104are the primary load bearing members of the spinal distraction device100, and because neither has any external circumferential weld, the spinal distraction device100is capable of withstanding improved loading challenges in comparison to standard spinal distraction devices. The solid segment108of the monolithic member104and the solid segment114of the distraction rod102have over a majority of their lengths respective diameters or thicknesses that provide a range between about 2.5 mm to about 7.5 mm, and more commonly between about 4.5 mm to about 6.35 mm. These solid segments108,114are configured to allow coupling to pedicle screws and hooks, used for attachment to portions of the vertebrae. They may also have non-circular cross-sections, and in those cases compatible with other types of pedicle screws and hooks. The respective cross-sectional views inFIG.4andFIGS.5through8show more detail of the spinal distraction device100in combination withFIGS.1through3. A magnet138is a cylindrical, radially-poled rare earth magnet, for example of neodymium-iron-boron. The magnet138is enclosed and bonded within a magnet housing140, which in turn is rotatably contained between a thrust bearing142and a radial bearing144. The magnet138may be bonded within the magnet housing140by epoxy. The magnet housing140is coupled to a lead screw134by a pin146and a coupler148. The coupler148is welded to an end150of the magnet housing140and both the coupler148and the lead screw134have holes through which the pin146is placed. The thrust bearing142is held over a centering pin154, which fits into a cavity158at an end of the hollow housing106of the monolithic member104. A radial bearing144is held within a spacer ring156. The distraction rod102has a first end118and a second end120and is configured to be telescopically expandable from the hollow housing106of the monolithic member104. A nut132is bonded within a cavity152of the hollow section116of the distraction rod102, and the lead screw134engages the nut132, so that rotation of the lead screw134in a first direction distracts or lengthens the distraction rod102and rotation of the lead screw134in a second, opposite direction retracts or shortens the distraction rod102. Two grooves122run in an axial direction along the outer wall of the distraction rod102, from a first end126(FIG.2) to a second end128(FIG.6). Pins124are spot welded or attached by other means to the wall of the hollow housing106of the monolithic member104. The pins124extend radially into the grooves122, thus assuring that the distraction rod102may not rotate in relation to the monolithic member104, while also allowing axial extension and retraction of the distraction rod102in relation to the monolithic member104. When the distraction rod102is fully retracted, a leading edge130of the pin124abuts the first end126of the groove122, keeping any further retraction from happening, and avoiding any jamming between the nut132and the lead screw134. When the distraction rod102is fully distracted, a leading edge136of the pin124abuts a second end128of the groove122, thus assuring that the distraction rod102remains at least partially within the hollow housing106of the monolithic member104. Turning toFIG.4, the magnet138, comprising a north pole160and a south pole162is shown as bonded within the magnet housing140inside the hollow housing106of the monolithic member104. Two maintenance members164are secured to the inner wall of the hollow housing106of the monolithic member104about 180° from each other along circumference. As shown, maintenance members164are curved plates, preferably made from a material such as 400 series stainless steel, which has magnetic properties that allow attraction to the poles160,162of the magnet138when closely located. This aligns the magnet138, as shown, and as the subject moves, the magnet138is not allowed to turn, but rather stays in the desired orientation. When distracting the spinal distraction device100with a strong external, moving magnetic field, however, the attraction of the magnet138to the maintenance members164is overcome easily, allowing the magnet138to turn. The maintenance members164may be resistance welded or adhesive or epoxy bonded to the inner wall of the monolithic member104. Alternatively, only one maintenance member164may be used allowing attraction to either pole160or pole162of the magnet138, but still aligning the magnet138. In applications where patient movement is not significant, it may not be necessary to include any maintenance members164. The method for assembling the spinal distraction device100is illustrated inFIG.20. In operation500, the distraction rod102and the monolithic member14are individually manufactured, for example by machining processes incorporating manual or automated lathes. Included within this manufacturing operation may be the forming of an axially-extending cavity within the monolithic member104. Post-processing may be included in this operation, for example bead blasting, passivation or anodizing. In operation502, the distraction rod102and the monolithic member104are prepared for mating. In this operation, the nut132is bonded into the distraction rod102. One or more o-rings168are placed in circumferential cavities170of the distraction rod102. One or more maintenance members164are bonded in place. A centering pin154is placed into the cavity158at the end of the hollow housing106of the monolithic member104. The centering pin154may be press fit into the cavity158, or may be bonded with an adhesive, epoxy or other joining means. The thrust bearing142is placed over the centering pin154. Ln operation504, the distraction rod102is coupled to the magnet138. In this operation, the magnet138is bonded into the magnet housing140. The magnet housing140may be a two piece assembly, for example a clamshell configuration, or bookends, or a cup/cap configuration. The radial bearing144is pressed over the end150of the magnet housing140and the coupler148is welded or bonded to the end150of the magnet housing140. The lead screw134is attached to the coupler148by the placing the pin146through the holes in the coupler148and the lead screw134. The spacer ring156is then slid into place over the coupler148and the radial bearing144. The lead screw134is screwed into the nut132. In operation506, the distraction rod102and magnet assembly131as seen inFIG.22(including magnet138/magnet housing140/radial bearing144/coupler148/lead screw134/pin146/spacer ring156/nut132/distraction rod102) are then inserted into the hollow housing106of the monolithic member104(seeFIG.22). Ln operation508, the magnet assembly131is axially locked in place within the hollow housing106of the monolithic member104. More specifically, a sleeve166having an outer diameter dose to the inner diameter of the hollow housing106of the monolithic member104is pushed into the hollow housing106and either press fit or bonded in place. It may also be resistance welded in place. The sleeve166serves to push the assembled items into their desired axial location. When. the sleeve166is bonded, it then holds the components in this configuration. The two different inner diameter portions of the spacer ring156have the appropriate diameters and lengths so that the spacer ring156does not contact the magnet housing140. In operation510, the distraction rod is rotationally locked in relation to the monolithic member. The sleeve166is supplied with holes to match those in the wall of the hollow housing106through which the pins124are placed. Alternatively, holes may be drilled through the sleeve166using the holes in the hollow housing106as a guide. The o-rings168of the distraction rod102serve to seal between the distraction rod102and the inner diameter of the sleeve166. The outer diameter of the sleeve166is sealably attached to the inner diameter of the hollow housing106via the adhesive or epoxy with which it is attached. Together, these two seals protect the inner contents: of the hollow housing106of the monolithic member104from body fluids. FIG.9Ais a view of the distraction rod102of the spinal distraction device100ofFIG.1, having a tapered portion101, and showing four landmarks172,174,176,178for scattering ultrasound. The landmarks may consist of drilled indentations or partial holes, for example drilled with a small end mill. Typical hole diameter is about 1.00 mm, and typical hole depth is about 0.75 mm. In this embodiment, the distraction rod102is formed of a metal, for example Titanium 6AL-4V, and thus is very reflective of ultrasound waves, and because of its continuity and smooth surface, a consistent bright line will be seen (see white contour of distraction rod102image inFIG.11). The landmarks172,174,176,178, for example made with the holes described, serve to break up this continuity, and give a small, but recognizable pattern in an ultrasound image. By using a different number of holes, or a varying array of holes, different image characteristics can be achieved. For example, landmark172is a single hole, while landmark174is a (in this figure) vertically arrayed pair of holes, with a distance of 1.50 mm from center to center. Landmark176consists of three vertically arrayed holes with a center-to-center distance of adjacent holes of 1.25 mm. Landmark178is two diagonally arrayed holes with a center-to-center distance of 2.75 mm. FIG.10illustrates the spinal distraction device100implanted in a subject, and attached to four vertebrae184using pedicle screws182. The spinal distraction device100has been lengthened a cumulative total amount of 17.6 mm, and landmarks172,174have been extended from the hollow housing106of the monolithic member104, while landmarks176,178are still inside. The nose188of an ultrasound probe186is coated with an ultrasound gel and pressed over the skin190. The ultrasound probe186illustrated has a linear array transducer192having a span of 40 mm, though probes are also available with spans of up to 64 mm, such as the General Electric L764. Typically, a transducer capable of being run at five to ten MegaHertz (5.0-10.0 MHz) is appropriate for the spinal distraction application, because it will be able to image the spinal distraction device100at its typical range of depths, based on patient tissue thickness. As seen inFIG.10, the ultrasound probe186is centered over the region of interest (ROI), and adjusted until an image such as that inFIG.11can be visualized. The region of interest inFIG.10includes the extended landmarks172,174and the first end110of the monolithic member104. A cable202transfers signals back and forth between the linear array transducer192and an ultrasound unit200. Signals are processed in a processor206, and can be stored in a memory208. An interface (keyboard, touch screen, etc.)210can be manipulated by the user to operate the ultrasound unit200. The resulting image may be visualized on a display204. Ultrasound waves212are transmitted to the spinal distraction device100and reflected waves214are received. In a subject180with a large amount of fat194or one in which the spinal distraction device100has been implanted significantly below the muscle196, it is possible to hold the handle198of the ultrasound probe186and compress the fat194, to bring the linear array transducer192of the ultrasound probe186closer to the spinal distraction device100, as seen inFIG.10. This assures that the desired image is located well within the display of the ultrasound unit200. InFIG.11, an ultrasound scan216was performed using a 40 mm linear array transducer at 8.0 MHz. Skin190, fat194, and muscle196covered by fascia218can be clearly seen, as can the surface of the distraction rod102, seen in bright white, and the first end110of the monolithic member104. Beneath these features is an area of ultrasonic shadowing220, due to lack of penetration of the ultrasound wave past the highly reflective titanium of the distraction rod102and the monolithic member104. A first landmark222and second landmark224are also visible on the ultrasound scan216. Because the distraction rod102and the monolithic member104move relative to each other when the spinal distraction device100is lengthened or shortened, a measurement should be taken between a landmark on the distraction rod102and a landmark on the monolithic member104. The preferred landmark on the monolithic member104is the first end110, because it is easy to appreciate the drop off in diameter from it to the distraction rod102that is seen extending from the monolithic member104. The user placed a first cursor226along the x-axis in line with the first end110, but on the y-axis at the level of the surface of the distraction rod102. Varying the y-axis location is not necessary in ultrasound units that give an x distance, y distance and a hypotenuse. A second cursor228was then moved to the desired landmark on the distraction rod102, for example landmark222or landmark224. Many ultrasound units allow for accurate on-screen caliper measurements, but alternatively, the distance between first landmark222and second landmark224, a known, controlled distance, may be used for accurate scaling. The holes depicted inFIG.9Amay be left open, or they may be filled, for example with epoxy. The epoxy may be doped with ceramic particles, in order to scatter the ultrasound in a still different manner. As an alternative to the landmarks172,174,176,178described inFIG.9A, several alternative embodiments for scattering ultrasound are presented inFIGS.9B through9D, particularly depicting tapered portion101of distraction rod102. The tapered portion101includes a taper107that extends between small diameter segment103and large diameter segment105. Large diameter segment105has a typical diameter of about 6.35 mm and small diameter segment103has a typical diameter of about 2.5 to 6.0 mm, or more particularly 4.5 mm to 6.0 mm. Between the small diameter segment103and that taper107is a radiused transition. InFIG.9B, a sharp transition111is formed in the distraction rod102at the tapered portion101. This sharp transition111provides a highly defined point in the ultrasound image for making a precision axial measurement. InFIG.9C, an embodiment is depicted which features a short ridge113extending around the distraction rod102. The ridge113also provides a highly defined point for resolving in an ultrasound image.FIG.9Ddepicts an embodiment having an ultrasound focusing feature115in place of the ridge113ofFIG.9C. The ultrasound focusing feature115, as seen in more detail inFIG.9E, includes a concave radius117extending around the distraction rod102. Ultrasound reflects at a range of angles along different axial points on the concave radius117, and the reflected ultrasound from these various reflections meets at a focal point119, thus creating a recognizable image. FIGS.12and13illustrate an intramedullary limb lengthening device300comprising a distraction rod302and a monolithic member304. The monolithic member304extends between a first end310and a second end312, as better appreciated in the sectional view ofFIG.14. The monolithic member304is formed as a unitary structure with no seams or joints. The distraction rod302has a first end318and a second end320, and is configured to be telescopically extendable and retractable within the monolithic member304. Like the monolithic member304, the distraction rod302is a unitary structure with no seams or joints connecting various sub-components. Both the distraction rod302and the monolithic member304may be made from a variety of biocompatible materials, including titanium, for example Titanium-6AL-4V, cobalt chromium alloys, and stainless steel. Because the distraction rod302and the monolithic member304are the primary load bearing members of the intramedullary limb lengthening device300, and because neither has any external circumferential weld, the intramedullary limb lengthening device300is capable of withstanding improved loading challenges in comparison to standard intramedullary limb lengthening devices. The monolithic member304contains two transverse holes301for passing bone screws, with which to attach the intramedullary limb lengthening device300to the bone. The distraction rod302contains three transverse holes303, also for the passing of bone screws. At the second end312of the monolithic member304, a coupling feature323provides an interface to releasably engage with an insertion instrument, such as a drill guide. The drill guide may include a male thread and the coupling feature323may be provided with a complementary female thread. The intramedullary limb lengthening device300comprises a magnet338which is bonded within a magnet housing340and configured for rotation between a radial bearing344and a thrust bearing342. Between the thrust bearing342and the magnet housing340are three planetary gear stages305,307,309, as seen inFIG.15A. The planetary gear stages305,307,309each comprise a sun gear311A,311B,311C and three planetary gears313, which are rotatably held within a frame315by pins317. The sun gear311is either a part of the magnet housing340, as in the case of the sun gear311A of planetary gear stage305, or a part of the frame315, as in sun gear311B or gear stage307and sun gear311C of gear stage309. The rotation of the sun gear311causes the planetary gears313to rotate and track along inner teeth321of a ring gear insert319. Each gear stage305,307,309has a gear reduction of 4:1, with a total gear reduction of 64:1. The frame315of the final gear stage309passes through the thrust bearing342and is attached to a lead screw coupler366such that rotation of the frame315of the final gear stage309causes one-to-one rotation of the lead screw coupler366. The lead screw coupler366and a lead screw358each contain transverse holes through which a locking pin368is placed, thus rotationally coupling the lead screw358to the final gear stage309. A locking pin retainer350is slid over and tack welded to the lead screw coupler366to radially maintain the locking pin368in place. The distraction rod302has an internally threaded end363, into which external threads365of a nut360are threaded and bonded, for example with epoxy. The nut360has internal threads367which are configured to threadably engage with external threads325of the lead screw358, thereby allowing rotation of the lead screw358to distract the distraction rod302in relation to the monolithic member304. Rotation of the magnet338and the magnet housing340causes rotation of the lead screw at 1/64 the rotational speed, but with significantly increased torque (64 times, minus frictional losses), and thus an amplified distraction force. O-rings362are placed in ring grooves388on the exterior of the distraction rod302and create a dynamic seal between the monolithic member304and the distraction rod302, thus protecting the internal contents from body fluids. A split washer stop364, located between the distraction rod302and the lead screw coupler366, guards against jamming that would otherwise be caused as the distraction rod302approaches the lead screw coupler366, for example if intramedullary limb lengthening device300is fully retracted with a high torque applied by an external moving magnetic field. A maintenance member346, comprising a curved plate made from 400 series stainless steel, is bonded within the inner wall of the monolithic member304by epoxy, adhesive, resistance welding or other suitable process. The maintenance member346attracts a pole of the magnet338, thus keeping the limb lengthening device300from being accidentally adjusted by movements of the patient. However, a strong moving magnetic field, such as that applied by magnetic adjustment devices known in the art, is capable of overcoming the attraction of the magnet338to the maintenance member346in order to rotate the magnet338and adjust the length of the intramedullary limb lengthening device300. Maintenance member has a thickness of approximately 0.015 inches and spans a circumferential arc of less than 180°. An exemplary arc is 99°. The method for assembling the intramedullary limb lengthening device300is illustrated inFIG.21. These assembly operations and the design of the internal components make it possible to incorporate the monolithic member304into the design of the intramedullary limb lengthening device300. In operation600, the distraction rod302and the monolithic member304are individually manufactured, for example by machining processes incorporating manual or automated lathes. Included within this manufacturing operation may be the forming of an axially-extending cavity within the monolithic member304. Post-processing may be included in this operation, for example bead blasting, passivation or anodizing. In operation602, the distraction rod302and the monolithic member304are prepared for mating. In this operation, the nut360is bonded into the distraction rod302and the o-rings362are placed into the ring grooves388as described. The maintenance member346is bonded to the monolithic member304. In operation604, the magnet338is placed into the cavity390of the monolithic member304. In this operation, the magnet338and the magnet housing340are bonded together, and then assembled with the radial bearing344into the monolithic member304(seeFIG.14). Prior to assembling the radial bearing344into the monolithic member, the longitudinal depth of the cavity390of the monolithic member304is measured, and, if necessary, one or more shims may be placed before the radial bearing344so that the resultant axial play in the assembled components is not so low as to cause binding, yet not so high as to risk disassembly. In operation606, the lead screw358is prepared for coupling to the magnet338that is in the cavity390of the monolithic member304. In this operation, the ring gear insert319is slid into the cavity390of the monolithic member304until it abuts a ledge392. First and second planetary gear stages305,307are then placed into assembly as seen inFIG.15A. The locking pin retainer350is preloaded over the lead screw coupler366prior to welding the lead screw coupler366to the final planetary gear stage309, and is then slid in place over the locking pin368after the locking pin368is placed. Final planetary gear stage309is inserted through the thrust bearing342and is welded to the lead screw coupler366, allowing for some axial play of the thrust bearing342. The split washer stop364is then placed onto the lead screw358. The lead screw358is then attached to the lead screw coupler366with the locking pin368and then the locking pin retainer350is slid over a portion of the ends of the locking pin368and tack welded to the lead screw coupler366. Thrust bearing retainers354,356are two matching pieces which form a cylindrical clamshell around the thrust bearing342and the lead screw coupler366. The internal diameter of the monolithic member304is tinned with solder, as are the outer half diameter surfaces of each of the thrust bearing retainers354,356. In operation608, the thrust bearing retainers354,356are then damped over an assembly327(illustrated inFIG.23) containing the thrust bearing342, lead screw coupler366, planetary gear stage309, and lead screw358, and the thrust bearing retainers354,356and the assembly327are pushed together into place within the monolithic member with a cannulated tool329(seeFIGS.23and24). The cannulated tool329has a chamfered end331which pushes against a matching chamfer352in each of the thrust bearing retainers354,356, thus forcing them outward against the inner diameter of the monolithic member304. The sun gear311C of the final planetary gear stage309engages with the planet gears313of the final planetary gear stage309and then chamfered edges394of the thrust bearing retainers354,356are pushed against a chamfer348of the ring gear insert319with a pre-load force. In operation610, the thrust bearing342and the magnet338are axially retained. In this operation, the thrust bearing retainers354,356are soldered to the monolithic member304at the tinned portions, thus maintaining the pre-load force in place. This may be accomplished using induction heating. The friction of the ledge392and the chamfered edge394against opposing ends of the ring gear insert319, as well as the wedging between the chamfered edge394and the chamfer348, hold the ring gear insert319rotationally static in relation to the monolithic member304. Alternatively, the ring gear insert319may have a keyed feature that fits into a corresponding keyed feature in the monolithic member304, in order to stop the ring gear insert319from being able to turn in relation to the monolithic member304, in case the friction on the ends of the ring gear insert319is not sufficient to hold it static. In operation612, the distraction rod302is engaged with the lead screw358. In this operation, an assembly tool consisting of a high speed rotating magnet is used to make the magnet338and thus the lead screw358rotate and the distraction rod302is inserted into the monolithic member304while the lead screw358engages and displaces in relation to the nut360of the distraction rod302. After the distraction rod302is inserted into the monolithic member304as described and retracted at least somewhat, the distraction rod302is still free to rotate in relation to the monolithic member304. For the stability of the bone pieces being distracted, it is desired to inhibit rotation between the distraction rod302and the monolithic member304, and this final portion of the assembly process is described in relation toFIGS.16and17. In operation614, the distraction rod302is rotationally locked in relation to the monolithic member304. In this operation, an anti-rotation ring370is placed over the distraction rod302by engaging protrusions374, one on each side, into grooves372extending along the distraction rod302and then by sliding the anti-rotation ring370up to a tapered inner edge376of the monolithic member304. The anti-rotation ring370and the distraction rod302are then rotated until guide fins382can be inserted into guide cuts380in an end of the monolithic member304. The anti-rotation ring370is now axially snapped into the monolithic member304as a flat edge384of the anti-rotation ring370is trapped by an undercut378. The undercut378has a minimum diameter which is less than the outer diameter of the flat edge384of the anti-rotation ring370, and is temporarily forced open during the snapping process. As assembled, the anti-rotation ring370, the monolithic member304and the distraction rod302are all held rotationally static in relation to each other. In addition, when the intramedullary limb lengthening device300reaches maximum distraction length, the ends386of grooves372abut the protrusions374, and thus the distraction rod302is kept from falling out of the monolithic member304. An alternative embodiment of the intramedullary limb lengthening device300ofFIGS.12-15Ais shown in a sectional view inFIG.15B. Much of this embodiment is identical to the embodiment ofFIGS.12-15A, however the differences are hereby described. The embodiment does not have thrust bearing retainers354,356, but instead incorporates a thrust bearing ferrule335having an external tapered end347. A thrust bearing retainer337, a locking pin retainer341and the thrust bearing ferrule335are placed over the thrust bearing342and a lead screw coupler339, and the final planetary gear stage309is inserted through the thrust bearing342and is welded to the lead screw coupler339. As shown inFIG.15D, the locking pin retainer341has a relief361to allow the passage of the locking pin368. After the locking pin368is placed, the locking pin retainer341is rotated so that the relief361is no longer directly over the locking pin368and the locking pin retainer341is tack welded or secured by other methods to the lead screw coupler339, thus retaining the locking pin368. These assembled components are then inserted into the cavity390of the monolithic member304, where the final planetary gear stage309is coupled to the other planetary gear stages305,307and the magnet338. In this embodiment, a ring gear insert333(FIG.15C) has an indentation351on each side. A tab349on each side of the thrust bearing ferrule335inserts into each indentation351, in order to inhibit rotation of the ring gear insert333in relation to the monolithic member304, once the thrust bearing ferrule335is engaged into the monolithic member304. Also in this embodiment, the monolithic member304contains internal threading343. The engagement of the thrust bearing ferrule335is achieved by tightening external threading345of the thrust bearing retainer337into the internal threading343of the monolithic member304. A tool (not shown) is engaged into cut outs357on each side of the thrust bearing retainer337and is used to screw the thrust bearing retainer337into the internal threading343of the monolithic member304. As shown inFIG.15B, this wedges an internal taper353of the thrust bearing retainer337against the external tapered end347of the thrust bearing ferrule335, allowing the thrust bearing ferrule335to apply a controlled load on the ring gear insert333, locking the ring gear insert333axially and rotationally in relation to the monolithic member304. The thrust bearing retainer337contains an axial split on the opposite side (not shown). The split in the thrust bearing retainer337allows the outer diameter of the thrust bearing retainer337to be slightly reduced (by compression) while it is inserted into the monolithic member304, prior to being threaded, so that the internal portion of the monolithic member304is not scratched during insertion. A ledge355is visible on the lead screw coupler339inFIG.15D. As noted earlier, the split washer stop364butts up against this ledge355to prohibit jamming when the distraction rod302is retracted completely. FIGS.18and19illustrate an external adjustment device478configured for applying a moving magnetic field to allow for non-invasive adjustment of the intramedullary limb lengthening device300by turning the magnet338within the intramedullary limb lengthening device300.FIG.18illustrates the internal components of the external adjustment device478, and for clear reference, shows the magnet338of the intramedullary limb lengthening device300, without the rest of the assembly. The internal working components of the external adjustment device478may, in certain embodiments, be similar to that described in U.S. Patent Application Publication No. 2012/0004494, which is incorporated by reference herein. A motor480with a gear box482outputs to a motor gear484. The motor gear484engages and turns a central (idler) gear486, which has the appropriate number of teeth to turn first and second magnet gears488,490at identical rotational speeds. First and second magnets492,494turn in unison with the first and second magnet gears488,490, respectively. Each magnet492,494is held within a respective magnet cup496(shown partially). An exemplary rotational speed is 60 RPM or less. This speed range may be desired in order to limit the amount of current density induced in the body tissue and fluids, to meet international guidelines or standards. As seen inFIG.18, the south pole498of the first magnet492is oriented the same as the north pole404of the second magnet494, and likewise, the first magnet492has its north pole400oriented the same as the south pole402of the second magnet494. As these two magnets492,494turn synchronously together, they apply a complementary and additive moving magnetic field to the radially-poled magnet338, having a north pole406and a south pole408. Magnets having multiple north poles (for example, two) and multiple south poles (for example, two) are also contemplated in each of the devices. As the two magnets492,494turn in a first rotational direction410(e.g., counter-clockwise), the magnetic coupling causes the magnet338to turn in a second, opposite rotational direction412(e.g., clockwise). The rotational direction of the motor480is controlled by buttons414,416. One or more circuit boards418contain control circuitry for both sensing rotation of the magnets492,494and controlling the rotation of the magnets492,494. FIG.19shows the external adjustment device478for use with an intramedullary limb lengthening device300placed in the femur. The external adjustment device478has a first handle424attached to a housing444for carrying or for steadying the external adjustment device478, for example, steadying it against an upper leg420, as inFIG.19, or against a lower leg422in the case that the intramedullary limb lengthening device300is implanted in the tibia. An adjustable handle426is rotationally attached to the external adjustment device478at pivot points428,430. The pivot points428,430have easily lockable/unlockable mechanisms, such as a spring loaded brake, ratchet or tightening screw, so that a desired angulation of the adjustable handle426in relation to the housing444can be adjusted and locked in orientation. The adjustable handle426is capable of being placed in multiple positions. InFIG.19, adjustable handle426is set so that the apex432of loop434rests against housing end436. In this position, patient438is able to hold onto one or both of grips440,442while the adjustment is taking place. Patient is able to clearly view a control panel446including a display448. In a different configuration from the two directional buttons414,416inFIG.18, the control panel446includes a start button450, a stop button452and a mode button454. Control circuitry contained on circuit boards418may be used by the surgeon to store important information related to the specific aspects of each particular patient. For example, in some patients an implant may be placed antegrade into the tibia. In other patients the implant may be placed either antegrade or retrograde into the femur. By having the ability to store information of this sort that is specific to each particular patient within the external adjustment device478, the external adjustment device478can be configured to direct the magnets492,494to turn in the correct direction automatically, while the patient need only place the external adjustment device478at the desired position, and push the start button450. The information of the maximum allowable distraction length per day and per distraction session can also be input and stored by the surgeon for safety purposes. These may also be added via an SD card or USB device, or by wireless input. An additional feature is a camera at the portion of the external adjustment device478that is placed over the skin. For example, the camera may be located between the first magnet492and the second magnet494. The skin directly over the implanted magnet338may be marked with indelible ink. A live image from the camera is then displayed on the display448of the control panel446, allowing the user to place the first and second magnets492,494directly over the area marked on the skin. Crosshairs can be overlayed on the display448over the live image, allowing the user to align the mark on the skin between the crosshairs, and thus optimally place the external adjustment device478. As described in conjunction with the spinal distraction device100ofFIGS.1through8and with the intramedullary limb lengthening device300ofFIGS.12-17, load-bearing orthopedic devices can be constructed which, by incorporating a monolithic member104,304having a unitary structure with no seams or joints, have improved strength over prior art devices having welded joints. Four point bend testing of monolithic members304constructed in accordance with the methods described herein showed that a strength improvement of 38% was achieved as compared to data obtained on elongate members which incorporated a housing having a laser weld. Additionally, the embodiments for the spinal distraction device100and the intramedullary limb lengthening device300described herein have features which inhibit rotation between the distraction rod102,302and the monolithic member104,304, maintain the magnet138,338in its axial position in relation to the monolithic member104,304, and keep the distraction rod102,302from falling out of the monolithic member104,304by providing a stopping mechanism at full extension. All of these features were not achievable in prior devices without resorting to welds which decreased the overall strength. While embodiments of the present invention have been shown and described, various modifications may be made without departing from the scope of the present invention. For example, the magnets in the devices may be replaced by any type of drive member, for example motors or shape memory mechanisms. They may also be replaced by a subcutaneous lever that allows the device to be non-invasively adjusted. The invention, therefore, should not be limited, except to the following claims, and their equivalents.

11857227

DETAILED DESCRIPTION Turning now toFIGS.1aand1b, an exemplary embodiment of an orthopedic fastening system10includes an orthopedic locking screw12configured to be operably secured through a bore14in an orthopedic implant16(not shown), such as a bone nail (e.g., intramedullary nail) or plate, in order to lock the orthopedic implant into a selected position relative to one or more bones or bone portions. The orthopedic locking screw12is in certain implementations configured to provide a press-fit, including a friction fit, with the implant to prevent or substantially eliminate movement of the orthopedic implant relative to the orthopedic locking screw12, such as radially in relation to the axis of the screw and/or angularly, in a selected position relative to the orthopedic implant. The orthopedic locking screw12includes a shaft18extending axially between a first end20and a second end22. The shaft18may have an elongate, tubular form. The profile of the shaft may be circular or polygonal, such as rectangular, square, or hexagonal. The shaft18may be generally cylindrical, having a substantially constant diameter extending between the first and second ends20,22. However, in some arrangements, the shaft may have a tubular form with non-circular cross-sections and/or may have varying outside cross-sectional widths. The shaft18can have different shapes as long as the orthopedic locking screw12is able to operably engage a bore in the implant in such a manner as to be able to retain and, optionally, advance the orthopedic locking screw12in and/or through the bore of the orthopedic implant. A drive member24is disposed at the second end22of the shaft18. The drive member24may take any form capable of operably engaging with a rotational drive (not shown), such as a screw driver or wrench, so as to be able to rotate the orthopedic locking screw12about the axis of the shaft in order to operably engage the orthopedic locking screw12with bone and/or the implant. InFIGS.1aand1b, the drive member is in the form of a recess, such as a socket, for receiving a rotational member. However, the drive member24is not limited to a particular shape or drive arrangement. For example, the drive member24may have other shapes, such as having a square or hexagonal circumference for being received in a wrench or a socket, or may have a socket adapted to receive a square or hexagonal drive, or a slot for receiving a screw driver. A casing26is secured as a separate component around an outer surface of the shaft18. The casing26may be secured to the shaft18so as to be rotationally fixed with respect to the shaft18. The casing26is formed of a deformable material, such as plastic or a relatively soft metal. The casing may be formed of a rubbery material, such as rubber or silicon. The material forming the casing26and/or the shaft18may be a bio-compatible material suitable for use as an implant in the human body. The material of the casing26is softer than the material of the shaft18. The material of the shaft18can be a plastic, metal or ceramic. The casing26is secured to the shaft18in a manner configured to prevent one or both of axial slipping and radial slipping along the shaft18when operatively engaging the implant (i.e., a bore thereof). For example, the casing26may be secured by molding to the shaft18, adhesive, welding, and/or with mechanical fasteners. The casing26may be prevented from circumferential slipping by mechanical interaction with a polygonal shaped profile of the shaft18. The casing26may have an outer surface that is sized slightly larger than the smallest inside opening space through the implant so as to form a press fit with the implant. The press fit reduces or eliminates radial shifting and movement of the orthopedic implant relative to the axis of the locking screw12, thereby minimizing the play between the locking screw, the orthopedic implant, and/or bone portions connected thereby. The press fit optionally also may angularly lock the orthopedic locking screw12in a selected position in the implant. The casing26has an outer cross-sectional width W1that is larger than a corresponding largest outer cross-sectional width W2of the shaft18between the first end20and the second end22. The press-fit may include axial and/or radial components. The casing26extends axially along a medial portion of the shaft18. In more detail, the casing26extends between a first end28and a second end30. The first end28is located proximate the first end20of the shaft18. The second end30is disposed proximate the second end22of the shaft18. The casing26has a continuous unbroken outer circumferential surface extending between the first and second ends28and30. The first end28of the casing26is spaced axially from the first20of the shaft18. The second end30of the casing26is spaced axially from the second end22of the shaft18. The outer surface of the casing26may be substantially smooth. Additionally or alternatively, one or more external engagement features32, such as ribs, tabs, or threads may optionally be formed on the outer surface of the casing26configured to operably engage, for example, with internal thread features of a bore of the implant. The engagements features32may define a helical path or may not form a helical path, and may take any form arranged to operably engage a thread feature of the implant bore so as to advance and/or retain the casing and the shaft therein. The engagement features32may take the form of one or more external threads. In the present embodiment, the engagement features32are formed as a deformable thread32described elsewhere herein. The deformable thread32is disposed along the outer surface of the casing26. The deformable thread32is an exterior thread having a major diameter Dmaj and a minor diameter Dmin in a manner well understood in the threading art. The shaft18and the casing26are shown having generally cylindrical shapes with circular cross-sections (as viewed transverse to the axis of the shaft18). However, it is understood that the shaft18and casing26are not limited to cylindrical shapes, but may have other tubular and/or non-cylindrical shapes. The use of the terms major and minor diameter are therefore not to be construed as limiting to purely circular cross-sections, but refer rather to the diameter of the circumscribed circle upon, for example, rotating the shaft18about its longitudinal axis. The deformable thread32may be a continuous thread or it may be a discontinuous thread defined by a plurality of thread portions with intermittent breaks or interruptions therebetween. For example, if the casing26has a polygonal cross-section, such as a generally square cross-section, the deformable thread32may be defined by intermittent thread portions defined through the outside corners of the cross-section. Of course, other shapes and arrangements are also possible with the same understanding. In the present embodiment, the deformable thread32is a continuous thread extending from adjacent the first end28of the casing26to the second end30of the casing26as shown inFIG.1a. The major diameter Dmaj and the minor diameter Dmin of the deformable thread32are both constant along the length of the deformable thread32. A forward external thread34or other type of thread engagement feature, such as ribs, tabs, or grooves, is disposed on the first end20of the shaft18. The forward external thread34may be sized to engage a complementary thread feature of an implant bore14. In the present embodiment, the forward external thread32may have a major diameter (i.e., outer diameter) W2that is smaller than the smallest inside cross-sectional opening through the implant bore14, such as a minor diameter of internal threads in the bore14. In other words, the inside diameter of the bore14of the orthopedic implant16is larger than the outer diameter W2of the forward external thread34. The forward external thread34operably engages with a bore through bone disposed behind the bore14of the implant16. In this manner, the forward external thread34is used to draw the shaft18and the casing26through the implant bore14. As the casing26advances through the implant bore14, the outer surface of the casing26, such as the deformable thread32, deformably engages with the inner surface or surfaces of the implant bore14. The deformable engagement creates a press-fit pressure, for example with a friction fit, that stabilizes the orthopedic bone screw12angularly and/or axially in a selected position in the implant16. In the present embodiment, the forward external thread34is disposed on the shaft18between the first end28of the casing26and the first end20of the shaft18. A rear external thread36is disposed on the shaft18between the second end30of the casing26and the second end22of the shaft18. In some arrangements, either or both of the external threads34,36may be omitted. The forward external thread34is spaced apart axially from the rear external thread36. The forward external thread34is spaced axially from the first end28of the casing26. The rear external thread36is spaced axially from the second end30of the casing26. However, in other arrangements, the forward external thread34may extend to and/or underneath the first end28of the casing26and/or the rear external thread36may extend to and/or underneath the second end30of the casing26. In yet further arrangements, the forward and rear external threads34and36may be connected as part of a single thread with a middle portion disposed partially or wholly underneath (i.e., radially inwardly from) the casing26. The forward external thread34has a major diameter W2that is smaller than the minor diameter Dmin of the deformable thread32. In other words, the outer diameter W1of the deformable thread32of the casing26is larger than the outer diameter W2of the forward external thread34. The rear external thread36may have a major diameter W3equal to or larger or smaller than the forward external thread34. In the present embodiment, the rear external thread36has a major diameter W3larger than the forward external thread34as shown inFIGS.1aand1b. The rear external thread36is configured to engage a bore through the bone behind the advancement of the sheath26. In one arrangement, the major diameter W3, W2of one or both of the rear external thread36and the forward external thread34is the same as the major diameter Dmaj of the deformable thread32along a cylindrical path. In the present embodiment, the outer diameter W3of the rear external thread36is larger than the outer diameter W1of the deformable thread32of the casing26. The forward external thread34may have a pitch that is different from a pitch of the deformable thread32of the casing28. In the present embodiment, the forward external thread34has a pitch that is larger than the pitch of the deformable thread32of the casing28. Alternatively, the pitch of the forward external thread34can be smaller than the pitch of the deformable thread32. The rear external thread36has a pitch that is equal to the pitch of the forward external thread34. Thus, the rear external thread36can have a pitch that is smaller or larger than the pitch of the deformable thread32of the casing28. The deformable thread32may have a variable pitch along the length of the casing26. For example, the deformable thread32has a smaller pitch at or near the first end28of the casing26and increases continuously to a larger pitch at or near the second end30of the casing26. However, other pitch variations capable of causing an axial press-fit pressure with internal threads of the bore14of the implant16are also possible and contemplated, such as a discontinuous variation of the pitch, a pitch that decreases from the first end28toward the second end30, or other pitch variations. In the present embodiment, the pitch of the deformable thread32of the casing26is constant along the length of the deformable thread32. A pitch difference between the forward external thread34and the deformable thread32and also a variable pitch of the deformable thread32may in certain variants be exploited to reduce or eliminate the amount of shifting and movement between parts of the orthopedic fastening system10. As an example, in certain variants a press-fit pressure may thus obtained or increased. As shown inFIGS.1aand1b, a tip38is disposed at the first end20of the shaft18. The tip38tapers to a point or, alternatively, to a blunt nose, such as a rounded, flat, or truncated nose. The tip38includes a self-tapping feature40for tapping a bore into bone. The self-tapping feature40includes at least one, and optionally a pair of diametrically opposite axial grooves42extending along the tip40through at least a portion of the forward external thread34as shown inFIG.1b. The axial grooves42may be at least partially helically wound. The axial grooves42may act to scoop away bone or other material as the orthopedic locking screw12is rotated and advanced into the bone. The drive member24includes a head44disposed at the second end22of the shaft18. The head44is configured to engage with a rotational drive member. For example, the head44includes a polygonal socket46configured to receive a complementary rotary drive (not shown). Other drive configurations may also be used. The head44has a larger diameter than the adjacent second end22of the shaft18, thereby forming a shoulder48extending radially outwardly from the outer circumferential surface of the second end22of the shaft18to the outer circumferential surface of the head44. In other arrangements, the head44may be circumferentially smaller than or the same size as the second end22of the shaft18and/or may include circumferential engagement surfaces, such as having a hex head outer circumferential shape. The head44is not limited to the arrangements expressly described, and other arrangements for operably engaging a rotational drive tool may be used. The casing26is secured to the outer surface of the shaft18in any manner sufficient to prevent rotational and/or axial sliding of the casing26relative to the shaft18, for example, when the casing26is rotationally engaged against an outer or internal surface of the bore14of the implant16. In the present embodiment, the casing26is molded directly against the outer surface of the shaft18so as to provide a molded securement between the casing26and the outer surface of the shaft18. Alternatively, the casing26may be adhesively secured to the outer surface of the shaft18with an adhesive. Further, the casing26may, alternatively or in addition, be mechanically secured to the outer surface of the shaft18, for example, by engagement with projections or other surface features with the shaft18, such as threads, ribs, tabs, grooves, and/or scoring. In the present embodiment as shown inFIGS.1aand1b, the shaft18has a thread50for securing the casing26to the shaft18.FIG.1billustrates the orthopedic locking screw12without the casing26. The thread50of the shaft is substantially equal to the deformable thread32of the casing. Further the thread50may have substantially equal dimensions and/or pitch as the deformable thread32of the casing. The casing26directly engages the thread50of the shaft18, e.g., is directly molded against the thread50of the shaft18. By molding or adhering the casing26to the shaft18, the thread50may act as a preform to form the basic structure of the deformable thread32. Turning now toFIGS.2aand2b, another embodiment of an orthopedic locking screw52is shown. The orthopedic locking screw52is similar to the orthopedic locking screw12in that it includes a shaft18extending between first and second ends20and22, a drive member24disposed at the second end22, and a casing26secured around an outer surface of the shaft18, wherein the casing26includes a deformable thread32and the shaft18includes a forward and rear external thread34,36. A description thereof is not repeated here for brevity, but reference is made to the previous description in view of the following additional or alternative arrangements. One difference between orthopedic locking screw52and orthopedic locking screw12is that the shaft18of orthopedic locking screw52includes at least one groove54.FIG.2billustrates the orthopedic locking screw52without the casing26. In the present embodiment as show inFIG.2b, the shaft18of orthopedic locking screw52has four grooves54. Alternatively, the shaft18of orthopedic locking screw52may include one, two, three or more grooves54. The groove54extends circumferentially around and axially along the outer surface of the shaft18. The casing26is disposed in the groove52such that the groove52helps secure the casing26on the outer surface of the shaft18. The groove54may have a continuous polygonal core profile, such as a rectangle, square, or hexagon, a continuous arcuate profile, such as circular or oval, or both polygonal and arcuate profiles. The shaft18comprises a polygonal or other non-circular profile in cross-section (i.e., cross-sectional shape transverse to the longitudinal axis of the shaft) that prevents the casing26from rotationally slipping on the shaft18. In the exemplary arrangement ofFIG.2b, the grooves52have a circular core profile56. The circular core profile56extends continuously along the entire axial length of the groove54. In some arrangements, the groove54and/or other portions of the shaft18may have other core profile shapes, such as star or gear tooth shape formed by elongate ribs or other shaped protrusions or recesses. The groove54has a smaller outside diameter than the adjacent portions of the shaft18. The grooves54in this arrangement are spaced around the outer circumference of the shaft18. Alternatively, one groove may extend radially completely around the outer circumference of the shaft18. As shown inFIG.2b, the grooves54extend axially from a first radial shoulder58proximate the first end20of the shaft18to a second radial shoulder60proximate the second end22of the shaft18. The entire axial length of the casing26is received within the grooves54. The first end28of the casing26abuts the first radial shoulder58. The second end30of the casing26abuts the second radial shoulder60. Thus, the radial shoulders58and60mechanically retain the casing26axially fixed along the length of the shaft18. The casing26has a thickness that is larger than the radial dimension of the groove54such that the outer circumferential surfaces of the casing26project radially beyond the outer circumferential surfaces of the adjacent first and second ends20and22of the shaft18, in accordance with the previous description. A radially inner surface of the casing26may additionally or alternatively be secured against the radially outer surface of each groove54by other fastening connections, such as an adhesive, or an over molded connection, welds, or mechanical fastening features. FIG.3illustrates another embodiment of an orthopedic locking screw62. The orthopedic locking screw62is similar to the orthopedic locking screw12in that it includes a shaft18extending between first and second ends20and22, a drive member24disposed at the second end22, and a casing26secured around an outer surface of the shaft18, wherein the casing26includes a deformable thread32and the shaft18includes a forward and rear external thread34,36. The descriptions thereof are not repeated here for brevity, but reference is made to the previous description in view of the following additional or alternative arrangements. One difference between orthopedic locking screw12ofFIGS.1aand1band the orthopedic locking screw62shown inFIG.3is that shaft18includes projections64. The projections64are disposed on the outer surface of the shaft18. The projections64may be arranged on the shaft18along a helical curve around the shaft18, e.g., in similar fashion as a thread or thread sections. The projections64may be produced by forming or cutting a thread on the shaft18and then, milling of portions of the thread, thus forming gaps within the thread. The casing26is secured to and rotationally fixed around the outer surface of the shaft18, wherein the casing26is formed around the projections64. In the present embodiment, the projections64and deformable protrusions of the casing28are alternately arranged on the outer surface of the shaft18. The projections28and the casing26together form a thread-like feature along the shaft18as shown inFIG.3. In the present embodiment, a partially deformable thread66is thus formed by the protrusions of casing26and the projections64of shaft18. In addition, shaft18of orthopedic locking screw62may have one or more of grooves54as described above and as shown inFIGS.2aand2b. In such an embodiment, the projections64can be arranged along the shaft18between the grooves54. Turning now toFIGS.4to6, the orthopedic fastening system10is shown. The orthopedic fastening system10includes orthopedic locking screw12as shown inFIGS.4and6and an exemplary orthopedic implant14as shown inFIGS.5and6. Orthopedic locking screw52or62as described above could also be used in combination with the orthopedic implants of any of the drawings shown herein as part of this orthopedic fastening system. The orthopedic implant14may have any of various specific forms. FIG.4illustrates orthopedic locking screw12in a side view. As described above with reference toFIGS.1aand1b, orthopedic locking screw12includes the shaft18extending between first and second ends20and22, the drive member24disposed at the second end22, and the casing26secured around an outer surface of the shaft18, wherein the casing26includes the deformable thread32and the shaft18includes the forward and rear external thread34,36. A description thereof is not repeated here for brevity, but reference is made to the previous description in view of the following additional or alternative arrangements. The first end28of the casing26is tapered radially inwardly, as at68, toward the outer diameter of the front end20of the shaft18immediately adjacent the first end28of the casing26. In this arrangement, the deformable thread32runs out at a location along the taper68before reaching the first end28, such that the deformable thread32has a first end spaced along the taper68adjacent to and spaced from the first end28of the casing26. Alternatively, the thread32may run entirely to the first end28of the casing26. In some arrangements, the taper68is such that there is a smooth transition between the first end28of the casing26and the shaft18. In other arrangements, the first end28of the casing26may have a larger diameter than the adjacent portion of the shaft18so as to form a radially stepped transition. The remaining portion of the outermost diameter of the casing26may be substantially cylindrical from the taper68to the second end30or may have a different taper or other width variations. Alternatively, the outermost diameter of the casing26may be substantially cylindrical along the entire axial length between the first end28and the second end30. In one exemplary embodiment, the orthopedic locking screw12preferably has an overall length of between 125 mm and 5 mm, and more preferably between approximately 70 mm and 50 mm. The casing26preferably has a length of between 100 mm and 3 mm and more preferably between approximately 40 mm and 30 mm. The casing26preferably has an outside diameter of between 52 mm and 0.9 mm, more preferably between 12 mm and 5 mm, and most preferably between approximately 6 mm and 4 mm, and in some arrangements approximately 5.2 mm or 5.3 mm. In one arrangement, the deformable thread32preferably has a major diameter of between 51 mm and 0.8 mm, more preferably between 11 mm and 4 mm, and most preferably between approximately 6 mm and 4 mm, and in some arrangements approximately 5.3 mm or 5.5 mm, a minor diameter of between 50 mm and 0.7 mm, more preferably between 10 mm and 2 mm, and in some arrangements approximately 4.3 mm or 4.5 mm. In a further arrangement, the deformable thread32may have a variable pitch that varies continuously along the axial length of the casing from between approximately 0.5 to 2 threads/mm adjacent the first end28to between approximately 0.1 to 1 threads/mm at the second end30. Preferably, the deformable thread32may have a constant thread pitch along the axial length of the casing between 0.5 to 2 threads/mm, more preferably between 0.9 and 1.5 threads/mm, and in some arrangements approximately 1.25 threads/mm or 1.3 threads/mm. The shaft18may have an average diameter of between 50 mm and 0.7 mm, more preferably between 20 mm and 3 mm, and in some arrangements between approximately 4.9 mm and 5.1 mm. Either or both of the forward external thread34and the rear external thread36may have a major diameter of between 52 mm and 0.9 mm, more preferably between 12 mm and 4 mm, and most preferably between approximately 7 mm and 5 mm, and in some arrangements approximately 5 mm or 6 mm. Further, either or both of the forward external thread34and the rear external thread36may have a constant thread pitch along the axial length thereof between 0.5 to 2 threads/mm, more preferably between 1.0 and 1.9 threads/mm, and most preferably between approximately 1.7 and 1.8 threads/mm and in some arrangements approximately 1.75 threads/mm. However, the specific dimensions provided herein are only exemplary of one optional exemplary arrangement, and the invention is not limited to the specific dimensions provided. FIG.5shows a perspective partial view of the orthopedic implant16having a bore14. The orthopedic implant16may be formed of a biocompatible material suitable and/or approved for use as an implant inside a human body. In some arrangements, the orthopedic implant16is formed of metal, plastic, and/or ceramic. The orthopedic implant16may be any type of orthopedic implant. Some exemplary types of orthopedic implants include plates and bone nails like intramedullary nails. The bore14of the orthopedic implant16may be smooth and/or include an internal surface feature, such as an internal thread, having a radially internal arrangement suitable for operably engaging external threads or any other engagement structures on the locking screw12, for example configured to retain and, optionally, advance any of the orthopedic locking screws disclosed herein upon rotating the locking screw inside the bore14. Thus, for example, the bore14may in some embodiments be formed of a thin bore that does not have helical threads but has edges that interact with external helical threads or thread-like features to advance and/or retain an orthopedic locking screw. In other embodiments, the bore14may include one or more radially internally projecting protrusions that are similarly able to operably interact with external helical threads or thread engagement features. In yet further embodiments, the bore14may include one or more helical internal threads, either alone, or in combination with other thread-like features. In the present embodiment as shown inFIG.5, the orthopedic implant16includes one exemplary bore14, although the orthopedic implant16may include any number of such bores14. The bore14is a through bore extending transversely through the orthopedic implant16from a first side to a second side. The bore14is internally threaded, including an internal thread70helically wound along an inner circumferential surface of the bore14. Further, the bore14includes a circumferential rib72extending around and projecting radially inwardly from the inner circumferential surface of the bore14. The circumferential rib72is spaced medially through the bore14, such as being spaced half way between the first and second sides of the bore14. The internal thread70traverses the inner circumferential surface of the circumferential rib72. Further, the orthopedic implant16includes a channel74in the direction of its longitudinal axis. The channel74crosses the threaded bore14, i.e., the channel opens out into bore14as shown inFIG.5. FIG.6illustrates orthopedic locking screw12ofFIG.4inserted into the bore14of orthopedic implant16ofFIG.5as a perspective transverse cross-sectional partial view. In the present arrangement, the forward external thread34is sized so as to not operably engage the bore14of the orthopedic implant16but is configured mainly for engaging with bone on either or both sides of the bore14(not shown inFIG.6). For example, the major diameter of the forward external thread34is smaller than the minor diameter of the internal thread70so that the forward external thread34does not operably engage the internal thread70but can be pushed through the bore14without interference. In other arrangements, however, the forward external thread34may be sized to operably engage the bore14. For example, the major diameter of the forward external thread34may be larger than a minimum opening width through the bore14. The deformable thread32is configured to engage with the bore14so as to operably retain the shaft18in the bore14with a press-fit and/or mechanical interfit. As shown inFIG.6, the deformable thread32is configured to engage with one or more interior thread features, such as one or more interior threads70, in the bore14in a manner configured to cause at least one or both of a radial press-fit pressure and an axial press-fit pressure. The deformable thread36optionally is configured to at least partially receive the inner circumference of the circumferential rib72within the groove of the thread. However, it is not necessary for the deformable thread32to perfectly match the configuration of the internal thread70because it can deform to adjust to the internal thread70. In present arrangement, the internal threads70axially engage and increasingly deform the axial walls of the deformable thread32as the thread32is advanced through the bore14, thereby giving rise to a variable, and in this case, increasing, axial press-fit pressure as the orthopedic locking screw12is advanced through the bore14. The insertion and locking process of the orthopedic locking screw12will be described with reference toFIGS.7and8below in more detail. The press-fit is configured to prevent or substantially eliminate movement of the orthopedic implant16relative to the orthopedic locking screw12, such as radially in relation to the shaft18and/or angularly, in a selected position relative to the orthopedic implant16. Thus, the press fit reduces or eliminates radial shifting and movement of the orthopedic implant16relative to the axis of the locking screw12, thereby minimizing the play between the locking screw, the orthopedic implant, and/or bone portions connected thereby. The press fit optionally also may angularly lock the orthopedic locking screw12in a selected position in the bore14. Thus, the orthopedic locking screw12can be secured through the orthopedic implant16. The pitch of the deformable thread32of the casing26is, in the present arrangement, substantially equal to the pitch of the internal thread70of the bore14of the orthopedic implant16. In this case an axial press-fit pressure is caused when the forward external thread34comes into contact with the bone on the opposite side of the orthopedic implant16by drawing the shaft18and the casing26through the implant bore14. Alternatively, the pitch of the deformable thread32of the casing26can be slightly different from the pitch of the internal thread70of the bore14of the orthopedic implant16, thereby achieving, alternately or in addition, an axial press-fit pressure during screwing in of the orthopedic locking screw12into implant bore14. In this case, the pitch of the deformable thread32of the casing26may also be larger or smaller than the pitch of the internal thread70of the bore14of the orthopedic implant16. In the present embodiment, the diameter of the deformable thread32of the casing26is substantially equal to the diameter of the internal thread70of the bore14of the orthopedic implant16. The minor diameter Dmin of the deformable thread32is constant along the length of the thread. However, in other arrangements, the minor diameter Dmin may vary along the length, such as by increasing continuously or discontinuously from the first end28toward the second end30. In the arrangement ofFIG.6, the deformable thread32is sized such that the minor diameter Dmin is substantially equal to the minor diameter of the internal thread70. In order to optionally achieve a radial press-fit pressure, at least one outside cross-sectional width of the casing26, such as either the major diameter Dmaj or the minor diameter Dmin, may be sized to be larger than a corresponding smallest inside cross-sectional opening of the bore14, such as the corresponding minor diameter or the major diameter of the internal thread70. Thus, the major diameter Dmaj of the deformable thread32may be larger than the major diameter of the internal thread70. Additionally or alternatively, the minor diameter Dmin of the deformable thread32may be larger than the minor diameter of the internal thread70to create a radial press-fit pressure. However, other embodiments may include only one or the other feature or both features so as to form only a radial press-fit pressure or an axial press-fit pressure or both press-fit pressures if desired. Turning now toFIGS.7and8, both drawings show side views of an orthopedic fastening system embodiment and a method of securing an orthopedic screw12in a bore14of an orthopedic implant16(in the form of an intramedullary nail). As shown, the orthopedic locking screw12will operably be engaged with, such as in and/or through, the bore14. The intramedullary nail16includes at least one, and optionally several bores14. The bores14may be threaded bores and/or include any and/or all of the features of the bore14previously described herein. The orthopedic locking screw12is the same as described previously. The descriptions thereof are not repeated here for brevity, but reference is made to the previous explanations in view of the following additional or alternative arrangements. Remaining aspects of this system are substantially similar as corresponding portions previously described herein and are not repeated here for the sake of brevity. Alternatively or in addition, other orthopedic locking screw embodiments as described above or hereinafter could be used with the orthopedic systems shown inFIG.7or8. The methods described herein are not limited to the orthopedic locking screw12and the orthopedic implant16. Rather, the methods may be used to engage any one of the orthopedic screws to any one of the bores disposed in any one of the orthopedic implants and/or the intramedullary nail disclosed herein or otherwise. With reference toFIG.7, a first method of securing an orthopedic locking screw to a bore will be described. Thus, the following description, while focused mainly on the arrangement shown inFIG.7for exemplary reasons, also refers to other arrangements. It is to be understood that this method is not limited to the exact description of these particular arrangements, but can be applied to any arrangement in a manner that would be understood by the ordinarily skilled person. In the case according toFIG.7, the forward external thread34of orthopedic locking screw12has a pitch that is different (e.g., larger) from the pitch of the deformable thread32of the casing26. For example, the pitch of the forward external thread34is about 1.75 and the pitch of the deformable thread32is about 1.25. Generally, the pitch difference could range between 0.1 and 1.0. Further, the pitch of the deformable thread32is substantially equal to the pitch of the internal thread70of the implant bore14, but it could also be different. The intramedullary nail16is inserted in bone80comprising marrow76. The marrow76is circumferentially encased by cortex as illustrated by a first cortex portion78(on the left inFIGS.7and8) and a second cortex portion80(on the right inFIGS.7and8). In a further step, the first end20of the shaft18is inserted through the first cortex portion78and marrow76into the bore14of the orthopedic implant16. The shaft18is advanced into the bore14in any sufficient manner, such that the forward external thread34is advanced through the bore14, for example by driving. When the deformable thread32of the casing26comes into engagement the internal thread70of the bore14, the shaft18may be rotated, for example with a rotational drive tool engaged with the drive member24, to advance the shaft18and the casing26into and/or through the bore14. In this case, the deformable thread32operably (threadably) engages the bore14so as to form a mechanical interfit with the internal thread70of the bore14as shown in the upper enlarged view ofFIG.7. The shaft18is advanced through the bore14in any manner, as appropriate. When the forward external thread34comes into engagement with bone on the opposite side of the orthopedic implant16, i.e., with the second cortex portion80, the drive member24is rotated further, which rotates the shaft18and the casing26, so as to operably (threadably) engage the forward external thread34with bone. Due to the fact that the pitch of the forward external thread34is different (e.g., larger) from the pitch of the deformable thread32, the forward external thread34operates to advance (e.g., by pulling) the shaft18and the casing26forward through the bore14of the orthopedic implant16. Thereby, the bore14and, specifically, its internal thread70deforms the casing26and its deformable thread32, respectively, axially and/or radially. The deformation of the deformable thread32results in a press-fit of the casing26against the bore14in an axial pressure direction and/or a radial pressure direction as shown in the lower enlarged view ofFIG.7. The press-fit pressure may increase as the casing26advances through the bore14. For example, where the deformable thread32has a variable pitch, increased axial press-fit pressure may be developed as the casing26advances through the bore14. Where the deformable thread has an increasing outside diameter, such as an increasing minor diameter and/or major diameter, increased radial press-fit pressure may be developed as the casing26advances through the bore14. The outer surface of the casing26could also be cylindrical and any deformable thread32could have a constant pitch along the length of the casing, in which case the press-fit pressure may remain substantially constant as the casing26advances through the bore14. Additionally, the rear external thread36may also operate to advance (e.g., by pushing) the shaft18and the casing26through the bore14by engaging with the bone on the insertion side of the orthopedic implant16, i.e., with the first cortex portion78. Now turning toFIG.8, the drawing shows another orthopedic locking system embodiment and a second method of securing an orthopedic locking screw12to a bore14of an orthopedic implant16. The difference between the orthopedic locking system and method ofFIG.8and that described with reference toFIG.7is that the pitch of the deformable thread32of orthopedic locking screw12is different (e.g., slightly larger) from the pitch of the internal thread70of the implant bore14. For example, the pitch of the deformable thread32is about 1.3 and the pitch of internal thread70of the implant bore14is about 1.25. Generally, the pitch difference could range between 0.01 and 0.3. The forward external thread34of orthopedic locking screw12can still have a pitch that is different (e.g., larger) from the pitch of the deformable thread32of the casing26. Remaining aspects of the system and method are substantially similar as previously described herein and is not repeated here for the sake of brevity. In the particular system and method according toFIG.8, the pitch of the deformable thread32is slightly larger than the pitch of the internal thread70of the implant bore14. Thus, in the step where the shaft18is rotated, for example with a rotational drive tool engaged with the drive member24, to advance the shaft18and the casing26into and/or through the bore14and the deformable thread32operably engages the internal thread70of the bore14, an axial press-fit pressure is achieved due to the different thread pitches of the deformable thread32and the internal thread70. In this case, the deformable thread32and/or the internal thread70itself operates to advance (e.g., by pulling) the shaft18and the casing26forward through the bore14of the orthopedic implant16during screwing in of the orthopedic locking screw12into implant bore14. Thereby, the bore14and its internal thread70(slightly) deforms the casing26and its deformable thread32, respectively, axially, thereby developing an axial press-fit of the casing26against the bore14in an axial pressure direction as shown in the upper enlarged view ofFIG.8. Once the forward external thread34comes into engagement with bone on the opposite side of the orthopedic implant16, i.e., with the second cortex portion80, the drive member24is rotated further, which rotates the shaft18and the casing26, so as to operably (threadably) engage the forward external thread34with bone. If the pitch of the forward external thread34is also different (e.g., larger) from the pitch of the deformable thread32, the forward external thread34operates to advance (e.g., by pulling) the shaft18and the casing26forward through the bore14of the orthopedic implant16. Thereby, the bore14and its internal thread70further deforms the casing26and its deformable thread32, respectively, axially and/or radially, thereby increasing the press-fit of the casing26against the bore14in an axial pressure direction and/or a radial pressure direction as shown in the lower enlarged view ofFIG.8. An aspect of the second system and method as described with reference toFIG.8is that once the forward external thread34engages the bone80and is operated to draw the shaft18and the casing26forward through the implant bore14, the deformable thread32cannot engage with the internal thread70of the implant bore14again. Next, a further method embodiment of securing an orthopedic screw12in a bore14of an orthopedic implant16is described with reference toFIGS.7and8. This embodiment can be combined with the method embodiments described above. In a first step, a bore82having a first diameter BD1is drilled into bone, e.g., into the first and second cortex portions78,80. BD1may range between 3 mm and 6 mm (e.g., between 3.5 mm and 5 mm, such as 4.2 mm). Then, at least a part of the bore82(e.g., the bore portion in the first cortex portion78) is widened by drilling with a second diameter BD2. BD may range between 4 mm and 7 mm (e.g., between 4.5 mm and 6 mm, such as 5.3 mm). The orthopedic implant16can be inserted in the marrow cavity76of bone before or after the above bone drilling steps. If the intramedullary nail16is inserted before drilling the first bore through bone, the drilling operation may be performed through the implant bore14of the intramedullary nail16. Then an orthopedic locking screw12as generally described above or hereinafter is provided. As explained above, the orthopedic locking screw12includes the shaft18extending axially between the first end20and the second end22, the drive member24disposed at the second end22, and the casing26secured to and rotationally fixed around the outer surface of the shaft18, wherein the casing26is formed of a (e.g., plastically) deformable material. The casing26has an outer cross-sectional width W1that is larger than a smallest inside cross-sectional width ND of the bore14of the orthopedic implant16. The first end20of the shaft18has an outer cross-sectional width W2that is smaller than the smallest inside cross-sectional width ND of the bore14of the orthopedic implant16but larger than the first diameter BD1of the bore82in the bone80. The system and locking screw may have further aspects substantially corresponding to portions previously described herein and is not repeated here for the sake of brevity. The first end20of the shaft18is inserted into the bore14of the orthopedic implant18. Then, the casing26comes into engagement with the bore14of the orthopedic implant18. By rotating the drive member24, the shaft18and the casing24are rotated so as to operably (e.g., threadably) engage the casing26with the bore14of the orthopedic implant16, thereby achieving an advance of the orthopedic locking screw12through the bore14of the orthopedic implant16. When the first end20of the shaft18comes into engagement with the bore82having the first diameter BD1in the bone80on the opposite side of the orthopedic implant16, the drive member24is rotated further to rotate the shaft18and the casing26so as to operably (e.g., threadably) engage the first end20of the shaft18with bone80, thereby advancing, e.g., pulling, the shaft18and the casing24through the bore14of the orthopedic implant16and achieving a deformable press-fit of the casing26against the bore14of the orthopedic implant16. Specifically, upon the operable engagement of the forward external thread34with the second cortex portion82, the different thread pitches result in a deformation of the deformable thread32of the casing26against the orthopedic implant16as the shaft18and the casing26are pulled through the bore14, thereby achieving the deformation of the deformable thread32of the casing26against the orthopedic implant16. An aspect of the third method embodiment as described above with reference toFIGS.7and8is the fact that the second diameter BD2of the “input” side opening of the cortex exceeds the first diameter BD1of the “output” side opening of the cortex. The increased second diameter BD2permits an easier advance of the casing26through the cortex. Specifically, damaging of the “input” side cortex and/or the casing26upon the shaft18being moved through the “input” side opening of the cortex can be reduced or even prevented. At the same time the forward external thread34can operably engage the “output” side opening. The above described methods and steps thereof can be individual combined with each other or extended with further steps or procedures as desired. In similar manner, the methods described can provide different locking screw embodiments and/or orthopedic implant embodiments as desired. When the orthopedic locking screw12is disposed in a selected position, the press-fit pressure between the casing26and the internal surface of the bore14prevents or reduces undesired rotational movement and/or lateral movement and/or axial movement of the orthopedic locking screw12relative to the bore14, and optionally also to the orthopedic implant16. The orthopedic locking screws of the present disclosure provide in some circumstances a tighter fit with the bore of, for example, an orthopedic implant, such as an intramedullary nail or a plate, or a bone, than has been heretofore achievable with a single orthopedic screw. As a result, undesired movement and shifting between the connected bone portions and/or the orthopedic implant may be reduced, thereby improving the healing process of the bone. In addition, the improved locking capability of the orthopedic locking screws may allow the number of locking elements needed in an orthopedic fastening system to be decreased. Other technical advantages and/or usefulness are also possible. The features described in relation to the exemplary arrangements shown in the drawings can be readily combined to result in different embodiments, as suggested previously above. It is apparent, therefore, that the present disclosure may be varied in many ways. Such variations are not to be regarded as a departure from the scope of the invention, and all modifications within the scope of the appended claims are intended to be expressly included therein. Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.

11857228

DETAILED DESCRIPTION As used herein, when referring to the femur or the intramedullary nail when implanted into the medullary canal of a patient, the term “proximal” means closer to the heart and the term “distal” means more distant from the heart. The term “anterior” means towards the front part of the body or the face and the term “posterior” means towards the back of the body. The term “medial” means toward the midline of the body and the term “lateral” means away from the midline of the body. When referring to the neck screw, the term “rear” means closer to the user, whereas the term “front” means further from the user. Throughout this description, a fracture refers to a femoral neck fracture, however, the devices described hereinafter can be used to fixate associated fractures of the femoral shaft as well as factures in other long bones, for example, the tibia or the humorous, whether the fracture be naturally occurring or surgeon-induced. FIG.1illustrates a femur10and its six anatomical regions: a diaphysis or midshaft12, proximal metaphysis14, distal metaphysis16, proximal epiphysis or head18, distal epiphysis20, and a femoral neck22. The femur10includes a hard cortex24and a medullary cavity26. The medullary cavity26includes a medullary canal28which runs through the center of shaft12, the proximal and distal metaphyseal areas30and32, and the proximal and distal epiphyseal areas34and36. FIG.2is an anterior-posterior view of a proximal portion of femur10having a fracture38extending along femoral neck22. Fracture38separates the proximal femur into a first bone portion40adjacent the proximal metaphysis14and a second bone portion42adjacent the proximal epiphysis or head18. Fracture38is an exemplary illustration of an unstable, extra-articular fracture, i.e., the fracture is located outside of a joint. This type of fracture, if not treated, can lead to long-term complications including comminution (i.e., pulverization of the bone), which may result in shortening of femoral neck22and severe pain. Referring toFIG.3, a known intramedullary intertrochanteric fracture fixation device100is shown for compressing first and second bone portions, and for maintaining rotationally stability between the first and second bone portions during healing of fracture38. Intramedullary intertrochanteric fracture fixation device100generally includes an intramedullary nail102having an angulated opening104extending through the nail in the lateral to medial direction, a neck screw106that is insertable through the angulated opening for compressing the fractured bone portions together and a set screw126for rotationally stabilizing the neck screw within the angulated opening. Referring toFIG.4, intramedullary nail102includes a rod-shaped body having a proximal portion108, a distal portion110and an intermediate portion112located between and connecting the proximal and distal portions. The rod-shaped body of intramedullary nail102is anatomically shaped to allow the intramedullary nail to be inserted into the medullary canal28of femur10(shown inFIG.1). For this reason, intermediate portion112is bent and tapered in the proximal to distal direction. The rod-shaped body of intramedullary nail102is cannulated and defines a channel114that is configured to receive a surgical wire (not shown), such as a K-wire wire, for guiding the intramedullary nail into a proper position within the medullary canal28of the femur10. Intramedullary nail102has a substantially circular cross-section over its entire length such that proximal portion108and distal portion110are substantially cylindrical. The proximal portion108of intramedullary nail102has a diameter sufficient to accommodate angulated bore104. The distal portion110of intramedullary nail102has a diameter that is smaller than the diameter of proximal portion108, and that is anatomically shaped to the medullary canal28of femur10to facilitate the insertion of the distal portion of the intramedullary nail into the medullary canal of the femur. For the same reason, the distal portion110of intramedullary nail102has a conical tip116at its distal end. The distal portion110of intramedullary nail102also defines an aperture118configured to receive a bone fastener such as a locking screw for fastening the intramedullary nail to the shaft12of femur10. As shown inFIG.5, the proximal portion108of intramedullary nail102has an axial bore122that extends along a longitudinal axis L of the proximal portion and between the proximal end of the nail and angulated opening104. Axial bore122defines a compartment120in the proximal portion108of intramedullary nail102. Compartment120may include internal threading (not shown) configured to mate with corresponding threading provided on set screw126(shown inFIG.3). Angulated opening104defines a bore axis124that is transversely angled with respect to the longitudinal axis L of proximal portion108such that the bore axis of the angulated opening has an oblique extension relative to an axial extension of the proximal portion. In other words, bore axis124of angulated opening104is oriented obliquely with respect to the longitudinal axis L of the proximal portion108. Thus, the bore axis124of angulated opening104is inclined at an angle α with respect to the longitudinal axis L of the proximal portion108. Angle α, for example, may be between approximately 90° and approximately 140°. Returning toFIG.3, neck screw106extends through angulated opening104in a lateral to medial direction. As will be explained in more detail below, neck screw106is coupled to intramedullary nail102, via set screw126, in a manner that prevents the neck screw from rotating in angulated opening104and that allows the neck screw to limitedly slide along the bore axis124to account for load shifting. Neck screw106may be a lag screw extending along a length defined between a rear end128and a front end130. The rear end128of neck screw106includes a recess132, for example, a hexalobular internal driving feature for receiving a tool tip such as a screw driver or a wrench. The front portion adjacent the front end130of neck screw106includes a thread134, such as a coarse thread, for anchoring the neck screw into intertrochanteric bone. Neck screw106further includes grooves136defined in the peripheral surface of the neck screw. Grooves136extending in a direction generally parallel to the longitudinal axis of neck screw106. For example, neck screw106may include four grooves136circumferentially spaced about the peripheral surface of the neck screw at intervals of 90°. Each groove136defines a ramp having a shallow end and a deep end. The rising ramp extends from the rear portion of neck screw106toward the front portion of the neck screw. Because the longitudinal axis of neck screw106is substantially coaxial with the bore axis124of angulated opening104, the neck screw is configured to transfer loads placed on the femoral head to the intramedullary nail102, and at the same time, bridge the fracture38and compress bone portions40,42together. Set screw126includes an engagement member138and a drive member140connected to the engagement member. The drive member140of set screw126includes an external thread configured to threadably mate with corresponding internal threading provided in axial bore122and/or compartment120. The drive member140of set screw126defines a recess142, such as a hexalobular internal driving feature for receiving a tool (e.g., a screw driver) and selectively advancing the set screw (the combination of the driving member and the engagement member which are connected together) within the axial bore122of proximal portion108. For example, using the driving tool, set screw126may be advanced distally within the axial bore122of proximal portion108by rotating the set screw in a first direction (e.g., clockwise). Set screw126may alternatively be retracted in the proximal direction within the axial bore122by rotating the set screw in a second direction opposite to the first direction (e.g., counterclockwise). The engagement member138of set screw126may be a cylindrical bolt, pin or protrusion configured to be positioned within the grooves136of neck screw106. When set screw126is axially advanced to a position in which groove136receives engagement member138, rotational movement of the neck screw within the angulated opening104of intramedullary nail102is prevented. When engagement member138is initially advanced in the distal direction and into groove136, the engagement member exerts little to no force on neck screw106. While the low force is sufficient in preventing neck screw106from rotating, the low force will permit movement of the neck screw along the axis124of angulated opening104relative to intramedullary nail102. The sliding or axial movement of neck screw106will cause a change in force (typically an increase) due to the depth profile of the lateral and medial ramps of grooves136. If the surgeon desires to limit axial sliding of neck screw106based upon specific consideration of a particular surgery, the surgeon may turn driving member140clockwise and tighten set screw126against neck screw106to increase the force and reduce or eliminate axial sliding of the neck screw. Alternatively, should the surgeon desire to increase axial sliding of neck screw106, the surgeon may loosen set screw126. The present invention provides an intramedullary intertrochanteric fracture fixation device and various set screw assemblies for use with the fixation device. Each one of the set screw assemblies described hereinafter is cannulated and thus overcomes the drawbacks associated with set screw126, namely the difficulties associated with intraoperative assembly. Because the set screw assemblies of the present invention are cannulated, the set screw assemblies can be pre-operatively assembled within the intramedullary nail and configured to receive a guidewire while disposed within the nail. That is, during operation, a surgeon may insert a guidewire through the cannula of the set screw assembly and guide the nail into position within the medullary canal of the patient. As used herein, the term “pre-operatively assembled” means that the set screw is assembled within the nail by the manufacturer before the fixation device is shipped, or alternatively, that the set screw assembly is assembled within the nail by a user before the nail is implanted into the medullary canal of a patient. Each one of the set screw assemblies set forth below may be used with an intramedullary nail that is similar to intramedullary nail102and a neck screw that is similar to neck screw106. Thus, specific features of the intramedullary nails and neck screws of the present invention are not described in detail in each embodiment unless the features are emphasized or unless the features are different than the features previously described with respect to intramedullary nail102and neck screw106. Instead, when like features are mentioned, the features are renumbered with sequential100series numerals. For example, in describing the various embodiments of the set screw assemblies, the intramedullary nail will be referenced as intramedullary nail202,302,402. Similarly, the neck screw will be referenced as neck screw206,306,406. FIG.6Aillustrates an intramedullary intertrochanteric fracture fixation device200in accordance with an embodiment of the present invention. Fixation device200includes an intramedullary nail202having an angulated opening204extending through the nail in the lateral to medial direction, a neck screw206insertable through the angulated opening and a set screw assembly244for securing the neck screw to the nail. When implanted into the femur10of a patient, fixation device200is adapted to compress first bone portion40and second bone portion42together, and prevent postoperative relative rotation of the first and second bone portions during healing of fracture38. FIG.6Bis a cross section view of set screw assembly244pre-operatively assembled within a proximal portion208of intramedullary nail202. Intramedullary nail202defines an axial bore222that extends along a longitudinal axis of the nail, and between the proximal end of the nail and angulated opening204. Axial bore222includes internal threading246and a compartment220located between the internal threading and angulated opening204. Compartment220is adapted to receive and retain set screw assembly244and is defined by an upper ledge248for limiting proximal movement of the set screw assembly, a lower ledge250for limiting distal movement of the set screw assembly and a sidewall252. Compartment220includes an upper portion254located adjacent to upper ledge248, a lower portion256located adjacent to lower ledge250and an intermediate portion258located between the upper and lower portions. Intermediate portion258may taper inwardly from upper portion254to lower portion256such that the upper portion of the compartment has a greater diameter than the lower portion of the compartment. With specific reference toFIG.6C, a longitudinally extending slot260is defined in the sidewall252of compartment220. In some embodiments, slot260may extend between lower ledge250and the intermediate portion258of compartment220. Set screw assembly244, as illustrated inFIGS.7A and7B, includes a first member262, a second member264and a third member266. Each of the first, second and third members are cannulated such that when the members are coupled together and pre-operatively assembled within intramedullary nail202, the set screw assembly244is configured to receive a guidewire as shown inFIG.6D. Referring now toFIGS.8A and8B, first member262includes a proximal portion268that is adapted to receive third member266, and a distal portion270having threading272about its external surface for threadably coupling the first and second members together. With specific reference toFIG.8B, a lumen274extends through distal portion270. Lumen274may define a hexalobular internal driving feature adapted to receive a tool tip, such as a screw driver or a hex key, for rotating first member262in a first direction and threading the first member into second member264, or alternatively, rotating the first member in a second direction and unthreading the first member from the second member. The proximal portion268of first member262includes a sidewall276and a plurality of vertically extending flanges278. The combination of the sidewall276and vertically extending flanges278circumscribe and define an internal receiving space280configured to receive third member266. An interior surface of sidewall276may include threading282. Flanges278are adapted to flex radially outward as a force is applied on an interior surface of the flange, for example, when third member266is forced into receiving space280. In one embodiment, flanges278may include thickened proximal ends for engaging the sidewall252of compartment220, and for contacting the upper stop248of the compartment. AlthoughFIGS.8A and8Billustrate the proximal portion268of first member262as having two diametrically opposed flanges278, it will be understood that the first member may alternatively have one flange, or any number of flanges greater than two. An exterior surface of the proximal portion268of first member262may include a taper at a location adjacent to the distal portion270of the first member that corresponds to the taper of the intermediate portion258of compartment220. In one embodiment, the exterior surface of the sidewall276of proximal portion268may include a threading (not shown) for threadably mating set screw assembly244to the internal threading246provided within the proximal portion208of intramedullary nail202. With reference toFIGS.9A and9B, second member264includes a cannulated body284having a proximal end286and a distal end288. An internal surface of cannulated body284includes a threading290that corresponds to threading272provided on the distal portion270of first member262such that the distal portion of the first member can be threadably secured within the body of the second number. The proximal end286of second member264includes a laterally extending flange292. As illustrated, the laterally extending flange292may have arcuate shape that is sized to be positioned within longitudinal slot260for preventing rotational movement of the second member within compartment220, and a bottom surface for contacting lower ledge250for limiting distal movement of the second member. As shown inFIGS.9A and9B, one or more extensions294may protrude from the distal end288of second member264. Extension294is sized and shaped to extend into the angulated opening204and into one of the grooves236of neck screw206when set screw assembly244is disposed within intramedullary nail202. The distal end288of second member264may be traversely angled relative to the proximal end286of the second member such that when set screw assembly244is disposed within compartment220, only the extension294protrudes into angulated opening204. Referring toFIG.10, third member266is cannulated and is generally frustoconical in shape. That is, the proximal end of third member266has a greater diameter than the distal end of the third member. In one embodiment, as shown inFIG.10, an exterior surface of third member266includes a threading296that corresponds to the threading282provided on the interior sidewall276of first member262such that the third member may be threaded into the receiving cavity280of the first member. A plurality of recesses298may be circumferentially disposed about an interior sidewall of third member266for receiving the tip of a driving tool and rotating the third member to thread the third member into the receiving cavity280of first member262, or alternatively, rotating the third member in an opposite direction to retract the third member from the receiving cavity of the first member. Alternate third member266′, shown inFIG.11, does not include external threading. Instead, the external surface of third member266′ is flat such that the alternate third member may slide into the receiving cavity of the first member. It will be appreciated that in the alternate embodiment, the inner sidewall of the receiving cavity need not include threading. Moreover, alternate third member266′ may include one or more recesses (not shown) configured to receive a driving tool for pushing or otherwise driving the alternate third member into the receiving cavity of the first member. Use of intramedullary intertrochanteric fracture fixation device200for healing fracture38will now be described with reference toFIGS.6A,6B,6D,7A and7B. To assemble set screw assembly244, the distal portion270of first member262is threaded into second member264until the proximal portion268of the first member contacts the upper surface of the lateral flange292of the second member. The third member266is then partially threaded or otherwise inserted into the receiving cavity280of first member262. At this stage, as illustrated inFIG.7A, the proximal end of the third member remains outside of the receiving cavity280of first member262such that the vertical flanges278of the first member are in an unbiased condition (e.g., substantially vertically oriented). Assembled set screw assembly244may then be pre-operatively assembled within the proximal portion208of intramedullary nail202such that the set screw assembly is engaged with the internal threading246of the intramedullary nail or otherwise positioned proximal to compartment220. As shown inFIG.6D, a surgeon may then insert a guidewire through the cannulated set screw assembly244and use the guidewire in a conventional manner to advance the intramedullary nail202into position within the medullary canal28of the patient. After intramedullary nail202has been positioned within the medullary canal28of femur10, the surgeon may remove the guidewire and insert neck screw206through the angulated opening204of the intramedullary nail in order to compress the fractured bone portions together. Set screw assembly244may then be threaded or otherwise pushed into compartment220as shown inFIG.6B(neck screw not shown for clarity) and rotated until lateral flange292is positioned within slot260. Once slot260has received lateral flange292, second member264will be prevented from rotating within compartment220. Set screw assembly244may then be further driven in the distal direction along longitudinal axis L until the underside of lateral flange292engages the lower stop250of compartment220and the extension294of second member264extends into the groove136of neck screw206, thereby preventing the neck screw from rotating about bore axis124and relative to the extensions of the set screw assembly. Neck screw206is thus effectively prevented from rotating within angulated opening204. After the surgeon has confirmed that neck screw206is appropriately positioned within the intertrochanteric bone, the surgeon may then insert a driving tool into the recesses298of third member266, or into the recesses of third member266′, to drive the third member into the receiving cavity280of first member262. As third member266, or third member266′, is driven into the receiving cavity280of first member262, the frustoconical shape of the third member forces the vertical flanges278of the first member to bias outwardly and toward the sidewall252of compartment220. The biased flanges278of first member262will prevent set screw assembly244from backing out of compartment220even if a proximal force is applied to the set screw assembly. For example, due to the angulation of angulated opening204and the ramped surfaces of the grooves236, axial movement of neck screw206results in a proximal force being applied to neck screw206and in some instances proximal movement of set screw assembly244. However, the proximal movement of set screw assembly244will be limited by engagement between the vertical flanges278of first member262and the upper ledge248of compartment220as is further explained below. The surgeon may optionally choose to limit the relative axial movement between neck screw206and intramedullary nail202. In order to set this limit, the surgeon inserts a driving tool such as a hex key into the lumen274of the distal portion270of first member262and rotates the first member until the desired limit has been reached. Because the lateral flange292of second member264is positioned within slot260and the second member is prevented from rotating within compartment220, rotation of the first member262will result in the threading or the unthreading of the first member from the second member and relative axial movement between the first and second members. Consequently, if the surgeon desires to decrease the relative axial movement between neck screw206and intramedullary nail202, the surgeon may rotate the driving tool in a first direction (e.g., counter clockwise) causing the distal portion270of the first member262to unthread from the body284of second member264such that the first member moves in the proximal direction relative to the second member. Proximal movement of first member262relative to second member264will increase the overall length of set screw assembly244and decrease the distance between the proximal end of the vertical flanges278of the first member and the upper stop248of compartment220. As a result, the permitted movement of neck screw206in an axial direction will be reduced, as even slight movement of the neck screw will result in proximal movement of set screw assembly244and engagement between the proximal end of the vertical flanges278and the upper stop248of compartment220. Once the vertical flanges278engage the upper stop248of compartment220, further proximal movement of set screw assembly244will be prevented and the set screw assembly will apply a counter-force on neck screw206, thereby prohibiting further axial movement of the neck screw. Accordingly, if the surgeon desires to prevent all axial sliding of neck screw206, the surgeon may intraoperatively rotate first member262in the counter clockwise direction until the proximal end of the vertical flanges278engage the upper stop248of compartment220. In contrast, if the surgeon desires to increase the amount of relative axial movement between neck screw206and intramedullary nail202, the surgeon may rotate the driving tool in a second direction (e.g., clockwise). Clockwise rotation of first member262relative to the second member264will result in the distal portion270of the first member being threaded into the body284of the second member, thereby increasing the distance between the proximal end of the vertical flanges and the upper stop248of compartment220. As a result, neck screw206will be permitted to slide relatively further in the axial direction before the vertical flanges278of first member262contact the upper stop248of compartment220. FIGS.12-13Billustrate a proximal portion of an intramedullary intertrochanteric fracture fixation device300in accordance with another embodiment of the invention. Fixation device300includes an intramedullary nail302, a neck screw (not shown) and a set screw assembly344. AlthoughFIG.12does not illustrate a neck screw, it will be understood that fixation device300includes a neck screw similar to neck screw206. Set screw assembly344may be pre-operatively assembled within intramedullary nail302as shown inFIG.12. Intramedullary nail302is substantially the same as previously described intramedullary nail202. For this reason, intramedullary nail302is not described hereinafter in detail. Instead, where like features are mentioned, these features are referenced with corresponding300series numerals. Referring toFIGS.13A and13B, set screw assembly344includes a cannulated first member362and a cannulated second member364such that when the first and second members are coupled together and pre-operatively assembled within intramedullary nail302, the set screw assembly is configured to receive a guidewire (not shown). Second member364is substantially the same as previously described second member264(shown inFIGS.9A and9B). Accordingly, second member364is not described again in detail. Instead, where like features are recited, the like features are referenced using corresponding300series numerals. First member362includes a proximal portion368, a distal portion370and a ring-like intermediate portion366disposed between the proximal and distal portions. Distal portion370includes a threading372provided about an exterior surface of the distal portion for threadably coupling the first and second members together. Referring back toFIG.12, distal portion370defines a lumen374adapted to receive a tool tip, such as a screw driver or a hex key, for rotating first member362in a first direction and threading the first member into second member364, or alternatively, rotating the first member in a second direction and unthreading the first member from the second member. The proximal portion368of first member362, as illustrated inFIGS.13A and13B, includes a plurality of flexible flanges378. Each one of the flanges378has an attached end376connected to the intermediate portion366, a free end382opposite to the attached end and one or more step-like notches396provided between the attached end and the free end. The attached ends376of flanges378are connected to the intermediate portion366at a location adjacent to the circumferential edge of the intermediate portion such that the plurality of flanges circumscribes and defines an internal cavity380. AlthoughFIGS.13A and13Billustrate the proximal portion368of first member362as having four flanges378, it will be understood that the first member may alternatively have two or three flanges, or any number of flanges greater than four. Each one of the flanges378are spaced apart from adjacent flanges such that a gap398is formed therebetween allowing the flanges378flex radially inward as a force is applied to the exterior surface of the flanges. The step-like notches396are sized and configured to receive the upper ledge348of compartment320. The flexible flanges378may be tapered radially outwardly from the attached end376toward the step-like notches396such that the proximal portion368of first member362is generally bulbous shaped. Use of intramedullary intertrochanteric fracture fixation device300for healing fracture38will now be described with reference toFIGS.12-13B. To assemble set screw assembly344, the distal portion370of first member362is threaded into the body384of second member364until the intermediate portion366of the first member contacts the lateral flange392of the second member. Assembled set screw assembly344may then be inserted through the proximal end of intramedullary nail302and pre-operatively positioned within the axial bore322of the nail such that the set screw assembly is engaged with the internal threading346of the intramedullary nail, or otherwise positioned proximal to compartment320. A surgeon may then insert a guidewire through the cannulated set screw assembly344and use the guidewire in a conventional manner to advance the intramedullary nail302into position within the medullary canal28of the patient. After intramedullary nail302has been positioned within the medullary canal28of femur10, the surgeon may remove the guidewire and insert a neck screw through the angulated opening304of the intramedullary nail in order to compress the fractured bone portions together. Set screw assembly344may then be driven distally into compartment320as shown inFIG.12(neck screw not shown for clarity) and rotated until the lateral flange392of second member364is positioned within the longitudinal slot360of the compartment. Once the longitudinal slot has received lateral flange392, second member364is prevented from rotating within compartment320. Set screw assembly344may then be further driven in the distal direction until the underside of the lateral flange392of second member364engages the lower stop350of compartment320and the extensions394of the second member extend into a groove of the neck screw. As a result, the neck screw is prevented from rotating within angulated opening304. As the proximal portion368of first member362is driven distally into compartment320, the inner edge of the upper ledge348contacts and applies a compression force to the outwardly tapered surface of flanges378. The compression force causes the flanges to flex radially inward toward the interior cavity380of first member362. Gaps398aid in the flexing of flanges378. Once the outwardly tapered surface of flanges378has been passed through the upper ledge348of compartment320, the flanges radially expand to their natural condition and the step-like notches396engage the upper ledge of the compartment as shown inFIG.12. The engagement between notches396and the upper ledge348of compartment320prevents set screw assembly344from backing out of the compartment even when a proximal force is applied to the set screw assembly, for example, when the neck screw slides along angulated opening304. Set screw assembly344provides the surgeon the ability to limit relative axial movement between the neck screw assembly and the intramedullary nail302. In order to intraoperatively set this limit, the surgeon may insert a driving tool such as a hex key into the lumen374of the distal portion370of first member362and rotate the first member independently and relative to second member364. For example, if the surgeon desires to decrease the relative axial movement between the neck screw and intramedullary nail302, the surgeon may rotate the driving tool in a first direction (e.g., counter clockwise) causing the second member364to unthread from the distal portion370of first member362, and the extensions394of the second member364to move further into the grooves of the neck screw, thus reducing the distance that the neck screw is permitted to slide. On the other hand, if the surgeon desires to increase the amount of relative axial movement between the neck screw and the intramedullary nail, the surgeon may rotate the driving tool in a second direction (e.g., clockwise) causing the extensions394of the second member364to retract away from the neck screw, thus permitting the neck screw to slide relatively further in the axial direction. FIGS.14-16illustrate a proximal portion of an intramedullary intertrochanteric fracture fixation device400in accordance with a further embodiment of the invention. Fixation device400includes an intramedullary nail402having an angulated opening404extending through the intramedullary nail in the lateral to medial direction, a neck screw406insertable through the angulated opening and a set screw assembly444for securing the neck screw to the nail. When implanted into the femur of a patient, fixation device400is adapted to compress first bone portion40and second bone portion42together, and prevent postoperative relative rotation of the first and second bone portions during healing of fracture38. FIG.14is a cross section view of set screw assembly444pre-operatively assembled within a proximal portion408of intramedullary nail402. Intramedullary nail402defines an axial bore422extending along a longitudinal axis of the nail, and between the proximal end of the nail and angulated opening404. Axial bore422includes internal threading446and a compartment420located between the internal threading and angulated opening404. Compartment420is adapted to receive and retain set screw assembly444and is defined by an upper notch447having an upper ledge448and a lower ledge450, a lower longitudinal slot460and a sidewall452. Lower slot460is defined in the sidewall452of compartment420and may extend from a location adjacent angulated opening404toward the lower ledge450of upper notch447. Referring toFIG.15A, set screw assembly444includes a first member462, a second member464and a split ring466. First member462and second member464are cannulated such that when the first and second members are coupled to split ring466and pre-operatively assembled within fixation device400, the set screw assembly444is configured to receive a guidewire. Referring now toFIG.15B, first member462is a fastening member having a head or proximal portion468, a threaded shaft or distal portion470and a neck476disposed between the head and the shaft. Shaft470includes threading472about its external surface for threadably coupling the first member462and the second member464together. Shaft470may optionally define one or more slits extending in a longitudinal direction along the shaft. First member462also defines a lumen274that extends completely through the first member from the proximal end of head468to the distal end of shaft470. Lumen474forms an internal driving feature, for example, a hexalobular driving feature adapted to receive a tool tip for rotating the first member in a first direction and threading the first member into second member464, or alternatively, rotating the first member in a second direction and unthreading the first member from the second member. Second member464is substantially the same as second member264and second member364except as discussed below Unlike second members264,364, second member464does not have a lateral flange extending from its proximal end. Instead, the proximal end486of second member464defines a rim for receiving split ring466. Furthermore, second member464includes a protrusion492that extends in a lateral direction from the body284of the second member and preferably from a location adjacent to the distal end488of the second member. The protrusion492is sized and configured to be received in the slot460of compartment420. Split ring266may be formed from a compliant material such that the split ring is capable of radial compression and radial expansion. Split ring266is sized and shaped to be wedged between the neck476of first member462and the rim of the second member464. Furthermore, split ring266may define a notch496that extends about the circumference of the split ring. The notch496of split ring466is complimentarily sized and shaped to the rim of second member464such that the split ring is designed to be seated on the rim of the second member. Use of intramedullary intertrochanteric fracture fixation device400will now be described with reference toFIGS.14-16. To assemble set screw assembly444, a user may first couple split ring466to second member464by positioning the notch496of the split ring on the rim of the second member. The user may then thread the shaft470of first member462into the threading490of second member464coupling the first and second members together and sandwiching the split ring466between the neck476of the first member and the rim of the second member as shown inFIG.15A. Assembled set screw assembly444may then be inserted through the angulated opening404of intramedullary nail402, fed into compartment420and moved in the distal to proximal direction until the neck476of first member462engages the upper ledge448of the compartment such that the neck is positioned within upper notch474. If necessary, set screw assembly444may be rotated, before, during or after the set screw assembly is positioned within compartment420to ensure that the protrusion492of second member464is positioned within the slot460of the compartment. With set screw assembly444pre-operatively assembled within the proximal portion408of intramedullary nail402, the surgeon may insert a guidewire through the cannulated set screw assembly and advance the intramedullary nail402into position within the medullary canal28of the patient. After intramedullary nail402has been positioned within the medullary canal28of femur10, the surgeon may then remove the guidewire and insert neck screw406through the angulated opening404of the intramedullary nail, as shown inFIG.14, in order to compress the fractured bone portions together. First member462may then be independently rotated relative to second member464, allowing the surgeon to control the distance that intramedullary nail202is permitted to slide. Rotation of first member464causes the first member to rotate independently of second member464(which is rotationally stabilized by the engagement between the protrusion492of second member464the slot460of compartment420) and results in the second member unthreading from the distal portion470of the first member, and separation of the first and second members. As shown inFIG.16, distal movement of second member464will cause the extensions494of the second member to extend into the angulated opening404of intramedullary nail402and to be received within a groove436of neck screw406, thereby preventing the neck screw from rotating relative to the extensions of the set screw assembly. Neck screw406is thus prevented from rotating within angulated opening404. Furthermore, as second member464moves in the distal direction and separates from first member462, the first and second members will disengage from split ring466and the ring will radially expand into the upper notch447of compartment420. It will be appreciated that the radial expansion of ring466aides in limiting the axial sliding of neck screw406. For example, prior to the radial expansion of split ring466, the neck467of first member462is permitted to slide axially within the upper notch447. However, after the split ring466expands, proximal movement of set screw assembly444is limited by the engagement between the neck476of first member462and the upper ledge448of compartment420, while distal movement of the set screw assembly is limited by engagement between the split ring and the lower ledge450of the compartment. As a result, axial movement of set screw assembly444is reduced, which in turn, reduces the permitted axial movement of neck screw406. The surgeon may then optionally fine tune the desired axial movement of neck screw406based upon individual considerations of a particular surgery. For example, if the surgeon desires to decrease the relative axial movement between neck screw406and intramedullary nail402, the surgeon may insert a driving tool such as a hex key into the lumen474of first member462and rotate the first member in a first direction (e.g., counter clockwise) resulting in separation between the first and second members and an overall lengthening of set screw assembly444. The lengthening of set screw assembly444results in the neck476of the first member pressing against the upper ledge448of compartment420and applying a counter-force to neck screw406via the extensions494of the second member. Conversely, if the surgeon desires to increase the amount of relative axial movement between neck screw406and intramedullary nail402, the surgeon may rotate the driving tool in a second direction (e.g., clockwise). Clockwise rotation of first member462relative to the second member464will result in the distal portion470of the first member being threaded into the body484of the second member, thereby increasing the distance between the extensions494of the second member and the surface of the groove436of neck screw406. Neck screw406will thus be permitted to slide relatively further in the axial direction. Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.

11857229

DETAILED DESCRIPTION The aspects of the present disclosure and the various features and advantageous details thereof are explained more fully with reference to the non-limiting aspects and examples that are described and/or illustrated in the accompanying drawings and detailed in the following description. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale, and features of one aspect may be employed with other aspects as the skilled artisan would recognize, even if not explicitly stated herein. Descriptions of well-known components and processing techniques may be omitted so as to not unnecessarily obscure the aspects of the present disclosure. The examples used herein are intended merely to facilitate an understanding of ways in which the present disclosure may be practiced and to further enable those of skill in the art to practice the aspects of the present disclosure. Accordingly, the examples and aspects herein should not be construed as limiting the scope of the present disclosure, which is defined solely by the appended claims and applicable law. Moreover, it is noted that like reference numerals represent similar parts throughout the several views of the drawings. Orthopedic bone plates, intramedullary nails, systems, and methods of treatment are provided. The bone plates and nails may be useful in repair of the clavicle. Although further described with reference to treatment of the clavicle, it will be appreciated that the system and devices may be adapted for use with any bones, including but not limited to, the femur, tibia, humerus, fibula, ulna, radius, bones of the foot, bones of the hand, or the like. Referring toFIGS.1-19, anterior fixation plates100a-100din accordance with various embodiments of the disclosure will be described.FIGS.1a,1b,3a,3b,4aand4billustrate anterior fixation plates100a,100bpositioned along an anterior surface of a clavicle10. Each anterior fixation plate100a,100bincludes an elongate body102extending between opposed ends101,103with an outer surface105and an inner, bone contacting surface107. Referring toFIGS.2A-2D, the anterior plates100a,100a′,100b,100b′ are anatomically contoured to fit along the curved anatomy of the anterior clavicle. The anterior plates100a,100a′,100b,100b′ are interchangeable for left-side and right-side clavicles. As the curvature of the bone varies between individuals, the anterior plates100a,100a′,100b,100b′ are offered in multiple contours, with exemplary contours illustrated inFIGS.2A-2D. Each plate100a,100a′,100b,100b′ includes a central portion104extending between end portions106,108. Referring first toFIGS.2A and2B, the contour of the plate100a,100a′ is defined by the angle α, β of the end portions106,108relative to the central portion104as well as the curvature R1, R2, R3, R4of each end portion106,108. The angle α of plate100amay range, for example, from about 20-30°, about 20-25°, about 23-25°, or about 24°. The angle β of plate100′ may range, for example, from about 30-40°, about 30-35°, about 33-35°, or about 34°. The radius R1, may range, for example, from about 100-200 mm, about 120-160 mm, or about 140 mm. The radius R2may range, for example, from about 10-100 mm, about 60-100 mm, or about 80 mm. The radius R3may range, for example, from about 50-150 mm, about 90-130 mm, or about 110 mm. The radius R4may range, for example, from about 10-100 mm, about 30-70 mm, or about 50 mm. In the illustrated embodiments, the angle α of plate100(for example 24°) is smaller than the angle β of plate100′ (for example 34°) and the radiuses R1, R2(for example 140 mm, 80 mm) are larger than the radiuses R3, R4(for example 110 mm, 50 mm). With the illustrated configurations, the plate100aofFIG.2Ais said to have a shallow configuration while the plate100a′ ofFIG.2Bis said to have a deep configuration. Referring toFIGS.2C and2D, the plates100b,100b′ have a longer length with the ends106,108extending over a greater arcuate length. Each arcuate length is defined by the arc of a respective ellipse. As in the previous embodiments, the plates100b,100b′ may have varying radiuses to achieve a shallow configuration as in plate100bor a deep configuration as in plate100b′. The plates100a,100a′,100b,100b′ may have various angles and radiuses or elliptical dimensions and are not limited to the illustrative examples. Selecting a contoured plate100a,100a′,100b,100b′ closely matching the bone's contour minimizes plate prominence and irritation under soft tissue. Referring toFIGS.3A-6, the anterior fixation plate100a,100bis further contoured in both width and cross-sectional thickness. In the illustrated embodiment, the plate100a,100bhas a largest cross-sectional thickness T1in the central portion104and then tapers to smaller cross-sectional thickness T2, T3in each end portion106,108. The thicknesses T2, T3in the end portions106,108may be the same or distinct from one another. As illustrated inFIGS.5A,5B and6, the plate100a,100bmay include additional taper109at the plate ends101,103, beyond the last hole. The additional taper109aids sub-muscular insertion of the plate for minimally-invasive procedures. The plate100a,100balso has a largest width W1in the central portion104and then narrows to smaller widths W2, W3in each end portion106,108. The widths W2, W3in the end portions106,108may be the same or distinct from one another. Referring toFIG.5A, in the plate100a, the end portion108narrows at different rates, with the portion108aclosest to the central portion104narrowing more steeply than the portion108btoward the end103, which has a more gradual narrowing. Referring toFIG.5B, in the plate100b, the end portion108narrows at a constant rate. The plate100a,100bthicknesses and widths are selected such that the plate100a,100boptimally spans a common clavicle fracture zone. Image research study of clavicle fractures is used to identify the most common fracture zones. For example, referring toFIGS.40A,40B and40D, image studies may show that a common fracture zone12occurs at a location which is about 42% of the length of the bone10. Accordingly, the plates100are configured such that the central portion104will overly the area at about 42% of the length of the bone10when the plate100is attached to the bone10.FIGS.40C and40Eillustrate instances wherein studies show a common fracture zone12at different positions along the bone10, namely, at 35% of the bone length and 50% of the bone length, respectively. Accordingly, the plates100are configured such that the central portion104will overly the area at about 35% of the length of the bone10or 50% of the length of the bone when the plate100is attached to the bone10. The length, thicknesses and width of each plate portion104,106,108are selected such that the optimal span comprises a thicker cross-sectional area and greater moment of inertia for a distance appropriate to the extent of the fracture zone. At either end of the optimal span, where strength is less essential, the plate100narrows in width and tapers lower in thickness. This narrowing and taper enables the plate100to be low-profile, minimizing prominence and irritation under soft tissue. Referring toFIGS.7-11, the plate100a,100bmay also include a rounded outer surface105and a rounded inner surface107. The rounded surfaces105,107assist in keeping plate prominence to a minimum. The inner surface107may further include cylindrical or elliptical undercuts112,114sweeping the length of the plate100. The undercuts112,114reduce the contact surface of the plate100a,100bagainst the clavicle bone10. This may reduce damage to the periosteum, preserve blood supply, reduce osteonecrosis, and speed fracture consolidation. Referring toFIGS.10and11, an exemplary undercut pattern is illustrated. The plate inner surface107has a curvature with a radius of RAand defines the bone contacting surface. The radius RAis similar to the radius of the clavicle bone surface. Each of the undercuts112,114extends the length of the plate100and has a radius RB, RC, respectively. The radiuses RB, RCmay be the same or may be different from one another. The radiuses RB, RCof the undercuts112,114are smaller than the radius containing the plate/bone contact surfaces RA. The undercuts112,114reduce plate contact with the bone surface while only minimally reducing cross-sectional strength. While two undercuts are illustrated, more or fewer undercuts, either circular or elliptical, may be utilized. Referring toFIGS.12and13, side relief cuts116extend into the body102of the plate100a,100balong the sides thereof. In the illustrated embodiments, the relief cuts116are provided in opposed pairs on each side of the body102, however, other configurations may be utilized. The relief cuts116are positioned between screw holes thereby reducing the moment of inertia between the screw holes to allow preferential bending between holes, helping to minimize deformation of the screw holes. The illustrated relief cuts116have a rounded or smooth configuration to minimize the risk of kinking or fracture. As illustrated inFIGS.1A,4A and14A, the relief cuts116in the plate100aare present near the end portions106,108of the plate100awhere contour customization by bending is the most likely to be desired, however, other configurations may be utilized. For example, in the plate100b, as illustrated inFIGS.1B,4B and14B, the relief cuts116are present in the central portion104as well as near the end portions106,108of the plate100b. Referring toFIGS.14A-19, the plates100a-100dmay be provided with various through holes, including oblong suture holes120, round K-wire holes126, dynamic compression plating (DCP) slots130, and polyaxial holes136. The oblong suture holes120are positioned along but inward of the side edges of the plate body102. The round K-wire holes126are provided at each end101,103of the plate100,100″ and may be provided at other more central areas, as shown inFIG.14A. The oblong suture holes120and the round K-wire holes126may be used as K-wire holes to allow provisional fixation of the plate100,100″ with K-wires. Additionally, the oblong suture holes120may be used for suture and an undercut122is aligned with each oblong suture hole120and extends into the inner surface107of the plate100a-100d. The undercuts122have a width that is wider than the width of the corresponding suture hole120. The undercuts122enable free passage of suture underneath the plate100,100″ without interference at the plate/bone interface. The undercuts122help reduce the moment of inertia between screw holes to allow preferential bending between holes, helping to minimize deformation of screw holes. This is useful for plate contour customization. The undercuts122also serve to further reduce the contact surface of the inner surface107of the plate100a-100d. The undercuts122may be co-located with relief cuts116and suture holes120. In the illustrated embodiments, the oblong suture holes120have a rounded triangular configuration and are positioned between screw holes130,136. With this configuration, the oblong suture holes120reduce the moment of inertia between screw holes to allow preferential bending between holes, helping to minimize deformation of screw holes. This is useful for plate contour customization. While the oblong suture holes120are illustrated with a rounded triangular configuration, other configurations may be utilized, for example, elliptical, round, oval. The oblong suture holes120also facilitate passage of suture/needles to serve as anchor points useful for reattachment and repositioning of soft tissue damaged during surgery which may aid post-surgical soft tissue healing. The oblong suture holes120also facilitate passage of suture/needles for cerclage techniques which may aid in reduction and fixation of bone fragments, particularly “butterfly” fragments on the inferior side of the bone. In the illustrated embodiment, the opposed suture holes120on either side of the plate100a-100dallow for cerclage running from one side of the plate, down under the bone, up to the opposing suture hole, and potentially across again to the originating hole for successive loops. These opposing holes120also aid cerclage perpendicular to the plate trajectory. This is the optimal angle for applying force to reduce fragments toward the plate. Referring toFIGS.16and18, each DCP slot130has an oblong configuration with tapered end walls132and a central neutral head receiving area134. Contact of a screw head133with the tapered end wall132may cause medial-lateral motion of the plate100a-100drelative to the bone to compress a bone fracture. Standard neutral placement may also be achieved by positioning the screw head in the central neutral head receiving area134. Compression or neutral placement is typically achieved using a non-locking screw131, for example, a 3.5 mm non-locking screw. The DCP slot130also enables off-axis, or oblique, screw trajectories in the plane of the slot using non-locking screws. Cancellous screws enable oblique or neutral screw trajectories through the DCP slot130, useful for fragment capture or load neutralization across the fracture line. The polyaxial holes136accept locking and non-locking screws, both inserted within a cone of angulation, as illustrated inFIG.18. The polyaxial holes136may be configured to accept different sized screws, for example, 3.5 mm screws at the midshaft end101of the plate100and 2.5 mm screws at the far lateral end103of the plate100. The nominal trajectory of the far lateral holes assists in aiming screws to good quality bone and away from the acromioclavicular joint space, as illustrated inFIG.19. As illustrated inFIGS.14A-15C, the DCP slots130and polyaxial holes136may be arranged in various configurations. In the anterior lateral plate100aillustrated inFIG.14A, the DCP slots130and the polyaxial holes136alternate in the central portion104and the end portion106while the end portion108includes consecutive polyaxial holes136. The anterior lateral plate100billustrated inFIG.14Bis similar to the plate100awherein the DCP slots130and the polyaxial holes136alternate in the central portion104and the end portion106while the end portion108includes consecutive polyaxial holes136, however the end portion108incudes additional polyaxial holes136compared to the previous embodiment. In the anterior midshaft plate100cillustrated inFIG.15A, the DCP slots130and the polyaxial holes136alternate over the length of the plate100c. In the anterior midshaft plate100dillustrated inFIGS.15B-15D, the DCP slots130and the polyaxial holes136generally alternate over the length of the plate100dwith the exception of an additional DCP slot near the end108. Other configurations other than those illustrated may also be utilized. Referring toFIGS.20A-28B, superior fixation plates200a-200din accordance with various embodiments of the disclosure will be described.FIGS.20A-20Cillustrate superior fixation plates200a,200bpositioned along a superior surface of a respective clavicle10. The superior fixation plates200a-200dare similar to the anterior fixation plates described above and each includes an elongate body202extending between opposed ends201,203with an outer surface205and an inner, bone contacting surface207. The superior fixation plates200a-200dmay include any of the features described with respect to the anterior plates, including rounded outer and inner surfaces205,207, undercuts112,114on the inner surface207, side relief cuts116, oblong suture holes120, undercuts122, round K-wire holes126, DCP slots130and polyaxial holes136. Referring toFIGS.21A-21F, the superior plates200a-200care anatomically contoured to fit along the curved anatomy of the superior clavicle. The superior plates200a-200care not interchangeable for left-side and right-side clavicles, but instead are configured for either the left-side or right-side clavicle. As the curvature of the bone varies between individuals, the superior plates200a-200care offered in multiple contours, with exemplary contours illustrated inFIGS.21A-21F. Each plate200a-200c′ has an “S” curvature in the A/P direction and a slight bow in the caudal/cranial direction. Plates200a-200c′ following contours with less (FIG.21AandFIG.21C) or more (FIG.21BorFIG.21D) “S” curvature may be referred to as “shallow” or “deep” contoured plates, respectively. As illustrated, the plates200a-200c′ may have various angles and radiuses or elliptical dimensions, however, the configurations are not limited to the illustrative examples. Selecting a contoured plate200a-200c′ closely matching the bone's contour minimizes plate prominence and irritation under soft tissue. Furthermore, as shown inFIGS.22-24C, the plates200a-200dmay have varying lengths with varying hole configurations.FIGS.22and23show superior lateral plates200a,200chaving a length longer than the length of the superior midshaft plate200dillustrated inFIGS.24A-24C. Each of the plates200a-200dgenerally include alternating DCP slots130and polyaxial holes136, however, other hole configurations may be utilized. The superior fixation plates200aand200binclude an additional hole, namely, a sliding slot240. Referring toFIGS.25A-25B, the sliding slot240has a rectangular configuration and is configured to receive a sliding slot screw241with a wide head242. The shaft of the screw241has a diameter smaller than the width of the slot240while the head242has a diameter greater than the width of the slot240. The slot240allows fine bi-directional adjustments of the plate200while maintaining provisional placement. The screw241may also be utilized for permanent fixation. The sliding slot screw and all other screws in the set may also be utilized as a stand-alone fragment capture/lag screw. Referring toFIGS.22and25A-28B, the lateral superior fixation plates200a,200binclude a lateral extension210. Such a plate200a,200bmay be used, for example, to fix fractures occurring at the far lateral end of the clavicle10. The lateral extension210contains a plurality of polyaxial holes136that allow many diverging screw trajectories to secure the plate in this thin, metaphyseal bone region, as shown inFIGS.26A-B. The polyaxial holes136accept locking and non-locking screws. For ease of surgical planning, nominal, diverging and converging trajectories are intended to secure in regions of dense bone and away from the acromioclavicular joint space. The lateral extension210also defines a plurality of oblong suture holes120similar to those in the shaft of the plate200a,200b. The lateral extension suture holes120have undercuts122′ to allow free passage of suture underneath the plate200, however, the width of these undercuts122′ is limited to the width of the suture hole120. Referring toFIGS.29-34B, superior hook plates200e,200fwill be described. The body202of the superior hook plates200e,200fis similar to the previous embodiments except that a hook member250extends from the end201′ of the plate200e,200fSuch hook plates200e,200fmay, for example, be utilized to aid healing of acromioclavicular (AC) joint separations with clavicular displacement. The hook member250includes an extension portion251which extends from the end201′ of the plate200e,200fto the postero-lateral side of the AC joint12. A descending arm252extends inferiorly from the extension portion251to a given depth from which a lateral arm254angles laterally to hook underneath the acromion14. This constrains superior displacement of the clavicle10. The hook plates are offered with various descending arm252lengths to accommodate diverse shoulder and injury anatomies. In each of the illustrated embodiments, the lateral arm254fans out into a widened head256,256′ that increases contact surface area between the hook member250and the underside of the acromion14. The widened head256,256′ may have various shapes, withFIGS.34A and34Billustrating exemplary shapes. The widened head256inFIG.34Ahas a curved spatula shape while the widened head256′ inFIG.34Bhas a curved spoon shape, each with smoothed edges. The widened heads256,256′ help to reduce painful irritation, bony erosion, and incidental fracture on the underside of the acromion14by distributing the load to a wider area. The smoothed edges of the widened head256,256′ also facilitate insertion into this soft tissue space and eventual removal, and while in place minimizes irritation to the rotator cuff and other soft tissues. Referring toFIGS.35-39, a straight fixation plate300in accordance with various embodiments of the disclosure will be described. The straight fixation plates300is similar to the anterior and superior fixation plates described above and includes an elongate body302extending between opposed ends301,303with an outer surface305and an inner, bone contacting surface307. The straight fixation plates300differs from the previously described plates in that the straight fixation plate300is not pre-bent, but instead may be configured to be bent to an appropriate curved configuration complementing the curvature of the bone to which it will be attached. That being said, the straight fixation plate300may include any of the features described with respect to the anterior and superior plates, including a wider and/or thicker central portion304, rounded outer and inner surfaces305,307, undercuts112,114on the inner surface307, side relief cuts116, oblong suture holes120, undercuts122, round K-wire holes126, DCP slots130and polyaxial holes136. The straight fixation plate300may have varying lengths with varying hole configurations. The plate300generally includes alternating DCP slots130and polyaxial holes136, with the illustrated embodiments having an additional DCP slot130in the central region. However, other hole configurations may be utilized. The straight fixation plate300does not have alternating relief cuts and suture holes like in the previous embodiments, but instead, the holes provide a combined relief cut and suture hole with undercuts. As seen inFIGS.38and39, each combined hole325includes a relief cut316and undercut322into the body302in alignment with the oblong suture hole320. As with the previous embodiments, the relief cut portions316are positioned between screw holes thereby reducing the moment of inertia between the screw holes to allow preferential bending between holes, helping to minimize deformation of the screw holes. The illustrated relief cuts316have a rounded or smooth configuration to minimize the risk of kinking or fracture. Similar to the previous embodiments, the undercuts322also help reduce the moment of inertia between screw holes to allow preferential bending between holes, helping to minimize deformation of screw holes. Furthermore, the combined holes325provide further assistance with bending. More specifically, during surgeon contouring of the plate300bby bending in the caudal/cranial direction, as illustrated inFIG.40, the side relief cut316of the combined hole325on the compression side (bottom side inFIG.40) will deform, or further “crimp”, inwards. The outer edge of the suture hole320on the tension side (upper side ofFIG.40) contains more material than is necessary for this span. This tension side will “uncrimp” or deform by necking outwards, resulting in a straighter outer plate edge. Bending to evident failure of the necked material on the tension side may be calibrated to serve as an indicator of excessive bending of the plate300, making it unusable. The intentional regions of deformation during bending created by the combined holes325may diminish bending at undesirable regions at the screw holes. Referring toFIGS.41-45, an intramedullary clavicle nail400in accordance with an embodiment of the disclosure will be described. A plurality of different sized nails400, for example, having diameters of 3.0, 3.5, 4.0, 4.5, and 5.0 mm, may be provided as a set. The nails400enable minimally invasive treatment of select clavicle fractures. Advantages of this technique are much less incision and scarring, and often elimination of soft tissue prominence. Each nail400includes an elongated body402extending from a trailing end401to a medial, leading end403. The nail body402has a pre-contoured configuration with anatomically appropriate radius RMat the medial, leading end403. The body402transitions to a straight region at the trailing end401. As shown inFIG.45, upon insertion, the trailing end401of the nail400exits the posterolateral side of the clavicle10. The nail400is then cut to length and tamped below the bone surface. Referring toFIGS.42-44, the leading end403of the nail400has a pointed shape with flats405on each side of a rounded tip407. The rounded tip407extends to a wide underside409. The pointed shape helps to advance the nail400in the medullary canal with minimal pre-drilling, while the wide underside409of the tip offers some width to rest against the canal wall. Such resistance helps to provide some rotational stability to maintain the orientation of the pre-curved nail with the restored anterior bone curvature. The orthopedic bone plates, intramedullary nails, and systems may be particularly useful in in the treatment of the clavicle. The devices may be provided with anatomic shapes suitable for fixation at distinct regions of the clavicle. It is envisioned, however, that the features of one embodiment may be combined with features of another embodiment and the disclosure and associated technology can encompass other embodiments not expressly shown or described herein. It will also be appreciated that although generally described with reference to the clavicle, it will be appreciated that the systems and devices may be adapted for use with any long bone, short bone, flat bone, or the like. While the present disclosure has been described in terms of exemplary aspects, those skilled in the art will recognize that the present disclosure can be practiced with modifications in the spirit and scope of the appended claims. These examples given above are merely illustrative and are not meant to be an exhaustive list of all possible designs, aspects, applications or modifications of the present disclosure.

11857230

SUMMARY In one embodiment the present invention is directed to a medical device, comprising: at least two bodies, wherein each of the at least two bodies are configured to be coupled to a maxilla of a patient and/or to an appliance that is at least in part extra-oral, and wherein the at least two bodies are configured to apply forces to the maxilla without any coupling of the device to the teeth of a patient. In one embodiment the present invention further comprises an adjustment mechanism configured to variably maintain a distance between the at least two bodies. In one embodiment the present invention comprises couplers configured to couple to ends of the appliance. In one embodiment the present invention comprises the appliance. In one embodiment the present invention the adjustment mechanism comprises threads. In one embodiment with the at least two bodies coupled to the hard palate, the adjustment mechanism is configured to cause lateral movement of the hard palate. In one embodiment with the at least two bodies coupled to the maxilla, an extra-oral force applied to the orthodontic appliance causes forward or a combination of forward and upward movement of the maxilla. In one embodiment with the at least two bodies coupled to the hard palate, an extra-oral protraction force applied to the appliance causes forward or a combination of forward and upward movement of the maxilla. In one embodiment the external protraction force is applied to the appliance in a direction that is in-line to the at least two bodies. In one embodiment the at least two bodies are configured to be releasably coupled to the orthodontic appliance by a fastener. In one embodiment the fastener is configured to form an interference fit, snap fit, and/or a slip fit. In one embodiment the appliance comprises an intra-oral portion and an extra-oral portion, where the intra-oral portion and the extra-oral portion are releasably coupled. In one embodiment the at least two bodies are coupled by an adjustment mechanism configured to impart lateral movement to the maxilla. In one embodiment the adjustment mechanism comprises a body with two ends that have threads at only one end. In one embodiment a first of the at least two bodies comprise at a first aperture and a second aperture, each aperture disposed along a respective longitudinal axis, wherein the axis of the first aperture is not parallel to the axis of the second aperture. In one embodiment each of the at least two bodies comprise a plurality or threaded apertures configured to receive a threaded fastener. In one embodiment the device comprises the threaded fasteners, wherein each of the threaded fasteners comprise two sets of thread, wherein one of the two sets of threads is configured to mate with a respective threaded aperture of one of the at least two bodies, and wherein a second of the two sets of threads is configured to be threadably inserted into a maxilla. In one embodiment the maxilla is the hard palate. In one embodiment each body of the at least two bodies comprises a plurality of channels each configured to receive a fastener along a longitudinal axis, wherein the longitudinal axis of at least one channel of the plurality of channels is disposed in a non-parallel relationship to a longitudinal axis of at least a second channel of the plurality of channels. In one embodiment the longitudinal axis of the at least one channel is disposed in an angular relationship with respect to the longitudinal axis of the at least a second channel that is between 1 and 60 degrees. In one embodiment, the present invention includes a maxillary expander, comprising: a pair of bodies comprised of a first body and a second body, wherein each of the pair of bodies is configured to be fixed intraorally to a palate of a patient; and a fixed aligner, wherein the fixed aligner is configured to be fastened to the pair of bodies to position the pair of bodies a predetermined distance apart. In one embodiment the present invention comprises a plurality of fasteners; a plurality of apertures formed in the pair of bodies; and a plurality of matching apertures formed in the fixed aligner; the plurality of fasteners configured to fasten the fixed aligner to the pair of bodies via insertion in the plurality of apertures in the pair of bodies and the fixed aligner. In one embodiment the present invention comprises the plurality of apertures comprise four apertures formed in the fixed aligner and two apertures formed in each of the pair of bodies. In one embodiment the present invention comprises a plurality of apertures formed in each of the pair of bodies; and a plurality of fasteners configured to fasten each of the pair of bodies body to the hard palate via insertion of the plurality of fasteners within the plurality of apertures. In one embodiment the plurality of apertures in each of the pair of bodies comprises at least three apertures. In one embodiment the fixed aligner comprises two ends, and wherein each of the pair of bodies is configured to be coupled to a respective one of the two ends. In one embodiment the fixed aligner is comprised of a wire. In one embodiment the fixed aligner consists of a single material. In one embodiment the expander is configured to be fixed to the palate with a space present between the pair of bodies and the tissue covering the palate. In one embodiment the present invention includes a maxillary expander comprising: a first pair of bodies, wherein each of the bodies is configured to be coupled to a palate of a patient; and an adjustable aligner, wherein the adjustable aligner is configured to be releasably fastened to the pair of first bodies to vary a first distance between the first pair of bodies by applying an expansionary force to the first pair of bodies. In one embodiment the adjustable aligner comprises a second pair of bodies and an expansion screw disposed between the second pair of bodies. In one embodiment the present invention comprises a pair of appliances and at least two supports, wherein each support is comprised of a first end and a second end, wherein first ends of at least two of the supports are each coupled to and extend from a respective one of the first pair of bodies, and wherein second ends of the at least two of the supports are each coupled to an appliance. In one embodiment the adjustable aligner comprises a pair of appliances each coupled to a respective one of the second pair of bodies, wherein each of the appliances is configured to match a shape of the palate. In one embodiment the appliances comprises silicone or acrylic. In one embodiment the appliances are not configured to couple to any teeth of the patient. In one embodiment each of the first pair of bodies comprises three apertures configured to receive fasteners. In one embodiment the three apertures are threaded. In one embodiment each of the second pair of bodies is configured to be coupled to respective ones of the pair of first bodies by at least two screws. In one embodiment the present invention includes a method of applying forces to an maxilla of a patient without engagement of any teeth of the patient, comprising the steps of: providing at least two bodies; coupling the at least two bodies to locations on the maxilla coupling an adjustable expander to the at least two bodies; and using the adjustable expander to apply a force to the at least two bodies to cause movement of the at least two bodies relative to one another and to cause expansion of the maxilla. In one embodiment the adjustable expander comprises threads at opposing ends of the expander. In one embodiment the movement of the at least two bodies is used to bilaterally expand the maxilla. In one embodiment the adjustable expander comprises threads at only one end of the expander. In one embodiment the movement of the at least two bodies is used to unilaterally expand the maxilla. In one embodiment the locations are on either side of the mid-palatine suture. In one embodiment the present invention includes a maxillary expander comprising: at least one pair of bodies comprised of a first body and a second body, wherein, each body of the pair of bodies is configured to be coupled intraorally to a hard palate of a patient; and an aligner, wherein the aligner is coupled to the pair of bodies and configured to position the pair of bodies a distance apart to cause expansion of the palate without any engagement of the aligner or the at least one pair of bodies with any teeth of the patient. In one embodiment the aligner comprises a fixed aligner or an adjustable aligner. In one embodiment the at least one pair of bodies is selected from the group consisting of two appliances, two wires, and two fasteners. In one embodiment each body of the pair of bodies is configured to be coupled intraorally to the palate with at least one fastener. In one embodiment each fastener comprises two parts. In one embodiment the two parts comprises threaded portions and the two threaded portions are separated by a non-threaded portion. In one embodiment the two parts are separable. In one embodiment each of the at least one pair of bodies comprises apertures configured to receive fasteners having a body with threads at a top end and a bottom end, wherein the counter sunk apertures comprise threads configured to threadably mate with the threads at the top end. In one embodiment the apertures are countersunk. In one embodiment the threads at the top end and the threads at the bottom end are separated by a non-threaded portion. In one embodiment the present invention is directed to a method of treating a maxillary deficiency, comprising the steps of: providing a pair of first bodies; coupling the pair of first bodies to a hard palate of a patient; attaching an externally worn appliance to the pair of first bodies; and applying a protraction force to the appliance to cause forward movement of the pair of first bodies. In one embodiment the method provides an expander between the pair of first bodies; and causing the expander to move to cause lateral movement the pair of first bodies relative to one another. In one embodiment the protraction force is aligned to cause only forward or forward and upward movement of the patient's maxilla. In one embodiment the protraction force generates little or no moments at the pair of first bodies. In one embodiment protraction force is applied in a direction that passes through the pair of first bodies and a point on the appliance where the force is applied to. In one embodiment the present invention is directed to a method of laterally expanding a maxilla of a patient, comprising the steps of: intraorally attaching a pair of first bodies to the maxilla while maintaining a first space between the first bodies; attaching an adjustable aligner to the pair of first bodies; adjusting the adjustable aligner to cause an expansionary force to be applied to the pair of first bodies such that the first space is changed to a second space change; removing the adjustable aligner from the pair of first bodies; and affixing a first fixed aligner to the pair of first bodies to maintain the second space between the first bodies. In one embodiment the step of creating a first space between the bodies comprises affixing a second first fixed aligner to the pair of first bodies to create the first space; and subsequently removing the first fixed aligner from the pair of first bodies before attaching the adjustable aligner. In one embodiment the method comprise a step of affixing an appliance to each of the bodies. In one embodiment the method comprises a step of coupling the appliance to a hard palate and not to any of the teeth of the patient. In one embodiment each of the pair of first bodies is affixed to the palate on either side of the median palatine suture. In one embodiment the step of intraorally attaching the bodies includes a step of inserting at least three fasteners through each body and into the hard palate. In one embodiment the present invention is directed to a method of expanding a median palatine suture, comprising the steps of: providing a pair of first bodies; providing a pair of acrylic appliances; intraorally coupling the pair of first bodies and the pair of acrylic appliances to a hard palate while maintaining a first distance between the pair of first bodies; and applying an expansionary force to the first bodies such to change the first distance between the first bodies to a second distance. In one embodiment the present invention is directed to a method of expanding a maxilla, comprising the steps of: providing a pair of first bodies; coupling the pair of first bodies to a hard palate; attaching an aligner to the pair of first bodies; maintaining the pair of first bodies a distance below and apart from the hard palate. In one embodiment the aligner is an adjustable aligner. In one embodiment the aligner is a first fixed aligner. In one embodiment the distance is between 0.1 to 3 mm. In one embodiment the method comprises providing a spacer to between the pair of first bodies and the hard palate. In one embodiment coupling comprises use of threaded fasteners. In one embodiment the distance is maintained via locking of threads of the threaded fastener into the pair of first bodies. In one embodiment, the present invention comprises a maxillary expander, comprising: at least two bodies, wherein each of the at least two bodies are configured to be coupled to a hard palate with a first distance between the at least two bodies and the palate; and an expander configured to maintain a second distance between the at least two bodies. In one embodiment the expander comprises ends that are threaded. In one embodiment the expander comprises only one end that is threaded. In one embodiment further comprises an aligner. In one embodiment the aligner comprises at least one body configured to be attached to the at least two of the bodies. In one embodiment, the aligner comprises a fixed aligner. In one embodiment aligner comprises an adjustable aligner. In one embodiment the aligner comprises the expander. In one embodiment the at least two bodies are configured to receive fasteners. In one embodiment the fasteners are configured to be received by at least one lateral support extending from each of the at least two bodies. In one embodiment the fasteners comprise screws. In one embodiment the fasteners comprise two threaded portions, wherein an outermost diameter of one or the two threaded portions is smaller than an outermost diameter of a second of the two threaded portions. In one embodiment the two threaded portions are separated by a non-threaded portion. In one embodiment the at least two bodies are disposed in a parallel relationship with respect to each other. In one embodiment the present invention comprises a method of laterally expanding a maxilla, comprising the steps of: providing at least two bodies; coupling the at least two bodies to a hard palate; and attaching at least one aligner to the at least two bodies. In one embodiment the at least one aligner comprises a fixed aligner and/or an adjustable aligner. In one embodiment attaching the at least one aligner comprises attaching a fixed aligner and an adjustable aligner. In one embodiment the at least two bodies comprise fasteners. In one embodiment fasteners comprise threaded fasteners. In one embodiment the present invention includes a medical device, comprising: at least two bodies configured to be coupled to a patient's maxilla, wherein each of the at least two bodies are configured to be coupled to an appliance that is at least in part extra-oral, wherein the appliance is configured to apply an extra-oral protraction force to the at least two bodies, and wherein the two bodies are configured to transfer the extra-oral force to the maxilla to cause movement and growth of the maxilla. In one embodiment the at least two bodies further comprising couplers configured to couple to ends of the orthodontic appliance. In one embodiment the device comprises the appliance. In one embodiment the appliance comprises an orthodontic face bow. In one embodiment an adjustment mechanism, wherein with the at least two bodies coupled to the maxilla, the adjustment mechanism is configured to transfer forces to the at least two bodies to cause the at least two bodies to apply forces to the maxilla and to cause lateral movement of the maxilla. In one embodiment with the at least two bodies coupled to the maxilla, an extra-oral force applied to the at least two bodies by the appliance causes forward or a combination of forward and upward movement of the maxilla. In one embodiment the external protraction force is applied to the appliance in a direction that that in-line to the at least two bodies. In one embodiment the at least two bodies are configured to be releasably coupled to the orthodontic appliance. In one embodiment the releasable coupling comprises an interference fit, snap fit, and/or a slip fit. In one embodiment the appliance comprises an intra-oral portion and an extra-oral portion, where the intra-oral portion and the extra-oral portion are releasably coupled. In one embodiment a first of the at least two bodies comprise at least a first aperture and a second aperture, each aperture disposed along a respective longitudinal axis, wherein the axis of the first aperture is not parallel to the axis of the second aperture. In one embodiment each of the at least two bodies comprise a plurality or threaded apertures configured to receive a threaded fastener. In one embodiment the device comprises the threaded fasteners, wherein each of the threaded fasteners comprise two sets of threads, wherein one of the two sets of threads is configured to mate with a respective threaded aperture of one of the at least two bodies, and wherein a second of the two sets of threads is configured to be threadably inserted into a maxilla. In one embodiment each body of the at least two bodies comprises a plurality of channels each configured to receive a fastener along a longitudinal axis, wherein the longitudinal axis of at least one channel of the plurality of channels is disposed in a non-parallel relationship to a longitudinal axis of at least a second channel of the plurality of channels. In one embodiment the longitudinal axis of the at least one channel is disposed in an angular relationship with respect to the longitudinal axis of the at least a second channel that is between 1 and 60 degrees. The above should not limit the present invention as other advantages, benefits and embodiments are also within the scope of the invention as described in the detailed description below. DETAILED DESCRIPTION The figures referenced below refer to components and features of the present invention with reference indicators. Although same components may be shown in different figures, it should be noted that cumulative use of indicators with same components is not used when their use would be superfluous and/or make components more difficult to identify. Referring toFIGS.1a-c, there are seen representations of components of a skeletal anchorage device before being coupled intraorally to a patient's maxilla on either side of the median palatine suture. In one embodiment, a skeletal anchorage device of the present invention comprises a pair of first bodies100a-b(only one body shown inFIG.1a) configured for intra-oral attachment to the maxilla along the upper palate on either side of the median palatine suture. In one embodiment, each body comprises a side configured to face the hard palate and an opposite top side. In one embodiment, one or both sides are flat. In other embodiments, the sides are parallel to each other. In one embodiment, at least a portion of one side is not parallel to the other side. In one embodiment, each of the first bodies100a-bcomprises a plurality of first apertures101and a plurality of second apertures102disposed along a longitudinal axis each first bodies. In one embodiment each first body comprises three first apertures101and two second apertures102. In one embodiment, first apertures101extend through a thickness of the first bodies100a-b. In one embodiment, second apertures102extend only a certain distance into the first bodies100a-band not all the way through. In one embodiment, the skeletal anchorage expander device also comprises a first fixed aligner106having a plurality of third apertures199configured to receive threaded first fasteners110. In one embodiment, first fasteners110comprise screws configured to be received through the third apertures199and threadably screwed into the second apertures102. In one embodiment, an equal number of third apertures199are formed on a lateral first left side of the first fixed aligner106as are formed on an opposite lateral right second side. In one embodiment, fixed aligner106comprises four third apertures199. In one embodiment, fixed aligner106comprises a single integral body. In one embodiment, first fixed aligner106comprises a plate like structure. In one embodiment, the first fixed aligner106comprises an H-shaped geometry. In other embodiments, first fixed aligner comprises a geometry capable of having apertures formed at 4 corners. In one embodiment, third apertures199of the first fixed aligner106are configured with a longitudinal spacing “B” that enable them to be coupled to respective second apertures102of the pair of first bodies100a-bwith first fasteners110inserted in the apertures. In one embodiment, when the pair or first bodies100a-bare coupled to the first fixed aligner106via fasteners, a lateral spacing of the third apertures199results in the pair of first bodies100a-bbeing separated by a distance “Z”. In one embodiment, first apertures101comprise a channel where the channel is counter sunk into first bodies100a-bto a first depth that is less than a thickness of the first bodies and such that the channel is threaded along the first depth and configured to threadably receive threaded upper end of second fasteners111(FIGS.2b-c) during screwable insertion of threaded bottom ends of the second fasteners into the palate. In one embodiment, first fixed aligner106and each first body100a-bare dimensioned with the dimensions noted inFIGS.1aand1b. In one embodiment of use (seeFIG.1c), a hard palate facing side of first fixed aligner106is positioned over respective bodies100a-b, respective first fasteners110are inserted through the third apertures199of the first fixed aligner106, and respective fasteners110are screwed into second apertures102to couple the first fixed aligner106to the pair of first bodies100a-b. After first fixed aligner106and the pair of first bodies100a-bare coupled, the combination is positioned over a hard palate of a patient such that one of first bodies100a-bis positioned on one side of the median palatine suture of the patient and the other of first bodies100a-bis positioned on the other side of the suture. Referring toFIGS.2a-b, there are seen representations of components of a skeletal anchorage expander device during their coupling to the hard palate on either side of the median palatine suture. In one embodiment of use, after the first fixed aligner106and the pair of first bodies100a-bare coupled to each other, they are positioned over the hard palate on either side of the median palatine suture and the combination is coupled to the hard palate via a plurality of threadable second fasteners111. In one embodiment, each of the first bodies comprises a plurality of threaded first apertures101that extend between a hard palate facing side and an opposite side of the pair of first bodies. In one embodiment, each of the pair of first bodies100a-bcomprises three threaded first apertures101. In one embodiment, threadable second fasteners111comprise a bottom portion configured to screw into the hard palate via a set of first threads and a top portion configured to screw into first apertures101via a second set of threads. In one embodiment, the first and second set of threads are separated by an unthreaded portion. In one embodiment the first set of threads are defied by an outer diameter that is smaller than an outer diameter of the second set of threads. In one embodiment, second fasteners111are dimensioned with the dimensions given inFIG.2b. In one embodiment of use, bottom portions of second fasteners111are inserted through a respective first apertures101in the pair of first bodies100a-b, and after insertion, the bottom portions of the second fasteners111are screwably inserted into the hard palate. During insertion of the bottom ends of second fasteners into the hard palate, the top portions of second fasteners111are screwed into respective threads of first apertures101in the pair of first bodies100a-buntil a surface portion at a top of the second fasteners111becomes seated against a surface portion of the first apertures111. In one embodiment, a torque between about 0.1 and 0.6 nm is applied to the second fasteners to cause them to be inserted into both cortical bones of the palatal process of the maxilla and to achieve seating against and in the first bodies. In one embodiment, when second fasteners111are seated against and in the first bodies100a-b, a fixed rigid structure is formed, which rigid structure is made even more rigid via insertion of the second fasteners into the hard palate. In one embodiment, before insertion of the bottom end of second fasteners111into a hard palate, one or more spacer50is inserted between a hard palate facing side of the pair of first bodies100a-band the hard palate. The one or more spacer is intended to define a distance between the pair of first bodies100a-band tissue covering the hard palate. In one embodiment, the distance is 0.1-3 mm. In one embodiment of use, second fasteners111are screwed into the hard palate until the pair of first bodies100a-blightly abut against the one or more spacer50and such that the one or more spacer lightly abuts against tissue of the hard palate. In one embodiment, spacer50comprises soft silicon. In another embodiment, spacer50is made of material that is capable of being dissolved by fluids in the mouth. In one embodiment, spacer50comprises a material comprising gluten free wheat, yeast, salt and water that is formed by baking into a thin wafer that is capable dissolving very rapidly when exposed to secretions within the mouth. In other embodiments the spacer comprises resin or polycarbonate. After insertion of one or more spacer50and coupling of a pair of first bodies100a-bto the hard palate, in one embodiment, the spacer is removed or is allowed to dissolve to leave an open space/air gap between the first bodies and the hard palate. In one embodiment, the space/air gap enables that no, or very minimal contact, is made between the first bodies100a-band the hard palate, which reduces the potential for tissue necrosis to occur. In doing so, since contact with the hard palate by the first bodies100a-bis reduced, damage and irritation (necrosis) of the palatal soft tissue is reduced, and forces to the maxilla bone are maximized. The present invention should not be limited to formation of a space/gap via that use of the described spacer(s) as other methods can also be used, for example, via temporary anchorage of a pair of first bodies to teeth with a surgical guide so as to create the space/gap during insertion of second fasteners111, where after creation of the space, the temporary anchorage can be removed. Further, while threadable insertion of the top ends of the second fasteners into a pair first bodies is described to rigidly couple second fasteners111to the bodies in a position below the palate, the present invention should not be limited to use or threads to achieve such coupling, as in other embodiments, biocompatible resins or adhesives; or clamping, locking, and interference fit type coupling mechanisms could be used to couple second fasteners111to a pair of first bodies in addition to, or in lieu of, the second set of threads described above. With reference toFIG.3, there is seen a representation of components of a skeletal anchorage expander device after a pair of first bodies has been coupled to a palate of a patient and after a first fixed aligner is removed. In one embodiment of use, after second fasteners111are coupled to a hard palate of a patient, first fasteners110are uncoupled from first bodies100a-b, and first fixed aligner106is uncoupled from the pair of first bodies100a-band removed. After removal, it is identified that the pair of first bodies100a-bwill be separated by a distance “D” as was determined by distance “B” of first fixed aligner106(seeFIG.1b). Referring now toFIGS.4a-j, there are seen a representations of components of a skeletal anchorage expander device comprised of an adjustable aligner and/or a pair of first bodies that are configured to effectuate movement and growth of the maxillary skeletal complex of a patient. In one embodiment, a skeletal anchorage expander device of the present invention comprises an adjustable aligner150(seeFIG.4a). In one embodiment, the adjustable aligner150comprises a pair of second bodies151a-b, where each body is coupled by at least one adjustment mechanism formed therebetween. In one embodiment, each of the second bodies151a-bis elongated along an axis. In one embodiment, when coupled by an adjustment mechanism152, each axis is generally parallel to the other axis. In one embodiment, the adjustment mechanism152comprises a double ended expansion screw having threads at both of its ends. In one embodiment, the adjustment mechanism152is configured to be rotated relative to the pair of second bodies151a-bso as to cause each of the second bodies to move toward or away from each other via threaded interaction of its ends with threaded apertures in each of the second bodies. In one embodiment, each pair of second bodies151a-bis configured with apertures dimensioned to slideably receive ends of one or more stabilizing rod175thereinto or therethrough. In one embodiment, each of the second bodies151a-bcomprise a plurality of threaded fourth apertures198configured to extend between a hard palate facing bottom side and a top side of the second bodies151a-b. In one embodiment, fourth apertures198are longitudinally spaced apart to match the longitudinal spacing between second apertures102of each of the pair of first bodies. In one embodiment of use, adjustment mechanism152is rotated to a position that enables threadable first fasteners110to be aligned to and easily inserted through respective fourth apertures198of adjustable aligner150and into respective apertures102of each of the pair of bodies100a-b. After being coupled in this manner, the pair of second bodies151a-bwill be spaced apart by the same initial distance “D” as the first bodies100a-bare spaced apart from each other. After coupling, adjustment mechanism152can be used to increase or decrease the lateral distance between the pair of second bodies151a-b, the pair of first bodies100a-band the first fasteners110, which change in distance can be used to treat a maxillary deficiency of a patient by bi-laterally expanding the maxillary skeletal complex and the 9 bones that articulate with the maxilla. In one embodiment, instead of an adjustment mechanism152comprised of a double ended expansion screw having threads at both of its ends as described above, an adjustment mechanism162comprises a unilateral expansion screw (seeFIG.4d) where one end of the unilateral expansion screw is threaded and the other is not. In one embodiment, the non-threaded end is inserted into and through an aperture of one of the second bodies151a-band left to spin freely within the aperture, while the threaded end is coupled via its threads to a threaded aperture within the other body. The non-threaded end is secured by retainer, for example a circle-clip, at its end to limit longitudinal movement within the aperture relative to the second body. When adjustment mechanism162is rotated, one of the second bodies151a-bremains fixed and the other moves. In one embodiment of use, it is identified that a skeletal anchorage expander device comprised of a unilateral expansion screw as described above can, thus, be used to treat maxillary asymmetry. Although rotation is described above to effect an increase in distance between second bodies151a-b, it is contemplated that other mechanisms capable of causing movements of the second bodies151a-bare within the scope of the present invention, for example a spring, a micro-motor, or some other passive or active actuator could be used to effect linear movement between the second bodies. In one embodiment, after coupling of each of the pair of first bodies100a-bto the hard palate, a total of six fasteners will have been used, three per each first body100a-b. Compared to use of two second fasteners per first body100a-b, the present invention's use of three second fasteners per first body enables lessening of forces the fasteners experience during movements of the first bodies as well as lessening of forces experience by local bone supporting the fasteners. Use of more second fasteners111distributes the force applied to the fasteners by the resistance by the resistance of the palate to movement generated of the second bodies151a-band reduces the force experienced by any one fastener. Accordingly, in other embodiments, as needed or desired, to lessen forces experienced by fasteners and/or local bone supporting the fasteners, more than three second fasteners111and more than three apertures in first bodies to receive the fasteners are within the scope of the invention. With reference toFIG.4e, although some embodiments above described use of a fixed aligner106to provide initial alignment to a pair of first bodies, in one embodiment, such alignment can be provided without use of aligner106. In one embodiment of use, threadable first fasteners110are inserted through respective fourth apertures198of a pair of second bodies151a-band then screwed into respective second apertures102of a pair of first bodies100a-b. After being coupled in this manner, the pair of first bodies100a-bwill be spaced apart by an initial distance determined by how much expansion mechanism152or162will have been rotated. The pair of first bodies100a-b, can thereafter be coupled to the upper palate with this initial spacing by first inserting four second fasteners111into first apertures101at both ends of the pair of first bodies100a-b. After coupling to the upper palate, the pair of second bodies151a-bcan be removed and as desired two additional second fasteners111can be used to secure the pair of first bodies to the hard palate via insertion into first apertures101in the middle of the pair of first bodies100a-bto. Once the first bodies100a-bare coupled to the upper palate with a full complement of second fasteners111, the pair of second bodies151a-bcan be recoupled to the pair of first bodies100a-bfor use via insertion of threadable first fasteners110into fourth apertures198and then via further insertion into respective second apertures102of the pair of first bodies100a-b. Embodiments of adjustable aligner150described have been found useful when an initial distance between second bodies151a-bis desired to be minimized (see adjustable aligner150inFIG.4fsans stabilizing rods175), for example, when the first100a-bor second151a-bbodies are initially desired to be mounted as close to the palatal suture as possible, where in such an orientation force transmission to resisting sutural tissue is maximized. As seen inFIG.4g, although in one embodiment adjustment mechanism152between the second bodies151a-benables a minimum distance of 2.5 mm between the second bodies to be achieved, it also determines a maximum distance 10 mm, and as well determines how far outward ends of adjustment mechanism152protrude outward from the second bodies in the minimized orientation inFIG.4f. However, it is identified that in some instances, when the ends of adjustment mechanism protrude too far, the protrusion can cause interference with the anatomy of a patient's tongue or mouth. Further, when expansionary forces are applied to the second bodies151a-b, in palates with minimal space, the bodies can begin to dig into the palatal wall tissue due to insufficient transverse space. With reference toFIG.4h, to minimize or eliminate interference with a patient's oral anatomy, in some embodiments, adjustable aligner150comprises an adjustment mechanism172. In one embodiment, adjustment mechanism172comprises a telescopic expansion screw mechanism. In one embodiment, the expansion screw mechanism comprises a housing172ahaving two threaded apertures at opposite ends and two threaded rods172beach have a first threadable end threadably mounted in a respective threaded aperture and a second threaded end mounted within a respective threaded aperture of a second body. In one embodiment of use, rather than using only one of adjustment mechanisms152or172to achieve a desired expansion of a patient's maxilla/palate, it may be desired to use both. For example, where an initial close placement of first or second bodies to a palatal suture is desired and a subsequent expansion greater than capable of being provided by adjustment mechanism152without causing interference by the adjustment mechanism is desired, an adjustable aligner150comprised of adjustment mechanism152can be used to achieve a first distance between second bodies (for example a distance of 10 mm), whereafter the first distance is achieved, and the adjustable aligner can be removed and replaced with an adjustable aligner150comprised of an adjustment mechanism172to achieve a second distance (15 mm) between the second bodies. The initial and final distances described above with regard to use of adjustment mechanism's152and172are intended to be exemplary as in other embodiments adjustment mechanisms152and172can be configured enable smaller or larger distances, for example, via appropriate selection of their lengths and/or modification of the bodies. Referring toFIGS.5a-b, there are seen representations of components a skeletal anchorage expander device, including of a pair of first bodies and a pair of appliances before the appliances are coupled to the pair of first bodies. In some cases, the combination of adjustable aligner150, first bodies100a-b, and fasteners111may be insufficient to achieve a clinically desired expansion of the maxilla due to very thin bone or very thick bone anatomy. Accordingly, to further reduce bone stresses by threaded fasteners, in one embodiment, a skeletal anchorage expander device of the present invention comprises a pair of appliances120a-b. In one embodiment each appliance comprises at least one extending support125(seeFIG.5b). In one embodiment of use, a first end130of each support125is configured to be coupled to a respective second aperture102of the pair of first bodies100a-b, and an opposite second end131of the supports is embedded within a respective plate132. In one embodiment, each plate comprises acrylic or other sufficiently rigid biocompatible material as is known to be used by those skilled in the dental appliance arts. In one embodiment, when embedded within plate132, first ends130of each extending support125are spaced apart by the same distance “Y” as are second apertures102of each of the pair of first bodies100a-b. In one embodiment, each first end130comprises an aperture configured to receive a respective fastener110therethrough. In one embodiment, plates132are made and dimensioned from a mold or digital scan made of the mouth so that when used intraorally, they comfortably abut against the palatal tissue without any direct contact being made with any teeth. Referring toFIGS.6a-d, there are seen representations of components of a skeletal anchorage expander device including a pair of appliances coupled to a pair of first bodies before and after an adjustable aligner is coupled to the pair of first bodies and the appliances. In one embodiment of use, threadable first fasteners110are inserted through respective fourth apertures198of adjustable aligner150, through respective apertures in first ends130of extending supports125of appliances120a-b(seeFIGS.6a-b), and then screwed into respective second apertures102of the pair of first bodies100a-bto cause the three coupled components to form a structure that when coupled to a palate and expanded via adjustment screw152enables additional forces to be applied on either side of the palatal suture. In one embodiment (seeFIG.6c), rather than initially provide appliances120a-bas units separate from that of adjustable aligner150, each appliance is integrated to be part of respective second body151a-b, such that the adjustable aligner150and each appliance can be attached to the pair of first bodies100a-bas a single integral unit.FIG.6drepresents one such integration, where a set of first end of supports125is integrated into a second body and where the opposite set of ends can be molded over by a plate (not shown). Referring toFIGS.7a-b, there are seen representations of components of a skeletal anchorage expander device comprised of appliances before and after a distance between an adjustable aligner is increased by an adjustment mechanism. In one embodiment of use, adjustable aligner150is coupled to a pair of first bodies100a-band a distance between the pair of second bodies151a-bis increased via rotation of adjustment mechanism152, which increase causes a distance between the first bodies100a-band appliances120a-bto be increased. In embodiments, the increase is effected via use of a spanner wrench, activation key, or other device configured to move or rotate adjustment mechanism152/162. In one embodiment, an incremental increase in a distance between second bodies151a-bcauses lateral expansion of the maxilla of a patient, where the amount of increase is determinative of the amount of potential expansion and that can be achieved. During use of adjustable aligner150, it is identified that portions of second fasteners111at their insertion point into the hard palate are exposed by the small space/gap created between the hard palate and the pair of first bodies100a-b(see use of spacer50to create space/gap in discussion ofFIG.2above). Compared to if the small space did not exist, the existence of a space causes an increase in the amount of stress the second fasteners are subject too at their insertion point into the hard palate via the aforementioned resistance to movement by the palatine suture at one end of the second fasteners and the movement applied by the second bodies151a-bat the other end of the fasteners. The stresses applied to the fasteners111implies the hard palate at each of the insertion points will also be subject to the stress. A reduction of local stresses applied to fasteners111and the maxilla bone is thus identified as being desired. One approach to reduce fastener stress includes distributing the stress over more fasteners as discussed above. However, when appliances120a-bare also used, since their plates132abut against the palate, expansion of the second bodies151a-bwill cause the plates to apply forces to the soft palate and thus the hard palate which forces can be used to at least partially overcome the resistance to expansion by the maxilla, which in turn can be used to further reduce stresses experienced by the fasteners. Threadable insertion of the top ends of the second fasteners111into respective threaded apertures of the pair of first bodies100a-b, the use of more than two second fasteners111per first body, and the use of appliances as described above can be used alone or in combination to provide stability of the pair of first bodies100a-band second bodies151a-bsuch that molar and tooth borne anchorage devices do not necessarily need to be used. By eliminating force transmission to the teeth, many benefits are derived, namely, greater orthopedic effects occur relative to alveolar or tooth effects. Greater orthopedic effects are correlated with greater airway and aesthetic benefits. Moreover, many risks are eliminated by the non-involvement and contact with the teeth, including root resorption, tooth tipping, and potentially a scissors bite. Although non-involvement and contact with teeth is preferred, it should be understood that nothing precludes embodiments of the present invention described above or further below from being coupled to the teeth when desired or needed to achieve a particular clinical outcome. Referring toFIG.8, there are seen representation of a pair of first bodies after a distance between the adjustable aligner is increased by a clinically desired amount the adjustable aligner and appliances are removed. In one embodiment of use, after a distance between a pair of first bodies100a-bis increased to a clinically desired distance “D2”, first fasteners110are unscrewed, and adjustable aligner150and, if used, appliances120a-bare removed. In one embodiment, to enable regrowth of the palatine suture while distance “D2” is maintained, a pair of third bodies170a-bare positioned over the pair of first bodies100a-b. In one embodiment, each of the third bodies170a-bcomprise a plurality of fifth apertures195each being longitudinally spaced apart with the same spacing as the second apertures102of each first body. In one embodiment, apertures195extend from a palatal facing side to a top side of the pair of third bodies170a-band are configured to receive fifth fasteners191therethrough. Referring toFIG.9, there are seen representations of a pair of first bodies and a pair of third bodies after the pair third bodies170a-bare coupled to the pair of first bodies via respective fifth fasteners191being inserted into respective fifth apertures195, and the respective fifth fasteners being screwed into respective second apertures102of the pair of first bodies100a-bto couple the third bodies to the first bodies. Referring toFIGS.10a-d, there are seen representations of components of a skeletal anchorage expander device, including a second fixed aligner. In one embodiment of use, to maintain distance “D2” while first bodies100a-band third bodies170a-bare coupled together, a second fixed aligner196is used. In one embodiment second fixed aligner196comprises a body configured with a shape that maintains distance “D2” over a holding/stabilizing phase during which a palatine suture of a patient is allowed to regrow with bone and to maintain the distance “D2” on its own and without use of embodiments of the present invention. In one embodiment, second fixed aligner196is configured to couple third bodies170a-btogether. In one embodiment, second fixed aligner196comprises a wire bent into a shape that allows insertion of its ends166and167into respective sixth apertures197formed in each of the pair of third bodies170a-b. In one embodiment, second fixed aligner196is manufactured as a single piece from stainless steel spring metal. In one embodiment, second fixed aligner170a-bis manufactured of a material that is sufficiently strong enough to maintain distance ‘D2” during the holding/stabilizing phase. Use of fixed aligner196during the holding/stabilizing phase instead of an adjustable presents a far sleeker and less bulky apparatus that enables greater tongue volume and tongue posture during the phase. Furthermore, removal of the adjustable aligner after an achieved expansion enables greater hygiene and sanitation. In other embodiments, however, after an achieved expansion, the adjustable expander can be left in place with no further adjusts being made to effectively function as a fixed aligner. Referring toFIGS.11a-bthere are seen representations of a skeletal anchorage expander device comprised of additional bodies. In some embodiments, during expansion of a patient's maxillary complex, a patient's age, gender, bone density, or a desired clinical outcome may require an amount of stability that some of the embodiments described above are not best suited to provide. Accordingly, in one embodiment, a skeletal anchorage expander is provided with at least two additional bodies165. In embodiments, bodies165comprise extending arms, rods, stiff wires or other structures configured to provide additional points of stability to the skeletal anchorage expander without reliance on support of the teeth. In one embodiment, at least one body extends laterally from each of first bodies100a-b(seeFIG.11a) or from each of second bodies151-a-b(seeFIG.11b). In one embodiment, one end of each body165is integrated with first bodies100a-bor second bodies each body165, and another end comprises an attachment mechanism164configured to provide a coupling to the hard palate. In one embodiment, each attachment mechanism is configured to receive a fastener163configured to provide releasable coupling of the attachment mechanism to the hard palate. In embodiments, fastener163can comprise screws, rivets, pins, interference type mechanism biocompatible adhesives or other dental fasteners known in the arts. Use of bodies165provides additional coupling points via which forces can be distributed across more points of attachment of a skeletal anchorage device to the palate. Referring toFIGS.12a-c, there are seen representations of a skeletal anchorage expander device that does not necessarily rely on the use of a pair of first bodies. In one embodiment, a skeletal anchorage expander comprises an adjustable aligner151or a fixed aligner106. In one embodiment, a skeletal anchorage expander comprises a plurality of sixth fasteners136. One bottom end of each sixth fastener136is configured to be inserted into the maxilla and an opposite top end is configured to receive and be coupled to a fixed aligner106or an adjustable aligner150. In one embodiment, a respective alignment and spacing of each sixth fastener136relative to other sixth fasteners that are coupled to a patient's hard palate is determined by spacings of apertures formed through fixed aligner106. In one embodiment, top ends of sixth fasteners136are initially coupled to fixed aligner106via interference fitment with recesses formed in the bottom of the apertures formed in the fixed aligner106, where after fitment each sixth fastener extend from and is aligned with the apertures. In one embodiment of use, the fixed aligner106and sixth fasteners136are aligned to and positioned against the palate so that an equal number of sixth fasteners136are positioned on either side of the palatine suture. In one embodiment of use, each fastener is subsequently coupled to the hard palate. In one embodiment, the bottom end of each sixth fastener136comprises threads that are inserted into the hard palate via rotatable interaction with the top ends of each fastener thorough the apertures in fixed aligner106. In one embodiment of use, after insertion of each sixth fastener136to a desired depth, fixed aligner106is decoupled from sixth fasteners136via removal of the top ends of the sixth fasteners from the recesses in the apertures of fixed aligner. In one embodiment of use, an adjustable aligner150is coupled to the sixth fasteners136. In one embodiment, attachment mechanisms are provided with or in each second body151a-band are dimensioned to be longitudinally spaced apart with the same longitudinal spacing as the apertures of fixed aligner106. In one embodiment, before coupling sixth fasteners136, the second bodies151a-bare spaced apart using an adjustment mechanism152to provide the attachment mechanism in the second bodies151a-bwith the same lateral spacing as that of the apertures of fixed aligner106. In one embodiment, each attachment mechanism in adjustable aligner150is configured such that when adjustable aligner150is placed over sixth fasteners136, the attachment mechanism retains adjustable aligner150. In embodiments, the attachment mechanisms comprise, apertures, snap fit mechanisms, interference type mechanisms, adhesive or combinations thereof that are configured to allow sixth fasteners135to be coupled and decoupled to the adjustable aligner150. In one embodiment, attachment mechanisms comprise apertures and seventh fasteners135that are provided in and with each second body151a-b, where seventh fasteners comprise fasteners and where top ends of sixth fasteners136are provided with apertures to receive bottom ends of seventh fasteners135. In one embodiment top ends of sixth fasteners136and bottom ends of seventh fasteners135are threaded. In one embodiment of use, after adjustable aligner150is positioned over sixth fasteners136, seventh fasteners135are inserted into apertures of adjustable aligner and coupled to sixth fasteners136. Subsequently, adjustable aligner151can be used to generate therapeutic expansionary forces to alignably installed sixth fasteners136, without the need to use first bodies100a-bdescribed above. Further, in as much as sixth fasteners135can be installed into the palate to a desired depth, in one embodiment, installation may be performed such that the top ends of the sixth fasteners135can protrude a particular distance below the palate, in which case, one or more spacer50as described above may not be needed to achieve a desired mounting space/gap between adjustable aligner150and tissue of the palate. Although four sixth136and seventh135fasteners are represented byFIGS.12a-b, other numbers of fasteners and attachment mechanism are understood to be capable of implementation and use, for example, six or more sixth and seventh fasteners, and respective six or more attachment mechanisms can used as may be desired or needed to distribute forces experienced by the fasteners. Referring toFIG.13, there are seen representations of another embodiment of a skeletal anchorage expander device that does not require use of first bodies100a-b. In another embodiment, where a pair of first bodies100a-bdiscussed above need not be used, each of the second bodies151a-bcomprise a plurality of threaded fourth apertures198that are configured to extend between a hard palate facing bottom side and a top side of the second bodies151a-b. Although four threaded apertures198are discussed herein, the present invention contemplates other numbers of fourth apertures can be implemented within each of the second bodies151a-bto better distribute forces and decrease screw and bone stress. In one embodiment of use, pair of second bodies151a-bare first coupled to the upper palate by inserting bottom ends second fasteners111into fourth apertures198, and after insertion the bottom ends of the second fasteners111are screwably inserted into the hard palate. During insertion of the bottom end into the hard palate, the top end of second fasteners111are screwed into respective threaded fourth apertures198in the pair of second bodies151a-b. In one embodiment, before full screwable insertion of the second fasteners111into the palate, a spacer50may be used to create a distance between the pair of second bodies151a-band the palate. In one embodiment, when used without the pair of first bodies as described above, the pair of second bodies151a-bcan be coupled to or comprise an appliance, arm, rod, stiff wire or other structure configured to provide additional points of stability to the skeletal anchorage expander as described above. Comparison of a prior art device against various embodiments of the present invention were performed, including for:Prior Art device: an expander assembly coupled to the teeth via molar bands and to the palate via 4 fasteners each comprised of a single set of thread configured to be threadably inserted into the palate (i.e. Moon device referenced in Background)Embodiment 1: An expander assembly using an adjustable aligner150coupled to the palate via a pair of first bodies100a-band six fasteners111, where each fastener comprises two sets of threads, and where one set of threads is threadably coupled to the pair of first bodies and the second set of threads is threadably coupled to the palate (seeFIG.2b).Embodiment 2: An expander assembly using an adjustable aligner150coupled to the palate via a set of two bodies120a-b(seeFIG.6b) and a pair of first bodies100a-band six fasteners111, where each fastener comprises two sets of threads (seeFIG.2b), and where one set of threads is threadably coupled to the pair of first bodies and the second set of threads is threadably coupled to the palate (seeFIG.2b). The following peak bone stresses were noted:Prior Art device: 98 MPaEmbodiment 1: 84 MPa (provided reduced stresses to fasteners and bone compared to prior art).Embodiment 2: 50 MPa (provided reduced stresses to fasteners and bone compared to prior art). The following peak palatine strains were noted:Prior Art device: 0.479Embodiment 1: 0.426 (provided more uniform strain to the palatine suture compared to prior art).Embodiment 2: 0.397 (provided more uniform strain to the palatine suture compared to prior art and embodiment 1). Referring toFIG.14, there is seen a representation of a third fixed fastener. In one embodiment, a third fixed aligner1901comprises a surgical guide that is configured to accurately position and fixate a pair of first bodies100a-bto the palate on either side of the palatal suture. In one embodiment, a cast of a patient's intra-oral geometry is obtained, a mold is made from the cast, and an appliance is made from the mold in the form of a third fixed aligner1901that has matching features of the patient's palate, jaw and/or dentition formed in its palate facing surface. In another embodiment, a digital scan (for example, a palatal and/or a CBCT scan of the upper jaw) is performed via a computer-controlled imaging device and a representation of the patient's palate, jaw and/or dentition is obtained and stored in memory (for example, as an STL file). The stored representation can subsequently be used by a 3d printing or machining device to form a third fixed aligner1901that has matching features of the patient's plalate, jaw, and/or dentition formed in its palate facing side. In one embodiment, fixed aligner comprises bio-compatible material suitable for oral use as is known to those skilled in the art. In one embodiment, third fixed aligner1901comprises apertures1936that are formed in the third fixed aligner1901to guide insertion of second fasteners111into the hard palate. In one embodiment, apertures1936are formed along a peripheral notch1937formed in the third fixed aligner that is configured to receive first bodies100a-b. In one embodiment of use, after installation against a patient's soft palate, third fixed aligner1901is used to guide first bodies100a-band fasteners111into a position on either side of a palatine suture and such that fasteners111can be rotated into the hard palate until threads at their top become fixed in and against the pair of first bodies. In one embodiment, insertion of dentition portions of third fixed aligner111against dentition of a patient can be used so that movement of the first bodies100a-bwith respect to the maxilla is minimized during insertion of fasteners111. In one embodiment of use, third fixed aligner1901is to define a space/gap between the first bodies100a-band the palate. To achieve a desired space/gap, third fixed aligner1901can be manufactured with a thickness in the area around apertures1936according to a particular desired space/or gap, for example, with a space/gap between about 0.1 mm and about 3 mm. Third fixed aligner1901can be made from a relatively rigid, but frangible material, for example, biocompatible acrylic, resin, or polycarbonate. In one embodiment, third fixed aligner1901is provided with one or more thinned region1938that enable removal of the fixed aligner via subsequent breakage of the aligner along of the thinned region(s) so that the broken pieces of the aligner can be removed from around the fasteners and under the pair of first bodies100a-band so the aligner can be removed without removing or loosening fasteners111. Referring toFIGS.15a-c, there is seen a representation of another third fixed fastener. In one embodiment, a third fixed aligner2001is manufactured using techniques discussed above with reference to third aligner1901. In one embodiment, third fixed aligner2001comprises alignment features2117configured to receive a pair of first bodies2100a-b, and a plurality of apertures2119configured to receive a plurality of fasteners, including fasteners2116and fasteners2111. In one embodiment, the plurality of apertures2119comprise apertures that are configured with a spacing that match spacings of respective apertures2115in first fixed aligner2106and the first bodies2100a-b. In one embodiment of use, first bodies2100a-bare positioned against and/or in features2117on one side of third fixed aligner2001, first fixed aligner2106is positioned against an opposite side of the third fixed aligner2001, and fasteners2116are inserted in apertures2115, through apertures2119, and into apertures in the first bodies to join the first bodies and the first fixed aligner together so as to form an assembly where the third fixed aligner is sandwiched between the pair of first bodies and the first fixed aligner. In one embodiment of use, the assembly is subsequently positioned against the palate and a plurality of fasteners2111are used to secure the assembly to the palate. In one embodiment of use, third fixed aligner2001comprises a thickness T1in an area configured to receive the first bodies2100a-bin features2117, where the thickness T1is thicker than a thickness T2of the pair of first bodies2100a-b, and such that a palatal facing side of the first bodies2100a-bin an assembly mounted to the palate is spaced apart from the palate by distance determined by a difference between the thickness of the third fixed aligner2001and the thickness of the pair of first bodies, for example, a distance of about 0.1 mm and 3 mm. In one embodiment, third fixed aligner2001and first fixed aligner2106comprise apertures2139that are configured with dimension that allows the plurality of fasteners2111be received entirely therethrough and such that subsequently the second fixed aligner2106and the third fixed aligner2001can be removed via removal of fasteners2116while leaving the pair of first bodies2100a-bsecured to the hard palate via fasteners2111in a configuration that the pair of first bodies are spaced apart from the palate by a distance and such that an adjustable aligner150can be coupled thereto. In one embodiment, third fixed aligner2001is configured to fixate to a patient's dentition, and to be sandwiched between first bodies2100a-band fixed aligner2106so as to position the bodies against a particular location in a patient's mouth. The thickness of and counterbores formed in first bodies2100aact to further align fasteners2111to enable a precise mounting of first bodies2100a-babove the palate and of fasteners2111into the hard palate. Referring toFIGS.16a-d, there are seen representations of another skeletal anchorage device. In some embodiments, it may difficult to secure certain embodiments described above in a patient's mouth due to a “v” shaped, narrow, or constricted palate, where in palates of these and other shapes, the vertical orientation of the threadable second fasteners111with respect to the palate may be difficult to secure in place due to the limited flat surface area. In one embodiment a skeletal anchorage device comprises a pair of first bodies100c-d(seeFIG.16b-c). In one embodiment (seeFIG.16a), the pair of first bodies100c-deach comprise second apertures102that define longitudinal channels that are angled (instead of being parallel) with respect to longitudinal channels that define first apertures101. This allows the pair of first bodies100c-dto be secured to a pair of second bodies151a-bin a similar manner as described with other prior embodiments, but where the axis of threadable second fasteners111inserted within second apertures102of one of the pair of first bodies100c-dwill be oriented at an angle with respect to the longitudinal axis of second fasteners inserted in the other of the pair of first bodies. In one embodiment, extensions173may be provided to the first bodies100c-dto provide additional structural support for second apertures102. In one embodiment, the pair of first bodies100c-dwith the extensions173comprise a unitary element. In other embodiments, the first bodies100c-dand the extensions may be coupled together through various attachment means. It should also be noted that inserting the screws at an angle may allow for more surface contact in the bone than a vertical screw. Moreover, an angled screw can be designed to insert through the mid palatal suture in a different way than a vertical screw, which may be desirable) Although in the embodiments ofFIGS.16a-cthe first bodies are configured to mate with second bodies along extension portions173of a top surface that are not parallel to bottom surface of the first bodies, in other embodiments the extension portions can be eliminates such that top surfaces and bottom surfaces of first bodies are substantially flat and/or parallel to each other (seeFIG.16d). In one embodiment, as may be determined by a particular patient's palate shape and anatomy the angle of the longitudinal axis of second apertures102with respect to the longitudinal axis of first apertures101in each body100c-dmay comprise between about zero (0) and about ninety (90 degrees). In other embodiments, the angle of the longitudinal axis of second apertures102with respect to the longitudinal axis of first apertures101is between about one (1) and about sixty (60) degrees. In one embodiment, the angle of the longitudinal axis of second apertures102with respect to the longitudinal axis of second apertures in one of the pair of second bodies100c-dmay be the same as the angle in the second of the pair of first bodies100c-d. In one embodiment, the angle of the longitudinal axis of second apertures102with respect to the longitudinal axis of second apertures in one of the pair of second bodies100c-dmay be the different from that of the angle in the second of the pair of first bodies100c-d. Although the embodiments discussed and described above have so far been directed to devices and methods used to apply transverse forces to treat maxillary deficiencies, the present invention identifies that one or more of the embodiments can be used to apply forward protraction forces to treat maxillary deficiencies. In embodiments above, it was identified that a pair of second151a-bor third bodies170a-bcan be coupled to a pair of first bodies100a-b, where in one embodiment, apertures197in the pair of third bodies170a-bare configured to be coupled to a spring wire196(seeFIG.10b) that is used to maintain a lateral distance between palatine sutures of the maxilla. As seen in embodiments below, the second and third bodies can also be configured to comprise apertures that can be intraorally coupled to an externally worn appliance, for example an orthodontic face bow, that can be used to enable forward movement and growth to the maxilla. In one embodiment, the appliance transfers one or more extra-oral protraction force to bodies mounted intraorally to a patient's maxilla in a manner that does not cause downward forward directed movement and growth of the maxilla, or equivalently only forward growth, or a combination of forward and upward movement and growth. Referring toFIGS.17a-c, there are seen representations of an orthodontic device comprised of a pair of third bodies and an externally worn appliance coupled to the pair of bodies. In one embodiment (FIG.17abelow), a pair of third bodies2170a-bare coupled to a palate via a pair of intervening first bodies2100a-b(not shown as they are underneath third bodies2170a-binFIG.17a). In one embodiment, each of the pair of third bodies2170a-bis configured to mate with each free end of appliance2002(represented by2002a-d). In one embodiment, mating is achieved via insertion of free male ends of appliance into female apertures2197of the pair of third bodies. In embodiments, mating can be maintained via a fastener, an interference fit, snap fit, slip fit, and/or or other releasable coupling formed between the pair of third bodies2170a-band free ends of appliance2002. In some embodiments, apertures2197enable quick and simple coupling and removal of appliance2002to and from the pair of first bodies2100a-b. In some embodiments, appliance2002is manufactured from one or more stainless steel, ceramic, cobalt chrome or other sufficiently strong material. In another embodiment, a pair of second bodies2151a-bare coupled to a hard palate via intervening first bodies2100a-b. In one embodiment, each of the pair of second bodies2151a-bis configured to mate with each free end of an appliance2002. In embodiments, mating can be maintained via a fastener, interference fit, snap fit, slip fit, or releasable coupling formed between the pair of second bodies2150a-band the free ends of appliance2002. In one embodiment, mating is achieved via insertion of free male ends of appliance2002to into female apertures2197formed in the second bodies. Referring toFIG.18, there is seen a representation of a pair of first bodies coupled to an externally worn appliance. In one embodiment, rather than couple an appliance2002to second2151a-bor third bodies2170a-b, the appliance is coupled to a pair of first bodies2100a-bvia fasteners2198provided to or in the first bodies. In one embodiment, first bodies2100a-bcomprise apertures similar to apertures2197described above. Referring back toFIG.17a, in one embodiment, appliance2002comprises two first portions2002athat are configured in a shape that extends laterally away from each free end to behind each of a patient's most posterior teeth (for example, molars), where after extending past the posterior teeth, the two first portions2002aare configured to join to third portions2002cby bent portions2002b, where the third portions2002care configured in a shape that extends from the bent portions generally along and opposite outer surfaces of a patient's teeth and out the patient's mouth, where outside the patient's mouth, the two third portions2002are configured to be joined together, either in the form of an integral or non-integral fourth portion2002d, or directly. In another embodiment, instead of extending laterally behind distal teeth, first portions2002acan be configured in a shape that allows them to fit between spaces present between the teeth. In other embodiments, the shape of one or more portions of appliance2002an be customized to match a patient's particular geometry. Referring toFIGS.19a-b, there are seen other representations of an externally worn orthodontic appliance. In one embodiment, appliance2002comprises a fifth portion2002e. In one embodiment, the fifth portion is coupled to, and extends centrally from fourth portion2002din a generally orthogonal and upward direction relative to the fourth portion. In one embodiment, fifth portion2002eis coupled to fourth portion2002dvia a rigid connection, for example, via brazing, welding, or other fixed coupling mechanism know to those skilled in the art. In one embodiment, fifth portion2002eis configured with two branches that extend upward from the fourth portion2002dand that rejoin together above the fourth portion2002din a manner that an aperture is defined by and such that the two rejoined branches extend to a terminating end. In one embodiment, the fifth portion2002ecomprises at least one force application point2002nin the form of a hook, ring (seeFIG.19a), indentation (seeFIG.19b), or other attachment mechanism to which elastics or other external force applicators from externally worn protraction frames or devices can be coupled. In one embodiment, fifth portion2002eis configured such that it extends upward such that little or no interference occurs with a patient's nose during use. Referring toFIGS.20a-b, there is seen a representation of external forces applied to an externally worn appliance. As identified by the present inventors, when external protraction forces are coupled to an appliance, and by the appliance to a pair of bone anchors mounted to the maxilla, application of forward or forward and upward forces to the appliance may be used to achieve substantially only forward growth, or forward and upward growth, wherein such forces preferably do not generate or minimally generate rotational moments about the attachment points of the bone anchors to the maxilla. The present invention identifies that when forward, or forward and upward protraction forces are applied to an appliance that is coupled to a pair of bodies coupled to a maxilla at a hard palate location, forward or substantially forward movement and growth of the maxilla can also be achieved when rotational moments at the pair of first bodies2100a-bwhere they are coupled to the maxilla are eliminated or substantially minimized. The present invention identifies that rotational moments transferred to the pair of bodies and, thus, the maxilla can be substantially minimized or eliminated when extra-oral forces are applied to a appliance in a direction that passes through the force application points on the appliance (for example see points A, B, and/or C) and a pair of bodies (for example, see first bodies2100a-binFIG.20a) coupled to the maxilla (for example, the hard palate). In one embodiment, with reference to a standing patient whose skull face forward, and with 1588 gm of force applied to an appliance along an axis passing at an angle of 60 degrees with respect to the horizontal and through an application point “C” on the appliance and through a point “D” on a pair of first bodies, desired forward only growth and movement of a patient's maxillary complex can be achieved. Depending on a particular patient's skeletal geometry and/or a particular amount of desired movement or growth of a patient's maxilla, other forces, angles and other locations on the appliance are also within the scope of the invention as long the direction of force(s) applied to the appliance are aligned to a pair of bodies according to the embodiments described above. For example, as shown inFIG.20b, protraction forces can potentially be applied to a fifth portion2002eat other locations2002n, as long as the forces are applied in a direction that passes generally centrally through the pair of first bodies and the force application point on the appliance. Referring toFIGS.21a-b, there is seen another representation of an externally worn orthodontic appliance and its use. In one embodiment, each third portion2002cof appliance2002extends generally along and opposite outer surfaces of a patient's teeth and is formed of an intra-oral portion2002pand an intraoral/extra-oral portion2002qcoupled to intra-oral portion2002pby a releasable joint2002f, for example, via a releasable joint formed by one or more of hooks, rings, snap fits, slip fits, interference fits, and/or other similar interlockings formed at ends of the intra-oral and intraoral/extra-oral portions. In one embodiment, during intra-oral use of appliance2002, as needed or desired (for example, during periods when an external head gear and appliance may not be desired to be worn in public) intraoral/extra-oral portions can be decoupled from intra-oral portions via a releasable joint2002f. Although,FIGS.21a-brepresent an appliance joined at one joint2002fon each of its sides, it is understood that in other embodiments, an appliance could comprise more joints, and thus more releasable portions than are represented. Thus, when using pairs of first2100a-b, second2151a-bor third bodies2170a-bwith an orthodontic appliance2002, it identified that in addition to lateral expansion and growth of a maxilla, forward or a combination of forward and upward movement and growth of a patient's maxilla can also be achieved. In an embodiment where third bodies2170a-bare used, it is further identified that in addition to bilateral movement and growth, unilateral movement and growth of the maxilla can also be achieved. It is also identified that use of pairs of first2100a-b, second2151a-band third bodies2170a-bobviates the need to perform invasive surgical procedures such as those needed by other devices. It is further identified that aspects of the present invention are well suited for use of an externally worn appliance by a sleeping patient since it can be configured with shapes that span only above and across a patient's frontal facial anatomy and that only minimally interferes sleeping on the side. The preceding embodiments have been described in some detail to facilitate understanding, the described embodiments are to be considered illustrative and not limiting. It will be apparent to one of ordinary skill in the art that certain changes and modifications can be practiced within the scope of the appended claims. For example, one or more features from any embodiment may be combined with one or more features of any other embodiment without departing from the scope of the disclosure. Further, modifications, additions, or omissions may be made to any embodiment without departing from the scope of the disclosure. Additionally, other dimensions and other materials other than those disclosed can be used as long as they are compatible and sufficiently robust for human use. Also, although embodiments of the present invention are described to enable use without necessarily requiring coupling to dental or molar band, it should be understood that such use is not precluded and the present invention could, if desired, be adapted for use with such devices. Further, although embodiments of the present invention have been described with respect to use as a orthodontic device to treat orthodontic conditions, their use is much greater, for example as a medical device that can be used to treat non-obese obstructive sleep apnea caused by maxillary hypoplasia, or for use with other surgical procedures capable of being performed by a craniomaxillofacial surgeon, which procedure could be covered by medical insurance rather than just by dental insurance.

11857231

DETAILED DESCRIPTION InFIG.1, a bone compression device10is provided having a bone plate12with a body14for being secured to bones with bone anchors, such as bone screws16. The bone plate12is made entirely or partially of a shape-retentive material that permits elastic deformation of the bone plate12and resiliently biases the bone screws16and bones connected thereto together once the bone plate12has been implanted on the bones. In one form, the bone plate12is made of nitinol having superelastic properties that permits the bone plate12to deform elastically as the bone plate12is flexed during implantation of the bone plate12, as discussed in greater detail below. Once the bone plate12is implanted in a flexed configuration thereof, the bone plate12acts as a spring and applies constant compression to the bones until the elastically deformed bone plate12returns toward its initial, unflexed configuration. This is an improvement over some prior compression bone plates that are plastically deformed to compress bones. In these bone plates, there may be spring back within the bone plate after implantation of the bone plate which reduces the compression applied to the bones. As another example, the bone plate12may be made from a shape memory material, such as shape memory nitinol, which would compress the bones by changing shape in situ from a flexed configuration to an unflexed configuration in response to the internal temperature of the patient. The bone plate12has an initial, unflexed configuration where an intermediate portion20of the bone plate12is curved or bent, as shown inFIG.2. With reference toFIGS.7,11, and12, the bone plate12may be flexed using an instrument15that includes a pair of manipulators17,19. The manipulators17,19are connected to the bone plate12and squeezed together toward an installation orientation as shown inFIG.12, which bends the bone plate12to the flexed configuration wherein the intermediate portion20is substantially straight. This loads the intermediate portion20and stores potential energy in the bone plate12in a manner similar to compressing a spring. A restraint190(seeFIG.14) may be connected to the manipulators17,19to hold the manipulators17,19in the installation orientation which, in turn, maintains the bone plate12in the flexed configuration. Next, the assembled manipulators17,19and restraint190are manipulated to position the bone plate12in the flexed configuration thereof against bones13,15, as shown inFIG.17. The bone screws16are advanced through the manipulators17,19and driven into throughbores22,24of the bone plate12to secure the bone plate12to the bones13,15. With the bone plate12secured to the bones13,15in the flexed configuration, the bone plate12resiliently biases against the bone screws12as the bone plate12rebounds or returns toward its unflexed configuration and the intermediate portion20returns in direction30toward its curved, unflexed shape32, as shown by dashed lines inFIG.23. Thus, the bone plate12urges the bone screws16together as the bone plate12rebounds toward its unflexed configuration which compresses the bones13,15together to heal a cut or break280. The length of the bone plate12may be selected so that the bone plate12does not completely return to its unflexed configuration after being secured to the bones13,15so that the bone plate12continues to continuously apply compression to the bones13,15. Further, the intermediate portion20may flex as needed to accommodate subsidence or movement of the bones13,15post-surgery while continuing to compress the bones13,15together. With reference toFIG.1, the bone plate12has bone anchor receiving portions, such as lobes40,42, which include the through bores22,24. In one form, the bone compression device10includes retention mechanisms44to resist back-out of head portions46of bone screws16from the lobes40,42. In addition to resisting back-out of the bone screw head portions46, the screw retention mechanisms44may also fix the bone screw head portions46to the bone plate lobes40,42. By fixing the bone screw head portions46to the bone plate lobes40,42, the bone screws16and bone plate lobes40,42form a rigid construct with the bones13,15while the intermediate portion20compresses the bones. This rigid construct permits a single bone plate12and two screws16to be used to stabilize bones where, in prior approaches, a pair of nitinol staples would need to be used and would involve the inefficiencies associated therewith. In one form, the screw retention mechanisms44includes cooperating threads on the bone screw head portion46and the lobes40,42. In another form, the screw retention mechanisms44may include an expandable bone screw head portion46and an actuator for expanding the head portion46into engagement with the surfaces of the through bores22,24, for example. Another advantage of the bone compression device10is that a surgical kit of several bone compression devices10may be provided with fewer components than a corresponding kit of nitinol staples. The kit of bone compression devices10would include a plurality of bone plates12having different lengths, a plurality of bone screws16having different lengths, the manipulators17,19, and the restraint190. The kit of bone compression devices10could have fewer components than the nitinol staple kit because the different length screws16in the kit could be used with any of the lengths of bone plate12in the kit. Thus, the kit of bone compression devices10would include one set of bone screws16of different lengths, rather than a set of bone screws16of different lengths for each bone plate12. This is an improvement over a corresponding kit of nitinol staples which would include, for each staple bridge length, a set of staples with different leg lengths. The surgical kit may be provided with one length of manipulators17,19that can be used with the bonne plates12of different lengths or may provided with a plurality of pairs of manipulators17,19having different lengths. Further, the surgical kit may be provided with one or more of the restraints190. If one restraint190is provided, the restraint190may be adjustable to fix the manipulators17,19at different distances apart. With reference toFIG.2, the bone plate12is shown in an initial, unflexed configuration with the intermediate portion20having a non-linear, curved shape. The curved shape of the intermediate portion20orients center lines50,52of the through bores22,24to extend at an angle53relative to each other. The lobes40,42each have an instrument receiving portion54including a notched profile56with a lip58and a depending flat60. The lip58has a lower surface62that is lifted upward by a lip engaging portion66(seeFIG.5) of the associated manipulator17,19, as discussed in greater detail below. With reference toFIGS.3and5, the lobes40,42of the bone plate are each configured to form a mating, non-rotatable fit with a distal lobe engaging portion72of one of the manipulators17,19. Specifically, the lobe42has a rounded outer surface80that fits within a rounded inner surface82of the lobe engaging portion72of the manipulator19. The lobes40,42are sized to fit within openings74of the manipulators17,19and the flats60of the lobes40,42each abut a flat76of the associated manipulator17,19. The abutting flats60,76of the lobes40,42and manipulators17,19resist turning of the lobes40,42within the lobe engaging portions72as shown inFIG.9. With continued reference toFIGS.3and5, the manipulator19has a notch84sized to receive a section of the intermediate portion20of the bone plate12as the manipulator19is advanced onto the lobe42. The manipulator19has a fulcrum88for engaging the bone plate12as the manipulator19is pivoted toward the manipulator17to bend the bone plate12as discussed in greater detail below. The fulcrum88includes a surface90that rests upon an upper surface92of the bone plate12, as shown inFIG.8. Further, the notch84includes walls160,162arranged to abut sides164,166of the intermediate portion20and resist rotational movement between the lobe24and the manipulator19. Returning toFIG.5, the manipulator19has an aperture100sized to receive the lip58of the lobe42. The aperture100has a width102larger than a width104(seeFIG.3) of the lip58. Turning toFIGS.8and18, the lip58of the lobe42extends over and is supported on an upper surface150of the lip engaging portion66with the lip58positioned in the aperture100such that pivoting of the manipulator19in direction132tightly engages the lip lower surface62and the upper surface150(seeFIG.8). With reference toFIG.6, the manipulator19has a cannula110with a center112and a wall114extending about the cannula110. As noted above, the lip engaging portion66of the manipulator19engages the lip lower surface62of the lobe42and the surface90of the manipulator19seats on the upper surface92of the bone plate12with the manipulator19connected to the lobe42. To provide leverage to bend the bone plate12, the manipulators17,19have a distance116between the lip engaging portion66and the surface90of each manipulators17,19. In this manner, pivoting the manipulators17,19in directions130,132as shown inFIGS.11and12tends to pull upwardly on the lip58and pushes downwardly on the upper surface92of the bone plate12which straightens out the bone plate intermediate portion20. Additionally, the manipulators17,19have a length136that provides additional leverage for bending the bone plate12as shown inFIG.4. With reference toFIGS.7-23, a method of applying compression to the bones13,15using the bone plate12is shown. Initially, the lobe engaging portions72of the manipulators17,19are connected to the lobes40,42of the bone plate12. With reference toFIG.7, the manipulator19is maneuvered in direction140to position the lip engaging portion66in the notched profile56of the lobe42below the lip58. With the lip engaging portion66engaged with the underside of the lip58, the manipulator19is then pivoted in direction142which shifts the notch84downward onto the intermediate portion20of the bone plate12and seats the lobe engaging portion72on the lobe42. With reference toFIG.8, the manipulator19is shown after pivoting in direction142such that the upper surface150of the lip engaging portion66is engaged with the lower surface62of the lip58, the flat76of the manipulator19is engaged with the flat60of the lobe42, and the surface90of the manipulator19is engaged with the upper surface92of the bone plate12. The lip engaging portion66engages the bone plate12at one side of the lobe42and the notch84engages the intermediate portion20at the opposite side of the lobe42. This engagement resists lateral movement between the lobe42and the manipulator19in directions152,154even as the manipulator19is pivoted to bend the bone plate12. Further, this engagement maintains a coaxial alignment of a center line of the lobe through bore24and a center line of the manipulator cannula110. The aligned center lines of the through bore24and cannula110will be referred to with combined reference numeral156. The manipulator17is then connected to the lobe40in a similar manner and establishes a coaxially aligned center line158of the through bore22of the lobe40and the cannula110of the manipulator17. With reference toFIGS.10and11, the manipulators17,19are shown connected to the lobes40,42of the bone plate12. At this point, the bone plate12is in the initial, unflexed configuration and the intermediate portion20of the bone plate12has a curved shape. With the bone plate12in the unflexed configuration, the center lines156,158are oriented at an angle170that may be the same or substantially the same as the angle53between the centerlines50,52of the bone plate throughbores22,24with the bone plate12in the unflexed configuration (seeFIG.2). Next, the manipulators17,19are pivoted toward each other in directions130,132such as by a user squeezing the manipulators17,19together, into an installation orientation as shown inFIG.12. With the manipulators17,19in the installation orientation, the centerlines156,158may be substantially parallel to each other, as shown inFIG.12. ComparingFIGS.11and12, pivoting the manipulators17,19toward each other flexes the bone plate12and bends the intermediate portion20into a straight configuration. With the bone plate12in the flexed configuration ofFIG.12, the bone plate12is generally planar which is in contrast to the bent configuration of the bone plate12shown inFIG.2. It will be appreciated that the bone plate12may have a flexed configuration for some procedures where the bone plate12is partially flexed and the intermediate portion20is only partially straightened. Even when the intermediate portion20is only partially straightened, the elastic properties of the bone plate12will still apply a constant, compressive force against the bones13,15once the bone plate12has been secured to the bones13,15. To maintain the manipulators17,19in the installation orientation and keep the bone plate12in the flexed configuration, a restraint190may be connected to proximal end portions192,194of the manipulators17,19. As shown inFIGS.14and15, the restraint190has collars198,200and a link portion210connecting the collars198,200. The restraint190is connected to the manipulators17,19by advancing the restraint190in direction210so that the collars198,200fit over necks206,208of the manipulators17,19and rest against shoulders212,214of the manipulators17,19. The restraint190resists pivoting of the manipulators17,19in directions220,222away from the installation orientation, as shown inFIG.15. The manipulators17,19and restraint190may be made materials, such as metals or polymers, sufficiently rigid to resist the resilient bending of the bone plate12back toward its initial, unflexed configuration. For example, the manipulators17,19may be made of stainless steel and the restraint190may be made from carbon fiber polyether ether ketone (PEEK). Further, the manipulators17,19and restraint190may be disposable or reusable. With reference toFIG.16, the collars198,200may fit around the exteriors of the necks206,208of the manipulators17,19which permits the cannulas110of the manipulators17,19to be unobstructed with the restraint190connected to the manipulators17,19. The unobstructed cannulas110permit access to the through bores22,24of the lobes40,42through the cannulas110. With reference toFIGS.17and18, the restraint190maintains the manipulators17,19and bone plate12in an assembled configuration and permits one-handed handling of the assembly of the bone plate12, manipulators17,19, and restraint190. This assembly of the restraint190, manipulators17,19and bone plate12can be readily maneuvered in direction230into position on the bones13,15. As shown inFIG.18, the intermediate portion20of the bone plate12is in its generally straight or flat configuration due to the restraint190continuing to resist pivoting of the manipulators17,19away from their installation orientation. As shown inFIG.18, the manipulators17,19have been used to position the bone plate12on the bones13,15such that the through bores22,24are each positioned over one of the bones13,15. Due to the elastic properties of the bone plate12, the intermediate portion20biases the lobes40,42back toward their unflexed orientations (seeFIG.2). The engagement of the notches84and lip engaging portions66of the manipulators17,19resist the lobes40,42returning to the unflexed orientations which causes the intermediate portion20to press upwardly against the surface90of the manipulators17,19and the lips58of the lobes40,42to press downwardly against the lip engaging portion66of the manipulators17,19. With reference toFIGS.19and20, an instrument, such as a screw driver240, has a shaft242with a bone screw16connected thereto. The screw driver240and bone screw16are advanced in direction244into the cannula110of manipulator19to advance a shank portion246of the bone screw16into the through bore24of the lobe42and drive the shank portion246into the bone15. The screw driver240continues to drive the bone screw16into the bone15until the head portion46of the bone screw16seats within the through bore24of the lobe42, as shown inFIG.21. This process is repeated to drive the other bone screw16into the through bore22of the lobe40so that both lobes40,42are secured to the bones13,15as shown inFIG.22. Once the bone plate12in the flexed configuration has been secured to the bones13,15the restraint190is removed in direction271to draw the collars198,200off of the necks206,208as shown inFIG.22. The bone plate engaging members17,19are pivoted in directions270,272to lift the notches84of the manipulators17,19off of the intermediate portion20of the bone plate12. Next, the manipulators are shifted outwardly in directions274,276in order to unhook the lip engaging portions66from below the lips58of the lobes40,42. With reference toFIG.23, the bone plate12in the flexed configuration is shown secured to the bones13,15. The bone screws16have been driven into the bones13,15to secure the lobes40,42against the bones13,15. Due to the elastic properties of the bone plate12, the intermediate portion20returns toward its unflexed configuration32. As the intermediate portion20bends upwardly from the bones13,15, the bone plate12applies tension to the bone screws16and compresses the bones13,15together. In another approach, the bone plate12may be made of a shape memory nitinol that shifts in situ from a flexed, installation configuration to an unflexed, compression configuration in response to the temperature of the patient. The bone plate12may be chilled, such as in a saline solution, mechanically forced into a straightened configuration, and implanted in the straightened configuration. As the temperature of the bone plate12raises to the internal temperature of the patient, the bone plate12will return to its original shape and compress the bones13,15. With reference toFIG.24, a bone compression device300is provided having a bone plate302that flexes within the thickness of the bone plate302to apply compression to bones. The bone plate302has a body304with lobes306,308and an intermediate portion310connecting the lobes306,308. In the unflexed configuration of the bone plate302, the intermediate portion310is curved or bent and extends between planes defined by upper and lower surfaces311,313of the lobes306,308. To flex the bone plate302to a flexed configuration, an instrument319is provided including manipulators320,322that each have a releasable connection324to the bone plate302. The releasable connection324includes a recess326of the bone plate302and a complimentary projection330of the associated manipulator320,322configured to form an interlocking, rigid engagement with the recesses326. With reference toFIG.25, the bone plate is shown in the initial, unflexed configuration. With the manipulators320,322connected to the bone plate302, longitudinal axis340,342of the manipulators320,322extend an angle344to one another. Next, handle portions350,352of the manipulators320,322are grasped and pressed toward one another in directions354,356from an initial orientation to an installation orientation. Because the manipulators320,322are connected to the lobes306,308, pressing the manipulator handle portions350,352together deflects the intermediate portion310from the initial, curved configuration as shown inFIG.24to a flexed, straightened configuration as shown inFIG.26. As the bone plate302flexes between the unflexed and flexed configurations, the intermediate portion310remains between the planes defined by the upper and lower surfaces311,313of the lobes306,308. With the bone plate302in the flexed configuration, a user may hold the manipulators320,322in the installation orientation and keep the bone plate302in the flexed configuration with one hand, e.g., between a thumb and an index finger. With reference toFIGS.27and28, the flexed bone plate302has been positioned on bones (not shown) and bone screws360are advanced in direction362into through bores364of the lobes306,308. Once the bone plate302has been secured to bones, the lobes306,308may turn slightly about a bone screw head portion364as the intermediate portion310bends back toward its curved, unflexed configuration and compresses the bones together via the bone screws360. To accommodate this slight turning of the lobes306,308about the head portions364, the head portions360may have a non-threaded outer surface370. If desired, screw retention mechanisms may be provided to resist backout of the bone screws360from the through bores364while permitting this turning of the lobes306,308about the head portion364. For example, the lobes306,308may each have a lip extending about the through bore364that deflects out of the way of the bone screw306as the bone screw306is advanced into the through bore364and then snaps back over the head portion364once the head portion364is seated within the through bore364. With reference toFIG.29, once the bone plate302has been secured to the bones via the bone screws360, the manipulators320,322may be disconnected from the bone plate302. For example, the projections330may be slid in direction380out of the recesses326. At this point, the flexed intermediate portion310biases against the bone screws360and compresses the bone screws360and bones connected thereto together as the intermediate portion returns toward its initial, unflexed configuration. As the intermediate portion310shifts from its straightened toward its curved configuration, the intermediate portion310travels along the outer surfaces of the bones rather than away from the outer surfaces of the bones as does the intermediate portion20of the bone plate12(seeFIG.23). With reference toFIG.30, a bone compression device400is provided having a bone plate402that is similar in many respects to the bone plate302as discussed above. However, the bone plate402has an integrated installation instrument403with manipulators404,406that may be used to flex the bone plate402and then be removed from the bone plate402after installation of the bone plate402onto bones. In one form, the manipulators404,406are integrally formed with a body408of the bone plate402. As used herein, the term “integral” is intended to refer to being formed as one piece with another part. With reference toFIG.31, the manipulator404is connected to the body408at a frangible portion410. To deflect the bone plate402from an initial, unflexed configuration to a flexed, installation configuration, a user grasps handle portions412of the manipulators404,406and squeezes the handle portions412together generally in direction414. This pivots the manipulator404about the frangible portion410in direction420and brings a surface422of the manipulator404into contact with a surface424of the body408. Stated differently, pivoting the manipulator404in direction420closes a gap426between the surfaces422,424with a distance428between the surfaces422,424, decreasing as the manipulator404pivots in direction420. With the surfaces422,424abutting, continued squeezing of the handle portions412together moves the lobes408in directions430and straightens an intermediate portion432. Once the bone plate402has been installed a user may bend, cut, or otherwise separate the manipulators404,406from the bone plate body408at the frangible portions410. With reference toFIGS.32, and33, a bone compression device500is provided having a resilient body502connecting bone screws504,506. The resilient body502includes end portions508,510secured to the bone screws504,506and an intermediate spring portion512configured to apply a compressive force to the bones connected to the bone screws504,506. The bone screws504,506have blind bores530that receive the end portions508,510of the resilient body502. The bores530each have an upper portion with a hex drive configuration to accommodate a hex driver for driving the bone screws into504,506into bone. With reference toFIG.33, a top plan view of the body502is provided showing the body502in an unflexed configuration. The body502has straight portions516,518,520and curved portions522,524connecting the straight portions516,518,520. To flex the body502, the end portions508,510are moved apart from each other in directions521,523. This causes the elbow portions522,524to elastically flex to a more open configuration as shown inFIG.34. Further, one or more of the straight portions516,518,520may elastically deform in the lengthwise direction. To apply compression to bones, the bone screws504,506are driven into the bones and the end portions508,510of the body502are moved apart from each other to shift the body502to the flexed configuration thereof as shown inFIG.34. The end portions508,510are held in their spaced orientation to keep the body502flexed and the end portions508,510are then advanced into the bores530of the bone screws504,506previously driven into the bones. The resilient body502biases against the bone screws504,506in directions534,536as the body502returns toward its unflexed configuration and compresses the bones. With reference toFIG.35, the bone compression device500includes a retention mechanism550for maintaining the end portions508,510in the bores530of the bone screws504,506. In one approach, the retention mechanism550includes a leading end portion552of the resilient body end portion508. The leading end portion552has a cam surface554and an enlarged portion556that snaps past a retention portion558of the bone screw504. More specifically, the retention portion558includes an annular collar564having an upper surface560and a lower surface562. Advancing the leading end portion552in direction570into the bore530engages the cam surface554with the upper surface560of the collar564. Continued advancing of the leading end portion552in direction570deflects the collar564and permits the enlarged portion556to snap past the collar564. With the leading end portion552advanced past the collar564, an upper surface574of the leading end portion552is arranged to abut the lower surface562of the retention portion558and resist back out of the leading end portion552. In one approach, the leading end portion508has a smooth, volcano-shaped neck portion580spaced from the collar564with the leading end portion552captured in the bore530by the collar564. The neck portion580permits the end portion508to turn within the bore530after installation of the bone compression device500which accommodates turning of the straight portion520in direction582(seeFIG.34) relative to the bone screw504as the resilient body502returns toward its unflexed configuration. The resilient body end portion508and bone screw504thereby form a pivot connection therebetween that permits reconfiguring of the resilient body502back toward its unflexed configuration while maintaining the end portion508securely connected to the bone screw5034. With reference toFIG.36, a bone compression device600is provided that is similar in many respects to the bone compression device500. The bone compression device600includes a resilient body602having end portions604,606that are configured to be secured to bone screws608,610and a spring portion612intermediate the end portions604,606. One difference between the resilient body602and the resilient body502is that the resilient body602has straight legs614,616connecting the end portions604,606, and the spring portion612. The straight legs614,616reduce turning of the end portions604,606relative to the bone screws608,610as the resilient body602returns toward its unflexed configuration. The straight legs614,616reduce turning of the end portions604,606relative to the bone screws608,610because elbow portions620,622of the spring portion612can flex and open as the resilient body602shifts toward its flexed configuration while the straight legs614,616remain generally aligned along an axis630. The bone compression device600may have retention mechanisms that rigidly fix the resilient body602to the bone screws608,610since the end portions608,610generally do not turn relative to the bone screws608,610as the resilient body602returns toward its unflexed configuration. The bone compression devices discussed above may be used in a variety of applications, such as hand and foot bone fragment and osteotomy fixation and joint arthrodesis, fixation of proximal tibial metaphysis osteotomy, and adjunctive fixation of small bone fragments. The bone compression devices may be used with bones such as the femur, humerus, clavicle, sternum, ribs, and pelvis. Those skilled in the art will recognize that a wide variety of modifications, alterations, and combinations can be made with respect to the above-described embodiments without departing from the spirit and scope of the invention, and that much modifications, alterations, and combinations are to be viewed as being within the ambit of the inventive concept.

11857232

DETAILED DESCRIPTION OF THE INVENTION The present invention will be discussed hereinafter in detail in terms of various exemplary embodiments according to the present invention with reference to the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be obvious, however, to those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known structures are not shown in detail in order to avoid unnecessary obscuring of the present invention. Thus, all the implementations described below are exemplary implementations provided to enable persons skilled in the art to make or use the embodiments of the disclosure and are not intended to limit the scope of the disclosure, which is defined by the claims. As used herein, the word “exemplary” or “illustrative” means “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” or “illustrative” is not necessarily to be construed as preferred or advantageous over other implementations. Moreover, in the present description, the terms “upper”, “lower”, “left”, “rear”, “right”, “front”, “vertical”, “horizontal”, and derivatives thereof shall relate to the invention as oriented inFIG.1. The following description references systems, methods, and apparatuses for use in femoral cerclage fixation. However, those possessing an ordinary level of skill in the relevant art will appreciate that fixation of other bones are suitable for use with the foregoing systems, methods, and apparatuses. Likewise, the various figures, steps, procedures, and work-flows are presented only as an example and in no way limit the systems, methods or apparatuses described to performing their respective tasks or outcomes in different time-frames or orders. The teachings of the present invention may be applied to cerclage related to any bone. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary, or the following detailed description. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless expressly stated otherwise. The various embodiments described herein provide for systems, apparatuses, devices, and methods for fracture fixation. The various figures and description may refer to femoral fracture fixation. However one having ordinary skill in the art will understand that that the following systems, apparatuses, devices, and methods for fracture fixation may be used with specific femoral fractures, such as periprosthetic Vancouver Grade B and distal femoral fractures, or fractures to other bones such as greater trochanter fractures; tibial distal, proximal, and mid shaft fractures; humeral head fractures; fibula fractures; olecranon fractures; and other bones with fractures, osteotomies, or deformities needing compressive and/or corrective forces. Referring to the drawings, wherein like reference numerals are used to indicate like or analogous components throughout the several views, and with particular reference toFIGS.1-2,7-10, and15-19, a fracture fixation system100is affixed to a bone or femur109, with the parts of femur109on opposite sides of a fracture110having been aligned. Fracture fixation system100has a medial plate101, longitudinally aligned on a medial surface142of femur109and a lateral plate102, longitudinally aligned on the lateral surface144of femur109. Medial plate101and lateral plate102are depicted on opposite sides of femur109and connected with a binding or a cerclage wire108, with fracture110being intermediate to medial plate101and lateral plate102. Medial plate101may be, for example, a cerclage adjunct device having an elongated plate, with a lateral wire slot or bore103, and having a lateral curvature approximating a circumferential curvature of medial surface142of femur109. Lateral plate102may also have a curvature, for example, approximating a circumferential curvature of a lateral surface of femur109. Lateral plate102may be, for example, further connect to femur109with a bone screw111inserted through lateral plate102and into femur109, with bone screw111positioned inferior to fracture110. Bone screw111may for example, extend through lateral plate102and through medial surface142of femur109. With continued reference toFIGS.1-2,7-10, and15-19, lateral plate102further has a first section125, a second section124, a top side122, a bottom side123, a first side126, and a second side127. First section125may be, for example, connected to medial plate101and around fracture110with cerclage wire108. First section125has a set screw120received in threaded opening, cerclage wire bore or cerclage wire entry hole115, a wire exit hole114, a post hole130, and a wire attachment undercut or a tethering recess104. Second section124extends longitudinally away from first section125distal to a femur head119. Second section124may have, for example, a plurality of holes112through which a plurality of bone screws (e.g., multiple instances of bone screw111) may be inserted into femur109. With reference toFIGS.3-6and20, a drum210has a threaded connection206between a lower end203with a threaded opening205, engaged with an upper end or driving end201with threading204. Driving end201is depicted as having a screw head209, which may, for example, be square shaped and engageable with a nut driver or other tool for driving drum210. Driving end201may be rotated, for example, in a clockwise direction by hand or such a nut driver. Rotation of driving end201, may, for example, close driving end201and lower end203together. Cerclage wire108may be threaded through a cross hole208such that rotating driving end201may, for example, clamp cerclage wire108between lower end203and driving end201, keeping cerclage wire108stationary. Drum210may further have, for example, a bushing202, positioned between lower end203and driving end201such that rotating driving end201exerts linear pressure onto cerclage wire108without translating rotational motion. Such linear pressure may be, for example, used to maintain cerclage wire108position in cross hole208due to friction where cerclage wire108contacts and is located between bushing202and lower end203. Continued rotation of driving end may, for example, rotate drum210with cerclage wire108extended through hole208thereby causing cerclage wire108to be wound around drum210, thereby causing tension in cerclage wire108to be increased. During rotation of drum210, linear pressure is maintained by bushing202on cerclage wire108, without adding rotation pressure to cerclage wire108within drum210. Adjusting and maintaining tension may aid in holding bone fragments in place during a surgical procedure and after when subjected to anatomic loading. As depicted inFIGS.21-25, with reference to first section125of lateral plate102, cerclage wire entry hole115is depicted positioned on a first side126and wire exit hole114is positioned on top side122. Wire entry hole115and wire exit hole114extend to meet through lateral plate first section125, creating an oblique hole or tunnel therebetween. Set screw120is depicted inset into top side122, intersecting with the bore between wire entry hole115and wire exit hole114. Cerclage wire108is depicted with a cerclage wire head or a cerclage wire first end118and a free end116. Tethering recess104may be, for example, a slot or opening extending from bottom side123to second side127, configured (e.g., shaped and dimensioned) to capture cerclage wire head118, when cerclage wire108is under tension. Post hole130extends from top side125towards bottom side124and is configured (e.g., shaped and dimensioned) to accept insertion of post207of drum210. With reference toFIGS.1-25, a method of fracture fixation includes aligning opposing sides of fracture110and affixing lateral plate102to lateral surface144. Cerclage wire first end118may be inserted into tethering recess104. Free end116may be, for example, inserted through lateral wire slot103of medial plate101, with medial plate101placed onto medial surface142. Free end116may, for example, continue around femur109and be inserted into entry hole115, exiting through exit hole114. Drum210, may, for example, be engaged with lateral plate102, with post207inserted into post hole130. Free end116may be inserted through cross hole208and rotating upper drive end201imparts a clamping, linear force onto cerclage wire108, without rotational motion. Cerclage wire108may then be tensioned by winding free end116of cerclage wire108around drum210and turning upper drive201and rotating drum210to further wind cerclage wire108. Such rotation may impart tension to cerclage wire108and set cerclage wire118into tethering recess104. Once the desired tension is reached, set screw120may be tightened (e.g., into a threaded hole in lateral plate102) to capture or clamp cerclage wire108within the hole extending from entry hole115to exit hole114. To maintain tension on cerclage wire108, free end116thereof may be, for example, placed in a crimp (not shown) or holder on or adjacent to lateral plate102. With reference toFIGS.1-25, a plurality of cerclage wires (e.g., multiple instances of cerclage wire108) may, for example, be used to engage medial plate101and lateral plate102. A plurality of bone screws (e.g., multiple instances of bone screw111) may, for example, be inserted into plurality of bone screw holes112to affix lateral plate102to femur109. As depicted, medial plate101may have, for example, a plurality of lateral wire slots (e.g., multiple instances of wire slot103). Medial plate101, may be, for example, a two wire cerclage adjunct device or a three wire cerclage adjunct device. As further depicted, lateral plate102may have, for example, a plurality of set screws (e.g., multiple instances of set screw120), a plurality of cerclage entry holes (e.g., multiple instances of cerclage wire entry hole115), a plurality of wire exit holes (e.g., multiple instances of wire exit hole114), a plurality of post holes (e.g., multiple instances of post hole130), and a plurality of tethering recesses (e.g., multiple instances of tethering recess104). In other embodiments of fracture fixation system100, may have, for example, at least two plates of the kind described by medial plate101and/or lateral plate102. Aspects of the invention described herein include bone fixation of fractures to promote bone fusion in femur109. Those same aspects also include bone fixation of fracture to promote bone fusion in a femur having a hip replacements stem (not shown) inserted into femur109. While several aspects of the present invention have been described and depicted herein, alternative aspects may be effected by those skilled in the art to accomplish the same objectives. Accordingly, it is intended to cover all such alternative aspects as fall within the true spirit and scope of the invention.

11857233

DETAILED DESCRIPTION The exemplary embodiments of a surgical system and related methods of use disclosed are discussed in terms of medical devices for the treatment of musculoskeletal disorders and more particularly, in terms of a spinal implant having a structurally optimized internal structure to enhance the mechanical properties of the bone screw. In some embodiments, the spinal implant system of the present disclosure comprises a bone screw having internal features to structurally optimize the mechanical properties of the bone screw that combines a manufacturing method, such as, for example, one or more traditional manufacturing features and materials and a manufacturing method, such as, for example, one or more additive manufacturing features and materials. In some embodiments, the bone screw is configured with internal features, such as, for example, various forms and/or patterns. In some embodiments, the internal features may be homogeneous. In some embodiments, the internal features are configured to optimize bone screw function by increasing bone screw rigidity and/or increasing bone screw strength. In some embodiments, the internal features are configured to provide deflection in selected areas of the bone screw. In some embodiments, the spinal implant system of the present disclosure comprises a bone screw having a solid core that includes a varied configuration to optimize bone screw function. In some embodiments, the features of the bone screw can be created and/or altered through additive manufacturing. In some embodiments, the features can be manufactured to minimize material usage. In some embodiments, the configuration of the solid core is configured to provide deflection in selected areas of the bone screw. In some embodiments, the bone screw includes features, such as, for example, struts, braces and/or honeycomb patterns of material within the body of the bone screw. In some embodiments, the features include porous and/or trabecular material. In some embodiments, the bone screw includes an internal solid strut configured to reinforce a load bearing portion of the bone screw. In some embodiments, the spinal implant system of the present disclosure is configured to enhance fixation of bone screws with bone. In some embodiments, the spinal implant system of the present disclosure includes a spinal implant configured for engagement with cortical bone and cancellous bone within the vertebra. In some embodiments, the spinal implant system of the present disclosure is configured to resist and/or prevent toggle on a bone screw when the bone screw is engaged with dense cortical bone and a less dense cancellous bone resulting from a load on the bone screw. In some embodiments, the spinal implant system of the present disclosure is configured to resist and/or prevent loosening of the bone screw from the cortical bone and in some instances, pull out from the vertebra. In some embodiments, the spinal implant system of the present disclosure is configured to facilitate bone through-growth to provide for an improved bone attachment to the bone screw. In some embodiments, the bone screw is anchored in the bone thereby reducing pull out. In some embodiments, the spinal implant system comprises a spinal implant having a hybrid configuration that combines a manufacturing method, such as, for example, one or more traditional manufacturing features and materials and a manufacturing method, such as, for example, one or more additive manufacturing features and materials. In some embodiments, additive manufacturing includes 3-D printing. In some embodiments, additive manufacturing includes fused deposition modeling, selective laser sintering, direct metal laser sintering, selective laser melting, electron beam melting, layered object manufacturing and stereolithography. In some embodiments, additive manufacturing includes rapid prototyping, desktop manufacturing, direct manufacturing, direct digital manufacturing, digital fabrication, instant manufacturing and on-demand manufacturing. In some embodiments, the spinal implant system comprises a spinal implant being manufactured by a fully additive process and grown or otherwise printed. In some embodiments, the spinal implant system of the present disclosure comprises a spinal implant, such as, for example, a bone screw manufactured by combining traditional manufacturing methods and additive manufacturing methods. In some embodiments, the bone screw is manufactured by applying additive manufacturing material in areas where the bone screw can benefit from materials and properties of additive manufacturing. In some embodiments, traditional materials are utilized where the benefits of these materials, such as physical properties and cost, are superior to those resulting from additive manufacturing features and materials. In some embodiments, the spinal implants, surgical instruments and/or medical devices of the present disclosure may be employed to treat spinal disorders such as, for example, degenerative disc disease, disc herniation, osteoporosis, spondylolisthesis, stenosis, scoliosis and other curvature abnormalities, kyphosis, tumor and fractures. In some embodiments, the spinal implants, surgical instruments and/or medical devices of the present disclosure may be employed with other osteal and bone related applications, including those associated with diagnostics and therapeutics. In some embodiments, the spinal implants, surgical instruments and/or medical devices of the present disclosure may be alternatively employed in a surgical treatment with a patient in a prone or supine position, and/or employ various surgical approaches to the spine, including anterior, posterior, posterior mid-line, lateral, postero-lateral, and/or antero-lateral approaches, and in other body regions such as maxillofacial and extremities. The spinal implants, surgical instruments and/or medical devices of the present disclosure may also be alternatively employed with procedures for treating the lumbar, cervical, thoracic, sacral and pelvic regions of a spinal column. The spinal implants, surgical instruments and/or medical devices of the present disclosure may also be used on animals, bone models and other non-living substrates, such as, for example, in training, testing and demonstration. The present disclosure may be understood more readily by reference to the following detailed description of the embodiments taken in connection with the accompanying drawing figures, which form a part of this disclosure. It is to be understood that this application is not limited to the specific devices, methods, conditions or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting. In some embodiments, as used in the specification and including the appended claims, the singular forms “a,” “an,” and “the” include the plural, and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” or “approximately” one particular value and/or to “about” or “approximately” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. It is also understood that all spatial references, such as, for example, horizontal, vertical, top, upper, lower, bottom, left and right, are for illustrative purposes only and can be varied within the scope of the disclosure. For example, the references “upper” and “lower” are relative and used only in the context to the other, and are not necessarily “superior” and “inferior”. As used in the specification and including the appended claims, “treating” or “treatment” of a disease or condition refers to performing a procedure that may include administering one or more drugs to a patient (human, normal or otherwise or other mammal), employing implantable devices, and/or employing instruments that treat the disease, such as, for example, microdiscectomy instruments used to remove portions bulging or herniated discs and/or bone spurs, in an effort to alleviate signs or symptoms of the disease or condition. Alleviation can occur prior to signs or symptoms of the disease or condition appearing, as well as after their appearance. Thus, treating or treatment includes preventing or prevention of disease or undesirable condition (e.g., preventing the disease from occurring in a patient, who may be predisposed to the disease but has not yet been diagnosed as having it). In addition, treating or treatment does not require complete alleviation of signs or symptoms, does not require a cure, and specifically includes procedures that have only a marginal effect on the patient. Treatment can include inhibiting the disease, e.g., arresting its development, or relieving the disease, e.g., causing regression of the disease. For example, treatment can include reducing acute or chronic inflammation; alleviating pain and mitigating and inducing re-growth of new ligament, bone and other tissues; as an adjunct in surgery; and/or any repair procedure. Also, as used in the specification and including the appended claims, the term “tissue” includes soft tissue, ligaments, tendons, cartilage and/or bone unless specifically referred to otherwise. The following discussion includes a description of a spinal implant, a method of manufacturing a spinal implant, related components and methods of employing the surgical system in accordance with the principles of the present disclosure. Alternate embodiments are disclosed. Reference is made in detail to the exemplary embodiments of the present disclosure, which are illustrated in the accompanying figures. Turning toFIGS.1-3, there are illustrated components of a spinal implant system10including spinal implants, surgical instruments and medical devices. The components of spinal implant system10can be fabricated from biologically acceptable materials suitable for medical applications, including metals, synthetic polymers, ceramics and bone material and/or their composites. For example, the components of spinal implant system10, individually or collectively, can be fabricated from materials such as stainless steel alloys, aluminum, commercially pure titanium, titanium alloys, Grade 5 titanium, super-elastic titanium alloys, cobalt-chrome alloys, superelastic metallic alloys (e.g., Nitinol, super elasto-plastic metals, such as GUM METAL®), ceramics and composites thereof such as calcium phosphate (e.g., SKELITE™), thermoplastics such as polyaryletherketone (PAEK) including polyetheretherketone (PEEK), polyetherketoneketone (PEKK) and polyetherketone (PEK), carbon-PEEK composites, PEEK-BaSO4polymeric rubbers, polyethylene terephthalate (PET), fabric, silicone, polyurethane, silicone-polyurethane copolymers, polymeric rubbers, polyolefin rubbers, hydrogels, semi-rigid and rigid materials, elastomers, rubbers, thermoplastic elastomers, thermoset elastomers, elastomeric composites, rigid polymers including polyphenylene, polyimide, polyimide, polyetherimide, polyethylene, epoxy, bone material including autograft, allograft, xenograft or transgenic cortical and/or corticocancellous bone, and tissue growth or differentiation factors, partially resorbable materials, such as, for example, composites of metals and calcium-based ceramics, composites of PEEK and calcium based ceramics, composites of PEEK with resorbable polymers, totally resorbable materials, such as, for example, calcium based ceramics such as calcium phosphate, tri-calcium phosphate (TCP), hydroxyapatite (HA)-TCP, calcium sulfate, or other resorbable polymers such as polyaetide, polyglycolide, polytyrosine carbonate, polycaroplaetohe and their combinations. Various components of spinal implant system10may have material composites, including the above materials, to achieve various desired characteristics such as strength, rigidity, elasticity, compliance, biomechanical performance, durability and radiolucency or imaging preference. The components of spinal implant system10, individually or collectively, may also be fabricated from a heterogeneous material such as a combination of two or more of the above-described materials. The components of spinal implant system10may be monolithically formed, integrally connected or include fastening elements and/or instruments, as described herein. Spinal implant system10includes a spinal implant comprising a bone fastener, such as, for example, a bone screw12. In some embodiments, bone screw12includes variable, alternate, different and/or transition portions to optimize bone growth and/or fixation with tissue. In some embodiments, the portions of bone screw12can include a variable inner core. In some embodiments, the inner core is tapered to selectively provide a point of controlled deflection within bone screw12to resist and/or prevent pull out, toggle or fatigue fracture of bone screw12. In some embodiments, the portions of bone screw12can include an internal solid strut. In some embodiments, the portions of bone screw12can include a variable section thread and a solid strut. In some embodiments, the portions of bone screw12can include one or more cavities, for example, one or more pathways, openings, lattice and/or scaffold. In some embodiments, bone screw12can include even, uninterrupted portions, portions that are continuous and without cavity and/or solid portions. In some embodiments, bone screw12can include roughened portions, porous portions, trabecular portions and/or honeycomb portions. In some embodiments, bone screw12can include roughened portions, porous portions, trabecular portions and/or honeycomb portions. In some embodiments, bone screw12allows bone growth therethrough such that bone is allowed to connect through bone screw12. Bone screw12defines a longitudinal axis X1. Bone screw12includes a screw shaft18having a proximal portion14and a distal portion16. In some embodiments, bone screw12is manufactured by a manufacturing process to enhance fixation and/or facilitate bone growth, as described herein. In some embodiments, bone screw12is manufactured by an additive manufacturing method. In some embodiments, proximal portion14is fabricated by a first manufacturing method and distal portion16fabricated by a second manufacturing method to enhance fixation and/or facilitate bone growth, as described herein. In some embodiments, the manufacturing method can include a traditional machining method, such as, for example, subtractive, deformative or transformative manufacturing methods. In some embodiments, the traditional manufacturing method may include cutting, grinding, rolling, forming, molding, casting, forging, extruding, whirling, grinding and/or cold working. In some embodiments, the traditional manufacturing method includes portion14being formed by a medical machining process. In some embodiments, medical machining processes can include use of computer numerical control (CNC) high speed milling machines, Swiss machining devices, CNC turning with living tooling and/or wire EDM 4th axis. In some embodiments, the manufacturing method for fabricating portion14includes a finishing process, such as, for example, laser marking, tumble blasting, bead blasting, micro blasting and/or powder blasting. For example, portion14is formed by a manufacturing method, which includes feeding a wire, rod, bar, or wire or rod bar stock into a machine that cuts the wire at a designated length to form a screw blank and then forms a head of the screw blank into a selected configuration. Portion14is manufactured to include a head20and a portion of screw shaft18. Portion14extends between an end24and an end26. End24includes head20. Portion14includes threads28, which are fabricated by traditional machining methods, as described herein. Threads28extend along all or a portion of portion14. Threads28are oriented with portion14and disposed for engagement with tissue. In some embodiments, threads28include a fine, closely-spaced configuration and/or shallow configuration to facilitate and/or enhance engagement with tissue. In some embodiments, threads28include a smaller pitch or more thread turns per axial distance to provide a stronger fixation with tissue and/or resist loosening from tissue. In some embodiments, threads28include an increased greater pitch and an equal lead between thread turns. In some embodiments, threads28are continuous along portion14. In some embodiments, threads28are continuous along shaft18via a second manufacturing method, as described herein. In some embodiments, threads28may be intermittent, staggered, discontinuous and/or may include a single thread turn or a plurality of discrete threads. In some embodiments, other penetrating elements may be located on and/or manufactured with portion14, such as, for example, a nail configuration, barbs, expanding elements, raised elements, ribs, and/or spikes to facilitate engagement of portion14with tissue. End26includes a surface30that defines a distal end32. In some embodiments, surface30may be disposed along a length of portion14or at a distalmost surface of portion14. In some embodiments, distal end32extends perpendicular to axis X1. In some embodiments, distal end32may be disposed in various orientations relative to axis X1, such as, for example, transverse and/or at angular orientations, such as acute or obtuse. In one embodiment, distal end32is disposed at an acute angular orientation relative to axis X1. Distal end32is configured for providing a fabrication platform for forming portion16thereon with an additive manufacturing method, as described herein. Distal end32has a substantially planar configuration for material deposition and/or heating during an additive manufacturing process for fabricating portion16onto distal end32. In some embodiments, all or only a portion of distal end32may have alternate surface configurations, such as, for example, angled, irregular, uniform, non-uniform, offset, staggered, tapered, arcuate, undulating, mesh, porous, semi-porous, dimpled, pointed and/or textured. In some embodiments, distal end32may include a nail configuration, barbs, expanding elements, raised elements, ribs, and/or spikes to provide a fabrication platform for forming portion16thereon with an additive manufacturing method, as described herein. In some embodiments, all or only a portion of distal end32may have alternate cross section configurations, such as, for example, oval, oblong triangular, square, polygonal, irregular, uniform, non-uniform, offset, staggered, and/or tapered. Turning toFIG.3, portion16is fabricated with a second manufacturing method by disposing a material onto distal end32, as described herein. Portion16is configured for fabrication on distal end32such that portion16is fused with surface30. Portion16is formed on distal end32by an additive manufacturing method. Portion16is formed on distal end32to extend between an end40and end42according to instructions received from the computer and processor, and end40is fused with surface30. Portion16is fabricated according to instructions received from the computer and processor based on the digital rendering and/or data of the selected configuration, via the additive manufacturing process described herein to include a thread76that extends between end40and a distal tip44. In some embodiments, portion14is formed on an end of portion16. In some embodiments, portion14is formed on an end of head20. Portion16includes a wall50having a surface52. In some embodiments, wall50extends circumferentially to define portion16. In some embodiments, wall50is disposed about an inner core54, as described herein. In various embodiments, inner core54has a variable configuration, as described herein. In some embodiments, wall50defines a thickness, which may be uniform, undulating, tapered, increasing, decreasing, variable, offset, stepped, arcuate, angled and/or staggered. In some embodiments, surface52may be rough, textured, porous, semi-porous, dimpled, knurled, toothed, grooved and/or polished. Core54has a variable configuration and includes a tapered surface90to facilitate fixation with tissue. Surface90is angled at an angle A relative to axis X1. In various embodiments, surface90extends from a minor diameter MD1of screw12. In some embodiments, surface90starts to extend from minor diameter MD1at or adjacent where proximal portion14meets the distal portion16. In various embodiments, the surface90extends from the minor diameter, distally, through distal portion16. Surface90extends along all or a portion of core54. Surface90is angled relative to axis X1to define a tapered cross section. In some embodiments, surface90is uniformly tapered. In a contemplated embodiment, the surface90does not taper uniformly, such as by angle A being different along various points along the screw12. Variables for a designer to consider in determining whether and how to taper include a balance between any of strength for insertion of the screw12(e.g., torque strength), strength against breaking after implanted, and non-solid real estate for promoting bone growth into the screw (i.e., into lattice56. As an example, a designer may determine that core54being thicker proximally by a certain amount versus distally is appropriate to provide sufficient strength for insertion, wherein more strength may be determined needed in more proximal portions of the screw12than distally, where less strength is needed, and more lattice can be provided for more bone growth after implantation. Other variables include other supporting structure12of the screw, such as configuration of the thread form, such as whether fully or partially solid or non-solid. Other varying core widths, shapes, and angling can similarly be determined preferable to balance any of these or other such variables. In some embodiments, surface90may have various configurations, such as, for example, cylindrical, round, oval, oblong, triangular, polygonal having planar or arcuate side portions, irregular, uniform, non-uniform, consistent, variable, horseshoe shape, U-shape or kidney bean shape. In some embodiments, surface90defines a cross section of core54that decreases in diameter CD from end40to distal tip44. In a contemplated embodiment, the core54tapers distally toward the tip44to a zero or near-zero diameter. In some embodiments, surface90defines a cross section of core54that increases distally in diameter. Core54is configured to provide a selected point of deflection within bone screw12. For example, bone screws12are subjected to various loads when implanted with tissue, such as, for example, vertebrae. Core54is tapered to optimize the deflection of bone screw12when under loads, for example, an axial load or a cantilever load applied by vertebrae to resist and/or prevent pull-out. In some embodiments, core54is configured to provide an increased resistance to bending and/or lateral torsional buckling. In some embodiments, core54reduces the effects of shear stresses on bone screw12. In some embodiments, core54is configured to reduce an angle of twist. Core54extends within distal portion16and includes a solid configuration. In some embodiments, core54is continuous, or solid, without any internal openings and/or cavities. In some embodiments, core54includes a material having a closely compacted structure. In some embodiments, core54includes a solid configuration, which may include a range of density including 0.5 through 10.5 grams per cubic centimeter. In some embodiments, core54includes a density that is greater than a density of lattice56. In some embodiments, core54may include a porous configuration configured to facilitate bone growth. In some embodiments, the porous configuration may include a range of porosity over a wide range of effective pore sizes. In some embodiments, core54includes a trabecular configuration. In some embodiments, the trabecular configuration may include a density similar to cancellous or cortical bone tissue. Surface52includes a non-solid configuration, such as, for example, a lattice56. In some embodiments, the non-solid configuration may include a porous structure and/or a trabecular configuration. Disclosures herein involving a lattice, or other particular type of non-solid structure, are meant to disclose at the same time analogous embodiments in which other non-solid structure in addition or instead of the particular type of structure. In various embodiments, the non-solid configuration is configured to provide one or a plurality of pathways to facilitate bone through growth within, and in some embodiments all of the way through, from one surface to an opposite surface of bone screw12. Lattice56is continuous along surface52of portion16between end40and distal tip44. In some embodiments, lattice56extends along all or a portion of inner core54. Thread46is connected with lattice56to facilitate fixation of threads46with tissue. In some embodiments, lattice56may include one or more portions, layers and/or substrates. In some embodiments, one or more portions, layers and/or substrates of lattice56may be disposed side by side, offset, staggered, stepped, tapered, end to end, spaced apart, in series and/or in parallel. In some embodiments, lattice56defines a thickness, which may be uniform, undulating, tapered, increasing, decreasing, variable, offset, stepped, arcuate, angled and/or staggered. In some embodiments, one or more layers of lattice56are disposed in a side by side, parallel orientation within wall50. Lattice56includes one or more layers of a matrix of material. In some embodiments, lattice56includes a plurality of nodes64and openings66, which can be disposed in rows and columns, and/or in a random configuration. In some embodiments, nodes64and openings66are disposed in a series orientation. In some embodiments, nodes64and openings66are disposed in a parallel orientation. In some embodiments, lattice56may form a rasp-like configuration. In some embodiments, lattice56is configured to engage tissue, such as, for example, cortical bone and/or cancellous bone, such as, to cut, shave, shear, incise and/or disrupt such tissue. In some embodiments, all or a portion of each lattice56may have various configurations, such as, for example, cylindrical, round, oval, oblong, triangular, polygonal having planar or arcuate side portions, irregular, uniform, non-uniform, consistent, variable, horseshoe shape, U-shape or kidney bean shape. In some embodiments, lattice56may be rough, textured, porous, semi-porous, dimpled, knurled, toothed, grooved and/or polished to facilitate engagement and cutting of tissue. In some embodiments, lattice56forms a tunnel configured to guide, drive and/or direct the cut tissue into openings66to facilitate fusion of bone screw12with tissue, such as, for example, vertebrae. In some embodiments, wall50includes a trabecular configuration. Thread76has a variable configuration and includes an external thread form78. Thread form78has a flank79extending between a root R and a crest C. Thread76includes an external thread form78. Flank79has a variable configuration and includes a portion80and a portion82to facilitate bone growth and/or fixation with tissue. Portion80extends circumferentially about root R and includes a lattice configuration to facilitate fusion of bone screw12with tissue, as described herein. Portion80transitions from lattice56such that wall50and portion82are homogenous. In some embodiments, portion80includes a trabecular configuration. In some embodiments, the trabecular configuration may include a density similar to cancellous or cortical bone tissue. In some embodiments, portion80includes a porous configuration. In some embodiments, the porous configuration may include a range of porosity over a wide range of effective pore sizes. In some embodiments, the porous configuration of portion16may have macroporosity, mesoporosity, microporosity and nanoporosity. A surface88of the lattice of portion80is configured to engage tissue, such as, for example, cortical bone and/or cancellous bone, such as, to cut, shave, shear, incise and/or disrupt such tissue. In some embodiments, all or a portion of surface88may have various configurations, such as, for example, cylindrical, round, oval, oblong, triangular, polygonal having planar or arcuate side portions, irregular, uniform, non-uniform, consistent, variable, horseshoe shape, U-shape or kidney bean shape. In some embodiments, surface88may be rough, textured, porous, semi-porous, dimpled, knurled, toothed, grooved and/or polished to facilitate engagement and cutting of tissue. Portion82defines an even, uninterrupted edge surface of thread form78, and includes an even, solid surface relative to portion80, which provides a variable configuration of thread form78. Portion82extends along crest C forming an edge surface of thread form78that transitions from portion80and is configured to resist and/or prevent damage to tissue during insertion and/or engagement of bone screw12with tissue. Portion82is configured to resist and/or prevent damage to nerves, the dura and/or blood vessels. In some embodiments, portion82is continuous without any openings and/or cavities. In some embodiments, portion82includes a material having a closely compacted structure. In some embodiments, portion82includes a solid configuration, which may include a range of density including 0.5 through 10.5 grams per cubic centimeter. In some embodiments, portion82includes a density that is greater than a density of portion80. In some embodiments, thread76is fabricated to include a fine, closely-spaced and/or shallow configuration to facilitate and/or enhance engagement with tissue. In some embodiments, thread76is fabricated to include an increased pitch and an equal lead between thread turns than thread28, as shown inFIG.1. In some embodiments, thread76is fabricated to include a smaller pitch or more thread turns per axial distance than thread28to provide a stronger fixation with tissue and/or resist loosening from tissue. In some embodiments, thread76is fabricated to be continuous along portion16. In some embodiments, thread76is fabricated to be continuous along portion16. In some embodiments, thread76is fabricated to be intermittent, staggered, discontinuous and/or may include a single thread turn or a plurality of discrete threads. In some embodiments, portion16is fabricated to include penetrating elements, such as, for example, a nail configuration, barbs, expanding elements, raised elements, ribs, and/or spikes. In some embodiments, thread46is fabricated to be self-tapping or intermittent at distal tip44. In some embodiments, distal tip44may be rounded. In some embodiments, distal tip44may be self-drilling. In some embodiments, distal tip44includes a solid outer surface. For example, manipulation of bone screw12, including rotation and/or translation causes lattice56to cut tissue and/or shave bone such that the cut tissue is guided and/or directed into openings66to promote bone growth and enhance fusion of bone screw12. In some embodiments, external grating materials or biologics may be prepacked with bone screw12. Core54is configured to allow bone screw12to respond to loads applied by vertebrae and/or other implants by providing selected deflection to resist and/or prevent bone screw12pull out from tissue. In some embodiments, additive manufacturing includes 3-D printing, as described herein. In some embodiments, additive manufacturing includes fused deposition modeling, selective laser sintering, direct metal laser sintering, selective laser melting, electron beam melting, layered object manufacturing and stereolithography. In some embodiments, additive manufacturing includes rapid prototyping, desktop manufacturing, direct manufacturing, direct digital manufacturing, digital fabrication, instant manufacturing or on-demand manufacturing. In some embodiments, portion16is manufactured by additive manufacturing, as described herein, and mechanically attached with surface30by, for example, welding, threading, adhesives and/or staking. In one embodiment, one or more manufacturing methods for fabricating distal portion16, proximal portion14and/or other components of bone screw12include imaging patient anatomy with imaging techniques, such as, for example, x-ray, fluoroscopy, computed tomography (CT), magnetic resonance imaging (MRI), surgical navigation, bone density (DEXA) and/or acquirable 2-D or 3-D images of patient anatomy. Selected configuration parameters of distal portion16, proximal portion14and/or other components of bone screw12are collected, calculated and/or determined. Such configuration parameters can include one or more of patient anatomy imaging, surgical treatment, historical patient data, statistical data, treatment algorithms, implant material, implant dimensions, porosity and/or manufacturing method. In some embodiments, the configuration parameters can include implant material and porosity of distal portion16determined based on patient anatomy and the surgical treatment. In some embodiments, the implant material includes a selected porosity of distal portion16, as described herein. In some embodiments, the selected configuration parameters of distal portion16, proximal portion14and/or other components of bone screw12are patient specific. In some embodiments, the selected configuration parameters of distal portion16, proximal portion14and/or other components of bone screw12are based on generic or standard configurations and/or sizes and not patient specific. In some embodiments, the selected configuration parameters of distal portion16, proximal portion14and/or other components of bone screw12are based on one or more configurations and/or sizes of components of a kit of spinal implant system10and not patient specific. For example, based on one or more selected configuration parameters, as described herein, a digital rendering and/or data of a selected distal portion16, proximal portion14and/or other components of bone screw12, which can include a 2-D or a 3-D digital model and/or image, is collected, calculated and/or determined, and generated for display from a graphical user interface, as described herein, and/or storage on a database attached to a computer and a processor (not shown), as described herein. In some embodiments, the computer provides the ability to display, via a monitor, as well as save, digitally manipulate, or print a hard copy of the digital rendering and/or data. In some embodiments, a selected distal portion16, proximal portion14and/or other components of bone screw12can be designed virtually in the computer with a CAD/CAM program, which is on a computer display. In some embodiments, the processor may execute codes stored in a computer-readable memory medium to execute one or more instructions of the computer, for example, to transmit instructions to an additive manufacturing device, such as, for example, a 3-D printer. In some embodiments, the database and/or computer-readable medium may include RAM, ROM, EPROM, magnetic, optical, digital, electromagnetic, flash drive and/or semiconductor technology. In some embodiments, the processor can instruct motors (not shown) that control movement and rotation of spinal implant system10components, for example, a build plate, distal end32and/or laser emitting devices, as described herein. Portion14is fabricated with threads28by a first manufacturing method, as described herein. Portion14is connected with a part, such as, for example, a build plate in connection with an additive forming process and a second manufacturing method for fabricating distal portion16. Portion16is built up layer by layer and the melting process is repeated slice by slice, layer by layer, until the final layer of a material is melted and portion16is complete. Portion16is formed on distal end32to extend between an end40and end42according to instructions received from the computer and processor, and end40is fused with surface30. In some embodiments, the material is subjected to direct metal laser sintering (DMLS®), selective laser sintering (SLS), fused deposition modeling (FDM), or fused filament fabrication (FFF), or stereolithography (SLA). In some embodiments, portion16is fabricated in a configuration having a porosity via the additive manufacturing method, as described herein. In some embodiments, portion16is fabricated having a porosity with a porogen that is spheroidal, cuboidal, rectangular, elongated, tubular, fibrous, disc-shaped, platelet-shaped, polygonal or a mixture thereof. In some embodiments, a porosity of portion16is based on a plurality of macropores, micropores, nanopores structures and/or a combination thereof. In some embodiments, bone screw12includes an implant receiver (not shown) connectable with head20. In some embodiments, bone screw12can include various configurations, such as, for example, a posted screw, a pedicle screw, a bolt, a bone screw for a lateral plate, an interbody screw, a uni-axial screw, a fixed angle screw, a multi-axial screw, a side loading screw, a sagittal adjusting screw, a transverse sagittal adjusting screw, an awl tip, a dual rod multi-axial screw, midline lumbar fusion screw and/or a sacral bone screw. In some embodiments, the implant receiver can be attached by manual engagement and/or non-instrumented assembly, which may include a practitioner, surgeon and/or medical staff grasping the implant receiver and shaft18and forcibly snap or pop fitting the components together. In some embodiments, spinal implant system10comprises a kit including a plurality of bone screws12of varying configuration, as described herein. In some embodiments, bone screw12is selected from the kit and employed with a treatment at the surgical site. In one embodiment, bone screw12is fabricated to define a passageway through all or a portion of shaft18such that bone screw12includes a cannulated configuration and a plurality of lateral fenestrations in communication with the passageway. In assembly, operation and use, spinal implant system10is employed to treat an affected section of vertebrae. A medical practitioner obtains access to a surgical site including the vertebrae in any appropriate manner, such as through incision and retraction of tissues. The components of surgical system10including bone screw12are employed to augment a surgical treatment. Bone screw12can be delivered to a surgical site as a pre-assembled device or can be assembled in situ. Spinal implant system10may be may be completely or partially revised, removed or replaced. Surgical system10may be used with surgical methods or techniques including open surgery, mini-open surgery, minimally invasive surgery and percutaneous surgical implantation, whereby the vertebrae is accessed through a mini-incision, or sleeve that provides a protected passageway to the area. Once access to the surgical site is obtained, a surgical treatment, for example, corpectomy and/or discectomy, can be performed for treating a spine disorder. Bone screw12is connected with a surgical instrument, such as, for example, a driver (not shown) and is delivered to the surgical site. Bone screw12is manipulated including rotation and/or translation for engagement with cortical bone and/or cancellous bone. Manipulation of bone screw12causes lattice56to cut tissue and/or shave bone such that the cut tissue is guided and/or directed into openings66to promote bone growth and enhance fusion of bone screw12. Core54is configured to allow bone screw12to respond to loads applied by vertebrae and/or other implants by providing selected deflection to resist and/or prevent bone screw12pull out from tissue. In one embodiment, as shown inFIG.4, spinal implant system10, similar to the systems and methods described herein, includes a bone screw112, similar to bone screw12described herein. Bone screw112includes portion14, as described herein, and a portion116. Portion116includes a wall150, similar to wall50described herein, having a non-solid configuration, as described herein, such as, for example, a lattice156, similar to lattice56described herein. Wall150extends about a solid inner core154, similar to core54as described herein. Portion116includes a thread176. Thread176has a variable configuration, as described herein, and includes an external thread form178. Thread form178includes a flank179, similar to flank79as described herein. Flank179has a variable configuration and includes a trailing edge180and a leading edge182to facilitate bone growth and/or fixation with tissue. Trailing edge180defines an even, uninterrupted edge surface of thread form178, and includes an even, solid surface relative to portion182, which provides a variable configuration of thread form178. Trailing edge180transitions from inner core154such that inner core154and trailing edge180are homogenous. In some embodiments, trailing edge180is continuous without any openings and/or cavities, as described herein. Leading edge182includes a lattice configuration to facilitate fusion of bone screw112with tissue, as described herein. Leading edge182transitions from lattice156such that wall150and leading edge182are homogenous. In some embodiments, leading edge182includes a trabecular configuration. In some embodiments, leading edge182is continuous without any openings and/or cavities, as described herein, and trailing edge180includes a lattice configuration. In some embodiments, portion116is formed on distal end32by an additive manufacturing method, as described herein. In some embodiments, portion116is fabricated according to instructions received from the computer and processor based on the digital rendering and/or data of the selected configuration, via the additive manufacturing process, as described herein. Portion116is configured for fabrication on distal end32such that portion116is fused with surface30, as described herein. In one embodiment, as shown inFIG.5, spinal implant system10, similar to the systems and methods described herein, includes a bone screw212, similar to bone screw12described herein. Bone screw212includes portion14, as described herein, and a portion216. Portion216includes a variable configuration, as described herein, and includes a wall250. Wall250extends about a solid inner core254, similar to core54as described herein. Portion216includes a thread276having an external thread form278. Thread form278includes a flank279, similar to flank79as described herein. Wall250has a variable configuration and includes a portion280and a portion282to facilitate bone growth and/or fixation with tissue. Portion280includes a plurality of struts284that extend along portion216. Struts284are circumferentially disposed about portion216and define a cavity286therebetween. Struts284include an even, solid surface relative to portion282, as described herein. Struts274transition from inner core254to reinforce thread276to resist and/or prevent pull-out. Struts284include a tapered flange288. Flange288extends along all or a portion of flank279, which provides a variable configuration of thread form278. Flange288extends between an end300and an end302. Flange288includes an increase in diameter from end300to end302to support and/or strengthen thread form278. Portion282includes lattice286, similar to lattice56as described herein. Portion282is disposed with cavities286such that lattice286is non-continuous along portion216forming the variable configuration of wall250. Lattice286extends along all or a portion of flank279, which provides a variable configuration of thread form278with struts284. In some embodiments, portion282includes a trabecular configuration, as described herein. In some embodiments, portion216is formed on distal end32by an additive manufacturing method, as described herein. In some embodiments, portion216is fabricated according to instructions received from the computer and processor based on the digital rendering and/or data of the selected configuration, via the additive manufacturing process, as described herein. Portion216is configured for fabrication on distal end32such that portion216is fused with surface30, as described herein It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplification of the various embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

11857234

DETAILED DESCRIPTION OF THE DRAWINGS FIGS.1to5illustrate an exemplary embodiment of an orthopaedic bone stabilisation device100which is particularly suitable for stabilisation and healing of metacarpal bones. The stabilisation device100comprises an elongate body110having a length (L) which may range from 20 mm to 90 mm that may be made from any suitable material including but not limited to surgical grade stainless steel, Titanium and Titanium alloys. In the presently described embodiment, the elongate body110is shown to be cannulated with the cannula105extending through the entire elongate body110between a proximal end120and a distal end130. As a result, the elongate body comprises an inner diameter (Dc) and an outer diameter (D) which will be discussed in further detail throughout the specification. Any references to the term “diameter” hereinafter effectively refer to the outer diameter. In other alternative embodiments, the elongate body110may not have a cannula and in such embodiments the stabilisation screw100may have a slightly reduced diameter without departing from the spirit and scope of the disclosure. The elongate body110comprises a first threaded section112, a second threaded section114. The first threaded section112includes a head122located at the proximal end120that is adapted to interface with a driver. The head122may be configured to interface with any suitable driver configuration including but not limited to a torx-drive, hex head or any other suitable configuration. The first threaded section112has a length (L1) whereby L1is preferably 0.3 to 0.5 times the length (L) of the elongate body110. Referring toFIG.3in particular, the first threaded section112extends from the proximal end120to a first location117of the elongate body110such that the outer thread diameter (DT1) of the first section112gradually decreases from the proximal end120to the first location117of the elongate body110. In the preferred embodiment, the outer thread diameter (DT1) decreases uniformly in a direction from the proximal end120towards the first location117to provide a substantially tapered configuration for the first threaded section112. In other embodiments, the outer thread diameter DT1may decrease in a non-uniform manner without departing from the disclosure. Preferably, the outer thread diameter (DT1) of the first section at the proximal end is 1.2 to 1.6 times the outer diameter (DT1) of the first section112at the first location117resulting in the tapered configuration of the first threaded section112. The first threaded section112has a shank diameter denoted generally by D1. The shank diameter D1of the first section112also progressively decreases uniformly from the proximal end120towards the first location117and the shank diameter (D1) of the first section at the proximal end is 1.2 to 1.6 times the shank diameter (D1) of the first section112at the first location117. The importance of the configuration for the first threaded section112will be explained in detail in the foregoing sections. The second threaded section114has a length (L2) which extends between the distal end130and a second intermediate location119on the elongate body110. L2is preferably 0.3 to 0.5 times the length (L) of the elongate body110. The entire length of the second section114comprises helical threads. The second section114also has an outer thread diameter (DT2) and shank diameter (D2) and preferably these diameters are substantially equal to the outer thread diameter (DT1) and shank diameter (D1) respectively at the first location117. In some embodiments, the stabilisation device100may only comprise the first and second threaded sections112and114in which case the first location117and the second location119on the elongate body110may lie on the same point. However, in the presently described embodiment, the stabilisation device100further includes a non-threaded section116that is positioned between the first and second threaded sections112and114. The non-threaded section116does not have any helical threads thereon and has a length (L3) that lies between the first location117and the second location119. The length (L3) of the non-threaded section is preferably less than 0.5 times the length (L) of the entire elongate body110. Preferably, outer shank (D3) of the non-threaded section116is substantially equal to the shank diameter (D2) of the second section114. Once again, the importance of the configuration for the non-threaded section116will also be explained in detail in the foregoing sections. Advantageously, each of the first and second threaded sections112and114include cutting structures in the form of continuous helical flutes135that interrupt the helical threads of the first and second sections112and114. In at least one form, the stabilisation device100may be used for supporting or stabilisation of a damaged metacarpal bone during healing.FIG.6shows the skeletal system of a human hand with the metacarpal bones being highlighted. A method of installing the stabilisation device100may involve aligning the damaged metacarpal bone into an aligned position followed by insertion of a pin or a K-wire into the damaged metacarpal bone through the base portion of the metacarpal bone. As discussed above, insertion of the K-wire into a damaged bone is known. It would be understood by a skilled person that a K-wire with the appropriate size should be used depending on the physiological characteristics of the bone being repaired. For example, K-wires may be available in range of diameters from 0.8 mm to 1.6 mm. Once the K-wire has been inserted, the next step involves the use of a cannulated drill that uses the K-wire as a guiding means to drill a bore into the damaged bone. Preferably, the diameter of the cannulated drill bit being used to create the bore may be suitably sized to allow the diameter of the stabilisation device100to be accommodated within the bone. Once the bore has been suitably drilled into the damaged bone, a driver with a suitable interface is used to rotate and drive the stabilisation device100into the bore. As has been previously explained, the head122interfaces with the driver and the distal end130of the stabilisation device100is initially driven into the head portion/section (the first section) of the drilled bore of the damaged bone (requiring stabilisation). The second section114includes double threads that are intertwined and run parallel to each other. The provision of the double threads allows the lead distance of a thread to be increased without changing the pitch of the thread. For example, the double start thread for the second section114has double the lead distance when compared to a single start thread having the same pitch. Another design advantage of a multi-start thread provided on the second section114is that more contact surface is engaged in a single thread rotation. The insertion of the second section114into head of the metacarpal bone is followed by the insertion of the non-threaded section116of the stabilisation device. It is evident that the second section116of the stabilisation device100travels through a first section (head portion of the metacarpal bone) Progressing the second section114in the second section of the bore (within the body of the metacarpal bone) As the stabilisation device100is rotated further, the second section114of the stabilisation device progresses through the bore and enters a third section of the bore (base portion of the metacarpal bone) which in turn results in the non-threaded section116being located in the middle section of the bore (within the body of the metacarpal bone). Consequently, the first section112of the stabilisation device100becomes positioned within the first section of the bore in the bone (being stabilised). The first section112of the stabilisation device also includes a double thread structure which is beneficial for the same reasons as outlined in the previous sections. The pitch for the threads in the first section112is also substantially identical which ensure that the stabilisation device100does not apply a compressing force to bring any broken parts of the metacarpal bone M closer to each other by way of compression. The stabilisation device100has been shown in a stabilising configuration (stabilizing a typical metacarpal bone M) inFIG.7. The progressively increasing diameter of the first section112from the first location117to the proximal end120of the stabilisation device100provides additional surface area along the outer wall of the first section110especially around the proximal end120and the head122of the stabilisation device100thereby engaging a greater volume of bone tissue in the head portion of the metacarpal bone M. The slightly enlarged configuration of the first section112particularly at the proximal end120of the stabilisation device100provides improved engagement with the head portion of the metacarpal bone M which has a greater volume relative to the body portion of the metacarpal bone M. Without being bound by theory, the applicants hypothesize that the enlarged head122of the stabilisation device100reduces the likelihood of the stabilisation device head122breaking during insertion of the device100into the metacarpal bone M. Another important feature of the stabilisation device100in at least some embodiments relates to the non-threaded section116. Once the stabilisation device100has been fully inserted into the metacarpal bone M, the non-threaded section116is located in the thinnest part (body) of the metacarpal bone M. Unlike conventional screws which include threads along the entire length of such screws, the absence of any threads along section116is very helpful. Typically, any load acting along a convention screw would be translated to the bone via threads cutting into the bone tissue. In a section of reduced bone volume, the provision of such threads cutting into such volume can lead to increased instances of bone damage in the body section of the metacarpal bone. The absence of any threads in section116reduces the likelihood of any additional stress or strain being applied on the body portion of the metacarpal bone M during use. The following table provides exemplary lengths and diameters for the stabilisation device100manufactured in various different sizes to suit physiological requirements of various bone sizes. DiameterIncrements for(D2/D3)Length (L)each length range(L1)(L2)(L3)2.0 mm20-40 mm2mm0.3 L0.3 L0.4 L2.5 mm30-60 mm5mm0.3 L0.3 L0.4 L3.0 mm30-60 mm5mm0.3 L0.3 L0.4 L3.0 mm70 mm0.3 L0.3 L0.4 L3.5 mm40-60 mm5mm0.3 L0.3 L0.4 L3.5 mm70 mm0.3 L0.3 L0.4 L4.0 mm40-60 mm5mm0.3 L0.3 L0.4 L4.0 mm70-80 mm10mm0.3 L0.3 L0.4 L5.0 mm40-60 mm5mm0.3 L0.3 L0.4 L5.0 mm70-90 mm10mm0.3 L0.3 L0.4 L Referring toFIGS.8and9a second embodiment of the stabilisation device200has been illustrated. The elongate body210of the device200comprises a first threaded section212and a second threaded section214. The first threaded section212includes a head222located at the proximal end220that is adapted to interface with a driver. The head222may be configured to interface with any suitable driver configuration as explained in the earlier sections. The first threaded section212comprises a length (L1) whereby L1is preferably 0.3 to 0.5 times the length (L) of the elongate body110. Referring toFIG.7in particular, a first sub-section212A of the first threaded section212extends from the proximal end220to a first location217of the elongate body210such that the outer thread diameter (DT1) of the first sub section212A gradually decreases from the proximal end220to the first location217along the first sub-section212A. The outer thread diameter (DT1) of the first section212along the second sub-section2128is substantially constant. In the preferred embodiment, the outer thread diameter (DT1) decreases uniformly in a direction from the proximal end220towards the first location217to provide a substantially tapered configuration for the first sub-section212A for the first threaded section212. Preferably, the outer thread diameter (DT1) of the first sub-section212A at the proximal end220is 1.2 to 1.6 times the outer diameter (DT1) of the first subs-section212A at the first location217resulting in the initial tapered configuration of the first threaded sub-section212A. The first threaded section212has a shank diameter denoted generally by D1. The shank diameter D1of the first sub-section212A also progressively decreases uniformly from the proximal end220towards the first location217and the shank diameter (D1) of the first sub-section at the proximal end is 1.2 to 1.6 times the shank diameter (D1) of the first sub-section212A at the first location217. The configuration of the second section214in the device200is substantially similar to the configuration of the second section114as has been previously described in that the outer thread diameter and the shank diameter for the second section214remains substantially uniform along the length of the second section214. The configuration of the non-threaded section216is also substantially similar to the non-threaded section116as previously described. In compliance with the statute, the disclosure has been described in language more or less specific to structural or methodical features. The term “comprises” and its variations, such as “comprising” and “comprised of” is used throughout in an inclusive sense and not to the exclusion of any additional features. It is to be understood that the disclosure is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the disclosure into effect. The disclosure is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted by those skilled in the art.

11857235

While the present disclosure is subject to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. The invention should be understood to not be limited to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure. DETAILED DESCRIPTION In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. It will be apparent, however, to one of ordinary skill in the art that the invention disclosed herein may be practiced without these specific details. In other instances, specific numeric references such as “first screw,” may be made. However, the specific numeric reference should not be interpreted as a literal sequential order but rather interpreted that the “first screw” is different than a “second screw.” Thus, the specific details set forth are merely exemplary. The specific details may be varied from and still be contemplated to be within the spirit and scope of the present disclosure. The term “coupled” is defined as meaning connected either directly to the component or indirectly to the component through another component. Further, as used herein, the terms “about,” “approximately,” or “substantially” for any numerical values or ranges indicate a suitable dimensional tolerance that allows the part or collection of components to function for its intended purpose as described herein. In general, the present disclosure describes an apparatus and a method for a differential compression bone screw for compressing two adjacent bone portions together, including compressing bone fractures, fixating osteotomies, and joining fusions. The compression bone screw is comprised of a head portion and a distally extending shank. A center hole extends from the head portion to a distal end of the shank. The head portion is comprised of a superior end and an inferior end. The superior end includes a shaped opening that is substantially concentric with the center hole and configured to engagedly receive a tool for driving the compression bone screw into a hole drilled in a patient's bone. The inferior end includes a plurality of barbs that are disposed around the circumference of the inferior end and are configured to fixedly engage with surrounding bone tissue. Proximal threads and distal threads are disposed on the shank and configured to rotatably engage within the hole in the patient's bone, such that the compression bone screw advances into the hole upon being turned by way of the tool. A thread pitch of the distal threads preferably is greater than a thread pitch of the proximal threads, such that the compression bone screw comprises a differential pitch configured to compress the two adjacent bone portions, thereby closing a fracture there between. FIGS.1-4illustrate an exemplary embodiment of a compression bone screw100that may be used for repairing bone fractures, fixating osteotomies, joining fusions of the skeletal system, and the like. It should be understood that the terms “bone screw,” “fastener,” “fixator,” “elongate member,” and “screw” may be used interchangeably herein as they essentially describe the same type of device. The compression bone screw100generally is an elongate member comprised of a head portion104and a shank108. As best shown inFIGS.1-2, a cannulation or center hole112extends longitudinally from the head portion104to a distal end116of the shank108. The center hole112is configured to receive any of various guidewires, trocars, and other similar instruments for directing the bone screw to a hole drilled in the patient's bone. The head portion104is comprised of a superior end120and an inferior end124. As best illustrated inFIG.2, the superior end120may include a shaped opening128that is substantially concentric with the center hole112. The shaped opening128generally is configured to engagedly receive a tool suitable for driving the bone screw100into the hole drilled in the patient's bone. Although in the illustrated embodiment, the shaped opening128is comprised of a hexalobe shape, any of various multi-lobe shapes, as well as other polygonal shapes, are also contemplated. The inferior end124preferably is configured to countersink within the hole in the bone. Thus, the superior end120is not left protruding above the exterior surface of the bone once the compression bone screw100is fully engaged with the patient's bone. Further, a plurality of barbs132disposed around the circumference of the inferior end124are configured to engage with the surrounding bone tissue so as to prevent the bone screw from backing out of the hole in the patient's bone. In some embodiments, however, the inferior end124may be configured to be received within an opening of a bone fusion plate, such that the superior end120countersinks within the opening of the bone fusion plate and presses the plate against the surface of the patient's bone. As best shown inFIGS.3-4, the shank108is comprised of proximal threads136and distal threads140that share an intervening smooth portion144. The proximal threads136have a diameter138, and the distal threads140have a diameter142. A tapered diameter148extends from the distal threads140to a rounded portion152that comprises the distal end116. The smooth portion144is comprised of a diameter146that is less than the diameters138and142so as to facilitate passing the smooth portion144through the bone with relatively little resistance. Further, in the illustrated embodiment, the threads136and140share substantially similar exterior diameters,138and142, respectively, as shown inFIG.4. In some embodiments, however, the diameter138of the proximal threads136may be greater than the diameter142of the distal threads140. Various diameters of the proximal threads136and the distal threads140, as well as the diameter146, are contemplated, without limitation. The threads136and140are configured to rotatably engage within a suitably sized hole drilled in the patient's bone. Thus, turning the bone screw100in an appropriate direction by way of a tool coupled with the shaped opening128, drives the distal threads140to engage with bone tissue surrounding the hole, and thus advancing the bone screw100deeper into the hole in the bone. The proximal threads136engage the bone once a majority of the bone screw100is already disposed within the hole in the bone. Continued turning of the bone screw100then countersinks the inferior end124into an upper-most portion of the hole in the bone, and draws the superior end120beneath the exterior surface of the patient's bone. Moreover, the illustrated embodiment of the compression bone screw100comprises a differential pitch wherein the distal threads140have a thread pitch that is greater than the thread pitch of the proximal threads136. In operation, the greater thread pitch of the distal threads140pushes the bone portion near the distal threads toward the bone portion near the proximal threads136. The diameter146of the smooth portion144allows the fracture to close as the bone portions are compressed together. In some embodiments, the thread pitch of the distal threads140may range between substantially 1-3 times greater than the thread pitch of the proximal threads136. Preferably, however, the thread pitch of the distal threads140is substantially 2-times greater than the thread pitch of the proximal threads136. A wide variety of differential pitch configurations are contemplated within the scope of the present disclosure. It is contemplated that the differential pitch of the compression bone screw100is particularly well suited for compressing bone fractures, fixating osteotomies, joining fusions, as well as any other surgical procedure wherein compressing two adjacent bone portions is desired, without limitation. It is further contemplated that the compression bone screw100may be advantageously oriented longitudinally with respect to a patient's bone.FIG.5illustrates an exemplary use environment156wherein the compression bone screw100is longitudinally disposed within substantially the center of a repaired bone160. The proximal threads136and the distal threads140are engaged with healthy bone tissue, while a repaired fracture164is disposed along the smooth portion144. Further, the head portion104is countersunk within an entry hole168that was drilled into the repaired bone160by a surgeon. As will be appreciated, the compression bone screw100may be implemented in any of various lengths and diameters so as to advantageously repair a wide variety of differently sized and shaped bones within the human body. Furthermore, it is envisioned that the compression bone screw100may be configured for use in a veterinary capacity, and thus the bone screw100may be implemented with various shapes and sizes that are suitable for use in different types of animals. As will be appreciated, the rounded portion152and the tapered diameter148are configured to minimize resistance to forward movement of the compression bone screw100advancing within the interior of a bone hole. As best shown inFIG.1, the distal end116and the tapered diameter148of the bone screw100are further comprised of one or more flutes172that extend from adjacent of the center hole112and spiral along the tapered diameter148. A pair of cutting edges176borders each of the flutes172. Although the illustrated embodiment of the bone screw100comprises three flutes172, and thus six cutting edges176, more than or less than three flutes172and six cutting edges176may be incorporated into different implementations of the bone screw100without limitation. As will be appreciated, the cutting edges176advantageously clean the interior of the bone hole and increase the diameter of the hole to accept the distal threads140of the advancing bone screw100. As will be appreciated, the spiral, or a rate of twist, of the flutes172generally controls the rate of bone debris removal from the interior of the bone hole during rotation of the bone screw100. It is contemplated that the flutes172may be implemented with any of various spirals without deviating beyond the spirit and scope of the present disclosure. FIGS.6-7illustrate an exemplary embodiment of a compression bone screw180that may be used for repairing bones of a patient. The compression bone screw180is substantially similar to the compression bone screw100, illustrated inFIGS.1-3, with the exception that the compression bone screw180is comprised of intermediate threads184in lieu of the smooth portion144. As best shown inFIG.7, the intermediate threads184extend from the distal threads140to the proximal threads136, such that a continuous series of threads are disposed along substantially an entirety of the shank108. Further, a tapered diameter188extends from the distal threads140to the distal end116. The tapered diameter188and the distal end116are configured to minimize resistance to forward movement of the compression bone screw180advancing within the interior of a bone hole. It is contemplated that, in some embodiments, the tapered diameter188may be further comprised of one or more flutes172and cutting edges176that extend from the distal end116to the distal threads140, as described herein. The intermediate threads184may have a thread pitch that generally changes along the length of the shank108. In the illustrated embodiment ofFIGS.6-7, the intermediate threads184have a thread pitch that continuously decreases from the thread pitch of the distal threads140to the relatively smaller thread pitch of the proximal threads136. In some embodiments, the intermediate threads184may be comprised of a thread pitch near the distal threads140that ranges between substantially 1-3 times greater than the thread pitch of the intermediate threads that are near the proximal threads136. In some embodiments, the intermediate threads184may be comprised of a thread pitch near the distal threads140that decreases from substantially 2-times greater than the thread pitch near the proximal threads136. During operation of the compression bone screw180, the greater thread pitch of the distal threads140and nearby intermediate threads184pushes the bone portion near the distal threads toward the bone portion near the proximal threads136. As will be appreciated, during operation of the compression bone screw180, the decreasing thread pitch of the intermediate threads184contributes to compressing the bone portion near the distal threads140toward the bone portion near the proximal threads136. A wide variety of differential pitch configurations are contemplated within the scope of the present disclosure. Moreover, in some embodiments, wherein the proximal threads136have a larger diameter than the distal threads140, the intermediate threads184may be comprised of a diameter that continuously increases from the diameter of the distal threads140to the diameter of the proximal threads136. In some embodiments, the intermediate threads184may have a diameter that is larger than the diameter of the distal threads140and is smaller than the diameter of the proximal threads136. In still some embodiments, the diameter of the intermediate threads184may be substantially the same as the diameter of the distal threads140along a majority of the intermediate threads and then abruptly increase to match the diameter of the proximal threads136. It should be understood, therefore, that a wide variety of relationships between the shapes and sizes of the distal threads140, the intermediate threads184, and the proximal threads136are contemplate and may be implemented within the spirit and the scope of the present disclosure. While the invention has been described in terms of particular variations and illustrative figures, those of ordinary skill in the art will recognize that the invention is not limited to the variations or figures described. In addition, where methods and steps described above indicate certain events occurring in certain order, those of ordinary skill in the art will recognize that the ordering of certain steps may be modified and that such modifications are in accordance with the variations of the invention. Additionally, certain of the steps may be performed concurrently in a parallel process when possible, as well as performed sequentially as described above. To the extent there are variations of the invention, which are within the spirit of the disclosure or equivalent to the inventions found in the claims, it is the intent that this patent will cover those variations as well. Therefore, the present disclosure is to be understood as not limited by the specific embodiments described herein, but only by scope of the appended claims.

11857236

DETAILED DESCRIPTION Referring now to the drawings, an orthopedic screw used in practicing the method of the invention is shown at reference numeral10in the drawing Figures. Referring specifically toFIGS.1-4, the screw10is fabricated of, for example, surgical grade steel, titanium, alloys thereof or other suitable materials, including suitable medical-grade coatings and/or finishes. Screw10includes a unitary shaft12with screw threads14formed on the shaft12proximate a distal first end12A of the shaft12. The screw threads14terminate at a sharp, biting end edge16adapted to facilitate passage of the screw10axially through a lateral malleolus “M” and fibula “F” (seeFIGS.8and9) at a fracture site. Actual threads are 5.7 threads/cm for an HA 4.5 Screw and 6.7 threads/cm for an HA 4.0 Screw. Medical screw threads are defined as HA or HB. According to a preferred embodiment an HA 4.0 or an HA 4.5 screw thread is used, and are preferably “modified buttress threads.” The modified buttress thread is used to increase compression and prevent easy pullout of the screw10. An unthreaded shank18of the shaft12extends to a proximate second end12B of the shaft12and has a diameter less than the major diameter of the screw threads14. A head20is formed on the second end12B of the shaft12with a first tapered transition segment22formed at the juncture of the shaft12and an elongate enlarged head20such that rotation of the screw10provides progressively increased fracture-reducing pressure between the fibula and malleolus bone fragments as the first tapered transition segment22drives the malleolus against the fibula, as described in further detail below. The head20has a predetermined large diameter in relation to the diameter of the shaft12. The length of the screw threads14in relation to the overall length of the screw10is preferably approximately 19 to 31 percent. For example, for a screw10with a screw thread14length of 25 mm and a total shaft length of 130 mm, the screw threads14represent approximately 19 percent (25 mm/130 mm) of the total screw10length. For a screw10with a screw thread14length of 25 mm and a total shaft length of 80 mm, the screw threads14represent approximately 31 percent (25 mm/80 mm) of the total screw10length. A further enlarged proximal end24of the head20includes an axially-aligned socket26adapted for receiving a tool, for example a hex or star tool, and for rotating the screw10into aligned fibula and malleolus bone fragments at the fracture site. The head20transitions to the proximal end24of the head by a second tapered transition segment25. Rotation of the screw10provides progressively increased fracture-reducing pressure between the fibula and malleolus bone fragments as the second tapered transition segment25drives the malleolus against the fibula. Thus, both the first tapered transition segment22and the second tapered transition segment25collectively apply pressure as the screw10is driven into its required fixation position. This screw design provides three distinct spaced-apart points of compression along the length of the screw10that are capable of applying pressure required to reduce the fracture in a therapeutically appropriate manner. In situations where the fracture has a significant axial component that extends along a portion of both the malleolus and the fibula, the second tapered transition segment25insures that there will be pressure applied by the interaction with the screw threads14. A cannula28extends through the screw10from the socket26to the first end12A of the shaft12so that a Kirschner wire, known as a “K-wire” or “surgical wire” can be passed completely through the screw10to act as a guide when driving the screw10into the aligned fibula and malleolus bone fragments. FIGS.5and6show details of the socket26and the head20. FIG.7shows a version of the screw10with a socket30known as a “star” socket that has a 6-point star-shaped pattern that is rotated with a star bit, also referred to by its registered trademark “Torx.” Referring now toFIGS.8and9, to reduce a fracture a bore is formed in the lateral malleolus “M” and the medullary canal of the fibula “F.” As shown schematically, the bore in the malleolus includes a distal large diameter segment B1and a proximal small diameter segment B2communicating with the large diameter segment B1and defines a radially-inwardly extending shoulder B3. The bore in the medullary canal of the fibula F is shown at B4. To reduce the fracture, an incision is made in the ankle to expose a distal end of a lateral malleolus. A drill guide is placed into the incision abutting the exposed distal end of the lateral malleolus. A bit having a cannula therethrough is amounted into a driver and the bit is then inserted into the drill guide in proximity to the exposed lateral malleolus. The bit is driven into and through the lateral malleolus M and into a position proximate to and aligned with the medullary canal of the fibula F forming a bore B1-B4. A surgical wire32is inserted into the cannula of the bit while the bit is still positioned in the just-formed bore B1-B4in the lateral malleolus M and the medullary canal of the fibula F. The bit is then withdrawn, leaving the surgical wire32in the bore B1-B4to act as a guide for the screw10when inserted. A screw10is selected from a range of sizes, for example, an overall length of between 80 mm to 130 mm, a head20diameter of 5 mm to 6 mm and a head20length of between 20 mm and 40 mm. The screw10is guided on the wire32into the bore B1-B4of the fracture site. The screw10is rotated into a position where the lateral malleolus M and the fibula F are aligned in a fixed position in intimate contact and the fracture is thus reduced. The threads14of the screw10facilitate cortical purchase of the screw10within the medullary canal of the fibula F. The relatively long unthreaded shank18of the shaft12assists in preserving adequate thickness of the surrounding bone of the fibula F and distinguishes the screw10from prior art screws that include threads along the entire shaft of the screw. By continuing to rotate the screw10until the tapered transition segment22of the screw10bears against the shoulder B3of the bore in the malleolus M, the fibula F and the malleolus M are drawn together into a correctly aligned reduction position. Further rotation of the screw10drives the first tapered transition segment22of the screw into a compression state against the shoulder B3of the malleolus M. This method step also provides enhanced reduction that will improve healing by increasing blood flow between the adjacent bones at the fracture site. After the screw10is in its final position, the wire32is removed by withdrawing it from the cannula28of the screw10through the socket26. The above-procedures are preferably carried out using, for example, a fluoroscopy x-ray apparatus that permits the physician or technician to view in real-time the positions of the bones, drill bit, screw10and surgical wire32relative to each other, and to determine an appropriate screw size by positioning a screw10over the fracture site and viewing the juxtaposition of the screw in relation to the fracture. The screw can be manufactured in a range of sizes to facilitate use on patients of varying ages, gender and body size. A typical range of sizes is set out below: Total length of screw 1080-130mmLength of head 2020-40mmLength of threads 1425mmDiameter of enlarged terminal6.5mmend 24 of the head 20Diameter of head 205-6mmDiameter of unthreaded shank 182.9-3mmMajor diameter of threads 144-4.5mmAngle of first tapered transition4.5deg.segment 22Angle of second tapered15deg.transition segment 25 Detailed Method Sequence As shown inFIGS.10-12, there are various types of fractures of the malleolus, and the physician will exercise the training and experience to determine the precise manner in which the surgical use of the screw10occurs. As shown inFIG.13, a pre-op x-ray is viewed and a ruler is used to determine an estimated length of both proximal and distal portions of the screw10to be used. Attention should be taken to the size of the patient's canal. Typically, the 4.0 diameter screw is suitable. Under anesthesia with sterile field, a fluoroscopy unit is used to aid in the surgery. Direct surgeon visualization of the screen is recommended. As shown inFIG.14, (optional), a sterile screw can be placed over the lateral malleolus while taking a fluoroscopic x-ray to determine or verify appropriate screw sizing. Make a small incision as required to expose the distal tip of the fibula. As shown inFIG.15, with the foot inverted, insert the appropriate sized drill guide40until contact is made with the distal fibula. It is required to keep the guide40as medial as possible for adequate alignment. As shown inFIG.16, insert the appropriate drill bit46(4.0 mm or 4.7 mm) through the drill guide40creating a small opening in the distal fibula. The drill bit46can be inserted up to but not to exceed 40 mm. This depth is determined by the proximal portion of the desired screw10to be used. Under drilling may help create added compression during screw insertion. If drilling to the full depth of the proximal measurement of the screw10, this depth can be read off of the laser marking on the drill bit46, seeFIG.18. As shown inFIG.17, remove the drill bit46and insert a 225×1.3 mm k-wire50through the drill guide40and up the fibular canal using low power. Utilization of anterior/posterior and lateral fluoroscopy is required as the k-wire50is advanced up the canal of the fibula. Depth of the k-wire50should be inserted to a depth at least 25 mm past the fracture to create adequate compression. Optionally, the drill bit46may be left in the canal at this point as an aid to direct the k-wire50up the canal. Using this method will require use of the 300×1.3 mm k-wire50. As shown inFIG.18, remove the drill guide50and drill bit46. Use a wire depth gauge55to gauge the total length of the screw10to be used. If there is some displacement at the fracture site, it can be reduced before the k-wire50insertion with a bone clamp through the skin of a small incision. Remove the wire depth gauge55and choose the appropriate screw10diameter based on prior measurements and preoperative planning. As shown inFIG.19, insert the screw10over the k-wire50by hand with a screwdriver60. Hand insertion helps gauge the feel and adequate purchase of the threads. Fluoroscopy should be used to verify placement of the screw10above the fracture site. Continue until the head of the screw10is countersunk into the distal fibula. In dense bone, it may be required to use the countersink reamer on the screw driver60prior to screw insertion. As shown inFIG.20, confirm by anterior/posterior and lateral fluoroscopy the correct placement of the screw10. Remove the k-wire50and close the incision as desired by clip, suture, or steri-strips. Post op immobilization is at the discretion of the surgeon. Alternative Detailed Method Sequence This advanced surgical technique can be used by discretion of the surgeon and per the patient's needs. As shown inFIG.21, insert a 225×1.3 mm k-wire50by pressure into the canal to the desired depth. The drill guide40may be used as desired as a tissue protector. As shown inFIG.22, place the wire depth gauge55over the k-wire50until the gauge55contacts the distal fibula. Overall screw length is read off the end of the k-wire50. As shown inFIG.23, remove the wire depth gauge55and drill the distal fibula over the k-wire50with the appropriate sized drill bit46to the desired depth of the proximal screw portion. As shown inFIG.24, advance the appropriate sized screw10up the canal over the k-wire50with the screwdriver, removing the k-wire50after insertion. As shown inFIG.25, should the screw need to be removed, under anesthesia make a small incision in the skin below the fibula. Insert a k-wire50through the screw10and use the screwdriver60to remove the screw10and close the incision. However, for some patients, the screw10may not easily withdraw due to the screw threads stripping the fibular canal. In some implementations, this may result in the screw10rotating within the fibular canal without easily being removed. Alternatively or additionally, in some instances, calcification or various other buildup (ongrowth of new bone—osseoincorporation) may occur near the head20of the screw10, which can impede removal without a way to securely affix the screwdriver60to the screw10in order to remove the screw. In other examples, the head20of the screw10may itself become stripped, which can also lead to difficulty removing the screw10. Numerous solutions may exist for addressing some of these issues. One existing process to remove implants that are not easily removed may include using pliers used to grip the head20of the screw10; however, this may not work well if there is buildup around the head20of the screw10. Further, depending upon how well inserted the screw10is in the fibula, there may not be a lip or other outcropping on the head to grip with the pliers. Some existing methods have proposed using temperature change (e.g. endo ice used in a dental setting) to freeze or chill the metal of the implant thereby slightly shrinking the screw10so that it could be more easily removed. However, this technique risks damaging surrounding tissue and may not sufficiently shrink the screw10. If the head threading is stripped, one existing technique used to resolve this issue is to use glue to fill the head threading and to wait until it dries in order to provide better grip to the screwdriver, but this can be a prolonged process during surgery and would not be in the best interest of the patient. Another approach has been to increase friction using an abrasive that is positioned between the screwdriver and the threads of the head20, but this may cause abrasion to other tissues. Thus, the prior art has various shortcomings, and a need exists for improved methods, devices, and kits that can more easily facilitate removal of an orthopedic screw. Advantageously, disclosed herein is an orthopedic screw that includes, in part, a threaded cannula portion centrally located within a socket of an enlarged terminal end segment of a head of the orthopedic screw and at a focus point of the enlarged terminal end, where the threaded cannula portion extends along a cannula for at least a portion of a length of the head. Further, the threaded cannula portion includes a second threaded alignment opposite the first threaded alignment of the screw threads and configured to receive an instrument head adapted for rotating the implanted orthopedic screw for removal. The threaded cannula portion provides the physician with a way to insert an instrument head into the threaded cannula portion and affix the instrument head to the orthopedic screw such that the orthopedic screw can be more easily removed, particularly if the fibular canal is stripped or build up has occurred near the head of the orthopedic screw. FIG.26Aillustrates a perspective view of the head120of an implant100, according to one embodiment. The head120includes an enlarged proximal end124that includes a socket126for receiving a tool (e.g. a screwdriver with a hex or a star tool head) adapted for rotating the implant/screw100into one or more bone segments at the fracture site. Further, as shown, a threaded cannula portion129of a cannula128is centrally located at a focus point of the enlarged terminal end124. The threaded cannula portion129comprises a hollow cylindrical channel that forms a portion of the cannula128. FIG.26Billustrates a cross-sectional view of the implant100ofFIG.26A, andFIG.26Cdepicts a magnified view of the portion of the cross-section of the implant100. The head120includes a length extending from an enlarged proximal end124and the second end112B of the shaft112. As depicted, the threaded cannula portion129extends along the cannula128for at least a portion of the length of the head120. Further, the implant100includes a unitary shaft112with screw threads114with a first threaded alignment formed on the shaft112proximate a distal first end112A of the shaft112. The screw threads114terminate at a sharp, biting end edge116adapted to facilitate passage of the implant/screw100through one or more bone segments. Further, the threaded cannula portion129includes a threaded alignment that is opposite the first threaded alignment of the screw threads114. Further, the threaded cannula portion129is configured to receive an instrument head (e.g. seeFIGS.27-29) adapted for rotating the implant/screw100for removal. An unthreaded shank118of the shaft112extends to a proximate second end112B of the shaft112and has a diameter less than the major diameter of the screw threads114. A head120is formed on the second end112B of the shaft112with a first tapered transition segment122formed at the juncture of the shaft112and an elongate enlarged head120such that rotation of the implant/screw100provides progressively increased fracture-reducing pressure between the one or more bone segments as described above. The head120transitions to the proximal end124of the head120by a second tapered transition segment125positioned at a juncture of the head120and the enlarged terminal end segment of the head120. The second tapered transition segment125helps provide progressively increased fracture-reducing pressure to the one or more bone segments. The head120has a predetermined large diameter in relation to the diameter of the shaft112. Further, the threaded cannula portion129includes a diameter (i.e., a major diameter) that is less than a total diameter of the socket126. The threaded cannula portion129includes threads131having a root133and a crest135and include a thread angle137sized and shaped or otherwise configured to align with threads254(seeFIG.27) of a threaded end252A (seeFIG.27) of an instrument200(seeFIG.27) for implant removal. The threads131include multiple diameters, where the major diameter139(corresponding to the crest135) is less than a total diameter of the socket126and is the widest point of the threads131, a minor diameter141(corresponding to the root133) is the narrowest point of the threads, and a pitch diameter143varies across the thread angle137of the threads131. FIG.27illustrates a perspective view of a kit that includes the implant100ofFIGS.26A-26Cand an instrument200for implant removal, according to one embodiment. The instrument200includes an instrument head250and includes an instrument shaft252extending from a threaded end252A to a tang end252B, wherein threads254of the threaded end252A are configured to correspond to threads131(seeFIGS.26A-26C) of the threaded cannula portion129. Further, a tang256of the tang end252B include a notched head258configured to fit into a driving device socket of a driving device (e.g. a socket wrench screwdriver). According to one embodiment, the notched head258includes a partially cylindrical configuration. For example, in some embodiments, a portion of the notched head may be shaved, cut, or otherwise missing from the cylindrical configuration such that the notched head may only be partially cylindrical. FIG.28Aillustrates a cross sectional view andFIG.28Billustrates a perspective view of the implant100ofFIGS.26A-27with the instrument200for implant removal ofFIG.27inserted therein, according to one embodiment. The threaded end252A of the instrument200is secured to the implant100via the threaded cannula portion129of a cannula128that is located at the focus point of the enlarged terminal end124of the implant100. FIG.29illustrates a method of implant removal, according to one embodiment. As depicted the instrument200is affixed to the implant100by turning the instrument200counter clockwise. Once secured, the physician would then continue to turn the instrument200to the left in order to dislodge the implant100from the one or more bone segments. FIG.30illustrates example method300steps for removing an implant, according to one embodiment. At block305, a physician would access an implanted orthopedic screw previously implanted in one or more bone segments of a patient, where the orthopedic screw includes a unitary shaft and includes (i) screw threads that include a first threaded alignment, that have a diameter, and that are formed on a first, distal end of the shaft. Further, a terminal end portion of the screw threads includes an end edge adapted to facilitate passage of the screw through the one or more bone segments at a fracture site. The orthopedic screw also includes (ii) an unthreaded shank having a diameter less than the diameter of the screw threads, and (iii) a head positioned on a second, proximal end of the shaft integrally-formed to the shank and having a diameter greater than the diameter of the screw threads and the shank. The orthopedic screw also includes (iv) an enlarged terminal end segment of the head that includes (1) a socket for receiving a tool adapted for rotating the screw into the one or more bone segments at the fracture site, and (2) a threaded cannula portion centrally located within the socket at a focus point of the enlarged terminal and extending along a cannula for at least a portion of a length of the head. The threaded cannula portion includes a second threaded alignment opposite the first threaded alignment of the screw threads and is configured to receive an instrument head adapted for rotating the implanted orthopedic screw for removal. At block310, the instrument head adapted for rotating the implanted orthopedic screw is fastened to the threaded cannula portion of the enlarged terminal end. At block315, the implanted orthopedic screw is at least partially withdrawn from the one or more bone segments by rotating the instrument head. In some embodiments, the method300further includes making an incision to the patient's skin across the patient's lateral malleolus and centered along a long axis of the patient's fibular shaft and retracting the skin to access the implanted orthopedic screw. Further, the method300may also include closing the incision. Aspects of the present invention are described herein with reference to flowchart illustrations and/or block diagrams according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be performed out of the order noted in the Figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the process involved. While the invention has been described in relation to medical treatment of humans and specifically the reduction of a fracture of the lateral malleolus and fibula, the screw according to the disclosure of this application has applications in fracture reduction in other parts of the human body and in veterinary medical practice. A cannulated orthopedic screw according to the invention has been described with reference to specific embodiments and examples. Various details of the invention may be changed without departing from the scope of the invention. Furthermore, the foregoing description of the preferred embodiments of the invention and best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation, the invention being defined by the claims.

11857237

MODE FOR INVENTION Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. All terms used herein are the same as general meanings of terms that those skilled in the art understand unless specifically defined, and if terms used herein have meanings conflicting with general meanings of the terms, the definition used herein has priority. However, the following description is provided to describe embodiments of the present disclosure without limiting the scope of the present disclosure, and same reference numerals used throughout the specification indicate the same components. FIG.1is a view showing forceps for internal fixation according to an embodiment of the present disclosure before it is assembled,FIG.2is a top view of the forceps for internal fixation according to an embodiment of the present disclosure,FIG.3is a perspective view of a first member and a second member according to an embodiment of the present disclosure, andFIG.4is a perspective view of a fourth member according to an embodiment of the present disclosure. Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. All terms used herein are the same as general meanings of terms that those skilled in the art understand unless specifically defined, and if terms used herein have meanings conflicting with general meanings of the terms, the definition used herein has priority. However, the following description is provided to describe embodiments of the present disclosure without limiting the scope of the present disclosure, and same reference numerals used throughout the specification indicate the same components. Referring toFIGS.1to4, forceps100for internal fixation according to an embodiment of the present disclosure, in a broad meaning, may include a first member110, a second member120, and a third member130, and may further include a fourth member140. In order to more clearly describe the technical characteristics of the present disclosure before describing the configuration of the present disclosure, the direction in which the forceps100for internal fixation according to an embodiment is moved toward bone fragments10is defined as a front direction, the opposite direction is defined as a rear direction. Further, the direction going to a first member110to be described below is defined as a left direction and the direction going to a second member120to be described below is defined as a direction. The surfaces facing each other of the first member110and the second member120to be described below are defined as inner surfaces. The first member110may have a first holding portion111for holding a first side of the bone fragment10and a first grip112extending from the first holding portion111. The second member120may have a second holding portion121for holding a second side spaced a predetermined distance from the first side of the bone fragment10and a second grip122extending from the second holding portion121. The first member110and the second member120are provided in a pair, thereby being able to achieve the function of forceps for holding the bone fragments10and a third member130to be described below. The first side and the second side of the bone fragment10may be both sides of a third side of the bone fragment10to which the third member130to be described below is placed. In the forceps100for internal fixation according to an embodiment of the present disclosure, the inner surface of the first holding portion111may be formed to correspond to the first side of the bone fragment10and the inner surface of the second holding portion121may be formed to correspond to the second side of the bone fragment10. That is, the forceps100for internal fixation according to an embodiment of the present disclosure may function as customized forceps, depending on detailed shapes of bone fragments10photographed by medical equipment, and the inner surface of the first holding portion111and the inner surface of the second holding portion121can accurately hold desired portions of the bone fragment10, so it is possible to more precisely place the third member130to be described below to a desired position. In order to match the shapes of the inner surface of the first holding portion111and the inner surface of the second holding portion121, the first member110and the second member120according to an embodiment of the present disclosure may be formed through a3D printer on the basis of data based on the detailed shapes of the bone fragments10photographed by medical equipment. A prominence-depression portion113,123is formed on a portion or the entire of the inner surface of the first holding portion111or the inner surface of the second holding portion121, so the forceps can tightly hold the bone fragment10. The prominence-depression portions113and123, as shown in the figures, may be longitudinally elongated, but are not limited thereto and may be formed in a protrusion shape. In other words, the first member110and the second member120may be formed to entirely correspond to each other in a pair, but the inner surface of the first holding portion111and the inner surface of the second holding portion121may be formed in different shapes, depending on the shapes of the bone fragments10. The third member130, which is disposed on the third side of the bone fragment10between the first side and the second side of the bone fragment10and is screw-fastened to the third side of the bone fragment10, may be generally referred to as a metal plate or a plate. Accordingly, the third member130may have one or more fastening holes131at two sides. The third member130according to an embodiment of the present disclosure, unlike existing metal plate, may have an inner surface (front) formed to correspond to the shape of the third side of the bone fragment10. Accordingly, the third member130can be precisely placed at a position for fixing both bone fragments10. For customized shape of the inner surface of the third member130, the third member130according to an embodiment of the present disclosure may be manufactured through a3D printer on the basis of data based on the detailed shape of the bone fragments10photographed by medical equipment. In order to tightly hold the third member130disposed on the third side of the bone fragment10, the first member110may further has a fixing portion114that fixes a portion of the third member130to the third side of the bone fragment10between the first holding portion111and the first grip. Further, the second member120may further have a second fixing portion124that fixes the other portion of the third member130to the third side of the bone fragment10between the second holding portion121and the second grip122. The first fixing portion114and the second fixing portion124may be implemented in two exemplary types. First, the first fixing portion114and the second fixing portion124are integrally formed with the first member110and the second member120. That is, the first fixing portion114may extend from the first grip111in a shape corresponding to a portion of the third member130to be held, and the second fixing portion124may extend from the second grip121in a shape corresponding to the other portion of the third member130to be held. When the entire forceps for internal fixation according to an embodiment of the present disclosure is formed in a customized type in accordance with the shape of the bone fragment10, a holding force can be secured in this first embodiment. Second, the first fixing portion114and the second fixing portion124are provided independently from the first member110and the second member120. That is, the first fixing portion114may have a first fixing member114ahaving a side having a shape corresponding to a portion of the third member130, and a first elastic member114bdisposed between another side of the first fixing member114aand the first holding portion111or between another side of the first fixing member114aand the first grip112and applying pressure to the first fixing member114a. That is, the second fixing portion124may have a second fixing member124ahaving a side having a shape corresponding to the other portion of the third member130, and a second elastic member124bdisposed between another side of the second fixing member124aand the second holding portion121or between another side of the second fixing member124aand the second grip122and applying pressure to the second fixing member124b. According to the second embodiment, there is an effect of pressing the third member130forward, that is, toward the bone fragment10, so the third member130can be more precisely placed at a desired position. The present disclosure may further include a scope for further increasing the holding force. In detail, the first member110may further have a coupling groove115formed on the inner surface of the first grip112and the second member120may further has a coupling protrusion124formed on the inner surface of the second grip122to face the coupling groove114and configured to be fitted in the coupling groove115. This structure can prevent the first member110and the second member, which hold the first side and the second side of the bone fragment10, from twisting and moving forward and rearward. In order to further secure this effect, the coupling protrusion125and the coupling groove115each may be formed at least two positions to face each other, respectively. The forceps may further include a fourth member140retaining the first grip112and the second grip122, thereby providing a fixing force to the first member110and the second member120. The first member110and the second member120that hold the bone fragment10can be firmly fixed by the fourth member140. In order to further secure the holding force, the first grip112and the second grip112may be narrowed toward the free ends, and the inner surface of the fourth member140may be formed to correspond to the first member110and the second member120, thereby being able to achieve the coupling force by a wedge. In order to further increase the holding force, at least one or more first fixing protrusions116may be formed on the outer surface of the first grip112, at least one or more second fixing protrusions126may be formed on the outer surface of the second grip122, and fixing grooves141corresponding to the first fixing protrusion116and the second fixing protrusion126may be formed on the inner surface of the fourth member140. In short, the present disclosure has a structure being able to perform surgery after partially cutting the skin and the muscle to place the third member130to the bone fragments10and holds not only bone fragments10to be reduced, but the third member130, thereby being able to perform more precise surgery. It would be understood by those skilled in the art that the present disclosure may be changed and modified in various ways without departing from the spirit of the present disclosure, and the scope of the present disclosure is not limited to those described in the embodiments and should be determined by claims and equivalent ranges.

11857238

DETAILED DESCRIPTION The present invention relates to a ratchet system. The ratchet system comprises:at least one handle comprising a distal end and a connection surface;at least one rod comprising a male distal end, a proximal end and a contact surface, said proximal end comprising a cavity;cooperation means including:at least two lugs positioned on the distal end of the handle;at least two grooves positioned on the internal wall of the cavity of the rod, each of the at least two grooves comprising a helical portion, one of the ends of which is a wall perpendicular to said internal wall; the at least two lugs each cooperating in a predetermined rotation direction with one of the at least two grooves so as to be in contact with said perpendicular wall, said contact allowing the driving, in the predetermined rotation direction, of the rod, by the handle; wherein the proximal end of the rod is adapted to cooperate with the distal end of the handle through the cooperating means until contact between the connection surface with the contact surface, in order to drive the rod in the same rotation direction. The distal end of the handle is configured to fit into the cavity formed in the proximal end of the rod. During this operation, the lugs are supported and slide along the grooves dug in said cavity until they are each in contact with a perpendicular wall machined in the internal wall of the cavity, and that the connection surface of the handle is in contact with the contact surface of the rod. The walls perpendicular to the internal wall of the cavity of the proximal part of the rod are then rotated by the lugs in a predefined direction of rotation by the downward orientation (from the proximal end to the distal end) of the grooves: clockwise or anti-clockwise. As a result, a rotational movement is applied to the rod. If, by an untimely gesture, the handle is actuated in a direction of rotation opposite to that predefined by the downward orientation of the grooves, the lugs separate from the perpendicular walls, their ends slide and go up on the grooves, thus preventing training of the rod rotating in the direction of rotation opposite to the predefined one. The ratchet system of the invention therefore advantageously makes it possible to control a direction of rotation, clockwise or anti-clockwise, to transmit a movement in a determined direction and, above all, to prevent any untimely gesture from leading to the transmission of the movement. reverse. This is particularly useful for use of said system in a screwdriver since only one direction of rotation, corresponding to screwing or unscrewing, can be applied to the rod. In the case of a screwdriver comprising the ratcheting system according to the invention, said system makes it possible to screw without the risk of inadvertently unscrewing and, conversely, of unscrewing without the risk of inadvertently screwing any object composed of one or more elements. The handle is configured in a way that the lugs separate from the wall when the handle is moved in the opposite direction than the predetermined direction. The rod is a drive mechanism, able to drive a screw for example in a chosen direction of rotation. According to one embodiment, the at least one rod is a screw rod. According to one embodiment, the at least one rod is an unscrewing rod. According to one embodiment, the ratchet system comprises a screwing rod and an unscrewing rod. According to one embodiment, the proximal end of the at least one rod and the distal end of the at least one handle displays a cylindrical shape. According to one embodiment, the ratchet system is dismountable. In this embodiment, the elements of said ratchet system (handle, rod) are independent of each other and can be separated, advantageously for easy cleaning. According to one embodiment, the ratchet system is sterilizable. According to one embodiment, the various elements of the ratchet system can be sterilized. According to one embodiment, the ratchet system further comprises a handle. In this embodiment, the handle is connected to the handle by a connection surface. According to one embodiment, the handle comprises a shaft. In this embodiment, the handle and the shaft can be merged, i.e., be the same element of the ratchet system. According to one embodiment, the distal end of the handle displays a cylindrical shape. This embodiment is particularly advantageous because the cylindrical shape facilitates the rotation of the distal end of the handle. Another shape could indeed hinder the rotation of the distal end of the handle. According to one embodiment, the ratchet system includes the same number of lugs and grooves. According to one embodiment, the ratchet system comprises at least 2, 3, 4, 5, 6, 7, 8, 9, or 10 lugs distributed over the distal end of the handle. The number of lugs determines the rotation of the wrist to screw or unscrew comfortably while being effective. The presence of 3 lugs is particularly advantageous in terms of efficiency, especially in the case of screwing. The presence of 6 pins is particularly advantageous in terms of precision. According to one embodiment, the ratchet system comprises 2 lugs distributed over the distal end of the handle. According to one embodiment, the ratchet system comprises 2 lugs distributed over the distal end of the handle and 2 grooves positioned on the internal wall of the cavity of the rod. According to one embodiment, the ratchet system comprises 3 lugs distributed over the distal end of the handle. The presence of 3 lugs is particularly advantageous in terms of efficiency, especially in the case of screwing. The presence of 3 lugs equally distributed around the distal end of the handle offers a more comfortable and a more physiologically adapted handling. According to one embodiment, the ratchet system comprises 3 lugs distributed over the distal end of the handle and 3 grooves positioned on the internal wall of the cavity of the rod. According to one embodiment, the at least two lugs are evenly distributed over the distal end of the handle. According to one embodiment, the at least two lugs have rounded ends. This embodiment is particularly advantageous because the rounded shape of the ends of the lugs allows the reversible movement consisting in being engaged and disengaged in the at least two grooves positioned on the internal wall of the cavity of the rod. According to one embodiment, the at least one rod comprises a cylindrical body. This embodiment is particularly advantageous because the cylindrical shape makes it possible to limit the friction between the rod and another element of the screwing system. According to one embodiment, at least one rod has a length of between 1 and 50 cm, preferably between 5 and 40 cm, more preferably between 5 and 20 cm. According to one embodiment, the length of the at least one rod depends on the use made of the screwing system. For example, for applications in interventional radiology in particular, or in surgery in general, a short rod (that is to say having a length between 5 and 10 cm) will be used for screwing/unscrewing specific screws in small superficial bones such as vertebrae; a long rod (i.e. having a length greater than 20 cm) will be used for bones such as those of the pelvis (pelvis and sacrum). According to one embodiment, the proximal end of the at least one rod is cylindrical in shape. According to one embodiment, the proximal end of the at least one rod has a length of between 1 and 10 cm, preferably between 1 and 5 cm. According to one embodiment, the length of the proximal end of the at least one rod depends on the use made of the screwing system. For example, for applications in interventional radiology in particular, or in surgery in general, a short rod (that is to say having a length between 5 and 10 cm) will be used for screwing/unscrewing specific screws in small superficial bones such as vertebrae; a long rod (i.e. having a length greater than 20 cm) will be used for bones such as those of the pelvis (pelvis and sacrum). According to one embodiment, the proximal end of the at least one rod has a diameter of between 0.1 and 5 cm, preferably between 0.2 and 2 cm. According to one embodiment, the diameter of the proximal end of the at least one rod depends on the use made of the screwing system. In particular, a short stem (length between 5-10 cm) will have a smaller diameter than a long stem (length greater than 20 cm). According to one embodiment, the proximal end of the at least one rod is a bore. According to one embodiment, the proximal end of the at least one rod is a bore comprising at least two threads. According to one embodiment, the at least two grooves are also distributed over the inner wall of the proximal end of the at least one rod. According to one embodiment, the at least two grooves are machined in the inner wall of the proximal end of the at least one rod. According to one embodiment, the at least two grooves are obtained by turning the internal wall of the proximal end of the at least one rod. According to one embodiment, the at least two grooves each describe a channel of helical or sinusoidal shape on the inner wall of the proximal end of the at least one rod. According to one embodiment, the at least two grooves extend between the proximal end and the distal end of the at least one rod over a distance of between 0.5 and 5 cm, preferably between 0.5 and 3 cm. According to one embodiment, the distance at which the at least two grooves extend between the proximal end and the distal end of the at least one rod depends on the use made of the screwing system. According to one embodiment, the at least two grooves each comprise a helical portion descending from the proximal end of the rod towards the distal end of the rod. According to one embodiment, the at least two grooves each comprise a helical portion descending from the proximal end of the rod towards the distal end of the rod in a clockwise direction. According to one embodiment, the at least two grooves each comprise a helical portion descending from the proximal end of the rod towards the distal end of the rod in a counterclockwise direction. According to one embodiment, the at least two grooves each describe a downward slope in a clockwise direction from the proximal end of the at least one rod towards the distal end of the at least one rod. According to one embodiment, the at least two grooves each describe a downward slope in a counterclockwise direction from the proximal end of the at least one rod towards the distal end of the at least one rod. According to one embodiment, the depth of the at least two grooves depends on the diameter of the rod and on the number of grooves. According to one embodiment, the at least two grooves each have a length of between 0.5 and 5 cm, preferably between 0.5 and 3 cm. According to one embodiment, the length of the at least two grooves depends on the use made of the screwing system. According to one embodiment, the at least two grooves each have a helical radius of between 0.1 and 5 cm, preferably between 0.2 and 2 cm. According to one embodiment, the helical radius of the at least two grooves depends on the use made of the screwing system, more precisely, it depends on the diameter of the rod. According to one embodiment, the at least two grooves are internal threads. According to one embodiment, the walls perpendicular to the internal wall of the cavity are machined in the internal wall of the proximal end of the at least one rod. According to one embodiment, the proximal end of the at least one rod and the distal end of the at least one handle are cylindrical in shape. According to one embodiment, the ratchet system is a screwing and/or unscrewing means. According to one embodiment, the latching system is a screwdriver, a key, or any other screwing and/or unscrewing means known to those skilled in the art. According to one embodiment, the ratchet system is a screwdriver suitable for use in surgery. According to one embodiment, the ratchet system is a screwdriver suitable for use in orthopedic surgery. According to one embodiment, the ratchet system is a surgical tool. According to one embodiment, the ratchet system is a surgical screwdriver. According to one embodiment, the latching system is suitable for screwing and/or unscrewing an object comprising one or more elements. In this embodiment, the elements are assembled or pre-assembled by threaded or tapped joints, with conventional or reverse pitches. The present invention also relates to a ratchet system. The invention relates to a ratchet system comprising:at least one handle comprising a distal end, said distal end comprising a cavity;at least one rod comprising a male distal end and a proximal end;means of cooperation including:at least two grooves positioned on the internal wall of the cavity of the handle, each of the at least two grooves comprising a helical portion, one of the ends of which is a wall perpendicular to said internal wall;at least two lugs positioned on the proximal end of the rod; the at least two lugs each cooperating with one of the at least two grooves until coming into contact with said perpendicular wall; wherein the proximal end of the rod is adapted to cooperate with the distal end of the handle through the cooperation means. In one embodiment, the at least one handle is a screw handle. In one embodiment, the at least one handle is an unscrewing handle. In one embodiment, the ratchet system includes a screwing handle and an unscrewing handle. In one embodiment, the proximal end of the at least one rod and the distal end of the at least one handle are cylindrical in shape. The handle and its distal end, the rod and its proximal end, the cooperation means, namely the lugs, grooves and perpendicular walls are as described above. The present invention is about a ratchet system. The ratchet system includes:at least one handle comprising a distal end and a connection surface;at least one rod comprising a male distal end, a proximal end and a contact surface;means of cooperation including:at least two lugs;at least two grooves positioned on the internal wall of a cavity, each of the at least two grooves comprising a helical portion, one end of which is a wall perpendicular to said internal wall; the at least two lugs each cooperating with one of the at least two grooves until they come into contact with said perpendicular wall; wherein the proximal end of the rod is adapted to cooperate with the distal end of the handle through the cooperating means until contact between the connection surface with the contact surface. In one embodiment, the at least two lugs are positioned on the distal end of the handle. In one embodiment, the proximal end of the rod comprises a cavity, and the at least two grooves positioned on the inner wall of the cavity of the rod, each of the at least two grooves comprising a helical portion of which one end is a wall perpendicular to said internal wall. In one embodiment, the at least two lugs are positioned on the proximal end of the rod. In one embodiment, the distal end of the handle comprises a cavity, and the at least two grooves positioned on the internal wall of the handle cavity, each of the at least two grooves comprising a helical portion of which one end is a wall perpendicular to said internal wall. The invention also relates to a screwdriver comprising a ratchet system according to the present invention. In one embodiment, the screwdriver is a surgical screwdriver, or suitable for use in surgery, preferably in orthopedic surgery. The invention also relates to the use of the ratchet system in a device requiring control of a direction of rotation of a rod. The invention also relates to the use of the ratchet system in a screwing and/or unscrewing means. The invention also relates to the use of the ratchet system in a screwdriver, a key, or any other screwing and/or unscrewing means known to those skilled in the art. The invention also relates to the use of the ratchet system in a screwdriver suitable for use in surgery. The invention also relates to the use of the ratchet system in a screwdriver suitable for use in orthopedic surgery. The invention also relates to the use of the ratchet system in a screwdriver suitable for use in interventional radiology. The invention also relates to the use of the ratchet system in a surgical tool, a surgical screwdriver. The invention also relates to the use of the ratchet system in mechanics, carpentry or surgery. Although various embodiments have been described and illustrated, the detailed description should not be construed as being limited thereto. Various modifications can be made to the embodiments by those skilled in the art without departing from the true spirit and scope of the disclosure as defined by the claims. Embodiments Illustrating the Invention As illustrated inFIGS.1,2A and2B, the handle1includes:a handle13;a cylindrical distal end11linked to the handle13by a connection surface131extending preferably perpendicular to the axis of revolution of the cylindrical distal end11;two lugs12equally distributed around said distal end11, having rounded ends121. In the embodiments ofFIGS.2A and2Bsaid lugs12are two, and they are diametrically opposed. The lugs12extend parallel to the axis of revolution of the cylindrical distal end11. As illustrated inFIGS.3A,4A and4B, the screw rod2comprises a cylindrical rod22comprising a male distal end23and a cylindrical proximal end21. The proximal end21comprises a cavity215displaying internal walls212. Two grooves214are machined in the internal wall212of the cavity215, the two grooves214comprising a helical portion descending from the proximal end of the rod21towards the distal end23of the rod2in a clockwise direction. The cavity212further comprises two walls213perpendicular to the internal wall212of the cavity215. The screw rod2displays a contact surface aimed at cooperating with the connection surface131of the handle13. The distal end11of the handle13is configured to fit into the cavity215formed in the proximal end21of the screwing rod2. During this operation, the two lugs12are supported and slide along the two grooves.214carved into said cavity215until said lugs12are each in abutment contact with one perpendicular wall213machined in the internal wall212of the cavity215of the proximal end21of the rod2, and the connection surface131is in contact with the opposite contact surface211of the screw rod2. The walls213perpendicular to the internal wall212of the cavity215of the proximal part of the rod21are then rotated by said lugs12in the clockwise rotation direction f1, f1′. It follows that a rotational movement, and more particularly, a screwing movement, is applied to the screwing rod2. In this embodiment, when the shaft13, of the handle1is coupled with the screwing rod2and is actuated in the clockwise direction f1, meaning screwing, the lugs12of said handle1come to cooperate with the perpendicular walls213, so that the surface of the connection surface131is in abutment contact with the contact surface211, so as to drive the rod2in the same clockwise direction f1′, meaning screwing it. This embodiment is particularly advantageous because if, by an untimely gesture, said handle1is actuated in the counterclockwise direction f2, meaning unscrewing, the lugs12separate from the walls213, their ends121slide and go up on the grooves214, thus preventing the driving of the screw rod2. This embodiment is also advantageous because the distal end11of the handle1remains trapped in the cavity215, so that said handle1is not separated from the screw rod2, to allow it to be actuated again clockwise f1, meaning screwing, to drive the screwing rod2in the clockwise direction f1′, meaning screwing. As illustrated inFIGS.3B,5and6, the unscrewing rod3comprises, similarly to the screwing rod2:a cylindrical rod32comprising a male distal end33and a cylindrical proximal end31, said proximal end31comprising a cavity315;two grooves314machined in the internal walls312of the cavity315, the two grooves314comprising a helical portion descending from the proximal end31of the unscrewing rod3towards the distal end33of the unscrewing rod3in a counterclockwise direction; andtwo walls313perpendicular to the internal wall312of the cavity315. In a similar way to the screwing rod2, the distal end11of the handle13is configured to fit into a cavity315formed in the proximal end31of the unscrewing rod3. During this operation, the two lugs12are supported and slide along two grooves.314carved out in said cavity315until said lugs12are each in contact with a perpendicular wall313machined in the internal wall312of the cavity315of the proximal part of the rod, and the surface of the connection surface131is in contact with a contact surface311of the rod3. The walls313perpendicular to the internal wall312of the cavity315of the proximal part31of the unscrewing rod3are then rotated by said lugs12in the direction of anti-clockwise rotation f2, f2′. As a result, a rotational movement, and more particularly, an unscrewing movement, is applied to the unscrewing rod3. In this embodiment, when the shaft13, of the handle1is coupled with the unscrewing rod3and is actuated in the counterclockwise direction of the arrow f2, meaning unscrewing, the lugs12of said handle1cooperate with the walls313, until the surface of the connection surface131is in contact with the contact surface311, so as to drive the unscrewing rod3in the same counterclockwise direction f2′, meaning unscrewing. This embodiment is particularly advantageous because if, by an inadvertent gesture, said handle1is actuated in the clockwise direction f1, meaning screwing, the lugs12separate from the walls313, their ends121slide and go up on the grooves314, thus preventing the driving of the unscrewing rod3. This embodiment is also advantageous because the distal end11of the handle1remains trapped in the cavity315, so that said handle1is not separated from the unscrewing rod3, to allow it to be actuated by again in the counterclockwise direction f2, meaning unscrewing, to drive the unscrewing rod3in the counterclockwise direction f2′, meaning unscrewing.

11857239

DETAILED DESCRIPTION OF THE INVENTION The present invention provides improved medical devices, systems, and methods. Embodiments of the invention will facilitate remodeling of target tissues disposed at and below the skin, optionally to treat a cosmetic defect, a lesion, a disease state, and/or so as to alter a shape of the overlying skin surface, while providing protection to portions of non-target tissues, including the skin, which are directly above the target tissues. Among the most immediate applications of the present invention may be the amelioration of lines and wrinkles, particularly by inhibiting muscular contractions which are associated with these cosmetic defects so as so improve an appearance of the patient. Rather than relying entirely on a pharmacological toxin or the like to disable muscles so as to induce temporary paralysis, many embodiments of the invention will at least in part employ cold to immobilize muscles. Advantageously, nerves, muscles, and associated tissues may be temporarily immobilized using moderately cold temperatures of 10° C. to −5° C. without permanently disabling the tissue structures. Using an approach similar to that employed for identifying structures associated with atrial fibrillation, a needle probe or other treatment device can be used to identify a target tissue structure in a diagnostic mode with these moderate temperatures, and the same probe (or a different probe) can also be used to provide a longer term or permanent treatment, optionally by ablating the target tissue zone and/or inducing apoptosis at temperatures from about −5° C. to about −50° C. In some embodiments, apoptosis may be induced using treatment temperatures from about −1° C. to about −15° C., or from about −1° C. to about −19° C., optionally so as to provide a permanent treatment that limits or avoids inflammation and mobilization of skeletal muscle satellite repair cells. In some embodiments, temporary axonotmesis or neurotmesis degeneration of a motor nerve is desired, which may be induced using treatment temperatures from about −25° C. to about −90° C. Hence, the duration of the treatment efficacy of such subdermal cryogenic treatments may be selected and controlled, with colder temperatures, longer treatment times, and/or larger volumes or selected patterns of target tissue determining the longevity of the treatment. Additional description of cryogenic cooling for treatment of cosmetic and other defects may be found in commonly assigned U.S. Pat. No. 7,713,266 entitled “Subdermal Cryogenic Remodeling of Muscle, Nerves, Connective Tissue, and/or Adipose Tissue (Fat)”, U.S. Pat. No. 7,850,683 entitled “Subdermal Cryogenic Remodeling of Muscles, Nerves, Connective Tissue, and/or Adipose Tissue (Fat)”, and U.S. patent application Ser. No. 13/325,004, entitled “Method for Reducing Hyperdynamic Facial Wrinkles”, the full disclosures of which are each incorporated by reference herein. In addition to cosmetic treatments of lines, wrinkles, and the like, embodiments of the invention may also find applications for treatments of subdermal adipose tissues, benign, pre-malignant lesions, malignant lesions, acne and a wide range of other dermatological conditions (including dermatological conditions for which cryogenic treatments have been proposed and additional dermatological conditions), and the like. Embodiments of the invention may also find applications for alleviation of pain, including those associated with muscle spasms as disclosed in commonly assigned U.S. Pub. No. 2009/0248001 entitled “Pain Management Using Cryogenic Remodeling” the full disclosure of which is incorporated herein by reference. Referring now toFIGS.1A and1B, a system for cryogenic remodeling here comprises a self-contained probe handpiece generally having a proximal end12and a distal end14. A handpiece body or housing16has a size and ergonomic shape suitable for being grasped and supported in a surgeon's hand or other system operator. As can be seen most clearly inFIG.1B, a cryogenic cooling fluid supply18, a supply valve32and electrical power source20are found within housing16, along with a circuit22having a processor for controlling cooling applied by self-contained system10in response to actuation of an input24. Alternatively, electrical power can be applied through a cord from a remote power source. Power source20also supplies power to heater element44in order to heat the proximal region of probe26thereby helping to prevent unwanted skin damage, and a temperature sensor48adjacent the proximal region of probe26helps monitor probe temperature. Additional details on the heater44and temperature sensor48are described in greater detail below. When actuated, supply valve32controls the flow of cryogenic cooling fluid from fluid supply18. Some embodiments may, at least in part, be manually activated, such as through the use of a manual supply valve and/or the like, so that processors, electrical power supplies, and the like may not be required. Extending distally from distal end14of housing16is a tissue-penetrating cryogenic cooling probe26. Probe26is thermally coupled to a cooling fluid path extending from cooling fluid source18, with the exemplary probe comprising a tubular body receiving at least a portion of the cooling fluid from the cooling fluid source therein. The exemplary probe26comprises a 27 g needle having a sharpened distal end that is axially sealed. Probe26may have an axial length between distal end14of housing16and the distal end of the needle of between about 0.5 mm and 5 cm, preferably having a length from about 3 mm to about 10 mm. Such needles may comprise a stainless steel tube with an inner diameter of about 0.006 inches and an outer diameter of about 0.012 inches, while alternative probes may comprise structures having outer diameters (or other lateral cross-sectional dimensions) from about 0.006 inches to about 0.100 inches. Generally, needle probe26will comprise a 16 g or smaller size needle, often comprising a 20 g needle or smaller, typically comprising a 25, 26, 27, 28, 29, or 30 g or smaller needle. In some embodiments, probe26may comprise two or more needles arranged in a linear array, such as those disclosed in previously incorporated U.S. Pat. No. 7,850,683. Another exemplary embodiment of a probe having multiple needle probe configurations allow the cryogenic treatment to be applied to a larger or more specific treatment area. Other needle configurations that facilitate controlling the depth of needle penetration and insulated needle embodiments are disclosed in commonly assigned U.S. Patent Publication No. 2008/0200910 entitled “Replaceable and/or Easily Removable Needle Systems for Dermal and Transdermal Cryogenic Remodeling,” the entire content of which is incorporated herein by reference. Multiple needle arrays may also be arrayed in alternative configurations such as a triangular or square array. Arrays may be designed to treat a particular region of tissue, or to provide a uniform treatment within a particular region, or both. In some embodiments needle26is releasably coupled with body16so that it may be replaced after use with a sharper needle (as indicated by the dotted line) or with a needle having a different configuration. In exemplary embodiments, the needle may be threaded into the body, it may be press fit into an aperture in the body or it may have a quick disconnect such as a detent mechanism for engaging the needle with the body. A quick disconnect with a check valve is advantageous since it permits decoupling of the needle from the body at any time without excessive coolant discharge. This can be a useful safety feature in the event that the device fails in operation (e.g. valve failure), allowing an operator to disengage the needle and device from a patient's tissue without exposing the patient to coolant as the system depressurizes. This feature is also advantageous because it allows an operator to easily exchange a dull needle with a sharp needle in the middle of a treatment. One of skill in the art will appreciate that other coupling mechanisms may be used. Addressing some of the components within housing16, the exemplary cooling fluid supply18comprises a canister, sometimes referred to herein as a cartridge, containing a liquid under pressure, with the liquid preferably having a boiling temperature of less than 37° C. When the fluid is thermally coupled to the tissue-penetrating probe26, and the probe is positioned within the patient so that an outer surface of the probe is adjacent to a target tissue, the heat from the target tissue evaporates at least a portion of the liquid and the enthalpy of vaporization cools the target tissue. A supply valve32may be disposed along the cooling fluid flow path between canister18and probe26, or along the cooling fluid path after the probe so as to limit coolant flow thereby regulating the temperature, treatment time, rate of temperature change, or other cooling characteristics. The valve will often be powered electrically via power source20, per the direction of processor22, but may at least in part be manually powered. The exemplary power source20comprises a rechargeable or single-use battery. Additional details about valve32are disclosed below and further disclosure on the power source20may be found in commonly assigned Int'l Pub. No. WO 2010/075438 entitled “Integrated Cryosurgical Probe Package with Fluid Reservoir and Limited Electrical Power Source,” the entire contents of which is incorporated herein by reference. The exemplary cooling fluid supply18comprises a single-use canister. Advantageously, the canister and cooling fluid therein may be stored and/or used at (or even above) room temperature. The canister may have a frangible seal or may be refillable, with the exemplary canister containing liquid nitrous oxide, N2O. A variety of alternative cooling fluids might also be used, with exemplary cooling fluids including fluorocarbon refrigerants and/or carbon dioxide. The quantity of cooling fluid contained by canister18will typically be sufficient to treat at least a significant region of a patient, but will often be less than sufficient to treat two or more patients. An exemplary liquid N2O canister might contain, for example, a quantity in a range from about 1 gram to about 40 grams of liquid, more preferably from about 1 gram to about 35 grams of liquid, and even more preferably from about 7 grams to about 30 grams of liquid. Processor22will typically comprise a programmable electronic microprocessor embodying machine readable computer code or programming instructions for implementing one or more of the treatment methods described herein. The microprocessor will typically include or be coupled to a memory (such as a non-volatile memory, a flash memory, a read-only memory (“ROM”), a random access memory (“RAM”), or the like) storing the computer code and data to be used thereby, and/or a recording media (including a magnetic recording media such as a hard disk, a floppy disk, or the like; or an optical recording media such as a CD or DVD) may be provided. Suitable interface devices (such as digital-to-analog or analog-to-digital converters, or the like) and input/output devices (such as USB or serial I/O ports, wireless communication cards, graphical display cards, and the like) may also be provided. A wide variety of commercially available or specialized processor structures may be used in different embodiments, and suitable processors may make use of a wide variety of combinations of hardware and/or hardware/software combinations. For example, processor22may be integrated on a single processor board and may run a single program or may make use of a plurality of boards running a number of different program modules in a wide variety of alternative distributed data processing or code architectures. Referring now toFIG.2, the flow of cryogenic cooling fluid from fluid supply18is controlled by a supply valve32. Supply valve32may comprise an electrically actuated solenoid valve, a motor actuated valve or the like operating in response to control signals from controller22, and/or may comprise a manual valve. Exemplary supply valves may comprise structures suitable for on/off valve operation, and may provide venting of the fluid source and/or the cooling fluid path downstream of the valve when cooling flow is halted so as to limit residual cryogenic fluid vaporization and cooling. Additionally, the valve may be actuated by the controller in order to modulate coolant flow to provide high rates of cooling in some instances where it is desirable to promote necrosis of tissue such as in malignant lesions and the like or slow cooling which promotes ice formation between cells rather than within cells when necrosis is not desired. More complex flow modulating valve structures might also be used in other embodiments. For example, other applicable valve embodiments are disclosed in previously incorporated U.S. Pub. No. 2008/0200910. Still referring toFIG.2, an optional heater (not illustrated) may be used to heat cooling fluid supply18so that heated cooling fluid flows through valve32and through a lumen34of a cooling fluid supply tube36. Supply tube36is, at least in part, disposed within a lumen38of needle26, with the supply tube extending distally from a proximal end40of the needle toward a distal end42. The exemplary supply tube36comprises a fused silica tubular structure (not illustrated) having a polymer coating and extending in cantilever into the needle lumen38. Supply tube36may have an inner lumen with an effective inner diameter of less than about 200 μm, the inner diameter often being less than about 100 μm, and typically being less than about 40 μm. Exemplary embodiments of supply tube36have inner lumens of between about 15 and 50 μm, such as about 30 μm. An outer diameter or size of supply tube36will typically be less than about 1000 μm, often being less than about 800 μm, with exemplary embodiments being between about 60 and 150 μm, such as about 90 μm or 105 μm. The tolerance of the inner lumen diameter of supply tubing36will preferably be relatively tight, typically being about +/−10 μm or tighter, often being +/−5 μm or tighter, and ideally being +/−3 μm or tighter, as the small diameter supply tube may provide the majority of (or even substantially all of) the metering of the cooling fluid flow into needle26. Previously incorporated U.S. Patent Publication No. 2008/0200910 discloses additional details on the needle26along with various alternative embodiments and principles of operation. The cooling fluid injected into lumen38of needle26will typically comprise liquid, though some gas may also be injected. At least some of the liquid vaporizes within needle26, and the enthalpy of vaporization cools the needle and also the surrounding tissue engaged by the needle. An optional heater44(illustrated inFIG.1B) may be used to heat the proximal region of the needle26in order to prevent unwanted skin damage in this area, as discussed in greater detail below. Controlling a pressure of the gas/liquid mixture within needle26substantially controls the temperature within lumen38, and hence the treatment temperature range of the tissue. A relatively simple mechanical pressure relief valve46may be used to control the pressure within the lumen of the needle, with the exemplary valve comprising a valve body such as a ball bearing, urged against a valve seat by a biasing spring. An exemplary relief valve is disclosed in U.S. Provisional Patent Application No. 61/116,050 previously incorporated herein by reference. Thus, the relief valve allows better temperature control in the needle, minimizing transient temperatures. Further details on exhaust volume are disclosed in previously incorporated U.S. Pat. Pub. No. 2008/0200910. The heater44may be thermally coupled to a thermally responsive element50, which is supplied with power by the controller22and thermally coupled to a proximal portion of the needle26. The thermally responsive element50can be a block constructed from a material of high thermal conductivity and low heat capacity, such as aluminum. A first temperature sensor52(e.g., thermistor, thermocouple) can also be thermally coupled the thermally responsive element50and communicatively coupled to the controller22. A second temperature sensor53can also be positioned near the heater44, for example, such that the first temperature sensor52and second temperature sensor44are placed in different positions within the thermally responsive element50. In some embodiments, the second temperature sensor53is placed closer to a tissue contacting surface than the first temperature sensor is in order to provide comparative data (e.g., temperature differential) between the sensors. The controller22can be configured to receive temperature information of the thermally responsive element50via the temperature sensor52in order to provide the heater44with enough power to maintain the thermally responsive element50at a particular temperature. The controller22can be further configured to monitor power draw from the heater44in order to characterize tissue type, perform device diagnostics, and/or provide feedback for a tissue treatment algorithm. This can be advantageous over monitoring temperature alone, since power draw from the heater44can vary greatly while temperature of the thermally responsive element50remains relatively stable. For example, during treatment of target tissue, maintaining the thermally responsive element50at 40° C. during a cooling cycle may take 1.0 W initially and is normally expected to climb to 1.5 W after 20 seconds, due to the needle26drawing in surrounding heat. An indication that the heater is drawing 2.0 W after 20 seconds to maintain 40° C. can indicate that an aspect of the system10is malfunctioning and/or that the needle26is incorrectly positioned. Correlations with power draw and correlated device and/or tissue conditions can be determined experimentally to determine acceptable treatment power ranges. In some embodiments, it may be preferable to limit frozen tissue that is not at the treatment temperature, i.e., to limit the size of a formed cooling zone within tissue. Such cooling zones may be associated with a particular physical reaction, such as the formation of an ice-ball, or with a particular temperature profile or temperature volume gradient required to therapeutically affect the tissue therein. To achieve this, metering coolant flow could maintain a large thermal gradient at its outside edges. This may be particularly advantageous in applications for creating an array of connected cooling zones (i.e, fence) in a treatment zone, as time would be provided for the treatment zone to fully develop within the fenced in portion of the tissue, while the outer boundaries maintained a relatively large thermal gradient due to the repeated application and removal of refrigeration power. This could provide a mechanism within the body of tissue to thermally regulate the treatment zone and could provide increased ability to modulate the treatment zone at a prescribed distance from the surface of the skin. A related treatment algorithm could be predefined, or it could be in response to feedback from the tissue. Such feedback could be temperature measurements from the needle26, or the temperature of the surface of the skin could be measured. However, in many cases monitoring temperature at the needle26is impractical due to size constraints. To overcome this, operating performance of the sensorless needle26can be interpolated by measuring characteristics of thermally coupled elements, such as the thermally responsive element50. One such measured characteristic could be the power required to heat the thermally responsive element50, therefore the medium which the thermally responsive element50, or the thermally coupled needle26, is coupled to. For example, very little power would be required to warm and maintain the temperature of the thermally conductive element50in air. Various materials could be characterized. For example, the thermally responsive element50could be used to determine whether the thermally responsive element50, or the thermally coupled needle26, has sufficient contact with skin due to the thermal load of the skin. This would be useful for ensuring that the needle26was correctly placed prior to treatment. This could be done without flowing coolant to the needle26, or alternatively, by metering very little coolant to the needle26, i.e., less than what is required to treat tissue. Once the treatment has started, there may be more or less residual refrigerant that affected the thermally conductive element50depending upon how much thermal load was applied to the needle26. This could be used to characterize the tissue(s) the probes was placed into. For example, there would be relatively more heat drawn from the thermally conductive element50in insulative tissue such as adipose tissue. Since thermal load on the distal end of the needle26would be affected by the development of an cooling zone around the needle26, the thermally conductive element50could be used to determine the state of the needle26as ice forms. Power feedback could provide feedback to regulate the delivery of refrigerant based upon the tissue, formation of ice, contact with the skin, or other useful information. The feedback could be used to control the treatment zone to the desired configuration. In addition, the feedback could be used to diagnose a treatment failure. For instance if the probe had three needles delivering refrigerant, but only two were working, the thermally conductive element could detect the failure and inform the user. Temperature feedback could also used in conjunction with power feedback. Temperature sensing could occur on the needle26if possible, on the thermally conductive element50, and/or remote to the thermally conductive element. For example, the thermally conductive element50could reside on a detachable cooling probe and be thermally coupled to a handpiece, with feedback and control circuits located within the handpiece (e.g., housing16). This could be advantageous to provide a low cost detachable cooling probe and for system reliability, since the probe could be coupled to a controller in the reusable handpiece. Thus, practically offering higher capability due to the ability to afford more precise controls. The thermally conductive element50could be thermally coupled to the needle26at a proximal tissue interface. When refrigerant was delivered, excess refrigerant would return through the needle. The excess refrigerant could be in the form of cool gas or liquid that had not yet converted to gas through the latent heat of vaporization. The excess refrigerant could change dependent upon the tissue(s) the probe was in, variations in tissue temperature, presence of local heat sources (arteries and veins), and metabolic effects. The excess refrigerant could also be affected by the effect of the treatment over time. In particular, changes in thermal loading as a function of the cooling of adjacent tissue and the formation of ice. The thermally conductive element could be tailored to deliver comparable, or more heat than the available refrigeration power. However, the transfer of heat into the tissue would be constrained by the material and dimensions of the needle. For example, a relatively long needle might receive enough heat from the adjacent tissue along its length to prevent the freeze zone from extending more proximally than desired. Alternatively the ability to transfer more heat into the tissue could be achieved by providing improved thermal coupling from the thermally conductive element50into the tissue. This could be achieved by increasing the diameter and or wall thickness of the needle, or through the addition of thermally conductive cladding to the proximal portion of the needle. This coupling could also be optimized to extend the length of the protection desired. For instance, the cladding or portion of increased wall thickness and diameter could extend through the dermis and subdermal fat layer, then end. Further the cooling of the tip and the heating of more proximal tissue could be uncoupled. This could be achieved by applying an insulative material between the cladding and the underlying needle. Therefore, the heat through the protected portion of tissue could be controlled independent of the refrigeration of the tip. This would be advantageous in that the heat added would not compromise the refrigerant delivered to the tip and the refrigerant would not comprise the heat added to the tissue. Additional methods of monitoring cooling and maintaining an unfrozen portion of the needle include the addition of a heating element and/or monitoring element into the needle itself. This could consist of a small thermistor or thermocouple, and a wire that could provide resistive heat. Other power sources could also be applied such as infrared light, radiofrequency heat, and ultrasound. These systems could also be applied together dependent upon the control of the treatment zone desired. Alternative methods to inhibit excessively low transient temperatures at the beginning of a refrigeration cycle might be employed instead of or together with the limiting of the exhaust volume. For example, the supply valve might be cycled on and off, typically by controller22, with a timing sequence that would limit the cooling fluid flowing so that only vaporized gas reached the needle lumen (or a sufficiently limited amount of liquid to avoid excessive dropping of the needle lumen temperature). This cycling might be ended once the exhaust volume pressure was sufficient so that the refrigeration temperature would be within desired limits during steady state flow. Analytical models that may be used to estimate cooling flows are described in greater detail in previously incorporated U.S. Patent Pub. No. 2008/0154,254. Referring now toFIG.2, the flow of cryogenic cooling fluid from fluid supply18is controlled by a supply valve32. Supply valve32may comprise an electrically actuated solenoid valve, a motor actuated valve or the like operating in response to control signals from controller22, and/or may comprise a manual valve. Exemplary supply valves may comprise structures suitable for on/off valve operation, and may provide venting of the fluid source and/or the cooling fluid path downstream of the valve when cooling flow is halted so as to limit residual cryogenic fluid vaporization and cooling. Additionally, the valve may be actuated by the controller in order to modulate coolant flow to provide high rates of cooling in some instances where it is desirable to promote necrosis of tissue such as in malignant lesions and the like or slow cooling which promotes ice formation between cells rather than within cells when necrosis is not desired. More complex flow modulating valve structures might also be used in other embodiments. For example, other applicable valve embodiments are disclosed in previously incorporated U.S. Pub. No. 2008/0200910. Still referring toFIG.2, an optional cooling supply heater (not illustrated) may be used to heat cooling fluid supply18so that heated cooling fluid flows through valve32and through a lumen34of a cooling fluid supply tube36. In some embodiments safety mechanism can be included so that the cooling supply is not overheated. Examples of such embodiments are disclosed in commonly assigned Int'l. Pub. No. WO 2010075438, the entirety of which is incorporated by reference herein. Supply tube36is, at least in part, disposed within a lumen38of needle26, with the supply tube extending distally from a proximal end40of the needle toward a distal end42. The exemplary supply tube36comprises a fused silica tubular structure (not illustrated) having a polymer coating and extending in cantilever into the needle lumen38. Supply tube36may have an inner lumen with an effective inner diameter of less than about 200 μm, the inner diameter often being less than about 100 μm, and typically being less than about 40 μm. Exemplary embodiments of supply tube36have inner lumens of between about 15 and 50 μm, such as about 30 μm. An outer diameter or size of supply tube36will typically be less than about 1000 μm, often being less than about 800 μm, with exemplary embodiments being between about 60 and 150 μm, such as about 90 μm or 105 μm. The tolerance of the inner lumen diameter of supply tubing36will preferably be relatively tight, typically being about +/−10 μm or tighter, often being +/−5 μm or tighter, and ideally being +/−3 μm or tighter, as the small diameter supply tube may provide the majority of (or even substantially all of) the metering of the cooling fluid flow into needle26. Additional details on various aspects of needle26along with alternative embodiments and principles of operation are disclosed in greater detail in U.S. Patent Publication No. 2008/0154254 entitled “Dermal and Transdermal Cryogenic Microprobe Systems and Methods,” the entire contents of which are incorporated herein by reference. U.S. Patent Pub. No. 2008/0200910, previously incorporated herein by reference, also discloses additional details on the needle26along with various alternative embodiments and principles of operation. The cooling fluid injected into lumen38of needle26will typically comprise liquid, though some gas may also be injected. At least some of the liquid vaporizes within needle26, and the enthalpy of vaporization cools the needle and also the surrounding tissue engaged by the needle. An optional heater44(illustrated inFIG.1B) may be used to heat the proximal region of the needle in order to prevent unwanted skin damage in this area, as discussed in greater detail below. Controlling a pressure of the gas/liquid mixture within needle26substantially controls the temperature within lumen38, and hence the treatment temperature range of the tissue. A relatively simple mechanical pressure relief valve46may be used to control the pressure within the lumen of the needle, with the exemplary valve comprising a valve body such as a ball bearing, urged against a valve seat by a biasing spring. Thus, the relief valve allows better temperature control in the needle, minimizing transient temperatures. Further details on exhaust volume are disclosed in U.S. Patent Publication No. 2008/0200910, previously incorporated herein by reference. Alternative methods to inhibit excessively low transient temperatures at the beginning of a refrigeration cycle might be employed instead of or together with the limiting of the exhaust volume. For example, the supply valve might be cycled on and off, typically by controller22, with a timing sequence that would limit the cooling fluid flowing so that only vaporized gas reached the needle lumen (or a sufficiently limited amount of liquid to avoid excessive dropping of the needle lumen temperature). This cycling might be ended once the exhaust volume pressure was sufficient so that the refrigeration temperature would be within desired limits during steady state flow. Analytical models that may be used to estimate cooling flows are described in greater detail in U.S. Pub. No. 2008/0154254, previously incorporated herein by reference. In the exemplary embodiment ofFIG.3A, resistive heater element314is disposed near the needle hub318and near a proximal region of needle shaft302. The resistance of the heater element is preferably 1Ω to 1KΩ, and more preferably from 5Ω to 50Ω. Additionally, a temperature sensor312such as a thermistor or thermocouple is also disposed in the same vicinity. Thus, during a treatment as the needles cool down, the heater314may be turned on in order to heat the hub318and proximal region of needle shaft302, thereby preventing this portion of the device from cooling down as much as the remainder of the needle shaft302. The temperature sensor312may provide feedback to controller22and a feedback loop can be used to control the heater314. The cooling power of the nitrous oxide will eventually overcome the effects of the heater, therefore the microprocessor may also be programmed with a warning light and/or an automatic shutoff time to stop the cooling treatment before skin damage occurs. An added benefit of using such a heater element is the fact that the heat helps to moderate the flow of cooling fluid into the needle shaft302helping to provide more uniform coolant mass flow to the needles shaft302with more uniform cooling resulting. The embodiment ofFIG.3Aillustrates a heater fixed to the probe hub. In other embodiments, the heater may float, thereby ensuring proper skin contact and proper heat transfer to the skin. Examples of floating heaters are disclosed in commonly assigned Int'l Pub. No. WO 2010/075448 entitled “Skin Protection for Subdermal Cyrogenic Remodelling for Cosmetic and Other Treatments”, the entirety of which is incorporated by reference herein. In this exemplary embodiment, three needles are illustrated. One of skill in the art will appreciate that a single needle may be used, as well as two, four, five, six, or more needles may be used. When a plurality of needles are used, they may be arranged in any number of patterns. For example, a single linear array may be used, or a two dimensional or three dimensional array may be used. Examples of two dimensional arrays include any number of rows and columns of needles (e.g. a rectangular array, a square array, elliptical, circular, triangular, etc.), and examples of three dimensional arrays include those where the needle tips are at different distances from the probe hub, such as in an inverted pyramid shape. FIG.3Billustrates a cross-section of the needle shaft302of needle probe300. The needle shaft can be conductively coupled (e.g., welded, conductively bonded, press fit) to a conductive heater314to enable heat transfer therebetween. The needle shaft302is generally a small (e.g., 20-30 gauge) closed tip hollow needle, which can be between about 0.2 mm and 5 cm, preferably having a length from about 0.3 cm to about 0.6 cm. The conductive heater element314can be housed within a conductive block315of high thermally conductive material, such as aluminum and include an electrically insulated coating, such as Type III anodized coating to electrically insulate it without diminishing its heat transfer properties. The conductive block315can be heated by a resister or other heating element (e.g. cartridge heater, nichrome wire, etc.) bonded thereto with a heat conductive adhesive, such as epoxy. A thermistor can be coupled to the conductive block315with heat conductive epoxy allows temperature monitoring. Other temperature sensors may also be used, such as a thermocouple. A cladding320of conductive material is directly conductively coupled to the proximal portion of the shaft of needle shaft302, which can be stainless steel. In some embodiments, the cladding320is a layer of gold, or alloys thereof, coated on the exterior of the proximal portion of the needle shaft302. In some embodiments, the exposed length of cladding320on the proximal portion of the needle is 2 mm. In some embodiments, the cladding320be of a thickness such that the clad portion has a diameter ranging from 0.017-0.020 in., and in some embodiments 0.0182 in. Accordingly, the cladding320can be conductively coupled to the material of the needle302, which can be less conductive, than the cladding320. In some embodiments, the cladding320can include sub-coatings (e.g., nickel) that promote adhesion of an outer coating that would otherwise not bond well to the needle shaft302. Other highly conductive materials can be used as well, such as copper, silver, aluminum, and alloys thereof. In some embodiments, a protective polymer or metal coating can cover the cladding to promote biocompatibility of an otherwise non-biocompatible but highly conductive cladding material. Such a biocompatible coating however, would be applied to not disrupt conductivity between the conductive block315. In some embodiments, an insulating layer, such as a ceramic material, is coated over the cladding320, which remains conductively coupled to the needle shaft302. In use, the cladding320can transfer heat to the proximal portion of the needle302to prevent directly surrounding tissue from dropping to cryogenic temperatures. Protection can be derived from heating the non-targeting tissue during a cooling procedure, and in some embodiments before the procedure as well. The mechanism of protection may be providing latent heat to pressurized cryogenic cooling fluid passing within the proximal portion of the needle to affect complete vaporization of the fluid. Thus, the non-target tissue in contact with the proximal portion of the needle shaft302does not need to supply latent heat, as opposed to target tissue in contact with the distal region of the needle shaft302. To help further this effect, in some embodiments the cladding320is coating within the interior of the distal portion of the needle, with or without an exterior cladding. To additionally help further this effect, in some embodiments, the distal portion of the needle can be thermally isolated from the proximal portion by a junction, such as a ceramic junction. While in some further embodiments, the entirety of the proximal portion is constructed from a more conductive material than the distal portion. In use, it has been determined experimentally that the cladding320can help limit formation of an cooling zone to the distal portion of the needle shaft302, which tends to demarcate at a distal end of the cladding320. This effect is shown depicted inFIG.3Cwhere non-target tissue, directly above target tissue, including skin and at least a portion of subcutaneous tissue are not made part of the ice-ball. Rather, cooling zones are formed only about the distal portions of the needles—in this case to target a temporal nerve branch. Thus, while non-target tissue in direct contact with proximal needle shafts remain protected from effects of cryogenic temperatures. Such effects can include discoloration and blistering of the skin. An exemplary algorithm400for controlling the heater element314, and thus for transferring heat to the cladding320, is illustrated inFIG.4. InFIG.4, the start of the interrupt service routine (ISR)402begins with reading the current needle hub temperature404using a temperature sensor such as a thermistor or thermocouple disposed near the needle hub. The time of the measurement is also recorded. This data is fed back to controller22where the slope of a line connecting two points is calculated. The first point in the line is defined by the current needle hub temperature and time of its measurement and the second point consists of a previous needle hub temperature measurement and its time of measurement. Once the slope of the needle hub temperature curve has been calculated406, it is also stored408along with the time and temperature data. The needle hub temperature slope is then compared with a slope threshold value410. If the needle hub temperature slope is less than the threshold value then a treating flag is activated412and the treatment start time is noted and stored414. If the needle hub slope is greater than or equal to the slope threshold value410, an optional secondary check416may be used to verify that cooling has not been initiated. In step416, absolute needle hub temperature is compared to a temperature threshold. If the hub temperature is less than the temperature threshold, then the treating flag is activated412and the treatment start time is recorded414as previously described. As an alternative, the shape of the slope could be compared to a norm, and an error flag could be activated for an out of norm condition. Such a condition could indicate the system was not heating or cooling sufficiently. The error flag could trigger an automatic stop to the treatment with an error indicator light. Identifying the potential error condition and possibly stopping the treatment, may prevent damage to the proximal tissue in the form of too much heat, or too much cooling to the tissue. The algorithm preferably uses the slope comparison as the trigger to activate the treatment flag because it is more sensitive to cooling conditions when the cryogenic device is being used rather than simply measuring absolute temperature. For example, a needle probe exposed to a cold environment would gradually cool the needle down and this could trigger the heater to turn on even though no cryogenic cooling treatment was being conducted. The slope more accurately captures rapid decreases in needle temperature as are typically seen during cryogenic treatments. When the treatment flag is activated418the needle heater is enabled420and heater power may be adjusted based on the elapsed treatment time and current needle hub temperature422. Thus, if more heat is required, power is increased and if less heat is required, power is decreased. Whether the treatment flag is activated or not, as an additional safety mechanism, treatment duration may be used to control the heater element424. As mentioned above, eventually, cryogenic cooling of the needle will overcome the effects of the heater element. In that case, it would be desirable to discontinue the cooling treatment so that the proximal region of the probe does not become too cold and cause skin damage. Therefore, treatment duration is compared to a duration threshold value in step424. If treatment duration exceeds the duration threshold then the treatment flag is cleared or deactivated426and the needle heater is deactivated428. If the duration has not exceeded the duration threshold424then the interrupt service routine ends430. The algorithm then begins again from the start step402. This process continues as long as the cryogenic device is turned on. Preferred ranges for the slope threshold value may range from about −5° C. per second to about −90° C. per second and more preferably range from about −30° C. per second to about −57° C. per second. Preferred ranges for the temperature threshold value may range from about 15° C. to about 0° C., and more preferably may range from about 0° C. to about 10° C. Treatment duration threshold may range from about 15 seconds to about 75 seconds and more preferably may range from about 15 seconds to about 60 seconds. It should be appreciated that the specific steps illustrated inFIG.4provide a particular method of heating a cryogenic probe, according to an embodiment of the present invention. Other sequences of steps may also be performed according to alternative embodiments. For example, alternative embodiments of the present invention may perform the steps outlined above in a different order. Moreover, the individual steps illustrated inFIG.4may include multiple sub-steps that may be performed in various sequences as appropriate to the individual step. Furthermore, additional steps may be added or removed depending on the particular applications. One of ordinary skill in the art would recognize many variations, modifications, and alternatives. The heating algorithm may be combined with a method for treating a patient. Referring now toFIG.5, a method100facilitates treating a patient using a cryogenic cooling system having a reusable or disposable handpiece either of which that can be self-contained or externally powered with replaceable needles such as those ofFIG.1Band a limited capacity battery or metered electrical supply. Method100generally begins with a determination110of the desired tissue therapy and results, such as the alleviation of specific cosmetic wrinkles of the face, the inhibition of pain from a particular site, the alleviation of unsightly skin lesions or cosmetic defects from a region of the face, or the like. Appropriate target tissues for treatment are identified112(such as the subdermal muscles that induce the wrinkles, a tissue that transmits the pain signal, or the lesion-inducing infected tissues), allowing a target treatment depth, target treatment temperature profile, or the like to be determined. Step112may include performing a tissue characterization and/or device diagnostic algorithm, based on power draw of system10, for example. The application of the treatment algorithm114may include the control of multiple parameters such as temperature, time, cycling, pulsing, and ramp rates for cooling or thawing of treatment areas. In parallel with the treatment algorithm114, one or more power monitoring algorithms115can be implemented. An appropriate needle assembly can then be mounted116to the handpiece, with the needle assembly optionally having a needle length, skin surface cooling chamber, needle array, and/or other components suitable for treatment of the target tissues. Simpler systems may include only a single needle type, and/or a first needle assembly mounted to the handpiece. Pressure, heating, cooling, or combinations thereof may be applied118to the skin surface adjacent the needle insertion site before, during, and/or after insertion120and cryogenic cooling122of the needle and associated target tissue. Non-target tissue directly above the target tissue can be protected by directly conducting energy in the form of heat to the cladding on a proximal portion of the needle shaft during cooling. Upon completion of the cryogenic cooling cycle the needles will need additional “thaw” time123to thaw from the internally created cooling zone to allow for safe removal of the probe without physical disruption of the target tissues, which may include, but not be limited to nerves, muscles, blood vessels, or connective tissues. This thaw time can either be timed with the refrigerant valve shut-off for as short a time as possible, preferably under 15 seconds, more preferably under 5 seconds, manually or programmed into the controller to automatically shut-off the valve and then pause for a chosen time interval until there is an audible or visual notification of treatment completion. Heating of the needle may be used to prevent unwanted skin damage using the apparatus and methods previously described. The needle can then be retracted124from the target tissue. If the treatment is not complete126and the needle is not yet dull128, pressure and/or cooling can be applied to the next needle insertion location site118, and the additional target tissue treated. However, as small gauge needles may dull after being inserted only a few times into the skin, any needles that are dulled (or otherwise determined to be sufficiently used to warrant replacement, regardless of whether it is after a single insertion, 5 insertions, or the like) during the treatment may be replaced with a new needle116before the next application of pressure/cooling118, needle insertion120, and/or the like. Once the target tissues have been completely treated, or once the cooling supply canister included in the self-contained handpiece is depleted, the used canister and/or needles can be disposed of130. The handpiece may optionally be discarded. As discussed with reference toFIG.5, a power monitoring algorithm115can be applied prior to, during, after, and in some cases in lieu of, the treatment algorithm114, such as the one shown inFIG.4. One example of a power monitoring algorithm600is shown inFIG.6A, which illustrates a method for monitoring power demand from a heater when cooling fluid is passed through at least one needle. The power monitoring algorithm600can be performed during an actual treatment of tissue. At operation602, the controller (e.g., controller22) monitors power consumption of a heater (e.g., heater44), which is thermally coupled to a needle (e.g., needle26), directly or via a thermally responsive element (e.g., element50). Monitoring can take place during a tissue treatment procedure, for example, as discussed with reference toFIG.5, performed in parallel to a treatment algorithm. Alternatively, power monitoring can take place during a diagnostic routine. At operation604, the controller correlates a sampled power measurement with an acceptable power range corresponding to a tissue characteristic and/or operating parameter. This measurement may further be correlated according to the time of measurement and temperature of the thermally responsive element50. For example, during treatment of target tissue, maintaining the thermally responsive element50at 40° C. during a cooling cycle may be expected to require 1.0 W initially and is expected to climb to 1.5 W after 20 seconds, due to the needle26drawing in surrounding heat. An indication that the heater is drawing 2.0 W after 20 seconds to maintain 40° C. can indicate that an aspect of the system10is malfunctioning and/or that the needle26is incorrectly positioned within target tissue or primarily positioned in non-target tissue. Correlations with power draw and correlated device and/or tissue conditions can be determined experimentally to determine acceptable power ranges. At operation606, the controller determines whether the power measurement is correlated within acceptable limits of an expected power draw, or to a power draw indicating a tissue or device problem. Based on this, a status indication can be provided to the user. If the correlation is unacceptable, then the controller may in operation608initiate an alarm to the user and/or halt or modify the treatment algorithm. In some cases, the error is minor, for example, the controller may signal a user indication to modify operator technique, e.g., apply greater or lesser pressure to the skin, or that the needle probe is not fully inserted or that a tissue tent is present. In other cases, the error can indicate a major valve malfunction, and signal an alert to abort the process and/or cause a secondary or purge valve to operate. If the correlation is acceptable, then in operation610it is determined whether the treatment algorithm is still in process, which will cause the power monitoring algorithm to end or continue to loop. Alternatively, the power monitoring algorithm600can simply loop until interrupted by the controller, for example, when treatment algorithm has ended or by some other trigger. In some embodiments, the power monitoring algorithm600can be performed exclusively for tissue characterization purposes, e.g., to determine proper operating parameters for a later treatment, by only looping between operations602and604for a predetermined amount of time to collect data. Data can be collected and correlated by the controller to a particular tissue type and further correlated to optimal treatment parameters. For example, the characterized tissue may have a greater or lesser average amount of adjacent adipose tissue, which could require longer or shorter treatment times. This process could be performed, for example, by inserting the needle into the target tissue and providing only enough coolant to characterize the tissue, rather than remodel. FIGS.6B and6Cshow another power monitoring algorithm612for regulating a freeze zone, that can be implemented parallel to or in lieu of a treatment algorithm, such as the one shown inFIG.4, as well as parallel to another power monitoring algorithm, such as the one shown inFIG.6A. At operation614, a valve626is or has been previously regulated to provide at least one needle with coolant, with the needle being in contact with tissue, as illustrated inFIG.6C. After some time, a cooling zone628forms within the tissue, and will continue to grow in size as long as the needle is supplied with coolant from coolant supply630. Ideally, cooling zone628is limited in size to the area of target tissue632, to prevent unintentional treatment of non-target tissue634. While coolant is flowing, power demand from the heater is monitored, which can occur immediately or alternatively after a predetermined amount of time has passed since opening of valve626. At operation618, controller636determines whether a sampled power measurement correlates to a maximum ice-ball size desired for a particular therapeutic effect, such as tissue remodeling. Correlations with power draw and cooling zone size can be determined experimentally to determine acceptable power ranges, and the tissue can be pre-characterized according to a tissue characterization algorithm, such as shown inFIG.6AThis measurement may further be correlated according to the time of measurement and temperature of thermally responsive element638. If the power draw does not correlate with the maximum allowable ice-ball size, then the monitoring is continued. After a determination that the power demand correlates with the maximum cooling zone size, valve626is regulated to provide the needle with less or no coolant at operation620. After some time cooling zone628will decrease in size as heat is drawn in from surrounding tissue. During that time, power supplied to the heater is monitored at operation622. At operation624, controller636determines whether a sampled power measurement correlates to a minimum ice-ball size required to maintain the desired therapeutic effect. If the power draw does not correlate with the maximum allowable ice-ball size, then the monitoring is continued while cooling zone628continues to decrease in size. Eventually, at operation624, the power measurement will correspond with the minimum cooling zone size. This causes controller636to loop the process and provide more coolant, which causes cooling zone628to grow in size. Valve626can be metered in this manner to maintain cooling zone628within acceptable cooling zone size tolerances (e.g., between lower tolerance640and upper tolerance642), until the procedure is complete. The methods disclosed herein involve correlating measured parameters to tissue characteristics. An important tissue characteristic is its ability to transfer heat into needle probe(s), or its overall heat transfer rate. The heat transfer rate is a function of the material properties of the tissue (e.g., the thermal conductivity (or the thermal diffusivity which is a function of the thermal conductivity), tissue density, and specific heat capacity) as well as the heat transfer surface area. Confirming that the cryoprobe is fully inserted into the tissue is important because it confirms that the cooling zone is in the target tissue. A partially inserted cryoprobe can mean that the cryoprobe is within non-target tissue, such as the skin, and thus could cause injury to such non-target tissues. The controller can monitor the power to the heater and detect conditions when the thermally conductive element on the proximal end is not in sufficient thermal contact with the skin to provide protection. This occurs when the skin ‘tents’ around the shoulder of the thermally conductive element along the needle which limits to some extent the conductive path between the thermally conductive element and skin. When insufficient contact is detected the controller can terminate treatment to reduce possible tissue injury. The controller may also prevent the start of treatment until adequate contact is detected between the skin and thermally conductive element. Steady state heat transfer between the needle probe(s) and the skin can be described by the following equation q=UAΔT where q is the heat transfer rate, U is the overall heat transfer coefficient, A is the heat transfer area and ΔT is the temperature difference heater block and the skin. The tissue characteristics (including thermal conductivity and thermal diffusivity) are embodied in U and the contacting surface area is also important. It should be noted that this equation describes the steady state heat transfer, however transient conduction includes the same parameters and can be characterized in an analogous manner. To correlate the relative effectiveness of the heat transfer between the cryoprobe and the tissue, the valve can be opened momentarily to allow cooling of tissue. The temperature change of the heater block could then be monitored over time. A greater temperature change of the heater block indicates lower heat transfer between the tissue and the cryoprobe; a smaller temperature change of the heater block indicates a higher heat transfer rate. Lower heat transfer levels could be correlated with lower thermal conductivity levels or lower thermal diffusivity levels such as occurs when the needle is inserted in fat. Higher heat transfer rates could be correlated with higher thermal conductivity or thermal diffusivity such as occurs when the needles is inserted in muscle. Lower heat transfer levels could also be correlated with less heat transfer surface area. Since the total contacting surface area of the probe is known, heat transfer rates for a fully inserted needle probe(s) can be characterized. The parameter can be measured when the needle probe is first inserted into the patient tissue to determine whether the needle probe is fully inserted such that the entirety or a predetermined portion of the needle probe is embedded within tissue. In some embodiments, the tissue characterization process can include turning on the heater and opening the valve. Alternately the heater can be momentarily powered without opening the valve and without cooling. Parameters that can be correlated to tissue characteristics include heater power, the time rate of temperature change of any of a number of temperature sensors, or the instantaneous temperature differential between two temperature sensors (e.g., sensors52/53) as described below. A temperature T1of a first location and a temperature T2of a second location of the probe, e.g, locations of spacially separated sensors52/53can be measured to estimate the heat flux rate described by the equation q″=(T2−T1)*k/l, where q″ is the heat flux, T2−T1is the temperature difference, k is the thermal conductivity of the heater block and l is the distance between the two sensors. As disclosed above, higher heat flux rates indicate more heat transfer into the tissue. Alternately, electrical resistance can be measured between the sensors to confirm that the heater block is in contact with the skin. A variety of target treatment temperatures, times, and cycles may be applied to differing target tissues so as to achieve the desired remodeling. For example, as more fully described in U.S. Patent Publication Nos. 2007/0129714 and 2008/0183164, both previously incorporated herein by reference. There is a window of temperatures where apoptosis can be induced. An apoptotic effect may be temporary, long-term (lasting at least weeks, months, or years) or even permanent. While necrotic effects may be long term or even permanent, apoptosis may actually provide more long-lasting cosmetic benefits than necrosis. Apoptosis may exhibit a non-inflammatory cell death. Without inflammation, normal muscular healing processes may be inhibited. Following many muscular injuries (including many injuries involving necrosis), skeletal muscle satellite cells may be mobilized by inflammation. Without inflammation, such mobilization may be limited or avoided. Apoptotic cell death may reduce muscle mass and/or may interrupt the collagen and elastin connective chain. Temperature ranges that generate a mixture of apoptosis and necrosis may also provide long-lasting or permanent benefits. For the reduction of adipose tissue, a permanent effect may be advantageous. Surprisingly, both apoptosis and necrosis may produce long-term or even permanent results in adipose tissues, since fat cells regenerate differently than muscle cells. While the exemplary embodiments have been described in some detail for clarity of understanding and by way of example, a number of modifications, changes, and adaptations may be implemented and/or will be obvious to those as skilled in the art. Hence, the scope of the present invention is limited solely by the claims as follows.

11857240

DETAILED DESCRIPTION The disclosure relates generally to protection of cryosurgical probes from damage during a tissue ablation protocol that includes the generation of products of electrolysis. In particular, the tissue ablation protocol may involve a targeted cooling thermal surgical procedure and the products of electrolysis. The products of electrolysis may be generated before, during, and/or after the process of cryosurgery and/or cooling. Minimally invasive tissue ablation procedures are commonly used in medicine. Ablation may generally refer to the cessation of biological viability. Ablation surgeries may employ various biophysical phenomena that ablate cells and tissues and various devices and technologies that can generate the ablation biophysical phenomena. Cell ablation may be performed through thermal ablation treatment. For example, temperatures above physiological temperature may be used for cell ablation. Heat treatment may be accomplished through the delivery of radiofrequency energy, microwave energy, Joule heating energy, laser energy, ultrasound energy, and combinations thereof to the target tissue sites. Temperatures below physiological temperature may be used for cell ablation. Cooling treatment may be accomplished cooling probes at the target tissue sites. Cryosurgery is one example of a thermal cooling cell ablation technology. Cryosurgery involves the use of a device, for example, a cryosurgical probe, that removes energy and thereby generate temperatures near or below the freezing temperature of the tissue at the target tissue site. Non-invasive medical imaging can be employed with thermal ablation treatments to monitor the extent of heating or freezing in real time. Real time imaging may provide additional control over the thermal treatment. Non-thermal ablation technologies include electrolysis and electroporation. Tissue ablation by electrolysis generally involves the passage of electrical currents between a pair of electrodes and the tissue. The process of electrolysis occurs at the electrode surface in contact with an ionic solution. During electrolysis, typically, new chemical species are generated at the interface between the electrodes and the ionic solution as a result of the electrical potential driven transfer between the electrons and ions and atoms at the electrode. The products of electrolysis may diffuse from the electrodes by thermal diffusion and electro osmosis. Tissue ablation may be caused by development of a cytotoxic environment due to local changes in pH and/or the generation of products of electrolysis at the electrode surface. Electroporation typically involves electric pulses which permeabilize the cell membrane and thereby cause cell death. Tissue ablation may be caused by non-reversible permeabilization of the cell membrane and/or the entry of toxic compounds into the membrane permeabilized cell. Electroporation, which involves the passing of an electric current from electrodes to tissue, may also generate products of electrolysis. Tissue ablation procedures that combine electroporation with electrolysis (purposefully or inadvertently) may also be employed. The combined effect of electroporation and electrolysis may enhance the ablation. Certain ablation procedures combine electrolysis (either from an electrolysis procedure or generated by an electroporation procedure) with cold thermal ablation, for example, cryosurgery. Such procedures may be employed to augment cell death in the subfreezing region of tissue, where cells may be frozen but survive the cryosurgery. However, the products of electrolysis may cause damage to cryosurgical probes, potentially jeopardizing the safety of the user and the patient. Methods and devices that inhibit or reduce damage to cryosurgical probes when contacted with products of electrolysis are disclosed herein. Thus, the methods, systems, and devices disclosed herein may protect cryosurgery probes from damage during a tissue ablation procedure which includes a combination of cold thermal ablation and an electric process that generates products of electrolysis. In accordance with one aspect, there is provided a cryosurgical instrument for performing cryoelectrolysis. The cryosurgical instrument may comprise a cryosurgical probe configured to deliver a cryosurgical treatment to a target tissue. The cryosurgical probe is a device capable of bringing the target tissue to a desired cold temperature. In general, the cryosurgical probe may operate by bringing its external surface to a target temperature. The external surface may be brought into contact with the target tissue to be cooled, for example, ablated. The freezing may propagate from the part of the cryosurgical probe at subfreezing temperatures outward into the tissue. FIG.2is a schematic drawing of an exemplary cryosurgical probe220in tissue10and the tissue ice ball255(cooled region at sub-physiological temperatures) that forms around the cryosurgical probe220. The cryosurgical probe may be thermally conductive. In some embodiments, the cryosurgical probe may comprise one portion that is thermally conductive260(i.e., not thermally insulated) which extracts the energy from the tissue10, and one portion that is thermally insulated265. Formation of the ice ball255in tissue is confined to the vicinity of the thermally conductive portion260. The cryosurgical probe may be configured to perform cryosurgical ablation. The cryosurgical probe may include one or more probes through which a cryogen is internally circulated to cool the probe. Thermal conduction of the cryogen through the probe wall may operate to cool the target tissue when the probe is placed in contact with the target tissue. Cryosurgical probes may bring their external surface to a target temperature by a variety of methods. Typically, the cooling of the cryosurgical probe may be done by circulating a pressurized fluid (gas or liquid) through the cryosurgical probe. Certain cryosurgical probes may be cooled by boiling off a cryogen. Other cryosurgical probes may be cooled by Joule Thomson expansion of high-pressure gases. In general, the interior volume of the cryosurgery probe may be at an elevated pressure, for example, during cooling. The cryosurgical probe may generally include a shaft with a sharp or blunt tip. The cryosurgical probe may be dimensioned for parenteral use. For example, the cryosurgery probe may be thin. The cryosurgery probe may be structured for parenteral use. For example, the cryosurgery probe may be substantially rigid for convenience of insertion inside the body. An exemplary cryosurgical probe is distributed by Endocare, Healtronics™ (Irvine, CA). Other exemplary cryosurgical probes are distributed by Galil Medical, BTG International (London, UK). The cryosurgical probe may have an outer diameter of between about 1.5 mm and 4.0 mm, for example, about 1.5 mm, about 1.7 mm, about 2.1 mm, about 2.4 mm, and about 3.8 mm. cryoprobes have diameters of 1.5 mm, 2.1 mm and 2.4 mm. The cryosurgical probe may be formed of a biocompatible material. The cryosurgical probe may be formed of a material with mechanical properties that, at cryogenic temperatures, may withstand pressures which develop inside the cryosurgical probes. The breach of the cryosurgical probe inside the body can be fatal. The cryosurgical probe may be formed of a material which allows good heat transfer. In some embodiments, the cryosurgical probe may be formed of stainless steel. Exemplary materials include stainless steel #304 (0Cr18Ni9) and stainless steel #316 (0Cr17Ni12Mo2). The cryosurgical probe may be a single-use cryosurgical probe. The cryosurgical probe may be a multi-use cryosurgical probe. Multi-use cryosurgical probes may be coated with an inert coating selected to improve structural integrity of the cryosurgical probe against increased pressures. For example, multi-use cryosurgical probes may be coated in an inert gold coating. The cryosurgery probe may be or include any part as described in U.S. Pat. Nos. 5,254,116; 5,334,181; 5,800,487; 5,800,488; 5,910,104; 6,475,212; 6,142,991; 6,179,831; 6,139,544; 5,513,742; 6,471,694; and 5,978,697, each of which is incorporated herein by reference in its entirety for all purposes. The cryosurgical treatment may generally be sufficient to produce tissue ablation by freezing. Cryosurgical treatment may include bringing the target tissue to a temperature below the freezing temperature of biological tissues, typically −0.56° C. and lower. The effect of freezing the target tissue (whether preserving the biological matter or destroying it) may be controlled by selecting cooling rate during freezing and temperature.FIG.2illustrates the spatial temperature distribution during freezing of tissue10, as a function of time after the onset of freezing. The cryosurgical probe surface220is at the origin. The temperature distribution in the ice ball255ranges from the temperature of the cryosurgical probe on the outer surface of the probe255a(typically the coolest temperature of the treatment area), to the change of phase temperature at the outer margin of the frozen lesion in contact with the unfrozen tissue255b(typically the warmest temperature of the treatment area). In certain embodiments, cryosurgical treatment may be performed with intraoperative imaging, to monitor the extent of the frozen lesion in real time. The real time intraoperative imaging may be performed, for example, with a camera or sonogram. FIG.2shows a schematic of the ice ball around a typical cryosurgery probe. Cryosurgery probe part220may experience a range of temperatures from about 0° C. to −40° C. The frozen tissue, sometimes referred to as the “ice ball”255, may experience a range of temperatures from −40° C. to the phase transition temperature. Thus, a substantial portion of the frozen lesion may generally be between the 0° C. and −40° C. Therefore, while intraoperative medical imaging can generate a precise image of the outer margin of the frozen lesion, the extent of tissue ablation in that frozen region is typically unknown. Certain cells may survive temperatures up to about −20° C. By combining ablation methods, cell and tissue ablation may be improved. Other ablation methods may include, for example, electrolysis, electroporation (non-thermal irreversible electroporation and electrolytic electroporation), electrochemotherapy, radiofrequency, microwave, laser, and Joule heating. In particular, the cryosurgery instrument disclosed herein may combine cryogenic ablation with a non-thermal ablation method, such as electrolysis, electroporation (non-thermal irreversible electroporation and electrolytic electroporation), and electrochemotherapy, which is capable of generating products of electrolysis. The cryosurgical instrument may comprise at least one electrode for conducting a current through a solution. The solution may be native to the target tissue and/or may be introduced to the target tissue. In some embodiments, the at least one electrode may be a treatment pad for surface treatments. In some embodiments, the at least one electrode may include needle electrodes and/or a catheter for use within cavities and/or tissues. In some embodiments, the electrode may be thermally conductive. The electrode may be formed of an electrically conductive material, for example, graphite, copper, silver, titanium, brass or an electrically conductive polymer such as a thermoplastic resin polymer. One exemplary thermoplastic resin polymer is used in CONDUCTOMER®. The electrode may be formed of carbon, titanium, or titanium coated with an oxide. Systems and methods may comprise administering a solution for the electrolytic treatment. The solution may be an aqueous matrix administered in contact with the electrodes, proximate the target tissue. The aqueous matrix may be a biocompatible gel and/or a biocompatible solution, for example, a saline solution. The electrode may be configured to generate products of electrolysis at the target tissue. Products of electrolysis may be generated by electrolysis. Electrolysis generally involves running an electrical current between two electrodes (a cathode and an anode) through an aqueous medium. At the cathode, positive ions are drawn to the electrode, which delivers electrons. At the anode, electrons are accepted. A potential drop associated with activation energy typically occurs across a boundary layer around the electrodes. Biological tissue is an aqueous medium which may be treated with electrolysis. The electrical current may be sufficient to produce an electrochemical reaction at the electrodes in which electrons are transferred or received from the ions in the aqueous medium. The dose of electrical current may be sufficient to change the composition of the medium at the electrode boundary. In certain embodiments, the dose of electrical current may be sufficient to affect, through diffusion and electro-osmosis, the composition of the medium throughout a pre-selected volume of the medium. Products of electrolysis may be generated to perform electrolytic ablation. In biological tissue, the products of electrolysis can be toxic to living cells. The extent of cell death generally depends on the composition of the electrodes and the composition of the solution. There are various parameters that may be used to control the products and outcome of the electrolytic process. The parameters include, for example, dosage, current, charge (i.e. period of time of delivery of current), pH, the type of electrode and catalysts for enhancing or reducing the products of electrolysis. In particular embodiments, current per surface area of electrodes per unit time may be selected to control the extent of ablation. In some embodiments, voltage may be selected to control the extent of ablation. The electrodes may be capable of applying a voltage from 0.5 V to 500 V. However, the activation potential is dependent on electrode material and composition. Time of the reaction may be selected to be on the order of seconds to hours. In general, the products of electrolysis may be generated substantially continuously or in pulses. The electrodes may be capable of applying a current between about 0.0001 mA/cm2electrode surface to 1000 mA/cm2electrode surface. The specific voltage, timing, and current may be selected based on the material of the electrode, the composition of the target tissue, and the desired or target amount of tissue/cell ablation. Products of electrolysis may be generated by electroporation, for example, reversible and irreversible electroporation. Electroporation is the permeabilization of the cell membrane with electric fields delivered across the cell. Electroporation may be reversible. In reversible electroporation, generally the cell membrane recovers to the original permeability a certain time after the delivery of the pulses. Electroporation may be irreversible. In irreversible electroporation, generally the cell succumbs to the effects of the electric pulses. Both reversible and irreversible electroporation electric pulses may be designed to produce limited thermal damage. Thus, electroporation is typically considered a non-thermal method of ablation. Any tissue ablation technique, for example, reversible electroporation, may be used for tissue ablation in combination with the administration of cytotoxic chemicals, such as bleomycin or cisplatin (cisplatinum). The cytotoxic chemicals may be administered, for example, injected, into or near the target tissue prior to the delivery of the electroporation electric pulses. Irreversible electroporation may be used for non-thermal tissue ablation. Irreversible electroporation tissue ablation may be done by applying electric fields between two electrodes bracing the targeted tissue. Tissue ablation by irreversible electroporation may be performed by the methods described in U.S. Pat. No. 8,048,067, filed Oct. 18, 2006, titled “Tissue ablation with irreversible electroporation,” incorporated by reference herein in its entirety for all purposes. During electroporation, the electric field generated may also produce products of electrolysis. When purposefully generated in a controlled way, electrolysis can be used with electroporation in both the reversible and irreversible mode for tissue ablation. Thus, the methods disclosed herein may comprise generating products of electrolysis with electroporation. Electrolytic electroporation may include applying an electric field to permeabilize the cell membrane at a voltage and charge sufficient to generate products of electrolysis which contribute to the cell ablation. Electrolytic electroporation may be performed by the methods described in U.S. Patent Application Publication No. 2016/0296,269, filed May 12, 2016, titled “Methods, systems, and apparatus for tissue ablation using electrolysis and permeabilization,” incorporated herein by reference in its entirety for all purposes. The cryosurgical instrument may be capable of performing cryoelectrolysis. Cryoelectrolysis may refer to combinations of treatment which produce products of electrolysis (purposefully or inadvertently) with cryosurgery/cooling. Such treatments may include cryosurgery-electrolysis, cryoelectroporation, cryoelectrolytic-electroporation, cold electrolysis, cold electroporation and coldelectrolytic electroporation. As previously described, certain cells can survive cryosurgery in high subzero centigrade frozen tissue, from about −40° C. to the freezing interface. Non-thermal methods of tissue ablation, such as electroporation and electrolysis, may be combined with cryosurgery to ablate cells surviving cryosurgery, for example, without the injection of drugs into the treated tissue. Additionally, temperature may be used to modulate and control electric fields in biological tissues and can therefore be used to improve and control electrolytic treatments. Products of electrolysis may be delivered, before, during, and/or after the cryogenic treatment. The methods disclosed herein may be used to provide combined cryosurgical treatment and electrolysis, for example, with a cryosurgical instrument as described herein. The methods may generally comprise bringing the cryosurgical instrument into contact with a target tissue and delivering a cryosurgical treatment to the target tissue. The cryosurgical treatment may include cooling the target tissue to a temperature between about 0° C. and −40° C. For instance, the cryosurgical treatment may be provided by cooling the cryosurgical probe to a temperature between about 0° C. and −40° C., for example, about −40° C., about −30° C., about −20° C., about −10° C., about −5° C., or about 0° C. The cryosurgical probe may cool the contacted target tissue to the selected temperature range. The target temperature may be selected to cause a maximum amount of ablation by cryogenic freezing of the cells, or the target temperature may be selected to be below a threshold of cell death. The methods may additionally comprise generating products of electrolysis at the target tissue. The products of electrolysis may be generated by an electrical current of between about 0.0001 mA/cm2electrode surface to 1000 mA/cm2electrode surface, for example, between about 0.01 mA/cm2electrode surface to 1000 mA/cm2electrode surface, about 1 mA/cm2electrode surface to 500 mA/cm2electrode surface, or about 10 mA/cm2electrode surface to 200 mA/cm2electrode surface. The products of electrolysis may be generated by applying a voltage between about 0.5V and 500V, for example, between about 5V and 200V, or between about 5V and 50V. The applied current and voltage may be selected based on factors such as electrode material and composition of the target tissue. In general, the applied current and voltage may be selected to generate a pre-determined amount of products of electrolysis. Specifically, the applied current and voltage may be selected to effectively ablate the target tissue when applied in combination with the cryosurgery. The cryoelectrolysis may comprise providing the cryosurgical treatment and products of electrolysis such that each substantially simultaneously treats the target tissue. In some embodiments, a procedure that generates products of electrolysis may be followed by cryosurgery treatment. Electrolysis may deliver electrolysis products to the target tissue. Cells at the target tissue may have increased susceptibility to cell death due to the combined delivery of the electrolysis products and cryosurgery treatment. In some embodiments, electrolysis may be repeated after cryosurgical treatment. In some embodiments, electrolysis and cryosurgery may be performed at some time simultaneously. In some embodiments, electrolysis and cryosurgery treatment may be repeated in an alternating fashion for a desired period of time. Electrolysis and cryosurgery may be performed for the same or different time durations, magnitudes, and/or other parameters. In some embodiments, electrolysis and cryosurgery may be separated by a period of time where no treatment is applied to the target tissue. In some embodiments, cryosurgery treatment may be performed and may be followed by electrolysis. Cells at the target tissue may have increased permeability in response to the cryosurgery. In some embodiments, cryosurgery may be repeated after electrolysis. In some embodiments, cryosurgery and electrolysis may be repeated in an alternating fashion for a desired period of time. Cryosurgery and electrolysis may be performed for the same or different time durations, magnitudes, and/or other parameters. In some embodiments, cryosurgery and electrolysis may be separated by a period of time where no treatment is applied to the target tissue. In some embodiments, electrolysis and cryosurgery treatment may be performed at the same time or partially at the same time. For example, a current to generate electrolysis products may be applied during a same period of time as cryogenic temperatures are applied to the target tissue. In some embodiments, electrolysis and cryosurgery may both be performed together for a continuous period of time or intermittently. In some embodiments, one treatment may be performed continuously while the other treatment is performed intermittently. The magnitude and duration of each treatment may be modulated independently of the other treatment. For example, electrolysis may be performed for several seconds each minute, while cryosurgery treatment may be performed continuously for several minutes. The electrolysis may be discontinued while the cryosurgery treatment is continued. Such treatment combinations are exemplary. Other treatment protocols are within the scope of the disclosure. The time, duration, and order of the treatment may be selected based at least in part on the desired effect on the target tissue, the size of the target tissue, and/or local physiological conditions of the target tissue. Each of the cryosurgical treatment and the electrolysis may be independently controlled. For example, dosage, timing, and magnitude of the cryosurgical treatment and the electrolysis may be independently controlled. The method may comprise providing one or both treatments continuously, intermittently, or periodically. The method may comprise providing one or both treatments at a substantially constant magnitude or by varying magnitude, for example, increasing or decreasing the applied treatment over time. The method may comprise providing one or both treatments at a substantially constant dosage or by varying dosage, for example, increasing or decreasing the dosage in subsequent treatments. The method may comprise administering an initial dosage of the cryosurgical treatment and/or the electrolysis. The method may comprise administering one or more bolus dosages of the cryosurgical treatment and/or the electrolysis. The method may comprise monitoring the target tissue to determine the course of treatment. In other embodiments, the course of treatment may be pre-selected. For example, the target tissue may be pre-cooled or cooled during the delivery of current to avoid carbonization, which may also avoid loss of conductivity. The electric charge may be delivered in pulses (for example, as pulsed electric fields (PEF)). In some embodiments, the cryosurgical probe may simultaneously deliver pulsed electric fields and cooling temperatures. In such embodiments, the cryosurgical probe is electrically active and operates with the electrode. While not wishing to be bound by theory, it is believed that changes in electrical properties due to temperature produced by the pulsed protocol may magnify and confine electric fields in the cooled regions, while almost eliminating electric fields in surrounding regions. Simultaneous pulse protocols may be used to increase precision in the electrolytic procedure and reduce muscle contractions and damage to adjacent tissues. Additionally, electric pulses may induce blood flow stasis, which helps in reducing the heat load during cryosurgery. In some embodiments, the cryosurgical probe may be substantially electrically inactive, and only apply cooling boundary conditions. In such embodiments, the cryosurgical instrument may comprise an electrode pair operating to produce the electrolytic effect. The temperature induced changes in the electrical properties of tissue may reduce the electric fields in the cooled regions. Cryoelectrolytic treatment may be used to protect sensitive tissues from the effect of the electric field. During cryoelectrolysis, the dosage of cryogenic treatment and electrochemical current may be selected to treat an overlapping pre-selected volume of tissue. The pre-selected volume of tissue may be the target tissue. Thus, the target tissue includes a volume of tissue pre-selected for substantially simultaneous treatment by the cryosurgical probe and the products of electrolysis. The cryosurgical probe and the at least one electrode may be positioned and arranged to treat the target tissue. In some embodiments, the electrode may be fastened to the cryosurgical probe. In some embodiments, the electrode may be separate from the cryosurgical probe. In use, the cryosurgical probe may be placed proximately to the at least one electrode. In use, the cryosurgical probe may be placed at a pre-selected distance from the at least one electrode. The positioning may be selected based on the location and size of the target tissue. The cryosurgical instrument may comprise an array of cryosurgical probes and electrodes. The at least one cryosurgical probe and the at least one electrode may be localized on the cryosurgical instrument in a variety of ways. In some embodiments, at least one electrode may be coupled and/or fastened to the cryosurgical probe. For example, at least one electrode may be coupled and/or fastened to a portion of the exterior surface of the cryosurgical probe. In some embodiments, at least one electrode may be dimensioned to conform to at least a portion of the exterior surface of the cryosurgical probe. An electrode coupled to the cryosurgical probe may be movable along the exterior surface of the cryosurgical probe. For example, the positioning of the electrode on at least a portion of the exterior surface of the cryosurgical probe may be variable. In certain embodiments, the electrode may be expandable or contractable, such that the electrode may occupy a greater or smaller surface area on the surface of the cryosurgical probe. The localization of the cryosurgical probe and the at least one electrode on the cryosurgical instrument may be fixed or variable. In some embodiments, coupled and/or fastened components may be removable, for example, reversibly removable. In some embodiments at least one electrode may be distinct from the cryosurgical probe. The distance between the cryosurgical probe and the distinct electrode may be fixed or variable. For example, the cryosurgical probe and/or the electrode may be rigidly positioned on the cryosurgical instrument or flexibly positioned. An electrode may be placed near the intended margin of the frozen lesion while the cryosurgery probe is placed at a site removed from the intended margin, which may promote cell death at or near the margin without reaching low subzero temperatures in the same region. To provide products of electrolysis, the cryosurgical device may generally comprise an anode and a cathode. The at least one electrode may include at least one electrode which is electrically wired as an anode and at least one electrode which is electrically wired as a cathode. In some embodiments, the electrode may generate products of electrolysis by operating in conjunction with the cryosurgical probe. Thus, the cryosurgical probe may be electrically wired as the second electrode. In certain embodiments, the cryosurgical probe may be electrically wired as an anode. In certain embodiments, the cryosurgical probe may be electrically wired as a cathode. However, the products of electrolysis effective to perform tissue ablation can cause damage to the cryosurgery probe. Corrosion to the material of the cryosurgical probe by products of electrolysis can be detrimental to the subject, in some instances, life threatening. The cryosurgical instrument disclosed herein may comprise a protective member coupled to at least a portion of an exterior surface of the cryosurgical probe. In embodiments which include more than one cryosurgical probe, at least one cryosurgical probe may comprise a protective member. The protective member may be effective to substantially isolate the cryosurgical probe from the products of electrolysis. In some embodiments, the protective member may be effective to completely isolate the cryosurgical probe from the products of electrolysis. The protective member may be thermally conductive. For instance, the protective member may substantially isolate the cryosurgical probe from products of electrolysis, while maintaining thermal treatment of the target tissue. The protective member may not substantially interfere with the heat transfer between the target tissue and the cryosurgical probe. Furthermore, the protective member may not substantially interfere with the electrolytic treatment at the target tissue. The protective member may be dimensioned to effectively substantially isolate the cryosurgical probe from the products of electrolysis. For example, the protective member may have a thickness effective to substantially isolate the cryosurgical probe from the products of electrolysis when conformed to the cryosurgical probe. The protective member may have a thickness of between about 0.001 mm to about 5.0 mm, for example, between about 0.01 mm to about 3.0 mm or between about 0.1 mm to about 2.0 mm, when conformed to the cryosurgical probe, i.e. from an interior surface of the protective member facing and/or contacting the cryosurgical probe to an exterior surface of the protective member facing and/or contacting the target tissue. The effective dimensions to substantially isolate the cryosurgical probe from the products of electrolysis may be dependent on the material of the protective member and the amount of products of electrolysis (which may be dependent on the composition of the target tissue and the electrolysis dosage). The protective member may be formed of a material effective to substantially isolate the cryosurgical probe from the products of electrolysis. For example, the material of the protective member may be effective to substantially isolate the cryosurgical probe from the products of electrolysis when provided at the effective dimensions (described above). The effective material to substantially isolate the cryosurgical probe from the products of electrolysis may be dependent on the dimensions of the protective member and the amount of products of electrolysis (which may be dependent on the composition of the target tissue and the electrolysis dosage). The protective member may be in the form of a metallic coating on the cryosurgical probe. The metallic coating may be fixed or removable. The metallic coating may provide galvanic protection to the cryosurgical probe material when exposed to products of electrolysis. In some embodiments, the material of the protective member may be more anodic than the material of the cryosurgical probe. Table 1 includes a list of metallic materials, from most active (more anodic) to least active (less anodic). The protective member may be formed of a material higher up in Table 1 from the material of the cryosurgical probe. Materials on the same line of the table are substantially equally anodic. TABLE 1Cryosurgical Probe and Protective Member Materials, Most Anodic to Least AnodicMagnesium——————alloysZinc——————Beryllium——————AluminumAluminumAluminumAluminumAluminum——11003003300450526053Galvanized——————steelCadmium——————AluminumAluminumAluminum————201720242117Mild steelWrought—————1018ironCast ironLow alloy—————highstrengthsteelChrome iron——————(active)Stainless——————steel 430series(active)StainlessStainlessStainlessStainlessStainlessStainlessStainlesssteel 302steel 303steel 304steel 321steel 347steel 410steel 416(active)(active)(active)(active)(active)(active)(active)Nickel——————(resist)StainlessStainless—————steel 316steel 317(active)(active)Carpenter 20——————CB-3stainless(active)Aluminum——————bronze (CA687)Hastelloy CInconelTitanium————(active)625(active)(active)Lead-tin——————soldersLead——————Tin——————Inconel 600——————(active)Nickel——————(active)Brass (naval)BrassBrassBrass———(yellow)(red)(admiralty)Copper (CA——————102)ManganeseManganese—————bronzetinSilicon——————bronzeNickel silver——————Copper-——————nickel alloyStainless——————steel 430NickelAluminumBronze————(passive)Monel 400K 50—————Silver solder——————Nickel——————(passive)Chrome iron——————(passive)StainlessStainlessStainlessStainlessStainless——steel 302steel 303steel 304steel 421steel 347(passive)(passive)(passive)(passive)(passive)StainlessStainless—————steel 316steel 317(passive)(passive)Carpenter 20Incoloy—————CB-3825stainless(passive)Nickel——————Molybdenumchromiumiron alloy(passive)Silver——————TitaniumTitanium—————alloysGraphite——————Zirconium——————Gold——————Platinum—————— The protective member may be a sacrificial member. In use, the products of electrolysis may cause corrosion of the more anodic sacrificial material. However, the extent to which a sacrificial protective coating can continue to protect the cryogenic probe is directly related to the thickness of the protective member, because the protective member may wear out with use. Thus, in some embodiments, the protective member may have a thickness effective to withstand a cryoelectrolysis treatment. The protective member may be a single-use device. The protective member may be a non-sacrificial coating. For example, the protective member may be formed of platinum or a polymer (conductive or non-conductive polymer). The protective member may be non-electrically conductive. For example, the protective member may be formed of a non-electrically conductive plastic, such as teflon. In some embodiments, the protective member may be electrically insulating or may comprise an electrically insulating layer. ANSI standards, for example, ANSI C33.60 may be used for the electrical insulation material. The material of the protective member may be thin, so as not to interfere with heat transfer from the cryosurgical probe. The protective member may be substantially free of impurities and formed with a robust material. It is noted that if the cryogenic probe becomes exposed through an impurity in the protective member, the cryogenic probe material may corrode when contacted with the products of electrolysis. In some embodiments, the protective member may be movable along the exterior surface of the cryosurgical probe. For example, the positioning of the protective member on at least a portion of the exterior surface of the cryosurgical probe may be variable. In certain embodiments, the protective member may be expandable or contractable, such that the protective member may occupy a greater or smaller surface area on the surface of the cryosurgical probe. The protective member may be removable, for example, reversibly removable, from the cryosurgical instrument. Thus, a cryosurgical probe protective device is disclosed herein. The protective device may be dimensioned to conform to at least a portion of an exterior surface of the cryosurgical probe. The protective device may be malleable or substantially rigid. The protective device may be provided in a sealed container. For example, the protective device may be provided in sterile packaging. The protective device may be individually wrapped. The protective device may be a single-use device. The protective device may be a multi-use device. In some embodiments, the protective member may be formed as a single piece with the electrode. Thus, the protective device may comprise an electrode portion adjacent to the protective portion. When assembled, the electrode may be coupled to a portion of the exterior surface of the cryosurgical probe adjacent to the protective member. A kit comprising the protective device (as previously described) and instructions for use is also disclosed. The instructions may instruct a user to apply the protective device to the cryosurgical probe. The instructions may instruct the user to fasten the protective device to the cryosurgical probe. In some embodiments, the instructions may provide one or more parameter for the cryoelectrolytic treatment, for example, a minimum temperature or maximum electrical charge which may be applied to the protective device without causing substantial damage to the protective device. The cryosurgical instrument may further comprise a vacuum layer between the exterior surface of the cryosurgical probe and the protective member. In some embodiments, the vacuum layer may be movable along the exterior surface of the cryosurgical probe. For example, the vacuum layer may be movable along the exterior surface of the cryosurgical probe independently from any mobility of the protective member. The vacuum layer may have a thickness of between about 0.01 mm to about 5.0 mm, for example, between about 0.1 mm to about 2.0 mm. In some embodiments, the cryosurgical instrument may comprise a heat transfer fluid between the cryosurgical probe and the protective member. The cryosurgical instrument may be part of a system for performing cryoelectrolysis. In addition to the cryosurgical instrument, the system may include a cryogenic power supply electrically connected to the cryosurgical probe, an electrolysis power supply electrically connected to the at least one electrode, and a controller. The system may additionally include one or more sensors configured to measure a parameter of the target tissue and provide feedback information to the controller. Methods of producing a cryosurgical instrument are also disclosed. The methods may comprise selecting a cryosurgical probe and selecting an electrode. In certain embodiments, the methods may comprise selecting an arrangement for the cryosurgical probe and electrode, and, optionally, coupling and/or fastening the electrode to the cryosurgical probe. The methods may comprise coupling and/or fastening a protective member or device to the cryosurgical probe. For example, the methods may comprise coupling and/or fastening a protective member or device to at least a portion of an exterior surface of the cryosurgical probe. In certain embodiments, the methods may comprise positioning a vacuum layer between the external surface of the cryosurgical probe and the protective member. The methods of producing a cryosurgical instrument may comprise selecting materials for one or more of the cryosurgical probe, the electrode, and the protective member. Properties which may be considered when selecting the materials include, for example, electrical conductivity, thermal conductivity, corrosion resistance, hardness, and form. As disclosed herein, “electrical conductivity” refers to a material's ability to carry or conduct an electric current. Electrical conductivity may be reported as a percent of the copper standard, 100% IACS (International Annealed Copper Standard). As an exemplary embodiment, silver has an IACS of 105%. As disclosed herein, “thermal conductivity” refers to a material's ability to carry or conduct heat. As an exemplary embodiment, gold is a material with high thermal conductivity. As disclosed herein, “corrosion resistance” is a material's ability to resist chemical decay. A material that has little corrosion resistance will degrade rapidly in corrosive environments, resulting in a shorter lifespan. As an exemplary embodiment, platinum group metals are known for high resistance to corrosion. Polymer materials such as teflon are generally resistant to corrosion. As disclosed herein, “hardness and elasticity” is the measure of how resistant the material is to various kinds of permanent deformations resulting from an applied force. Hardness is generally dependent on a material's ductility, elasticity, plasticity, tensile strength, and toughness. In particular, hardness may be considered in the design of the protective member, as the insertion of a cryosurgical instrument in hard tissue is associated with substantial stresses and deformations. As disclosed herein, “form” may generally refer to the shape an electrical material must fit in order to carry out its operation. Exemplary shapes include contact tips, pins, sockets, stampings, sheets, wires, and wheels. The methods may comprise selecting a material for the protective member which facilitates the isolation of the cryosurgical probe from a potential electrolytic environment. The protective member may be formed of a material which has low electrical conductivity and high corrosion resistance. The methods may comprise selecting a material for the protective member which does not substantially interfere with the removal of heat from the target tissue by the cryosurgical probe. The protective member may be formed of a material which has good thermal conductivity near the cooling part of the cryosurgical probe. Good thermal conductivity may be achievable by selecting a material with good thermal conductivity or selecting a thin form of a material with lower thermal conductivity. The methods may comprise selecting a material for the protective member which does not substantially interfere with the electrolytic process in the target tissue. The protective member may be formed of a material which has a high electrical conductivity and a high corrosion resistance. The methods may comprise selecting a material for the protective member which is substantially biocompatible. For sufficient biocompatibility, the material may be selected such that the products of electrolysis have a safe reaction with the material. Exemplary materials include carbon. In other embodiments, the material may be selected such that the products of electrolysis have a reaction with the material which contributes to tissue ablation. Exemplary materials include silver and copper. The methods may comprise selecting a material which has a sufficient hardness and elasticity to be compatible with the function of a cryosurgical probe. The methods may comprise selecting a material for the protective member to be thermally conductive. The methods may comprise selecting a material for the protective member to be more anodic than a material of the cryosurgical probe. The methods may comprise selecting a material for the protective member and/or electrode from stainless steel, lead, gold, silver, copper, graphite, carbon, titanium, brass, bronze, platinum, palladium, mixed metal oxides, nickel, polymers (for example, nylon or polyolefin), composites thereof (for example, composites of conductive materials and insulative materials such as pyralux distributed by DuPont, Wilmington, DE, which is a composite of copper and polymer), and alloys thereof (for example, copper alloys with graphite, tellurium, and tungsten). In an exemplary embodiment, the methods may comprise selecting copper as a material for the electrode and/or protective member. Copper ions are toxic to cells. The use of a protective member comprising copper may be desirable to enhance cell ablation. Alternatively, the use of a protective member comprising copper may not be desirable because of toxicity to tissue. In an exemplary embodiment, the methods may comprise selecting graphite and/or carbon as a material for the electrode and/or protective member. Carbon is very inter-corrosion resistant, and electrochemically noble compared to many metals, which makes carbon a useful material for electrochemical and electrowinning electrodes. One drawback of carbon is the hardness and lack of elasticity. In an exemplary embodiment, the methods may comprise selecting titanium or titanium oxide as a material for the electrode and/or protective member. Titanium has excellent corrosion properties. A thin layer of titanium or titanium oxide may be provided either through machining or electrodeposition. In an exemplary embodiment, the methods may comprise selecting silver as a material for the electrode and/or protective member. Silver has high conductivity, softness (low hardness), and high resistance to oxidation. Silver may be strengthened with copper and other alloy additions, but at the sacrifice of conductivity. Silver may be selected in the form of Ag/AgCl. Silver ions are toxic to cells. The use of a protective member comprising silver may be desirable to enhance cell ablation. Alternatively, the use of a protective member comprising silver may not be desirable because of toxicity to tissue. In an exemplary embodiment, the methods may comprise selecting platinum and/or palladium as a material for the electrode and/or protective member. Platinum and palladium have very high erosion and corrosion resistance with low contact resistance. Platinum may be used as an alloy with iridium, ruthenium, and/or tungsten. Palladium may be used as an alloy with copper and/or ruthenium. The electrode and/or protective member material may comprise mixed metal oxides (MMO), for example, as a coating. Electrodes may typically have an oxide coating over an inert metal or carbon core. The oxides may include precious metal (for example, ruthenium, iridium, and platinum) oxides for catalyzing an electrolysis reaction. Dimensionally stable anodes may include a titanium base, coated with a very thin layer of mixed metal oxides. Titanium oxides may be used for inertness, electrode corrosion protection, and lower cost. Ruthenium and iridium oxides can be deposited on titanium, providing a catalytic effect to enhance the electrolytic reaction and promote the formation of hypochlorous acid, a chemical species that is effective at ablating cells and also used by the T-cells for cell ablation. FIG.1is a schematic illustration of a system100including a cryosurgical instrument125. The system100may be capable of performing both cryosurgery and an electrolysis product generating process. As shown inFIG.1, the cryosurgical instrument125may be used on the surface of a target tissue10, within the target tissue10, proximate the target tissue10, and/or in a cavity formed by the target tissue10. Exemplary system100includes controller105. The controller105is operatively connected to the electrolysis power supply110and the cryogenic power supply115, each of which is electrically connected to the cryosurgical instrument125. The electrolysis power supply110and the cryogenic power supply115are shown as distinct devices inFIG.1. However, the electrolysis power supply110and the cryogenic power supply115may be the same device. When in use, power supplies110,115may be placed proximate to the treatment site or remotely from the treatment site. The system100may include a source of an aqueous solution (not shown) for administration to the target tissue. The aqueous solution may be effective to enhance the electrolytic treatment. The controller105may be configured to control one or more parameter of the treatment. For example, the controller105may be configured to control at least one of dosage, timing, and magnitude of the cryosurgical treatment and the electrolysis. In general, the controller105may be configured to control the parameters for the cryosurgical treatment independently from the parameters of the electrolysis. The controller105may be configured to control the at least one parameter by instructing the power supplies110,115. For example, the controller105may be programmable to provide an generate an electric signal and to generate a cryogenic signal. The signals may be delivered to the power supplies110,115, respectively. The controller105may allow a user to customize treatment. In some embodiments, a feedback system may be included in a communication path between the controller105and the cryosurgical instrument125. System100may include one or more sensors150positioned to measure a property at the target tissue10. The sensor150may be positioned on the cryosurgical instrument125or remotely from the cryosurgical instrument125. The parameter may be, for example, temperature, pH, or electric field strength. Thus, the sensor150may be, for example, a temperature sensor, an electric current sensor, an electric potential sensor, a pH sensor. Systems and methods disclosed herein may comprise measuring pH at the target tissue, for example, with sensor150, during treatment, prior to treatment, and/or after treatment. The method may comprise providing or altering electrolysis responsive to the measured pH value. The method may comprise providing a pH adjusting agent to alter or control pH at the target tissue. The controller105may be configured to generate or modify the electric signal responsive to the pH measurement obtained by the sensor150. In exemplary embodiments, the pH sensor150may sense pH near the electrode and transmit the pH value to the controller105. The controller105may be programmed to adjust an electric signal provided to the electrode based on the pH value near the electrode. A source of a pH adjusting agent (not shown) may be provided to store and deliver pH adjusting agent, for example, buffers or other solutions, to the target tissue. In another exemplary embodiment, the pH sensor150may be positioned to measure pH at the outer edge of the target tissue. The pH sensor150may detect when the pH level at the target tissue edge has reached a pre-selected level, which may help ensure tissue ablation at the edge and throughout the target site. Detection of a desired pH level may be a prompt for the controller105to terminate electrolysis. In another exemplary embodiment, the pH sensor150may be positioned at a selected target site and may detect pH level at the site as pH is reaching or has reached an undesirable value. Detection of a given pH value may be a prompt for the controller105to terminate electrolysis, which may help avoid tissue damage. The controller105may be programmed to control pH near an anode to be between 6.5 and 2.5, for example, between 4.5 and 2.5. The controller105may be programmed to control pH near a cathode to be between 7.5 and 11, for example, between 8 and 10. The controller105may control pH by adjusting electric signal and/or instructing the source of pH adjusting agent to deliver a pre-determined amount of the pH adjusting agent. Thus, the controller105may be operatively connected to the source of pH adjusting agent. Systems and methods disclosed herein may comprise measuring electric field strength (for example, electric current and/or electric potential) at the target tissue, for example, with sensor150, during treatment, prior to treatment, and/or after treatment. The method may comprise providing or altering electrolysis responsive to the measured electric field strength value. The controller105may be configured to generate or modify the electric signal responsive to the electric field strength measurement obtained by the sensor150. Systems and methods disclosed herein may comprise measuring temperature at the target tissue, for example, with sensor150, during treatment, prior to treatment, and/or after treatment. The method may comprise providing or altering the cryosurgical treatment responsive to the measured temperature value. The controller105may be configured to generate or modify the cryogenic signal responsive to the temperature measurement obtained by the sensor150. The controller105may be a separate component coupled to the power sources110,115, as shown inFIG.1, or the controller105may be integrated into one or both power sources110,115, or packaged together with one or both power sources110,115. In some embodiments, the controller105may include a programmable chip coupled to the power sources110,115. In some embodiments, the controller105may be implemented using a computing device (not shown) and may be remotely coupled to the devices110,115. The computing device may be, for example, a desktop computer, laptop computer, server, cloud-based server, handheld computing device, tablet computer, and/or a smart phone. In some examples, the computing device may be integrated with and/or shared with a separate piece of medical equipment. The controller105may be coupled by a wire to the devices110,115or may communicate with the devices110,115wirelessly. In some embodiments, two separate controllers105may be used in the system100. Each controller105may be coupled separately to one of the power sources110,115. Multiple controllers105may be coupled separately to one or more sensors150. The controller105may include a memory storage device or be coupled to a server or cloud computing system with memory storage. The controller105may, for example, include such a program, or include one or more processing devices (e.g. processors) coupled to the memory encoded with executable instructions for electrolysis treatment or cryosurgical treatment. The controller105may include an input device, for example, a keyboard, mouse, trackpad, or touch pad, and an output device, for example, a screen or speaker. The controller105may be programmed to operate with a mobile application and/or transmit notifications to a handheld computing device. The systems described herein may additionally comprise one or more pumps, valves, and lines to carry out the functions described above. The system may be electrically connected to a power source and/or battery. The system may be stationary or portable. FIGS.3-11are schematic drawings of different cryosurgical instruments.FIG.3is a schematic drawing of a cryosurgical instrument325comprising a cryosurgical probe320, protective member340covering a portion of the exterior surface of the cryosurgical probe320, and electrodes330,335. Electrode330may be wired as the anode for electrolysis treatment. Electrode335may be wired as the cathode for electrolysis treatment. Protective member340may substantially isolate cryosurgical probe320from the products of electrolysis generated by electrodes330,335. In some embodiments, protective member340may be electrically insulating. FIG.4is a schematic drawing of an alternate cryosurgical instrument425. Cryosurgical probe420is covered with an integral protective member440and electrode430device. The protective member440and electrode430have different thermal and electrical properties. Protective member440is formed as a sleeve around the cryosurgical probe420that is made of electrically insulative materials. Protective member440can also have thermal insulative properties. Electrode430is formed of a material which is both electrically and thermally conductive. The electrical charge to the electrode430can be delivered either by connecting the electrode430directly to the power supply or connecting an electrically conductive cryosurgical probe420to the power supply. Either connection may result in an electrical charge on the outer surface of the electrode430, in contact with the target tissue. In such a configuration, the electrode430may be in good thermal and electrical contact with the cryosurgical probe420. Adequate thermal and electrical contact can be achieved by good mechanical contact between part430and420or the use of a thermal connective fluid or gel, such as THERM-A-GAP GEL (distributed by Parker Chomerics, Woburn, MA), CoolTherm® MG-122 (distributed by LORD Corp., Cary, NC), or solutions of graphite. FIG.5is a schematic drawing of another exemplary cryosurgical instrument525. Cryosurgical instrument525includes cryosurgical probe520. Protective member540is coupled to cryosurgical probe520. In the exemplary embodiment ofFIG.5, the entire cryosurgical probe520is covered by protective member540. Protective member540may be an electrically insulative material. Electrode530is coupled to protective member540, covering a portion of protective member540. In some embodiments, electrode530is movable along protective member540. FIG.6is a schematic drawing of another exemplary cryosurgical instrument625. Cryosurgical instrument625includes cryosurgical probe620. Protective member640is coupled to cryosurgical probe620. In the exemplary embodiment ofFIG.6, the entire cryosurgical probe620is covered by protective member640. Electrode630is fastened to the cryosurgical instrument626adjacent to the cryosurgical probe620. Electrode630may be a cylindrical electrically conductive material. Electrode630is fastened to the instrument by an extension of the protective member640. Electrode630is also covered with a portion of the protective member640. Protective member640may be electrically insulative, to target or direct delivery of the electrical charge at a desired location. Electrode630may be near the cryosurgical probe620or at a greater distance from the cryosurgical probe620. FIG.7is a schematic drawing of another exemplary cryosurgical instrument725. Cryosurgical instrument725includes cryosurgical probe720. Protective member740is coupled to cryosurgical probe720. In the exemplary embodiment ofFIG.7, the entire cryosurgical probe720is covered by protective member740. Electrode730is not fastened to the cryosurgical probe720. Instead, electrode730is separate from the cryosurgical probe720and protective member740arrangement. FIG.8Ais a schematic drawing of another exemplary cryosurgical instrument825. Cryosurgical instrument825includes cryosurgical probe820and electrode830. Protective member840is coupled to cryosurgical probe820on an exterior surface of the electrode830. Protective member840may be formed of a dielectric material, for example, parylene or teflon, for electrical insulation. Cryosurgical instrument825includes vacuum layer895which provides a gas insulation effect. Cryosurgical probe820includes channel870for circulation of the cooling fluid. Cryosurgical instrument825includes channel855for heat transfer fluid. FIG.8Bis a schematic drawing of an alternate configuration of exemplary cryosurgical instrument825as shown inFIG.8A. The embodiment of cryosurgical instrument825ofFIG.8Bis the same as cryosurgical instrument825ofFIG.8A, except the cryosurgical probe820has a blunt tip. FIG.9is a schematic drawing of another exemplary cryosurgical instrument925. Cryosurgical instrument925includes cryosurgical probe920and electrode930. Protective member940is coupled to cryosurgical probe920on an exterior surface of the vacuum layer995. Vacuum layer995is positioned within protective member940on an exterior surface of the electrode930. Protective member940is movable along cryosurgical instrument925to provide variable length heat insulation. The variable length heat insulation may be used to select a size of the ice balls. Cryosurgical probe920includes channel970for circulation of the cooling fluid. FIG.10is a schematic drawing of another exemplary cryosurgical instrument1025. Cryosurgical instrument1025includes cryosurgical probe1020and electrode1030. Protective member1040is coupled to cryosurgical probe1020on an exterior surface of the vacuum layer1095. Vacuum layer1095is positioned within protective member1040on an exterior surface of the electrode1030. Protective member1040is movable along cryosurgical instrument1025to provide variable length heat insulation. The larger tip of the cryosurgical probe1020may be used to produce larger ice balls than, for example, the embodiment ofFIG.9. Cryosurgical probe1020includes channel1070for circulation of the cooling fluid. FIG.11is a schematic drawing of another exemplary cryosurgical instrument1125. Cryosurgical instrument1125includes cryosurgical probe1120and electrode1130. Protective member1140is coupled to cryosurgical probe1120on an exterior surface of the electrode1130. Vacuum layer1195is positioned within vacuum sleeve1196on an interior surface of the electrode1130. Interior vacuum sleeve1196is movable along cryosurgical probe1120to provide variable length heat insulation. The variable length heat insulation may be used to select a size of the ice balls. Cryosurgical probe1120includes channel1170for circulation of the cooling fluid. FIG.12includes schematic drawings of cryosurgical instruments1200A and1200B in use treating tissue10. Cryosurgical instruments1200A-1200B are inserted in a target tissue cavity. The figure shows cross sections through the cavity in the target tissue10. Cryosurgical probe1220includes protective member1240at a distal end. Electrodes1230are arranged slightly differently in cryosurgical instruments1200A and1200B. In1200A, both the anode and cathode are on the cryosurgical probe1220. In1200B, only either the anode or cathode are on the cryosurgical probe1220. In use, cryosurgical probe1220may be wired as the opposite electrode. FIG.13is a schematic drawing of another exemplary cryosurgical instrument1325. Cryosurgical instrument1325includes cryosurgical probe1320. Protective member1340is coupled to cryosurgical probe1320. In the exemplary embodiment ofFIG.13, the entire cryosurgical probe1320is covered by protective member1340. Cryosurgical instrument1325includes a plurality of electrodes1330. Each of the electrodes1330can be independently wired as anodes or cathodes, as required for the delivery of the products of electrolysis. Methods of retrofitting a cryosurgical probe are also disclosed herein. The methods may include providing a cryosurgical probe. The protective device may be used to protect an existing cryosurgical probe or replace one or more parts of an existing cryosurgical probe, such as another coating. Thus, the methods may comprise coupling the cryosurgical probe with a protective device and/or fastening the protective device to a cryosurgical probe. The methods may comprise removing one or more exterior part of a cryosurgical probe prior to coupling and/or fastening a protective device onto the cryosurgical probe. FIG.14includes schematic drawings of cryosurgical instruments1400A and1400B in use treating tissue10. Cryosurgical instruments1400A and1400B include conduit1470for delivery of cooling fluid (cryogen) to front chamber1475which contacts the target tissue for cryosurgical treatment. The walls of conduit1470and front chamber1475are designed to withstand pressure that is associated with the flow of the cooling fluid. For example, the walls of the front chamber1475may be formed of a material which is both thermally conductive and has the ability to withstand high pressure. Conduit1480is the path of the return cooling fluid from front chamber1475. Chambers1485in cryosurgical probe1400A are configured to thermally isolate the tissue from the cooling effect of the cryosurgical probe1400A and deliver the cooling effect at a targeted location of the tissue. Chambers1485may be filled with air or vacuum. Exemplary cryosurgical instruments1400A and1400B may be retrofit with a protective device as disclosed herein. For instance, chambers1485of cryosurgical instrument1400A may be replaced with a protective device. Cryosurgical instrument1400B may be covered or partially covered with a protective device. The resulting retrofit cryosurgical probe may be used to provide cryoelectrolytic treatment, as previously described. FIG.15is a schematic drawing of another exemplary cryosurgical instrument1525. Cryosurgical instrument1525includes cryosurgical probe1520covered by protective member1540. Cryosurgical probe1520includes conduits1570and1580for the cooling fluid and front chamber1575for providing cryosurgical treatment upon contact with the target tissue. Chamber1585may thermally isolate the tissue from the effect of the cooling fluid. Chamber1585may be left open to air or it can be filled with an insulating material. Thermocouples1590may be placed in chamber1585at desirable locations when the chamber is left open to air. Thus, the cryosurgical probes as shown inFIG.14may be retrofit to include protective member1540. The function and advantages of these and other embodiments can be better understood from the following examples. These examples are intended to be illustrative in nature and are not considered to be limiting the scope of the invention. EXAMPLES Example 1: Animal Studies Showing the Effect of Electrolysis on the Materials of Cryosurgical Probes Cryosurgical probes are typically designed to withstand high pressure and to be biocompatible. Commercial cryosurgery probes were used in the experiments described below. An R2.4 renal 2.4 mm stainless steel cryoprobe (distributed by Endocare Inc., Austin, TX USA) was tested with a single port control console device regulating flow duration and monitoring feed-back temperatures. The probe was supplied by a pressurized Argon gas container through the control console, at a constant pressure of 3000 psi. The cooling of the stainless steel cryoprobe was accomplished through a Joule-Thomson internal valve. The cryosurgery probes also served as the electroporation/electrolysis electrodes. For electroporation, a 2510 Electroporation System power supply (distributed by Eppendorf, Hamburg, Germany) was used to generate power. For electrolysis, the metal body of the probe was connected to a DC power supply (distributed by Agilent, Santa Clara, CA USA). The experiments were performed in pigs treated in accordance with Good Laboratory Practice regulations, as set forth in 21 CFR § 58. Experiments were conducted in compliance with all ethical and legal rules imposed by national legislation and the European Union. The experiment protocol was approved by the Ethics Committee of Fundeni Clinical Institute, and by the Bucharest Sanitary-Each procedure started with anesthetization of the animal under general anesthesia per SOP #33156. Preanesthetic medication (2.0 mL Telazol 4.0 mg/kg IM and 1.8 mL Atropine 0.02 mg/kg IM) was administered to the animals. Anesthetic induction was done by Isoflurane with oxygen at 2%/2 L/minute via mask. Possible postoperative pain was ameliorated by Buprenorphine 0.01 mg/kg IM Pre-med at recovery and Carprofen 4 mg/kg at extubation/recovery. Antibiotics administered during surgery were Cefazolin 25 mg/kg IV every 2 hours. In addition, pancuronium (0.1 mg/kg, at a dose of 1 mg/ml) was administered through an IV prior to the procedure, to reduce muscle contractions during the application of the electrical pulses. Pancuronium (0.05 mg/ml at 1 mg/ml) was administered throughout the procedure as needed. The liver was exposed via a midline incision. Two cryosurgery probes were inserted normal to the liver outer surface, parallel to each other to a depth of 3 cm, separated by 3 cm, center to center. One of the probes served as the anode and the second as the cathode. The following protocol was applied. First, one single pulse was applied with the Eppendorf electroporation device set to 2500 V set to 1.5. The device delivered 2000 V in an exponential decay of 2.2 ms. The pulse was followed by the delivery of an electrolytic current of 70 mA for 10 minutes, which delivered a 42 Coulomb charge. The electrolytic current was followed by freezing with the cryosurgery device set at 2,800 psi Argon flow for ten minutes. The cryosurgical probe which served as the anode failed within five minutes after the onset of freezing. Evidence of release of gas from the cryosurgical probe tip was observed. The animal studies on the combination of cryosurgery and electrolysis were stopped after equipment failure. Thus, the combined treatments in an animal study caused failure and damage to the conventional cryosurgerical probe. Example 2: Agar Gel Studies Showing the Effect of Electrolysis on the Materials of Cryosurgical Probes Experiments as described in Example 1 were performed in agar gels. The first electrolysis was delivered in the form of 200 mA for 10 min at 10V. Electrolysis was followed by freezing with the cryosurgery device set at 2,800 psi Argon flow for 10 min. The trocar tip of the cryoprobe that served as the anode was detached and damaged. Around the anode there was a dark rim of metal particles, which was caused by the electrolytic decomposition of the cryosurgical probe. As in Example 1, the combined treatments in an agar gel caused failure and damage to the conventional cryosurgical probe. Example 3: Effect of Electrolysis on the Materials of Cryosurgical Probes Experiments as described in Examples 1 and 2 were performed on various cryosurgical probes. Photographs of the damaged probes (anode and cathode) are shown inFIG.16. Briefly, freezing was delivered first. After 10 minutes of freezing, the cooling was ceased and an electrolytic current of 100 mA at 40 V was delivered for 10 minutes. As seen in the photographs ofFIG.16, cryosurgery probes1661,1662,1663, and1664are damaged. These cryosurgery probes served as the anode. Cryosurgery probe1660, which served as the cathode, appears to have suffered from less damage. Example 4: Effect of Electrolysis on Aluminum Coated Cryosurgical Probes It is believed that an effective placement of the electrodes in cryoelectrolysis is correlated with the placement of the cryosurgery probe. The location may be selected to provide a superposition of the region affected by electrolysis on the region affected by freezing. Since conventional cryosurgery probes are made of electrically conductive materials, they may be used as the electrode. However, the findings in Examples 1-3 show that electrolysis can damage the material of the cryosurgery probe, and patient safety requires a different technology for enabling the combination electrolysis generating electrical currents in cryoelectrolysis, cryoelectroporation, and cryoelectrolytic-electroporation and freezing. One embodiment of a safe cryoelectric probe is shown inFIG.17.FIG.17shows the components and the assembly of a cryoelectric device1763, according to an embodiment described herein. The device shown inFIG.17may be assembled on a conventional cryosurgery probe, for example, an R2.4 cryosurgery probe as described above. A higher magnification detail of the shaft and tip of the probe is shown in1762. The cryoprobe base was insulated using a shrinking tube1761having an inner diameter of 2.5 m and a tube wall thickness 0.2 mm. A strip of 4 cm×3 cm of an aluminum sheet1760having a thickness of 0.5 mm was tightly wrapped around the cryosurgical probe. The active part of the cryosurgical probe, which was covered by the aluminum sheet, was 3 cm from the probe tip. The distal end was tapered around the tip to simulate a conical tip, similar to that of the cryosurgical probe. The design was similar to the embodiment described inFIG.2. Aluminum was selected as a material with good thermal and electrical conductivity. Therefore, the aluminum did not interfere with heat transfer from the cryosurgery probe. When the power supply was connected to the metal shaft of the cryosurgical probe, the electrical charge became distributed on the outer surface of the aluminum sheet, which served as the electrode and protected the cryosurgical electrode. An experiment was performed in which the cryosurgical probe shaft was connected to the power supply as the anode. The results are shown inFIG.18. The cryosurgical probe/anode1801was inserted in an agar gel made of a physiological saline composition-filled basin1805. The gel was stained with a pH sensitive dye. The cryosurgical probe was inserted to a depth of 3 cm, such that the entire aluminum cover part was inside the gel and only the insulated part protruded from the gel. A copper electrode was inserted circumferentially around the gel1802to serve as the cathode. The cryosurgical probe was operated to freeze the gel until a 5 cm diameter ice ball1804was observed. At the end of freezing a current of 200 mA at 50 V was applied for 10 mins. A variation in color1803was observed. The variation is a result of the pH dye and demonstrates substantial generation of electrolytic products. An experiment was performed in which a coating as described herein was used to protect the cryosurgical probe, which also served as the anode. The results are shown inFIG.19. As seen inFIG.19, partial damage to the aluminum coating on the cryosurgical probe was observed and the tip1900was totally destroyed. However, the cryosurgical probe1901was intact. The outcome of using a coating can be appreciated when comparing the coated cryosurgical probe shown inFIG.19with the un-coated cryosurgical probes that served as anodes as shown inFIG.16. Thus, the coated cryosurgical probes can withstand electrolysis more effectively than un-coated cryosurgical probes. Example 5: Effect of Electrolysis on Heat Shrinking Wrap Coated Cryosurgical Probes A conventional cryosurgical probe was completely wrapped with a thin heat shrinking tube2000having an inner diameter of 2.5 mm and a tube wall thickness of 0.2 mm, as shown inFIG.20. Heat shrinking wrap is ordinarily made of nylon or polyolefin, which shrinks radially (but not longitudinally) when heated, to between one-half and one-sixth of its diameter. The heat shrinking wrap served to electrically isolate the cryosurgical probe from the process of electrolysis. A stainless steel electrode2001having a 2 mm diameter was attached to the cryosurgical probe with an electrically insulating tape2002, leaving 3.5 cm of the distal end of the electrode uncovered. The cryosurgical probe was tested as described in Example 4. As shown inFIG.20, the steel anode2001was partially damaged but the cryosurgical probe was intact. The coated cryosurgical probes can withstand electrolysis. The phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. As used herein, the term “plurality” refers to two or more items or components. The terms “comprising,” “including,” “carrying,” “having,” “containing,” and “involving,” whether in the written description or the claims and the like, are open-ended terms, i.e., to mean “including but not limited to.” Thus, the use of such terms is meant to encompass the items listed thereafter, and equivalents thereof, as well as additional items. Only the transitional phrases “consisting of” and “consisting essentially of,” are closed or semi-closed transitional phrases, respectively, with respect to the claims. Use of ordinal terms such as “first,” “second,” “third,” and the like in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements. Having thus described several aspects of at least one embodiment, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Any feature described in any embodiment may be included in or substituted for any feature of any other embodiment. Such alterations, modifications, and improvements are intended to be part of this disclosure and are intended to be within the scope of the invention. Accordingly, the foregoing description and drawings are by way of example only. Those skilled in the art should appreciate that the parameters and configurations described herein are exemplary and that actual parameters and/or configurations will depend on the specific application in which the disclosed methods and materials are used. Those skilled in the art should also recognize or be able to ascertain, using no more than routine experimentation, equivalents to the specific embodiments disclosed.

11857241

It is noted that the drawings of the disclosure are not necessarily to scale. The drawings are intended to depict only typical aspects of the disclosure, and therefore should not be considered as limiting the scope of the disclosure. In the drawings, like numbering represents like elements between the drawings. DETAILED DESCRIPTION Turning to the drawings,FIGS.1-10provide various embodiments of an ablation probe device and method for using the same. FIGS.1-2depict an ablation probe with integrated deployable sensors, hereinafter referred to as device100. As shown inFIG.1, device100includes a longitudinal body102with a proximal end103and a distal end105. The longitudinal body102integrates a source of thermal energy101therein. As shown in, e.g.,FIGS.1and3, device100may be a cryoprobe, and the source of thermal energy101may include a supply line120(FIG.3) for supplying, for example, nitrogen, argon, carbon dioxide, nitrous oxide, propane, an alcohol solution, or another cryosource as known in the art, either in a gas, liquid, critical, or supercritical state to probe tip106. A return line122(FIG.3) may further be provided for returning used cryosource fluid from probe tip106. In some embodiments, return line122may be in the form of a tube, and may be arranged such that it concentrically surrounds supply tube120. Return line122may itself be concentrically surrounded by an insulative lumen124, which may further be surrounded by outer sheath126of the probe. With reference toFIG.2, in various other embodiments, source of thermal energy101may include any other source of thermal energy known in the art, including, e.g., heat sources such as radio frequency (RF) energy, high intensity focused ultrasound (HiFU), thermoelectric resistive heat, lasers, helium gas, or other energy sources, either alone or in combination with a cryosource. Referring back toFIG.1, longitudinal body102may include a probe tip106disposed at distal end105. During use of device100, probe tip106may be placed at the target tissue site for performing ablation therapy. As further depicted inFIG.1, in embodiments in which device100is a cryoablation device, operation of device100at the target tissue site may cause the formation of iceball107surrounding probe tip106, with an ablation zone108disposed within iceball107. Ablation zone108may include tissue at temperatures as low as, e.g., −196° C. or colder. In other procedures, ablation zone108may include tissue at temperatures in the range of, e.g., −20° C. to −40° C. or colder. Tissues in the range of, e.g., −20° C. to 0° C. may be included within iceball107but may be outside ablation zone108. Iceball107may include a temperature gradient109extending radially outward from probe tip106and ablation zone108. Along temperature gradient109, colder temperatures may be found proximate to probe tip106and in ablation zone108, becoming gradually warmer approaching periphery110of iceball107. Periphery110of iceball107may be about 0° C. It is noted, however, that the thermal transition point that defines the outer edge of the ablation zone and the periphery varies based on the type of tissue targeted. The temperatures provided herein are merely intended to be exemplary. Similarly, in embodiments in which device100is a hyperthermic ablation device, such as shown inFIG.2, operation of device100at the target tissue site heats the target tissue to a point at which lethality is achieved in the tissue surrounding probe tip106. Probe tip106may reach temperatures of upwards of 100° C., and ablation zone108may include tissue heated to temperatures exceeding 40° C., or more particularly in the range of, e.g., 42° C. to 45° C., or 42° C. to 60° C. or higher. Ablation zone108may be surrounded by temperature gradient109extending radially outward from probe tip106and ablation zone108, to a periphery110of the lesion. Temperatures along temperature gradient109may be in the range of, e.g., 42° C. just radially outward of ablation zone108to about 37° C. near periphery110. As discussed above relative toFIG.1, it is noted that the temperatures provided herein are merely intended to be exemplary. As shown inFIGS.1-2, device100may further include a probe handle104disposed at proximal end103of longitudinal body102. In some embodiments, probe handle104may be integrally formed with longitudinal body102. Probe handle104may include control mechanism118for operating device100. In some embodiments, control mechanism118may be a push button for controlling insertion of deployable assemblies114and sensors112(discussed further below) into a designated target tissue. In other embodiments, control mechanism118may include a screw-like mechanism, with the driving force applied manually, or via motor, piston, pneumatics, or other means of causing physical movement of sensors112and deployable assembly114into the tissue. As further shown inFIGS.1-2, a plurality of sensors112are arranged on a deployable assembly114for positioning sensors112in and along the ablation zone108. In some embodiments, deployable assembly114may include a wire or wires encased in a stiff outer covering, which may be plastic, metal, or another material. The stiff outer covering may provide added rigidity to deployable assembly114for guiding the trajectory of sensors112into a target tissue. In the embodiment shown inFIG.1, two deployable assemblies114are illustrated, although in various other embodiments, one, two, or more than two deployable assemblies114may be included in device100. It is noted that each deployable assembly114may be independently operated, both in binary terms of deployment and retraction, and in degree, i.e., deployable assemblies may be deployed at different percentages of their fully deployed extensions. In one example, a first deployable assembly114may be deployed fully, i.e., 100% extended, while a second deployable assembly114may be deployed to only 50% of its full extension. In various embodiments, sensors112on each deployable assembly114may monitor one or more tissue characteristics, such as temperature, pressure, electrical impedance, electrical conduction, blood perfusion, thermal conductivity, thermal diffusivity, sound propagation velocity or another desired metric during the ablation process in both ablation zone108and the surrounding non-target tissues so that collateral damage to the surrounding areas is reduced. In various embodiments, sensors112may specifically be temperature sensors, and may include one or a combination of thermal couples, resistance temperature detectors (RTDs), or solid state temperature devices. Further, sensors may include electrical conduction monitors, tissue impedance rings or point sensors, or acoustic, infrared or other such sensors capable of monitoring the state, functionality, electrical characteristics and temperature within a target tissue prior to during and or following a procedure. In other embodiments, sensors112may record and/or transmit measurements to a user device. As noted, deployable assembly114and its respective sensors112may be used to monitor temperature and other metrics during an ablation procedure at multiple points. During use of device100, deployable assembly114can be positioned at various points within the ablation zone108along and/or across the temperature gradient109to periphery110. Deployable assembly114may be strategically positioned during a procedure to align sensors112with isotherms created during the ablation process. In still further embodiments, deployable assembly114and/or probe tip106may include integrated heating elements to allow for the “thawing” of tissue around probe tip106to facilitate quicker tissue thawing and probe removal following completion of a cryoablation procedure. In various embodiments, deflection wedges116may be provided on a radially outer surface or within the shaft of longitudinal body102of device100. Deflection wedges may be located near the distal end105of longitudinal body102, just proximal of ablation zone108. Deflection wedges116may be configured as described further below to direct deployable assembly114carrying sensors112into the target tissue at a particular angle relative to the probe surface. The specific angles may be calibrated to the desired zones or to locations within a target tissue at a desired distance from the probe tip106following probe insertion into a target tissue. With reference toFIGS.3-5, an embodiment of device100is illustrated in which device100is a cryoablation device including longitudinal body102(FIGS.4-5). As shown inFIG.3, longitudinal body102may include a supply tube120for supplying a fluid thermal energy source to device100, and a return tube122for returning the used fluid thermal energy source. Return tube122may concentrically surround supply tube120, and return tube122may be concentrically surrounded by an insulative lumen124. Insulative lumen124may further be surrounded by probe outer sheath126. At least one integrated guide channel128may be provided within insulative lumen124. In some embodiments, two integrated guide channels128may be provided, and may be disposed approximately 180° around lumen124from one another. Integrated guide channels128may extend along the full axial length of longitudinal body102, as shown inFIGS.4-5. Deployable assembly114, including sensors112, may be disposed within integrated guide channel128between return tube122and outer probe sheath126. As shown inFIGS.4-5, at proximal end103, deployable assembly114may be coupled to insertion mechanism130, which may be coupled to control wiring132, which may in turn be coupled to control mechanism118. As described above, control mechanism118may be, e.g., a push button mechanism. In the retracted position, as shown inFIG.4, each deployable assembly114may be contained substantially within an integrated guide channel128. Upon deployment, shown inFIG.5, deployable assembly114may be extended distally such that sensors112of deployable assembly114are inserted into ablation zone108. With continued reference toFIGS.4-5, distal end105of longitudinal body102may include at least one internal deflection wedge216for guiding the position of deployment assembly114about probe tip106and into ablation zone108. In some embodiments, two internal deflection wedges216may be provided. Internal deflection wedges216may either be an independent member or may be integrated as a portion of distal end105of probe tip106. Internal deflection wedges216include an angled face that extends distally and radially outward, guiding each deployable assembly114distally and radially outward as it is deployed. With reference toFIGS.6-8, a further embodiment of device100is illustrated. As described above relative toFIGS.3-5, the device100shown inFIGS.6-8may be a cryoablation device including longitudinal body102having a supply tube120, return tube122, insulative lumen124, and an outer sheath126arranged in a similar fashion. As best shown inFIG.6, an outer guide channel134may be provided on a radially outer surface of outer probe sheath126. In some embodiments, two outer guide channels134may be provided, and may be disposed approximately 180° around outer probe sheath126from one another. Guide channels134may extend along the full axial length of longitudinal body102, and provide a conduit for deployable assemblies114to extend from proximal end103to distal end105. In the retracted position, as shown inFIG.7, deployable assembly114, including sensors112, may be disposed within outer guide channel134, radially outward of outer probe sheath126. At proximal end103, deployable assembly114may be coupled to insertion mechanism130, which may be coupled to control wiring132, which may in turn be coupled to control mechanism118, similar to the embodiment ofFIGS.3-5. Upon deployment, shown inFIG.8, deployable assembly114may be extended distally such that sensors112of each deployable assembly114are inserted into ablation zone108. Distal end105of longitudinal body102may include at least one surface mounted deflection wedge316for guiding the position of each deployment assembly114about probe tip106and into ablation zone108. In some embodiments, two surface mounted deflection wedges316may be provided. Surface mounted deflection wedges316may be substantially triangular in cross sectional profile, but may also have any other profile shape such that they include a face extending radially outward and distally from a distal end105of longitudinal body102. This face serves to guide each deployable assembly114distally and radially outward as it is deployed. Surface mounted wedges316may further include a base that is mounted or affixed to, or integrally formed with outer probe sheath126. Surface mounted deflection wedges316may either be independent members affixed to longitudinal body102or may be integrated as a portion of distal end105of probe tip106. With reference toFIGS.9-10, another possible embodiment of device100is illustrated. Similar to the preceding embodiments, device100as shown inFIGS.9-10may be a cryoablation device including longitudinal body102having a supply tube120, return tube122, insulative lumen124, and an outer sheath126arranged in a similar fashion. At least one integrated guide channel128may be provided within insulative lumen124. In some embodiments, two integrated guide channels128may be provided, and may be disposed approximately 180° around lumen124from one another. Integrated guide channels128may extend along the full axial length of longitudinal body102as described relative toFIGS.3-5. In the retracted position, as shown inFIG.9, deployable assembly114, including sensors112, may be disposed within integrated guide channel128between return tube122and outer probe sheath126. At proximal end103, deployable assembly114may be coupled to insertion mechanism130, which may be coupled to control wiring132, which may in turn be coupled to control mechanism118as described previously. At distal end105of longitudinal body102, an internal deflection tube416may be provided, at a ratio of one internal deflection tube416for each integrated guide channel128. Internal deflection tube416may be positioned such that a proximal end of internal deflection tube416abuts the distal end of integrated guide channel128, such that deployable assembly114advances distally from internal guide channel128into and through internal deflection tube416as it is deployed into ablation zone108. Internal deflection tube416may guide deployment assembly114into position about probe tip106. In particular, internal deflection tube416may be shaped to direct deployable assembly114in a curve that may be approximately 90° (or other appropriate angle, either more obtuse or more acute) from its trajectory along integrated guide channel128. In particular, internal deflection tube416may deflect deployable assembly114such that a distal end of deployable assembly114bends and curves/extends across a cross section of longitudinal body102in a retracted position, and in a deployed position, extends radially outward at an angle relative to longitudinal body102. For example, in the embodiment depicted inFIG.10, in the deployed position, deployable assembly114extends substantially perpendicularly to longitudinal body102, although an approximate 90° angle is merely exemplary. In some embodiments, sensors112of each deployable assembly114may be positioned within internal deflection tube416in the retracted position, prior to their deployment radially outward of longitudinal body102. With reference to all of the preceding embodiments, independent or integrated internal or surface mounted wedge216,316or deflection tube416configurations may be compatible with any of the device100configurations described above. Further, the angle of the wedge216,316or tube416can vary based on the type of device100, its use and configuration. In one configuration, the wedge216,316angle or tube416angle may be set to allow for a position of sensors112to correspond to regions of critical interest when fully deployed. For instance, in one configuration the wedge216,316angle or tube416angle is set such that sensors112are positioned upon deployment to locations where the desired −40° C., −20° C., and 0° C. isotherms should be achieved by the end of the ablation procedure. In another configuration, the wedge216,316angle or tube416angle may be such that a deployed position of sensors112corresponds with a specific distance from probe tip106. The angle of wedges216,316or tube416may be in the range of about 0° to about 90° to allow sensor deployment within the range of about 0° to about 90° from the probe tip106surface. With reference to all of the preceding embodiments depicted inFIGS.1-10, various arrangements of sensors112may be used in deployable assembly114. In one embodiment, deployable assembly114may be positioned to record measurements at any point along or within the ablation zone108created by use of probe tip106, including areas both along the longitudinal body102and radially outward therefrom. In further embodiments, sensors112may be spaced at varied intervals along the length of deployable assembly114. In some embodiments, such as where sensors112are temperature sensors, one arrangement may include four or five sensors112in each deployable assembly114, each sensor spaced approximately 5 mm from the next sensor. A distal-most sensor112may be positioned at the distal end of the deployable assembly114. In such an embodiment, when deployed as inFIG.1,5,8, or10, the proximal-most sensor112may be immediately adjacent the probe surface. The distal-most sensor112may be 1.5 to 2 cm total from the proximal-most sensor. This may result in a sensing diameter of a 3-4 cm zone of tissue. In another embodiment, which may also be applicable to temperature sensors, a first sensor112may be located at a distal end of deployable assembly114. A second sensor112may be located approximately 2.5 mm proximal of the first sensor112along deployable assembly114. A third sensor112may be located approximately 2.5 mm proximal of the second sensor112along deployable assembly114. A fourth sensor112may be located approximately 5 mm proximal of the third sensor112along deployable assembly114. A fifth sensor112may be located approximately 5 mm proximal of the fourth sensor112along deployable assembly114, placing the fifth sensor approximately 1.5 cm proximal of the distal-most sensor112. This configuration may provide higher resolution at the outer range of the ablation zone108, where the thermal gradient109(FIG.1) tends to be higher. In a further embodiment, sensors112may be arranged as described in the preceding paragraphs, but may include the addition or substitution of one or more electrical conduction sensors for thermal sensors at any of the various points. For example, counting from the proximal end of deployable assembly114, the second or third sensor112may be an electrical conduction sensor for either mono or bipolar electrical conduction recording for use during, e.g., cardiac ablation procedures. It is noted that the foregoing embodiments are intended only to be illustrative, and do not constitute an exhaustive recitation of the possible combinations and arrangements of sensors112. In the various embodiments, both those described above and those specific embodiments not described in the interest of brevity and clarity, the actual distance from the probe into ablation zone108of the sensors112would vary with the extent of deployment of the deployable assembly114. For example, on a deployable assembly114including five sensors112, each sensor112spaced 5 mm from each adjacent sensor112, 100% deployment would result in a 2 cm radius (4 cm diameter) measurement zone, whereas a 50% deployment would result in a 1 cm radius (2 cm diameter) measurement zone. Also provided herein is a method for performing targeted ablation of various tissues such as, e.g., the skin, esophagus, bladder, endometrium, breast, prostate, liver, heart, lung, pancreas, testis, uterus, muscle, bone, kidney, or other tissue, including temperature monitoring during ablation. As shown in, e.g.,FIGS.4,7, and9, device100may initially be in a retracted, non-engaged position in which deployable assemblies114including sensors112are disposed within longitudinal body102of the probe. This positioning of the deployable assemblies114allows for their maintenance and secured positioning during insertion of probe tip106into the target tissue. Upon insertion of probe tip106into the target tissue, the deployable assemblies114may be deployed as shown inFIGS.1,5,8, and10, e.g., by control mechanism118on probe handle104, from the longitudinal body102into the ablation zone108in the tissue. The sensors112are directed into the tissue at a precise angle from the probe surface via deflection wedges216,316or deflection tubes416located at the distal end105of longitudinal body102, just proximal of ablation zone108as described above. In one embodiment, deployment of deployable assemblies114may occur prior to performance of an ablation procedure, in order to facilitate monitoring temperatures or other tissue characteristics once ablation is initiated, and in the case of cryoablation in particular, to avoid maneuvering through ice formation. In another embodiment, deployment occurs during or after ablation procedures. To accommodate desirable monitoring of temperature and other metrics, deployable assemblies114are capable of being positioned before, during, or after treatment. Deployment of the deployable assemblies114and sensors112into the tissue can be directed to any number of locations including, but not limited to, positions of predicted isotherms, to positions where the attainment of a specific temperature is desired, to positions where desired ablation is achieved, and into non-targeted tissue to assure minimal damage within that region. Following completion of the ablation procedure, deployable assemblies114may be retracted into longitudinal body102via use of control mechanism118, and probe tip106can be removed from the tissue. Though ablation device100has been described in terms of particular embodiments, the various embodiments and aspects of the invention may be utilized in various treatment procedures in a patient. The use of a thermal monitoring device benefits current ablative treatment procedures by utilizing a minimal invasive device and technique that achieves a more controlled ablation with greater precision, fewer procedures, and improved patient outcomes. It is noted that aspects of the invention may be varied to accommodate different sizes, shapes and dimensions of probes used in fields of medical devices. Aspects of the invention may also be integrated in fields outside the medical realm as desired. Such fields may include any temperature measurement or monitoring systems. As used herein, the terms “first,” “second,” and the like, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another, and the terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. The modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., includes the degree of error associated with measurement of the particular quantity). The suffix “(s)” as used herein is intended to include both the singular and the plural of the term that it modifies, thereby including one or more of that term (e.g., the metal(s) includes one or more metals). Ranges disclosed herein are inclusive and independently combinable (e.g., ranges of “up to about 25 mm, or, more specifically, about 5 mm to about 20 mm,” is inclusive of the endpoints and all intermediate values of the ranges of “about 5 mm to about 25 mm,” etc. While various embodiments are described herein, it will be appreciated from the specification that various combinations of elements, variations or improvements therein may be made by those skilled in the art, and are within the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.

11857242

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The attachment for a gas-assisted electrosurgical system of the present invention has a housing100, a channel within the housing, a connector (not shown) for connecting said channel to a gas source (not shown), an electrosurgical scalpel or blade200and a connector500for connecting said electrosurgical scalpel to an electrosurgical generator (not shown). A housing100for an electrosurgical blade in accordance with a preferred embodiment of the present invention is shown inFIGS.1A-1H. The housing100has a plurality of section110,120,122, and190, for example, made of plastic, channel170that runs along the length of the housing100and a nozzle or tip130. The sections110,120,122and190may be separate parts, may be telescoping in part or in whole, or may be formed as an integral part such as by molding. The nozzle or tip130has a beveled edge132at its distal end. Further, there may be a ceramic tip134inside and/or extending from said nozzle or tip130. The portion110has structural members such as ridges or grooves111for facilitating gripping of the housing by a user's hand, a beveled proximal end112, and a shoulder114. The proximal portion190of the housing100has a plurality of flanges192having beveled edges194for connecting the housing to an electrosurgical hand piece. The housing100further has a spacer or support134inside the channel170for supporting and electrode. The spacer134has a plurality of openings into the channel170and an opening184for receiving an electrode. A surgical blade in accordance with a preferred embodiment of the present invention is shown inFIGS.2A-2D. The electrosurgical scalpel or blade200is elongated and has a proximal portion210that may be round like a wire or may be flat and a flat or paddle-like distal portion220. The flat or paddle-like distal portion220has a width at least four times its thickness. Tip222of the distal blade portion220is rounded or curved. The thickness of the distal paddle-like portion220is preferably in the range of 0.49 mm-0.55 mm while the width preferably is 2.19 mm-2.25 mm. Preferably the blade200is made of stainless steel with a surface coating230preferably of ElectroBond™ from Surface Solutions Group, LLC. Information regarding such coatings is disclosed in U.S. Pat. Nos. 7,390,326, 7,288,091, 7,147,634. An assembly of a surgical blade200within a housing100in accordance with a preferred embodiment of the present invention is shown inFIGS.3A-3G. The surgical blade, which is an electrode, is inserted into the distal end of the tubing, housing or body100. When the attachment300is assembled, blade200extends down approximately the center of the channel in the housing100to a position near or extending from the distal end of the housing100and the tip130. The ceramic tip136surrounds the blade near the nozzle or tip130and may be inside the nozzle130and/or may extend outside the nozzle130. An assembly400of a surgical blade200in accordance with a preferred embodiment of the present invention is shown inFIGS.4A-4E. The electrode or blade200has elongated proximal portion210and a paddle or blade distal portion220. The connector500and blade200may be formed from the same or different materials. For example, the connector500may be nickel-plated brass and the blade coated stainless steel. Other materials such as tungsten may be used. The connector500is at the proximal end of the blade200. The proximal portion210of the electrode is connected to the distal end514of the connector500at the opening550and extends from the distal end514of the connector500. A metal connector500for a surgical blade in accordance with a preferred embodiment of the present invention is shown inFIGS.5A-5G. The connector500has a connector body510having a beveled or rounded proximal end512and a distal end514. The connector may generally be cylindrical in shape but may have a flat portion516for alignment with an electrosurgical hand piece. The body510has a channel540extending through it and a ridge, shoulder or flange518. When assembled with the housing100and the blade200, the rounded or beveled portion512of the connector500provides a conductive surface for making a connection to connector (not shown) that in turn is connected to an electrosurgical generator (not shown). When assembled with the housing100, the channel540in the connector aligns with the channel170in the housing to allow gas to flow through the channel540in the connector500and into the channel170in the housing. In alternative embodiments, the proximal portion210of the blade200further may have a bend to allow for alignment of the channels in the connector500and the housing100. The foregoing description of the preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiment was chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto, and their equivalents. The entirety of each of the aforementioned documents is incorporated by reference herein.

11857243

DETAILED DESCRIPTION OF THE INVENTION This disclosure generally provides systems and methods for delivering a heated vapor to tissue to ablate the tissue. In some embodiments, a vapor delivery system can be provided which can be configured to deliver vapor to tissue to ablate and destroy cancerous tissue. Systems and methods provided herein can be specifically tailored for providing vapor to prostate tissue to ablate the prostate tissue, including cancerous tissues and cells located in the prostate. In some embodiments, a vapor delivery system can include a needle-like vapor delivery device adapted and configured to access a prostate of a male patient. The needle can be inserted into the prostate trans-perineally, trans-rectally, or trans-abdominally, for example. Vapor can be generated in a vapor generator disposed inside the device, or coupled to the device, and can be delivered through the device into the prostate to ablate the tissue. In another embodiment, the vapor delivery device can be configured to access the prostate trans-urethrally to deliver vapor to the prostate. Specific methods and treatment parameters for prostate cancer therapy with a vapor delivery device will also be discussed. FIG.3illustrates one embodiment of a vapor delivery device300comprising a vapor delivery needle302. The vapor delivery needle302can comprise a rigid shaft made of a material commonly used in medical devices, such as stainless steel, titanium, nitinol, polymer, or the like. In some embodiments, the vapor delivery needle can be a 12-20 gauge needle. In some embodiments, the vapor delivery needle can include a tissue piercing distal tip, as shown. The vapor delivery device300can be connected to a vapor generator304, which can be configured to generate a heated condensable vapor and deliver the vapor to the vapor delivery device. The vapor generator can introduce vapor into a vapor lumen306of the vapor delivery device. The vapor lumen can extend along a length of the vapor delivery device, including along a handle portion308and through the vapor delivery needle302. The vapor delivery needle302can include one or more vapor delivery ports310that permit passage of vapor from the vapor lumen from the vapor delivery needle. In one embodiment, and end of the vapor delivery needle can be a vapor delivery port (like the end of a hose). The vapor delivery ports can have diameters ranging from 0.006 to 0.020″. In some embodiments, the vapor delivery ports can be arranged along a distal portion of the vapor delivery needle, at the end portion of the vapor lumen. The vapor delivery needle can have any suitable diameter with a plurality of vapor ports extending over an axial length of 1 mm to 20 mm. In another embodiment, the vapor ports can extend over an axial length of 0.1 mm to 60 mm. In some embodiments, individual vapor ports can be spaced from 0.5 mm to 5 mm apart. In one embodiment, the vapor ports can be radially symmetric to direct the flow of vapor uniformly about the distal portion of the needle into prostate tissue. In another embodiment, the vapor ports can be radially asymmetric to direct the flow of vapor to one side of the needle, for example to direct the vapor flow inwardly in the prostate tissue and away from the outer prostate capsule. In such an embodiment, the handle and/or proximal needle shaft (not shown) can be configured with markings that indicate the radial orientation of vapor ports. In some embodiments, the vapor delivery ports can be of a uniform shape and size. However, in other embodiments, the ports can include varying shapes and sizes. For example, in one embodiment, ports towards a proximal end of the vapor delivery needle can be larger than ports towards a distal end of the vapor delivery needle. The vapor delivery device can further include a controller that can be configured to control the various parameters of vapor delivery. For example, the controller can be configured to control the generation of vapor including a selected vapor quality, can be configured to deliver vapor for a selected treatment interval, and a selected pressure. The controller can be incorporated into the generator, for example, or can be a separate controller module apart from the generator. The handle portion308of the device can include a button or control feature309that can be actuated to control operation of the device. For example, pushing the button can turn on the device and begin the delivery of vapor. The vapor generator provided can be used to generate and control delivery of a condensable vapor through the vapor delivery device to ablate tissue. The vapor generator can be configured to generate and deliver a vapor media that has a precisely controlled quality to provide a precise amount of thermal energy delivery, for example measured in calories per second. Descriptions of suitable vapor generators can be found in the following U.S. patent application Ser. Nos. 61/068,130; 61/191,459; 61/112,097; 61/112,099; 61/112,103; 12/389,808; 12/555,635, all of which are incorporated herein by reference. FIG.4illustrates is a cutaway view of an inductive vapor generator404that can be used with the vapor delivery systems described herein. The inductive vapor generator can comprise a helically coiled tube or pipe411surrounded by a coil of electrical wire412. The helically coiled tube411can be seen through the cutaway section ofFIG.4. The coiled tube or pipe411can be connected to a fluid source414, which can introduce fluid into the coiled tube or pipe. Electrical energy can be applied to the electrical wire to inductively heat the coiled tube to generate a heated condensable vapor from the fluid inside the inductive vapor generator. The fluid flow in the helical tube or pipe can be converted to vapor instantly with the application of electrical energy to the electrical wire. The condensable vapor can then exit the vapor generator as shown. FIG.5shows another embodiment of a vapor delivery device500. The vapor delivery device is similar to the device shown inFIG.3, and includes a vapor delivery needle502, vapor lumen506, handle portion508, button509, and vapor delivery ports510. The vapor delivery system ofFIG.5, however, includes the vapor generator504incorporated into the device itself, such as into the handle as shown. The vapor generator504can receive fluid from a fluid source514, as shown, or alternatively, a pre-determined amount of fluid can be loaded into the generator or the vapor delivery system prior to therapy. FIG.6Ashows a cutaway view of a vapor delivery device600including an insulating layer616surrounding at least a portion of the vapor delivery needle602. The insulating layer616can comprise, for example, an insulating material with a low thermal conductivity, or alternatively, can comprise a vacuum channel or vacuum sleeve, or an active cooling system comprising a channel filled with a gas or other insulating medium such as a fluid. InFIG.6A, the insulating layer616can extend along a length L of the vapor delivery needle. In some embodiments, the insulating layer616can be tapered so as to reduce in thickness as the layer gets closer to the vapor delivery ports610of the vapor delivery needle. The tapered layer can aid in reducing trauma to tissue when the needle is inserted into tissue. The tapered layer may also form a seal with the tissue that prevents vapor from escaping from the needle entrance hole. In some embodiments, the length of the insulating layer can be chosen depending on the target tissue to be ablated. For example, if the vapor delivery device is intended to deliver vapor trans-perineally to prostate tissue, the length L of the insulating layer can be chosen so as to thermally protect and insulate the intervening tissues between the perineum and the prostate of the patient. FIG.6Bshows another embodiment of an insulating layer616for use with a vapor delivery device600. The insulating layer616ofFIG.6Bcan be a removable sheath that can slide over the vapor delivery needle602. In one embodiment, the insulating layer can comprise a vacuum sheath in which a pair of concentric tubes are attached or connected together and a vacuum is created between the tubes. The insulating layer can then be inserted over the vapor delivery needle to protect tissue from being heated by coming into contact directly with the vapor delivery needle. FIG.7shows one method for treating prostate cancer with the vapor delivery devices described herein. Injection of a heated condensable vapor, for approximately 1 to 20 seconds, can be used for focal ablation of cancerous prostate tissue. Furthermore, injection of vapor media at selected flow rates will not propagate beyond the pseudo-capsule or denser tissue surrounding various regions of the prostate, such as the peripheral zone, thus allowing ablation of a targeted region of the prostate without ablation of adjacent zone tissue. In particular, nerve tissue residing on the outside of the prostate capsule will not be exposed to vapor, and will not be ablated, thereby reducing or eliminating the incidence of incontinence or sexual dis-function. In one embodiment, a vapor delivery device700including a vapor delivery needle702can be positioned in one or more locations the prostate, and can be configured to deliver injections of vapor ranging from 1-20 seconds in each location. In one specific embodiment, vapor can be delivered into the prostate for 9-12 seconds. In the embodiment illustrated inFIG.7, the vapor delivery needle can be inserted trans-perineally into the prostate. In some embodiments, the vapor delivery needle can be inserted into a peripheral zone of the prostate to deliver vapor to the peripheral zone. The needle can be placed in multiple paths in the peripheral zone tissue. FIG.7illustrates schematically a vapor delivery device700with vapor delivery needle702being introduced through the patient's perineum PN spaced apart from rectum R into the patient's prostate P. The system700can be configured to deliver condensable vapor from the needle to the prostate through vapor delivery ports710. Also shown inFIG.7is an insulating layer716, as described above, which can be included around the needle to insulate intervening tissues from heat emanating from the needle. FIG.8is an enlarged schematic view showing the vapor delivery needle being introduced into the prostate P. In this specific illustrative embodiment, the needle is being inserted into the peripheral zone PZ. However, in other embodiments the needle can be inserted into the other regions of the prostate, including the central zone CZ, the transition zone TZ, or the fibromuscular stroma FS. As described above, the vapor delivery system can be connected to a vapor generator704communicating with the vapor delivery needle. The needle702can include an insulating layer or sheath716to prevent the needle shaft from heating tissue along the path of the needle outside of the prostate, with the needle optionally being extendable from the insulating layer. In some embodiments, the insulating layer can comprise an active cooling or vacuum insulation layer. In general, a method corresponding to treatment of prostate cancer comprises introducing a needle into prostate tissue, and delivering vapor through the needle to ablate prostate tissue. In one specific embodiment, the method can comprise inserting the needle into peripheral zone tissue of the prostate, and delivering vapor through the needle to ablate peripheral zone tissue of the prostate without ablating non-peripheral zone tissue of the prostate. The method can include introducing the vapor delivery needle into both the first and second prostate lobes. The method can also include positioning the needle in a plurality of locations in the prostate tissue prior to delivering vapor into the prostate. In some embodiments, the method can include introducing the needle under imaging guidance such as ultrasound guidance. Vapor entering the prostate has a lower density than surrounding tissue, thereby showing up as a brighter region in an ultrasound image. Real time ultrasound imaging, such as TRUS (Trans-Rectal-Ultrasound), can be used to image vapor entering the prostate from a trans-perineum or trans-urethral needle placement. In one embodiment, a method of treating prostate cancer can comprise delivering vapor from vapor delivery needle having a plurality of vapor delivery ports to ablate prostate tissue and form a plurality of lesions in the prostate. Lesions in tissue can be determined by treatment and dosing. Focal lesions can be lesions having a size of 1-10 mm, and can be created by delivering less than 150 calories of vapor into the tissue, or by delivering vapor from 2-20 seconds. Regional lesions can be lesions having a size greater than 10 mm, and can be created by delivering between 150-300 calories of vapor into the tissue, or by delivering vapor from 10-40 seconds. Zonal lesions can be lesions that cover a majority (e.g., greater than 75%) of a specified zone of prostate tissue (e.g., peripheral zone), and can be created by delivering between 300-1000 calories of vapor into the tissue, or by delivering vapor from 20-60 seconds. In one embodiment, the method includes the injection of condensable vapor, and more particularly the vapor delivery step includes vaporizing a flow of fluid having a flow rate ranging from 1 cc/min to 60 cc/min to thereby provide the condensable vapor. The method can include injecting vapor media for between 1-20 seconds for a focal ablation site. The delivered vapor media can be configured to deliver less than 150 calories for a focal ablation site. The method can include delivering vapor media configured for regional ablation of abnormal tissue, wherein the vapor media is configured to deliver between 150 and 300 calories for each peripheral zone lobe. The method can include delivering vapor media configured for zonal ablation of abnormal tissue, wherein the vapor media is configured to deliver between 300 and 1000 calories for each peripheral zone lobe. In another embodiment, the vapor media can be injected into peripheral zone tissue at pressure and flow parameters that result in the vapor media being reflected by barrier tissue surrounding the peripheral zone lobe to thereby ablate said lobe without ablating non-peripheral zone tissue. A method for treating prostate cancer comprises delivering vapor media into peripheral zone lobe in a prostate, wherein the vapor media is configured to deliver between 40 and 800 calories to the peripheral zone lobe to thereby ablate malignant tissue with the volume of vapor media being adapted for ablation of the entire peripheral zone lobe. Another method comprises delivering vapor media into peripheral zone lobe in a prostate wherein the vapor media is configured to deliver less than 150 calories to a site in the peripheral zone lobe to thereby cause focal ablation of malignant tissue. FIG.9shows one embodiment of a vapor delivery device900configured to access the prostate trans-urethrally. Vapor delivery device900can have an elongate shaft902configured for insertion into the urethra of a patient and a handle portion904for gripping with a human hand. The vapor device900can include a vapor delivery needle906configured to extend from a distal portion of the elongate shaft902. The vapor delivery needle can extend generally perpendicular to or transverse from the shaft, and can include one or more vapor delivery ports configured to deliver a flow of vapor from the needle into prostate tissue. The vapor delivery device900can be connected to a light source940, a vapor source250, a controller255, an aspiration source320, and a fluid source914. In one method, the trans-urethral vapor delivery device ofFIG.9can be inserted into a urethra of a patient, a needle of the vapor delivery device can be extended into the prostate, and vapor can be delivered from the device into the prostate to treat prostate cancer. In one specific embodiment, the needle of the vapor delivery device can be extended from the urethra, through the transition zone, and into the peripheral zone. Vapor can be delivered from the device into the peripheral zone tissue to treat prostate cancer. FIG.10is a cutaway view of the device900ofFIG.9with the vapor delivery needle906extended into the prostate from the urethra U. As shown, the needle is inserted into one of the two lobes of the prostate, which are separated by imaginary mid-line ML. Although the needle is shown inserted into the transition zone TZ of the prostate, it should be understood that the needle can also be extended into the other regions of the prostate, including the peripheral zone or the central zone. Upon delivering vapor from the needle into the prostate, the ablation zone425can be seen in the Figure. The size and depth of the ablation zone can be controlled depending on the duration of vapor delivery and the amount and quality of vapor delivered. FIG.11shows a method similar to that shown inFIG.7above. However, inFIG.11, a temperature probe718is also inserted through the perineal tissue and advanced towards the prostate. Instead of piercing the prostate with the temperature probe, as is done with the vapor delivery needle, the temperature probe can be placed on an outside surface of the prostate, such as along the outside of the peripheral zone of the prostate, or can be placed in tissues surrounding the prostate. In one embodiment, saline can be injected into the tissues in which the temperature probe is placed (either before or after insertion of the temperature probe) to act as a heat sink. Vapor can be delivered into the prostate with vapor delivery needle702, as described above, and the temperature can be monitored with the temperature probe718. Vapor delivery can then be terminated when the monitored temperature reaches a desired level. In one embodiment, vapor can be delivered into the prostate with the vapor delivery needle until an exterior portion of the prostate reaches a temperature of 47-52 degrees C. Temperature probe718can comprise a singular or linear array of temperature sensors such as thermocouples, with vapor therapy terminated when any sensor in the array exceeds a predefined limit. Temperature probe718can comprise an array of ultrasound transducers which produce a three dimensional ultrasound image of surrounding tissue. The ultrasound array image may provide a temperature map of tissue in addition to guiding needle placement within tissue. FIG.12illustrates a flow chart1200to describe the various methods described above. At step10of flowchart1200, a vapor delivery needle can be inserted into the prostate of a patient. The needle can be inserted into the prostate trans-perineally (FIGS.7and11), trans-urethrally (FIG.10), trans-rectally, or trans-abdominally. Any of the vapor delivery devices described herein can be used for this method step. In some embodiments, the vapor delivery needle can be inserted into a peripheral zone of the prostate. In other embodiments, the needle can be inserted into a transition zone, or alternatively, into a central zone of the prostate. Next, at step12of flowchart1200, the method can optionally include insulating non-prostate tissues from the vapor delivery needle with an insulating layer or sheath around a portion of the vapor delivery needle. Embodiments of an insulating layer or sheath are found inFIGS.6A-6Babove. Next, at steps14and16and of flowchart1200, vapor can be delivered from the vapor delivery needle into the prostate, and delivery of vapor can be terminated when the desired ablation of prostate tissue is achieved. In some embodiments, vapor can be delivered for a period of between 1-60 seconds to ablate the prostate tissue. Alternatively, in another embodiment the vapor can be delivered for a period of between 9-12 seconds. In some embodiments, ablating the prostate tissue comprises ablating prostate cancer tissue. In one embodiment, ablating prostate tissue can comprise ablating peripheral zone tissue without ablating non-peripheral zone tissue. In one embodiment, the temperature of the prostate, or the temperature of tissue just outside the prostate (e.g., the connective or fatty tissues, or the nerves surrounding the prostate, or the prostate capsule) can be monitored (as described inFIG.11) and therapy can be terminated when the prostate reaches a desired temperature (e.g., 44-60 degrees C.). In one embodiment, the desired temperature of monitored outer boundary of the ablation is approximately 48 degrees C. Finally, at step18of flowchart1200, the vapor delivery needle can be withdrawn from the prostate after the therapy is completed. In some embodiments, the needle can remain hot while being withdrawn so as to seal the prostate and intervening tissues as the needle is withdrawn. In another embodiment, the needle can continue to release a flow of vapor as the needle is withdrawn, to seal the prostate and intervening tissues. The “hot” needle, or continuing to release vapor as the needle is withdrawn can kill cancer cells and prevent “seeding” or spreading of cancer cells into non-cancerous tissue as the needle is withdrawn. This disclosure describes a vapor delivery system for ablating tissues of the prostate that has a number of unique advantages over other energy modalities. First, systems described herein benefit from a reduced procedure time. In some embodiments, vapor therapy of the prostate comprises one or more short (<12 sec) treatments of vapor delivery. Other energy modalities, such as RF, microwave, ultrasound, laser, radiation seeds, or surgical resection require much longer treatment times. The shorter procedure times provided by vapor therapy allow for less chance of collateral damage, and less time for heat conduction to, and thermal damage of, adjacent tissues. Vapor therapy also provides for reduced energy application, which enables the shorter treatment time described above. Vapor therapy provides very little excess energy that can cause collateral damage. Furthermore, vapor therapy provides thermal ablation of tissue with a limited maximum temperature. Vapor temperature is nominally .about.100.degree. C. Interstitial tissue pressure may be around 1 psi (50 mm Hg), and vapor at 1 psi (gauge pressure) has a temperature less than 102.degree. C. Vapor will condense only on tissues having temperature lower than steam temperature. Therefore, in vapor therapy, tissue temperature is equal to or less than the temperature of the vapor. The result of vapor therapy in tissue is that tissue remains moist with to no charring or scaring, such as is found in RF or other ablative technologies. Furthermore, tissue treated with vapor therapy can be completely absorbed by the body over time. The other thermal therapies mentioned (e.g., RF, ultrasound, laser, etc.) have no tissue temperature limit, so tissue treated with these modalities can be desiccated, charred, or encapsulated with scar formation. Heat can also be conducted with these modalities to adjacent tissue at higher temperatures, causing increased collateral damage. Vapor therapy is contained within the prostate capsule or desired prostate zone capsule. Vapor does not pass through the capsule tissue that surrounds the lobe or each prostate zone being treated. Additionally, tissue constricts around a vapor delivery needle, preventing vapor escape. The capsule tissue has reduced thermal conductivity, thereby insulating surrounding tissue from treated prostate tissue. Untreated tissue surrounding the prostate capsule is perfused with blood. Perfusion efficiently removes heat, keeping the outside surface of the capsule at a significantly lower temperature than treated tissue within the capsule, preventing necrosis on or outside the capsule, and preventing nerve damage. The prostate capsules are not a barrier to other ablation therapies. The electrical properties of the capsule and surrounding tissue are similar to those of the prostate, allowing ablation current to cross the prostate capsule in RF, microwave and other electromagnetic or radiation therapies. The capsule does not contain ultrasound vibrational energy, and does not confine cryotherapy. Mechanical therapies can readily cross the boundaries of the capsule. Furthermore, vapor can fill a treatment volume, even when delivered from a small source, such as a vapor delivery needle. Vapor can penetrate through the spaces around cells in the prostate. Thermal diffusion through the tiny cell volume occurs in a few milliseconds, so tissue through which steam has passed can be rapidly elevated to ablation temperature. Vapor will not condense on tissue already at 100.degree. C. Intercellular spaces constrict when vapor condenses. Vapor will therefore take the path of least resistance and lower temperature through intercellular spaces that do not already contain condensed steam. Lesions are therefore spherical in vapor therapy. Vapor will continue to condense on any tissue that is below steam temperature as it moves radially outward into tissue. At the end of vapor therapy, heat can be conducted to surrounding tissue. If this tissue is perfused, conducted heat may be carried away, keeping the tissue surrounding the ablation zone below ablation temperature. The volume of a lesion from vapor therapy can be therefore predicted by the energy content of the vapor (mass of fluid delivered as vapor times its heat of vaporization) which is equal to the volume of the lesion times the prostate tissue specific heat (Joules/cm.sup.3.degree. C). times the difference between vapor temperature 100.degree. C.) and body temperature (.apprxeq.37.degree. C.). For vapor delivered at a constant rate, the volume of the lesion is simply proportional to the delivery time. Although particular embodiments of the present invention have been described above in detail, it will be understood that this description is merely for purposes of illustration and the above description of the invention is not exhaustive. Specific features of the invention are shown in some drawings and not in others, and this is for convenience only and any feature may be combined with another in accordance with the invention. A number of variations and alternatives will be apparent to one having ordinary skills in the art. Such alternatives and variations are intended to be included within the scope of the claims. Particular features that are presented in dependent claims can be combined and fall within the scope of the invention. The invention also encompasses embodiments as if dependent claims were alternatively written in a multiple dependent claim format with reference to other independent claims.

11857244

DETAILED DESCRIPTION Certain details are set forth below to provide a sufficient understanding of embodiments of the disclosure. However, it will be clear to one skilled in the art that embodiments of the disclosure may be practiced without these particular details. Moreover, the particular embodiments of the present disclosure described herein are provided by way of example and should not be used to limit the scope of the invention to these particular embodiments. In other instances, well-known materials, components, processes, controller components, software, circuitry, timing diagrams, and/or anatomy have not been described or shown in detail in order to avoid unnecessarily obscuring the embodiments. This disclosure describes tissue ablation systems and methods that may utilize certain pulse designs and operation protocols that may advantageously allow for tissue ablation using the combined effect of electroporation with electrolysis. Combining electroporation with electrolysis may produce a substantial increase in the extent of tissue ablation as compared to the ablation produced by the same dose of electrolysis or electroporation separately. Without being bound by a particular theory, this phenomenon may be attributed to the electrolytically produced chemicals that may pass through a permeabilized cell membrane into the interior of the cell, thereby causing cell damage at much lower concentrations of electrolytic products than for intact cells. This mechanism of tissue ablation may be affected by the dose of chemical species produced by electrolysis at the electrodes, the process of electro-osmotic diffusion from the electrodes into tissue and the permeabilization of the cell membrane in the targeted tissue. Moreover, electroporation had previously been performed using a series of short (e.g. on the order of nanoseconds to milliseconds) voltage or current square-like pulses. This repetitive pulsing may cause repetitive, with each pulse, muscle contractions in the tissue, which may be or become violent muscle contractions such that the technique would be required to be performed under general anesthesia with paralyzing drugs. Moreover the products of tissue electrolysis generated during the delivery of the pulses may cause the formation of a gas layer around the electrodes which for square like pulse shapes yield ionization of the gases and a violent and uncontrollable electric discharge across the gas layer. Moreover, the repetitive pulsing for short times at high magnitudes (e.g. over 90 pulses at 1500V/cm) may cause mechanical stress in the tissue, which may be severe and could damage delicate tissues such as prostate, brain, or bone. Pulse designs and operation protocols are described herein which may reduce these undesirable effects. For example, application of a single voltage or current pulse that may be of a longer (e.g. on the order of milliseconds to seconds to minutes) duration but a lower voltage or current, and with a gradually decaying form, e.g. exponential decay may advantageously reduce or prevent the violent muscle contractions seen previously, while avoiding the electric discharge and allowing the time necessary for electrolysis products to diffuse into tissue to be effective in enhancing the tissue ablation. Electrolysis generally refers to a process of inducing a chemical reaction that involves passing a direct current through an ionic solution via two electrodes. Electrolysis may facilitate the removal and/or addition of electrons from atoms and/or ions, which may lead to the formation of new products. For example, by passing a DC current through a saline solution (NaCl and H2O), hypochlorous acid (HClO) may be formed. The products formed may be based, at least in part, on the ionic composition of the solution, and/or its pH. The amount of electrolysis products formed may be based at least in part on the magnitude of the current and/or the duration the current is applied. The current may be generated by coupling a power source to the electrodes. Examples of power sources may include, but are not limited to, one or more, electrical network, batteries, a computer (e.g., coupled via universal serial bus (USB) cable), a solar cell, and combinations thereof. In some embodiments of relevance to this patent, electrolysis may be used in combination with electroporation for inducing cell death in tissue. The combination treatment may be more effective at ablation and/or sterilization than the individual treatments used alone. The combination of electrolysis with electroporation in use for tissue ablation may generally be referred to as E2 herein. FIG.1Ais a schematic illustration of various domains for electroporation and electrolysis. The illustration shown inFIG.1Ais given as electric field strength versus time. WhileFIG.1Ais provided as an example of a typical curve, its characteristics (e.g., slope) may change with cell type. The values given on the axis are typical to mammalian cells. The time range for irreversible electroporation may be from nanoseconds to minutes and the voltage range may be from several hundred V/cm (200 V/cm) to 100 V/cm. For reversible electroporation that voltage range may be from 50 V/cm to several hundred V/cm (500 V/cm) and the time range may also be from nanoseconds to several minutes. Electrolysis may occur when current flows from electrodes to tissue (electrons to and from ions) and/or when the voltage exceeds a certain threshold prescribed by the electrochemical potential of the electrodes in relation to the solution. This threshold value may depend on the electrode material, composition of the solution, pH, and/or temperature. Typical values may be several volts, for example from 0.01 V to 10 V. InFIG. A1, the curve that displays values in which electrolysis products cause cell death may include multiple regions. That curve may include regions in which cell death may be caused by electrolysis alone, by combination of reversible electroporation and electrolysis, and/or combination of irreversible electroporation and electrolysis. We define the domain above the electrolysis cell death curve for electric fields above the reversible electroporation curve and above the irreversible electroporation curve E2. Confirming if a tissue ablation protocol is included in the E2 region or not may be done by determining if cell death in that region occurs even when the products of electrolysis are eliminated, while the other parameters remain unchanged. The diagram illustrated inFIG.1Ais schematic. However, it illustrates that the minimal time of exposure required for cell death with involvement of electrolysis may increase in the following order: a) combination used from irreversible electroporation with electrolysis to b) reversible electroporation with electrolysis to c) electrolysis alone. As shown inFIG.1A, the electrolytic involvement cell death curve may only have a lower limit, since electrolysis may occur in the presence of a process that involves transfer of electrons to ions, but may not always cause cell death. Typical times for IRE+E are single microseconds (e.g., approximately 0.1 microsecond-1 microsecond) and for RE+E are several tens of microseconds (e.g., 10 microseconds) and for E are seconds (e.g., 1 sec). For a given electric field strength, the electric field applied for over a threshold time may generate sufficient electrolysis to enable cell death to occur. The threshold amount of time required may vary based on the electric field strength used. Accordingly, as seen inFIG.1A, there may be at least five domains—a region of reversible electroporation only (RE), a region of irreversible electroporation (IRE) only, a region of reversible electroporation plus electrolysis (RE+E), a region of irreversible electroporation plus electrolysis (IRE+E), and a region of electrolysis without electroporation (E). As used herein, the regions of IRE+E and RE+E are referred to as E2. Tissue ablation may be performed using the desired techniques (e.g. IRE, RE, E, IRE+E, or RE+E) by selecting a field strength and time associated with the domain of interest. An example method of tissue ablation through the delivery of products of electrolysis to a targeted volume of tissue, in combination with the permeabilizing of the cell membrane of the cells in targeted volume of tissue may include, bringing electrode needles to the proximity of the interior and/or exterior of the targeted volume of tissue, delivering electric potential to the electrodes to generate electric fields that permeabilize the cell membrane in the targeted volume of tissue, delivering electric current to the electrodes for generating the electrolytic products at the electrodes at an amount sufficient to ablate permeabilized cells in the targeted volume of tissue, and electro-osmotic diffusion of the electrolytic products throughout the targeted volume of tissue. Permeabilization and production of electrolytic products may be done in any sequence that achieves the goal of bringing the products to the cells in the targeted volume of tissue and at the same time permeabilizing these cells, such as permeabilizing the volume of cells in tissue first and generating the required amount of products of electrolysis next, generating the amount of electrolytic products first and permeabilizing the cell membrane next, permeabilizing the volume of cells first, generating the required products of electrolysis next and then permeabilizing the volume of cells again, simultaneously permeabilizing the cell membrane and producing the products of electrolysis, or any combination of these. The electrodes brought to the proximity of the tissue can serve for both electrolysis and electroporation or some of the electrodes may be dedicated for electroporation and others for electrolysis. FIG.1is a schematic illustration of a multimodality electrolysis system100according to an embodiment of the disclosure. The multimodality electrolysis system100may be capable of performing electrolysis and at least one other treatment, such as cellular permeabilization treatment. Although the system100inFIG.1is shown on the surface of a tissue10, the system100may be configured to be used inside tissue10, proximate tissue10, and/or in a cavity formed by tissue10in some embodiments. In some embodiments, the system100may include a controller105coupled to an electrolysis device110and a cellular permeabilization device115. The cellular permeabilization device115may also be referred to as a cellular electroporation device. Although shown as separate devices in some embodiments the electrolysis device110and the cellular permeabilization device115may be the same device. The devices110,115may be placed proximate to a treatment site on tissue10, either in the interior and/or the exterior of the treatment site The controller105may control the timing, strength, and duration of treatments provided by the devices110,115. The controller105may, for example, be programmed to provide an electronic signal to the devices110,115. The electronic signal may be indicative of a dose of treatment, for example, a dose of electrolysis products. The electronic signal may control the timing and magnitude of a current generated by the electrolysis device110and/or the cellular permeabilization device115, which may be implemented as an electroporation device. This may allow a user to customize treatment of the tissue10. In some embodiments, the controller is coupled to a power supply120. In some embodiments, the power supply120may be included in device110and/or device115. In some embodiments, the power supply120is integrated with controller105. Although shown as a separate component coupled to the devices110,115, in some embodiments, the controller105may be integrated into one or both devices110,115and/or packaged together with one or both devices110,115. In some embodiments, the controller105may include a programmable chip coupled to the devices110,115. Some embodiments, the controller105may be implemented using a computing device (not shown) and be remotely coupled to the devices110,115. The computing device may be implemented using, for example, a desktop, laptop, server, handheld device, a personal computer, a tablet computer, and/or a smart phone. In some examples, the computing device may be integrated with and/or shared with another piece of medical equipment. The controller105may be coupled by a wire or communicate with the devices110,115wirelessly. In some embodiments, two separate controllers may be used in system100. Each controller may be coupled to one of the devices110,115. In some embodiments, the controller105may be programmed to provide an electronic signal indicative of a dose of the electrolysis products and/or a permeability level of cells. The controller105may, for example, include such a program, or include one or more processing devices (e.g. processors) coupled to a memory encoded with executable instructions for electrolysis treatment and at least one other treatment, such as cellular permeabilization treatment. The system100may further include one or more sensors for measurement of pH125, electronic field strength or/and electric current130, and/or other properties of the tissue10. For example, the sensor may sense pH near the electrolysis device110and provide the pH value to the controller105. The controller105may further be programmed to adjust an electronic signal provided to the electrolysis device110based on the pH near the device. A reservoir (not shown) may be provided for addition of compounds, such as buffers or other solutions, to the tissue to adjust the pH. In another example the pH sensor125, may be inserted at the outer edge of the targeted volume of tissue to detect when the pH at the site has reached a desired level which may ensure the ablation of tissue at that site. This may be used as an indicator by the controller105to stop the electrolysis process. In another example the pH sensor125, may be inserted at a particular site in tissue to detect when the pH at the site is reaching a potentially damaging value to avoid tissue damage at that site. This may be used as an indicator by the controller to stop the electrolysis process. In some examples the electric meter130may be set at a particular location in tissue to measure isoelectric field levels which may ensure that the cells at that location are permeabilized. The electric meter130may be implemented as an electrical conductivity meter. In some embodiments, the electrolysis device110includes one or more electrodes for conducting a current through a solution. The solution may be native to the treatment site and/or it may be introduced to the treatment site. In some embodiments, the electrolysis device110includes an aqueous matrix in contact with the electrodes for placement proximate the treatment site. In some embodiments, the aqueous matrix may be a gel including a saline solution. In some embodiments, the electrolysis device110may include needle electrodes and/or a catheter for use within cavities and/or tissues. The cellular permeabilization device115may perform reversible and/or irreversible permeabilization. In some embodiments, the cellular permeabilization device115is an electroporation device. The electroporation device may include one or more electrodes for conducting a current through a tissue for permeabilizing cells. The permeability of the cells and/or the reversibility of the permeabilization may be based, at least in part, on the magnitude of the local electric field in tissue and/or duration of the electroporation treatment. In some embodiments, the cellular permeabilization device115is a sonoporation device, which may use ultrasound for permeabilization. In some embodiments, the cellular permeabilization device115may implement another permeabilization method such as, but not limited to, cryosurgery, freezing, coldporation, heatporation, and chemoporation. In some embodiments, electrolysis device110may be packaged with the cellular permeabilization device115. In some embodiments, the electrolysis device110and cellular permeabilization device115may be a single device. For example, the electrodes for performing electrolysis may also be used for performing electroporation. For example, the electrolysis device110and the cellular permeabilization device115may in some examples be implemented using a single device, e.g. a device including an electric field generator which may include a voltage or current supply. The controller105and/or the device combining electrolysis device110and115may provide one or more voltage or current pulses to the tissue10sufficient to have operation in the desired domain of electroporation and/or electrolysis. In some examples, a single pulse of voltage and/or current may be provided to the tissue10and may cause both cell death through reversible or irreversible electroporation and cell death through electrolysis. It has been observed that a single pulse of voltage or current may be advantageous over multiple pulse examples in some situations, because the single pulse may, for example, reduce severe muscle contractions and/or sparking. FIG.1Bis a schematic illustration of a pulse design in accordance with an example of the present disclosure. The pulse shown inFIG.1Bmay be applied by the device110and/or115in some examples, and may be specified by the controller105in some examples. Generally, the pulse may have three components—a rising edge, labeled F1, a plateau, labeled F2, and a falling edge, labeled F3. Use of a single pulse (as opposed to repeated pulses) during which electroporation and electrolysis may occur may be advantageous in some examples. The pulse may be of a variety of different shapes, including but not limited to an exponential decay, a square wave, a triangle wave and wave with a rising leading edge or falling trailing edge. Generally, the rising edge F1may rise to a voltage sufficient to induce reversible or irreversible electroporation electric fields throughout the targeted treated domain. Example values for reversible electroporation include, but are not limited to voltages above 100 V/cm and for irreversible electroporation, voltages above 400 V/cm, as shown inFIG.1A. The rise may be between nanoseconds and seconds. The plateau portion F2may last long enough that together with the rise time and decay time, it produces the desired electroporation effect. However, it may be desirable that the plateau portion F2is short enough to eliminate the electric discharge across a gaseous layer that may develop near the electrodes. In some embodiments, the plateau may be infinitesimally small. The decaying edge F3may decay so that the electric field across the electrolytic gas layer that may form near the electrodes is less than the ionization field of about 30,000 V/cm to avoid sparking, but provides an adequate voltage long enough to produce the desired products of electrolysis for tissue ablation. In some embodiments, the rising edge F1, plateau portion F2, and/or falling edge F3of the pulse may be designed so that ablation occurs primarily or exclusively from electroporation rather than electrolysis. FIG.1Cis a schematic illustration showing a pulse design in accordance with examples described herein overlaid on a conventional pulse design. As can be seen inFIG.1C, a decaying edge of a pulse (which may have no or a negligible plateau and rising edge as seen inFIG.1C) may have exponential decay. The pulse may have a magnitude which is instantaneously, or briefly, above the magnitude of a conventional electroporation pulse sequence. However, the exponentially decaying pulse decays from that higher value to avoid the electric discharge across the electrolytically formed gas layer and may provide an electric field for a longer period of time to generate electrolytic products in a sufficient quantity for tissue ablation. In some embodiments, the magnitude of the pulse and the exponential decay may be selected so that ablation occurs primarily or exclusively from electroporation rather than electrolysis. In some embodiments, regardless of the IRE zone in which it is used, a decaying pulse may produce cell death with much less muscle contraction for the same zone of ablated region—e.g. in all the IRE and the IRE+E and RE+E regions. The pulse can also be designed to eliminate electric discharge from the electrodes. The shape of the pulse can be optimized for the desired effect. For example, during conventional pulsed square electroporation, the start of the pulse may initiate the permeabilization of the cell membrane. However, the subsequent pulses while aiding to the cell membrane permeabilization may also produce substantial electrolytic products which after some number of pulses may produce a layer of gas around the electrodes. If the voltage of the electroporation pulses is sufficiently high and the gas layer is thin (as it may always be when the process starts), an ionization process of the gas occurs. This generates an electrical discharge across the ionized gas layer, associated with high pressure waves. However, if a decaying pulse is used for electroporation, this pulse has the ability to retain and even enlarge the permeabilizing pores. However, since the voltage decays, even when an electrolytically produced gas layer forms around the electrodes the voltage at that time may be low enough to avoid the production of sparks. An example numerical value for electric fields that develop across a gas layer to generate an electric breakdown and the consequent sparks may be approximately 30 kV/cm. Therefore, as long as the relation between the rate of production of electrolytic compounds and the gas layer and the voltage at the electrodes is lower than this value, there may continue to be electroporation and electrolysis without an electrical discharge across the gas layer. In some embodiments the combination electrolysis and permeabilization may be combined with other modalities for tissue treatment such as thermal ablation, radiation, chemical ablation, and/or gene therapy. FIGS.2A and2Bare flow charts illustrating methods200A,200B according to embodiments of the disclosure. In some embodiments, a multimodality electrolysis system, device, and/or apparatus may be placed for treatment of a target site, for example, a tissue. The multimodality electrolysis system such as the system100illustrated inFIG.1may be used. The E2 treatments performed by the multimodality electrolysis system may be manually controlled by a user or may be controlled by a controller, for example, controller105shown inFIG.1. FIG.2Aillustrates a method of a generating a pulse, for example, the pulse illustrated inFIG.1B, according to an embodiment of the disclosure. At Block205, an initial voltage may be applied. The initial voltage may be applied to a treatment site with an electrode by transmitting an electrical signal to the electrode with a controller. The controller may be controller105shown inFIG.1in some embodiments. The initial voltage may be chosen to be sufficient to induce electroporation at the treatment site. In some embodiments, the current across the treatment site may be monitored, for example, by an electric meter such as electric meter130shown inFIG.1. Once electroporation has occurred, the electric meter may detect changes in current as cellular permeabilization occurs. For example, the current may increase during permeabilization. The electric meter may also or alternatively detect changes in current as a gas layer accumulates due to formation of electrolytic products. For example, after the initial current increase after permeabilization, the electric meter may detect a decrease in current as the gas layer accumulates at the treatment site. The electric meter may provide the detected current as a current measurement to the controller. At Block210, the voltage may be adjusted based on the current. The controller may transmit a signal to the electrode to reduce the voltage applied to the treatment site responsive to the detected current. The controller may maintain the reduced voltage or decay the voltage based on the desired width of the pulse. In some embodiments, a pH meter may monitor the pH of the treatment site. For example, the pH meter125shown inFIG.1. The pH meter may transmit the detected pH at the treatment site to the controller. At Block215, the voltage may be adjusted based on the pH. The controller may adjust the decaying voltage of the treatment pulse based, at least in part, on the detected pH. For example, the controller may adjust the decay of the voltage applied to the treatment site to maintain a desired pH for a desired amount of time. In another example, the controller may adjust the decay of the voltage applied to the treatment site so that the voltage level is maintained until a desired pH at the detection site is reached. The maintained voltage may be kept below the voltage required to induce sparking. The method described inFIG.2Amay produce a single pulse that may be adjusted based on the detected parameters. In some embodiments, only Block210or Block215may be present. In some embodiments, Block210and215may be performed simultaneously. In some embodiments, the order of Blocks210and215may be reversed. In some embodiments, the voltage may be adjusted based on other parameters. For example, an imaging modality may transmit a signal to the controller when a color change associated with treatment is detected. FIG.2Billustrates a method200B of a generating a pulse, for example, the pulse illustrated inFIG.1C, according to an embodiment of the disclosure. A capacitance may be charged to an initial charge at Block220. The capacitance may be charged responsive to a signal from a controller. The controller may be controller105shown inFIG.1in some embodiments. The charge in the capacitor may be discharged to apply a voltage at Block225. An initial voltage may be applied to a treatment site with an electrode by transmitting an electrical signal to the electrode with the controller and/or coupling the electrode to the capacitance with the controller. The initial voltage may be chosen to be sufficient to induce electroporation at the treatment site. The initial voltage may then decay. Other than initiating the application of the pulse to the treatment site, the controller may not further alter shape of the pulse in some embodiments. In some embodiments, the electrical signal may be provided by a resistance and a capacitance coupled to a power supply. The capacitance and resistance may be selected to provide the desired initial voltage and time constant for the decay of the voltage pulse. The power supply may charge the capacitance, and responsive to the electrical signal of the controller, the capacitance may discharge through the resistance and the electrode to apply the pulse to the treatment site. Other methods other than those described in methods200A-B may be used to generate a single pulse to apply to a treatment site. For example, a function generator may be coupled to the electrode. The function generator may be coupled to the controller or controlled manually by a user. In some embodiments, electrolysis and cellular permeabilization may be performed at the same time or partially at the same time. For example, current to generate electrolysis products may be provided during a same period of time as an electric field for electroporation, or current as a thermal source for permeabilizing cell membranes is applied to the tissue. In some embodiments, electrolysis and cellular permeabilization may both be performed together for a continuous period of time or intermittently. A pulse of current and/or voltage may be designed to cause the combination of electroporation and electrolysis that is desired in some examples. For example a continuous single pulse can be applied to deliver concurrently electrolysis and electroporation. The single pulse may be of a variety of different shapes, including but not limited to an exponential decay, a square wave, a triangle wave and wave with a rising leading edge or falling trailing edge. The single continuous pulse eliminates disruption of generation of electrolytic species that occurs with multiple pulse delivery configurations. In some embodiments, the single pulse is delivered at the range sufficient to cause irreversible electroporation but not sufficient to cause any significantly contributing electrolytic species production that may cause electric discharge across the electrolytically produced gas layer. This configuration allows for tissue ablation in the non-electrolytic irreversible electroporation domain. In some embodiments, one treatment may be performed continuously while the other treatment is performed intermittently. The magnitude and duration of each treatment may be modulated independently of the other treatment. For example, electrolysis may be performed continuously for several minutes while cellular permeabilization may be performed for several seconds each minute. The electrolysis may be discontinued while the cellular permeabilization continues to be performed. Other combinations of treatments may be possible. The time, duration, and order of the treatments may be chosen based at least in part on the desired effect on the target site, the size of the target site, and/or local physiological conditions of the target site. In some embodiments, electrodes may be included on and/or in a treatment probe which may produce one of or both electrolysis and electroporation treatment. For example, the treatment probe may be used to execute the methods described above and/or illustrated inFIGS.2A-B. In some embodiments, the treatment probe may be used to implement an electrolysis device and/or an electroporation device, such as devices110,115illustrated inFIG.1. In some embodiments, the treatment probe may be a combination device used to implement both devices110,115. The treatment probe may be implemented using a needle, a wire, a disk, and/or combinations thereof. In some embodiments, the electrode or electrodes may include the entire treatment probe. In some embodiments, the electrode or electrodes may be included as a portion of the treatment probe. FIG.3is a schematic diagram of a treatment probe300according to an embodiment of the disclosure. The treatment probe300may incorporate both electroporation electrodes305and electrolysis electrodes310. The electrodes for electroporation305may be separate from the electrodes for electrolysis310. Having separate electrodes for each treatment modality may allow for independent optimization of the electrode configuration for both electroporation and electrolysis. For example, the electrode design for electrolysis may include materials that are selected for specific electrolysis product species production. In some embodiments, the electroporation electrodes305and the electrolysis electrodes310may be combined into electrodes that perform both electrolysis and electroporation. The electrode material for electroporation may be selected to avoid electrolysis product formation from the electrodes that may introduce metals in the body systemically. For example through the use of Titanium electrodes. The electrodes may be in any number, size and shape of electrodes using a separate electrode delivery approach. FIG.4is a schematic diagram of a treatment probe400according to an embodiment of the disclosure. In some embodiments, a treatment probe may integrate the electrodes405,410for electrolysis and electroporation. The electrodes for electrolysis, or certain ones of the electrodes, may be the same electrodes, or certain ones of the electrodes, that deliver electroporation. The electrodes may be in any number, size and shape using an integrated electrode approach. A number of different configurations may be used to integrate the delivery of electroporation and electrolysis into a catheter. The size, shape and configuration of the electrodes may be specifically tailored to the targeted treatment site. In some embodiments, a treatment probe may include a combination of electrodes used for both electrolysis and electroporation delivery. For example, an electrode may be used for both electroporation and electrolysis. A separate electrode may be used to complete the electroporation delivery and a separate electrode may be used to complete the electrolysis delivery. In some embodiments, the electrodes may be included on a plurality of treatment probes. For example, a first probe may include the electrolysis anode and a second probe may include the electrolysis cathode. The first and second probes may further include electroporation electrodes. Other examples of electrode combinations include, but are not limited to, two point electrodes, one point and one needle electrode, one point electrode and one pad electrode, two monopolar needle electrodes; one bipolar needle, one multipolar needle; two surface electrodes; one surface and one needle electrode, and/or combinations thereof. Other configurations of electrodes on one or more treatment probes may also be possible. The spacing between electrodes on the treatment probe and/or the spacing between treatment probes may also be adjusted to achieve a desired electrolysis and/or electroporation effect. FIGS.5A-Billustrate two examples of electrode configurations700A-B according to embodiments of the disclosure.FIG.5Aillustrates two needle electrodes705,710inserted in a tissue70.FIG.5Billustrates a point electrode720on an insulated shaft715inserted in a tissue70. A pad electrode725is placed remotely from the point electrode720. In some embodiments, the point electrode720may be an anode and the pad electrode725may be a cathode. The examples shown inFIG.5A-Bare for illustrative purposes only, and other electrode configurations are possible. The materials chosen for the electrodes, including the electrodes705,710, may be chosen to produce certain the electrolysis products. For example, an anode may include iridium oxide and/or rubidium oxide deposited on titanium, which may improve the production of hypochlorous acid, and a cathode may include copper. The use of mixed metal oxide anode electrodes may produce different species of electrolysis products that may be tailored for different clinical needs. For example, platinum may be used if inert electrodes are desired. Electroporation electrodes may include the same or different materials as electrolysis electrodes. In some embodiments, a solution may be injected in tissue to affect the process of electrolysis. For instance a solution of buffered physiological saline at a pH of between 2 and 5 may preferentially produce electrolysis products, such as hypochlorous acid. The apparatuses, devices, and systems, such as treatment probes, may all be used to deliver E2. Other configurations, apparatuses, devices, and/or systems for delivering E2 may also be used. For example, one or more needle electrodes may be used in combination with an ultrasound transducer configured to provide sonoporation. Imaging of E2 could also employ computed tomography (CT), magnetic resonance imaging (MRI) and electrical impedance tomography. E2 treatment may also be combined with cryotherapy, thermal therapy, chemical therapy, and/or combinations thereof. For example a cryosurgery probe may also serve as one of the electrolysis electrodes. Many clinical applications may benefit from the use of the combination of E2. The reduced energy requirement and reduce treatment times may overcome limitations that previously discouraged the use of either electroporation or electrolysis regardless of the benefits of each on a stand-alone basis. The combination of both may overcome the limitations and enable a multitude of clinical uses. The treatment of a variety of cancers by the combination of electroporation and electrolysis may be an enhanced treatment approach. The targeted treatment site may be accessed minimally invasively by either catheter or probe placement. The configuration of the device and the electrodes may deliver the combination of electroporation and electrolysis in an optimal manner for the targeted tumor. The types of tumors may include but are not limited to prostate, breast, lung, liver, brain, colon, esophagus, kidney, rectal, skin, stomach, pancreas, eye and uterine tumors. The combination of electroporation and electrolysis, E2, may be an effective clinical approach for both malignant and benign tumor treatments. Thus benign tumor sites like Benign Prostatic Hypertrophy, fibroids and myomas may be treated. The E2 protocol may also be used to selectively ablate small volumes of tissue in the body such as a lymph node or a cluster of lymph nodes. Another embodiment may utilize a method to control the dose the amount of electrolysis product produced and applied to the treatment site. A delivery device may be used to apply the electrolysis product produced at the time of application. Some specific experimental examples are provided below to facilitate appreciation of embodiments described herein. The experimental examples presented are not intended to be comprehensive or exhaustive of all experiments performed or of all results obtained. Example I According to a first non-limiting example, a Petri dish was used to cast an agar gel made of physiological saline with a pH dye. The pH dye was 5% pH indicator (RC Hagen wide range). The pH indicator was added to the agar gel phantom before its solidification. Two 0.9 mm graphite electrodes were inserted into the gel through a holder. Graphite was used to avoid contamination of the gel with metal ions. The electrodes were connected to a constant voltage power supply or to a BTX electroporation (Harvard Instruments) electroporator. The distance between the electrodes was 10 mm. Changes in color near the electrodes were observed due to electrolysis induced change in pH. The first experiment involved the delivery of typical electroporation pulses of 1000 V between the electrodes. One hundred microsecond long pulses at a frequency of 1 Hz in groups of 99 pulses were delivered. Between groups of pulses, a two minute rest period was used to let the system cool. The gel exhibited a stained region after 99 pulses. The stained region surrounded the electrodes and was not continuous, confirming the delivery of electrolysis products. However, the extent of the stain did not cover the treated tissue to the isoelectric field of 200 Vcm or 100 V/cm line, produced by the 1000 V electroporation pulses. In typical irreversible electroporation protocols used in current clinical applications, fewer than 100 pulses are used. Under these typical conditions there are no electrolysis products in the region of electric fields of 100 V/cm or 200 V/cm. 200 V/cm and 100 V/cm are reversible electroporation fields that do not cause cell death in the absence of electrolytic products. After three sequences of 99 pulses, a substantial volume of gel in the treated region has been affected by the products of electrolysis and has changed the pH of the gel. However, even after 3×99 pulses, the region affected by electrolysis has not yet reached the 100 V/cm isoelectric field line. The region affected by the anode was larger than that affected by the cathode. In addition, in the center of the region stained near the anode there was a white discolored circle. This may be due to a typical effect of electrolysis. In electrolysis there is an electro-osmotic driven flow of water from the anode to the cathode. This is a well-known phenomenon. This phenomenon may be used to generate flows in tissue during electrolysis in desirable directions. Furthermore, by adding electrolysis products by extending electrolysis treatment and/or introducing a solution configured for electrolysis product production, the treated zone may be substantially expanded. Example II According to a second non-limiting example, a Petri dish was used to cast an agar gel made of physiological saline with a pH dye. The pH dye was 5% pH indicator (RC Hagen wide range). The pH indicator was added to the agar gel phantom before its solidification. Two 0.9 mm graphite electrodes were inserted into the gel through a holder. Graphite was used to avoid contamination of the gel with metal ions. The electrodes were connected to a constant voltage power supply or to a BTX electroporation (Harvard Instruments) electroporator. The distance between the electrodes was 10 mm. Changes in color near the electrodes were observed due to electrolysis induced change in pH. The second experiment involved the delivery of typical electroporation pulses of 500 V between the electrodes. One hundred microsecond long pulses at a frequency of 1 Hz in groups of 99 pulses were delivered. Between groups of pulses, a two minute rest period was used to let the system cool. The pH affected area after three pulse sequences of 99 pulses and a voltage between electrodes of 500 V is smaller than when the pulse was of 1000 V. Example III According to a third non-limiting example, a Petri dish was used to cast an agar gel made of physiological saline with a pH dye. The pH dye was 5% pH indicator (RC Hagen wide range). The pH indicator was added to the agar gel phantom before its solidification. Two 0.9 mm graphite electrodes were inserted into the gel through a holder. Graphite was used to avoid contamination of the gel with metal ions. The electrodes were connected to a constant voltage power supply or to a BTX electroporation (Harvard Instruments) electroporator. The distance between the electrodes was 10 mm. The DC power supply applied a voltage of 10 V (a current of 60 mA) between the electrodes. It was evident that after 168 seconds the pH dye area marked as affected by electrolysis products from direct current was much larger than the area affected by electrolysis products generated by electroporation pulses in Examples I and II. The pH change affected area was sufficiently large so that a 1000 V pulse applied between the electrodes may ablate to the isoelectric field line of 100 V/cm. 100 V/cm is considered reversible electroporation and permeabilization of the cell membrane is typically done with eight pulses. Cells survive exposure to electric fields of eight, 100 V/cm. However, when electrolytic products are generated in sufficient quantity to diffuse to the 100 V/cm isoelectric-field lines, the cells exposed to eight 100 V/cm electric fields do not survive. Therefore, it appeared that a preferential way to use the combination of electrolysis/electroporation for tissue ablation is to use conventional electrolysis with relatively (compared to electroporation) long DC currents at low voltage and current for the products of electrolysis to diffuse through the targeted volume in combination with several high field electroporation type pulses that are sufficient to permeabilize the cell membrane. There may be several possible combination protocols with electrolysis type currents and electroporation type pulses delivered in various sequences and configurations. For instance: electrolysis first, electroporation later or electroporation first electrolysis later, or at different intervals in time between electrolysis and electroporation. Example IV According to a fourth non-limiting example, a Petri dish was used to cast an agar gel made of physiological saline with a pH dye. The pH dye was 5% pH indicator (RC Hagen wide range). The pH indicator was added to the agar gel phantom before its solidification. Two 0.9 mm graphite electrodes were inserted into the gel through a holder. Graphite was used to avoid contamination of the gel with metal ions. The electrodes were connected to a constant voltage power supply or to a BTX electroporation (Harvard Instruments) electroporator. The distance between the electrodes was 10 mm. A voltage of 5 V was applied across the electrodes with a current of 9 mA. Staining indicated that this produced a comparable outcome to electrolytic treatment with 10 V in Example III and is also suitable for tissue electrolysis/electroporation ablation protocol described in Example III. The center of the stained gel near the anode was discolored because of the water electromigration effect. Example V Conventional tissue ablation by electroporation is delivered using two electrodes, relatively close to each other to facilitate high electric fields with reasonable high voltages. It may be advantageous to ablate tissue by electroporation in a modality similar to radio-frequency thermal ablation, i.e. one electrode in the center of the undesirable tissue and a second electrode remotely. However, a problem with this configuration may be that for a single needle or point active electrodes with a remote second electrode, the electric field near the needle or point electrode descends very rapidly with distance from the electrode. In the case of the needle electrode, as one over the distance square and in the case of a point electrode, as one over the distance to the third power. According to a fifth, non-limiting example, a typical one dimensional in cylindrical coordinates needle electrode was used. The central electrode was 0.9 mm graphite and the second electrode was a lining of copper around the wall of a Petri dish. The Petri dish was used to cast an agar gel made of physiological saline with a pH dye. The pH dye was 5% pH indicator (RC Hagen wide range). The pH indicator was added to the agar gel phantom before its solidification. A sequence of electrolysis/electroporation treatment was applied with a single needle with 10 V and 200 mA. Two sets of experiments were performed, one set with the anode in the center and one set with the cathode in the center. The gel was observed after 45 seconds, 90 seconds, 120 seconds after start of electrolysis. Staining was observed around the electrode in both sets of experiments after 45 seconds, and the stained area continued to increase as time went on. The amount of electrolysis products observed in this set of experiments was significantly higher than for the case of two adjacent electrodes at the same voltage in the previous examples. The reason may be that the current was higher and/or possibly because the products from the anode and cathode do not interact with each other due to the increased distance. These experiments suggest that it may be advantageous to generate the electrolysis products from a central electrode with a distant second electrode. First the amount of electrolysis products appears to be higher and the composition appears to be better defined. It may be preferable when two electrodes are used for electroporation to use one or both of these electrodes with one polarity and another remote electrode with another polarity for generating electrolysis products in some applications. Second, this configuration of a central cylindrical or point electrode may take the most advantage of the combination of electrolysis and electroporation, because of the nature of the electric field distribution. Example VI According to a sixth non-limiting example, a typical one dimensional in cylindrical coordinates needle electrode was used. The central electrode was 0.9 mm graphite and the second electrode was a lining of copper around the wall of a Petri dish. The Petri dish was used to cast an agar gel made of physiological saline with a pH dye. The pH dye was 5% pH indicator (RC Hagen wide range). The pH indicator was added to the agar gel phantom before its solidification. Three sets of 1000 V, 100 microsecond long 1 Hz frequency, 99 pulses per set were delivered between the central electrode and the electrode around the Petri dish. It was observed that at a delivery time of 5 minutes with 1000 V electroporation type pulses, a negligible amount of electrolysis products relative to those produced by DC electrolysis in the previous examples. The isoelectric field lines typical of reversible electroporation were much closer to the central electrode than the isoelectric lines of 100 V/cm From the central electrode Examples V and VI, it is observed that combining electrolysis with electroporation may substantially expand the region of tissue ablation over electroporation alone. However, this may require that the extent of electrolytic effects be properly designed in relation to the extent of the electric fields generated. The various combinations of electrolysis and electroporation sequences discussed earlier may be valid here also. Example VII According to a seventh, non-limiting example, a standard electroporation system, ECM 830 electroporator, (BTX, San Diego, Calif.) with a typical electroporation 2 mm cuvette, 620 BTX was used. Specifically, 2 mm cuvettes were filled with pH buffered saline with an initial pH of 7.5 with cells, and applied electroporation protocols. Changes in pH were measured immediately after the delivery of the electroporation pulse sequences using an Oakton Instruments (PH 450) meter (Vermonth Hills, Ill.) with a micro-combination pH probe MI-414B (16 gauge, tip 6 cm length) (Bedford, N.H.) pH probe. The results are shown in the table inFIG.6. The pH data is the average pH from three repeats and the standard deviation. The pH was measured at the end of the electroporation field delivery protocol and represents the pH that would have existed when the cells were removed from the cuvettes for viability processing in. The table inFIG.6shows that the pH has changed in all the experiments and has become basic, which suggests the presence of electrolytic products. The difference in time of exposure to products of electrolysis during electroporation and the charge seem to correlate to cell viability. Example VIII According to an eighth, non-limiting example, pig liver tissue was ablated between two titanium electrodes 1.5 cm apart. In a first experiment, a first single exponential decay pulse was applied. The pulse had an initial voltage of 1230 V and a decay time constant of 2.4 ms. A square pulse was then applied for 10 minutes with a current of 200 mA. The square pulse was followed by a second exponential decay pulse having an initial voltage of 1160 V and a time constant of 2 ms. In a second experiment, an initial exponential decay pulse was applied with an initial voltage of 1260 V and a time constant of 2.6 ms. After the exponential decay pulse, a square pulse was applied for 5 minutes with a current of 100 mA. The square pulse was followed by a second exponential decay pulse having an initial voltage of 1210 V and a time constant of 2.2 ms. Both experiments demonstrated tissue ablation in the pig liver. Example IX According to a ninth, non-limiting example, pig liver tissue was ablated between two titanium electrodes 5 cm apart. A single exponential decay pulse was applied. The pulse had an initial voltage of 1040 V and a time constant of 2.2 ms. The experiment demonstrated complete tissue ablation in the pig liver between the electrodes. The examples provided are for explanatory purposes only and should not be considered to limit the scope of the disclosure. Those skilled in the art will recognize that the examples provided of both the design delivery systems and the clinical applications are not the limit of the uses of the combination of electroporation and electrolysis. Many configurations of delivery systems exist, as well as applications that would benefit from the use of the discovery we disclose. It is to be appreciated that any one of the above embodiments or processes may be combined with one or more other embodiments and/or processes or be separated and/or performed amongst separate devices or device portions in accordance with the present systems, devices and methods. Finally, the above-discussion is intended to be merely illustrative of the present devices, apparatuses, systems, and methods and should not be construed as limiting the appended claims to any particular embodiment or group of embodiments. Thus, while the present disclosure has been described in particular detail with reference to exemplary embodiments, it should also be appreciated that numerous modifications and alternative embodiments may be devised by those having ordinary skill in the art without departing from the broader and intended spirit and scope of the present disclosure as set forth in the claims that follow. Accordingly, the specification and drawings are to be regarded in an illustrative manner and are not intended to limit the scope of the appended claims.

11857245

DETAILED DESCRIPTION OF EMBODIMENTS Overview It may be challenging to perform multi-channel ablation on a subject. On the one hand, if the multiple ablation signals share a common frequency, it may be difficult to separately monitor and control each of the ablation signals, due to cross-talk between the channels. One possible solution is to modulate each of the ablation signals differently. However, such modulation may introduce parasitic frequencies that disturb nearby equipment, such as an electrocardiographic (ECG) monitor. On the other hand, assigning different respective frequencies to the ablation signals may also be problematic, due to the intermodulation distortion that may be introduced. To address this challenge, embodiments of the present invention use a common RF frequency (and phase) for all of the ablation signals, but add, to the ablation signals, different respective control signals having relatively small amplitudes. The control signals have different respective frequencies that are relatively close to the frequency of the ablation signals, and the amplitude of each control signal is a fixed fraction of the amplitude of the corresponding ablation signal. Due to these properties of the control signals, the ablation signals may be indirectly monitored by, and controlled responsively to, monitoring the control signals. At the same time, due to the relatively small amplitude of the control signals, relatively little intermodulation distortion is introduced. Advantageously, although each of the control-signal frequencies is close to the ablation-signal frequency, all of the frequencies are sufficiently different from each other such as to inhibit the generation of problematic parasitic frequencies. For example, the difference between any two of the frequencies may be greater than the bandwidth of a typical ECG signal, such that the smallest parasitic frequency that might be generated—which is generally equal to the smallest difference between any two of the frequencies—does not disturb the ECG recording. System Description Reference is initially made toFIG.1, which is a schematic illustration of a system20for multi-channel ablation, in accordance with some embodiments of the present invention. FIG. depicts a physician27performing a multi-channel cardiac ablation procedure on a subject25, using an ablation catheter23whose distal end36comprises a plurality of ablation electrodes44. To begin the procedure, physician27inserts catheter23into the subject, and then navigates the catheter, using a control handle32, to an appropriate site within, or external to, the heart30of subject25. Subsequently, the physician brings distal end36into contact with tissue33, such as myocardial or epicardial tissue, of heart30. Next, a signal-generating unit (SIG GEN)22generates a plurality of signals34, which are referred to herein as “composite signals” or “composite ablation signals,” as explained below with reference toFIG.2. Signals34are carried through catheter23, over different respective channels, to electrodes44, such that each electrode applies a different respective one of signals34to the tissue of the subject. Typically, the ablation is unipolar, in that signals34flow between electrodes44and an external electrode, or “return patch”51, that is coupled externally to the subject, typically to the subject's torso. System20further comprises a processor (PROC)24. Processor24is configured to receive from physician27(or any other user), prior to and/or during the ablation procedure, setup parameters38for the procedure. For example, using one or more suitable input devices such as a keyboard, mouse, or touch screen, the physician may input, for each ablation signal, a maximum power, a maximum current amplitude, a maximum voltage amplitude, a duration of the signal, and/or any other relevant parameters. (Typically, these parameters are the same across all of the signals.) In response to receiving setup parameters38, processor24communicates the setup parameters to signal-generating unit22, such that signal-generating unit22may generate signals34in accordance with the setup parameters. Additionally, the processor may display the setup parameters on a display26(which may comprise the aforementioned touch screen). Processor24may be further configured to track the respective positions of electrodes44during the procedure, using any suitable tracking technique. For example, distal end36may comprise one or more electromagnetic position sensors, which, in the presence of an external magnetic field generated by one or more magnetic-field generators42, output signals that vary with the positions of the sensors. Based on these signals, the processor may ascertain the positions of the electrodes. Alternatively, for each electrode, processor24may ascertain the respective impedances between the electrode and a plurality of external electrodes49coupled to subject25at various different locations, and then compute the ratios between these impedances, these ratios being indicative of the electrode's location. As yet another alternative, the processor may use both electromagnetic tracking and impedance-based tracking, as described, for example, in U.S. Pat. No. 8,456,182, whose disclosure is incorporated herein by reference. In some embodiments, the processor ascertains which of electrodes44are in contact with the subject's tissue, and causes those electrodes, but not the other electrodes, to deliver signals34to the tissue. In other words, the processor may select a subset of channels leading to those electrodes that are in contact with the tissue, and then cause signals34to be passed over the selected subset of channels, but not over the other channels. In some embodiments, the processor displays, on display26, a relevant image40of the subject's anatomy, annotated, for example, to show the current position and orientation of distal end36. Alternatively, or additionally, based on signals received from relevant sensors disposed at distal end36, the processor may track the temperature and/or impedance of tissue33, and control signal-generating unit22responsively thereto, as further described below with reference toFIG.2. Alternatively or additionally, the processor may perform any other relevant function for controlling, or otherwise facilitating the performance of, the procedure. Processor24, and signal-generating unit22, typically reside within a console28. Catheter23is connected to console28via an electrical interface35, such as a port or socket. Signals34are thus carried to distal end36via interface35. Similarly, signals for tracking the position of distal end36, and/or signals for tracking the temperature and/or impedance of the tissue, may be received by processor24via interface35. Typically, the functionality of processor24, as described herein, is implemented at least partly in software. For example, processor24may comprise a programmed digital computing device comprising at least a central processing unit (CPU) and random access memory (RAM). Program code, including software programs, and/or data are loaded into the RAM for execution and processing by the CPU. The program code and/or data may be downloaded to the processor in electronic form, over a network, for example. Alternatively or additionally, the program code and/or data may be provided and/or stored on non-transitory tangible media, such as magnetic, optical, or electronic memory. Such program code and/or data, when provided to the processor, produce a machine or special-purpose computer, configured to perform the tasks described herein. Notwithstanding the particular type of ablation procedure illustrated inFIG.1, it is noted that the embodiments described herein may be applied to any suitable type of multi-channel ablation procedure. Generating and Controlling the Composite Ablation Signals Reference is now made toFIG.2, which is a schematic illustration of signal-generating unit22, in accordance with some embodiments of the present invention. Signal-generating unit22comprises a plurality of signal generators46, configured to generate signals34, respectively, for application to subject25, as described above with reference toFIG.1. In other words, each signal generator46is configured to generate a different respective signal34to be passed through the tissue of the subject. Typically, each signal generator46comprises a control-signal generator50, configured to generate a control signal, an ablation-signal generator48, configured to generate an ablation signal, and a signal adder52, configured to produce signal34by adding the generated control signal to the generated ablation signal. By virtue of signal34being a combination of the control signal and the ablation signal, signal34is referred to herein as a “composite signal” or “composite ablation signal,” as noted above with reference toFIG.1. (It is noted that any “signal” described herein may alternatively be referred to as a “current,” such that, for example, signals34may be referred to as “composite ablation currents.”) While the control signals have different respective control-signal frequencies, the ablation signals typically have a single common ablation-signal frequency (and a single common phase). Alternatively, the ablation-signal frequencies may differ slightly from each other, such that, for example, the difference between the highest ablation-signal frequency and the lowest ablation-signal frequency is less than 500 Hz, which is the typical bandwidth of an ECG signal. In general, signal-generating unit22may comprise any suitable number of signal generators46, corresponding to the number of ablation electrodes44. For example, signal-generating unit22may comprise 2-20 signal generators46.FIG.2schematically illustrates “N” signal generators46, by showing both the first and Nthsignal generator. The first ablation-signal generator48is indicated by the notation “ABL_GEN_1,” while the Nthablation-signal generator48is indicated by the notation “ABL_GEN_N.” Similarly, the first control-signal generator50is indicated by the notation “CTRL_GEN_1,” while the Nthcontrol-signal generator50is indicated by the notation “CTRL_GEN_N.” In other embodiments, signal generators46comprise respective control-signal generators and signal adders, but do not comprise respective ablation-signal generators. Rather, signal-generating unit22comprises a single ablation-signal generator, which supplies an ablation signal to each signal adder. In the context of the present application, including the claims, such an ablation signal may be referred to as a “plurality of ablation signals,” given that the ablation signal is passed, over multiple lines, to multiple signal adders. Each ablation-signal generator48and control-signal generator50may comprise a digital-to-analog converter, a stable analog free-running generator, or a direct digital synthesizer (DDS), such as the AD9854 DDS by Analog Devices, Inc. of Norwood, Mass., USA. Typically, the smallest difference between any two of the control-signal frequencies is large enough such as to inhibit the generation of problematic parasitic frequencies. For example, this difference may be greater than 500 Hz, which is the typical bandwidth of an ECG signal. Similarly, the difference between the ablation-signal frequency and the closest control-signal frequency (i.e., the control-signal frequency that is closest to the ablation-signal frequency, relative to the other control-signal frequencies) is typically greater than 500 Hz. (For embodiments in which there are multiple ablation-signal frequencies, the smallest difference between any one of the ablation-signal frequencies and any one of the control-signal frequencies may be greater than 500 Hz.) Nevertheless, the control-signal frequencies are typically close enough to the ablation-signal frequency such that the control signals and ablation signals have similar frequency-related effects on the tissue of subject25. For example, the difference between any pair of successive frequencies may be between 500 and 1500 Hz. In other words, (i) the difference between the ablation-signal frequency and the closest control-signal frequency, and (ii) the difference between any pair of successive control-signal frequencies that are both greater than or both less than the ablation-signal frequency, may be between 500 and 1500 Hz. (Two given frequencies are said to be “successive” if, when all of the frequencies are listed in order of increasing or decreasing magnitude, the two given frequencies are listed sequentially.) Thus, for example, given a difference of 1 kHz, an ablation-signal frequency of 486 kHz, and N channels (assuming, for simplicity, that N is even), the control-signal frequencies may consist of 486−N/2 kHz, 486−N/2+1 kHz, . . . 485 kHz, 487 kHz, . . . 486+N/2-1 kHz, and 486+N/2 kHz. Each control-signal generator is configured to generate its control signal such that the ratio between the amplitude of the control signal and the amplitude of the ablation signal to which the control signal is added is constant (or “fixed”) during the application of the composite signal. As further described below, the constancy of this ratio may facilitate controlling the composite signal. Typically, the ratio is less than 1:15, such as less than 1:20, 1:40, 1:60, 1:80, 1:100, or 1:120, such that, by virtue of the relatively small amplitude of the control signal, relatively little intermodulation distortion is introduced. For example, if, following the amplification of the composite signal as described below, the ablation signal has an amplitude of 90-110 V, the control signal may have an amplitude of 1-2 V. Due to the frequency of the control signal being similar to that of the ablation signal, the two signals see a similar impedance across the tissue of the subject, such that the ratio between the voltages of the two signals is generally the same as the ratio between the currents of the two signals. Signal-generating unit22further comprises a plurality of controlled voltage dividers56, configured to adjust the respective amplitudes of the composite signals during the application of the composite signals to the subject. Typically, signal-generating unit22comprises one controlled voltage divider56for each signal generator46, such that the output from each signal adder52is passed to a different respective controlled voltage divider.FIG.2indicates the first controlled voltage divider by the notation “VD_1,” and the Nthcontrolled voltage divider by the notation “VD_N.” Each controlled voltage divider may comprise, for example, a digital potentiometer, such as the AD5122 digital potentiometer by Analog Devices. Typically, signal-generating unit22further comprises a plurality of amplifiers58, configured to amplify the adjusted signals received from the controlled voltage dividers. InFIG.2, the first amplifier58is indicated by the notation “AMP_1,” while the Nthamplifier is indicated by the notation “AMP_N.” The amplified signals are output to electrodes44, over a plurality of channels64. Signal-generating unit22further comprises one or more controllers54, configured to control the adjusting of the amplitudes by controlled voltage dividers56, in response to the respective currents of, and respective voltages of, the control signals, and based on the respective constant ratios between the control-signal amplitudes and ablation-signal amplitudes. Typically, signal-generating unit22comprises one controller54for each controlled voltage divider56(and for each signal generator46), such that the controlling output from each controller is passed to a different respective controlled voltage divider.FIG.2indicates the first controller by the notation “CTRL 1,” and the Nthcontroller by the notation “CTRL N.” Typically, each controller comprises an analog front-end, an analog-to-digital converter, a digital filter, and a processor. Some or all of these components may be included in a field-programmable gate array (FPGA), such as a Cyclone Family FPGA by Intel of Santa Clara, Calif., USA. Signal-generating unit22further comprises, for each channel64, circuitry, such as a voltage transformer60and a current transformer62, configured to step-down the voltage and current of signal34to measurable levels. The stepped-down voltage (e.g., the voltage induced across each voltage transformer60) and the stepped-down current (e.g., the current induced through each current transformer62) are input to the analog front-end of controller54, and are then converted, by the analog-to-digital converter, to digital signals. These signals are then filtered, by the digital filter, such that only the control-signal frequency remains. Subsequently, the controller (in particular, the processor of the controller) calculates the voltage and current of the control signal from the filtered signals. For example, the controller may measure the amplitudes of the filtered signals, and then multiply each of these amplitudes by the appropriate transformer ratio, such as to obtain the voltage and current of the control signal. Next, given the constant ratio between the control signal and the ablation signal, the controller may compute one or more properties of the ablation signal. For example, given a voltage amplitude VCTRLand a current amplitude ICTRLof the control signal, the controller may compute the voltage amplitude VABLand the current amplitude IABLof the ablation signal, by dividing each of VCTRLand ICTRLby R, the above-described ratio of the control-signal amplitude to the ablation signal amplitude. For example, if R=1:100, then VABL=100*VCTRL, and IABL=100*ICTRL. Subsequently, the controller may compute the power of the ablation signal from VABLand IABL. During the procedure, processor24continually communicates target parameters to signal-generating unit22, and in particular, to controllers54. These parameters may include setup parameters38, and/or parameters that are computed responsively to monitoring the subject during the procedure. The target parameters may be communicated directly from processor24, or via any suitable hardware or other circuitry not shown inFIG.2. The controller continually compares one or more measured or computed parameters of signal34to the target parameters, and, in response thereto, controls the adjusting of the amplitude of signal34by the controlled voltage dividers. For example, the processor may continually (i) monitor the temperature at the interface between distal end36and tissue33, (ii) responsively to this temperature, compute a target ablation-signal power, which does not exceed the maximum power specified by physician27, and (iii) communicate the target ablation-signal power to the controllers. Each controller may continually compare the received target power to the computed ablation-signal power, and, responsively to this comparison, cause the corresponding controlled voltage divider to increase or decrease the amplitude of signal34, such as to better match the target ablation-signal power. In some embodiments, the target parameters include a target power for the composite signals, alternatively or additionally to the aforementioned ablation-signal target power. (In other words, the target parameters may take into account the contribution of the control signals.) In such embodiments, each controller may compute the composite-signal voltage VCOMP, and the composite-signal current ICOMP, by multiplying each of VCTRLand ICTRLby (1+1/R). The controller may then compute the power of the composite signal from VCOMPand ICOMP, compare this power to the target, and then control the controller voltage divider responsively thereto. Typically, a single target power is specified for all of the channels. In some cases, however, different respective target powers may be specified for at least some of the channels. Alternatively or additionally to comparing the power of the ablation signal or of the composite signal to a target power, the controller may compare the current of the ablation signal or of the composite signal to a target current, and/or the voltage of the ablation signal or of the composite signal to a target voltage, and control the controller voltage divider responsively thereto. It is noted that, alternatively or additionally to the circuitry described above (such as the signal generators, controlled voltage dividers, and controllers), signal-generating unit22may comprise any other suitable circuitry, such as, for example, output transformers for impedance matching, passive bandpass and/or band-stop filters, or passive overvoltage protection devices. In some embodiments, each controller54continually calculates the impedance of tissue33from the measured voltages and currents, and communicates the calculated impedances to processor24. Typically, processor24displays these impedances on display26. Reference is now made toFIG.3, which is a flow diagram for a feedback control loop, in accordance with some embodiments of the present invention. As described above, each controller54effectively implements a feedback control loop, whereby, during the application of the relevant composite signal to the subject, the amplitude of the composite signal is controlled in response to the current and voltage of the control signal that is included in the composite signal. This control loop is more explicitly shown inFIG.3. First, prior to the beginning of the control loop, the controller is powered on, at a power-on step67. Subsequently, the controller receives, from processor24, a target ablation-signal power, at a target-receiving step69. Next, at an induced-signal-receiving step66, the controller receives the induced voltage and current signals from the voltage transformer and the current transformer, respectively. Next, at a digitizing-and-filtering step68, the controller digitizes the received signals, and then filters the digitized signals for the control-signal frequency, e.g., by applying a bandpass filter to the digitized signals. Subsequently, at a calculating step70, the controller calculates the voltage and current of the control signal from the filtered signals, as described above with reference toFIG.2. Next, at a first computing step72, the controller uses the fixed ratio between the ablation signal and the control signal to compute the voltage and current of the ablation signal. Subsequently, at a second computing step74, the controller computes the power of the ablation signal from the voltage and current of the ablation signal. The controller then compares the power of the ablation signal to the target power, at a comparing step76. If the power matches the target, the controller does not adjust the composite signal, but instead, returns to target-receiving step69. Otherwise, before returning to target-receiving step69, the controller causes the controlled voltage divider to adjust the amplitude of the composite signal, at an adjusting step78. It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of embodiments of the present invention includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof that are not in the prior art, which would occur to persons skilled in the art upon reading the foregoing description. Documents incorporated by reference in the present patent application are to be considered an integral part of the application except that to the extent any terms are defined in these incorporated documents in a manner that conflicts with the definitions made explicitly or implicitly in the present specification, only the definitions in the present specification should be considered.

11857246

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the surgical hand tool include two sections used together to perform a function. One or more of the sections can comprise segments, portions, components, or subcomponents. However, the use of the term “section” does not imply any particular structure or configuration. In some embodiments, the right section or components thereof are mirror image, identical, or substantially similar to the left section or components thereof. The sections or components thereof may be any suitable shape that permits the function of the hand tool, for instance perform the function of scissors and forceps. Certain embodiments are illustrated and/or described herein. With reference toFIGS.1-2A, a hand tool100is shown. The hand tool100can also be referred to as a surgical multi-tool. The hand tool100comprises two sections: a left section102and a right section202. In the illustrated configuration, the left section102includes multiple components and the right section202includes multiple components as described further below. The left section102interacts with the right section202to perform one or more functions, such as operating as forceps and scissors as described in detail below. The hand tool100has a longitudinal axis106that extends between a proximal end116and a distal end118. The left section102can be on the left side of the longitudinal axis106when the hand tool100is viewed from the top. The right section202can be on the right side of the longitudinal axis106when the hand tool100is viewed from the top. The surgical hand tool100can transition between functional configurations. As illustrated inFIGS.1and2A, the left section102can comprise a left handle132and a left tip160extending distally from the left handle132. The right section202can comprise a right handle232and a right tip260extending distally from the right handle232. The surgical hand tool can operate as forceps, which can also be referred to as the forceps configuration, with the left tip160and the right tip260providing the grasping ends of the forceps. In this and other configurations, the surgical hand tool100can also include electrodes. For example, the surgical hand tool ofFIGS.1and2Acan function as electrocautery bipolar forceps, as described further below. The surgical hand tool can further be configured to operate as scissors, which can also be referred to as the scissors configuration.FIG.4, described in more detail below, illustrates a scissors configuration where the tips160,260slide and pivot relative to each other to cut tissue. The scissors can be utilized to more quickly cut tissue. The multiple configurations allow for the use of multiple surgical techniques at the discretion of the user. Other functional configurations are possible. Referring now toFIGS.2A-4, the hand tool100is designed to transition between the forceps configuration and the scissors configuration. The forceps configuration is shown inFIG.2Aand the scissors configuration is shown inFIG.4. The intermediate configuration is shown inFIG.3. The hand tool100permits the switching between the forceps configuration and the scissors configuration. The hand tool100can transition between these configurations by rotation of the tips160,260of the hand tool100, as described further below. The tips160,260are rotated approximately 90 degrees between the forceps configuration shown inFIG.2Aand the scissors configuration shown inFIG.4. The tips can be brought together as shown inFIG.3during the transition between the forceps configuration and the scissors configuration. Components of the Hand Tool In some embodiments, the forceps configuration as shown inFIG.2Acan operate as bipolar electrocautery forceps. For instance, the hand tool100can include one or more electrodes located on the tips of the hand tool. The hand tool100can be designed to supply electrical energy to the electrodes. In some embodiments, the hand tool100can optionally include an electrical connection110. The electrical connection110can include a left lead112and a right lead212. The electrical connection110can enable the electrodes to be supplied with electrical energy. In the illustrated configuration, the electrical connection110can be near the proximal end116of the hand tool100. In some embodiments, the hand tool100can include a mechanical connector122. The mechanical connector122can function to electrically isolate the incoming electrical leads112,212. The mechanical connector122can function to couple the left section102and the right section202. The left lead112can include a receptacle114. The receptacle114can be sized to accept the left spring124. The left section102can include a left spring124that extends along the longitudinal axis106. The left spring124can be coupled to the mechanical connector122. In some embodiments, the left spring124can have an external shape that complements the shape of a receptacle126in the mechanical connector122. In the illustrated embodiment, the shape of the left spring124is rectangular and the shape of the receptacles126is rectangular. Other shapes are contemplated (e.g., wedge, oval, triangular, elliptical, polygonal, etc.). The left spring124can be coupled to the mechanical connector122by welding, fasteners, glue, friction fit, pawl and ratchet, detent and protrusion, or other fixation method. The left spring124can be coupled to the left lead112of the electrical connection110. In the illustrated embodiment, the left spring124is coupled to the left lead112within the mechanical connector122. The left spring124can be coupled to the left lead112by welding, fasteners or other fixation method. The left spring124can include a bend128. The bend128can function to extend the distal end of the left spring124away from the longitudinal axis106. The bend128can function to curve the left spring124outward from the mechanical connector122. The bend128of the left spring124can function to increase the distance between the left section102and the right section202. The left spring124can include a concave portion. The concave portion can be near the proximal end of the left spring124. The left spring124can include a convex portion. In the illustrated embodiment, the convex portion can be near the distal end of the left spring124. The left spring124can include one or more flat portions120,130. In the illustrated embodiment, the flat portion120can be disposed within the receptacle114. In other configurations the flat portion can be near the proximal end, distal end, or in between the proximal and distal end of the left spring124. Other configuration of the spring can be contemplated (e.g., multiple bends, flat portions, multiple layers, thicknesses, varying thickness, height and length, etc.). The distal end of the left spring124can be coupled to a left handle132. In some embodiments, the left spring124can have an external shape that complements the shape of a receptacle134in the left handle132. In the illustrated embodiment, the flat portion130can be disposed within the receptacle134. In the illustrated embodiment, the shape of the left spring124is rectangular and the shape of the receptacle134is rectangular. Other configurations are contemplated (e.g., wedge, oval, triangular, elliptical, polygonal, etc.). The left spring124can be coupled to the left handle132by welding, fasteners, glue, friction fit, pawl and ratchet, detent and protrusion, or other fixation method. In the illustrated embodiment, the receptacle134is a slot that extends from the top of the left handle132to the bottom of the left handle132, or a portion thereof. In some embodiments, the left spring124can be adjustable within the receptacle134of the left handle132. In some embodiments, the left spring124can be adjusted to a number of discrete positions with the receptacle134(e.g., two, three, four, five, etc.). In some embodiments, the left spring124can be adjusted to an infinite number of positions with the receptacle134. The left spring124can remain movable, releasably retained or fixedly retained in position. The left handle132can include one or more finger grips136(seeFIG.9A). In the illustrated embodiment, two finger grips136are shown. Other numbers of finger grips are contemplated (e.g., one, two, three, four, five, etc.). Both of the finger grips136are shown on the exterior surface of the left handle132. Other locations are possible (e.g., top surface, bottom surface, interior surface, at least one grip on the exterior surface, at least one grip on the top surface, a grip on the top surface and a grip on the exterior surface, etc.). The left handle132can have a bayonet configuration. The left handle132can include a longitudinally extending portion138and a vertically extending portion140. The longitudinally extending portion138can extend generally along the longitudinal axis106. The vertically extending portion140can extend upward from the longitudinally extending portion138. The vertically extending portion140can improve the line of sight for the user. The user's hand can engage the longitudinally extending portion138. The vertically extending portion140can raise the distal end118of the hand tool100away from the user's hand. The user's hand does not obstruct the line of sight to the distal end118of the hand tool100. In the illustrated embodiment, the vertically extending portion140forms an angle142with the longitudinally extending portion138. The angle142can be 90° or greater than 90° (e.g., 100°, 110°, 120°, 130°, 140°, 150°, 160°, 170°, etc.). The angle142can be obtuse. Other configurations are possible. The angle142can provide a more ergonomic grip to the user. The left section102can include a left hub144. The left hub144can extend from the vertically extending portion140. In some embodiments, the left hub144can be a unitary structure with the vertically extending portion140of the left handle132. The left hub144and the left handle132can be monolithically formed. In other embodiments, the left hub144is a separate component from the left handle132. The vertically extending portion140can include a recess146. The left hub144can be coupled to the recess146by welding, fasteners, glue, friction fit, pawl and ratchet, detent and protrusion, or other fixation method. In some embodiments, the left hub144is removable from the vertically extending portion140. For instance, the left hub144can be removed to permit sterilization of the left tip160. The left hub144can be removed to replace the left tip160. The left hub144can include a proximal portion148. The proximal portion148of the left hub144can be received within the recess146of the vertically extending portion140. The recess146can be shaped to complement the external surface of the proximal portion148. The proximal portion148can be any cross-sectional shape including semi-circular, triangular, rectangular, etc. In some embodiments, the proximal portion148can extend the entire length of the vertically extending portion140. The edge150of the proximal portion148can be angled to match the angle142. The left hub144can include a distal portion152. The distal portion152can extend from the vertically extending portion140. The distal portion152can extend from the recess162when proximal portion148is received within the recess162. The edge154of the distal portion152can include a hub recess156. The distal portion152can be a portion of a cylinder. The distal portion152can be any cross-sectional shape including semi-circular. In some embodiments, the proximal portion148and the distal portion152have the same cross-sectional shape. In other embodiments, the proximal portion148and the distal portion152have different cross-sectional shapes. In some embodiments, the proximal portion148and the distal portion152can have the same diameter. In other embodiments, the proximal portion148and the distal portion152have different diameters. The left hub144can define a left tip axis158. The left tip axis158can be the axis upon which the left tip160rotates. The distal portion152of the left hub144can function to support the left tip160during rotation. The hub recess156can be aligned with the left tip axis158. The hub recess156can function to maintain alignment of the left tip160during rotation. In some methods of assembly, the left hub144is coupled to the vertically extending portion140. This can create a channel between the external surface of the left hub144and the internal surface of the recess162. A portion of the left tip160can rotate within this channel. The left tip160can include a proximal portion164. The proximal portion164of the left tip160can be supported by the left hub144. The proximal portion164of the left tip160can rotate about the left hub144. At least a portion of the proximal portion164of the left tip160can be received within the recess162of the vertically extending portion140. In the illustrated embodiment, the recess162of the vertically extending portion140can include a first portion166and a second portion168. The first portion166can have a circular cross-section and the second portion168can have a circular cross-section. The first portion166can have a semi-circular cross-section and the second portion168can have a semi-circular cross-section. The cross-sectional shapes of the first portion166and the second portion168can permit rotation of the left tip160within the recess162. The first portion166can have a first diameter and the second portion168can have a second diameter. The first diameter can be smaller than the second diameter. The first portion166can be located distal to the second portion168. The first portion166of the recess162can be closer to the distal end118. The second portion168can be located proximal to the first portion166. The second portion168of the recess162can be closer to the proximal end116. The difference in diameter between the first portion166and the second portion168of the recess162can create a lip. The recess162can have any number of portions (e.g., two, three, four, five, six, etc.). Each portion can have a diameter that is either the same or different than one or more other portions. At least two of the portions have unequal diameters. Of the at least two portions, a portion near the distal end can have a smaller diameter than another portion near the proximal end. The difference in diameter between the portions of the recess162can create a lip. In the illustrated embodiment, the left tip160can include a ridge174which can interact with the lip. The ridge174can extend from the external surface of the proximal portion164of the left tip160. The ridge174can be sized to be received within the second portion168of the recess162. For instance, the ridge174and the second portion168can have the same or similar diameter. The ridge174can have a larger diameter than the first portion166. The ridge174can abut the lip created by the first portion166and the second portion168. The ridge174can reduce axial translation of the left tip160when the left tip160is received within the recess162. The ridge174can reduce the longitudinal movement of the left tip160when the ridge174is received within the recess162. The ridge174can prevent disengagement between the vertically extending portion140and the left tip160by the application of axial force. The proximal portion164of left tip160can include a left extension178which can interact with the hub144. The left extension178can be a portion of a cylinder. In some embodiments, the left extension178can have a quarter-circular cross-section (e.g., encompasses 90 degrees). The left extension178can have a convex external surface. The convex external surface can be complementary to the second portion168. The left extension178can have a concave internal surface180. The concave internal surface180can be complementary to the external surface of the distal portion152of the left hub144. The proximal portion164of left tip160can include a protrusion172which can interact with the hub recess156. The protrusion172is sized to be received within the hub recess156. For instance, the protrusion172and the hub recess156can have the same or similar diameter. The protrusion172can extend along the left tip axis158when the ridge174is received within the recess162. The protrusion172and the hub recess156can provide a pivot for the left tip160as the left tip160rotates. The left tip160can include a distal portion170. The distal portion170of the left tip160can include a longitudinally extending portion182. The longitudinally extending portion182can be a portion of a cylinder. In some embodiments, the longitudinally extending portion182can have a semi-circular cross-section (e.g., encompasses 180 degrees). The longitudinally extending portion182can have a convex external surface. The distal170and longitudinally extending182portions can have other cross-sectional shapes (e.g., circular, elliptical, square, rectangular, triangular, polygonal, sigmoid, etc.). The distal portion170of the left tip160can include a conical portion186. The conical portion186can extend to a distal tip188. The conical portion186and distal tip188can interact with the right section202to function as forceps. The conical portion186can include a cutting edge190. The cutting edge190can interact with the right section202to function as scissors. The cutting edge190can be the same material as the distal portion170of the left tip160. The cutting edge190can be the same material as the left tip160. The cutting edge190can be a different material than the distal portion170of the left tip160. The cutting edge190can be a different material than the left tip160. The cutting edge190can be integrally or monolithically formed with the left tip160. The cutting edge190can be a separate component and coupled to the left tip160. The distal portion170of the left tip160can have a flat internal surface184. The flat internal surface184can be complementary to an internal surface of the right section202. The flat internal surface184can extend the length of the longitudinally extending portion182. The flat internal surface184can extend the length of the conical portion186. The flat internal surface184can abut a flat internal surface of the right tip. Other cross-sectional shapes of the internal surface can be contemplated (e.g., circular, elliptical, square, rectangular, triangular, polygonal, sigmoid etc.). These can be complimentary, mirror or rotationally similar to the right tip260. The distal portion170of the left tip160can include an electrode192. In some embodiments, the longitudinally extending portion182can include the electrode192. In some embodiments, the conical portion186can include the electrode192. In some embodiments, the distal tip188can include the electrode192. In some embodiments, the flat internal surface184can include the electrode192. In some embodiments, the external surface of the left tip160can include the electrode192. The electrode192can interact with the right section202. The right section202can include a ground or another electrode. The left tip160can interact with the right section to function as an electrosurgical device. The electrode192can be activated by electrical energy supplied to the hand tool100. The electrode192can be activated when the hand tool100is in the forceps configuration. In some embodiments, electrical energy is prevented from being supplied when the hand tool100is in the scissors configuration. The electrode192can be the same material as the distal portion170of the left tip160. The electrode192can be the same material as the left tip160. The electrode192can be a different material than the distal portion170of the left tip160. The electrode192can be a different material than the left tip160. The electrode192can be integrally or monolithically formed with the left tip160. The electrode192can be a separate component and coupled to the left tip160. In some embodiments, the left lead112can pass through a channel in the left spring124. The left lead112can pass through a channel in the left handle132. The left lead112can pass through a channel in the left tip160. The channels in any of the components in the left section102can be insulated. In some methods of assembly, the left tip160is inserted within the recess162. Then the left hub144is coupled to the vertically extending portion140. The left tip160is place in the recess prior to coupling of the left hub144. The left tip160can be retained within the recess162by a retention mechanism (not shown). In some embodiments, the left hub144is removable. The left hub144can be removed to replace the left tip160. The left hub144can be removed to sterilize or replace the left tip160. In some embodiments, the left hub144is integrally formed with the vertically extending portion140. Then the left tip160is inserted within the recess162. The ridge174is aligned with the second portion168the recess162in the vertically extending portion140. The internal surface180of the left extension178is aligned with the external surface of the left hub144. The protrusion172of the left tip160is aligned with the hub recess146. From this position, the left tip160can be rotated about the left tip axis158. The left tip160can be rotated until the ridge174is received within the second portion168of the recess162. In this position, the internal surface180of the left extension178can be in contact with the external surface of the left hub144. In this position, protrusion172can be received within the hub recess146. In some embodiments, the left section102and the right section202each form of a symmetrical, opposed half. The right section202can be a mirror image of the left section102. The right section202can include substantially similar or identical components. In some embodiments, the right section202may have a different shape or configuration to enhance ergonomics for the user. The right lead212can include a receptacle214. The receptacle214can be sized to accept the right spring224. The right section202can include a right spring224that extends along the longitudinal axis106. The right spring224can be coupled to the mechanical connector122. In some embodiments, the right spring224can have an external shape that complements the shape of a receptacle226in the mechanical connector122. In the illustrated embodiment, the shape of the right spring224is rectangular and the shape of the receptacles226is rectangular. Other configurations are contemplated (e.g., wedge, oval, triangular, elliptical, polygonal, etc.). The right spring224can be coupled to the mechanical connector122by welding, fasteners, glue, friction fit, pawl and ratchet, detent and protrusion, or other fixation method. The right spring224can be coupled to the right lead212of the electrical connection110. In the illustrated embodiment, the right spring224is coupled to the right lead212within the mechanical connector122. The right spring224can be coupled to the right lead212by welding, fasteners or other fixation method. The right spring224can include a bend228. The bend228can function to extend the distal end of the right spring224away from the longitudinal axis106. The bend228can function to curve the right spring224outward from the mechanical connector122. The bend228of the right spring224can function to increase the distance between the left section102and the right section202. The right spring224can include a concave portion. The concave portion can be near the proximal end of the right spring224. The right spring224can include a convex portion. In the illustrated embodiment, the convex portion can be near the distal end of the right spring224. The right spring224can include one or more flat portions220,230. In the illustrated embodiment the flat portion220can be disposed within the receptacle214. In other configurations the flat portion can be near the proximal end, distal end, or in between the proximal and distal end of the right spring224. The right spring224can provide the same or different resistance as the left spring124. The right spring224can provide the same or different shape as the left spring124. The right spring224can be a mirror image of the left spring124. The distal end of the right spring224can be coupled to a right handle232. In some embodiments, the right spring224can have an external shape that complements the shape of a receptacle234in the right handle232. In the illustrated embodiment the flat portion230can be disposed within the receptacle234. In the illustrated embodiment, the shape of the right spring224is rectangular and the shape of the receptacle234is rectangular. Other configurations are contemplated (e.g., wedge, oval, triangular, elliptical, polygonal, etc.). In the illustrated embodiment, the receptacle234is a slot that extends from the top of the right handle232to the bottom of the right handle232, or a portion thereof. In some embodiments, the right spring224is coupled to the right handle232by welding, fasteners, glue, friction fit, pawl and ratchet, detent and protrusion, or other fixation method. In some embodiments, the right spring224is adjustable within the receptacle234of the right handle232. In some embodiments, the right spring224can be adjusted to a number of discrete positions with the receptacle234(e.g., two, three, four, five, etc.). In some embodiments, the right spring224can be adjusted to an infinite number of positions with the receptacle234. The right spring224can remain movable, releasably retained or fixedly retained in position. In some embodiments, the right spring224is movable and the left spring124is fixed. At least one spring124,224can be movable to accommodate the user's hand. In some embodiments, both springs124,224are movable to accommodate the user's hand. The right handle232can include one or more finger grips236. In the illustrated embodiment, two finger grips236are shown but other configurations are contemplated (e.g., one, two, three, four, five, etc.). Both of the finger grips236are shown on the exterior surface of the right handle232. Other locations are possible (e.g., top surface, bottom surface, interior surface, at least one grip on the exterior surface, at least one grip on the top surface, a grip on the top surface and a grip on the exterior surface, etc.). The finger grips236can have the same or different configuration as the finger grips136. For instance, one set of finger grips can be shaped for the index finger and the other set of grips can be shaped for the thumb. The finger grips136,236can be positioned based on the manner in which the user is expected to hold the hand tool100. The finger grips136,236can be positioned based on right handed use. The finger grips136,236can be positioned based on left handed use. The finger grips136,236can be positioned based on ambidextrous use. The right handle232can have a bayonet configuration. The right handle232can include a longitudinally extending portion238and a vertically extending portion240. The longitudinally extending portion238can extend generally along the longitudinal axis106. The vertically extending portion240can extend upward from the longitudinally extending portion238. The vertically extending portion240can improve the line of sight for the user. The user's hand can engage the longitudinally extending portion238. The vertically extending portion240can raise the distal end118of the hand tool100away from the user's hand. The user's hand does not obstruct the line of sight to the distal end118of the hand tool100. In the illustrated embodiment, the vertically extending portion240forms an angle242with the longitudinally extending portion238. The angle242can be 90° or greater than 90° (e.g., 100°, 110°, 120°, 130°, 140°, 150°, 160°, 170°, etc.). The angle242can be obtuse. The angle242can be the same as angle142. In other embodiments, the angle242is different than angle142based on the manner in which the user is expected to hold the hand tool100. The angle242can be selected to better complement the grip of the user (e.g., based on the anatomy of the human hand). Other configurations are possible. The right section202can include a right hub244. The right hub244can extend from the vertically extending portion240. In some embodiments, the right hub244can be a unitary structure with the vertically extending portion240of the right handle234. The right hub244and the right handle232can be monolithically formed. In other embodiments, the right hub244is a separate component from the right handle232. The vertically extending portion240can include a recess246. The right hub244can be coupled to the recess246by welding, fasteners, glue, friction fit, pawl and ratchet, detent and protrusion, or other fixation method. In some embodiments, the right hub244is removable from the vertically extending portion240. For instance, the right hub244can be removed to permit sterilization of the right tip260. The right hub244can be removed to replace the right tip260. The right hub244can include a proximal portion248. The proximal portion248of the right hub244can be received within the recess246of the vertically extending portion240. The recess246can be shaped to complement the external surface of the right hub244. The proximal portion248of the right hub244can be any cross-sectional shape including semi-circular, triangular, rectangular, etc. In some embodiments, the proximal portion248can extend the entire length of the vertically extending portion240. The edge250of the proximal portion248can be angled to match the angle242. The right hub244can include a distal portion252. The distal portion252can extend from the vertically extending portion240. The distal portion252can extend from the recess262when proximal portion248is received within the recess262. The edge254of the distal portion252can include a hub recess256. The distal portion252can be a portion of a cylinder. The distal portion252can be any cross-sectional shape including semi-circular. In some embodiments, the distal portion248and the distal portion252have the same cross-sectional shape. In other embodiments, the proximal portion248and the distal portion252have different cross-sectional shapes. In some embodiments, the proximal portion248and the distal portion252can have the same diameter. In other embodiments, the proximal portion248and the distal portion252have different diameters. The right hub244can define a right tip axis258. The right tip axis258can be the axis upon which the right tip260rotates. The distal portion252of the right hub244can function to support the right tip260during rotation. The hub recess256can be aligned with the right tip axis258. The hub recess256can function to maintain alignment of the right tip260during rotation. In some methods of assembly, the right hub244is coupled to the vertically extending portion240. This can create a channel between the external surface of the right tip260and the internal surface of the recess262. A portion of the right tip260can rotate within this channel. The right tip260can include a proximal portion264. The proximal portion264of the right tip260can be supported by the right hub244. The proximal portion264of the right tip260can rotate about the right hub244. At least a portion of the proximal portion264of the right tip260can be received within the recess262of the vertically extending portion240. In the illustrated embodiment, the recess262of the vertically extending portion240can include a first portion266and a second portion268(not shown). The first portion266can be similar or a mirror image of first portion166. The second portion268can be similar or a mirror image of second portion168. The first portion266can have a circular cross-section and the second portion268can have a circular cross-section. The first portion266can have a semi-circular cross-section and the second portion268can have a semi-circular cross-section. The cross-sectional shapes of the first portion266and the second portion268can permit free rotation of the right tip260within the recess262. The first portion266can have a first diameter and the second portion268can have a second diameter. The first diameter can be smaller than the second diameter. The first portion266can be located distal to the second portion268. The first portion266of the recess262can be closer to the distal end118. The second portion268can be located proximal to the first portion266. The second portion268of the recess262can be closer to the proximal end116. The difference in diameter between the first portion266and the second portion268of the recess262can create a lip. The recess262can have any number of portions (e.g., two, three, four, five, six, etc.). Each portion can have a diameter that is either the same or different than one or more other portions. At least two of the portions have unequal diameters. Of the at least two portions, a portion near the distal end can have a smaller diameter than another portion near the proximal end. The difference in diameter between the portions of the recess262can create a lip. In the illustrated embodiment, the right tip260can include a ridge274which can interact with the lip. The ridge274can extend from the external surface of the proximal portion264of the right tip260. The ridge274can be sized to be received within the second portion268of the recess262. For instance, the ridge274and the second portion268can have the same or similar diameter. The ridge274can have a larger diameter than the first portion266. The ridge274can abut the lip created by the first portion266and the second portion268. The ridge274can reduce axial translation of the right tip260when the right tip260is received within the recess262. The ridge274can reduce the longitudinal movement of the right tip260when the ridge274is received within the recess262. The ridge274can prevent disengagement between the vertically extending portion240and the right tip260by the application of axial force. The proximal portion164of right tip260can include a right extension278which can interact with the hub244. The right extension278can be a portion of a cylinder. In some embodiments, the right extension278can have a quarter-circular cross-section (e.g., encompasses 90 degrees). The right extension278can have a convex external surface. The convex external surface can be complementary to the second portion268. The right extension278can have a concave internal surface280. The concave internal surface280can be complementary to the external surface of the distal portion252of the right hub244. The proximal portion264of right tip260can include a protrusion272which can interact with the hub recess256. The protrusion272is sized to be received within the hub recess256. For instance, the protrusion272and the hub recess256can have the same or similar diameter. The protrusion272can extend along the right tip axis258when the ridge274is received within the recess262. The protrusion272and the hub recess256can provide a pivot for the right tip260as the right tip260rotates. The right tip260can include a distal portion270. The distal portion270of the right tip260can include a longitudinally extending portion282. The longitudinally extending portion282can be a portion of a cylinder. In some embodiments, the longitudinally extending portion182can have a semi-circular cross-section (e.g., encompasses 180 degrees). The longitudinally extending portion282can have a convex external surface. The distal270and longitudinally extending282portions can have other cross-sectional shapes (e.g., circular, elliptical, square, rectangular, triangular, polygonal, sigmoid, etc.). The distal portion270of the right tip260can include a conical portion286. The conical portion286can extend to a distal tip288. The distal tip288can interact with the left section102to function as forceps. The conical portion286can include a cutting edge290. The cutting edge290can interact with the left section102to function as scissors. The cutting edge290can be the same material as the distal portion270of the right tip260. The cutting edge290can be the same material as the right tip260. The cutting edge290can be a different material than the distal portion270of the right tip260. The cutting edge290can be a different material than the right tip260. The cutting edge290can be integrally or monolithically formed with the right tip260. The cutting edge290can be a separate component and coupled to the right tip260. The distal portion270of the right tip260can have a flat internal surface284. The flat internal surface284can be complementary to an internal surface of the left section102. The flat internal surface284can extend the length of the longitudinally extending portion282. The flat internal surface284can extend the length of the conical portion286. The flat internal surface284can abut a flat internal surface of the left tip160. Other cross-sectional shapes of the internal surface can be contemplated (e.g., circular, elliptical, square, rectangular, triangular, polygonal, sigmoid, etc.). These can be complimentary, mirror or rotationally similar to the right tip160. The distal portion270of the right tip260can include an electrode292. In some embodiments, the longitudinally extending portion282can include the electrode292. In some embodiments, the conical portion286can include the electrode292. In some embodiments, the distal tip288can include the electrode292. In some embodiments, the flat internal surface284can include the electrode292. In some embodiments, the external surface of the right tip260can include the electrode292. The electrode292can interact with the left section102. The left section102can include a ground or another electrode. The right tip260can interact with the left section102function as an electrosurgical device. The electrode292can be activated by electrical energy supplied to the hand tool100. The electrode292can be activated when the hand tool100is in the forceps configuration. In some embodiments, electrical energy is prevented from being supplied when the hand tool100is in the scissors configuration. The electrode292can be the same material as the distal portion270of the right tip260. The electrode292can be the same material as the right tip260. The electrode292can be a different material than the distal portion270of the right tip260. The electrode292can be a different material than the right tip260. The electrode292can be integrally or monolithically formed with the right tip260. The electrode292can be a separate component and coupled to the right tip260. In some embodiments, the right lead212can pass through a channel in the right spring224. The right lead212can pass through a channel in the right handle232. The right lead212can pass through a channel in the right tip260. The channels in any of the components in the right section202can be insulated. In some methods of assembly, the right tip260is inserted within the recess262. Then the right hub244is coupled to the vertically extending portion240. The right tip260is place in the recess262prior to coupling of the right hub244. The right tip260can be retained within the recess262by a retention mechanism (not shown). In some embodiments, the right hub244is removable. The right hub244can be removed to replace the right tip260. The right hub244can be removed to sterilize the right tip260. In some methods of assembly, the right hub244is coupled to the vertically extending portion240. This creates a channel between the external surface of the right hub244and the internal surface of the recess262. In some embodiments, the right hub244is integrally formed with the vertically extending portion240. Then the right tip260is inserted within the recess262. The ridge274is aligned with the second portion268the recess262in the vertically extending portion240. The internal surface280of the right extension278is aligned with the external surface of the right hub244. The protrusion272of the right tip260is aligned with the hub recess246. From this position, the right tip260can be rotated about the right tip axis258. The right tip260can be rotated until the ridge274is received within the second portion268of the recess162. In this position, the internal surface280of the right extension278can be in contact with the external surface of the right hub244. In this position, the protrusion272can be received within the hub recess256. As shown inFIG.1, the hand tool100can include a pin296coupled to a portion of the right tip260. The pin296can be positioned on the right extension278. The pin296can extend from an external surface of the right extension278. The pin296can extend radially outward from the outer surface of the right extension278. In the illustrated embodiment, the pin296extends at an angle to the right tip axis158. The angle may be substantially perpendicular or perpendicular. The pin296can extend transverse to the right tip axis258. The pin296can be a separate component coupled to the right tip260. The pin296can be coupled by welding, fasteners, glue, friction fit, pawl and ratchet, detent and protrusion, or other fixation method. The pin296can be integrally or monolithically formed with the right tip260. The pin296can interact with a mechanism300, as discussed in greater detail below. In an alternative embodiment, a pin can be coupled to a portion of the left tip160rather than the right tip260. The pin can be a mirror image of the pin296. The pin can be positioned on the left extension178. The pin can extend from an external surface of the left extension178. The pin can extend radially outward from the outer surface of the left extension178. The pin296can be positioned on either extension178,278. The pin296can be positioned on either tip160,260. In some embodiments, one of the tips160,260can have a protrusion294and the other tip can have a recess194. Referring toFIGS.2B,7C, and8C, the left tip160can have the recess194and the right tip260can have the protrusion294. In other embodiments, the left tip160can have the protrusion294and the right tip260can have the recess194. The protrusion294can extend perpendicularly from the flat internal surface284of the right tip260. The protrusion294can be located near the longitudinally extending portion282or the conical portion286of the right tip260. The recess194can extend perpendicularly from the flat internal surface184of the left tip160. The recess194can be located near the longitudinally extending portion182or the conical portion186of the left tip160. The protrusion294and the recess194can be located near the distal end118of the hand tool100. The protrusion294can be sized to fit within the recess194. The protrusion294or the recess194can include features to facilitate insertion of the protrusion294within the recess194. In some embodiments, the edges of the protrusion294are rounded to facilitate insertion. The protrusion294can provide a pivot for the tips160,260to rotate relative to each other. The protrusion294and the recess194can provide an axis198upon which the tips160,260can pivot relative to each other. The protrusion294can engage the recess194when the hand tool100is in the scissor configuration. The protrusion294can engage the recess194when the hand tool100is in the intermediate configuration. Each tip160,260can include a cutting edge190,290. The cutting edges190,290can be located on the conical portions186,286. The cutting edges190,290can be located on the longitudinally extending portions182,282. Each tip160,260can include one cutting edge, similar to a pair of scissors. The cutting edges190,290can have a range of motion from a closed position to an open position. In some embodiments, the angle formed between the cutting edges190,290is ninety degrees in the open position. When the cutting edges190,290are being closed, the cutting edges190,290can shear relative to each other. This action can cut tissue. In some embodiments, each tip160,260can include two or more cutting edges. The springs124,224can be designed to return each handle132,232to a neutral position. In some embodiments, the neutral position can include a separation between the conical portions186,286. In some embodiments, the neutral position can include a separation between the longitudinally extending portions182,282. In some embodiments, the neutral position can include a separation between the handles132,232. In other configurations, the hand tool100can include one spring (e.g., either the left spring124or the right spring224). For instance, the hand tool100can include the right spring224. The longitudinally extending portion128of the left handle132can extend to the mechanical connector122. The right handle232can be manipulated to move the right tip260relative to the left tip160. In some embodiments, the longitudinally extending portions128,228are curved or substantially curved (e.g., concave, convex, bent, etc.). In other configurations, the longitudinally extending portions128,228are straight or substantially straight. In some embodiments, the conical portions186,286are curved or substantially curved (e.g., concave, convex, bent, etc.). In other configurations, the conical portions186,286are straight or substantially straight. In some embodiments, the handles132,232of the hand tool100can extend substantially along the longitudinal axis106. The recesses162,262can extend along the longitudinal axis106. The handles132,232can have any cross-sectional shape including rectangular, square, polygonal, etc. In some embodiments, the handles132,232are straight or substantially straight. In some embodiments, the handles132,232are curved or substantially curved (e.g., concave, convex, bent, etc.). In some embodiments, electrical energy is supplied at a location along the length of the hand tool100. For instance, electrical energy can be supplied to each handle132,232of hand tool100. The lead112can be coupled to the left handle132and the lead212can be coupled to the right handle232. The distance between the handles132,232can function as an electrical isolator. For instance, electrical energy can be supplied to each hub144,244of hand tool100. The lead112can be coupled to the left hub144and the lead212can be coupled to the right hub244. The distance between the hubs144,244can function as an electrical isolator. For instance, electrical energy can be supplied to each tip160,260of hand tool100. The lead112can be coupled to the left tip160and the lead212can be coupled to the right tip260. The distance between the tips160,260can function as an electrical isolator. Each tip160,260can include electrode192,292for bipolar electrocautery. The electrodes192,292can be located on the longitudinally extending portion182,282. The electrodes192,292can be located on the conical portion186,286. The electrodes192,292can be located on an external surface of the tips160,260. The electrodes192,292can be located on an internal surface of the tips160,260for instance the flat surfaces184,284. The electrodes192,292can be configured for cauterization, hemostasis, and tissue dissection. The hand tool100can allow current to flow from the location where electrical energy is supplied to the electrodes192,292. The hand tool100can have a current passage that allows current to flow through the hand tool100and to the electrodes192,292. The hand tool100can be sufficiently insulated to prevent the dissipation of electrical energy. The hand tool100can be grounded. The hand tool100can be designed to operate in conjunction with currently available current generators. The hand tool100can have a fluid passage having a fluid inlet and a fluid outlet. The fluid inlet can be located near a proximal end116of the hand tool100. The fluid inlet can be connectable to a fluid source. The fluid outlet can be located near the distal end118of the hand tool100. In some embodiments, the hand tool100can have more than one fluid outlet. The fluid outlet can be in fluid communication with the fluid inlet, such that fluid can travel through the fluid passage of the hand tool100. The fluid outlet can be located on the longitudinally extending portion182,282. The fluid outlet can be located on the conical portion186,286. The fluid outlet can be located on an external surface of the tips160,260. The fluid outlet can be located on an internal surface of the tips160,260, for instance the flat surfaces184,284. The fluid outlet can be located near the electrodes192,292. The fluid can be a coolant, a medication, or any substance selected to be delivered to the surgical site. The hand tool100can be designed to operate in conjunction with currently available fluid systems. Operation of the Hand Tool The hand tool100can transition between at least two functional configurations, as shown generally inFIGS.2A and4. These configurations are referred to as the forceps configuration and the scissors configuration. In some embodiments, the forceps configuration includes a bipolar electrocautery forceps configuration. In some embodiments, the scissors configuration includes a microscissors configuration. In some embodiments, the scissors configuration and the forceps configuration are mutually exclusive functional configurations. FIG.2Ashows the hand tool100in the forceps configuration. The springs124,224bias the handles132,232away from each other. The distal tips188,288can be separated in the neutral position. The user can apply a force to the handles132,232to move the distal tips188,288toward each other. The user can release the force to the handles132,232and the distal tips188,288can return to the neutral position. FIG.3shows the hand tool100in the intermediate configuration. In order to change configurations, the handles132,232are moved toward each other. The user applies a force to overcome the biasing force of the springs124,224. The internal surface of the handles132,232can abut. The left tip160and the right tip260can be brought together. The tips160,260can abut. The internal flat surfaces184,284can abut. The left tip axis158and the right tip axis258can align along the longitudinal axis106. The protrusion294can engage the recess194. The intermediate configuration permits the transition from the forceps configuration to the scissors configuration. The intermediate configuration permits the transition from the scissors configuration to the forceps configuration. FIG.4shows the hand tool100in the scissors configuration. The springs124,224bias the handles132,232away from each other. The distal tips188,288can be separated in the neutral position. The user can apply a force to the handles132,232to move the distal tips188,288toward each other. The user can apply a force to the handles132,232to pivot the distal tips188,288about the axis198. The user can apply a force to the handles132,232to shear the cutting edges190,290past each other. The user can release the force to the handles132,232and the distal tips188,288can return to the neutral position. In both the forceps and the scissors configuration, the proximal portion164of the left tip160is retained within the recess162. In both the forceps and the scissors configuration, the proximal portion264of the right tip260is retained within the recess262. In both the forceps and the scissors configuration, the ridge174is retained within the recess162. In both the forceps and the scissors configuration, the ridge274is retained within the recess262. In the forceps configuration, the internal flat surfaces184,284are vertical or substantially vertical. In the scissors configuration, the internal flat surfaces184,284are horizontal or substantially horizontal. In the forceps configuration, the right tip260can be horizontally offset from the left tip160. The right tip260can be toward the right and the left tip160can be toward the left. In the scissors configuration, the right tip260can be generally over top the left tip160. In the scissors configuration, the left tip160can be generally underneath the right tip260. As shown inFIGS.1-4, the hand tool100can include a mechanism300that enables the user to transition between the forceps configuration and the scissors configuration. In the illustrated embodiment, the mechanism300is located on the right handle232. The mechanism300can interact with the pin296. The mechanism300can be located as part of the same section as the pin296. In the illustrated embodiment, the pin296is located on the right section202. In the illustrated embodiment, the mechanism300is located on the right section202. The mechanism300can include a slide302. The slide302can be coupled to the vertically extending portion240. In the illustrated embodiment, the vertically extending portion140can include a retaining hole298. The slide302can include a guide slot310. The guide slot310can engage the retaining hole298. For instance, the retaining hole270can engage a screw (not shown). The screw can translate within the guide slot310when the slide302translates. In some embodiments, the slide302can be coupled via a rail, protrusion, detent, ratchet, etc. The slide302is designed to translate along a portion of the vertically extending portion240. The slide302is capable of sliding upward and downward relative to the right handle232. The slide302can be less than the total height of the vertically extending portion240or a percentage of the total height (e.g., 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, etc.). The slide302can be less than the total width of the vertically extending portion240or a percentage of the total width (e.g., 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, etc.). The slide302can be greater than the total width of the vertically extending portion240(e.g., 110%, 120%, 130%, 140%, 150%, 160%, 170%, 180%, 190%, 200%, 300% etc.). The slide302can include a lower portion304and an upper portion306. The lower portion304can be approximately the same length as the vertically extending portion240. The upper portion306can be a greater length than the vertically extending portion240. The upper portion306can extend distally from the vertically extending portion240near the upper edge of the slide302. In some embodiments, the upper portion306can include a housing308. The housing308can extend distally from the vertically extending portion240near the upper edge of the slide302. The housing308can have a greater width than the width of the lower portion304. The housing308can be convex. The housing308can have a non-symmetrical shape. In the illustrated embodiment, the slide302can include at least a portion that extends distally from the vertically extending portion240. The housing308can include any shape (e.g., circular, elliptical, square, rectangular, triangular, polygonal, sigmoid, etc.). The mechanism300can include a grip312. The grip312can be located near an edge of the slide302. The grip312can be located proximally from the vertically extending portion240. In the illustrated embodiment, the grip312is located near the proximal end of the slide302. Other configurations are contemplated (e.g., near the top of the slide302, near the bottom of the slide302, on an external surface of the slide302, etc.). The grip312can include one or more ridges to facilitate the movement of the slide302. Other configurations are contemplated (e.g., roughened surfaces, protrusions, etc.). The mechanism300can include a slot314. The slot314provides a path for the pin296as the slide302is translated. The slot314can be within the housing308. The outer perimeter of the slot314can be within or smaller than the outer perimeter of the housing308. The housing308can have a width sufficient to enclose the pin296. The housing308can have an area of increased thickness near the slot314. The increased thickness can facilitate repeated movements against the pin296without deformation of the housing308. In some embodiments, the slot314is covered. The slot314can be covered by an external surface of the housing308. In other embodiments, the slot314is exposed to the user. In some embodiments, the slot314is linear. In other embodiments, the slot314is non-linear. The slot314can have a variety of shapes including curved, s-shaped, bow-tie shaped, sloped, stepped, etc. The slot314can have any shape that allows the slot314to function as a guide for the pin296. The slot314can be integrally formed with the slide302. The slot314can be formed by any machining, casting or forming processes. The slot314can function to guide the pin296. The pin296, as discussed above, is coupled to the right tip260. In the illustrated embodiment, the pin296extends from an external surface of the right extension278. An edge of the slot314pushes the pin296as the slide302is moved. The shape of the slot314permits the pin to rotate about the right tip axis258as the slide302is moved. In some embodiments, the pin296can be adjusted to a number of discrete positions within the slot314(e.g., two, three, four, five, etc.). In some embodiments, the pin296can be adjusted to an infinite number of positions within the slot314. The slide302can be coupled to the hand tool100at two points of contact. The slide302can be coupled to the vertically extending portion140with the retaining hole298and the guide310. The slide302can be coupled to the tip260with the pin296and the slot314. As the slide302translates, the screw (not shown) in the retaining hole298translates within the guide310. As the slide302translates, the pin296translates within the slot314. The mechanism300can have a first position and a second position. The first position can correspond to forceps configuration. The second position can correspond to the scissor configuration. In the illustrated embodiments, the mechanism300can be in the first position when the slide302is lower on the vertically extending portion240. There can be a larger separation between the top surface of the slide302and the top surface of the vertically extending portion240. There can be a smaller separation between the bottom surface of the slide302and the bottom surface of the vertically extending portion240. The bottom surface of the slide302and the bottom surface of the vertically extending portion240can be aligned.FIG.2Ashows the mechanism300in the first position. When the mechanism300is in the first position, the left tip160and the right tip260can be used as forceps. In the illustrated embodiments, the mechanism300can be in the second position when the slide302is higher on the vertically extending portion240. There can be a smaller separation between the top surface of the slide302and the top surface of the vertically extending portion240. The top surface of the slide302and the top surface of the vertically extending portion240can be aligned. There can be a larger separation between the bottom surface of the slide302and the bottom surface of the vertically extending portion240.FIG.4shows the mechanism300in the second position. When the mechanism300is in the second position, the left tip160and the right tip260can be used as scissors. FIGS.5A and5Bshow the mechanism300in the first position.FIG.5Ashows the front view of the hand tool100andFIG.5Bshows a cross-section view along line B-B. In the first position, the pin296is near the lower end of the slot314. The pin296is retained within the slot314. In the illustrated embodiment, the pin296is not being acted on by any edge of the slot314. FIGS.6A and6Bshow the mechanism300in the second position.FIG.6Ashows the front view of the hand tool100andFIG.6Bshows a cross-section view along line M-M. In the second position, the pin296is near the upper end of the slot314. As the slide302is moved upward along the vertically extending portion240, an edge of the slot314can come into contact with the pin296. Further upward movement of the slide302can cause the edge of the slot314to exert a force on the pin296. This force can cause the pin296to rotate about the right tip axis258. Further upward movement of the slide302can cause the pin to rotate a quarter turn (e.g., 90°) or approximately a quarter turn (e.g., 80°, 85°, 90°, 95°, 100°, etc.). Rotation of the pin296can cause the right tip260to rotate within the recess262of the vertically extending portion240. Rotation of the right tip260can exert a force on the left tip160. The force exerted by the right tip260can be directly exerted on the left tip160. As the right tip260is rotated within the recess262, the left tip160can rotate within the recess162. FIGS.7A-7Cshow the mechanism300in the first position.FIG.7Ashows the side view of the hand tool100.FIG.7Bshows a cross-section view along line D-D.FIG.7Cshows a cross-section view along line G-G. In the illustrated embodiment, the first position corresponds to the slide302being in a lower position as shown inFIG.7A. The pin296can extend from the right extension278as shown inFIG.7B. The pin296can be retained within the slot314. In the illustrated embodiment, the slot314is formed in a portion of the housing308. The pin296can have a sufficient size to extend past the vertically extending portion240and into the housing308. The pin296can have a greater dimension than the width of the vertically extending portion240. The pin296can be positioned at an angle202. The angle202can be approximately 45° from the vertical plane of the hand tool100. Other angles are possible (e.g., 0°, 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, 90°, etc.). The protrusion294can be received in the recess194as shown inFIG.7C. FIGS.8A-8Cshow the mechanism300in the second position.FIG.8Ashows the side view of the hand tool100.FIG.8Bshows a cross-section view along line P-P.FIG.8Cshows a cross-section view along line T-T. In the illustrated embodiment, the second position corresponds to the slide302being in a higher position as shown inFIG.8A. The pin296can be rotated as shown inFIG.8B. The pin296can be positioned at an angle204. The angle204can be approximately 45° from the vertical plane of the hand tool100. Other angles are possible (e.g., 0°, 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, 90°, etc.) The pin296can rotate approximately 90° as the mechanism300is moved from the first position to the second position. The pin296can rotate approximately 90° as the hand tool100is transitioned between the forceps configuration and the scissors configuration. Other ranges of motion of the pin296are possible (e.g., 80°, 85°, 90°, 95°, 100°). The protrusion294can be received in the recess194as shown inFIG.8C. The protrusion294can extend from the internal flat surface284of the right tip260. The recess194can extend into the internal flat surface184of the left tip160. The tips160,260can rotate or pivot about the protrusion294. The tips160,260can rotate or pivot about the axis198. The protrusion294can extend downward such that gravity aids in the retention of the protrusion294within the recess194. The functional configuration of the hand tool100is selected by the user by manipulating the mechanism300. The user can slide a finger to move the slide312. The user can manipulate the mechanism300while holding the hand tool100. The slide312can change the position of the slot314relative to the pin296. The mechanism300can exert a force on the pin296to rotate the pin296. In the illustrated embodiment, an edge of the slot314of the mechanism300can act on the pin296. The rotation of the pin296can rotate both tips160,260. The tips160,260can rotate approximately 90° as the hand tool100is transitioned between the forceps configuration and the scissors configuration. Other ranges of motion of the tips160,260are possible (e.g., 80°, 85°, 90°, 95°, 100°). The mechanism300can convert translational motion of the slide312into rotational motion of pin296. When the slide312is moved upward, the mechanism300can apply a rotational force to the pin296. The pin296can be coupled to the right extension278. The right extension278can have a cross-sectional shape of roughly a quarter-circle. The right extension278can rotate within the recess262of the vertically extending portion240as the pin296is rotated. The right extension278can rotate about the right hub244as the pin296is rotated. The right hub244can provide support to the right tip260as the pin296is rotated. The protrusion272and the hub recess256can maintain alignment of the right tip260as the right tip260is rotated. The right tip260can rotate about the right tip axis258. The right tip260can rotate about the longitudinal axis106. The left extension178can have a cross-sectional shape of roughly a quarter-circle. The left extension178can rotate within the recess162of the vertically extending portion140as the pin296is rotated. The left extension178can rotate about the left hub144as the pin296is rotated. The left hub144can provide support to the left tip260as the pin296is rotated. The protrusion172and the hub recess156can maintain alignment of the left tip160as the left tip160is rotated. The left tip160can rotate about the left tip axis158. The left tip160can rotate about the longitudinal axis106. Both tips160,260can rotate the same direction. In the illustrated embodiment, the right tip260rotates clockwise along the right hub244when the hand tool100transitions from the forceps configuration to the scissors configuration. The right tip260rotates counter-clockwise along the right hub244when the hand tool100transitions from the scissors configuration to the forceps configuration. In the illustrated embodiment, the left tip160rotates clockwise along the left hub144when the hand tool100transitions from the forceps configuration to the scissors configuration. The left tip160rotates counter-clockwise along the left hub144when the hand tool100transitions from the scissors configuration to the forceps configuration. The rotation in the clockwise direction is shown inFIGS.7B and8B. Other configurations are possible, where the mechanism rotates the tips clockwise to embody the transitions from the scissors configuration to the forceps configuration and counterclockwise to transitions from the forceps configuration to the scissors configuration. In some embodiments, one mechanism300is provided. In the illustrated embodiment, the mechanism300is coupled to the right handle232and the pin296is provided on the right tip260. The right tip260is the leader and the left tip160is the follower. The tips160,260can be brought together and into contact in the intermediate configuration. In the intermediate configuration, movement of the right tip260can impart a force on the left tip160to cause rotation. In some embodiments, the mechanism300is coupled to the left handle132and the pin296is provided on the left tip160. The left tip160can be the leader and the right tip260can be the follower. In some embodiments, more than one mechanism300is provided. One mechanism300is coupled to the right handle232and the pin296is provided on the right tip260. Another mechanism is coupled to the left handle132and another pin is provided on the left tip160. The user can move one or both mechanisms300to rotate the tips160,260. The user selects the configuration of the hand tool100by movement of the mechanism300. In some embodiments, the mechanism300is moved by a finger of the hand in which the hand tool100is held. In some embodiments, the mechanism300is moved by the thumb of the hand in which the hand tool100is held. In some embodiments, the mechanism300is moved by a finger or thumb of the hand not holding the hand tool100. The mechanism300allows the user to select between functional configurations with relative ease. The movement of the mechanism300can be intuitive to the user. The hand tool100does not need to be removed from the surgical site to switch configurations. The mechanism300can be manipulated while the tips160,260remain within the surgical site. The hand tool100requires the user to collapse the hand tool100in the intermediate configuration. This requires less space than either the forceps configuration or the scissors configuration. Once in the intermediate configuration, the user can transition between the forceps configuration and the scissors configuration. The hand tool100does not require any large movements to switch configurations. Once the hand tool100is in the desired configuration, the scissors or forceps are operated conventionally. In the forceps configuration, movement of the handles132,232causes the forceps to come together. The springs124,224can return the handles132,232to a neutral position. In the scissors configuration, movement of the handles132,232causes the cutting edges of the tips160,260to shear with respect to each other. The springs124,224return the handles132,232to a neutral position. Component to Facilitate Scissor Function The hand tool100can include a component to maintain alignment of the tips160,260in the scissors configuration. This component can ensure engagement between the cutting edges190,290to allow the tips160,260to cut tissue. In the illustrated embodiment, the component is a sleeve400. The sleeve400can extend along the length of one of the tips160,260in the forceps configuration. The sleeve400can extend along the length of both tips160,260in the scissors configuration. Other mechanisms are contemplated which function to hold the tips160,260together in the scissors configuration. FIGS.9A-9Dshow an embodiment of the sleeve400.FIG.9Ashows the perspective view of the hand tool100with the sleeve400.FIG.9Bshows a top view andFIG.9Cshows a side view.FIG.9Dshows a cross-section view along line K-K. InFIG.9A, the right handle232is removed. The sleeve400is coupled to the left handle132. The sleeve400can be coupled to the left handle132by welding, fasteners, glue, friction fit, pawl and ratchet, detent and protrusion, or other fixation method. In the illustrated embodiment, the sleeve400is coupled to the vertically extending portion140. The sleeve400extends from the vertically extending portion140. The sleeve400extends along the left tip axis158. The sleeve400can include a proximal portion402near the vertically extending portion140. The proximal portion402can be flat or substantially flat. The proximal portion402can be offset from the left tip160. In some embodiments, the proximal portion402is not in contact with the left tip160. The sleeve400can include a distal portion404. The distal portion404can have an internal surface406and an external surface408. The internal surface406can be concave. The internal surface406can be sized to complement the external shape of the left tip160. The diameter of the internal surface406can be equal or approximately equal to the diameter of the left tip160. The diameter of the internal surface406can be slightly larger than the diameter of the external surface of the left tip160or a percentage thereof (e.g., 105%, 110%, 115%, 120%, 125%, 130%, 140%, 145%, 150%, etc.). The internal surface406can complement the external shape of the left tip160in the forceps configuration. The internal surface406can also complement the external shape of a portion of the left tip160and a portion of the right tip260in the scissors configuration. The external surface408of the distal portion404can be convex. The external surface408can have any shape (e.g., elliptical, oval, rectangular, square, etc.). The sleeve400can include a middle portion410that transitions between the proximal portion402and the distal portion404. The sleeve400can be tapered as shown inFIG.9B. The proximal portion402can surround a smaller portion of the left tip160. The distal portion404can surround a larger portion of the left tip160. The sleeve400can extend along a portion of the tip160. In the illustrated embodiment, the conical portion186extends distally from the sleeve400as shown inFIG.9C. The sleeve400is sized to permit movement of the tips160,260in the forceps configuration and the scissors configuration. In the forceps configuration (not shown), the distal portion404surrounds the left tip160. The internal surface406can be adjacent to the left tip106. The internal surface406can be in contact with or abut the left tip106. The distal portion404can surround the entire left tip160or a portion thereof. The distal portion404can extend beyond the left tip160. In the illustrated embodiment, the distal portion404can be semi-circular. The left tip160can be semi-circular. In the scissors configuration shown inFIG.9D, the distal portion404surrounds a portion of the left tip160and a portion of the right tip260. The internal surface406can be adjacent to a portion of the left tip160and a portion of the right tip260. The internal surface406can be in contact with or abut a portion of the left tip160and a portion of the right tip260. The distal portion404can surround a percentage of the left tip160(e.g., 30%, 40%, 50%, 60%, 70%, etc.). The distal portion404can surround a percentage of the right tip260(e.g., 30%, 40%, 50%, 60%, 70%, etc.). The distal portion404can surround half of the left tip160and half of the right tip260. In the illustrated embodiment, the internal surface406can be semi-circular. The external surface of the left tip160and the right tip260can be semi-circular. The internal surface406allow the free rotation of the left tip160and the right tip260there within. The internal surface406can take other shapes or combination of shapes (e.g., semi-circular and flat, rectangular, circular, elliptical, square, rectangular, triangular, polygonal, sigmoid, etc.). FIG.9Dshows the sleeve400contacting both tips160,260in the scissors configuration. The sleeve400can function to hold the tips160,260together in the scissors configuration. The sleeve400can function to prevent separation of the tips160,260in the scissors configuration. The sleeve400can function to prevent separation of the protrusion294and the recess194in the scissors configuration. The movement of the right tip260upward is reduced or prevented by the sleeve400. The movement of the left tip160downward is reduced or prevented by the sleeve400. Other mechanisms are contemplated which function to hold the tips160,260together in the scissors configuration. Locking Component to Maintain Functional Configuration The hand tool100can include a locking mechanism500. The locking mechanism500can function to reduce or prevent rotational movement of one or more of the extensions178,278. The locking mechanism500can function to reduce or prevent rotational movement of one or more of the tips160,260. The locking mechanism500can be locked when the hand tool100is in the forceps configuration, as shown inFIG.2A. The locking mechanism500can be locked when the hand tool100is in the scissors configuration, as shown inFIG.4. The locking mechanism500can be unlocked when the hand tool100is in the intermediate configuration, as shown inFIG.3. FIGS.10A-10Cshow an embodiment of the locking mechanism500. The locking mechanism500can include a bar502. The bar502can be any shape (e.g., straight, curved, bent, s-shape etc.). In the illustrated embodiment, the bar502has a bend. The bar502can be retained within a slot. The bar502can move within the slot in a direction perpendicular or substantially perpendicular to the right tip axis258. In the illustrated embodiment, the slot can be located in the right hub244. The slot can be located in the proximal portion248or the distal portion252of the right hub244. In the illustrated embodiment, the slot can be located in the proximal portion248. In some embodiments, the slot is within the right handle232. The bar502can be coupled to a pin504. The pin504can be any shape (e.g., curved, straight, u-shaped, slanted, etc.). In the illustrated embodiment, the pin504is u-shaped. The pin504can include a proximal end which engages the bar502. The pin504can include a distal end which engages the extension278. In the illustrated embodiment, the pin504can engage a recess in the extension278. In the illustrated embodiment, the pin504has two prongs. The upper prong of the pin504can engage the recess when the hand tool100is in the scissors configuration, as shown inFIGS.10A-10C. The lower prong of the pin504can engage the recess when the hand tool100is in the forceps configuration. The pin504can prevent rotation of the extension278when a prong of the pin504engages the recess of the extension278. The bar502can extend from an internal surface of the handle232. The action of abutting the handles132,232can cause the bar502to move within the slot. This action can unlock the locking mechanism500. The locking mechanism500can be unlocked when the handles132,232are brought toward each other. In some embodiments, the left handle132will exert a force on the bar502. In some embodiments, the hub144will exert a force on the bar502. The bar502can move outward from the longitudinal axis106. The bar502can move toward the handle232. The shape of the bar502can cause the pin504to be moved along the right tip axis258. The pin504can translate toward the proximal end116as the bar502is moved toward the handle232. The pin504can disengage the recess of the extension278when the pin504translates proximally. The upper prong of the pin504can disengage the recess when the pin504translates proximally. The lower prong of the pin504can disengage the recess when the pin504translates proximally. The tips160,260can be rotated when the pin504disengages the recess in the right extension278. The locking mechanism500can have a neutral position. The neutral position can be the locked position. In the neutral position, a prong of the pin504can engage the recess in the extension278. The locking mechanism500can return to the neutral position via a spring. In other embodiments, the locking mechanism500can be returned to the neutral position by other means (e.g., magnets, gravity, manually force, etc.). The locking mechanism500can be manually moved by the user. The locking mechanism500can be returned to the neutral position by the action of separating the handles132,232. In some embodiments, the locking mechanism500is placed within the recess262in the vertically extending portion240. The locking mechanism500would block the rotational movement of the right extension278in the recess262. In some embodiments, the locking mechanism500is placed within the recess162in the vertically extending portion140. The locking mechanism500would block the rotational movement of the left extension178in the recess162. In some embodiments, the locking mechanism500can remain in one recess162,262. In some embodiments, a locking mechanism500can be provided for each recess162,262. In some embodiments, the locking mechanism500can move between the recesses162,262. For instance, the locking mechanism500can be located in the recess262when the hand tool100is in the forceps configuration. The locking mechanism500can rotate into the recess162when the hand tool100is in the scissors configuration. In the illustrated embodiment, the locking mechanism500can be included in the right section202. In some embodiments, the locking mechanism500can be included in the left section102. In some embodiments, the locking mechanism500can be included in both the left section102and the right section202. Other embodiments are contemplated to prevent the extensions178,278from rotating (e.g., spring, detent, magnet, etc.). In other embodiments, the user can manipulate an interface (not shown) to unlock the locking mechanism500. The neutral position can be that the locking mechanism500is locked. For instance, the interface (not shown) can be a button that when depressed would unlock the locking mechanism500. The interface (not shown) can be a slide that can have a position when the locking mechanism500is locked and a position when the locking mechanism500is unlocked. Other configurations of interfaces (not shown) are contemplated. The hand tool100can be generally composed of metal alloys, plastic, or other suitable biocompatible material. The hand tool100can be made by conventional machining and metal fabrication techniques, plastic fabrication techniques, and finishing processes including but not limited to milling, lathing, electrodischarge and welding, injection molding, powder coating and painting. The hand tool100can be optionally coated with one or more coatings, including but not limited to plastic, rubber, powder coat and paint or any combination thereof. The hand tool100can comprise multiple parts assembled and delivered to its intended user. The hand tool100can be sterilized before it is provided to the intended user. Different methods of switching configurations, different mechanism for rotating the tips, different configurations of the pin are contemplated. Further, the hand tool100may be configured to provide different tool functions than forceps and scissors described herein. Further, the hand tool100may have additional functional configurations corresponding to different tools. The hand tool100may be used in conjunction with other tools, for instance an operating microscope. Other embodiments of the hand tool are shown in U.S. Provisional Patent Application No. 61/906,337 filed Nov. 19, 2013, the disclosures of which is incorporated by reference herein in its entirety. The hand tool100described herein can have any of the features, components, or subcomponents described in the provisional application. In the illustrated embodiment ofFIGS.1-9in the provisional application, the handle132can include an additional longitudinally extending portion located distal of the vertically extending portions140,240. This additional longitudinally extending portion is shown in FIGS. 1-3 of U.S. Provisional Patent Application No. 61/906,337. The additional longitudinally extending portion of the left handle132can include the recess162. The recess162can be enclosed or partially enclosed by the additional longitudinally extending portion. The recess162can be semi-circular as described herein. The recess162can be sized to receive the left extension178. In some embodiments, the right handle232can be a mirror image of the left handle132. The right handle232can include an additional longitudinally extending portion. The additional longitudinally extending portion can include the recess262. The recess262can be enclosed or partially enclosed by the additional longitudinally extending portion. The recess262can be semi-circular as describe herein. The recess262can be sized to receive the right extension278. The tips160,260can include a respective longitudinally extending portion182,282, as shown in FIG. 5 of U.S. Provisional Patent Application No. 61/906,337. The longitudinally extending portion182,282can be semi-circular. The tips160,260can include a respective conical portion186,286. The tips160,260can include a respective extension178,278. The extensions178,278can be quarter-circular. At least one of the extensions178,278can include an engaging surface. The engaging surface can be a pin. The pin can extend parallel or substantially parallel to the tip axis158,258. The engaging surface can be rotated to the extensions178,278within the recesses162,262. The engaging surface can be rotated to transition the hand tool between a forceps configuration and a scissors configuration. The mechanism300can include a slide302as shown in FIG. 6 of U.S. Provisional Patent Application No. 61/906,337. The slide312can include a slot314configured to interact with the pin. The slide is configured to move upward and downward. The movement of the slide can rotate the engaging surface. The engaging surface can rotate the extension178,278to which the engaging surface is attached. The extension can rotate one of the tips160,260which can impart a force of the other of the tips160,260. Although this disclosure has been described in the context of certain embodiments and examples, it will be understood by those skilled in the art that the disclosure extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses and obvious modifications and equivalents thereof. In addition, while several variations of the embodiments of the disclosure have been shown and described in detail, other modifications, which are within the scope of this disclosure, will be readily apparent to those of skill in the art. It is also contemplated that various combinations or sub-combinations of the specific features and aspects of the embodiments may be made and still fall within the scope of the disclosure. For example, features described above in connection with one embodiment can be used with a different embodiment described herein and the combination still fall within the scope of the disclosure. It should be understood that various features and aspects of the disclosed embodiments can be combined with, or substituted for, one another in order to form varying modes of the embodiments of the disclosure. Thus, it is intended that the scope of the disclosure herein should not be limited by the particular embodiments described above.

11857247

The drawings are not intended to be limiting in any way, and it is contemplated that various embodiments of the technology may be carried out in a variety of other ways, including those not necessarily depicted in the drawings. The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present technology, and together with the description explain the principles of the technology; it being understood, however, that this technology is not limited to the precise arrangements shown. DETAILED DESCRIPTION The following description of certain examples of the technology should not be used to limit its scope. Other examples, features, aspects, embodiments, and advantages of the technology will become apparent to those skilled in the art from the following description, which is by way of illustration, one of the best modes contemplated for carrying out the technology. As will be realized, the technology described herein is capable of other different and obvious aspects, all without departing from the technology. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not restrictive. It is further understood that any one or more of the teachings, expressions, embodiments, examples, etc. described herein may be combined with any one or more of the other teachings, expressions, embodiments, examples, etc. that are described herein. The following-described teachings, expressions, embodiments, examples, etc. should therefore not be viewed in isolation relative to each other. Various suitable ways in which the teachings herein may be combined will be readily apparent to those of ordinary skill in the art in view of the teachings herein. Such modifications and variations are intended to be included within the scope of the claims. For clarity of disclosure, the terms “proximal” and “distal” are defined herein relative to a surgeon or other operator grasping a surgical instrument having a distal surgical end effector. The term “proximal” refers the position of an element closer to the surgeon or other operator and the term “distal” refers to the position of an element closer to the surgical end effector of the surgical instrument and further away from the surgeon or other operator. I. Exemplary Electrosurgical Instrument FIGS.1-3Cshow an exemplary electrosurgical instrument (100). As best seen inFIG.1, electrosurgical instrument (100) includes a handle assembly (120), a shaft assembly (140), an articulation assembly (110), and an end effector (180). As will be described in greater detail below, end effector (180) of electrosurgical instrument (100) is operable to grasp, cut, and seal or weld tissue (e.g., a blood vessel, etc.). In this example, end effector (180) is configured to seal or weld tissue by applying bipolar radio frequency (RF) energy to tissue. However, it should be understood electrosurgical instrument (100) may be configured to seal or weld tissue through any other suitable means that would be apparent to one skilled in the art in view of the teachings herein. For example, electrosurgical instrument (100) may be configured to seal or weld tissue via an ultrasonic blade, staples, etc. In the present example, electrosurgical instrument (100) is electrically coupled to a power source (not shown) via power cable (10). The power source may be configured to provide all or some of the electrical power requirements for use of electrosurgical instrument (100). Any suitable power source may be used as would be apparent to one skilled in the art in view of the teachings herein. By way of example only, the power source may comprise a GEN04 or GEN11 sold by Ethicon Endo-Surgery, Inc. of Cincinnati, Ohio. In addition, or in the alternative, the power source may be constructed in accordance with at least some of the teachings of U.S. Pat. No. 8,986,302, entitled “Surgical Generator for Ultrasonic and Electrosurgical Devices,” issued Mar. 24, 2015, the disclosure of which is incorporated by reference herein. While in the current example, electrosurgical instrument (100) is coupled to a power source via power cable (10), electrosurgical instrument (100) may contain an internal power source or plurality of power sources, such as a battery and/or supercapacitors, to electrically power electrosurgical instrument (100). Of course, any suitable combination of power sources may be utilized to power electrosurgical instrument (100) as would be apparent to one skilled in the art in view of the teaching herein. Handle assembly (120) is configured to be grasped by an operator with one hand, such that an operator may control and manipulate electrosurgical instrument (100) with a single hand. Shaft assembly (140) extends distally from handle assembly (120) and connects to articulation assembly (110). Articulation assembly (110) is also connected to a proximal end of end effector (180). As will be described in greater detail below, components of handle assembly (120) are configured to control end effector (180) such that an operator may grasp, cut, and seal or weld tissue. As will also be described in greater detail below, articulation assembly (110) is configured to deflect end effector (180) from the longitudinal axis defined by shaft assembly (140). Handle assembly (120) includes a body (122), a pistol grip (124), a jaw closure trigger (126), a knife trigger (128), an activation button (130), an articulation control (132), and a knob (134). As will be described in greater detail below, jaw closure trigger (126) may be pivoted toward and away from pistol grip (124) and/or body (122) to open and close jaws (182,184) of end effector (180) to grasp tissue. Additionally, knife trigger (128) may be pivoted toward and away from pistol grip (124) and/or body (122) to actuate a knife member (360) within the confines of jaws (182,184) to cut tissue captured between jaws (182,184). Further, activation button (130) may be pressed to apply radio frequency (RF) energy to tissue via electrode surfaces (194,196) of jaws (182,184), respectively. Body (122) of handle assembly (120) defines an opening (123) in which a portion of articulation control (132) protrudes from. Articulation control (132) is rotatably disposed within body (122) such that an operator may rotate the portion of articulation control (132) protruding from opening (123) to rotate the portion of articulation control (132) located within body (122). Rotation of articulation control (132) relative to body (122) is configured to bend articulation section (110) in order to drive deflection of end effector (180) from the longitudinal axis defined by shaft assembly (140). Articulation control (132) and articulation section (110) may include any suitable features to drive deflection of end effector (180) from the longitudinal axis defined by shaft assembly (140) as would be apparent to one skilled in the art in view of the teachings herein. Knob (134) is rotatably disposed on the distal end of body (122) and configured to rotate end effector (180), articulation assembly (110), and shaft assembly (140) about the longitudinal axis of shaft assembly (140) relative to handle assembly (120). While in the current example, end effector (180), articulation assembly (110), and shaft assembly (140) are rotated by knob (134), knob (134) may be configured to rotate end effector (180) and articulation assembly (110) relative to selected portions of shaft assembly (140). Knob (134) may include any suitable features to rotate end effector (180), articulation assembly (110), and shaft assembly (140) as would be apparent to one skilled in the art in view of the teachings herein. Shaft assembly (140) includes distal portion (142) extending distally from handle assembly (120), and a proximal portion (not shown) housed within the confines of body (122) of handle assembly (120). Shaft assembly (140) houses a jaw closure connector (338) that couples jaw closure trigger (126) with end effector (180). Additionally, shaft assembly (140) houses an actuating member that couples knife member (360) with knife trigger (128). Shaft assembly (140) also houses actuating members that couple articulation assembly (110) with articulation control (132); as well as an electrical connecter that operatively couples electrode surfaces (194,196) with activation button (130). As will be described in greater detail below, jaw closure connector (338) is configured to translate relative to shaft assembly (140) to open and close jaws (182,184) of end effector (180); while knife member (360) is coupled to knife trigger (128) of handle assembly (120) to translate a distal cutting edge (362) within the confines of end effector (180); and activation button (130) is configured to activate electrode surface (194,196). As best seen inFIGS.2-3C, end effector (180) includes lower jaw (182) pivotally coupled with an upper jaw (184) via pivot couplings (198). Lower jaw (182) includes a proximal body (183) defining a slot (186), while upper jaw (184) includes proximal arms (185) defining a slot (188). Lower jaw (182) also defines a central channel (190) that is configured to receive proximal arms (185) of upper jaw (184), portions of knife member (360), jaw closure connecter (338), and pin (350). Slots (186,188) each slidably receive pin (350), which is attached to a distal coupling portion (340) of jaw closure connector (338). As will be described in greater detail below, jaw closure connector (338) is operable to translate within central channel (190) of lower jaw (182). Translation of jaw closure connector (330) drives pin (350). As will be described in greater detail below, because pin (350) is located within both slots (186,188) and slots (186,188) are angled relative to each other, pin (350) cams against proximal arms (185) to pivot upper jaw (184) toward and away from lower jaw (182) about pivot couplings (198). Therefore, upper jaw (184) is configured to pivot toward and away from lower jaw (182) about pivot couplings (198) to grasp tissue. The term “pivot” does not necessarily require rotation about a fixed axis, but may include rotation about an axis that moves relative to end effector (180). Therefore, the axis at which upper jaw (184) pivots about lower jaw (182) may translate relative to both upper jaw (184) and lower jaw (182). Any suitable translation of the pivot axis may be used as would be apparent to one skilled in the art in view of the teachings herein. Lower jaw (182) and upper jaw (184) also define a knife pathway (192). Knife pathway (192) is configured to slidably receive knife member (360), such that knife member (360) may be retracted (as shown inFIGS.3A-3B), and advanced (as shown inFIG.3C), to cut tissue captured between jaws (182,184). Lower jaw (182) and upper jaw (184) each comprise a respective electrode surface (194,196). The power source may provide RF energy to electrode surfaces (194,196) via electrical coupling that extends through handle assembly (120), shaft assembly (140), articulation assembly (110), and electrically couples with one or both of electrode surfaces (194,196). Electrical coupling may selectively activate electrode surfaces (194,196) in response to an operator pressing activation button (130). FIGS.3A-3Cshow an exemplary use of instrument (100) for end effector (180) to grasp, cut, and seal/weld tissue. Jaw closure trigger (126) may be pivoted toward and away from pistol grip (124) and/or body (122) to open and close jaws (182,184) of end effector (180) to grasp tissue. In particular, pivoting jaw closure trigger (126) toward pistol grip (124) may proximally actuate jaw closure connector (338) and pin (350), which in turn cams against slots (188) of proximal arms (185) of upper jaw (184), thereby rotating upper jaw (184) about pivot couplings (198) toward lower jaw (182) such that jaws (182,184) achieve a closed configuration. If the operator desires to open jaws (182,184), the operator may pivot jaw closure trigger (126) away from pistol grip (124), such that pin (350) actuates distally to drive upper jaw (184) away from lower jaw (182). In some instances, jaw closure trigger (126) is biased toward the open position such that upper jaw (184) is biased to the open configuration. Any suitable features that cause pivoting of jaw closure trigger (126) to actuate pin (350) may be used as would be apparent to one skilled in the art in view of the teachings herein. Next, as shown betweenFIGS.3B-3C, knife trigger (128) may be pivoted toward and away from body (122) and/or pistol grip (124) to actuate knife member (360) within knife pathway (192) of jaws (182,184) to cut tissue captured between jaws (182,184). Any suitable features may be used in order to actuates knife member (360) as would be apparent to one skilled in the art in view of the teachings herein. In some instances, knife trigger (128) may be biased to the position associated with knife member (360) in a retracted position. With distal cutting edge (362) of knife member (360) actuated to the advance position (position shown inFIG.8C), an operator may press activation button (130) to selectively activate electrode surfaces (194,196) of jaws (182,184) to weld/seal severed tissue that is captured between jaws (182,184). It should be understood that the operator may also press activation button (130) to selectively activate electrode surfaces (194,196) of jaws (182,184) at any suitable time during exemplary use. Therefore, the operator may also press activation button (130) while knife member (360) is retracted as shown inFIGS.3A-3B. Next, the operator may release jaw closure trigger (128) such that jaws (182,184) pivot into the opened configuration, releasing tissue. II. Exemplary Alternative End Effector for Electrosurgical Instrument As mentioned above, end effector (180) is configured to grasp, sever, and weld/seal tissue. In particular, jaw (184) may pivot relative to jaw (182) in order to grasp tissue, while knife member (360) is configured to actuate within jaws (182,184) in order to sever grasped tissue. Electrode surfaces (194,196) may be activated while jaws (182,184) grasp tissue in order to weld/seal tissue captured between jaws (182,184). While welding/sealing tissue captured between jaws (182,184), an appropriate gap distance (d) between electrode surfaces (194,196) may be desirable along the entire length of electrode surfaces (194,196). If adjacent portions of electrode surfaces (194,196) that cooperatively grasp tissue form a gap distance (d) (as best shown inFIG.3B) that is too small, tissue grasped between electrode surfaces (194,196) may become damaged, crushed, etc. Additionally, if gap distance (d) is too small, electrode surfaces (194,196) may come into incidental contact with each other to cause an undesirable short circuit. Conversely, if adjacent portions of electrode surfaces (194,196) that cooperatively grasp tissue form a gap distance (d) that is too large, electrode surfaces (194,196) may not properly weld/seal tissue grasped between electrode surfaces (194,196). In some instances, the gap distance (d) between electrode surfaces (194,196) may deviate along the length of electrode surfaces (194,196) such that a proximal portion of electrode surfaces (194,196) form a gap distance (d) of a first size, and a distal portion of electrode surfaces (194,196) form a gap distance (d) of a second size. Therefore, in some instances, due at least in part to the deviation in gap distance (d), a first longitudinal portion of electrode surface (194,196) may create an acceptable tissue seal/weld, while a second longitudinal portion of electrode surfaces (194,196) may have too large or too small a gap distance that may cause undesirable effects as mention above. It may therefore be desirable to provide a form of end effector (180) that reliably provides a gap distance (d) that achieves the desired effects, while avoiding undesired effects, along the entire length of the tissue contacting region of the end effector. An example of such a form of end effector (180) is described in greater detail below. FIGS.4and8A-9Bshow an exemplary end effector (480) that may be readily incorporated into electrosurgical instrument (100) in replacement of end effector (180) described above. End effector (480) is substantially similar to end effector (180) described above, with differences elaborated below. As will be described in greater detail below, end effector (480) includes a tissue grasping assembly (410) that is configured to form an appropriate non-uniform gap distance (d1) along the length of tissue grasping portions (412,414) in order to promote an acceptable weld/seal of grasped tissue in accordance with the description herein. End effector (480) includes a lower jaw (482), an upper jaw (484), a proximal body (483) extending proximally from lower jaw (482), and a pair of proximal arms (485) extending proximally from upper jaw (483). Lower jaw (482), upper jaw (484), proximal body (483), and proximally extending arms (485) may be substantially similar to lower jaw (182), upper jaw (184), proximal body (183), and proximal arms (185) described above, with difference elaborated below. Therefore, proximal body (183) defines a central channel (490) and a slot (486), while proximal arms (485) define a slot (488), which are substantially similar to central channel (190), slot (186), and slot (188) described above, respectively. Additionally, lower jaw (482) and upper jaw (484) are pivotably coupled via pivot couplings (498), which may be substantially similar to pivot couplings (198) described above. Therefore, lower jaw (482) and upper jaw (484) are configured to pivot relative to each other about pivot couplings (498) in order to grasp tissue via translation of pin (350) within slots (186,188). Additionally, lower jaw (482) and upper jaw (484) define a knife pathway (492) dimensioned to slidably receive knife member (360) in accordance with the description herein. As mentioned above, end effector (480) also includes tissue grasping assembly (410). Tissue grasping assembly (410) includes lower tissue grasping portion (412) associated with lower jaw (482) and upper tissue grasping (414) portion associated with upper jaw (484). As best shown inFIGS.4and6, lower tissue grasping portion (412) includes an electrode surface (420) defining a plurality of pockets (422). Similar to electrode surface (194) described above, electrode surface (420) may be suitably coupled with a power source such that the power source may provide RF energy to electrode surface (420) via an electrical coupling. Therefore, the operator may selectively activate electrode surface (420) by pressing activation button (130) in accordance with the description above. Electrode surface (420) may be coupled to lower jaw (482) through any suitable means as would be apparent to one skilled in the art in view of the teachings herein. For example, electrode surface (420) may be coupled to lower jaw (484) via an adhesive, welding, an interference fit, a snap fitting, a latch, a dovetail joint, etc. Lower tissue grasping portion (412) also includes a pair of proximal teeth (424), a pair of middle teeth (426), and a pair of distal teeth (428). Each tooth (424,426,428) is housed within a respective pocket (422) defined by electrode surface (420). Teeth (424,426,428) are electrically insulated from electrode surface (420) while also extending above the electrode surface (420). Therefore, if any tooth (424,426,428) comes into contact with electrode surfaces (440,442) of upper jaw tissue grasping portion (414), a short circuit may be prevented. In the current example, teeth (424,426,428) have different heights relative to electrode surface (420). In particular, as shown inFIG.8A, distal teeth (428) extend to a first height (h1) above electrode surface (420); meddle teeth (426) extend to a second height (h2) above electrode surface (420); and proximal teeth (424) extend to a third height (h3) above electrode surface (420). In the present example, second height (h2) is greater than first height (h1); and third height (h3) is greater than second height (h2). Thus, teeth (428,426,428) progressively increase in height in the direction from the distal end of lower jaw (482) toward the proximal end of lower jaw (482). In some other versions, progressively decrease in height from the distal end of lower jaw (482) toward the proximal end of lower jaw (482), such that second height (h2) is less than first height (h1); and third height (h3) is less than second height (h2). In still other versions, teeth (428,426,428) are all at the same height relative to electrode surface (420). (424,426,428) may extend any suitable distance away from electrode surface (420) as would be apparent to one skilled in the art in view of the teachings herein. As will be described in greater detail below, distal teeth (428) and middle teeth (426) are configured to abut against distal tapered electrode surface (442) in order to impart a reactionary force to upper tissue grasping portion (414) as upper jaw (484) is pivoted into a completely closed configuration. The reactionary force imparted on upper tissue grasping portion (414), along with the compliant nature and geometry of upper tissue grasping portion (414), may induce a sufficient bending moment so electrode surfaces (440,442) and electrode surface (420) form an appropriate non-uniform gap distance (d1) between adjacent portions of electrode surface (420) and corresponding electrode surface (440,442). This appropriate gap distance (d1) may extend between a proximal end (448) and a distal end (450) of upper tissue grasping portion (414), though the gap distance (d1) may still slightly vary along the length extending between proximal end (448) and distal end (450). While in the current example, there are three sets of teeth (424,426,428) longitudinally spaced apart from each other, any suitable number of teeth (424,426,428) in any suitable array/pattern may be used as would be apparent to one skilled in the art in view of the teachings herein. As best shown inFIGS.4and7, upper tissue grasping portion (414) includes a proximal tapered electrode surface (440) and a distal tapered electrode surface (442) meeting at a juncture (444), such that upper jaw (484) is cambered. In some variations, lower jaw (482) may be cambered similar to how upper jaw (484) is cambered as described herein; in addition to upper jaw (484) being cambered as described herein. In still other variations, lower jaw (482) may be cambered similar to how upper jaw (484) is cambered as described herein; while upper jaw (484) is non-cambered. In the present example, similar to electrode surface (196) described above, electrode surfaces (440,442) may be suitably coupled with the power source such that the power source may provide RF energy to electrode surfaces (440,442) via an electrical coupling. Therefore, the operator may selectively activate electrode surfaces (440,442) by pressing activation button (130) in accordance with the description above. It should be understood that electrode surface (420) may cooperate with electrode surfaces (440,442) to apply bipolar RF energy to tissue that is captured between electrode surface (420) and electrode surfaces (440,442). Proximal tapered electrode surface (440) extends from a proximal end (448) to juncture (444) while distal tapered electrode surface (442) extends from juncture (444) to distal end (450). In particular, proximal tapered electrode surface (440) extends upwardly, as viewed from the perspective shown inFIG.7, from proximal end (448) to juncture (444); while distal tapered electrode surface (442) extends downwardly, as viewed from the perspective shown inFIG.7, from juncture (444) to distal end (450). Proximal tapered electrode surface (440) and distal tapered electrode surface (442) may be in electrical communication with each other. Additionally, proximal tapered electrode surface (440) and distal tapered electrode surface (442) may be unitarily formed as a single piece of material, may be formed with the same material, may be formed from two separate pieces of material, may be formed from different material, etc. A suitable portion of either one or both of electrode surface (440,442) defines a recess (446) dimensioned to align with proximal teeth (424) of lower tissue grasping portion (412) when jaws (482,484) are in the fully closed configuration, as will be described in greater detail below. Recess (446) is suitably sized such that when jaws (482,484) are in the fully closed configuration, proximal teeth (424) do not contact electrode surfaces (440,442). Proximal tapered electrode surface (440) and distal tapered electrode surface (442) are coupled with upper jaw (484) forming a general double taper such that when upper jaw (484) is pivoted to a position that initially makes contact with lower jaw (482), as shown inFIGS.8B and9A, the portions of tapered electrode surfaces (440,442) forming juncture (444) is furthest away from electrode surface (420) of lower jaw (482) compared to the portions of tapered electrode surfaces (440,442) at proximal end (448) and distal end (450), respectively. Juncture (444) may be located along any suitable longitudinal portion of upper jaw (484) as would be apparent to one skilled in the art in view of the teachings herein. Therefore, tapered electrode surface (440,442) may have any suitable length, length ratio, etc., as would be apparent to one skilled in the art in view of the teachings herein. While in the current example, juncture (444) extends linearly and perpendicular between lateral sides of electrode surfaces (440,442), this is merely optional. Juncture (444) may laterally extends across electrode surfaces (440,442) having any suitable geometry as would be apparent to one skilled in the art in view of the teachings herein. The general double taper formed by electrode surfaces (440,442) extending from juncture (444) to respective ends (448,450) may have any suitable angle relative to electrode surface (420) as would be apparent to one skilled in the art in view of the teachings herein. In the current example, the angles formed by tapered electrode surfaces (440,442) are exaggerated for purposes of clarity. Additionally, any suitable geometry of tapered electrode surfaces (440,442) may be used as would be apparent to one skilled in the art in view of teachings herein. For example, electrode surfaces (440,442) may have a substantially planar profile and generally rectangular perimeter. As another example, electrode surfaces (440,442) may extend from juncture (444) to respective ends (448,450) along a slightly arched profile, in either a slightly convex or concave, with a rounded, smooth, perimeter. As exemplified inFIG.7, distal electrode surface (442) may extend along an axis (A2) that defines an angle with a datum axis (A1) extending parallel to the longitudinal axis defined by shaft assembly (140). Similarly, proximal electrode surface (440) may also extend along an axis that defines another angle with datum axis (A1). The angles formed by tapered electrode surfaces (440,442) and datum axis (A1) may be formed through any suitably manner as would be apparent to one skilled in the art in view of the teaching herein. As best shown inFIG.7, the double taper formed in the current example is formed by a change in thickness of electrode surface (440,442) and corresponding portions of upper jaw (484) such that the thickness (t1) at juncture (444) is smaller than the thickness (t2) at proximal end (448) and the thickness (t3) at distal end (550). The changes in thickness forming double taper may be changes in thickness to upper jaw (484) alone, changes in thickness of electrode surfaces (440,442) alone, or a combination of both. Tapered electrode surfaces (440,442) may be coupled to upper jaw (484) through any suitable means as would be apparent to one skilled in the art in view of the teachings herein. For example, tapered electrode surface (440,442) may be coupled to upper jaw (484) via an adhesive, welding, an interference fit, a snap fitting, a latch, a dovetail joint, etc. Electrode surfaces (440,442), as well as any other suitable components of upper tissue grasping portion (414) and upper jaw (484), may be suitably compliable, elastically deformable, resilient, etc., to deform in response to a suitable bending moment. It should be understood that electrode surfaces (420,440,442) may be formed from any suitable material as would be apparent to one skilled in the art in view of the teachings herein. As will be described in greater detail below, electrode surfaces (440,442) are suitably elastically deformable, such that electrode surfaces (440,442) form an appropriate non-uniform gap distance (d1) when upper jaw (484) is pivoted from an initially closed position into a fully closed position. FIGS.8A-9Bshow an exemplary use of end effector (480) in accordance with the description herein.FIG.8Ashows end effector (480) in an open position such that lower tissue grasping portion (412) and upper tissue grasping portion (414) are configured to accept tissue between both portions (412,414). While end effector (480) is in the open position, tapered electrode surfaces (440,442) form the double taper as described above. Next, as shown inFIGS.8B and9A, the operator may pivot upper jaw (484) toward lower jaw (482) by pulling closure trigger (126) to proximally translate pin (350) in accordance with the description herein. In particular, the operator may pivot upper jaw (484) toward lower jaw (482) until distal tapered electrode surface (442) initially contacts distal teeth (428). At the position shown inFIGS.8B and9A, proximal tapered electrode surface (440) is not parallel with electrode surface (420); and distal tapered electrode surface (442) is not parallel with electrode surface (420). Also at the position shown inFIGS.8B and9A, contact between distal tapered electrode surface (442) and distal teeth (428) does not impart a sufficient reactionary force on upper jaw (484) and tapered electrode surfaces (440,442) to induce a sufficient bending moment on electrode surfaces (440,442). Therefore, tapered electrode surfaces (440,442) maintain their initial geometry such that junction (444) is further away from an adjacent portion of electrode surface (420) as compared to proximal end (448) and distal end (450) of respective tapered electrode surfaces (440,442). Therefore, at the position shown inFIGS.8B and9A, the gap distance between tapered electrode surfaces (440,442) and electrode surface (420) is not substantially uniform along the length of tissue grasping portions (412,414). To further illustrate the non-parallel relationship between electrode surfaces (440,442) and electrode surface (420) at the state shown inFIGS.8B and9A,FIG.10depicts a plot (500) showing an example of a gap distance between electrode surfaces (440,442) and electrode surface (420) as a function of the distance from distal end (450) of upper tissue grasping portion (414). It should be understood that the numerical values shown inFIG.10are merely illustrative examples and are not intended to be limiting in any way. InFIG.10, a first segment (502) of plot (500) corresponds to the gap distance between distal tapered electrode surface (440) and lower electrode surface (420); while a second segment (504) of plot (500) corresponds to the gap distance between proximal tapered electrode surface (440) and lower electrode surface (420). Also inFIG.10, a first broken vertical line (510) corresponds to the longitudinal position of distal tooth (428), a second broken vertical line (520) corresponds to the longitudinal position of middle tooth (426), and a third broken vertical line (530) corresponds to the longitudinal position of proximal tooth (424). Next, as shown inFIGS.8C and9B, the operator may further pivot upper jaw (484) toward lower jaw (482) by further pulling closure trigger (126) to further proximally translate pin (350) in accordance with the description herein until closure trigger (126) is latched and/or pivoted to its completely closed position. Further proximal translation of pin (350) may impart a sufficient reactionary force on upper jaw (484) and tapered electrode surfaces (440,442) from contact with distal teeth (428) to induce a sufficient bending moment on electrode surfaces (440,442). The induced bending moment may cause distal tapered electrode (442) to contact middle teeth (426) so middle teeth (426) also impart a reactionary force on upper jaw (484) and tapered electrode surfaces (440,442). The portion of distal tapered electrode surface (442) located distal to middle teeth (426) may define a portion of gap distance (d1) with adjacent portions of electrode surface (420) through contact with middle teeth (426) and distal teeth (428). Additionally, the bending moment generated by further proximal translation of pin (350) may bend/elastically deform the portion of distal tapered electrode surface (442) located proximal to middle teeth (426), juncture (444), and proximal tapered electrode (442) closer to adjacent portions of electrode surface (420) to also define a portion of gap distance (d1). Therefore, gap distance (d1) may extend between a proximal end (448) and a distal end (450) of upper tissue grasping portion (414). However, in the present example, gap distance (d1) is not uniform along the entire length extending between proximal end (448) and distal end (450), even in the state shown inFIGS.8C and9B. In other words, even in the state shown inFIGS.8C and9B, proximal tapered electrode surface (440) is still not parallel with electrode surface (420); and distal tapered electrode surface (442) is still not parallel with electrode surface (420). Nevertheless, the distance between juncture (444) and electrode surface (420) in the state shown inFIGS.8C and9Bis still smaller than the distance between juncture (444) and electrode surface (420) in the state shown inFIGS.8B and9A. In some other variations, gap distance (d1) may be uniform along the length of electrode surfaces (420,440,442) in the state shown inFIGS.8C and9B, such that electrode surfaces (440,442) may be parallel with electrode surface (420) in the state shown inFIGS.8C and9B. To further illustrate the non-parallel relationship between electrode surfaces (440,442) and electrode surface (420) at the state shown inFIGS.8C and9B,FIG.11depicts a plot (550) showing an example of a gap distance between electrode surfaces (440,442) and electrode surface (420) as a function of the distance from distal end (450) of upper tissue grasping portion (414).FIG.11may be regarded as being drawn to scale with respect to some versions of end effector (480). It should be understood that the numerical values shown inFIG.11are merely illustrative examples and are not intended to be limiting in any way. InFIG.11, a first segment (552) of plot (550) corresponds to the gap distance between distal tapered electrode surface (440) and lower electrode surface (420); while a second segment (554) of plot (550) corresponds to the gap distance between proximal tapered electrode surface (440) and lower electrode surface (420). Also inFIG.11, broken vertical lines (510,520,530) corresponds to the longitudinal position of teeth (428,426,424) in the same manner as found inFIG.10. By way of further example only, at the state shown inFIGS.8C and9B,FIG.11, the gap distance between proximal end (448) of upper tissue grasping portion (414) and lower electrode surface (420) may range from approximately 0.001 inches to approximately 0.006 inches By way of further example only, at the state shown inFIGS.8C and9B,FIG.11, the gap distance between juncture (444) of upper tissue grasping portion (414) and lower electrode surface (420) may range from approximately 0.001 inches to approximately 0.006 inches By way of further example only, at the state shown inFIGS.8C and9B,FIG.11, the gap distance between distal end (450) of upper tissue grasping portion (414) and lower electrode surface (420) may range from approximately 0.001 inches to approximately 0.006 inches The foregoing gap value ranges are merely illustrative examples and are not intended to be limiting in any way. By way of further example only, the gap distance between upper electrode surfaces (440,442) and lower electrode surface (420) may vary along the length of electrode surfaces (420,440,442) (i.e., the length between proximal end (448) and distal end (450), including juncture (444)), from the largest gap distance to the smallest gap distance, by a percentage range from approximately 10% to approximately 80%, with the largest gap distance being at juncture (444). The foregoing gap change percentage range is a merely illustrative example and is not intended to be limiting in any way. In some scenarios, contact generated between distal tapered electrode surface (442) and teeth (426,428) may also be sufficient to slightly deform lower jaw (482) from a first vertical position (p1) to a second, lowered vertical position (p2). Deformation of lower jaw (482) may also help achieve a desirable yet non-uniform final gap distance (d1). As best seen inFIG.9B, proximal teeth (424) are housed within recess (446) of electrode surfaces (440,442) when final gap distance (d1) is formed such that proximal teeth (424) do not contact any surface of recess (446) or either electrode surface (440,442). Therefore, proximal teeth (424) may not impart another reactionary force on upper jaw (484) and tapered electrode surface (440,442) in the present example. The absence of reactionary force generated by contact with proximal teeth (424) and electrode surface (440,442) may help assure the bending moment within electrode surfaces (440,442) is sufficient to elastically deform electrode surfaces (440,442) to sufficiently define the appropriate, non-uniform final gap distance (d1) along the entire length of electrode surfaces (440,442). With an appropriate, non-uniform final gap distance (d1) created, the operator may activate electrode surface (420,440,442) in accordance with the description herein. Additionally, the operator may sever tissue captured between electrode surfaces (420,440,442) in accordance with the description herein. With the appropriate, non-uniform final gap distance (d1) created along the length of tissue grasping assembly (410), the tissue captured along the entire length of electrodes (420,440,442) may be suitably sealed/welded without damaging/crushing any portion of the grasped tissue. Next, the operator may distally translate pin (350) such that upper jaw (484) pivots away from lower jaw (482), thereby removing the reactionary force imparted on electrode surfaces (440,442) and upper jaw (484) from teeth (426,428). Due to the resilient nature of electrodes (440,442), the removal of the reactionary force allows electrode surfaces (440,442) to return to their original shape as shown inFIGS.8A-8BandFIG.9A. Since proximal teeth (424) are dimensioned to be housed within recess (446) of upper tissue grasping portion (414), in some instances, proximal teeth (424) may be omitted. In some instances, proximal teeth (424) may be electrically coupled with electrode surface (420). In the current example, middle teeth (426) and distal teeth (428) together define a distal portion of gap distance (d1) while also preventing electrode surface (420) from accidentally contacting correspond surfaces (440,442). However, this is merely optional. In instances where distal teeth (428) extend further from electrode surface (420) as compared to middle teeth (426), distal teeth (428) alone may be used to define gap distance (d1). In instances where middle teeth (426) extend further from electrode surface (420) as compared to distal teeth (428), middle teeth (426) alone may be used to define gap distance (d1). III. Exemplary Combinations The following examples relate to various non-exhaustive ways in which the teachings herein may be combined or applied. It should be understood that the following examples are not intended to restrict the coverage of any claims that may be presented at any time in this application or in subsequent filings of this application. No disclaimer is intended. The following examples are being provided for nothing more than merely illustrative purposes. It is contemplated that the various teachings herein may be arranged and applied in numerous other ways. It is also contemplated that some variations may omit certain features referred to in the below examples. Therefore, none of the aspects or features referred to below should be deemed critical unless otherwise explicitly indicated as such at a later date by the inventors or by a successor in interest to the inventors. If any claims are presented in this application or in subsequent filings related to this application that include additional features beyond those referred to below, those additional features shall not be presumed to have been added for any reason relating to patentability. Example 1 An apparatus comprising: (a) a body; (b) a shaft assembly extending distally from the body; and (c) an end effector configured to grasp tissue and transmit RF energy to the grasped tissue, wherein the end effector comprises: (i) a first jaw member comprising a first tissue grasping feature, and (ii) a second jaw member, wherein the second jaw member is pivotably coupled to the first jaw member between an open position, a partially closed position, and a closed position, wherein the second jaw member comprises: (A) a proximal taper comprising a proximal electrode surface terminating at a proximal end, (B) a distal taper comprising a distal electrode surface terminating at a distal end, and (C) a juncture interposed between the proximal electrode surface and the distal electrode surface, wherein the juncture is configured to be spaced further from the first tissue grasping feature compared to the proximal end and the distal end while the second jaw is in the partially closed position, wherein the proximal electrode surface and the distal electrode surface are configured to deform to define a gap with the first tissue grasping feature between the proximal end and the distal end while in the closed position. Example 2 The apparatus of Example 1, wherein the first tissue grasping feature comprises an electrode surface and a distal pair of teeth electrically insulated from the electrode surface. Example 3 The apparatus of Example 2, wherein the distal electrode surface is configured to contact the distal pair of teeth in the partially closed position and the fully closed position. Example 4 The apparatus of Example 3, wherein the distal pair of teeth extend away from the electrode surface in order to define the gap distance. Example 5 The apparatus of any one or more of Examples 1 through 4, wherein the juncture comprises a first thickness, wherein the distal end comprises a second thickness, wherein the first thickness is smaller than the second thickness. Example 6 The apparatus of Example 5, wherein the proximal end comprises a third thickness, wherein the first thickness is smaller than the third thickness. Example 7 The apparatus of any one or more of Examples 1 through 6, wherein the first tissue grasping feature comprises an electrode surface, a distal pair of teeth electrically insulated from the electrode surface, and a second pair of teeth. Example 8 The apparatus of Example 7, wherein the second pair of teeth are proximal relative to the distal pair of teeth. Example 9 The apparatus of Example 8, wherein the second pair of teeth are configured to contact the distal electrode surface in the closed position. Example 10 The apparatus of Example 9, wherein the second pair of teeth are configured to be spaced away from the distal electrode surface in the partially closed position. Example 11 The apparatus of any one or more of Examples 8 through 10, wherein either the proximal electrode surface or the distal electrode surface defines a recess, wherein the recess is dimensioned to house the second pair of teeth in the closed position. Example 12 The apparatus of any one or more of Examples 1 through 11, wherein the body comprises a handle assembly. Example 13 The apparatus of Example 12, wherein the handle assembly further comprises a jaw closure trigger, wherein the jaw closure trigger is configured to pivot the second jaw between the open position, the partially closed position, and the fully closed position. Example 14 The apparatus of any one or more of Examples 12 through 13, wherein the handle assembly comprises an activation button configured to transmit RF energy to the proximal electrode surface and the distal electrode surface. Example 15 The apparatus of any one or more of Examples 1 through 14, wherein the proximal electrode surface and the distal electrode surface are configured to deform to define a non-uniform gap with the first tissue grasping feature between the proximal end and the distal end while in the closed position. Example 16 An apparatus comprising: (a) a body; and (b) an end effector located distally relative to the body, wherein the end effector is configured to grasp tissue and transmit RF energy to the grasped tissue, wherein the end effector comprises: (i) a first jaw member, and (ii) a second jaw member, wherein the second jaw member is pivotably coupled to the first jaw member between an open position, a partially closed position, and a closed position, wherein the second jaw member comprises a double tapered electrode surface comprising a proximal taper and a distal taper connected at a juncture, wherein the juncture is configured to be spaced further from the first tissue grasping feature compared to the proximal taper and the distal taper while the second jaw is in the partially closed position, wherein the proximal taper and the distal taper are configured to deform to define a gap with the first jaw member while in the closed position. Example 17 The apparatus of Example 16, wherein the first jaw member comprises an electrode surface. Example 18 The apparatus of Example 17, wherein the first jaw member comprises at least one tooth electrically insulated from the electrode surface of the first jaw member. Example 19 The apparatus of Example 18, wherein the at least one tooth is configured to contact the distal taper while the second jaw is in the closed position. Example 20 An apparatus comprising: (a) a body; (b) a shaft assembly extending distally from the body; and (c) an end effector configured to grasp tissue and transmit RF energy to the grasped tissue, wherein the end effector comprises: (i) a first jaw member, (ii) a second jaw member, wherein the second jaw member is pivotably coupled to the first jaw member between an open position, a partially closed position, and a closed position, and (iii) a tissue grasping assembly, comprising (A) a first tissue grasping feature associated with the first jaw member, and (B) a second tissue grasping feature associated with the second jaw member, wherein the second tissue grasping feature comprises a compliant electrode surface, wherein the compliant electrode surface is configured to form a double taper while the second jaw is in the open position and the partially closed position, wherein the compliant electrode surface is configured to deform to define a gap distance with the first tissue grasping feature while in the closed position. IV. Miscellaneous It should be understood that any of the versions of the instruments described herein may include various other features in addition to or in lieu of those described above. By way of example only, any of the devices herein may also include one or more of the various features disclosed in any of the various references that are incorporated by reference herein. For instance, the teachings herein may be readily combined with various teachings in U.S. Pat. No. 9,526,565, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 9,492,224, the disclosure of which is incorporated by reference herein; and/or U.S. Pat. No. 10,292,758, the disclosure of which is incorporated by reference herein. Various suitable ways in which such teachings may be combined will be apparent to those of ordinary skill in the art. It should also be understood that any of the devices described herein may be modified to include a motor or other electrically powered device to drive an otherwise manually moved component. Various examples of such modifications are described in U.S. Pat. No. 9,161,803, entitled “Motor Driven Electrosurgical Device with Mechanical and Electrical Feedback,” issued Oct. 20, 2015, the disclosure of which is incorporated by reference herein. Various other suitable ways in which a motor or other electrically powered device may be incorporated into any of the devices herein will be apparent to those of ordinary skill in the art in view of the teachings herein. It should also be understood that any of the devices described herein may be modified to contain most, if not all, of the required components within the medical device itself. More specifically, the devices described herein may be adapted to use an internal or attachable power source instead of requiring the device to be plugged into an external power source by a cable. Various examples of how medical devices may be adapted to include a portable power source are disclosed in U.S. Provisional Application Ser. No. 61/410,603, filed Nov. 5, 2010, entitled “Energy-Based Surgical Instruments,” the disclosure of which is incorporated by reference herein. Various other suitable ways in which a power source may be incorporated into any of the devices herein will be apparent to those of ordinary skill in the art in view of the teachings herein. In versions where the teachings herein are applied to an ultrasonic surgical instrument, it should be understood that some such instruments may lack a translating firing beam. The components described herein for translating a firing beam may instead simply translate a jaw closing member. Alternatively, such translating features may simply be omitted. In any case, it should be understood that the teachings herein may be combined with the teachings of one or more of the following: U.S. Pat. Pub. No. 2006/0079874, entitled “Tissue Pad for Use with an Ultrasonic Surgical Instrument,” published Apr. 13, 2006, now abandoned, the disclosure of which is incorporated by reference herein; U.S. Pat. Pub. No. 2007/0191713, entitled “Ultrasonic Device for Cutting and Coagulating,” published Aug. 16, 2007, now abandoned, the disclosure of which is incorporated by reference herein; U.S. Pat. Pub. No. 2007/0282333, entitled “Ultrasonic Waveguide and Blade,” published Dec. 6, 2007, now abandoned, the disclosure of which is incorporated by reference herein; U.S. Pat. Pub. No. 2008/0200940, entitled “Ultrasonic Device for Cutting and Coagulating,” published Aug. 21, 2008, now abandoned, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 8,461,744, entitled “Rotating Transducer Mount for Ultrasonic Surgical Instruments,” issued on Jun. 11, 2013, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 6,500,176, entitled “Electrosurgical Systems and Techniques for Sealing Tissue,” issued Dec. 31, 2002, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 8,939,974, entitled “Surgical Instrument Comprising First and Second Drive Systems Actuatable by a Common Trigger Mechanism,” issued Jan. 27, 2015, the disclosure of which is incorporated by reference herein; and/or U.S. Pat. No. 6,783,524, entitled “Robotic Surgical Tool with Ultrasound Cauterizing and Cutting Instrument,” issued Aug. 31, 2004, the disclosure of which is incorporated by reference herein. Other suitable ways in which the teachings herein may be applied to an ultrasonic surgical instrument will be apparent to those of ordinary skill in the art in view of the teachings herein. It should be understood that any one or more of the teachings, expressions, embodiments, examples, etc. described herein may be combined with any one or more of the other teachings, expressions, embodiments, examples, etc. that are described herein. The above-described teachings, expressions, embodiments, examples, etc. should therefore not be viewed in isolation relative to each other. Various suitable ways in which the teachings herein may be combined will be readily apparent to those of ordinary skill in the art in view of the teachings herein. Such modifications and variations are intended to be included within the scope of the claims. It should be appreciated that any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material. Versions of the devices described above may have application in conventional medical treatments and procedures conducted by a medical professional, as well as application in robotic-assisted medical treatments and procedures. By way of example only, various teachings herein may be readily incorporated into a robotic surgical system such as the DAVINCI™ system by Intuitive Surgical, Inc., of Sunnyvale, Calif. Similarly, those of ordinary skill in the art will recognize that various teachings herein may be readily combined with various teachings of U.S. Pat. No. 6,783,524, entitled “Robotic Surgical Tool with Ultrasound Cauterizing and Cutting Instrument,” published Aug. 31, 2004, the disclosure of which is incorporated by reference herein. Versions described above may be designed to be disposed of after a single use, or they can be designed to be used multiple times. Versions may, in either or both cases, be reconditioned for reuse after at least one use. Reconditioning may include any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, some versions of the device may be disassembled, and any number of the particular pieces or parts of the device may be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, some versions of the device may be reassembled for subsequent use either at a reconditioning facility, or by an operator immediately prior to a procedure. Those skilled in the art will appreciate that reconditioning of a device may utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application. By way of example only, versions described herein may be sterilized before and/or after a procedure. In one sterilization technique, the device is placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and device may then be placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation may kill bacteria on the device and in the container. The sterilized device may then be stored in the sterile container for later use. A device may also be sterilized using any other technique known in the art, including but not limited to beta or gamma radiation, ethylene oxide, or steam. Having shown and described various embodiments of the present invention, further adaptations of the methods and systems described herein may be accomplished by appropriate modifications by one of ordinary skill in the art without departing from the scope of the present invention. Several of such potential modifications have been mentioned, and others will be apparent to those skilled in the art. For instance, the examples, embodiments, geometrics, materials, dimensions, ratios, steps, and the like discussed above are illustrative and are not required. Accordingly, the scope of the present invention should be considered in terms of the following claims and is understood not to be limited to the details of structure and operation shown and described in the specification and drawings.

11857248

DETAILED DESCRIPTION OF THE INVENTION In general, an electrosurgical ablation system is described herein that comprises an elongated introducer member for accessing a patient's uterine cavity with a working end that deploys an expandable thin-wall dielectric structure containing an electrically non-conductive gas as a dielectric. In one embodiment, an interior chamber of the thin-wall dielectric structure contains a circulating neutral gas such as argon. An RF power source provides current that is coupled to the neutral gas flow by a first polarity electrode disposed within the interior chamber and a second polarity electrode at an exterior of the working end. The gas flow, which is converted to a conductive plasma by an electrode arrangement, functions as a switching mechanism that permits current flow to engaged endometrial tissue only when the voltage across the combination of the gas, the thin-wall dielectric structure and the engaged tissue reaches a threshold that causes capacitive coupling across the thin-wall dielectric material. By capacitively coupling current to tissue in this manner, the system provides a substantially uniform tissue effect within all tissue in contact with the expanded dielectric structure. Further, the invention allows the neutral gas to be created contemporaneously with the capacitive coupling of current to tissue. In general, this disclosure may use the terms “plasma,” “conductive gas” and “ionized gas” interchangeably. A plasma consists of a state of matter in which electrons in a neutral gas are stripped or “ionized” from their molecules or atoms. Such plasmas can be formed by application of an electric field or by high temperatures. In a neutral gas, electrical conductivity is non-existent or very low. Neutral gases act as a dielectric or insulator until the electric field reaches a breakdown value, freeing the electrons from the atoms in an avalanche process thus forming a plasma. Such a plasma provides mobile electrons and positive ions, and acts as a conductor which supports electric currents and can form spark or arc. Due to their lower mass, the electrons in a plasma accelerate more quickly in response to an electric field than the heavier positive ions, and hence carry the bulk of the current. FIG.1depicts one embodiment of an electrosurgical ablation system100configured for endometrial ablation. The system100includes a hand-held apparatus105with a proximal handle106shaped for grasping with a human hand that is coupled to an elongated introducer sleeve110having axis111that extends to a distal end112. The introducer sleeve110can be fabricated of a thin-wall plastic, composite, ceramic or metal in a round or oval cross-section having a diameter or major axis ranging from about 4 mm to 8 mm in at least a distal portion of the sleeve that accesses the uterine cavity. The handle106is fabricated of an electrically insulative material such as a molded plastic with a pistol-grip having first and second portions,114aand114b, that can be squeezed toward one another to translate an elongated translatable sleeve115which is housed in a bore120in the elongated introducer sleeve110. By actuating the first and second handle portions,114aand114b, a working end122can be deployed from a first retracted position (FIG.1) in the distal portion of bore120in introducer sleeve110to an extended position as shown inFIG.2. InFIG.2, it can be seen that the first and second handle portions,114aand114b, are in a second actuated position with the working end122deployed from the bore120in introducer sleeve110. FIGS.2and3shows that ablation system100includes an RF energy source130A and RF controller130B in a control unit135. The RF energy source130A is connected to the hand-held device105by a flexible conduit136with a plug-in connector137configured with a gas inflow channel, a gas outflow channel, and first and second electrical leads for connecting to receiving connector138in the control unit135. The control unit135, as will be described further below inFIGS.3and4, further comprises a neutral gas inflow source140A, gas flow controller140B and optional vacuum or negative pressure source145to provide controlled gas inflows and gas outflows to and from the working end122. The control unit135further includes a balloon inflation source148for inflating an expandable sealing balloon225carried on introducer sleeve110as described further below. Referring toFIG.2, the working end122includes a flexible, thin-wall member or structure150of a dielectric material that when expanded has a triangular shape configured for contacting the patient's endometrial lining that is targeted for ablation. In one embodiment as shown inFIGS.2,5and6, the dielectric structure150comprises a thin-wall material such as silicone with a fluid-tight interior chamber152. In an embodiment, an expandable-collapsible frame assembly155is disposed in the interior chamber. Alternatively, the dielectric structure may be expanded by a neutral gas without a frame, but using a frame offers a number of advantages. First, the uterine cavity is flattened with the opposing walls in contact with one another. Expanding a balloon-type member may cause undesirable pain or spasms. For this reason, a flat structure that is expanded by a frame is better suited for deployment in the uterine cavity. Second, in embodiments herein, the neutral gas is converted to a conductive plasma at a very low pressure controlled by gas inflows and gas outflows—so that any pressurization of a balloon-type member with the neutral gas may exceed a desired pressure range and would require complex controls of gas inflows and gas outflows. Third, as described below, the frame provides an electrode for contact with the neutral gas in the interior chamber152of the dielectric structure150, and the frame155extends into all regions of the interior chamber to insure electrode exposure to all regions of the neutral gas and plasma. The frame155can be constructed of any flexible material with at least portions of the frame functioning as spring elements to move the thin-wall structure150from a collapsed configuration (FIG.1) to an expanded, deployed configuration (FIG.2) in a patient's uterine cavity. In one embodiment, the frame155comprises stainless steel elements158a,158band160aand160bthat function akin to leaf springs. The frame can be a stainless steel such as 316 SS, 17A SS, 420 SS, 440 SS or the frame can be a NiTi material. The frame preferably extends along a single plane, yet remains thin transverse to the plane, so that the frame may expand into the uterine cavity. The frame elements can have a thickness ranging from about 0.005″ to 0.025″. As can be seen inFIGS.5and6, the proximal ends162aand162bof spring elements158a,158bare fixed (e.g., by welds164) to the distal end165of sleeve member115. The proximal ends166aand166bof spring elements160a,160bare welded to distal portion168of a secondary translatable sleeve170that can be extended from bore175in translatable sleeve115. The secondary translatable sleeve170is dimensioned for a loose fit in bore175to allow gas flows within bore175.FIGS.5and6further illustrate the distal ends176aand176bof spring elements158a,158bare welded to distal ends178aand178bof spring elements160aand160bto thus provide a frame155that can be moved from a linear shape (seeFIG.1) to an expanded triangular shape (FIGS.5and6). As will be described further below, the bore175in sleeve115and bore180in secondary translatable sleeve170function as gas outflow and gas inflow lumens, respectively. It should be appreciated that the gas inflow lumen can comprise any single lumen or plurality of lumens in either sleeve115or sleeve170or another sleeve, or other parts of the frame155or the at least one gas flow lumen can be formed into a wall of dielectric structure150. InFIGS.5,6and7it can be seen that gas inflows are provided through bore180in sleeve170, and gas outflows are provided in bore175of sleeve115. However, the inflows and outflows can be also be reversed between bores175and180of the various sleeves.FIGS.5and6further show that a rounded bumper element185is provided at the distal end of sleeve170to insure that no sharp edges of the distal end of sleeve170can contact the inside of the thin dielectric wall150. In one embodiment, the bumper element185is silicone, but it could also comprise a rounded metal element.FIGS.5and6also show that a plurality of gas inflow ports188can be provided along a length of in sleeve170in chamber152, as well as a port190in the distal end of sleeve170and bumper element185. The sectional view ofFIG.7also shows the gas flow passageways within the interior of introducer sleeve110. It can be understood fromFIGS.1,2,5and6that actuation of first and second handle portions,114aand114b, (i) initially causes movement of the assembly of sleeves115and170relative to bore120of introducer sleeve110, and (ii) secondarily causes extension of sleeve170from bore175in sleeve115to expand the frame155into the triangular shape ofFIG.5. The dimensions of the triangular shape are suited for a patient uterine cavity, and for example can have an axial length A ranging from 4 to 10 cm and a maximum width B at the distal end ranging from about 2 to 5 cm. In one embodiment, the thickness C of the thin-wall structure150can be from 1 to 4 mm as determined by the dimensions of spring elements158a,158b,160aand160bof frame assembly155. It should be appreciated that the frame assembly155can comprise round wire elements, flat spring elements, of any suitable metal or polymer that can provide opening forces to move thin-wall structure150from a collapsed configuration to an expanded configuration within the patient uterus. Alternatively, some elements of the frame155can be spring elements and some elements can be flexible without inherent spring characteristics. As will be described below, the working end embodiment ofFIGS.2,5and6has a thin-wall structure150that is formed of a dielectric material such as silicone that permits capacitive coupling of current to engaged tissue while the frame assembly155provides structural support to position the thin-wall structure150against tissue. Further, gas inflows into the interior chamber152of the thin-wall structure can assist in supporting the dielectric wall so as to contact endometrial tissue. The dielectric thin-wall structure150can be free from fixation to the frame assembly155, or can be bonded to an outward-facing portion or portions of frame elements158aand158b. The proximal end182of thin-wall structure150is bonded to the exterior of the distal end of sleeve115to thus provide a sealed, fluid-tight interior chamber152(FIG.5). In one embodiment, the gas inflow source140A comprises one or more compressed gas cartridges that communicate with flexible conduit136through plug-in connector137and receiving connector138in the control unit135(FIGS.1-2). As can be seen inFIGS.5-6, the gas inflows from source140A flow through bore180in sleeve170to open terminations188and190therein to flow into interior chamber152. A vacuum source145is connected through conduit136and connector137to allow circulation of gas flow through the interior chamber152of the thin-wall dielectric structure150. InFIGS.5and6, it can be seen that gas outflows communicate with vacuum source145through open end200of bore175in sleeve115. Referring toFIG.5, it can be seen that frame elements158aand158bare configured with a plurality of apertures202to allow for gas flows through all interior portions of the frame elements, and thus gas inflows from open terminations188,190in bore180are free to circulated through interior chamber152to return to an outflow path through open end200of bore175of sleeve115. As will be described below (seeFIGS.3-4), the gas inflow source140A is connected to a gas flow or circulation controller140B which controls a pressure regulator205and also controls vacuum source145which is adapted for assisting in circulation of the gas. It should be appreciated that the frame elements can be configured with apertures, notched edges or any other configurations that allow for effective circulation of a gas through interior chamber152of the thin-wall structure150between the inflow and outflow passageways. Now turning to the electrosurgical aspects of the invention,FIGS.5and6illustrate opposing polarity electrodes of the system100that are configured to convert a flow of neutral gas in chamber152into a plasma208(FIG.6) and to allow capacitive coupling of current through a wall210of the thin-wall dielectric structure150to endometrial tissue in contact with the wall210. The electrosurgical methods of capacitively coupling RF current across a plasma208and dielectric wall210are described in U.S. patent application Ser. No. 12/541,043; filed Aug. 13, 2009 and U.S. application Ser. No. 12/541,050, referenced above. InFIGS.5and6, the first polarity electrode215is within interior chamber152to contact the neutral gas flow and comprises the frame assembly155that is fabricated of an electrically conductive stainless steel. In another embodiment, the first polarity electrode can be any element disposed within the interior chamber152, or extendable into interior chamber152. The first polarity electrode215is electrically coupled to sleeves115and170which extends through the introducer sleeve110to handle106and conduit136and is connected to a first pole of the RF source energy source130A and controller130B. A second polarity electrode220is external of the internal chamber152and in one embodiment the electrode is spaced apart from wall210of the thin-wall dielectric structure150. In one embodiment as depicted inFIGS.5and6, the second polarity electrode220comprises a surface element of an expandable balloon member225carried by introducer sleeve110. The second polarity electrode220is coupled by a lead (not shown) that extends through the introducer sleeve110and conduit136to a second pole of the RF source130A. It should be appreciated that second polarity electrode220can be positioned on sleeve110or can be attached to surface portions of the expandable thin-wall dielectric structure150, as will be described below, to provide suitable contact with body tissue to allow the electrosurgical ablation of the method of the invention. The second polarity electrode220can comprise a thin conductive metallic film, thin metal wires, a conductive flexible polymer or a polymeric positive temperature coefficient material. In one embodiment depicted inFIGS.5and6, the expandable member225comprises a thin-wall compliant balloon having a length of about 1 cm to 6 cm that can be expanded to seal the cervical canal. The balloon225can be inflated with a gas or liquid by any inflation source148, and can comprise a syringe mechanism controlled manually or by control unit135. The balloon inflation source148is in fluid communication with an inflation lumen228in introducer sleeve110that extends to an inflation chamber of balloon225(seeFIG.7). Referring back toFIG.1, the control unit135can include a display230and touch screen or other controls232for setting and controlling operational parameters such as treatment time intervals, treatment algorithms, gas flows, power levels and the like. Suitable gases for use in the system include argon, other noble gases and mixtures thereof. In one embodiment, a footswitch235is coupled to the control unit135for actuating the system. The box diagrams ofFIGS.3and4schematically depict the system100, subsystems and components that are configured for an endometrial ablation system. In the box diagram ofFIG.3, it can be seen that RF energy source130A and circuitry is controlled by a controller130B. The system can include feedback control systems that include signals relating to operating parameters of the plasma in interior chamber152of the dielectric structure150. For example, feedback signals can be provided from at least one temperature sensor240in the interior chamber152of the dielectric structure150, from a pressure sensor within, or in communication, with interior chamber152, and/or from a gas flow rate sensor in an inflow or outflow channel of the system.FIG.4is a schematic block diagram of the flow control components relating to the flow of gas media through the system100and hand-held device105. It can be seen that a pressurized gas source140A is linked to a downstream pressure regulator205, an inflow proportional valve246, flow meter248and normally closed solenoid valve250. The valve250is actuated by the system operator which then allows a flow of a neutral gas from gas source140A to circulate through flexible conduit136and the device105. The gas outflow side of the system includes a normally open solenoid valve260, outflow proportional valve262and flow meter264that communicate with vacuum pump or source145. The gas can be exhausted into the environment or into a containment system. A temperature sensor270(e.g., thermocouple) is shown inFIG.4that is configured for monitoring the temperature of outflow gases.FIG.4further depicts an optional subsystem275which comprises a vacuum source280and solenoid valve285coupled to the controller140B for suctioning steam from a uterine cavity302at an exterior of the dielectric structure150during a treatment interval. As can be understood fromFIG.4, the flow passageway from the uterine cavity302can be through bore120in sleeve110(seeFIGS.2,6and7) or another lumen in a wall of sleeve110can be provided. FIGS.8A-8Dschematically illustrate a method of the invention wherein (i) the thin-wall dielectric structure150is deployed within a patient uterus and (ii) RF current is applied to a contained neutral gas volume in the interior chamber152to contemporaneously create a plasma208in the chamber and capacitively couple current through the thin dielectric wall210to apply ablative energy to the endometrial lining to accomplish global endometrial ablation. More in particular,FIG.8Aillustrates a patient uterus300with uterine cavity302surrounded by endometrium306and myometrium310. The external cervical os312is the opening of the cervix314into the vagina316. The internal os or opening320is a region of the cervical canal that opens to the uterine cavity302.FIG.8Adepicts a first step of a method of the invention wherein the physician has introduced a distal portion of sleeve110into the uterine cavity302. The physician gently can advance the sleeve110until its distal tip contacts the fundus324of the uterus. Prior to insertion of the device, the physician can optionally introduce a sounding instrument into the uterine cavity to determine uterine dimensions, for example from the internal os320to fundus324. FIG.8Billustrates a subsequent step of a method of the invention wherein the physician begins to actuate the first and second handle portions,114aand114b, and the introducer sleeve110retracts in the proximal direction to expose the collapsed frame155and thin-wall structure150within the uterine cavity302. The sleeve110can be retracted to expose a selected axial length of thin-wall dielectric structure150, which can be determined by markings330on sleeve115(seeFIG.1) which indicate the axial travel of sleeve115relative to sleeve170and thus directly related to the length of deployed thin-wall structure150.FIG.2depicts the handle portions114aand114bfully approximated thus deploying the thin-wall structure to its maximum length. InFIG.8B, it can be understood that the spring frame elements158a,158b,160aand160bthe dielectric structure150from a non-expanded position to an expanded position in the uterine cavity as depicted by the profiles in dashed lines. The spring force of the frame155will expand the dielectric structure150until limited by the dimensions of the uterine cavity. FIG.8Cillustrates several subsequent steps of a method of the invention.FIG.8Cfirst depicts the physician continuing to actuate the first and second handle portions,114aand114b, which further actuates the frame155(seeFIGS.5-6) to expand the frame155and thin-wall structure150to a deployed triangular shape to contact the patient's endometrial lining306. The physician can slightly rotate and move the expanding dielectric structure150back and forth as the structure is opened to insure it is opened to the desired extent. In performing this step, the physician can actuate handle portions,114aand114b, a selected degree which causes a select length of travel of sleeve170relative to sleeve115which in turn opens the frame155to a selected degree. The selected actuation of sleeve170relative to sleeve115also controls the length of dielectric structure deployed from sleeve110into the uterine cavity. Thus, the thin-wall structure150can be deployed in the uterine cavity with a selected length, and the spring force of the elements of frame155will open the structure150to a selected triangular shape to contact or engage the endometrium306. In one embodiment, the expandable thin-wall structure150is urged toward and maintained in an open position by the spring force of elements of the frame155. In the embodiment depicted inFIGS.1and2, the handle106includes a locking mechanism with finger-actuated sliders332on either side of the handle that engage a grip-lock element against a notch in housing333coupled to introducer sleeve110(FIG.2) to lock sleeves115and170relative to introducer sleeve110to maintain the thin-wall dielectric structure150in the selected open position. FIG.8Cfurther illustrates the physician expanding the expandable balloon structure225from inflation source148to thus provide an elongated sealing member to seal the cervix314outward from the internal os320. Following deployment of the thin-wall structure150and balloon225in the cervix314, the system100is ready for the application of RF energy to ablate endometrial tissue306.FIG.8Cnext depicts the actuation of the system100, for example, by actuating footswitch235, which commences a flow of neutral gas from source140A into the interior chamber152of the thin-wall dielectric structure150. Contemporaneous with, or after a selected delay, the system's actuation delivers RF energy to the electrode arrangement which includes first polarity electrode215(+) of frame155and the second polarity electrode220(−) which is carried on the surface of expandable balloon member225. The delivery of RF energy delivery will instantly convert the neutral gas in interior chamber152into conductive plasma208which in turn results in capacitive coupling of current through the dielectric wall210of the thin-wall structure150resulting in ohmic heating of the engaged tissue.FIG.8Cschematically illustrates the multiplicity of RF current paths350between the plasma208and the second polarity electrode220through the dielectric wall210. By this method, it has been found that ablation depths of three mm to six mm or more can be accomplished very rapidly, for example in 60 seconds to 120 seconds dependent upon the selected voltage and other operating parameters. In operation, the voltage at which the neutral gas inflow, such as argon, becomes conductive (i.e., converted in part into a plasma) is dependent upon a number of factors controlled by the controllers130B and140B, including the pressure of the neutral gas, the volume of interior chamber152, the flow rate of the gas through the chamber152, the distance between electrode210and interior surfaces of the dielectric wall210, the dielectric constant of the dielectric wall210and the selected voltage applied by the RF source130, all of which can be optimized by experimentation. In one embodiment, the gas flow rate can be in the range of 5 ml/sec to 50 ml/sec. The dielectric wall210can comprise a silicone material having a thickness ranging from a 0.005″ to 0.015 and having a relative permittivity in the range of 3 to 4. The gas can be argon supplied in a pressurized cartridge which is commercially available. Pressure in the interior chamber152of dielectric structure150can be maintained between 14 psia and 15 psia with zero or negative differential pressure between gas inflow source140A and negative pressure or vacuum source145. The controller is configured to maintain the pressure in interior chamber in a range that varies by less than 10% or less than 5% from a target pressure. The RF power source130A can have a frequency of 450 to 550 KHz, and electrical power can be provided within the range of 600 Vrms to about 1200 Vrms and about 0.2 Amps to 0.4 Amps and an effective power of 40 W to 100 W. In one method, the control unit135can be programmed to delivery RF energy for a preselected time interval, for example, between 60 seconds and 120 seconds. One aspect of a treatment method corresponding to the invention consists of ablating endometrial tissue with RF energy to elevate endometrial tissue to a temperature greater than 45 degrees Celsius for a time interval sufficient to ablate tissue to a depth of at least 1 mm. Another aspect of the method of endometrial ablation of consists of applying radiofrequency energy to elevate endometrial tissue to a temperature greater than 45 degrees Celsius without damaging the myometrium. FIG.8Dillustrates a final step of the method wherein the physician deflates the expandable balloon member225and then extends sleeve110distally by actuating the handles114aand114bto collapse frame155and then retracting the assembly from the uterine cavity302. Alternatively, the deployed working end122as shown inFIG.8Ccan be withdrawn in the proximal direction from the uterine cavity wherein the frame155and thin-wall structure150will collapse as it is pulled through the cervix.FIG.8Dshows the completed ablation with the ablated endometrial tissue indicated at360. In another embodiment, the system can include an electrode arrangement in the handle106or within the gas inflow channel to pre-ionize the neutral gas flow before it reaches the interior chamber152. For example, the gas inflow channel can be configured with axially or radially spaced apart opposing polarity electrodes configured to ionize the gas inflow. Such electrodes would be connected in separate circuitry to an RF source. The first and second electrodes215(+) and220(−) described above would operate as described above to provide the current that is capacitively coupled to tissue through the walls of the dielectric structure150. In all other respects, the system and method would function as described above. Now turning toFIGS.9and10, an alternate working end122with thin-wall dielectric structure150is shown. In this embodiment, the thin-wall dielectric structure150is similar to that ofFIGS.5and6except that the second polarity electrode220′ that is exterior of the internal chamber152is disposed on a surface portion370of the thin-wall dielectric structure150. In this embodiment, the second polarity electrode220′ comprises a thin-film conductive material, such as gold, that is bonded to the exterior of thin-wall material210along two lateral sides354of dielectric structure150. It should be appreciated that the second polarity electrode can comprise one or more conductive elements disposed on the exterior of wall material210, and can extend axially, or transversely to axis111and can be singular or multiple elements. In one embodiment shown in more detail inFIG.10, the second polarity electrode220′ can be fixed on another lubricious layer360, such as a polyimide film, for example KAPTON®. The polyimide tape extends about the lateral sides354of the dielectric structure150and provides protection to the wall210when it is advanced from or withdrawn into bore120in sleeve110. In operation, the RF delivery method using the embodiment ofFIGS.9and10is the same as described above, with RF current being capacitively coupled from the plasma208through the wall210and endometrial tissue to the second polarity electrode220′ to cause the ablation. FIG.9further shows an optional temperature sensor390, such as a thermocouple, carried at an exterior of the dielectric structure150. In one method of use, the control unit135can acquire temperature feedback signals from at least one temperature sensor390to modulate or terminate RF energy delivery, or to modulate gas flows within the system. In a related method of the invention, the control unit135can acquire temperature feedback signals from temperature sensor240in interior chamber152(FIG.6to modulate or terminate RF energy delivery or to modulate gas flows within the system. In another aspect of the invention,FIG.11is a graphic representation of an algorithm utilized by the RF source130A and RF controller130B of the system to controllably apply RF energy in an endometrial ablation procedure. In using the expandable dielectric structure150of the invention to apply RF energy in an endometrial ablation procedure as described above, the system is configured to allow the dielectric structure150to open to different expanded dimensions depending on the size and shape of the uterine cavity302. The axial length of dielectric structure150also can be adjusted to have a predetermined axial length extended outward from the introducer sleeve110to match a measured length of a uterine cavity. In any case, the actual surface area of the expanded dielectric structure150within different uterine cavities will differ—and it would be optimal to vary total applied energy to correspond to the differing size uterine cavities. FIG.11represents a method of the invention that automatically determines relevant parameters of the tissue and the size of uterine cavity302to allow for selection of an energy delivery mode that is well suited to control the total applied energy in an ablation procedure. In embodiments, RF energy is applied at constant power for a first time increment, and the following electrical parameters (e.g., voltage, current, power, impedance) are measured during the application of energy during that first time increment. The measured electrical parameters are then used (principally, power and current, V=P/I) to determine a constant voltage to apply to the system for a second time interval. The initial impedance may be also be utilized by the controller as a shutoff criteria for the second treatment interval after a selected increase in impedance. For example, inFIG.11, it can be seen that a first step following the positioning of the dielectric structure in the uterine cavity302is to apply radiofrequency energy in a first mode of predetermined constant power, or constant RF energy (“FIRST MODE-POWER”). This first power is sufficient to capacitively couple current across the dielectric to contacted tissue, wherein empirical studies have shown the power can be in the range of 50 W-300 W, and in one embodiment is 80 W. This first power mode is applied for a predetermined interval which can be less than 15 seconds, 10 seconds, or 5 seconds, as examples, and is depicted inFIG.11as being 2 seconds.FIG.11shows that, in accordance with embodiments, the voltage value is determined a voltage sensor in controller130A and is recorded at the “one-second” time point after the initiation of RF energy delivery. The controller includes a power sensor, voltage sensor and current sensor as is known in the art. This voltage value, or another electrical parameter, may be determined and recorded at any point during the interval, and more than one recording may be made, with averages taken for the multiple recordings, or the multiple recordings may be used in another way to consistently take a measurement of an electrical value or values.FIG.11next illustrates that the controller algorithm switches to a second mode (“SECOND MODE-VOLTAGE”) of applying radiofrequency energy at a selected constant voltage, with the selected constant voltage related to the recorded voltage (or other electrical parameter) at the “one-second” time point. In one embodiment, the selected constant voltage is equal to the recorded voltage, but other algorithms can select a constant voltage that is greater or lesser than the recorded voltage but determined by a factor or algorithm applied to the recorded voltage. As further shown inFIG.11, the algorithm then applies RF energy over a treatment interval to ablate endometrial tissue. During this period, the RF energy is varied as the measured voltage is kept constant. The treatment interval can have an automatic time-out after a predetermined interval of less that 360 seconds, 240 seconds, 180 seconds, 120 seconds or 90 seconds, as examples. By using the initial delivery of RF energy through the dielectric structure150and contacted tissue in the first, initial constant power mode, a voltage level is recorded (e.g., in the example, at one second) that directly relates to a combination of (i) the surface area of the dielectric structure, and the degree to which wall portions of the dielectric structure have been elastically stretched; (ii) the flow rate of neutral gas through the dielectric structure and (iii) the impedance of the contacted tissue. By then selecting a constant voltage for the second, constant voltage mode that is directly related to the recorded voltage from the first time interval, the length of the second, treatment interval can be the same for all different dimension uterine cavities and will result in substantially the same ablation depth, since the constant voltage maintained during the second interval will result in power that drifts off to lower levels toward the end of the treatment interval as tissue impedance increases. As described above, the controller130A also can use an impedance level or a selected increase in impedance to terminate the treatment interval. The algorithm above provides a recorded voltage at set time point in the first mode of RF energy application, but another embodiment can utilize a recorded voltage parameter that can be an average voltage over a measuring interval or the like. Also, the constant voltage in the second mode of RF energy application can include any ramp-up or ramp-down in voltage based on the recorded voltage parameter. In general, an electrosurgical method for endometrial ablation comprises positioning a RF ablation device in contact with endometrial tissue, applying radiofrequency energy in a first mode based on a predetermined constant power over a first interval, and applying radiofrequency energy in a second mode over a second interval to ablate endometrial tissue, the energy level of the second mode being based on treatment voltage parameters obtained or measured during the first interval. Power during the first interval is constant, and during the second period is varied to maintain voltage at a constant level. Another step in applying RF energy in the first mode includes the step of recording a voltage parameter in the first interval, wherein the voltage parameter is at least one of voltage at a point in time, average voltage over a time interval, and a change or rate of change of voltage. The second mode includes setting the treatment voltage parameters in relation to the voltage parameter recorded in the first interval. Referring toFIG.11, it can be understood that an electrosurgical system for endometrial ablation comprises a radiofrequency ablation device coupled to an radiofrequency power supply, and control means connected to the radiofrequency power supply for switching the application of radiofrequency energy between a constant power mode and a constant voltage mode. The control means includes an algorithm that (i) applies radiofrequency energy in the first mode (ii) records the voltage within a predetermined interval of the first mode, and (iii) applies radiofrequency energy in the second mode with constant voltage related to the recorded voltage. In another aspect, the invention comprises a radiofrequency power supply, a means for coupling the radiofrequency power supply to an ablation device configured for positioning in a uterine cavity, the ablation device comprising a dielectric for contacting endometrial tissue, a system for recording an electrical parameter of the ablation device and contacted tissue, and a feedback system for varying the application of radiofrequency energy to tissue between a constant power mode and a constant voltage mode based on a recorded electrical parameter. In another embodiment of the invention,FIGS.12,13A and13Bdepict components of the ablation device ofFIGS.1-2that provide the physician with an indication of the degree to which the dielectric structure150has opened in the patient's uterine cavity302. It can be understood fromFIGS.5,6and8Cthat the spring frame155that moves the dielectric structure150from a contracted, linear shape (FIG.8B) to an expanded, triangular shape (FIG.8C) results from actuating the handle106to move the assembly of inner sleeve170, intermediate sleeve115, frame155and dielectric structure150distally relative to the introducer sleeve110to thus expose and deploy the dielectric structure150in the uterine cavity302. Referring toFIG.12, it can be seen that inner sleeve170and intermediate sleeve115are shown for convenience without their respective welded connections to spring frame elements158a,158b,160aand160b. The frame elements158a,158b,160aand160band their springing function can be seen inFIGS.5and6. InFIG.12, the introducer sheath110is shown as being moved proximally relative to the dielectric structure150which corresponds to a position of the dielectric structure150shown inFIG.8B. In the schematic view ofFIG.12, the distal end400of sleeve170has an axial position X and can be approximately the same axial position as the distal end402of the introducer sleeve110. It can be understood that when the dielectric structure150and interior spring frame155are deployed in a uterine cavity, the spring force of frame155will tend to open the dielectric structure150from a position inFIG.8Btoward the position ofFIG.8C. InFIG.12, an initial position of the distal end405of sleeve170has an axial position indicated at A which corresponds to plan shape A′ of the dielectric structure150. In a typical procedure, the spring force of frame155will move the distal end405of sleeve170toward an axial position B which corresponds to expanded dielectric plan shape B′ or toward an axial position C and corresponding expanded dielectric plan shape C′. Dielectric plan C′ represents a fully expanded dielectric structure150. In order to allow the spring force of frame155to expand the frame and dielectric structure150, the physician may gently and very slightly rotate, tilt and translate the expanding dielectric structure150in the uterine cavity302. After thus deploying the dielectric structure, the different dimensions of uterine cavities will impinge on the degree of expansion of the dielectric structure150—and the size and surface area of the dielectric structure, as an example, will be within the dimension range between plan shapes A′ and plan shape C′ ofFIG.12. In one aspect of the invention, it is important for the system and physician to understand the degree to which the dielectric structure150and frame155has expanded in the uterine cavity. If the dielectric structure155has not expanded to a significant degree, it may indicate that the uterine cavity is very small or very narrow, that fibroids are impinging on dielectric structure preventing its expansion, that the uterine cavity is very asymmetric, or that a tip of the dielectric structure and frame155has penetrated into an endometrial layer, perforated the uterine wall or followed a dissection path created by a sounding procedure just prior to deployment of the dielectric structure. Further, in one system embodiment, the dielectric structure150is preferred to have a minimum surface area directly related to its expanded shape to thus cooperate with an RF energy delivery algorithm. In one embodiment, the system provides a “degree of frame-open” signaling mechanism for signaling the physician that the frame155and dielectric structure150has expanded to a minimum predetermined configuration. The signaling mechanism is based on the relative axial location of inner sleeve170and sleeve115as can be understood fromFIGS.12and13A-13B. InFIGS.1and2, it can be seen that a sliding element450is exposed in a top portion of handle component114B to slide axially in a slot452. In a schematic view of handle component114binFIGS.13A-13B, it can be seen that the proximal end454of sleeve115is fixed in handle component114b. Further, the proximal end of456of the inner sleeve170is connected to the sliding element450that slides in slot452. Thus, it can be understood that inner sleeve170is slidable and free-floating in the bore175of sleeve115and can be moved axially to and fro depending to the opening spring force of frame155—which force can be constrained by the frame being withdrawn into the bore120of introducer sleeve110or by uterine walls impinging on the dielectric structure150and frame155when deployed in a uterine cavity. As can be seen inFIGS.1,2,13A and13B, the sliding element has at least two axially-extending indicators460A and460B that can be different colors that slide axially relative to status-indicating arrow element465in a fixed location in the handle114b. In one embodiment, indicator460A can be red for “stop” and indicator460B can be “green”, for indicating whether to stop proceeding with the procedure, or to go ahead with the ablation procedure. InFIG.13A, it can be seen that inner sleeve170and its distal end405are only axially extended at point A which corresponds to dielectric expansion profile A′. The limited expansion of dielectric structure at profile A′ is indicated at the slider450wherein the arrow465points to the red ‘stop” indicator460A which indicates to the physician to stop and not proceed with the ablation procedure due to limited expansion of dielectric structure150. FIG.13Bdepicts an extension of inner sleeve170and its distal end405to axially extended at point B which corresponds to dielectric expansion profile B′. This intermediate expansion of dielectric structure150at profile B′ is indicated to the physician by observing slider450wherein arrow465points to the green indicator460B which indicates “go”—that is, the physician can proceed with the ablation procedure since the dielectric structure150and frame155have expanded to a predetermined degree that cooperates with an RF energy delivery algorithm. It can be understood fromFIG.13Bthat sleeve170can move axially toward extended position C with corresponding dielectric structure profile C′ and indicator arrow465will again point to the “go” portion460B of sliding element which is green. In another aspect of the invention also depicted inFIGS.13A-13B, the handle component114bcan include a electrical contact sensor470that detects the axial movement of sliding element450and sleeve170relative to sleeve115to thereby provide an electronic signal indicating the degree of expansion of the frame155and dielectric structure150. In one embodiment, the electronic signal communicates with RF controller130B to disable the system if the relative axial positions of sleeves170and115do not indicate a predetermined degree of expansion of the frame155and dielectric structure. The system can further include an override mechanism, whereby the physician can manipulate the instrument slightly back and forth and rotationally to evaluate whether the frame155opens incrementally more. In another embodiment, the electrical sensor470can detect a plurality of degrees of expansion of the frame155and dielectric structure150, for example as depicted by an electrical contact be activated at positions AA, BB, CC, and DD of the slider450inFIGS.13A-13B, wherein each degree of expansion of frame155signals the controller to select a different RF delivery algorithm. The various different RF delivery algorithms can alter at least one of: (i) the duration of a treatment interval, for example from between 60 seconds and 240 seconds, (ii) the relation between a recorded voltage and a treatment voltage as described in the text accompanyingFIG.11above (e.g., the treatment voltage can equal the recorded voltage, or vary as a factor about 0.8, 0.9, 1.0, 1.1 or 1.2 times the recorded voltage; (iv) can vary a ramp-up or ramp-down in voltage, or can a time interval of the first and second modes of RF energy delivery described above. The number of degrees of expansion of frame155and dielectric structure can range from 1 to 10 or more. The embodiment ofFIGS.1,2,13A and13Bdepict indicator subsystems that include visual and electrical signals, but it should be appreciated that the indicator subsystem can provide any single or combination signals that can be visual, aural or tactile with respect to the operator and/or electrically communicate with microprocessors, programmable logic devices or controllers of the ablation system. Although particular embodiments of the present invention have been described above in detail, it will be understood that this description is merely for purposes of illustration and the above description of the invention is not exhaustive. Specific features of the invention are shown in some drawings and not in others, and this is for convenience only and any feature may be combined with another in accordance with the invention. A number of variations and alternatives will be apparent to one having ordinary skills in the art. Such alternatives and variations are intended to be included within the scope of the claims. Particular features that are presented in dependent claims can be combined and fall within the scope of the invention. The invention also encompasses embodiments as if dependent claims were alternatively written in a multiple dependent claim format with reference to other independent claims.

11857249

DETAILED DESCRIPTION The present technology is generally directed to devices, systems, and methods for monitoring and/or controlling deployment of a neuromodulation element within a body lumen and related technology. Among other contexts, the present technology can be useful in the context of electrically- and/or thermally-induced renal neuromodulation, which is described in detail below. In at least some embodiments, one or more pre-neuromodulation parameters are measured and analyzed to evaluate electrode contact, to customize power delivery via an electrode, and/or for another suitable purpose. Impedance through an electrical circuit at a treatment site is one example of a potentially useful parameter. Impedance or another suitable monitored parameter can be analyzed based on defined criteria. Based on this analysis, one or more aspects of a neuromodulation treatment may be controlled, customized, or otherwise modified to enhance the treatment. Methods in accordance with at least some embodiments of the present technology allow for enhanced verification of adequate deployment of a neuromodulation element at a treatment site (e.g., adequate contact between an electrode of a neuromodulation element and tissue at a treatment site) prior to initiating energy delivery. This can be a significant advantage over conventional counterparts. For example, with at least some conventional neuromodulation systems, inadequate deployment of a neuromodulation element can only be detected after energy delivery has been initiated, such as by recognizing a less than expected increase in temperature at a treatment site. This approach is suboptimal at least because it can be difficult to account for partial treatment, if any, that occurred before inadequate deployment of a neuromodulation element is recognized. Methods in accordance with at least some embodiments of the present technology include using impedance for the purpose of detecting inadequate deployment of a neuromodulation element. In a particular embodiment, a method includes advancing a catheter including an elongate shaft and a neuromodulation element operably connected to the shaft toward a treatment location within a body lumen of a human patient. The neuromodulation element can include an elongate electrode slidably disposed within a dielectric sleeve. After advancing the catheter, the neuromodulation element can be deployed at the treatment location. In one embodiment, deployment of the neuromodulation element can include a first deployment phase during which an electrode of the neuromodulation element moves radially outward while a first interface area between the electrode and the dielectric sleeve decreases and a second interface area between the electrode and a biological fluid (e.g. blood) at the treatment location increases. The first deployment phase can be followed by a second deployment phase during which the first interface decreases and a third interface area between the electrode and a lumen wall at the treatment location increases. The second deployment phase can be followed by a third deployment phase during which the electrode moves radially outward and the third interface area is more stable than it is during the second deployment phase. While deploying the neuromodulation element, the electrode can measure an electrical property of a sum of material adjacent to the electrode. The sum of material adjacent to the electrode can include portions of the dielectric sleeve, the lumen wall and the biological fluid adjacent to the electrode. The method can further include detecting a transition of the electrical property corresponding to a transition from the first deployment phase to the second deployment phase and generating a status indication, enabling a neuromodulation treatment, or both in response to detecting the transition of the electrical property. As an additional or alternative advantage, methods in accordance with at least some embodiments of the present technology allow a transverse cross-sectional dimension (e.g., diameter) at a treatment site to be determined prior to initiating energy delivery. This can be useful to allow subsequent energy delivery to be customized according to the determined dimension. For example, a treatment carried out in a small blood vessel may call for less energy to be delivered relative to a treatment carried out in a larger blood vessel. In a particular embodiment, methods include advancing a catheter including an elongate shaft and a neuromodulation element operably connected to the shaft toward a treatment location within a body lumen of a human patient. The neuromodulation element can include an elongate electrode slidably disposed within a dielectric sleeve. The elongate control member can be moved relative to the shaft and/or the shaft can be moved relative to the control member so as to cause a longitudinal shift between the control member and the shaft. The longitudinal shift can cause the electrode to move radially outward while a wall-interface area between the electrode and a lumen wall at the treatment location increases. While moving the control member, the longitudinal shift can be measured. While the electrode moves radially outward, an electrical property of a sum of material adjacent to the electrode can be measured. The sum of material adjacent to the electrode can include portions of the dielectric sleeve, the lumen wall and the biological fluid adjacent to the electrode. The method can further include detecting a transition of the electrical property corresponding to a stabilization of the wall-interface area. E.g., physical stability of the electrode with respect to the lumen wall causes the size of the wall-interface area to become constant or nearly so, as detected by the measured electrical property. Energy may be delivered to one or more nerves of the patient via the electrode according to a profile of energy over time. The profile of energy can be based on the longitudinal shift at the time of the transition of the electrical property, and the longitudinal shift at the time of the transition of the electrical property can correspond to a diameter of the body lumen. Specific details of several embodiments of the present technology are described herein with reference toFIGS.1-10. Although many of the embodiments are described herein with respect to devices, systems, and methods for modulation of renal nerves using electrodes, other applications and other treatment modalities in addition to those described herein are within the scope of the present technology. Additionally, other embodiments of the present technology can have different configurations, components, or procedures than those described herein. For example, other embodiments can include additional elements and features beyond those described herein or be without several of the elements and features shown and described herein. For ease of reference, throughout this disclosure identical reference numbers are used to identify similar or analogous components or features, but the use of the same reference number does not imply that the parts should be construed to be identical. Indeed, in many examples described herein, the identically-numbered parts are distinct in structure and/or function. As used herein, the terms “distal” and “proximal” define a position or direction with respect to the treating clinician or clinician's control device (e.g., a handle assembly). “Distal” or “distally” can refer to a position distant from or in a direction away from the clinician or clinician's control device. “Proximal” and “proximally” can refer to a position near or in a direction toward the clinician or clinician's control device. The term “area” as used herein with respect to an electrode refers to a surface area and can refer to a size of a particular surface area, e.g. “fluid-interface area” of an electrode. Selected Examples of Neuromodulation Systems FIG.1illustrates a neuromodulation system10(“system10”) configured in accordance with an embodiment of the present technology. The system10can include a neuromodulation catheter12operably coupled to a console26. The catheter12can include an elongate shaft16having a proximal portion18, and a distal portion20. The catheter12can further include a neuromodulation element21at the distal portion20of the shaft16, and a handle34at the proximal portion18of the shaft16. The neuromodulation element21can include a support member24and one or more wire electrodes202,204wrapped in a helical/spiral configuration around the support member24. It will be appreciated that although two electrodes202,204are shown, the neuromodulation element21can include more or fewer than two electrodes. The proximal end of the therapeutic assembly21is carried by or affixed to the distal portion20of the elongate shaft16. A distal end of the therapeutic assembly21may terminate with, for example, an atraumatic rounded tip or cap (e.g., cover129inFIG.5C). Alternatively, the distal end of the therapeutic assembly21may be configured to engage another element of the system10or treatment device12. For example, the distal end of the therapeutic assembly21may define a passageway for engaging a guide wire (not shown) for delivery of the treatment device using over-the-wire (“OTW”) or rapid exchange (“RX”) techniques. The energy source or console26can be configured to generate a selected form and/or magnitude of energy for delivery to a target treatment site via the electrodes202,204. For example, the console26can include an energy generator configured to generate radio frequency (RF) energy, pulsed energy, microwave energy, optical energy, ultrasound energy (e.g., intravascularly delivered ultrasound, extracorporeal ultrasound, high-intensity focused ultrasound (HIFU)), direct heat energy, radiation (e.g., infrared, visible, gamma), or another suitable type of energy. In a particular embodiment, the console26includes an RF generator operably coupled to the electrodes202,204. The console26can be configured to control, monitor, supply, or otherwise support operation of the catheter12. A control mechanism, such as a foot pedal32, may be connected (e.g., pneumatically connected or electrically connected) to the console26to allow an operator to initiate, terminate and/or adjust various operational characteristics of the energy generator, such as power delivery. The energy console26can be electrically coupled to the neuromodulation (treatment) device12via a cable28. At least one supply wire (not shown) passes along the elongated shaft16or through a lumen in the elongated shaft16to the one or more wire electrodes202,204and transmits the treatment energy to the one or more wire electrodes202,204. In some embodiments, each helical push wire electrode202,204includes its own supply wire which would allow for each helical push wire electrode202,204to be independently energized in a sequential or exclusive manner. In other embodiments, however, the wire electrodes202,204may be electrically coupled to the same supply wire. The supply wire may be used as a thermocouple wire and may be used to transmit temperature and impedance measurements taken at the distal cap. The console26can be configured to deliver neuromodulation energy according to one or more automated control algorithms30and/or manually under the control of a clinician. The control algorithms30can be executed using a processor (not shown) of the system10to control the delivery of power to the neuromodulation element21. In some embodiments, selection of a control algorithm30for a particular patient may be guided by one or more diagnostic algorithms33that include measuring and evaluating one or more parameters prior to energy delivery. For example, the diagnostic algorithms33can provide patient-specific feedback to a clinician who can use the feedback to select an appropriate control algorithm30and/or to modify a previously selected control algorithm30. Further details regarding control algorithms30are described below with reference toFIG.10. Further details regarding diagnostic algorithms33are described below with reference toFIGS.4and6-9. The electrodes202,204may be configured to deliver power independently (e.g., in a monopolar fashion) simultaneously, selectively, and/or sequentially. Alternatively or in addition, the electrodes202,204may be configured to deliver power collectively (e.g., in a bipolar fashion). In monopolar embodiments, a neutral or dispersive electrode38may be electrically connected to the console26and attached to the exterior of a patient. Furthermore, a clinician may optionally choose which electrodes202,204are used for power delivery in order to form highly customized lesion(s) having a variety of shapes or patterns. The system10can further include a controller42having, for example, memory (not shown), storage devices (e.g., disk drives), one or more output devices (e.g., a display), one or more input devices (e.g., a keyboard, a touchscreen, etc.) and processing circuitry (not shown). The output devices may be configured to transmit signals to the catheter12(e.g., via the connector28) to control power to the electrodes202,204. In some embodiments the output devices can be configured to obtain signals from the electrodes202,204and/or any sensors associated with the catheter12, such as a pressure sensor, temperature sensor, impedance sensor, flow sensor, chemical sensor, ultrasound sensor, optical sensor, or another suitable sensing device. The sensors (not shown) may be located proximate to or within the helical push wire electrodes22and connected to one or more supply wires (not shown). For example, a total of two supply wires may be included, in which both wires could transmit the signal from the sensor and one wire could serve dual purpose and also convey the energy to the helical push wire electrodes22. Alternatively, a different number of supply wires may be used to transmit energy to the helical push wire electrodes22. The indicator40of the system10can serve as an output device and may be a standalone device or may alternatively be associated with the console26and/or the handle34. The indicator40can include one or more LEDs, a device configured to produce an audible indication, a display screen, and/or other suitable communicative devices. In some embodiments, the indicator40is interactive. For example, the indicator40can include a user interface that can receive user input and/or provide information to a user. As another example, the indicator40can include processing circuitry for monitoring the one or more sensors. Display devices may be configured to provide indications of power levels or sensor data, such as audio, visual or other indications, or may be configured to communicate the information to another device. In some embodiments, the controller42is part of the console26, as shown inFIG.1. Additionally or alternatively, the controller42can be personal computer(s), server computer(s), handheld or laptop device(s), multiprocessor system(s), microprocessor-based system(s), programmable consumer electronic(s), digital camera(s), network PC(s), minicomputer(s), mainframe computer(s), and/or any suitable computing environment. The memory and storage devices can be computer-readable storage media that may be encoded with non-transitory, computer-executable instructions (e.g., corresponding to the control algorithm(s)30, the feedback algorithm(s)33, etc.). In addition, the instructions, data structures, and message structures may be stored or transmitted via a data transmission medium, such as a signal on a communications link and may be encrypted. Various communications links may be used, such as the Internet, a local area network, a wide area network, a point-to-point dial-up connection, a cell phone network, Bluetooth, RFID, and other suitable communication channels. Some aspects of the system10may be described herein in the general context of computer-executable instructions, such as program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, and so on that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or distributed as desired in various embodiments. Selected Examples of Neuromodulation Elements and Methods FIG.2Ais an enlarged side view of the neuromodulation element21in a delivery state. As shown inFIG.2A, the support member24of the neuromodulation element21can be at least partially positioned within a central lumen of the shaft16and have a portion that extends distally from an opening at the distal end of the shaft16. The first and second electrodes202,204can have proximal ends (not shown) coupled to a proximal portion of the catheter12(e.g., at the handle34) and distal ends coupled to a distal portion of the support member24. A proximal portion of each of the first and second electrodes202,204can be surrounded by first and second proximal sleeves212b,214b, respectively, and a distal portion of each of the first and second electrodes202,204can be surrounded by first and second distal sleeves212a,214a, respectively. A segment of each of the electrodes202,204can be exposed (e.g., not surrounded by the sleeves and/or any other structure of the catheter12) between the proximal212b,214band distal212a,214asleeves. The sleeves212a-b,214a-bcan be sufficiently flexible to allow the electrodes202,204to radially expand and/or collapse onto the support member24yet stiff enough to provide control of the exit and/or entry angles of the electrodes202,204. FIG.2Bis an enlarged side view of the neuromodulation element21in a treatment state having a shape wherein electrodes202and204are helically/spirally intertwined. In the embodiment illustrated inFIG.2Awherein the neuromodulation element21is in a delivery state, electrodes202and204may also be helically/spirally intertwined, although other arrangements are possible. To transform the neuromodulation element21from the delivery state shown inFIG.2Ato the treatment state shown inFIG.2B, the proximal ends of the electrodes202,204can be pushed distally, thereby causing a distal portion of the electrodes202,204to radially expand. As the electrodes202,204radially expand, the segments201of the electrodes202,204between the proximal212b,214band distal212a,214asleeves can increase. For example, as shown inFIG.2A, when the neuromodulation element21is in the delivery state, the segments201of the electrodes202,204between the proximal212b,214band distal212a,214asleeves may be relatively small. As shown inFIG.2B, when the neuromodulation element21is in the treatment state, the segments201of the electrodes202,204between the proximal212b,214band distal212a,214asleeves may be significantly larger. Thus, moving the neuromodulation element21from the delivery state to the treatment state can increase the size of therapeutically active segments of the electrodes202,204. Moreover, when the neuromodulation element21is in the treatment state, the electrodes can have a shape well suited for making stable contact with an inner wall of a lumen within which the neuromodulation element21is disposed. For example, such a lumen can have an uncertain and potentially varying diameter that the neuromodulation element21resiliently accommodates. FIG.3Ais an enlarged anatomical side view of the neuromodulation element21and associated components in a delivery state being positioned at a treatment location within a renal artery RA that extends between an aorta AT and a kidney K in a human patient. The neuromodulation element21can also be used for other purposes and at treatment locations within other suitable body lumens. To locate the neuromodulation element21at the treatment location, the catheter12can be advanced toward the treatment location while the neuromodulation element21is radially constrained in the low-profile delivery state, as shown inFIG.3A. The shaft16may be guided, simultaneously or separately, from a vascular puncture site (not shown) to renal artery RA using a guiding catheter and/or a guide wire, which is omitted fromFIG.3Afor simplicity of illustration. As shown inFIG.3A, when the neuromodulation element21is in the delivery state, at least a portion of the segment201of each of the electrodes202,204between the proximal212b,214band distal212a,214asleeves may be exposed to the interior of the renal artery RA. As such, at least a portion of each of the segments201defines a fluid-interface area that is in contact with a biological fluid (e.g., blood) present in the renal artery RA at the treatment site. Once the neuromodulation element21is adequately positioned at the treatment site, the proximal ends of the electrodes202,204can be pushed distally to begin transformation of the neuromodulation element21from its delivery state to its treatment state. As the electrodes202,204radially expand, the segments201lengthen. As such, at least before the electrodes202,204contact the wall W of the renal artery RA, while the electrodes202,204expand, the fluid-interface area of each of the electrodes202,204increases and a sleeve-interface area of the electrode (e.g., the portion of the electrode surrounded by the sleeves212a-b,214a-b) decreases. At some point during deployment, the electrodes202,204can begin to contact an inner surface S of the wall W of the renal artery RA. As this occurs, portions of each of the segments201previously in contact with biological fluid may instead begin to contact the wall W. Accordingly, a wall-interface area (i.e., the portion of each of the electrodes202,204in contact with the wall W) may increase as the electrodes202,204continue to expand and additional portions of the electrodes202,204engage the wall W. Depending on the rate at which the segments201are lengthening and the rate at which the wall-interface area increases, the fluid-interface area and/or the sleeve-interface area of each of the electrodes202,204can increase, decrease, and/or remain the same as the wall-interface area of each of the electrodes202,204increases. For example, since the electrodes may still be expanding when first making contact with the wall W, if the rate at which the electrodes are expanding (and thus exposing additional portions of the electrodes) is greater than the rate at which the wall-interface area increases (rate at which additional portions of the electrodes contact the wall W), then the fluid-interface area may still be increasing. Expansion of the electrodes202,204can end once the electrodes202,204are in stable apposition with an inner surface S of a wall W of the renal artery RA, as shown inFIG.3B. At this stage of deployment, the segments201are no longer increasing in length, and thus both the wall-interface areas, the sleeve-interface areas, and the fluid-interface areas of the electrodes202,204remain generally constant. At this time, one or both of the electrodes202,204can be energized to modulate one or more nerves at or near the treatment location. Before treatment begins, one or more of the diagnostic algorithms33can be used to monitor one or more operating parameters. Such operating parameters detected by the diagnostic algorithm(s)33include electrical properties (e.g., impedance, voltage, current, power, etc.), temperature, and/or blood flow parameters as compared to accepted or expected thresholds and/or predetermined or calculated ranges. For example, predetermined operating parameter thresholds and/or ranges can be empirically determined to create a look-up table. The look-up table may provide operating parameter thresholds and/or ranges for corresponding operating threshold values. Look-up table values can be empirically determined, for example, based on clinical studies. Impedance is one example of an operating parameter that can be advantageous to monitor for several diagnostic reasons, one of which is to inform the clinician as to the existence and/or degree of contact between one or more of the electrode(s) and the lumen wall at the treatment location. For example,FIG.4shows a graph of impedance measurements versus time as the neuromodulation element21is delivered and deployed within the lumen. Generally, the measured impedance can be a function of the sum of material adjacent the electrode (e.g., portions of the sleeves212a-b,214a-b, portions of the lumen wall, the biological fluid adjacent to the electrode, etc.). InFIG.4, time t=0 represents a point during delivery/deployment where the neuromodulation element21is located within the lumen at the treatment location in a delivery state (such as that shown inFIG.3A). In the delivery state, only a small portion of each of the electrode(s)202,204is exposed to biological fluid between the proximal212b,214band distal212a,214asleeves, and thus the fluid-interface area for each electrode is relatively low. Because most of the length of the electrode is surrounded by the sleeves212a-b,214a-bor other various components of the catheter12, the measured impedance is relatively high before deployment begins. During a first deployment phase (labeled as “Phase I” inFIG.4), the electrodes202,204begin to radially expand and the sleeve-interface area decreases. As shown inFIG.4, during Phase I the measured impedance decreases. This occurs because the impedance of biological fluids tends to be less than that of the sleeves212a-b,214a-band/or other components of the catheter12that may be in contact with the electrodes202,204prior to deployment. In another aspect, it can be advantageous to monitor and/or the detect Phase I to evaluate whether or not the electrodes202,204are expanding properly. For example, if one or both electrodes202,204do not deploy properly, the expected impedance decrease would not be reflected in Phase I. As a result, the diagnostic algorithm of the present technology can be configured to identify the generally constant impedance in Phase I and generate a signal to alert the user. During a second deployment phase (labeled as “Phase II” inFIG.4), the electrodes202,204begin to contact the lumen wall and impedance measurements increase. This increase in impedance is a result of portions of the fluid-interface area being replaced by wall-interface areas. Lumen walls typically have a higher impedance than biological fluids, and as a result, the measured impedance (which can be a function of the sum of material adjacent the electrode) increases. As shown inFIG.4, a third deployment phase (labeled as “Phase III”) begins when the electrodes202,204have full (or partial) tissue contact with the lumen wall (or in other words, the electrodes202,204have either slowed or stopped expanding) and the wall-interface areas stabilize. As such, the impedance measurements during the third deployment phase may remain generally constant (e.g., not fluctuating beyond about 5 ohms). It will be appreciated that more or less than three deployment phases are within the scope of the present technology, and the terms “first,” “second,” and “third” are used only for ease of reference. Moreover, although the graphs shown inFIG.4illustrate “increasing” and “decreasing” impedance parabolically and linearly, respectively, impedance measurements can rise and fall along any suitable curve (e.g., exponentially, parabolically, step-wise, other non-linear methods, etc.). FIG.5Ais an enlarged side view of another embodiment of a neuromodulation element621in a delivery state. The neuromodulation element621can generally relate to the neuromodulation element21shown inFIG.2A, except the first and second electrodes602,604of the neuromodulation element621ofFIG.5Ainclude first and second insulated portions603,605, respectively (shown in dashed lines). The first and second insulated portions603,605can be at least partially surrounded by (or coated with) an insulation material. As shown inFIG.5A, in the delivery state, the distal portions of the first and second insulated portions603,605can be surrounded by the first and second proximal sleeves612b,614b, respectively, such that the insulated portions603,605, do not extend distally beyond the distal ends of their respective sleeves. As such, in the delivery state, the segments601of the first and second electrodes602,604between the proximal612b,614band distal612a,614asleeves can be defined by a treatment portion609(i.e., the portion of the first and second electrodes602,604configured to deliver energy to the lumen wall). In other embodiments (not shown), a portion of the first and/or second insulated portions603,605can extend beyond the sleeve in the delivery state. FIG.5Bis an enlarged side view of the neuromodulation element621in a treatment state. As illustrated byFIG.5B, as the electrodes602,604radially expand, the first and second insulated portions603,605are pushed distally and a distal portion603′,605′ of each extends beyond the distal ends of the proximal sleeves612b,614b. As such, in the treatment state, the segments601of the first and second electrodes602,604between the proximal612b,614band distal612a,614asleeves includes a distal portion603′,605′ of the first and second insulated portions603,605and the treatment portions609. Accordingly, although the length of the segment601between the proximal612b,614band distal612a,614asleeves increases when the neuromodulation element621moves from the delivery state to the treatment state, the treatment portions609of the electrodes602,604can remain generally the same length. Thus, unlike the neuromodulation element21ofFIGS.2A-2B, moving the neuromodulation element621from the delivery state to the treatment state generally does not increase the size of the treatment portions609of the first and second electrodes602,604. FIG.5Cis a perspective view of a treatment device112comprising helical push wire electrodes in a delivery state (e.g., low-profile or collapsed configuration) outside of a patient in accordance with an embodiment of the present technology, andFIG.5Dis a perspective view of the treatment device112comprising helical push wire electrodes in a deployed state (e.g., expanded configuration). Referring toFIGS.5C and5D, the distal electrode support structure122comprises a tubular member having a central lumen to define a longitudinal axis B-B. In one embodiment, the cross sectional shape of the distal electrode support structure122can be a square cross section which may create a smaller profile allowing use with a smaller diameter catheter. In one embodiment, a portion of the distal support structure122is square and a portion of the distal support structure122is rounded. In another embodiment, the entire distal support structure122is square. The illustrated treatment device comprises a shaft125, one or more helical push wire electrodes123, a distal electrode support section122, and thermocouple wires124. The shaft125is mounted to the distal electrode support section122. A joint may be provided to couple the distal electrode support section122to the shaft125, thereby providing the desired transfer of torque from the shaft125to the electrode support section122when navigating to the treatment site. More specifically, each end of the electrode support section122and the shaft125may respectively include mating notches that permit the ends of the tubular members to interlock. In some embodiments, disposed about the joint is a stainless steel sleeve that is crimped about the juncture to provide additional support to the joint. In various embodiments, the shaft125is fixed to the distal electrode support section122by adhesive, welding, crimping, over-molding, and/or soldering. The shaft125and the distal electrode support section122may together define a lumen where the thermocouple wires124are disposed. The thermocouple wires124are disposed along or in parallel to the longitudinal axis B-B. In one embodiment, the thermocouple wires124may be fixed to the proximal end122aof the distal electrode support section122. In another embodiment, the thermocouple wires124may be fixed to the distal end122bof the distal electrode support section122. In further embodiments, the helical push wire electrodes123may be coupled to the thermocouple wires124at the distal end122bof the distal electrode support section122. The helical push wire electrodes123and the thermocouple wires124may be coupled by soldering or by a mechanical lock. In one embodiment, the therapeutic assembly may comprise a cover129encasing the joint of the helical push wire electrodes and the thermocouple wires. The cover129may be made of various materials. In one embodiment, the cover129may be coated with Titanium Nitride (TiN). In further embodiments, the therapeutic assembly may comprise a temperature sensor, such as a thermometer. In one embodiment, the cover129encloses the temperature sensor. The cover129could also be used to electrically connect the supply wire to multiple wire electrodes (such as electrode123). Accordingly, the same supply wire would also transmit temperature and impedance measurements. In embodiments having only a single electrode (not shown), the same supply wire may act as a TC wire which can transmit temperature and impedance. Further, as illustrated inFIG.5D, the proximal sleeves127and the distal sleeves128may provide complete or near complete insulation of electrodes123when the therapeutic assembly is in the delivery configuration with helical push wire electrodes. Accordingly, the impedance of the deployed electrodes is reduced and more RF energy is delivered. In the illustrated example, the proximal sleeves127and the distal sleeves128, or the proximal sleeves127and the distal coating or lamination on the electrode123have a space between them in the collapsed configuration. In other embodiments, the sleeves127and128, or the proximal sleeves127and the distal coating may make contact or even overlap, that is, the distal sleeve128or lamination or coating may axially telescope within the lumen of the proximal sleeve127. In the illustrated example, the electrodes123are round wires. In other embodiments, the electrodes123may be flat wires or wires of other geometries as previously described. In the case of flat wires, the electrodes123can be positioned such that when deployed, the flat surface is in contact with the inner wall of the renal artery. The fixed distal end123bof the electrodes, the proximal sleeves127and the distal sleeves128may prevent the flat-wire electrodes from rotating and may ensure that the flat surface is in contact with the inner wall of the renal artery when the electrodes are deployed. FIG.5Eillustrates an exemplary therapeutic assembly comprising push wire electrodes550and551. In this embodiment, a separate TC/supply wire pair552a-b,553a-bis coupled to each push wire electrode550,551respectively. In this manner, separate temperature measurements may be obtained and each push wire electrode550may be energized independently. One push wire electrode550coupled with TC/supply wire pair552a-bwill be described but it should be understood that this same configuration could apply to the other push wire electrode551(or any other push wire electrode550for an embodiment with a plurality of push wire electrodes). The TC/supply wire pair552a-bmay run from the proximal end of the treatment device12(shown inFIG.1) through a lumen in the elongated shaft16through a central lumen of the distal electrode support section24out the push wire electrode's distal exit port554. The TC/supply wire pair552a-bruns along the push wire electrode550itself being routed across the inner (non-tissue contact) surface of the push wire electrode550. The TC/supply wire pair552a-bcan be fixed to the push wire electrode550at an attachment point557near the end of the distal sleeve26a. Alternatively, the TC/supply wire pair552a-bcan be routed within a lumen of the distal sleeve26aand fixed to the distal sleeve26aitself at its end (i.e. exit port of the push wire electrode550). The distal tip556of the push wire electrode550could be covered with adhesive555which protects the distal tip, configures the distal tip to be atraumatic, as well as secures the TC/supply wires552a-binto place. As with previous embodiments, the TC/supply wire pair552a-bcould act as a wire to provide temperature and impedance measurements as well as supply RF energy. Alternatively, RF energy could be supplied to the distal tip with a separate RF supply wire and within the lumen of the catheter, provided the RF supply wire is electrically coupled to the push wire electrode550. In an alternative embodiment (not shown), a single TC/supply wire could be provided for a plurality of push wire electrodes. In this embodiment, the push wire electrodes would be electrically coupled within the distal tip thus energizing all push wire electrodes simultaneously. The distal point of attachment of the TC/supply wire to the push wire electrode would be the measurement point of temperature. For certain embodiments, a single temperature measurement on a single push wire electrode could be sufficient. Accordingly, the TC wires552a-bwould be measuring the temperature of the push wire electrode550at a much closer proximity to tissue. In embodiments where the TC wire terminates at the distal tip of the treatment device, the temperature would read near the center of the artery lumen. Reading temperature farther from the target tissue site as well as exposing the tip to a greater amount of blood flow could provide a less accurate tissue temperature, giving more of an estimate of tissue temperature. When the neuromodulation element621is delivered to the renal artery in the delivery state, the radially interior portions of the treatment portions609are pressed up against or in full contact with the support member624. As a result, only portions of the treatment portions609are exposed to the interior of the renal artery RA and thus define the fluid-interface area of the electrodes602,604. Once the neuromodulation element621is adequately positioned at the treatment site, the proximal ends of the electrodes602,604can be pushed distally to begin transformation of the neuromodulation element621from its delivery state to its treatment state. As the electrodes602,604radially expand, the treatment portions609move away from the support member624, thereby exposing the previously unexposed portions of the treatment portions609. During this time, the segments601lengthen as the exposed distal portions603′,605′ of the insulated portions603,605increase in length. The treatment portions609, however, remain generally the same length. As such, at least before the electrodes602,604contact the wall of the renal artery, while the electrodes602,604expand, the fluid-interface area of each of the electrodes602,604can remain generally the same. At some point during deployment, the first and second electrodes602,604can begin to contact an inner surface of the wall of the renal artery. As this occurs, portions of each of the treatment portions609previously in contact with biological fluid may instead begin to contact the wall. Accordingly, a wall-interface area (i.e., the portion of each of the treatment portions609in contact with the wall) may increase as the electrodes602,604continue to expand and additional portions of the treatment portions609engage the wall. For example, wall-interface areas123care illustrated inFIG.5Dwith the renal artery wall omitted for clarity. Expansion of the electrodes602,604can end once the electrodes602,604are in stable apposition with an inner surface of a wall of the renal artery. At this stage of deployment, the segments601are no longer increasing in length, and thus both the wall-interface areas and the fluid-interface areas of the electrodes602,604remain generally constant. At this time, one or both of the electrodes602,604can be energized to modulate one or more nerves at or near the treatment location via the treatment portions609. FIG.6shows a graph of impedance measurements versus time as the neuromodulation element621is delivered and deployed within the lumen. InFIG.6, time t=0 represents a point during delivery/deployment where the neuromodulation element621is located within the lumen at a treatment location in a delivery state. In the delivery state, only the portions of the treatment portions602,604not in contact with the support member624are exposed to biological fluid, and most of the length of the electrode is surrounded by the sleeves612a-b,614a-b, insulation material, or other various components of the catheter12. As such, the measured impedance is relatively high before deployment begins. During a first deployment phase (labeled as “Phase I” inFIG.6), the electrodes602,604begin to radially expand and the treatment portions609move away from the support member624, thereby exposing the previously unexposed portions of the treatment portions609and increasing the fluid-interface area of the electrodes. During this time the measured impedance decreases, as the impedance of biological fluids tends to be less than that of the sleeves612a-b,614a-b, insulation material and/or other components of the catheter12that may be in contact with the electrodes602,604prior to deployment. A second phase of deployment (labeled as “Phase II” inFIG.6) can begin when the electrodes have expanded to a point where the treatment portions609are no longer in contact with the support member624. During the second phase, the electrodes continue to expand and the segments601lengthen. The fluid-interface area, however, remains generally constant. This is because the treatment portions609remain generally the same length during electrode expansion and the added length of the segment601is insulated and does not factor into the fluid-interface area. As such, during this second phase, the fluid-interface area is generally stable, and the impedance is generally stable. During a third deployment phase (labeled as “Phase III” inFIG.6), the treatment portions609of the electrodes602,604begin to contact the lumen wall and impedance measurements increase. This increase in impedance is a result of portions of the fluid-interface area being replaced by wall-interface areas. Lumen walls typically have a higher impedance than biological fluids, and as a result, the measured impedance (which can be a function of the sum of material adjacent the electrode) increases. As shown inFIG.6, a fourth deployment phase (labeled as “Phase IV”) begins when the electrodes602,604have stopped radially expanding and the wall-interface areas stabilize. As such, the impedance measurements during the fourth deployment phase may remain generally constant. It will be appreciated that more or less than four deployment phases are within the scope of the present technology, and the terms “first,” “second,” “third,” and “fourth” are used only for ease of reference. Moreover, although the graphs shown inFIG.4illustrate “increasing” and “decreasing” impedance parabolically and linearly, respectively, impedance measurements can rise and fall along any suitable curve (e.g., exponentially, parabolically, step-wise, other non-linear methods, etc.). Based on the above-described relationships between deployment and impedance, one or more diagnostic algorithms can be used to detect stable contact between one or more of the electrodes and the lumen wall prior to initiating treatment and/or to provide feedback to a clinician as to the status of the contact. For example,FIG.7is a block diagram illustrating a diagnostic algorithm500for determining tissue contact for a single wire electrode in accordance with an embodiment of the present technology. The diagnostic algorithm500includes monitoring impedance (block502) and detecting an increase in impedance above a predetermined threshold IRthat lasts for a predetermined amount of time TIR(block504) (e.g., ΔI≥40 ohms over TIR=2 seconds). Should a sufficient increase in impedance be detected, the algorithm500can include evaluating the impedance measurements collected after the detected increase (e.g., within 1 to 2 ms) and determining whether the detected increase is followed by generally stable (e.g., constant) impedance readings for a predetermined amount of time. For example, as shown in block506, the algorithm500can include identifying the impedance measurements (or set of impedance measurements) collected after the detected impedance increase and determining whether, within those measurements, the absolute change in impedance is below a predetermined threshold IPover the course of a predetermined amount of time TIP(e.g., |ΔI|≤5 ohms over TIP=10 seconds.) As such, the algorithm500can include detecting a transition in impedance measurements between Phase II and Phase III that corresponds to a stabilization of the wall-interface area. Such a stabilization can indicate stable contact between the electrode and the lumen wall, and the algorithm500can include causing the indicator40(FIG.1) to communicate to the user that stable contact has been achieved. In some embodiments, the algorithm500can include communicating to stop expanding the electrodes or cause an electro-mechanical actuator in the handle to stop expanding the electrodes. Additionally or alternatively, the algorithm500can include causing the system10to initiate energy delivery and/or otherwise enable the system10to initiate energy delivery via the electrode. FIG.8is a block diagram illustrating a diagnostic algorithm700for determining tissue contact for a neuromodulation element21having multiple electrodes in accordance with an embodiment of the present technology. Although the algorithm700is described with reference to two electrodes (referred to and labeled as electrodeaand electrodebfor ease of reference), the algorithm700can be used with more than two electrodes. Blocks702a-708acorresponds with electrodeaand702b-708bcorresponds with electrodeb, the description of which generally relate to blocks502-508described above with reference toFIG.7. As shown inFIG.8, the algorithm700can include enabling energy delivery (block712) only if stable contact is detected for electrodeawithin a predetermined time Ts of electrodeb(e.g., stable contact for electrodeaoccurs within 1 second of electrodeb) (block710). It can be advantageous to detect stable contact for all of the electrodes of the neuromodulation element before enabling energy delivery since not all of the electrodes will necessarily achieve stable contact. For example, electrodeamay deploy and reach stable contact with the lumen wall while electrodebdoes not have stable contact (e.g., because of an obstruction or entanglement with a component of the catheter, as a result of the local anatomy, etc.). In other embodiments, the algorithm700can include enabling energy delivery regardless of the timing of detection for electrodeaand electrodeb. For example, where stable contact is detected only for electrodea, energy can be delivered only to electrodeaand not electrodeb. In yet other embodiments, the electrodes can be monitored separately and energy can be delivered only to whichever electrode has achieved stable contact. Selection of Customized Algorithms Based on Pre-Neuromodulation Feedback Before treatment begins, one or more diagnostic algorithms33can detect certain patient attribute(s) which denote a possibility that one or more of the control algorithm(s)30will not provide efficacious treatment to the particular patient and/or adequately evaluate patient-specific physiological parameters in response to neuromodulation. Such patient attributes detected by the diagnostic algorithm(s)33can include, for example, the inner diameter of the body lumen at the treatment location, that are outside of accepted or expected thresholds and/or predetermined or calculated ranges. Accordingly, evaluation of certain patient attributes by the diagnostic algorithm(s)33prior to beginning treatment can inform the clinician as to which control algorithm(s)30are most likely to provide successful neuromodulation to the individual patient. The diagnostic algorithm(s)33can indicate a particular control algorithm30via the indicator40based on the patient profile developed by the diagnostic algorithm33and/or the diagnostic algorithm33can cause the patient profile to be displayed or indicated to the clinician so that the clinician can make an informed selection of the appropriate control algorithm30and/or modification of the control algorithm30. In some instances, the diagnostic algorithm33may indicate that the patient is not a good candidate for neuromodulation and the clinician may decide not to pursue treatment. The inner diameter of the lumen at the treatment location can often be an important patient attribute since it can inform the clinician as to the appropriate control algorithm30or energy delivery profile to utilize during treatment. Lumen inner diameters can vary from patient to patient, and as a result, a standardized control algorithm(s)30may not be appropriate across all treatments. For example, if a patient has relatively large lumen inner diameter, the energy delivered may not reach a predetermined maximum power level before a predetermined treatment time expires (and before the tissue can be adequately heated by the electrodes). If a patient has relatively small lumen inner diameter, the electrode(s) can heat up too quickly. Accordingly, disclosed herein are one or more diagnostic algorithms33that determine contact prior to initiating treatment and provide feedback to the clinician as to selection and/or modification of the control algorithm30. FIG.9is a block diagram illustrating a diagnostic algorithm800for determining lumen inner diameter at the treatment location in accordance with an embodiment of the present technology. The description of blocks802-808generally correspond to blocks602-608ofFIG.5. In some embodiments, the catheter12(FIG.1) can include a gauge (not shown) coupled to one or more electrodes and configured to measure the longitudinal shift of the electrode(s) relative to the shaft during deployment. As shown in block810, at the time stable contact between the electrode and lumen wall is detected, the longitudinal shift of the electrode can be measured. The measured longitudinal shift of the electrode can then be used to determine the inner diameter of the lumen at the treatment site based on predetermined data that correlates various longitudinal shift values to lumen inner diameter values. Based on the lumen inner diameter, the algorithm800can include selecting an appropriate control algorithm or adjusting the existing control algorithm. In some embodiments, the user can manually select the appropriate control algorithm based on the feedback. The control algorithm30can be adjusted (or the appropriate control algorithm selected) to have a direct or indirect linear relationship such that a greater amount of energy is delivered when the longitudinal shift at the time of detection of stable contact is relatively large. Likewise, the control algorithm30can be adjusted (or the appropriate control algorithm selected) such that a lesser amount of energy is delivered when the longitudinal shift at the time of detection of stable contact is relatively small. Additionally or alternatively, the control algorithm30can be adjusted (or the appropriate control algorithm selected) to have a direct or indirect linear relationship such that energy is delivered for a longer time period when the longitudinal shift at the time of the transition of the electrical property is relatively large. Likewise, the control algorithm30can be adjusted (or the appropriate control algorithm selected) such that a shorter time period when the longitudinal shift at the time of the transition of the electrical property is relatively small. Selected Embodiments of Energy Delivery Profiles With the treatments disclosed herein for delivering neuromodulation treatment to target tissue, it may be beneficial for energy to be delivered to the target neural structures in a controlled manner. The controlled delivery of energy will allow the zone of thermal treatment to extend into the renal fascia while reducing undesirable energy delivery or thermal effects to the lumen wall. A controlled delivery of energy may also result in a more consistent, predictable and efficient overall treatment. Accordingly, the console26desirably includes a controller42(FIG.1) including a memory component with instructions for executing a control algorithm30for controlling the delivery of power and energy to the energy delivery device. For example,FIG.10illustrates one example of a control algorithm30configured in accordance with an embodiment of the present technology. When a clinician initiates treatment, the control algorithm30includes instructions to the console26to gradually adjust its power output to a first power level P1(e.g., 4 watts) over a first time period t1(e.g., 15 seconds). The power can increase generally linearly during the first time period. As a result, the console26increases its power output at a generally constant rate of P1/t1. Alternatively, the power may increase exponentially, parabolically, step-wise, and/or other non-linear methods. Once P1and t1are achieved, the algorithm may hold at P1 until a new time t2 for a predetermined period of time t2−t1(e.g., 1 second). At t2power is increased by a predetermined rate (e.g., 0.5 watts/seconds) to a maximum power PMAX(e.g., 6 watts, 10 watts, etc.) over a predetermined period of time, t3−t2(e.g., 1 second). In other embodiments, the control algorithm30applies the maximum power PMAXimmediately upon initiation of energy delivery and maintains PMAXfor the total treatment time (e.g., up to about 120 seconds) and/or steps down the power from PMAXduring the remainder of treatment. Although the control algorithm30ofFIG.10comprises a power-control algorithm, it should be understood that the control algorithm30additionally or alternatively may include temperature control and/or current control. For example, power may be initiated when a combination of impedance requirements and temperature requirements are met, power may be gradually increased until a desired temperature (or temperatures) is obtained for a desired duration (or durations), or power may be ceased when a threshold temperature or specific impedance change is measured. The control algorithm30also can include continuously and/or periodically monitoring certain operating parameters such as time, electrical properties (e.g., impedance, voltage, current, power, etc.) and/or other suitable parameters. The control algorithm30can also include calculating and/or monitoring derivatives of such operating parameters, such as impedance over a specified time, a maximum impedance, a maximum average impedance, a minimum impedance, an impedance at a predetermined or calculated time relative to a predetermined or calculated impedance, an average impedance over a specified time, and other suitable derivatives. As used herein, “operating parameters” includes operating parameter measurements, derivatives, manipulations, etc. Measurements may be taken at one or more predetermined times, ranges of times, calculated times, and/or times when or relative to when a measured event occurs. Renal Neuromodulation Renal neuromodulation is the partial or complete incapacitation or other effective disruption of nerves innervating the kidneys (e.g., rendering neural fibers inert or inactive or otherwise completely or partially reduced in function). For example, renal neuromodulation can include inhibiting, reducing, and/or blocking neural communication along neural fibers (i.e., efferent and/or afferent nerve fibers) innervating the kidneys. Such incapacitation can be long-term (e.g., permanent or for periods of months, years, or decades) or short-term (e.g., for periods of minutes, hours, days, or weeks). Renal neuromodulation is expected to efficaciously treat several clinical conditions characterized by increased overall sympathetic activity, and, in particular, conditions associated with central sympathetic overstimulation such as hypertension, heart failure, acute myocardial infarction, metabolic syndrome, insulin resistance, diabetes, left ventricular hypertrophy, chronic and end stage renal disease, inappropriate fluid retention in heart failure, cardio-renal syndrome, osteoporosis, and sudden death, among others. The reduction of afferent neural signals typically contributes to the systemic reduction of sympathetic tone/drive, and renal neuromodulation is expected to be useful in treating several conditions associated with systemic sympathetic overactivity or hyperactivity. Renal neuromodulation can potentially benefit a variety of organs and bodily structures innervated by sympathetic nerves. Thermal effects can include both thermal ablation and non-ablative thermal alteration or damage (e.g., via sustained heating and/or resistive heating) to partially or completely disrupt the ability of a nerve to transmit a signal. Desired thermal heating effects, for example, may include raising the temperature of target neural fibers above a desired threshold to achieve non-ablative thermal alteration, or above a higher temperature to achieve ablative thermal alteration. For example, the target temperature can be above body temperature (e.g., approximately 37° C.) but less than about 45° C. for non-ablative thermal alteration, or the target temperature can be about 45° C. or higher for ablative thermal alteration. More specifically, exposure to thermal energy in excess of a body temperature of about 37° C., but below a temperature of about 45° C., may induce thermal alteration via moderate heating of target neural fibers or of vascular structures that perfuse the target fibers. In cases where vascular structures are affected, the target neural fibers may be denied perfusion resulting in necrosis of the neural tissue. For example, this may induce non-ablative thermal alteration in the fibers or structures. Exposure to heat above a temperature of about 45° C., or above about 60° C., may induce thermal alteration via substantial heating of the fibers or structures. For example, such higher temperatures may thermally ablate the target neural fibers or the vascular structures that perfuse the target fibers. In some patients, it may be desirable to achieve temperatures that thermally ablate the target neural fibers or the vascular structures, but that are less than about 90° C., or less than about 85° C., or less than about 80° C., and/or less than about 75° C. Other embodiments can include heating tissue to a variety of other suitable temperatures. Regardless of the type of heat exposure utilized to induce the thermal neuromodulation, a therapeutic effect (e.g., a reduction in renal sympathetic nerve activity (RSNA)) is expected. Various techniques can be used to partially or completely incapacitate neural pathways, such as those innervating the kidneys. The purposeful application of energy (e.g., RF energy, mechanical energy, acoustic energy, electrical energy, thermal energy, etc.) to tissue and/or the purposeful removal of energy (e.g., thermal energy) from tissue can induce one or more desired thermal heating and/or cooling effects on localized regions of the tissue. The tissue, for example, can be tissue of the renal artery and adjacent regions of the renal plexus, which lay intimately within or adjacent to the adventitia of the renal artery. For example, the purposeful application and/or removal of energy can be used to achieve therapeutically effective neuromodulation along all or a portion of the renal plexus. V. FURTHER EXAMPLES The following examples are illustrative of several embodiments of the present technology: 1. A method, comprising:advancing a catheter including an elongate shaft and a neuromodulation element operably connected to the shaft toward a treatment location within a body lumen of a human patient, the neuromodulation element including an elongate electrode slidably disposed within a dielectric sleeve;deploying the neuromodulation element from a delivery state to a treatment state after advancing the catheter, deploying the neuromodulation element including—a first deployment phase during which the electrode moves radially outward while a first interface area between the electrode and the dielectric sleeve decreases and a second interface area between the electrode and a biological fluid at the treatment location increases,a second deployment phase following the first deployment phase, the first interface area decreasing and a third interface area between the electrode and a lumen wall at the treatment location increasing during the second deployment phase, anda third deployment phase following the second deployment phase, wherein during the third deployment phase the third interface area more stable than it is during the second deployment phase; andusing the electrode to measure an electrical property of a sum of material adjacent to the electrode while deploying the neuromodulation element, the sum of material adjacent to the electrode including portions of the dielectric sleeve, the lumen wall and the biological fluid adjacent to the electrode;detecting a transition of the electrical property corresponding to a transition from the second deployment phase to the third deployment phase; andgenerating a status indication, enabling a neuromodulation treatment, or both in response to detecting the transition of the electrical property. 2. The method of example 1 wherein the electrical property is impedance. 3. The method of example 1 or example 2 wherein detecting the transition of the electrical property includes detecting a transition of a rate of change of the electrical property. 4. The method of example 1 or example 2 wherein detecting the transition of the electrical property includes:detecting a rate of change of the electrical property to be greater than a first threshold rate of change for a first time period; anddetecting the rate of change of the electrical property to be less than a second threshold rate of change for a second time period after the first time period. 5. The method of any of examples 1-4 wherein the electrode is a wire electrode. 6. The method of example 5 wherein the wire electrode is at least generally helical during the third deployment phase. 7. The method of any of examples 1-6 wherein deploying the neuromodulation element includes pushing a proximal end of the electrode in a distal direction. 8. A method, comprising:advancing a catheter including an elongate shaft and a neuromodulation element operably connected to the shaft toward a treatment location within a body lumen of a human patient, the neuromodulation element including a first elongate electrode slidably disposed within a first dielectric sleeve and a second elongate electrode slidably disposed within a second dielectric sleeve;deploying the first electrode after advancing the catheter, deploying the first electrode including—a first deployment phase during which the first electrode moves radially outward while a first interface area of the first electrode between the first electrode and the first dielectric sleeve decreases and a second interface area of the first electrode between the first electrode and a biological fluid at the treatment location increases,a second deployment phase following the first deployment phase of deploying the first electrode, the first interface area of the first electrode decreasing and a third interface area of the first electrode between the first electrode and a lumen wall at the treatment location increasing during the second deployment phase of deploying the first electrode, anda third deployment phase following the second deployment phase of deploying the first electrode, wherein during the third deployment phase of deploying the first electrode the third interface area of the first electrode is more stable than it is during the second deployment phase of deploying the first electrode; anddeploying the second electrode after advancing the catheter, deploying the second electrode including—a first deployment phase during which the second electrode moves radially outward while a first interface area of the second electrode between the second electrode and the second dielectric sleeve decreases and a second interface area of the second electrode between the second electrode and the biological fluid at the treatment location increases,a second deployment phase following the first deployment phase of deploying the second electrode, the second interface are of the second electrode decreasing and a third interface area of the second electrode between the electrode and the lumen wall at the treatment location increasing during the second deployment phase of deploying the second electrode, anda third deployment phase following the second deployment phase of deploying the second electrode, wherein during the third deployment phase of deploying the second electrode while the third interface area of the second electrode is more stable than it is during the second deployment phase of deploying the second electrode; andusing the first electrode to measure a first electrical property of a first sum of material adjacent to the first electrode while deploying the neuromodulation element, the first sum of material adjacent to the first electrode including portions of the first dielectric sleeve, the lumen wall and the biological fluid adjacent to the first electrode;using the second electrode to measure a second electrical property of a second sum of material adjacent to the second electrode while deploying the neuromodulation element, the second sum of material adjacent to the second electrode including portions of the second dielectric sleeve, the lumen wall and the biological fluid adjacent to the second electrode;detecting a transition of the first electrical property corresponding to a transition from the second deployment phase of deploying the first electrode to the third deployment phase of deploying the first electrode;detecting a transition of the second electrical property corresponding to a transition from the second deployment phase of deploying the second electrode to the third deployment phase of deploying the second electrode; andgenerating a status indication, enabling a neuromodulation treatment, or both in response to detecting the transition of the first electrical property, second electrical property, or both. 9. The method of example 8 wherein generating a status indication, enabling a neuromodulation treatment, or both is in response to detecting an intervening time period between the transition of the first electrical property and the transition of the second electrical property that is less than a threshold time period. 10. The method of example 8 or example 9 wherein:the first electrical property is a first impedance; andthe second electrical property is a second impedance. 11. The method of any of examples 8-10 wherein:detecting the transition of the first electrical property includes detecting a transition of a rate of change of the first electrical property; anddetecting the transition of the second electrical property includes detecting a transition of a rate of change of the second electrical property. 12. The method of any of examples 8-10 wherein:detecting the transition of the first electrical property includes—detecting a rate of change of the first electrical property to be greater than a first threshold rate of change for a first time period; anddetecting the rate of change of the first electrical property to be less than a second threshold rate of change for a second time period after the first time period; anddetecting the transition of the second electrical property includes—detecting a rate of change of the second electrical property to be greater than a third threshold rate of change for a third time period; anddetecting the rate of change of the second electrical property to be less than a fourth threshold rate of change for a fourth time period after the third time period. 13. The method of example 12 wherein:the first and third threshold rates of change are the same;the first and third time periods are the same;the second and fourth threshold rates of change are the same; andthe second and fourth time periods are the same. 14. The method of any of examples 8-13 wherein:the first electrode is a first wire electrode; andthe second electrode is a second wire electrode. 15. The method of example 14 wherein:the first wire electrode is at least generally helical during the third deployment phase of deploying the first wire electrode; andthe second wire electrode is at least generally helical during the third deployment phase of deploying the second wire electrode. 16. The method of example 15 wherein the first and second wire electrodes are helically intertwined during the third deployment phase of deploying the first wire electrode and during the third deployment phase of deploying the second wire electrode. 17. A method, comprising:advancing a catheter including an elongate shaft and a neuromodulation element operably connected to the shaft toward a treatment location within a body lumen of a human patient, the neuromodulation element including an elongate electrode slidably disposed within a dielectric sleeve;moving an elongate control member relative to the shaft, moving the shaft relative to the control member, or both so as to cause a longitudinal shift between the control member and the shaft and thereby cause the electrode to move radially outward while a wall-interface area between the electrode and a lumen wall at the treatment location increases;measuring the longitudinal shift while moving the control member;using the electrode to measure an electrical property of a sum of material adjacent to the electrode while the electrode moves radially outward, the sum of material adjacent to the electrode including portions of the dielectric sleeve, the lumen wall and the biological fluid adjacent to the electrode,detecting a transition of the electrical property corresponding to a stabilization of the wall-interface area; anddelivering energy to one or more nerves of the patient via the electrode according to a profile of energy over time, the profile being based on the longitudinal shift at the time of the transition of the electrical property, the longitudinal shift at the time of the transition of the electrical property corresponding to a diameter of the body lumen. 18. The method of example 17 wherein delivering energy to the one or more nerves via the electrode includes delivering a greater amount of energy to the one or more nerves when the longitudinal shift at the time of the transition of the electrical property is relatively large and delivering a lesser amount of energy to the one or more nerves when the longitudinal shift at the time of the transition of the electrical property is relatively small. 19. The method of example 17 wherein delivering energy to the one or more nerves via the electrode includes delivering energy to the one or more nerves for a longer time period when the longitudinal shift at the time of the transition of the electrical property is relatively large and energy to the one or more nerves for a shorter time period when the longitudinal shift at the time of the transition of the electrical property is relatively small. 20. The method of any of examples 17-19, further including indicating the diameter of the body lumen. 21. A method, comprising:advancing a catheter including an elongate shaft and a neuromodulation element operably connected to the shaft toward a treatment location within a body lumen of a human patient, the neuromodulation element including an elongate electrode slidably disposed within a dielectric sleeve;deploying the neuromodulation element from a delivery state to a treatment state after advancing the catheter, deploying the neuromodulation element including—a first deployment phase during which the electrode moves radially outward while a first interface area between the electrode and a biological fluid at the treatment location increases,a second deployment phase following the first deployment phase, wherein the first interface area is generally constant during the second deployment phase;a third deployment phase following the second deployment phase, the first interface area decreasing and the second interface area between the electrode and a lumen wall at the treatment location increasing during the third deployment phase, anda fourth deployment phase following the third deployment phase, the third interface area is more stable than it is during the third deployment phase; andusing the electrode to measure an electrical property of a sum of material adjacent to the electrode while deploying the neuromodulation element, the sum of material adjacent to the electrode including portions of the dielectric sleeve, the lumen wall and the biological fluid adjacent to the electrode;detecting a transition of the electrical property corresponding to a transition from the third deployment phase to the fourth deployment phase; andgenerating a status indication, enabling a neuromodulation treatment, or both in response to detecting the transition of the electrical property. 22. The method of example 21 wherein the electrical property is impedance. 23. The method of example 21 or example 22 wherein detecting the transition of the electrical property includes detecting a transition of a rate of change of the electrical property. 24. The method of example 21 or example 22 wherein detecting the transition of the electrical property includes:detecting a rate of change of the electrical property to be greater than a first threshold rate of change for a first time period; anddetecting the rate of change of the electrical property to be less than a second threshold rate of change for a second time period after the first time period. 25. The method of any of examples 21-24 wherein the electrode is a wire electrode. 26. The method of example 25 wherein the wire electrode is at least generally helical during the fourth deployment phase. 27. The method of any of examples 21-26 wherein deploying the neuromodulation element includes pushing a proximal end of the electrode in a distal direction. VI. CONCLUSION The above detailed descriptions of embodiments of the technology are not intended to be exhaustive or to limit the technology to the precise form disclosed above. Although specific embodiments of, and examples for, the technology are described above for illustrative purposes, various equivalent modifications are possible within the scope of the technology, as those skilled in the relevant art will recognize. For example, while steps are presented in a given order, alternative embodiments may perform steps in a different order. The various embodiments described herein may also be combined to provide further embodiments. From the foregoing, it will be appreciated that specific embodiments of the technology have been described herein for purposes of illustration, but well-known structures and functions have not been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments of the technology. Where the context permits, singular or plural terms may also include the plural or singular term, respectively. Certain aspects of the present technology may take the form of computer-executable instructions, including routines executed by a controller or other data processor. In some embodiments, a controller or other data processor is specifically programmed, configured, and/or constructed to perform one or more of these computer-executable instructions. Furthermore, some aspects of the present technology may take the form of data (e.g., non-transitory data) stored or distributed on computer-readable media, including magnetic or optically readable and/or removable computer discs as well as media distributed electronically over networks. Accordingly, data structures and transmissions of data particular to aspects of the present technology are encompassed within the scope of the present technology. The present technology also encompasses methods of both programming computer-readable media to perform particular steps and executing the steps. Moreover, unless the word “or” is expressly limited to mean only a single item exclusive from the other items in reference to a list of two or more items, then the use of “or” in such a list is to be interpreted as including (a) any single item in the list, (b) all of the items in the list, or (c) any combination of the items in the list. Additionally, the term “comprising” is used throughout to mean including at least the recited feature(s) such that any greater number of the same feature and/or additional types of other features are not precluded. It will also be appreciated that specific embodiments have been described herein for purposes of illustration, but that various modifications may be made without deviating from the technology. Further, while advantages associated with certain embodiments of the technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the technology. Accordingly, the disclosure and associated technology can encompass other embodiments not expressly shown or described herein.

11857250

DETAILED DESCRIPTION OF THE INVENTION The present disclosure advantageously provides examples of medical systems and components thereof providing multiple effectively-controllable shapes or dimensions that can be selectively manipulated to provide varying treatment patterns. In particular and as shown inFIG.1, a medical system, generally designated as “10,” is provided for diagnosing and/or treating unwanted tissue conditions, including atrial fibrillation or other arrhythmias. The medical system may generally include a radiofrequency (“RF”) signal generator12having a user interface for the operation and control thereof, an electrocardiogram (“ECG”) unit14operably coupled to or otherwise interfaced with the RF signal generator12, and a medical device16operably coupled to or otherwise interfaced with the RF signal generator12and/or the ECG unit14. Now referring toFIGS.1-6, the medical device16may include a catheter body sized and dimensioned to intraluminally and transseptally access a left atrium of a patient's heart for the subsequent treatment or ablation thereof. The medical device16may generally define an elongated, flexible catheter body18having a distal diagnostic/treatment assembly20, as well as a handle assembly22at a proximal end or portion of the catheter body18. The catheter body18may define one or more lumens therethrough, to allow for the passage of a guide wire24or the like therethrough. The catheter body18may include reinforcement elements or otherwise be constructed to provide desired degrees of stiffness, flexibility, and/or torque transmission along the length of the body and at discrete locations along the length thereof. For example, the catheter body18may include wires, braiding, increased wall-thickness, additional wall layering, sleeves, or other components reinforcing or otherwise supplementing an outer wall or thickness along its length. Discrete portions that may experience significant loading or torque during a particular procedure may also include such reinforcement. Now referring toFIGS.2-5, the distal diagnostic/treatment assembly20provides for the treatment, monitoring, and/or otherwise clinically interacting with a desired tissue region, such as the heart. The treatment assembly20may include, for example, an electrode array28disposed near, on, or substantially on the distal end of the catheter body. The electrode array28may include a plurality of electrodes30along its length. These electrodes30may be symmetrically or asymmetrically mounted to detect electrical signals between any pair of electrodes (bi-pole) for mapping of electrical activity, and/or for performing other functions such as pacing of the heart. Moreover, the electrodes30may deliver ablation energy across an electrode pair or from independent electrodes when delivering monopolar energy. Each electrode30may include an integral thermocouple (not shown) located on or near the tissue side of the electrode to monitor the temperature at each ablation site before and during ablation. The electrodes30may be constructed from platinum, iridium, gold, silver or the like, and may measure approximately about 3 mm in length and separated by a distance of approximately 1 mm to approximately 4 mm, for example. Each of the electrodes may be electrically coupled to the RF signal generator12, which may also be attached to a patch or ground electrode34(attached to the back of the patient, for example) to enable the delivery of monopolar ablation energy when desired. While monopolar and bipolar RF ablation energy may be the selected forms of energy to pass through the electrodes of the medical device, other forms of ablation energy may be additionally or alternatively emitted from the treatment assembly, including electrical energy, magnetic energy, microwave energy, thermal energy (including heat and cryogenic energy) and combinations thereof. Moreover, other forms of energy that may be applied can include acoustic energy, sound energy, chemical energy, photonic energy, mechanical energy, physical energy, radiation energy and a combination thereof. As shown inFIGS.2-5, the treatment assembly20of the medical device16may include a carrier assembly36that supports the electrode array28thereon. The carrier assembly36may include a flexible carrier arm38having one end coupled to the catheter body18and/or handle assembly22. The carrier arm38may be constructed from a shape memory material, such as nitinol, to provide one or more pre-determined and/or biased geometric configurations. The carrier assembly36may include reinforcement elements or otherwise be constructed to provide desired degrees of stiffness, flexibility, and/or torque transmission along its length or at discrete locations along the length thereof. For example, the carrier arm38may include wires, braiding, increased wall-thickness, additional wall layering, sleeves, or other components reinforcing or otherwise supplementing an outer wall or thickness to minimize the likelihood of structural failure resulting from the experienced torque or strain. Conventional marking elements (e.g. radiopaque markers) may be included in the distal treatment assembly20, carrier assemblies or other components of the medical device16to determine the relative location of the carrier assembly and/or the deployment condition of the carrier assembly, as well as confirm contact with tissue. Referring now toFIGS.2-3, the carrier arm38may extend from a distal end of the catheter body18in a substantially coaxial arrangement with the catheter body18and/or a guide wire lumen defined therein. The carrier arm38may further define an opening or aperture40allowing passage of the guide wire24therethrough. As a result, the guide wire24may be used to direct the distal assembly20of the medical device16into a desired position within the patient when the carrier assembly36is in a minimized, substantially linear configuration. Further, the aperture40enables manipulation and steering of the guide wire24independently of the carrier assembly36, allowing the distal portion of the medical device16to be directed over-the-wire irrespective of the geometric shape or configuration the carrier assembly is in, or what the particular rotational position of the carrier assembly is with respect to the guide wire24. For example,FIG.2illustrates the carrier assembly36in a first geometric configuration for diagnosing or treating a tissue area, whileFIG.3illustrates an additional geometric configuration. Now turning toFIGS.4-5, the carrier assembly36may extend from a distal end of the catheter body18offset or spaced from an opening in the distal end where the guide wire24exits the catheter body18. This configuration again allows for independent and separate operation or manipulation of the carrier assembly36and the guide wire24when the distal assembly20is in the treatment area, which may include for example one or more chambers of the heart. The electrode array28may be arranged in a resiliently biased manner and have specific geometric configurations which generally allow the electrodes30to ablate specific tissue (such as a pulmonary vein, for example) having predetermined or otherwise known geometric or topographical characteristics. The electrode array28may be selectively movable from a primary, stored or delivery configuration for transport and delivery to the treatment site (such as a radially constrained configuration) to multiple secondary, deployed or expanded configurations for treatment. Referring now toFIGS.2-5, the electrodes30may be spaced along a fraction of the length of the carrier arm38(for example, between approximately 40% to approximately 60% of the overall length) such that, when deployed into an expanded configuration, the electrodes constitute a substantially semi-circular array. The fractional length and substantially semi-circular configuration of the electrodes allows a user to provide therapy with the electrodes around larger/common ostia or vessel orifices, as well as providing increased ability to create larger, wider-area patterns of treatment on more antral surfaces or tissue regions. Referring now toFIGS.6-7, the medical device16may include a shaft42extending distally from the catheter body18. The shaft42may be substantially rigid (e.g, constructed of stainless steel or the like) and define a lumen therein for the passage of the guide wire24. A flexible coil44may be coupled to the shaft42, and the coil44may be deflectable or steerable from the handle22of the device16, and/or the coil44may define a lumen therethrough for passage of the guide wire24to facilitate over-the-wire direction of the medical device16. An intermediate conduit46may be disposed between the shaft42and the coil44, where the intermediate conduit provides a degree of rigidity less than the shaft42but greater than the coil44, thus providing a transitional area that can deflect or bend to a degree during deflection or steering of the medical device16. The intermediate conduit may be constructed, for example of nitinol or other material having the desired degree of flexibility. The carrier arm38and/or carrier assembly36may be movably coupled to the shaft42, and the shaft may be movable with respect the catheter body18to aid in shaping or manipulating the carrier assembly36into a desired configuration. The carrier arm38may define an eyelet or opening slidably positionable along a length of the shaft42, for example. A distal stop48may be coupled to the shaft42to limit a range of movement of the carrier assembly36and/or prevent unintentional retraction/de-coupling of the shaft42and the carrier assembly26. The stop48may include an expanded diameter portion or other mechanical obstacle preventing movement of the carrier assembly36past a certain point. The handle assembly22of the medical device may include one or more mechanisms or components to facilitate manipulation of the shaft and/or the distal treatment assembly. For example, as shown inFIG.8, the handle assembly22may include a linear actuator50providing for the proximal-distal extension and retraction of the shaft42and/or carrier assembly36. The linear actuator50may be movably coupled to a portion of the handle assembly22to allow it to slide or otherwise translate in a proximal-to-distal direction, and vice versa. The handle assembly22may further include a housing coupled to the linear actuator50and/or handle assembly22to facilitate movement and/or linkage of the actuator and the shaft42and/or carrier assembly36. A rotational actuator52may also be disposed on or about the handle assembly22to facilitate rotation of the shaft42and/or carrier assembly36about a longitudinal axis of the catheter body18in two directions. The rotational actuator52may be directly coupled to the shaft, or alternatively, include one or more intermediary components to effectuate a controllable, mechanical linkage between the rotational actuator and the shaft42and/or carrier assembly36, such as a secondary gear assembly. One or more internal push/pull wires may also be provided in the medical device16, and in particular, coupled to the handle assembly22. For example, to facilitate single or bi-directional steering and control of the distal treatment assembly20, a full length pull wire (or double pull wires such as in the case with bi-directional steering, neither of which is shown) may be secured to the a distal portion of the end of the shaft42and/or carrier assembly36. The pull wire may extend proximally to a steering knob54. Rotation of the knob54may pull the wire that, in turn, controls the plane in which the electrodes contact tissue. The medical device may further include a capture element56that is friction fit over a distal end of the handle assembly22. The capture element56may be configured to be detached therefrom and slide in a distal direction over the catheter body18until the electrode array28is received therein, in a stored or confined configuration. The capture element56may be applied over the electrode array28for constraint and protection thereof during delivery through a hemostasis valve of a transseptal sheath or a vascular introducer. In this manner, the array may be introduced safely (e.g. without damage) into the patient's vasculature (e.g., a femoral vein). After introduction of electrode array28through the hemostasis valve, the capture element56may be moved proximally over the catheter body and reattached to the distal end portion of the handle assembly22to function as a strain relief. The RF signal generator12functions to generate RF energy as supplied to selected catheter electrodes or between selected pairs of electrodes for the electrode array28to ablate or otherwise treat cardiac tissue. In particular, the RF signal generator12may be configured to generate and control the delivery of RF energy based on temperature feedback from the respective thermocouple of each electrode30. Each electrode30may be independently monitored followed by temperature-controlled delivery of RF energy. Energy delivery may further automatically be duty-cycled to maximize the delivery of RF energy to the electrode based on the measured tissue temperature. Hence, as the tissue temperature increases due to delivery of RF energy (resistive heating), the electrodes30in turn increase in temperature, as monitored by the corresponding thermocouple. For instance, during bipolar delivery, if the set target temperature of the electrodes is 60° C. and one of the two electrodes is monitored at 55° C., while the other electrode is monitored to be at 50° C., the generator will selectively limit energy delivery based on the needs of one electrode measured at 55° C. This prevents either electrode of the pair from ever significantly surpassing the set target temperature. In contrast, during a monopolar phase of the energy delivery, the RF signal generator will deliver RF energy to each electrode30solely based on the temperature measured by its corresponding thermocouple. The temperature measurements may be performed between RF duty cycles (off-cycles) to minimize interference and to optimize accuracy of temperature readings. The RF signal generator12may also include a user interface56and/or a remote control58(shown inFIG.1). The user interface56allows a user to select parameters for the desired mapping and/or ablation treatment. The user interface56may allow the user to select an energy delivery mode for the treatment. For example, the user interface56can allow the user to select the delivery of only monopolar energy, only bipolar energy, or a combination of the two. The user interface may also allow the user to select a power ratio, such as 1:1, 2:1, or 4:1, when in combination mode. The generator12can be manufactured to include specific alternative power ratios (e.g., 1:1, 2:1, 4:1), such that the user can select one of the established ratios, and/or the user interface can allow the user to enter a different power ratio. The user interface56may also allow the user to change the energy mode when the catheter is changed, or when the medical device is moved to a different location in order to ablate different tissue. The ECG unit14is provided to monitor and map signals detected by the electrodes of each electrode array. These two units (i.e., the RF signal generator12the ECG unit14) may be interfaced in parallel, via the ECG interface14, to the medical device16. The ECG unit14electrically isolates the ECG unit14from any damaging signals generated by the RF generator12. The ECG unit14may also be configured to isolate the ECG monitoring unit from electrical noise generated by the delivery of the RF energy. In an exemplary use of the present system, the medical device16may be used to investigate and treat aberrant electrical impulses or signals in a selected tissue region, such as in the heart. Primarily, the distal treatment assembly20may be advanced through the patient's vasculature via the femoral vein over a previously inserted guide wire24. The distal treatment assembly20may then be advanced into the right atrium and into proximity of a pulmonary vein, for example. In order to advance the carrier assembly36through the vasculature and into the desired position, the distal treatment assembly20(including the carrier assembly36and the electrode array28) may be oriented in a first, substantially linear transport configuration. The first, substantially linear transport configuration may be achieved through the manipulation of the linear actuator50on the handle assembly22. In turn, the flexible carrier arm38may be urged toward the substantially linear configuration. In this linear orientation, the carrier assembly is minimized and compact in a transverse dimension for easily advanced through the vasculature (or a transseptal sheath). Once in the desired proximity to the target tissue, the carrier assembly36and the electrode array28may be deployed into a second, expanded geometric configuration using one or more of the rotational actuator52and/or linear actuator50. Upon obtaining the desired geometric configuration of the carrier assembly and electrode array, the steering mechanism of the medical device (e.g., the steering knob54and the internal pull wire or wires) may be used to deflect the array28to contact the target tissue. The deflection may be achieved independently of the placement or manipulation of the guide wire24. At this juncture, the geometric configuration of the electrode array28can be further adjusted to achieve optimal contact with the surrounding targeted tissue. Further, once a desired configuration of the carrier assembly36has been achieved, the configuration may be maintained when moving from one position or tissue treatment area to another region or tissue treatment area using the guide wire24. Such methodology would allow a user, for example, to configure the carrier assembly36and electrode array28into the desired size or shape for a first pulmonary vein (or other tissue structure), then move the array28over the guide wire24to a similar structure (e.g., a second pulmonary vein) without the need to modify the shape of the array. Once in the desired position, sufficient contact with tissue may be determined when the carrier assembly transitions to a convex shape or through fluoroscopic imaging. In addition, the location and tissue contact can be confirmed using the electrodes30of the medical device. For example, an electrophysiologist can map the contacted tissue to not only determine whether or not to ablate any tissue, but to also confirm tissue contact which is identified in the mapping procedure. If conditions are determined to be inadequate, an operator may adjust the shape or deflection of carrier assembly and/or the operator may reposition carrier assembly36against tissue through various manipulations performed at the proximal end of medical device16. Moreover, it will be appreciated that other conventional mapping catheters can be applied to map signals, such as a standard electrophysiology lasso catheter. Once sufficient tissue contact has been established and the mapping procedure has confirmed the presence of aberrant conductive pathways, ablation energy may be passed through the electrodes30(i.e., 5-10 Watts) of the electrode array28. The electrode array28and the RF signal generator12may cooperate to deliver RF energy in monopolar, bipolar or combination monopolar-bipolar energy delivery modes, simultaneously or sequentially, and with or without durations of terminated energy delivery. Depending upon a number of primary factors, such as the geometry and location of targeted tissue region, the quality of the electrode/tissue contact, the selected magnitude of the RF energy delivered to the electrodes, the type of RF energy applied, as well as the duration of the ablation, lesion formation can be estimated that is sufficient to eliminate aberrant conductive pathways therethrough. For example, given the above factors, a target temperature of the ablated tissue may be about 60° C., with a lower limit of about 55° C. and an upper limit of about 65° C. It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope and spirit of the invention, which is limited only by the following claims.

11857251

DETAILED DESCRIPTION As used herein, the terms “insulator,” “insulation material,” “insulative material,” and the like, each connote materials and structures comprising at least one material that has properties, generally accepted by those of skill in the art, to resist transfer of heat and conveyance of electrical signals. Such materials include, but are not limited to, polyamide, polyimide, polyurethane, polycarbonate, ceramic, liquid crystal polymer, and high-temperature epoxy. As used herein, the terms “about” or “approximately” for any numerical values or ranges indicate a suitable dimensional tolerance that allows the part or collection of components to function for its intended purpose as described herein. More specifically, “about” or “approximately” may refer to the range of values ±20% of the recited value, e.g. “about 90%” may refer to the range of values from 71% to 99%. As used herein, a “subject” or “patient” may refer to any applicable human patient as well as any mammal, veterinarian animal, livestock animal or pet type animal, etc. As an example, the animal may be a laboratory animal specifically selected to have certain characteristics similar to a human (e.g., rat, dog, pig, rabbit, monkey, or the like). As used herein, “operator” may include a doctor, surgeon, or any other individual or instrumentation associated with the medical procedure used with the device(s) of this disclosure. Ablation, particularly of cardiac tissue, depends upon accurate delivery of ablative energy while avoiding negative side effects caused by providing ablative energy to blood such as thrombus formation. A catheter having a tip divided into three segments directed to these purposes is disclosed. FIG.1depicts a system10for evaluating electrical activity and performing ablative procedures on a heart12of a living subject. The system includes a diagnostic/therapeutic catheter having a catheter body14having a distal end15and a tip, e.g., tip18disposed thereon, which may be percutaneously inserted by an operator16through the patient's vascular system into a chamber or vascular structure of the heart12. The operator16, who is typically a physician, brings the catheter's tip18into contact with the heart wall, for example, at an ablation target site. Electrical activation maps may be prepared, according to the methods disclosed in U.S. Pat. Nos. 6,226,542, and 6,301,496, and in commonly assigned U.S. Pat. No. 6,892,091, whose disclosures are herein incorporated by reference in their entirety. One commercial product embodying elements of system10is available as the CARTO® 3 System, available from Biosense Webster, Inc., 33 Technology Drive, Irvine, CA 92618. Areas determined to be abnormal, for example by evaluation of the electrical activation maps, can be ablated by application of thermal energy, e.g., by passage of radiofrequency electrical current through wires in the catheter to one or more electrodes at the tip18, which apply the radiofrequency energy to target tissue. The energy is absorbed in the tissue, heating it to a point (typically above 50° C.) at which point it permanently loses its electrical excitability. This procedure creates non-conducting lesions in the cardiac tissue, which disrupt the abnormal electrical pathway causing the arrhythmia. Such principles can be applied to different heart chambers to diagnose and treat many different types of cardiac arrhythmias. The catheter typically includes a handle20, having suitable controls on the handle to enable the operator16to steer, position and orient the distal end15of the catheter as desired for the ablation. Ablation energy and electrical signals can be conveyed to and from the heart12through one or more electrodes32located at or near the tip18, or comprising tip18, via cable38to the console24. Pacing signals and other control signals may be conveyed from the console24through the cable38and the electrodes32to the heart12. Wire connections35link the console24with body surface electrodes30and other components of a positioning sub-system for measuring location and orientation coordinates of the catheter. The processor22or another processor may be an element of the positioning subsystem. The electrodes32and the body surface electrodes30may be used to measure tissue impedance at the ablation site as taught in U.S. Pat. No. 7,536,218, issued to Govari et al., which is herein incorporated by reference in its entirety. At least one temperature sensor, typically a thermocouple or thermistor, may be included on or near each of the electrodes32, as will be detailed below. The console24typically contains one or more ablation power generators25. The catheter may be adapted to conduct ablative energy to the heart using any known ablation technique, e.g., radiofrequency energy, ultrasound energy, cryogenic energy, and laser-produced light energy. Such methods are disclosed in commonly assigned U.S. Pat. Nos. 6,814,733, 6,997,924, and 7,156,816, which are herein incorporated by reference in their entirety. The positioning subsystem may also include a magnetic position tracking arrangement that determines the position and orientation of the catheter by generating magnetic fields in a predefined working volume and sensing these fields at the catheter, using coils or traces disposed within the catheter, typically proximate to the tip. A positioning subsystem is described in U.S. Pat. No. 7,756,576, which is hereby incorporated by reference in its entirety, and in the above-noted U.S. Pat. No. 7,536,218. Operator16may observe and regulate the functions of the catheter via console24. Console24includes a processor, preferably a computer with appropriate signal processing circuits. The processor is coupled to drive a monitor29. The signal processing circuits typically receive, amplify, filter and digitize signals from the catheter, including signals generated by sensors, e.g., electrodes32, such as electrical and temperature sensors, and a plurality of location sensing coils or traces located distally in the catheter. The digitized signals are received and used by the console24and the positioning system to compute the position and orientation of the catheter, and to analyze the electrical signals received from the catheter. The subject matter disclosed herein concerns improvements to fabrication and functionality of catheter tips known in the art, such as that disclosed in U.S. Pat. No. 6,171,275 to Webster, which is incorporated herein by reference in its entirety. The improved catheter tip may be fabricated via a lithographic process as a planar flexible circuit100reflected inFIGS.2-4. The flexible circuit100is, as its description suggests, flexible, meaning it can be bent into various non-planar configurations. For example, the configuration may be changed from planar to cylindrical, such that flexible circuit100may be changed into a cylindrical flexible-circuit flexible circuit200, reflected inFIG.5. Accordingly, apart from the planar configuration of flexible circuit100and the non-planar configuration of flexible circuit200, it should be understood that features described herein with respect to flexible circuit100are also present in flexible circuit200and, similarly, features described herein with respect to flexible circuit200are also present in flexible circuit100, even if express disclosure is not made concerning one of these configurations. Further, the surface of flexible circuit100visible inFIGS.2-4becomes flexible circuit200ofFIG.5. The surface of flexible circuit100visible inFIG.2becomes the inner surface of flexible circuit200. Flexible circuit100may include various segments depending on the desired structure of the flexible circuit200. As seen inFIG.2, flexible circuit100has a first segment102and a second segment104. First segment102may have a circular shape and second segment104may have a generally rectangular shape with one or more spaces along its upper edge adjoining segment102when in the planar configuration. Flexible circuit100may be formed into the flexible circuit200reflected inFIGS.5-6, with first segment102becoming the distal-most portion (base of the cylinder)202of flexible circuit200and with segment104becoming a lateral surface (wall of the cylinder)204of flexible circuit200. Segment102may be provided as having a rounded pattern (e.g., circular, elliptical or otherwise curved). Segment104may include a plurality of sections or sectors, such as first sector110, second sector112, and third sector114. Dashed lines113are provided on second segment104demarcating boundaries between these sectors. Each sector110,112,114can include a plurality of selectively positioned irrigation ports134to provide irrigation out of flexible circuit200. Ports134can be created in any manner of fabrication techniques (e.g., via laser drilling). Solder regions136,138and140may also be provided on second segment104, with region136on first sector110, region138on second sector112, and region140on third sector114, each having various contacts in conductive communication (operatively coupled) with the electronic componentry disposed on the corresponding sector. In some examples as depicted, region136can have six (6) contacts, region138can have five (5) contacts, while region140can have four (4) contacts. However, each region can have more or fewer contacts as needed or required In some examples, contacts of region136,138,140can be operatively coupled to thermocouples, and conductor elements of the system. In this manner, the electronic componentry on one of the three sectors110,112,114of second segment104may be controlled (e.g., for providing ablation or detecting electronic signals from tissue) and monitored separately (e.g., detecting separate temperatures for the separate temperature sensors disposed on each section of segment104) from the electronic componentry of the system. Further, temperatures may be precisely monitored about flexible circuit200because each of sectors110,112,114includes two distinct temperature sensors, for a total of six temperature sensors on flexible circuit200. In some examples, spacing may be provided between sectors110,112,114. The spacing may be provided through each layer, i.e., through the entire thickness of flexible circuit100. However, this spacing may be provided through only the layers comprising conductive materials and need not be provided in the substrate and insulating layers comprising non-conductive materials. This spacing may, for example, be provided along the contours identified by the lines113and can segregate the various sectors110,112, and114from each other, for example, helping to prevent distribution of heat from one sector to the other. Furthermore, sectors110,112,114can include portions109(seeFIG.4) that in flexible circuit200, are positioned in zone203adjacent the base202. In some examples, insulative materials may be disposed within the spacing. Turning toFIG.3, segment102comprises spaces108between pedals106radially positioned about segment102that can accommodate a transition zone203between base202and wall204. Ports134may further be provided through first segment102. Turning toFIG.4, a close-up of section B-B is showing segment104with spaces108between pedals106and lower tab111of respective sectors110and114. It is noted that sector112does not have a lower tab111since it comprises sectors110,114on both of its lateral side edges. Instead, sector112has two upper pedals106adjacent what will become transition zone203. Holes208may be provided in sectors110,112,114that are centrally positioned in the respective sector as well as positioned so that the electrode32of each respective sector110,112, and114can be arranged in both the transition zone203and wall204. Stated differently, sectors110,112,114collectively are structured to accommodate transition zone203between base202and wall204that includes upper portion32A of electrode32while lower portion32B is positioned in the wall204. In some examples, holes208may be positioned at least partially within both wall204and transition zone203. Holes208may accommodate various electronic components of the catheter, e.g., electrodes32. Previously described flexible circuit100may be formed into flexible circuit200shown inFIG.5and connected to distal end15of catheter body14, as shown inFIG.6. Catheter body14may be disposed longitudinally therethrough with at least two lumens. For example, one of the two lumens may be used to conduct irrigation fluid through catheter body14and into flexible circuit200. The other lumen may contain lead wires for conveying signals, e.g., electrical signals, to and from the electronic componentry of flexible circuit200. Additional lumens may be provided to, e.g., enable steering functionality, such as by including puller wires, or for a guide wire, as is known in the art. Flexible circuit200can be seen including sectors210,212, and214, each which correspond to the three sectors110,112, and114, respectively. Turning toFIG.6, upon forming flexible circuit100into flexible-circuit flexible circuit200, a space may be formed between first sector210and third sector214. This space may be filled with an insulating material for the spaces between first sector110and second sector112and between second sector112and third portion114. Catheter body14, outfitted with flexible circuit200thus provides various improvements in catheter tip design. Notably, rather than positioning microelectrodes on the lateral wall of flexible circuit200, electrodes32(including upper and lower portions32a,32b) are positioned in on the distal radius at least partially on the dome and later wall of flexible circuit200to optimize signal collection. In prior approaches, electrodes32being positioned only on the lateral wall204were discovered to be less likely to have direct contact with tissue in a perpendicular or diagonal contact with tissue due to electrode location. The herein disclosed solutions resolves this by maintaining conductivity while also optimizing the location of electrodes32. Moreover, the electrodes of flexible circuit200in one of sectors210,212,214can be activated or deactivated separately from the electrodes on each of the other sectors, and they can be activated to provide different functionality, e.g., ablation or ECG sensing. Further, the electrical signals, typically in the RF range of the generator, provided to each of the three sectors may be the same or different than the electrical signals provided to one or both of the others. That is, the power delivered to each tip sector (e.g., power amount denoted in Watts) can be the same or different for each of the sectors. For example, the power amount delivered to the first tip sector (“first power amount” in Watts) can be controlled to be different (i.e., higher or lower) than the power amount delivered to the second tip sector (“second power amount”). As well, the third tip sector can be turned off or a third power amount can be provided to the third tip sector (“third power amount”) that is different from the first power amount or the second power amount. Alternatively, energy delivered (in Joules) to each sector can be the same or different for each sector. In yet another example, the frequency of the RF signals provided to one sector may be varied relative to the frequency of the signals provided to one sector or both other sectors. The RF signals may be varied to any frequency within the RF frequency band of 10 kHZ to 1 MHz, e.g., based on suitable feedback controls. Such techniques to control energy or power to the tip sectors assist in controlling the temperature of flexible circuit200or tissue being ablated, and may further assist in improving the precision of the ablation. FIG.7reflects an alternative flexible circuit300that may be employed within a catheter, such as catheter14, to provide signals concerning location and force to a processor in console24. Flexible circuit300includes a substantially planar substrate with a first segment302and a second segment304. First segment302may be positioned at or adjacent the transition zone and base sections of flexible circuit300and be formed with one or more angled edges that meet at an apex to form a triangular shaped distal end of flexible circuit300, similar to the function of previously described segment102. Rather than having a central cap area of segment102of flexible circuit100, flexible circuit300has three (3) sectors310,312,314that form sections of a pie with overlapping tabs. In particular, segment304, similar to prior segment104, can be formed into a lateral wall of the non-planar tip associated with flexible circuit300. Segment304may include a plurality of sections or sectors, such as first sector310, second sector312, and third sector314. Dashed lines313are provided on second segment304demarcating boundaries between these sectors. Similar to flexible circuit100, solder regions336,338and340may also be provided with second segment304. Also similar to segment104, segment304comprises spaces308between pedals306,307positioned in the transition zone as well as adjacent the upper most tab307end at the flexible electrode300(i.e. top of the triangular shaped point) and lower tab311of respective sectors310and312. It is noted that sectors312and314do not have lower tabs311. Instead, sector312has two upper pedals306adjacent what will become transition zone303along with a single pedal that wraps around the upper most apex of sector312and extends partially down each adjoining edge extended from said apex. Between tabs306,309of sector312it can be seen that space308is provided. Sectors310,312,314, similar to those of flexible circuit100, may have holes associated with each electrode that are centrally positioned in the respective sector as well as positioned so that the electrode32of each respective sector310,312,314can be arranged in both the transition zone303and wall once in the nonplanar configuration. Stated differently, sectors310,312,314collectively are structured to accommodate transition zone303between the base and lateral side wall of the flexible circuit. In some examples, holes associated with electrodes32may be positioned at least partially within the lateral side wall and transition zone. FIG.8reflects an alternative flexible circuit400that may be employed within a catheter, such as catheter14, to provide signals concerning location and force to a processor in console24. Flexible circuit400includes another substantially planar substrate with a first segment402and a second segment404that includes a plurality of petal sectors410,412,414. First segment402, similar to segment102, may have a circular shape while being positioned at or adjacent the transition zone and base sections of flexible circuit400. Segment402may be provided as having a rounded pattern (e.g., circular, elliptical or otherwise curved). Segment402being centrally positioned with its curved shape acts as a central punch with segment404having its petal sectors410,412,414that fold proximally to form the distal radii and cylinder walls of flexible circuit400when in the nonplanar configuration. Segment404form the lateral wall of the non-planar flexible circuit associated with flexible circuit400and extend outward from segment402. Petal sectors410,412,414can be seen radially separated about segment402. In some examples, sectors410,412,414are equally spaced as shown with space408. Spaces408can be positioned adjacent the transition zone403as well as adjacent segment402. Dashed boundary lines413are provided inFIG.8strictly to depict the demarcation between segment402and sectors410,412,414, about which each sectors410,412,414can be folded and then attached together to form the walls and base of the nonplanar flexible circuit associated with flexible circuit400. Similar to flexible circuits100,300, solder regions436,438and440may also be provided with at the bottom edge of sectors410,412,414, respectively. Sectors410,412,414, similar to those of flexible circuits100,300, may have holes associated with each electrode that are centrally positioned in the respective sector as well as positioned so that the electrode32of each respective sector410,412,414can be arranged in both the transition zone403and wall once in the nonplanar configuration. Substrates used to form the flexible circuits described in this disclosure may be a single layer. Alternatively, it may include between two and ten layers, e.g., four layers. Each layer is identical to the others, including the shapes of the various portions and segments described above. However, thickening by layers results in increased non-linearity of signal yield. An advantage that a thinner substrate (e.g., four layers) has over a thicker substrate (e.g., eight layers) is that it is easier to deform or bend, which is helpful for assembling flexible circuit to other catheter components and ultimately for fitting it within the inner-diameter envelope of the catheter, as will be detailed below. It is noted that the make-up of biological tissue (e.g., water content, thickness or other tissue characteristics) in contact with a flexible circuit sector can affect the resistivity and therefore the RF power being delivered by that flexible circuit sector to the tissue. As such, the amount of temperature rise in that flexible circuit sector due to the energy or power delivered to such tissue can be different from other flexible circuit sectors in contact with the same tissue at different locations with correspondingly different tissues characteristics (or even different tissues). Therefore, one advantage of the embodiments herein is the ability for the system to deliver different power levels to different flexible circuit sectors to ensure that the temperature measured for one flexible circuit sector is generally the same for all of the flexible circuit sectors. Flexible circuit200(or300or400) may be brought into contact with tissue such that the tissue contacts at least a portion of the first sector, or at least a portion of the first sector and at least a portion of a second sector, or at least a portion of each of the three sectors. ECG signals may be separately assessed by the various electrodes of the three sectors such that the user or the system can determine which sectors contact tissue to determine which electrodes to activate to ablate. Further, the sector-specific signals of ECG may be used to tailor the therapy. For example, while sector210, operating as an electrode such as an ablation electrode, a sensor electrode, and/or a recording electrode, provides energy to tissue that sector210(or at least a portion thereof) contacts, the temperature sensors on sector210can measure and provide temperature data to processor22. Simultaneously, some or all of the temperature sensors on flexible circuit200may provide temperature data to processor22, while sectors212and214, operating as electromagnetic sensors and not in contact with tissue, in partial contact with tissue, or in full contact with tissue, may provide ECG data to processor22or may be deactivated. Alternatively, one of sectors212or214may be deactivated while the other provides ECG data. That is, while one or two sectors' electrodes function as ablation electrodes, the other electrodes can provide input to determine if additional areas should be ablated, and if so, how the therapy should be provided or tailored (e.g., via power modification, duration of activation, continuous or pulsed activations, etc.). Further, by providing ablation energy only to those sectors in contact with tissue, ablation energy may be precisely provided directly to tissue such that energy applied to blood may be minimized, which minimizes the likelihood of thrombus formation. In addition, with a smaller area of the anatomy (e.g., epicardial or renal) directly receiving the energy, there will be a higher probability that the errant tissue will be ablated faster and more accurately. Further, the ECG data from non-tissue contacting sector(s) may be used to check for early signs of blockages (e.g., thrombi), while tissue-contacting sector(s) in contact with tissue are being ablated, such that remedial steps may be promptly taken. Additionally, in certain instances, e.g., when at least a portion of sectors of a flexible circuit (e.g.,210,212,214) is determined to be in contact with tissue, processor22may control the application of ablation energy, either automatically or based on user input, such that the ablation energy may be provided to tissue via all three sectors simultaneously or in succession. When the ablation energy is applied in succession to more than one electrode, the ablation electrodes may be activated one at a time or two at a time. Two exemplary in-succession activations include: 1) sector210may be activated then deactivate, then sector212may be activated then deactivated, and sector214may be activated then deactivated; and 2) sectors210and212may be activated, then sector210may be deactivated and sector214activated, then sector212may be deactivated and sector210activated. Additional in-succession activations in differing combinations may be performed and also repeated until the desired ablation is achieved, as indicated by ECG signals or other signals provided by the electrode. One advantage of in-succession activations is that it permits different portions of tissue to be ablated and monitored without moving the catheter. Further, in-succession activations may be combined with simultaneous activations of all of the sectors. Moreover, the activations, whether in sequence or simultaneous, may be performed repeatedly. FIG.9is a flow diagram illustrating an example method900for assembling a catheter. The method900can include step910changing a planar configuration of any flexible circuit of this disclosure to a non-planar configuration. Step920can include connecting a proximal end opposite the base section of the second segment of the flexible circuit in the non-planar configuration to a distal end of an elongate catheter body. FIG.10is a flow diagram illustrating an example method1000of ablating tissue. The method1000can include step1010inserting any catheter according to this disclosure into a subject. Step1020can include contacting the flexible circuit of the catheter to cardiac tissue. Step1030can include ablating, with the flexible circuit, tissue. In some epicardial applications, certain design considerations may suggest further minimizing heat generated by one sector from being detected by a thermocouple of another sector, and further minimizing the likelihood that ECG signals detected by an electrode on one sector are also detected by a sensor of another sector. Accordingly, one or two of the three sectors may be fabricated with greater insulation properties but without other functions, such as temperature measurement, ablation, and sensing, and associated componentry, such as thermocouples and electrodes. Accordingly, one or two of the sectors, e.g., sector212, sector214, or both, may have a greater amount of insulation material incorporated therein than in those embodiments where these sectors include functions of, e.g., ablation. Thus, for example, a ceramic material may be deposited onto flexible circuit100over sectors112and114, which assists in preventing heat from ablated tissue from affecting the catheter tip via these sectors. As noted above, ECG signals may be separately assessed by electrodes disposed on the flexible circuit such that the user or the system can determine that the flexible circuit contacts tissue, and, in those embodiments with electrodes on different flexible circuit sectors, to determine which electrodes to activate for providing ablation therapy. Contact with tissue may also be determined using force contact sensors, e.g., as described in U.S. patent application Ser. No. 15/452,843, filed Mar. 8, 2017, which is incorporated by reference herein in its entirety. A contact force sensor particularly suited for use in a catheter having a split tip is now described, and also described in U.S. patent application Ser. No. 16/036,710, filed Jul. 16, 2018, and incorporated by reference herein in its entirety. The flexible circuit, in any of the foregoing embodiments, may be included on a distal end of a catheter. The catheter may also include an elongate body having at least two lumens disposed longitudinally therethrough. A core may be attached to the distal end of the catheter, at least a portion of which may be disposed within the second segment of the flexible circuit. The core may comprise an insulative material, such as polyurethane. Further, the core may include a lumen oriented transverse to a longitudinal axis of the core. A second insulation material may be disposed between the second segment and the core. The core may be in communication with a first one of the at least two lumens of the catheter body such that fluid may flow through one of the lumens and through the core. A plurality of wires may be disposed within at least a second one of the at least two lumens and this plurality of wires may be electrically connected to the flexible-circuit. The catheter may be used according to the following method and variations. First, the catheter may be inserted into a subject, e.g., a human subject, proximate to the subject's heart. The flexible circuit may be maneuvered into contact with the tissue. The catheter may be an aspect of an ablation system that also includes a processor that is in communication with the flexible circuit. The first sector may monitor an ECG signal and provide the signal to the processor. The second sector may monitor an ECG signal and provide the signal to the processor. The third sector may monitor an ECG signal and provide the signal to the processor. Each of the three sectors may also measure temperature and provide temperature data to the processor. Ablation energy may be provided to the flexible circuit, e.g., as controlled by the processor. An electrode can be included with the flexible circuit having at least one flexible printed circuit board (PCB) that is bonded, by an adhesive, to a supporting metallic sheet. The flexible PCB comprises a flexible thermally-insulating substrate comprising an outer surface that is coated by an outer layer of an electrically-conducting (and biocompatible) metal, such as gold, palladium, or platinum, and an inner surface that is coated by an inner layer of the same (and/or another) thermally-conducting metal. The inner surface may further support one or more electric components such as sensors (e.g., thermocouples) and traces, which are electrically isolated from the inner thermally-conducting layer. Following the deposition of the electric components, the coating of the substrate, and the bonding of the PCB to the supporting sheet, the flexible PCB (together with the supporting sheet) may be deformed into any suitable shape.

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Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate various disclosed aspects, in one form, and such exemplifications are not to be construed as limiting the scope thereof in any manner.Applicant of the present application owns the following U.S. Patent Applications filed on Mar. 30, 2021, the disclosure of each of which is herein incorporated by reference in its entirety:U.S. patent application Ser. No. 17/217,394, titled METHOD FOR MECHANICAL PACKAGING FOR MODULAR ENERGY SYSTEM, now U.S. Patent Application Publication No. 2022/0322523;U.S. patent application Ser. No. 17/217,4021, titled BACKPLANE CONNECTOR ATTACHMENT MECHANISM FOR MODULAR ENERGY SYSTEM, now U.S. Patent Application Publication No. 2022/0317750;U.S. patent application Ser. No. 17/217,446, titled HEADER FOR MODULAR ENERGY SYSTEM, now U.S. Patent Application Publication No. 2022/0313342;U.S. patent application Ser. No. 17/217,403, titled SURGICAL PROCEDURALIZATION VIA MODULAR ENERGY SYSTEM, nowU.S. Patent Application Publication No. 2022/0313341:U.S. patent application Ser. No. 17/217,424, titled METHOD FOR ENERGY DELIVERY FOR MODULAR ENERGY SYSTEM, now U.S. Patent Application Publication No. 2022/0317751;U.S. patent application Ser. No. 17/217,439, titled MODULAR ENERGY SYSTEM WITH DUAL AMPLIFIERS AND TECHNIQUES FOR UPDATING PARAMETERS THEREOF, now U.S. Patent Application Publication No. 2022/0321059;U.S. patent application Ser. No. 14/217,471, titled MODULAR ENERGY SYSTEM WITH MULTI-ENERGY PORT SPLITTER FOR MULTIPLE ENERGY DEVICES, now U.S. Patent Application Publication No. 2022/0313373.U.S. patent application Ser. No. 17/217,385, titled METHOD FOR INTELLIGENT INSTRUMENTS FOR MODULAR ENERGY SYSTEM, now U.S. Patent Application Publication No. 2022/0313369:U.S. patent application Ser. No. 17/217,392, titled RADIO FREQUENCY IDENTIFICATION TOKEN FOR WIRELESS SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2022/0319693;U.S. patent application Ser. No. 14/217,397, titled INTELLIGENT DATA PORTS FOR MODULAR ENERGY SYSTEMS, now U.S. Patent Application Publication No. 2022/0318179:U.S. patent application Ser. No. 17/217,405, titled METHOD FOR SYSTEM ARCHITECTURE FOR MODULAR ENERGY SYSTEM, now U.S. Patent Application Publication No. 2022/0313370;U.S. patent application Ser. No. 17/217,423, titled USER INTERFACE MITIGATION TECHNIQUES FOR MODULAR ENERGY SYSTEMS, now U.S. Patent Application Publication No. 2022/0313371;U.S. patent application Ser. No. 17/217,429, titled ENERGY DELIVERY MITIGATIONS FOR MODULAR ENERGY SYSTEMS, nowU.S. Patent Application Publication No. 2022/0313338;U.S. patent application Ser. No. 17/217,449, titled ARCHITECTURE FOR MODULAR ENERGY SYSTEM, now U.S. Patent Application Publication No. 2022/0313372; andU.S. patent application Ser. No. 17/217,461, titled MODULAR ENERGY SYSTEM WITH HARDWARE MITIGATED COMMUNICATION, now U.S. Patent Application Publication No. 2022/0319685. Applicant of the present application owns the following U.S. Patent Applications filed Sep. 5, 2019, the disclosure of each of which is herein incorporated by reference in its entirety:U.S. patent application Ser. No. 16/562,144, titled METHOD FOR CONTROLLING A MODULAR ENERGY SYSTEM USER INTERFACE, now U.S. Patent Application Publication No. 2020/0078106;U.S. patent application Ser. No. 16/562,151, titled PASSIVE HEADER MODULE FOR A MODULAR ENERGY SYSTEM, now U.S. Patent Application Publication No. 2020/0078110;U.S. patent application Ser. No. 16/562,157, titled CONSOLIDATED USER INTERFACE FOR MODULAR ENERGY SYSTEM, now U.S. Patent Application Publication No. 2020/0081585;U.S. patent application Ser. No. 16/562,159, titled AUDIO TONE CONSTRUCTION FOR AN ENERGY MODULE OF A MODULAR ENERGY SYSTEM, now U.S. Patent Application Publication No. 2020/0314569;U.S. patent application Ser. No. 16/562,163, titled ADAPTABLY CONNECTABLE AND REASSIGNABLE SYSTEM ACCESSORIES FOR MODULAR ENERGY SYSTEM, now U.S. Patent Application Publication No. 2020/0078111;U.S. patent application Ser. No. 16/562,123, titled METHOD FOR CONSTRUCTING AND USING A MODULAR SURGICAL ENERGY SYSTEM WITH MULTIPLE DEVICES, now U.S. Patent Application Publication No. 2020/0100830;U.S. patent application Ser. No. 16/562,135, titled METHOD FOR CONTROLLING AN ENERGY MODULE OUTPUT, now U.S. Patent Application Publication No. 2020/0078076;U.S. patent application Ser. No. 16/562,180, titled ENERGY MODULE FOR DRIVING MULTIPLE ENERGY MODALITIES, now U.S. Patent Application Publication No. 2020/0078080;U.S. patent application Ser. No. 16/562,184, titled GROUNDING ARRANGEMENT OF ENERGY MODULES, now U.S. Patent Application Publication No. 2020/0078081;U.S. patent application Ser. No. 16/562,188, titled BACKPLANE CONNECTOR DESIGN TO CONNECT STACKED ENERGY MODULES, now U.S. Patent Application Publication No. 2020/0078116;U.S. patent application Ser. No. 16/562,195, titled ENERGY MODULE FOR DRIVING MULTIPLE ENERGY MODALITIES THROUGH A PORT, now U.S. Patent Application Publication No. 20200078117;U.S. patent application Ser. No. 16/562,202 titled SURGICAL INSTRUMENT UTILIZING DRIVE SIGNAL TO POWER SECONDARY FUNCTION, now U.S. Patent Application Publication No. 2020/0078082;U.S. patent application Ser. No. 16/562,142, titled METHOD FOR ENERGY DISTRIBUTION IN A SURGICAL MODULAR ENERGY SYSTEM, now U.S. Patent Application Publication No. 2020/0078070;U.S. patent application Ser. No. 16/562,169, titled SURGICAL MODULAR ENERGY SYSTEM WITH A SEGMENTED BACKPLANE, now U.S. Patent Application Publication No. 2020/0078112;U.S. patent application Ser. No. 16/562,185, titled SURGICAL MODULAR ENERGY SYSTEM WITH FOOTER MODULE, now U.S. Patent Application Publication No. 2020/0078115;U.S. patent application Ser. No. 16/562,203, titled POWER AND COMMUNICATION MITIGATION ARRANGEMENT FOR MODULAR SURGICAL ENERGY SYSTEM, now U.S. Patent Application Publication No. 2020/0078118;U.S. patent application Ser. No. 16/562,212, titled MODULAR SURGICAL ENERGY SYSTEM WITH MODULE POSITIONAL AWARENESS SENSING WITH VOLTAGE DETECTION, now U.S. Patent Application Publication No. 2020/0078119;U.S. patent application Ser. No. 16/562,234, titled MODULAR SURGICAL ENERGY SYSTEM WITH MODULE POSITIONAL AWARENESS SENSING WITH TIME COUNTER, now U.S. Patent Application Publication No. 2020/0305945;U.S. patent application Ser. No. 16/562,243, titled MODULAR SURGICAL ENERGY SYSTEM WITH MODULE POSITIONAL AWARENESS WITH DIGITAL LOGIC, now U.S. Patent Application Publication No. 2020/0078120;U.S. patent application Ser. No. 16/562,125, titled METHOD FOR COMMUNICATING BETWEEN MODULES AND DEVICES IN A MODULAR SURGICAL SYSTEM, now U.S. Patent Application Publication No. 2020/0100825;U.S. patent application Ser. No. 16/562,137, titled FLEXIBLE HAND-SWITCH CIRCUIT, now U.S. Patent Application Publication No. 2020/0106220;U.S. patent application Ser. No. 16/562,143, titled FIRST AND SECOND COMMUNICATION PROTOCOL ARRANGEMENT FOR DRIVING PRIMARY AND SECONDARY DEVICES THROUGH A SINGLE PORT, now U.S. Patent Application Publication No. 2020/0090808;U.S. patent application Ser. No. 16/562,148, titled FLEXIBLE NEUTRAL ELECTRODE, now U.S. Patent Application Publication No. 2020/0078077;U.S. patent application Ser. No. 16/562,154, titled SMART RETURN PAD SENSING THROUGH MODULATION OF NEAR FIELD COMMUNICATION AND CONTACT QUALITY MONITORING SIGNALS, now U.S. Patent Application Publication No. 2020/0078089;U.S. patent application Ser. No. 16/562,162, titled AUTOMATIC ULTRASONIC ENERGY ACTIVATION CIRCUIT DESIGN FOR MODULAR SURGICAL SYSTEMS, now U.S. Patent Application Publication No. 2020/0305924;U.S. patent application Ser. No. 16/562,167, titled COORDINATED ENERGY OUTPUTS OF SEPARATE BUT CONNECTED MODULES, now U.S. Patent Application Publication No. 2020/0078078;U.S. patent application Ser. No. 16/562,170, titled MANAGING SIMULTANEOUS MONOPOLAR OUTPUTS USING DUTY CYCLE AND SYNCHRONIZATION, now U.S. Patent Application Publication No. 2020/0078079;U.S. patent application Ser. No. 16/562,172, titled PORT PRESENCE DETECTION SYSTEM FOR MODULAR ENERGY SYSTEM, now U.S. Patent Application Publication No. 2020/0078113;U.S. patent application Ser. No. 16/562,175, titled INSTRUMENT TRACKING ARRANGEMENT BASED ON REAL TIME CLOCK INFORMATION, now U.S. Patent Application Publication No. 2020/0078071;U.S. patent application Ser. No. 16/562,177, titled REGIONAL LOCATION TRACKING OF COMPONENTS OF A MODULAR ENERGY SYSTEM, now U.S. Patent Application Publication No. 2020/0078114;U.S. Design patent application Ser. No. 29/704,610, titled ENERGY MODULE;U.S. Design patent application Ser. No. 29/704,614, titled ENERGY MODULE MONOPOLAR PORT WITH FOURTH SOCKET AMONG THREE OTHER SOCKETS;U.S. Design patent application Ser. No. 29/704,616, titled BACKPLANE CONNECTOR FOR ENERGY MODULE; andU.S. Design patent application Ser. No. 29/704,617, titled ALERT SCREEN FOR ENERGY MODULE. Applicant of the present application owns the following U.S. Patent Provisional applications filed Mar. 29, 2019, the disclosure of each of which is herein incorporated by reference in its entirety:U.S. Provisional Patent Application Ser. No. 62/826,584, titled MODULAR SURGICAL PLATFORM ELECTRICAL ARCHITECTURE;U.S. Provisional Patent Application Ser. No. 62/826,587, titled MODULAR ENERGY SYSTEM CONNECTIVITY;U.S. Provisional Patent Application Ser. No. 62/826,588, titled MODULAR ENERGY SYSTEM INSTRUMENT COMMUNICATION TECHNIQUES; andU.S. Provisional Patent Application Ser. No. 62/826,592, titled MODULAR ENERGY DELIVERY SYSTEM. Applicant of the present application owns the following U.S. Patent Provisional application filed Sep. 7, 2018, the disclosure of each of which is herein incorporated by reference in its entirety:U.S. Provisional Patent Application Ser. No. 62/728,480, titled MODULAR ENERGY SYSTEM AND USER INTERFACE. Before explaining various aspects of surgical devices and generators in detail, it should be noted that the illustrative examples are not limited in application or use to the details of construction and arrangement of parts illustrated in the accompanying drawings and description. The illustrative examples may be implemented or incorporated in other aspects, variations and modifications, and may be practiced or carried out in various ways. Further, unless otherwise indicated, the terms and expressions employed herein have been chosen for the purpose of describing the illustrative examples for the convenience of the reader and are not for the purpose of limitation thereof. Also, it will be appreciated that one or more of the following-described aspects, expressions of aspects, and/or examples, can be combined with any one or more of the other following-described aspects, expressions of aspects and/or examples. Various aspects are directed to improved ultrasonic surgical devices, electrosurgical devices and generators for use therewith. Aspects of the ultrasonic surgical devices can be configured for transecting and/or coagulating tissue during surgical procedures, for example. Aspects of the electrosurgical devices can be configured for transecting, coagulating, scaling, welding and/or desiccating tissue during surgical procedures, for example. Surgical System Hardware Referring toFIG.1, a computer-implemented interactive surgical system100includes one or more surgical systems102and a cloud-based system (e.g., the cloud104that may include a remote server113coupled to a storage device105). Each surgical system102includes at least one surgical hub106in communication with the cloud104that may include a remote server113. In one example, as illustrated inFIG.1, the surgical system102includes a visualization system108, a robotic system110, and a handheld intelligent surgical instrument112, which are configured to communicate with one another and/or the hub106. In some aspects, a surgical system102may include an M number of hubs106, an N number of visualization systems108, an O number of robotic systems110, and a P number of handheld intelligent surgical instruments112, where M, N, O, and P are integers greater than or equal to one. FIG.2depicts an example of a surgical system102being used to perform a surgical procedure on a patient who is lying down on an operating table114in a surgical operating room116. A robotic system110is used in the surgical procedure as a part of the surgical system102. The robotic system110includes a surgeon's console118, a patient side cart120(surgical robot), and a surgical robotic hub122. The patient side cart120can manipulate at least one removably coupled surgical tool117through a minimally invasive incision in the body of the patient while the surgeon views the surgical site through the surgeon's console118. An image of the surgical site can be obtained by a medical imaging device124, which can be manipulated by the patient side cart120to orient the imaging device124. The robotic hub122can be used to process the images of the surgical site for subsequent display to the surgeon through the surgeon's console118. Other types of robotic systems can be readily adapted for use with the surgical system102. Various examples of robotic systems and surgical tools that are suitable for use with the present disclosure are described in U.S. Provisional Patent Application Ser. No. 62/611,339, titled ROBOT ASSISTED SURGICAL PLATFORM, filed Dec. 28, 2017, the disclosure of which is herein incorporated by reference in its entirety. Various examples of cloud-based analytics that are performed by the cloud104, and are suitable for use with the present disclosure, are described in U.S. Provisional Patent Application Ser. No. 62/611,340, titled CLOUD-BASED MEDICAL ANALYTICS, filed Dec. 28, 2017, the disclosure of which is herein incorporated by reference in its entirety. In various aspects, the imaging device124includes at least one image sensor and one or more optical components. Suitable image sensors include, but are not limited to, Charge-Coupled Device (CCD) sensors and Complementary Metal-Oxide Semiconductor (CMOS) sensors. The optical components of the imaging device124may include one or more illumination sources and/or one or more lenses. The one or more illumination sources may be directed to illuminate portions of the surgical field. The one or more image sensors may receive light reflected or refracted from the surgical field, including light reflected or refracted from tissue and/or surgical instruments. The one or more illumination sources may be configured to radiate electromagnetic energy in the visible spectrum as well as the invisible spectrum. The visible spectrum, sometimes referred to as the optical spectrum or luminous spectrum, is that portion of the electromagnetic spectrum that is visible to (i.e., can be detected by) the human eye and may be referred to as visible light or simply light. A typical human eye will respond to wavelengths in air that are from about 380 nm to about 750 nm. The invisible spectrum (i.e., the non-luminous spectrum) is that portion of the electromagnetic spectrum that lies below and above the visible spectrum (i.e., wavelengths below about 380 nm and above about 750 nm). The invisible spectrum is not detectable by the human eye. Wavelengths greater than about 750 nm are longer than the red visible spectrum, and they become invisible infrared (IR), microwave, and radio electromagnetic radiation. Wavelengths less than about 380 nm are shorter than the violet spectrum, and they become invisible ultraviolet, x-ray, and gamma ray electromagnetic radiation. In various aspects, the imaging device124is configured for use in a minimally invasive procedure. Examples of imaging devices suitable for use with the present disclosure include, but not limited to, an arthroscope, angioscope, bronchoscope, choledochoscope, colonoscope, cytoscope, duodenoscope, enteroscope, esophagogastro-duodenoscope (gastroscope), endoscope, laryngoscope, nasopharyngo-neproscope, sigmoidoscope, thoracoscope, and ureteroscope. In one aspect, the imaging device employs multi-spectrum monitoring to discriminate topography and underlying structures. A multi-spectral image is one that captures image data within specific wavelength ranges across the electromagnetic spectrum. The wavelengths may be separated by filters or by the use of instruments that are sensitive to particular wavelengths, including light from frequencies beyond the visible light range, e.g., IR and ultraviolet. Spectral imaging can allow extraction of additional information the human eye fails to capture with its receptors for red, green, and blue. The use of multi-spectral imaging is described in greater detail under the heading “Advanced Imaging Acquisition Module” in U.S. Provisional Patent Application Ser. No. 62/611,341, titled INTERACTIVE SURGICAL PLATFORM, filed Dec. 28, 2017, the disclosure of which is herein incorporated by reference in its entirety. Multi-spectrum monitoring can be a useful tool in relocating a surgical field after a surgical task is completed to perform one or more of the previously described tests on the treated tissue. It is axiomatic that strict sterilization of the operating room and surgical equipment is required during any surgery. The strict hygiene and sterilization conditions required in a “surgical theater,” i.e., an operating or treatment room, necessitate the highest possible sterility of all medical devices and equipment. Part of that sterilization process is the need to sterilize anything that comes in contact with the patient or penetrates the sterile field, including the imaging device124and its attachments and components. It will be appreciated that the sterile field may be considered a specified area, such as within a tray or on a sterile towel, that is considered free of microorganisms, or the sterile field may be considered an area, immediately around a patient, who has been prepared for a surgical procedure. The sterile field may include the scrubbed team members, who are properly attired, and all furniture and fixtures in the area. In various aspects, the visualization system108includes one or more imaging sensors, one or more image-processing units, one or more storage arrays, and one or more displays that are strategically arranged with respect to the sterile field, as illustrated inFIG.2. In one aspect, the visualization system108includes an interface for HL7, PACS, and EMR. Various components of the visualization system108are described under the heading “Advanced Imaging Acquisition Module” in U.S. Provisional Patent Application Ser. No. 62/611,341, titled INTERACTIVE SURGICAL PLATFORM, filed Dec. 28, 2017, the disclosure of which is herein incorporated by reference in its entirety. As illustrated inFIG.2, a primary display119is positioned in the sterile field to be visible to an operator at the operating table114. In addition, a visualization tower111is positioned outside the sterile field. The visualization tower111includes a first non-sterile display107and a second non-sterile display109, which face away from each other. The visualization system108, guided by the hub106, is configured to utilize the displays107,109, and119to coordinate information flow to operators inside and outside the sterile field. For example, the hub106may cause the visualization system108to display a snapshot of a surgical site, as recorded by an imaging device124, on a non-sterile display107or109, while maintaining a live feed of the surgical site on the primary display119. The snapshot on the non-sterile display107or109can permit a non-sterile operator to perform a diagnostic step relevant to the surgical procedure, for example. In one aspect, the hub106is also configured to route a diagnostic input or feedback entered by a non-sterile operator at the visualization tower111to the primary display119within the sterile field, where it can be viewed by a sterile operator at the operating table. In one example, the input can be in the form of a modification to the snapshot displayed on the non-sterile display107or109, which can be routed to the primary display119by the hub106. Referring toFIG.2, a surgical instrument112is being used in the surgical procedure as part of the surgical system102. The hub106is also configured to coordinate information flow to a display of the surgical instrument112. For example, in U.S. Provisional Patent Application Ser. No. 62/611,341, titled INTERACTIVE SURGICAL PLATFORM, filed Dec. 28, 2017, the disclosure of which is herein incorporated by reference in its entirety. A diagnostic input or feedback entered by a non-sterile operator at the visualization tower111can be routed by the hub106to the surgical instrument display115within the sterile field, where it can be viewed by the operator of the surgical instrument112. Example surgical instruments that are suitable for use with the surgical system102are described under the heading SURGICAL INSTRUMENT HARDWARE and in U.S. Provisional Patent Application Ser. No. 62/611,341, titled INTERACTIVE SURGICAL PLATFORM, filed Dec. 28, 2017, the disclosure of which is herein incorporated by reference in its entirety, for example. Referring now toFIG.3, a hub106is depicted in communication with a visualization system108, a robotic system110, and a handheld intelligent surgical instrument112. In some aspects, the visualization system108may be a separable piece of equipment. In alternative aspects, the visualization system108could be contained within the hub106as a functional module. The hub106includes a hub display135, an imaging module138, a generator module140, a communication module130, a processor module132, a storage array134, and an operating room mapping module133. In certain aspects, as illustrated inFIG.3, the hub106further includes a smoke evacuation module126, a suction/irrigation module128, and/or an insufflation module129. In certain aspects, any of the modules in the hub106may be combined with each other into a single module. During a surgical procedure, energy application to tissue, for sealing and/or cutting, is generally associated with smoke evacuation, suction of excess fluid, and/or irrigation of the tissue. Fluid, power, and/or data lines from different sources are often entangled during the surgical procedure. Valuable time can be lost addressing this issue during a surgical procedure. Detangling the lines may necessitate disconnecting the lines from their respective modules, which may require resetting the modules. The hub modular enclosure136offers a unified environment for managing the power, data, and fluid lines, which reduces the frequency of entanglement between such lines. Aspects of the present disclosure present a surgical hub for use in a surgical procedure that involves energy application to tissue at a surgical site. The surgical hub includes a hub enclosure and a combo generator module slidably receivable in a docking station of the hub enclosure. The docking station includes data and power contacts. The combo generator module includes one or more of an ultrasonic energy generator component, a bipolar RF energy generator component, and a monopolar RF energy generator component that are housed in a single unit. In one aspect, the combo generator module also includes a smoke evacuation component, at least one energy delivery cable for connecting the combo generator module to a surgical instrument, at least one smoke evacuation component configured to evacuate smoke, fluid, and/or particulates generated by the application of therapeutic energy to the tissue, and a fluid line extending from the remote surgical site to the smoke evacuation component. In one aspect, the fluid line is a first fluid line and a second fluid line extends from the remote surgical site to a suction and irrigation module slidably received in the hub enclosure. In one aspect, the hub enclosure comprises a fluid interface. Certain surgical procedures may require the application of more than one energy type to the tissue. One energy type may be more beneficial for cutting the tissue, while another different energy type may be more beneficial for sealing the tissue. For example, a bipolar generator can be used to seal the tissue while an ultrasonic generator can be used to cut the sealed tissue. Aspects of the present disclosure present a solution where a hub modular enclosure136is configured to accommodate different generators, and facilitate an interactive communication therebetween. One of the advantages of the hub modular enclosure136is enabling the quick removal and/or replacement of various modules. Aspects of the present disclosure present a modular surgical enclosure for use in a surgical procedure that involves energy application to tissue. The modular surgical enclosure includes a first energy-generator module, configured to generate a first energy for application to the tissue, and a first docking station comprising a first docking port that includes first data and power contacts. In one aspect, the first energy-generator module is slidably movable into an electrical engagement with the power and data contacts and wherein the first energy-generator module is slidably movable out of the electrical engagement with the first power and data contacts. In an alternative aspect, the first energy-generator module is stackably movable into an electrical engagement with the power and data contacts and wherein the first energy-generator module is stackably movable out of the electrical engagement with the first power and data contacts. Further to the above, the modular surgical enclosure also includes a second energy-generator module configured to generate a second energy, either the same or different than the first energy, for application to the tissue, and a second docking station comprising a second docking port that includes second data and power contacts. In one aspect, the second energy-generator module is slidably movable into an electrical engagement with the power and data contacts, and wherein the second energy-generator module is slidably movable out of the electrical engagement with the second power and data contacts. In an alternative aspect, the second energy-generator module is stackably movable into an electrical engagement with the power and data contacts, and wherein the second energy-generator module is stackably movable out of the electrical engagement with the second power and data contacts. In addition, the modular surgical enclosure also includes a communication bus between the first docking port and the second docking port, configured to facilitate communication between the first energy-generator module and the second energy-generator module. Referring toFIG.3, aspects of the present disclosure are presented for a hub modular enclosure136that allows the modular integration of a generator module140, a smoke evacuation module126, a suction/irrigation module128, and an insufflation module129. The hub modular enclosure136further facilitates interactive communication between the modules140,126,128,129. The generator module140can be a generator module with integrated monopolar, bipolar, and ultrasonic components supported in a single housing unit slidably insertable into the hub modular enclosure136. The generator module140can be configured to connect to a monopolar device142, a bipolar device144, and an ultrasonic device148. Alternatively, the generator module140may comprise a series of monopolar, bipolar, and/or ultrasonic generator modules that interact through the hub modular enclosure136. The hub modular enclosure136can be configured to facilitate the insertion of multiple generators and interactive communication between the generators docked into the hub modular enclosure136so that the generators would act as a single generator. In one aspect, the hub modular enclosure136comprises a modular power and communication backplane149with external and wireless communication headers to enable the removable attachment of the modules140,126,128,129and interactive communication therebetween. Generator Hardware As used throughout this description, the term “wireless” and its derivatives may be used to describe circuits, devices, systems, methods, techniques, communications channels, etc., that may communicate data through the use of modulated electromagnetic radiation through a non-solid medium. The term does not imply that the associated devices do not contain any wires, although in some aspects they might not. The communication module may implement any of a number of wireless or wired communication standards or protocols, including but not limited to Wi-Fi (IEEE 802.11 family), WiMAX (IEEE 802.16 family), IEEE 802.20, long term evolution (LTE), Ev-DO, HSPA+, HSDPA+, HSUPA+, EDGE, GSM, GPRS, CDMA, TDMA, DECT, Bluetooth, Ethernet derivatives thereof, as well as any other wireless and wired protocols that are designated as 3G, 4G, 5G, and beyond. The computing module may include a plurality of communication modules. For instance, a first communication module may be dedicated to shorter range wireless communications such as Wi-Fi and Bluetooth and a second communication module may be dedicated to longer range wireless communications such as GPS, EDGE, GPRS, CDMA, WiMAX, LTE, Ev-DO, and others. As used herein a processor or processing unit is an electronic circuit which performs operations on some external data source, usually memory or some other data stream. The term is used herein to refer to the central processor (central processing unit) in a system or computer systems (especially systems on a chip (SoCs)) that combine a number of specialized “processors.” As used herein, a system on a chip or system on chip (SoC or SOC) is an integrated circuit (also known as an “IC” or “chip”) that integrates all components of a computer or other electronic systems. It may contain digital, analog, mixed-signal, and often radio-frequency functions—all on a single substrate. A SoC integrates a microcontroller (or microprocessor) with advanced peripherals like graphics processing unit (GPU), Wi-Fi module, or coprocessor. A SoC may or may not contain built-in memory. As used herein, a microcontroller or controller is a system that integrates a microprocessor with peripheral circuits and memory. A microcontroller (or MCU for microcontroller unit) may be implemented as a small computer on a single integrated circuit. It may be similar to a SoC; a SoC may include a microcontroller as one of its components. A microcontroller may contain one or more core processing units (CPUs) along with memory and programmable input/output peripherals. Program memory in the form of Ferroelectric RAM, NOR flash or OTP ROM is also often included on chip, as well as a small amount of RAM. Microcontrollers may be employed for embedded applications, in contrast to the microprocessors used in personal computers or other general purpose applications consisting of various discrete chips. As used herein, the term controller or microcontroller may be a stand-alone IC or chip device that interfaces with a peripheral device. This may be a link between two parts of a computer or a controller on an external device that manages the operation of (and connection with) that device. Any of the processors or microcontrollers described herein, may be implemented by any single core or multicore processor such as those known under the trade name ARM Cortex by Texas Instruments. In one aspect, the processor may be an LM4F230H5QR ARM Cortex-M4F Processor Core, available from Texas Instruments, for example, comprising on-chip memory of 256 KB single-cycle flash memory, or other non-volatile memory, up to 40 MHz, a prefetch buffer to improve performance above 40 MHz, a 32 KB single-cycle serial random access memory (SRAM), internal read-only memory (ROM) loaded with StellarisWare® software, 2 KB electrically erasable programmable read-only memory (EEPROM), one or more pulse width modulation (PWM) modules, one or more quadrature encoder inputs (QEI) analog, one or more 12-bit Analog-to-Digital Converters (ADC) with 12 analog input channels, details of which are available for the product datasheet. In one aspect, the processor may comprise a safety controller comprising two controller-based families such as TMS570 and RM4x known under the trade name Hercules ARM Cortex R4, also by Texas Instruments. The safety controller may be configured specifically for IEC 61508 and ISO 26262 safety critical applications, among others, to provide advanced integrated safety features while delivering scalable performance, connectivity, and memory options. Modular devices include the modules (as described in connection withFIG.3, for example) that are receivable within a surgical hub and the surgical devices or instruments that can be connected to the various modules in order to connect or pair with the corresponding surgical hub. The modular devices include, for example, intelligent surgical instruments, medical imaging devices, suction/irrigation devices, smoke evacuators, energy generators, ventilators, insufflators, and displays. The modular devices described herein can be controlled by control algorithms. The control algorithms can be executed on the modular device itself, on the surgical hub to which the particular modular device is paired, or on both the modular device and the surgical hub (e.g., via a distributed computing architecture). In some exemplifications, the modular devices' control algorithms control the devices based on data sensed by the modular device itself (i.e., by sensors in, on, or connected to the modular device). This data can be related to the patient being operated on (e.g., tissue properties or insufflation pressure) or the modular device itself (e.g., the rate at which a knife is being advanced, motor current, or energy levels). For example, a control algorithm for a surgical stapling and cutting instrument can control the rate at which the instrument's motor drives its knife through tissue according to resistance encountered by the knife as it advances. FIG.4illustrates one form of a surgical system2200comprising a modular energy system2000and various surgical instruments2204,2206,2208usable therewith, where the surgical instrument2204is an ultrasonic surgical instrument, the surgical instrument2206is an RF electrosurgical instrument, and the multifunction surgical instrument2208is a combination ultrasonic/RF electrosurgical instrument. The modular energy system2000is configurable for use with a variety of surgical instruments. According to various forms, the modular energy system2000may be configurable for use with different surgical instruments of different types including, for example, ultrasonic surgical instruments2204, RF electrosurgical instruments2206, and multifunction surgical instruments2208that integrate RF and ultrasonic energies delivered individually or simultaneously from the modular energy system2000. Although in the form ofFIG.4the modular energy system2000is shown separate from the surgical instruments2204,2206,2208in one form, the modular energy system2000may be formed integrally with any of the surgical instruments2204,2206,2208to form a unitary surgical system. The modular energy system2000may be configured for wired or wireless communication. The modular energy system2000is configured to drive multiple surgical instruments2204,2206,2208. The first surgical instrument is an ultrasonic surgical instrument2204and comprises a handpiece2205(HP), an ultrasonic transducer2220, a shaft2226, and an end effector2222. The end effector2222comprises an ultrasonic blade2228acoustically coupled to the ultrasonic transducer2220and a clamp arm2240. The handpiece2205comprises a trigger2243to operate the clamp arm2240and a combination of the toggle buttons2234a,2234b,2234cto energize and drive the ultrasonic blade2228or other function. The toggle buttons2234a,2234b,2234ccan be configured to energize the ultrasonic transducer2220with the modular energy system2000. The modular energy system2000also is configured to drive a second surgical instrument2206. The second surgical instrument2206is an RF electrosurgical instrument and comprises a handpiece2207(HP), a shaft2227, and an end effector2224. The end effector2224comprises electrodes in clamp arms2242a,2242band return through an electrical conductor portion of the shaft2227. The electrodes are coupled to and energized by a bipolar energy source within the modular energy system2000. The handpiece2207comprises a trigger2245to operate the clamp arms2242a,2242band an energy button2235to actuate an energy switch to energize the electrodes in the end effector2224. The modular energy system2000also is configured to drive a multifunction surgical instrument2208. The multifunction surgical instrument2208comprises a handpiece2209(HP), a shaft2229, and an end effector2225. The end effector2225comprises an ultrasonic blade2249and a clamp arm2246. The ultrasonic blade2249is acoustically coupled to the ultrasonic transducer2220. The ultrasonic transducer2220may be separable from or integral to the handpiece2209. The handpiece2209comprises a trigger2247to operate the clamp arm2246and a combination of the toggle buttons2237a,2237b,2237cto energize and drive the ultrasonic blade2249or other function. The toggle buttons2237a,2237b,2237ccan be configured to energize the ultrasonic transducer2220with the modular energy system2000and energize the ultrasonic blade2249with a bipolar energy source also contained within the modular energy system2000. The modular energy system2000is configurable for use with a variety of surgical instruments. According to various forms, the modular energy system2000may be configurable for use with different surgical instruments of different types including, for example, the ultrasonic surgical instrument2204, the RF electrosurgical instrument2206, and the multifunction surgical instrument2208that integrates RF and ultrasonic energies delivered individually or simultaneously from the modular energy system2000. Although in the form ofFIG.4the modular energy system2000is shown separate from the surgical instruments2204,2206,2208, in another form the modular energy system2000may be formed integrally with any one of the surgical instruments2204,2206,2208to form a unitary surgical system. Further aspects of generators for digitally generating electrical signal waveforms and surgical instruments are described in U.S. Patent Application Publication No. 2017/0086914, which is herein incorporated by reference in its entirety. Situational Awareness Although an “intelligent” device including control algorithms that respond to sensed data can be an improvement over a “dumb” device that operates without accounting for sensed data, some sensed data can be incomplete or inconclusive when considered in isolation, i.e., without the context of the type of surgical procedure being performed or the type of tissue that is being operated on. Without knowing the procedural context (e.g., knowing the type of tissue being operated on or the type of procedure being performed), the control algorithm may control the modular device incorrectly or sub optimally given the particular context-free sensed data. For example, the optimal manner for a control algorithm to control a surgical instrument in response to a particular sensed parameter can vary according to the particular tissue type being operated on. This is due to the fact that different tissue types have different properties (e.g., resistance to tearing) and thus respond differently to actions taken by surgical instruments. Therefore, it may be desirable for a surgical instrument to take different actions even when the same measurement for a particular parameter is sensed. As one specific example, the optimal manner in which to control a surgical stapling and cutting instrument in response to the instrument sensing an unexpectedly high force to close its end effector will vary depending upon whether the tissue type is susceptible or resistant to tearing. For tissues that are susceptible to tearing, such as lung tissue, the instrument's control algorithm would optimally ramp down the motor in response to an unexpectedly high force to close to avoid tearing the tissue. For tissues that are resistant to tearing, such as stomach tissue, the instrument's control algorithm would optimally ramp up the motor in response to an unexpectedly high force to close to ensure that the end effector is clamped properly on the tissue. Without knowing whether lung or stomach tissue has been clamped, the control algorithm may make a suboptimal decision. One solution utilizes a surgical hub including a system that is configured to derive information about the surgical procedure being performed based on data received from various data sources and then control the paired modular devices accordingly. In other words, the surgical hub is configured to infer information about the surgical procedure from received data and then control the modular devices paired to the surgical hub based upon the inferred context of the surgical procedure.FIG.5illustrates a diagram of a situationally aware surgical system2300, in accordance with at least one aspect of the present disclosure. In some exemplifications, the data sources2326include, for example, the modular devices2302(which can include sensors configured to detect parameters associated with the patient and/or the modular device itself), databases2322(e.g., an EMR database containing patient records), and patient monitoring devices2324(e.g., a blood pressure (BP) monitor and an electrocardiography (EKG) monitor). The surgical hub2304can be configured to derive the contextual information pertaining to the surgical procedure from the data based upon, for example, the particular combination(s) of received data or the particular order in which the data is received from the data sources2326. The contextual information inferred from the received data can include, for example, the type of surgical procedure being performed, the particular step of the surgical procedure that the surgeon is performing, the type of tissue being operated on, or the body cavity that is the subject of the procedure. This ability by some aspects of the surgical hub2304to derive or infer information related to the surgical procedure from received data can be referred to as “situational awareness.” In one exemplification, the surgical hub2304can incorporate a situational awareness system, which is the hardware and/or programming associated with the surgical hub2304that derives contextual information pertaining to the surgical procedure from the received data. The situational awareness system of the surgical hub2304can be configured to derive the contextual information from the data received from the data sources2326in a variety of different ways. In one exemplification, the situational awareness system includes a pattern recognition system, or machine learning system (e.g., an artificial neural network), that has been trained on training data to correlate various inputs (e.g., data from databases2322, patient monitoring devices2324, and/or modular devices2302) to corresponding contextual information regarding a surgical procedure. In other words, a machine learning system can be trained to accurately derive contextual information regarding a surgical procedure from the provided inputs. In another exemplification, the situational awareness system can include a lookup table storing pre-characterized contextual information regarding a surgical procedure in association with one or more inputs (or ranges of inputs) corresponding to the contextual information. In response to a query with one or more inputs, the lookup table can return the corresponding contextual information for the situational awareness system for controlling the modular devices2302. In one exemplification, the contextual information received by the situational awareness system of the surgical hub2304is associated with a particular control adjustment or set of control adjustments for one or more modular devices2302. In another exemplification, the situational awareness system includes a further machine learning system, lookup table, or other such system, which generates or retrieves one or more control adjustments for one or more modular devices2302when provided the contextual information as input. A surgical hub2304incorporating a situational awareness system provides a number of benefits for the surgical system2300. One benefit includes improving the interpretation of sensed and collected data, which would in turn improve the processing accuracy and/or the usage of the data during the course of a surgical procedure. To return to a previous example, a situationally aware surgical hub2304could determine what type of tissue was being operated on; therefore, when an unexpectedly high force to close the surgical instrument's end effector is detected, the situationally aware surgical hub2304could correctly ramp up or ramp down the motor of the surgical instrument for the type of tissue. As another example, the type of tissue being operated can affect the adjustments that are made to the compression rate and load thresholds of a surgical stapling and cutting instrument for a particular tissue gap measurement. A situationally aware surgical hub2304could infer whether a surgical procedure being performed is a thoracic or an abdominal procedure, allowing the surgical hub2304to determine whether the tissue clamped by an end effector of the surgical stapling and cutting instrument is lung (for a thoracic procedure) or stomach (for an abdominal procedure) tissue. The surgical hub2304could then adjust the compression rate and load thresholds of the surgical stapling and cutting instrument appropriately for the type of tissue. As yet another example, the type of body cavity being operated in during an insufflation procedure can affect the function of a smoke evacuator. A situationally aware surgical hub2304could determine whether the surgical site is under pressure (by determining that the surgical procedure is utilizing insufflation) and determine the procedure type. As a procedure type is generally performed in a specific body cavity, the surgical hub2304could then control the motor rate of the smoke evacuator appropriately for the body cavity being operated in. Thus, a situationally aware surgical hub2304could provide a consistent amount of smoke evacuation for both thoracic and abdominal procedures. As yet another example, the type of procedure being performed can affect the optimal energy level at which an ultrasonic surgical instrument or radio frequency (RF) electrosurgical instrument operates. Arthroscopic procedures, for example, require higher energy levels because the end effector of the ultrasonic surgical instrument or RF electrosurgical instrument is immersed in fluid. A situationally aware surgical hub2304could determine whether the surgical procedure is an arthroscopic procedure. The surgical hub2304could then adjust the RF power level or the ultrasonic amplitude of the generator (i.e., “energy level”) to compensate for the fluid filled environment. Relatedly, the type of tissue being operated on can affect the optimal energy level for an ultrasonic surgical instrument or RF electrosurgical instrument to operate at. A situationally aware surgical hub2304could determine what type of surgical procedure is being performed and then customize the energy level for the ultrasonic surgical instrument or RF electrosurgical instrument, respectively, according to the expected tissue profile for the surgical procedure. Furthermore, a situationally aware surgical hub2304can be configured to adjust the energy level for the ultrasonic surgical instrument or RF electrosurgical instrument throughout the course of a surgical procedure, rather than just on a procedure-by-procedure basis. A situationally aware surgical hub2304could determine what step of the surgical procedure is being performed or will subsequently be performed and then update the control algorithms for the generator and/or ultrasonic surgical instrument or RF electrosurgical instrument to set the energy level at a value appropriate for the expected tissue type according to the surgical procedure step. As yet another example, data can be drawn from additional data sources2326to improve the conclusions that the surgical hub2304draws from one data source2326. A situationally aware surgical hub2304could augment data that it receives from the modular devices2302with contextual information that it has built up regarding the surgical procedure from other data sources2326. For example, a situationally aware surgical hub2304can be configured to determine whether hemostasis has occurred (i.e., whether bleeding at a surgical site has stopped) according to video or image data received from a medical imaging device. However, in some cases the video or image data can be inconclusive. Therefore, in one exemplification, the surgical hub2304can be further configured to compare a physiologic measurement (e.g., blood pressure sensed by a BP monitor communicably connected to the surgical hub2304) with the visual or image data of hemostasis (e.g., from a medical imaging device124(FIG.2) communicably coupled to the surgical hub2304) to make a determination on the integrity of the staple line or tissue weld. In other words, the situational awareness system of the surgical hub2304can consider the physiological measurement data to provide additional context in analyzing the visualization data. The additional context can be useful when the visualization data may be inconclusive or incomplete on its own. Another benefit includes proactively and automatically controlling the paired modular devices2302according to the particular step of the surgical procedure that is being performed to reduce the number of times that medical personnel are required to interact with or control the surgical system2300during the course of a surgical procedure. For example, a situationally aware surgical hub2304could proactively activate the generator to which an RF electrosurgical instrument is connected if it determines that a subsequent step of the procedure requires the use of the instrument. Proactively activating the energy source allows the instrument to be ready for use a soon as the preceding step of the procedure is completed. As another example, a situationally aware surgical hub2304could determine whether the current or subsequent step of the surgical procedure requires a different view or degree of magnification on the display according to the feature(s) at the surgical site that the surgeon is expected to need to view. The surgical hub2304could then proactively change the displayed view (supplied by, e.g., a medical imaging device for the visualization system108) accordingly so that the display automatically adjusts throughout the surgical procedure. As yet another example, a situationally aware surgical hub2304could determine which step of the surgical procedure is being performed or will subsequently be performed and whether particular data or comparisons between data will be required for that step of the surgical procedure. The surgical hub2304can be configured to automatically call up data screens based upon the step of the surgical procedure being performed, without waiting for the surgeon to ask for the particular information. Another benefit includes checking for errors during the setup of the surgical procedure or during the course of the surgical procedure. For example, a situationally aware surgical hub2304could determine whether the operating theater is setup properly or optimally for the surgical procedure to be performed. The surgical hub2304can be configured to determine the type of surgical procedure being performed, retrieve the corresponding checklists, product location, or setup needs (e.g., from a memory), and then compare the current operating theater layout to the standard layout for the type of surgical procedure that the surgical hub2304determines is being performed. In one exemplification, the surgical hub2304can be configured to compare the list of items for the procedure (scanned by a scanner, for example) and/or a list of devices paired with the surgical hub2304to a recommended or anticipated manifest of items and/or devices for the given surgical procedure. If there are any discontinuities between the lists, the surgical hub2304can be configured to provide an alert indicating that a particular modular device2302, patient monitoring device2324, and/or other surgical item is missing. In one exemplification, the surgical hub2304can be configured to determine the relative distance or position of the modular devices2302and patient monitoring devices2324via proximity sensors, for example. The surgical hub2304can compare the relative positions of the devices to a recommended or anticipated layout for the particular surgical procedure. If there are any discontinuities between the layouts, the surgical hub2304can be configured to provide an alert indicating that the current layout for the surgical procedure deviates from the recommended layout. As another example, a situationally aware surgical hub2304could determine whether the surgeon (or other medical personnel) was making an error or otherwise deviating from the expected course of action during the course of a surgical procedure. For example, the surgical hub2304can be configured to determine the type of surgical procedure being performed, retrieve the corresponding list of steps or order of equipment usage (e.g., from a memory), and then compare the steps being performed or the equipment being used during the course of the surgical procedure to the expected steps or equipment for the type of surgical procedure that the surgical hub2304determined is being performed. In one exemplification, the surgical hub2304can be configured to provide an alert indicating that an unexpected action is being performed or an unexpected device is being utilized at the particular step in the surgical procedure. Overall, the situational awareness system for the surgical hub2304improves surgical procedure outcomes by adjusting the surgical instruments (and other modular devices2302) for the particular context of each surgical procedure (such as adjusting to different tissue types) and validating actions during a surgical procedure. The situational awareness system also improves surgeons' efficiency in performing surgical procedures by automatically suggesting next steps, providing data, and adjusting displays and other modular devices2302in the surgical theater according to the specific context of the procedure. Modular Energy System ORs everywhere in the world are a tangled web of cords, devices, and people due to the amount of equipment required to perform surgical procedures. Surgical capital equipment tends to be a major contributor to this issue because most surgical capital equipment performs a single, specialized task. Due to their specialized nature and the surgeons' needs to utilize multiple different types of devices during the course of a single surgical procedure, an OR may be forced to be stocked with two or even more pieces of surgical capital equipment, such as energy generators. Each of these pieces of surgical capital equipment must be individually plugged into a power source and may be connected to one or more other devices that are being passed between OR personnel, creating a tangle of cords that must be navigated. Another issue faced in modern ORs is that each of these specialized pieces of surgical capital equipment has its own user interface and must be independently controlled from the other pieces of equipment within the OR. This creates complexity in properly controlling multiple different devices in connection with each other and forces users to be trained on and memorize different types of user interfaces (which may further change based upon the task or surgical procedure being performed, in addition to changing between each piece of capital equipment). This cumbersome, complex process can necessitate the need for even more individuals to be present within the OR and can create danger if multiple devices are not properly controlled in tandem with each other. Therefore, consolidating surgical capital equipment technology into singular systems that are able to flexibly address surgeons' needs to reduce the footprint of surgical capital equipment within ORs would simplify the user experience, reduce the amount of clutter in ORs, and prevent difficulties and dangers associated with simultaneously controlling multiple pieces of capital equipment. Further, making such systems expandable or customizable would allow for new technology to be conveniently incorporated into existing surgical systems, obviating the need to replace entire surgical systems or for OR personnel to learn new user interfaces or equipment controls with each new technology. As described inFIGS.1-3, a surgical hub106can be configured to interchangeably receive a variety of modules, which can in turn interface with surgical devices (e.g., a surgical instrument or a smoke evacuator) or provide various other functions (e.g., communications). In one aspect, a surgical hub106can be embodied as a modular energy system2000, which is illustrated in connection withFIGS.6-12. The modular energy system2000can include a variety of different modules2001that are connectable together in a stacked configuration. In one aspect, the modules2001can be both physically and communicably coupled together when stacked or otherwise connected together into a singular assembly. Further, the modules2001can be interchangeably connectable together in different combinations or arrangements. In one aspect, each of the modules2001can include a consistent or universal array of connectors disposed along their upper and lower surfaces, thereby allowing any module2001to be connected to another module2001in any arrangement (except that, in some aspects, a particular module type, such as the header module2002, can be configured to serve as the uppermost module within the stack, for example). In an alternative aspect, the modular energy system2000can include a housing that is configured to receive and retain the modules2001, as is shown inFIG.3. The modular energy system2000can also include a variety of different components or accessories that are also connectable to or otherwise associatable with the modules2001. In another aspect, the modular energy system2000can be embodied as a generator module140(FIG.3) of a surgical hub106. In yet another aspect, the modular energy system2000can be a distinct system from a surgical hub106. In such aspects, the modular energy system2000can be communicably couplable to a surgical hub206for transmitting and/or receiving data therebetween. The modular energy system2000can be assembled from a variety of different modules2001, some examples of which are illustrated inFIG.6. Each of the different types of modules2001can provide different functionality, thereby allowing the modular energy system2000to be assembled into different configurations to customize the functions and capabilities of the modular energy system2000by customizing the modules2001that are included in each modular energy system2000. The modules2001of the modular energy system2000can include, for example, a header module2002(which can include a display screen2006), an energy module2004, a technology module2040, and a visualization module2042. In the depicted aspect, the header module2002is configured to serve as the top or uppermost module within the modular energy system stack and can thus lack connectors along its top surface. In another aspect, the header module2002can be configured to be positioned at the bottom or the lowermost module within the modular energy system stack and can thus lack connectors along its bottom surface. In yet another aspect, the header module2002can be configured to be positioned at an intermediate position within the modular energy system stack and can thus include connectors along both its bottom and top surfaces. The header module2002can be configured to control the system-wide settings of each module2001and component connected thereto through physical controls2011thereon and/or a graphical user interface (GUI)2008rendered on the display screen2006. Such settings could include the activation of the modular energy system2000, the volume of alerts, the footswitch settings, the settings icons, the appearance or configuration of the user interface, the surgeon profile logged into the modular energy system2000, and/or the type of surgical procedure being performed. The header module2002can also be configured to provide communications, processing, and/or power for the modules2001that are connected to the header module2002. The energy module2004, which can also be referred to as a generator module140(FIG.3), can be configured to generate one or multiple energy modalities for driving electrosurgical and/or ultrasonic surgical instruments connected thereto. The technology module2040can be configured to provide additional or expanded control algorithms (e.g., electrosurgical or ultrasonic control algorithms for controlling the energy output of the energy module2004). The visualization module2042can be configured to interface with visualization devices (i.e., scopes) and accordingly provide increased visualization capabilities. The modular energy system2000can further include a variety of accessories2029that are connectable to the modules2001for controlling the functions thereof or that are otherwise configured to work on conjunction with the modular energy system2000. The accessories2029can include, for example, a single-pedal footswitch2032, a dual-pedal footswitch2034, and a cart2030for supporting the modular energy system2000thereon. The footswitches2032,2034can be configured to control the activation or function of particular energy modalities output by the energy module2004, for example. By utilizing modular components, the depicted modular energy system2000provides a surgical platform that grows with the availability of technology and is customizable to the needs of the facility and/or surgeons. Further, the modular energy system2000supports combo devices (e.g., dual electrosurgical and ultrasonic energy generators) and supports software-driven algorithms for customized tissue effects. Still further, the surgical system architecture reduces the capital footprint by combining multiple technologies critical for surgery into a single system. The various modular components utilizable in connection with the modular energy system2000can include monopolar energy generators, bipolar energy generators, dual electrosurgical/ultrasonic energy generators, display screens, and various other modules and/or other components, some of which are also described above in connection withFIGS.1-3. Referring now toFIG.7A, the header module2002can, in some aspects, include a display screen2006that renders a GUI2008for relaying information regarding the modules2001connected to the header module2002. In some aspects, the GUI2008of the display screen2006can provide a consolidated point of control of all of the modules2001making up the particular configuration of the modular energy system2000. Various aspects of the GUI2008are discussed in fuller detail below in connection withFIG.12. In alternative aspects, the header module2002can lack the display screen2006or the display screen2006can be detachably connected to the housing2010of the header module2002. In such aspects, the header module2002can be communicably couplable to an external system that is configured to display the information generated by the modules2001of the modular energy system2000. For example, in robotic surgical applications, the modular energy system2000can be communicably couplable to a robotic cart or robotic control console, which is configured to display the information generated by the modular energy system2000to the operator of the robotic surgical system. As another example, the modular energy system2000can be communicably couplable to a mobile display that can be carried or secured to a surgical staff member for viewing thereby. In yet another example, the modular energy system2000can be communicably couplable to a surgical hub2100or another computer system that can include a display2104, as is illustrated inFIG.11. In aspects utilizing a user interface that is separate from or otherwise distinct from the modular energy system2000, the user interface can be wirelessly connectable with the modular energy system2000as a whole or one or more modules2001thereof such that the user interface can display information from the connected modules2001thereon. Referring still toFIG.7A, the energy module2004can include a port assembly2012including a number of different ports configured to deliver different energy modalities to corresponding surgical instruments that are connectable thereto. In the particular aspect illustrated inFIGS.6-12, the port assembly2012includes a bipolar port2014, a first monopolar port2016a, a second monopolar port2016b, a neutral electrode port2018(to which a monopolar return pad is connectable), and a combination energy port2020. However, this particular combination of ports is simply provided for illustrative purposes and alternative combinations of ports and/or energy modalities may be possible for the port assembly2012. As noted above, the modular energy system2000can be assembled into different configurations. Further, the different configurations of the modular energy system2000can also be utilizable for different surgical procedure types and/or different tasks. For example,FIGS.7A and7Billustrate a first illustrative configuration of the modular energy system2000including a header module2002(including a display screen2006) and an energy module2004connected together. Such a configuration can be suitable for laparoscopic and open surgical procedures, for example. FIG.8Aillustrates a second illustrative configuration of the modular energy system2000including a header module2002(including a display screen2006), a first energy module2004a, and a second energy module2004bconnected together. By stacking two energy modules2004a,2004b, the modular energy system2000can provide a pair of port assemblies2012a,2012bfor expanding the array of energy modalities deliverable by the modular energy system2000from the first configuration. The second configuration of the modular energy system2000can accordingly accommodate more than one bipolar/monopolar electrosurgical instrument, more than two bipolar/monopolar electrosurgical instruments, and so on. Such a configuration can be suitable for particularly complex laparoscopic and open surgical procedures.FIG.8Billustrates a third illustrative configuration that is similar to the second configuration, except that the header module2002lacks a display screen2006. This configuration can be suitable for robotic surgical applications or mobile display applications, as noted above. FIG.9illustrates a fourth illustrative configuration of the modular energy system2000including a header module2002(including a display screen2006), a first energy module2004a, a second energy module2004b, and a technology module2040connected together. Such a configuration can be suitable for surgical applications where particularly complex or computation-intensive control algorithms are required. Alternatively, the technology module2040can be a newly released module that supplements or expands the capabilities of previously released modules (such as the energy module2004). FIG.10illustrates a fifth illustrative configuration of the modular energy system2000including a header module2002(including a display screen2006), a first energy module2004a, a second energy module2004b, a technology module2040, and a visualization module2042connected together. Such a configuration can be suitable for endoscopic procedures by providing a dedicated surgical display2044for relaying the video feed from the scope coupled to the visualization module2042. It should be noted that the configurations illustrated inFIGS.7A-11and described above are provided simply to illustrate the various concepts of the modular energy system2000and should not be interpreted to limit the modular energy system2000to the particular aforementioned configurations. As noted above, the modular energy system2000can be communicably couplable to an external system, such as a surgical hub2100as illustrated inFIG.11. Such external systems can include a display screen2104for displaying a visual feed from an endoscope (or a camera or another such visualization device) and/or data from the modular energy system2000. Such external systems can also include a computer system2102for performing calculations or otherwise analyzing data generated or provided by the modular energy system2000, controlling the functions or modes of the modular energy system2000, and/or relaying data to a cloud computing system or another computer system. Such external systems could also coordinate actions between multiple modular energy systems2000and/or other surgical systems (e.g., a visualization system108and/or a robotic system110as described in connection withFIGS.1and2). Referring now toFIG.12, in some aspects, the header module2002can include or support a display2006configured for displaying a GUI2008, as noted above. The display screen2006can include a touchscreen for receiving input from users in addition to displaying information. The controls displayed on the GUI2008can correspond to the module(s)2001that are connected to the header module2002. In some aspects, different portions or areas of the GUI2008can correspond to particular modules2001. For example, a first portion or area of the GUI2008can correspond to a first module and a second portion or area of the GUI2008can correspond to a second module. As different and/or additional modules2001are connected to the modular energy system stack, the GUI2008can adjust to accommodate the different and/or additional controls for each newly added module2001or remove controls for each module2001that is removed. Each portion of the display corresponding to a particular module connected to the header module2002can display controls, data, user prompts, and/or other information corresponding to that module. For example, inFIG.12, a first or upper portion2052of the depicted GUI2008displays controls and data associated with an energy module2004that is connected to the header module2002. In particular, the first portion2052of the GUI2008for the energy module2004provides first widget2056acorresponding to the bipolar port2014, a second widget2056bcorresponding to the first monopolar port2016a, a third widget2056ccorresponding to the second monopolar port2016b, and a fourth widget2056dcorresponding to the combination energy port2020. Each of these widgets2056a-dprovides data related to its corresponding port of the port assembly2012and controls for controlling the modes and other features of the energy modality delivered by the energy module2004through the respective port of the port assembly2012. For example, the widgets2056a—d can be configured to display the power level of the surgical instrument connected to the respective port, change the operational mode of the surgical instrument connected to the respective port (e.g., change a surgical instrument from a first power level to a second power level and/or change a monopolar surgical instrument from a “spray” mode to a “blend” mode), and so on. In one aspect, the header module2002can include various physical controls2011in addition to or in lieu of the GUI2008. Such physical controls2011can include, for example, a power button that controls the application of power to each module2001that is connected to the header module2002in the modular energy system2000. Alternatively, the power button can be displayed as part of the GUI2008. Therefore, the header module2002can serve as a single point of contact and obviate the need to individually activate and deactivate each individual module2001from which the modular energy system2000is constructed. In one aspect, the header module2002can display still images, videos, animations, and/or information associated with the surgical modules2001of which the modular energy system2000is constructed or the surgical devices that are communicably coupled to the modular energy system2000. The still images and/or videos displayed by the header module2002can be received from an endoscope or another visualization device that is communicably coupled to the modular energy system2000. The animations and/or information of the GUI2008can be overlaid on or displayed adjacent to the images or video feed. In one aspect, the modules2001other than the header module2002can be configured to likewise relay information to users. For example, the energy module2004can include light assemblies2015disposed about each of the ports of the port assembly2012. The light assemblies2015can be configured to relay information to the user regarding the port according to their color or state (e.g., flashing). For example, the light assemblies2015can change from a first color to a second color when a plug is fully seated within the respective port. In one aspect, the color or state of the light assemblies2015can be controlled by the header module2002. For example, the header module2002can cause the light assembly2015of each port to display a color corresponding to the color display for the port on the GUI2008. FIG.13is a block diagram of a stand-alone hub configuration of a modular energy system3000, in accordance with at least one aspect of the present disclosure andFIG.14is a block diagram of a hub configuration of a modular energy system3000integrated with a surgical control system3010, in accordance with at least one aspect of the present disclosure. As depicted inFIGS.13and14, the modular energy system3000can be either utilized as stand-alone units or integrated with a surgical control system3010that controls and/or receives data from one or more surgical hub units. In the examples illustrated inFIGS.13and14, the integrated header/UI module3002of the modular energy system3000includes a header module and a UI module integrated together as a singular module. In other aspects, the header module and the UI module can be provided as separate components that are communicatively coupled though a data bus3008. As illustrated inFIG.13, an example of a stand-alone modular energy system3000includes an integrated header module/user interface (UI) module3002coupled to an energy module3004. Power and data are transmitted between the integrated header/UI module3002and the energy module3004through a power interface3006and a data interface3008. For example, the integrated header/UI module3002can transmit various commands to the energy module3004through the data interface3008. Such commands can be based on user inputs from the UI. As a further example, power may be transmitted to the energy module3004through the power interface3006. InFIG.14, a surgical hub configuration includes a modular energy system3000integrated with a control system3010and an interface system3022for managing, among other things, data and power transmission to and/or from the modular energy system3000. The modular energy system depicted inFIG.14includes an integrated header module/UI module3002, a first energy module3004, and a second energy module3012. In one example, a data transmission pathway is established between the system control unit3024of the control system3010and the second energy module3012through the first energy module3004and the header/UI module3002through a data interface3008. In addition, a power pathway extends between the integrated header/UI module3002and the second energy module3012through the first energy module3004through a power interface3006. In other words, in one aspect, the first energy module3004is configured to function as a power and data interface between the second energy module3012and the integrated header/UI module3002through the power interface3006and the data interface3008. This arrangement allows the modular energy system3000to expand by seamlessly connecting additional energy modules to energy modules3004,3012that are already connected to the integrated header/UI module3002without the need for dedicated power and energy interfaces within the integrated header/UI module3002. The system control unit3024, which may be referred to herein as a control circuit, control logic, microprocessor, microcontroller, logic, or FPGA, or various combinations thereof, is coupled to the system interface3022via energy interface3026and instrument communication interface3028. The system interface3022is coupled to the first energy module3004via a first energy interface3014and a first instrument communication interface3016. The system interface3022is coupled to the second energy module3012via a second energy interface3018and a second instrument communication interface3020. As additional modules, such as additional energy modules, are stacked in the modular energy system3000, additional energy and communications interfaces are provided between the system interface3022and the additional modules. The energy modules3004,3012are connectable to a hub and can be configured to generate electrosurgical energy (e.g., bipolar or monopolar), ultrasonic energy, or a combination thereof (referred to herein as an “advanced energy” module) for a variety of energy surgical instruments. Generally, the energy modules3004,3012include hardware/software interfaces, an ultrasonic controller, an advanced energy RF controller, bipolar RF controller, and control algorithms executed by the controller that receives outputs from the controller and controls the operation of the various energy modules3004,3012accordingly. In various aspects of the present disclosure, the controllers described herein may be implemented as a control circuit, control logic, microprocessor, microcontroller, logic, or FPGA, or various combinations thereof. In one aspect, with reference toFIGS.13and14, the modules of the modular energy system3000can include an optical link allowing high speed communication (10-50 Mb/s) across the patient isolation boundary. This link would carry device communications, mitigation signals (watchdog, etc.), and low bandwidth run-time data. In some aspects, the optical link(s) will not contain real-time sampled data, which can be done on the non-isolated side. In one aspect, with reference toFIGS.13and14, the modules of the modular energy system3000can include a multi-function circuit block which can: (i) read presence resistor values via A/D and current source, (ii) communicate with legacy instruments via hand switch Q protocols, (iii) communicate with instruments via local bus 1-Wire protocols, and (iv) communicate with CAN FD-enabled surgical instruments. When a surgical instrument is properly identified by an energy generator module, the relevant pin functions and communications circuits are enabled, while the other unused functions are disabled or disconnected, and set to a high impedance state. In one aspect, with reference toFIGS.13and14, the modules of the modular energy system3000can include a pulse/stimulation/auxiliary amplifier. This is a flexible-use amplifier based on a full-bridge output and incorporates functional isolation. This allows its differential output to be referenced to any output connection on the applied part (except, in some aspects, a monopolar active electrode). The amplifier output can be either small signal linear (pulse/stim) with waveform drive provided by a DAC or a square wave drive at moderate output power for DC applications such as DC motors, illumination, FET drive, etc. The output voltage and current are sensed with functionally isolated voltage and current feedback to provide accurate impedance and power measurements to the FPGA. Paired with a CAN FD-enabled instrument, this output can offer motor/motion control drive, while position or velocity feedback is provided by the CAN FD interface for closed loop control. As described in greater detail herein, a modular energy system comprises a header module and one or more functional or surgical modules. In various instances, the modular energy system is a modular energy system. In various instances, the surgical modules include energy modules, communication modules, user interface modules; however, the surgical modules are envisioned to be any suitable type of functional or surgical module for use with the modular energy system. Modular energy system offers many advantages in a surgical procedure, as described above in connection with the modular energy systems2000(FIGS.6-12),3000(FIGS.13-15). However, cable management and setup/teardown time can be a significant deterrent. Various aspects of the present disclosure provide a modular energy system with a single power cable and a single power switch to control startup and shutdown of the entire modular energy system, which obviated the need to individually activate and deactivate each individual module from which the modular energy system is constructed. Also, various aspects of the present disclosure provide a modular energy system with power management schemes that facilitate a safe and, in some instances, concurrent delivery of power to the modules of a modular energy system. In various aspects, as illustrated inFIG.15, a modular energy system6000that is similar in many respects to the modular energy systems2000(FIGS.6-12),3000(FIGS.13-15). For the sake of brevity, various details of the modular energy system6000, which are similar to the modular energy system2000and/or the modular energy system3000, are not repeated herein. The modular energy system6000comprises a header module6002and an “N” number of surgical modules6004, where “N” is an integer greater than or equal to one. In various examples, the modular energy system6000includes a UI module such as, for example, the UI module3030and/or a communication module such as, for example, the communication module3032. Furthermore, pass-through hub connectors couple individual modules to one another in a stack configuration. In the example ofFIG.15, the header module6002is coupled to a surgical module6004via pass-through hub connectors6005,6006. The modular energy system6000comprises an example power architecture that consists of a single AC/DC power supply6003that provides power to all the surgical modules in the stack. The AC/DC power supply6003is housed in the header module6002, and utilizes a power backplane6008to distribute power to each module in the stack. The example ofFIG.15demonstrates three separate power domains on the power backplane6008: a primary power domain6009, a standby power domain6010, and an Ethernet switch power domain6013. In the example illustrated inFIG.15, the power backplane6008extends from the header module6002through a number of intermediate modules6004to a most bottom, or farthest, module in the stack. In various aspects, the power backplane6008is configured to deliver power to a surgical module6004through one or more other surgical modules6004that are ahead of it in the stack. The surgical module6004receiving power from the header module6002can be coupled to a surgical instrument or tool configured to deliver therapeutic energy to a patient. The primary power domain6009is the primary power source for the functional module-specific circuits6013,6014,6015of the modules6002,6004. It consists of a single voltage rail that is provided to every module. In at least one example, a nominal voltage of 60V can be selected to be higher than the local rails needed by any module, so that the modules can exclusively implement buck regulation, which is generally more efficient than boost regulation. In various aspects, the primary power domain6009is controlled by the header module6002. In certain instances, as illustrated inFIG.15, a local power switch6018is positioned on the header module6002. In certain instances, a remote on/off interface6016can be configured to control a system power control6017on the header module6002, for example. In at least one example, the remote on/off interface6016is configured to transmit pulsed discrete commands (separate commands for On and Off) and a power status telemetry signal. In various instances, the primary power domain6009is configured to distribute power to all the modules in the stack configuration following a user-initiated power-up. In various aspects, as illustrated inFIG.16, the modules of the modular energy system6000can be communicably coupled to the header module6002and/or to each other via a communication (Serial bus/Ethernet) interface6040such that data or other information is shared by and between the modules of which the modular energy system is constructed. An Ethernet switch domain6013can be derived from the primary power domain6009, for example. The Ethernet switch power domain6013is segregated into a separate power domain, which is configured to power Ethernet switches within each of the modules in the stack configuration, so that the primary communications interface6040will remain alive when local power to a module is removed. In at least one example, the primary communication interface6040comprises a 1000BASE-T Ethernet network, where each module represents a node on the network, and each module downstream from the header module6002contains a 3-port Ethernet switch for routing traffic to the local module or passing the data up or downstream as appropriate. Furthermore, in certain examples, the modular energy system6000includes secondary, low speed, communication interface between modules for critical, power related functions including module power sequencing and module power status. The secondary communications interface can, for example, be a multi-drop Local Interconnect Network (LIN), where the header module is the master and all downstream modules are slaves. In various aspects, as illustrated inFIG.15, a standby power domain6010is a separate output from the AC/DC power supply6003that is always live when the supply is connected to mains power6020. The standby power domain6010is used by all the modules in the system to power circuitry for a mitigated communications interface, and to control the local power to each module. Further, the standby power domain6010is configured to provide power to circuitry that is critical in a standby mode such as, for example, on/off command detection, status LEDs, secondary communication bus, etc. In various aspects, as illustrated inFIG.15, the individual surgical modules6004lack independent power supplies and, as such, rely on the header module6002to supply power in the stack configuration. Only the header module6002is directly connected to the mains power6020. The surgical modules6004lack direct connections to the mains power6020, and can receive power only in the stack configuration. This arrangement improves the safety of the individual surgical modules6004, and reduces the overall footprint of the modular energy system6000. This arrangement further reduces the number of cords required for proper operation of the modular energy system6000, which can reduce clutter and footprint in the operating room. Accordingly, a surgical instrument connected to surgical modules6004of a modular energy system6000, in the stack configuration, receives therapeutic energy for tissue treatment that is generated by the surgical module6004from power delivered to the surgical module6004from the AC/DC power supply6003of the header module6002. In at least one example, while a header module6002is assembled in a stack configuration with a first surgical module6004′, energy can flow from the AC/DC power supply6003to the first surgical module6004′. Further, while a header module6002is assembled in a stack configuration with a first surgical module6004′ (connected to the header module6002) and a second surgical module6004″ (connected to the first surgical module6004′), energy can flow from the AC/DC power supply6003to the second surgical module6004″ through the first surgical module6004′. The energy generated by the AC/DC power supply6003of the header module6002is transmitted through a segmented power backplane6008defined through the modular energy system6000. In the example ofFIG.15, the header module6002houses a power backplane segment6008′, the first surgical module6004′ houses a power backplane segment6008″, and the second surgical module6004″ houses a power backplane segment6008″. The power backplane segment6008′ is detachably coupled to the power backplane segment6008″ in the stack configuration. Further, the power backplane6008″ is detachably coupled to the power backplane segment6008′″ in the stack configuration. Accordingly, energy flows from the AC/DC power supply6003to the power backplane segment6008′, then to the power backplane segment6008″, and then to the power backplane segment6008′″. In the example ofFIG.15, the power backplane segment6008′ is detachably connected to the power backplane segment6008″ via pass-through hub connectors6005,6006in the stack configuration. Further, the power backplane segment6008″ is detachably connected to the power backplane segment6008′″ via pass-through hub connectors6025,6056in the stack configuration. In certain instances, removing a surgical module from the stack configuration severs its connection to the power supply6003. For example, separating the second surgical module6004″ from the first surgical module6004′ disconnects the power backplane segment6008′″ from the power backplane segment6008″. However, the connection between the power backplane segment6008″ and the power backplane segment6008′″ remains intact as long as the header module6002and the first surgical module6004′ remain in the stack configuration. Accordingly, energy can still flow to the first surgical module6004′ after disconnecting the second surgical module6004″ through the connection between the header module6002and the first surgical module6004′. Separating connected modules can be achieved, in certain instances, by simply pulling the surgical modules6004apart. In the example ofFIG.15, each of the modules6002,6004includes a mitigated module control6023. The mitigated module controls6023are coupled to corresponding local power regulation modules6024that are configured to regulate power based on input from the mitigated module controls6023. In certain aspects, the mitigated module controls6023allow the header module6002to independently control the local power regulation modules6024. The modular energy system6000further includes a mitigated communications interface6021that includes a segmented communication backplane6027extending between the mitigated module controls6023. The segmented communication backplane6027is similar in many respects to the segmented power backplane6008. Mitigated Communication between the mitigated module controls6023of the header module6002and the surgical modules6004can be achieved through the segmented communication backplane6027defined through the modular energy system6000. In the example ofFIG.15, the header module6002houses a communication backplane segment6027′, the first surgical module6004′ houses a communication backplane segment6027″, and the second surgical module6004″ houses a communication backplane segment6027′″. The communication backplane segment6027′ is detachably coupled to the communication backplane segment6027″ in the stack configuration via the pass-through hub connectors6005,6006. Further, the communication backplane6027″ is detachably coupled to the communication backplane segment6027″ in the stack configuration via the pass-through hub connectors6025,6026. Although the example ofFIG.15depicts a modular energy system6000includes a header module6002and two surgical modules6004′6004″, this is not limiting. Modular energy systems with more or less surgical modules are contemplated by the present disclosure. In some aspects, the modular energy system6000includes other modules such as, for example, a communications module. In some aspects, the header module6502supports a display screen such as, for example, the display2006(FIG.7A) that renders a GUI such as, for example, the GUI2008for relaying information regarding the modules connected to the header module6002. The GUI2008of the display screen2006can provide a consolidated point of control all of the modules making up the particular configuration of a modular energy system. FIG.16depicts a simplified schematic diagram of the modular energy system6000, which illustrates a primary communications interface6040between the header module6002and the surgical modules6004. The primary communications interface6040communicably connects module processors6041,6041′,6041″ of the header module6002and the surgical modules6004. Commands generated by the module processor6041of the header module are transmitted downstream to a desired functional surgical module via the primary communications interface6040. In certain instances, the primary communications interface6040is configured to establish a two-way communication pathway between neighboring modules. In other instances, the primary communications interface6040is configured to establish a one-way communication pathway between neighboring modules. Furthermore, the primary communications interface6040includes a segmented communication backplane6031, which is similar in many respects to the segmented power backplane6008. Communication between the header module6002and the surgical modules6004can be achieved through the segmented communication backplane6031defined through the modular energy system6000. In the example ofFIG.16, the header module6002houses a communication backplane segment6031′, the first surgical module6004′ houses a communication backplane segment6031″, and the second surgical module6004″ houses a communication backplane segment6031′″. The communication backplane segment6031′ is detachably coupled to the communication backplane segment6031″ in the stack configuration via the pass-through hub connectors6005,6006. Further, the communication backplane6031″ is detachably coupled to the communication backplane segment6031″ in the stack configuration via the pass-through hub connectors6025,6026. In at least one example, as illustrated inFIG.16, the primary communications interface6040is implemented using the DDS framework running on a Gigabit Ethernet interface. The module processors6041,6041′,6041″ are connected to Gigabit Ethernet Phy6044, and Gigabit Ethernet Switches6042′,6042″. In the example ofFIG.16, the segmented communication backplane6031connects the Gigabit Ethernet Phy6044and the Gigabit Ethernet Switches6042of the neighboring modules. In various aspects, as illustrated inFIG.16, the header module6002includes a separate Gigabit Ethernet Phy6045for an external communications interface6043with the processor module6041of the header module6002. In at least one example, the processor module6041of the header module6002handles firewalls and information routing. Referring toFIG.15, the AC/DC power supply6003may provide an AC Status signal6011that indicates a loss of AC power supplied by the AC/DC power supply6003. The AC status signal6011can be provided to all the modules of the modular energy system6000via the segmented power backplane6008to allow each module as much time as possible for a graceful shutdown, before primary output power is lost. The AC status signal6011is received by the module specific circuits6013,6014,6015, for example. In various examples, the system power control6017can be configured to detect AC power loss. In at least one example, the AC power loss is detected via one or more suitable sensors. Referring toFIGS.15and16, to ensure that a local power failure in one of the modules of the modular energy system6000does not disable the entire power bus, the primary power input to all modules can be fused or a similar method of current limiting can be used (e-fuse, circuit breaker, etc.). Further, Ethernet switch power is segregated into a separate power domain6013so that the primary communications interface6040remains alive when local power to a module is removed. In other words, primary power can be removed and/or diverted from a surgical module without losing its ability to communicate with other surgical modules6004and/or the header module6002. Over-Molded Light Pipe With Mounting Features Having described a general implementation the header and modules of modular energy systems2000,3000,6000, the disclosure now turns to describe various aspects of other modular energy systems. The other modular energy systems are substantially similar to the modular energy system2000, the modular energy system3000, and/or the modular energy system6000. For the sake of brevity, various details of the other modular energy systems being described in the following sections, which are similar to the modular energy system2000, the modular energy system3000, and/or the modular energy system6000, are not repeated herein. Any aspect of the other modular energy systems described below can be brought into the modular energy system2000, the modular energy system3000, or the modular energy system6000. As referenced elsewhere herein, modules of a modular energy system can include a number of different ports configured to deliver different energy modalities to corresponding surgical instruments that are connected thereto. For example, the energy module2004can include a port assembly2012that includes a bipolar port2014, a first monopolar port2016a, a second monopolar port2016b, a neutral electrode port2018(to which a monopolar return pad is connectable), and a combination energy port2020. In one aspect, the ports2012,2014,2016a,2016b,2018,2020can be configured to relay information to users. For example, any of the ports2012,2014,2016a,2016b,2018,2020can include light assemblies2015that can be configured to relay information to the user regarding the port according to their color or state (e.g., flashing, solid, patterned, etc.). For example, a light assembly2015can change from a first color to a second color when a plug is fully seated within the respective port. As another example, a light assembly2015can flash a color, such as red, when a plug is improperly seated in the respective port. In one aspect, the color or state of the light assemblies2015can be controlled by the header module2002. For example, the header module2002can cause the light assembly2015of each port to display a color corresponding to the color display for the port on the GUI2008. Various other aspects are envisioned where the ports can shine any number of colors for the purposes of conveying information to a user, such as when a port is available for use, when a port is not available for use, when there is a problem with a port, an energy level associated with a port, etc. As the light generated by the energy module2004and the light assemblies2015can provide a user with critical information regarding the current state and functionality of the ports of the port assembly2012, it is important that light generated for a respective port is only visible where intended. For example, it is important that light emitted to convey information for one port, such as the bipolar port2014, is not inadvertently shone through the energy module2004and seen at other locations of the energy module, such as at the monopolar port2016athat is adjacent to the bipolar port2014. This inadvertent light could confuse a clinician as to what information the energy module is trying to convey. In various aspects, the light assemblies2015can comprise light pipes, which are materials that are meant to allow light to travel while being diffused, increase the apparent brightness of printed circuit board (PCB) mounted light emitting diodes (LEDs) within the module, while also providing a more attractive user interface to the user. In one aspect, should a gap be defined between the light pipe and any of its surrounding components, light could inadvertently shine to other areas where the light is not intended to shine, such as through the energy module and out of another port. Therefore, a need exists to ensure that light is only shone to areas where intended. In addition, it is desirable that the light pipe be able to be mounted to the enclosure of the energy module. Mounting the light pipe to the enclosure would provide an ease in assembly of the port with the enclosure, while allowing for quick replacement of the same should any component of the port need replaced. Referring toFIG.17, a port module400is provided, according to at least one aspect of the present disclose. In one aspect, the port module400can include a receptacle402, a light pipe404surrounding the receptacle402, and mounting features410extending from the light pipe404. While the port module shown inFIG.17is intended for use as one type of port module400(monopolar port module, bipolar port module, neutral electrode port module, combo energy port module, etc.), it should be understood that the port modules can be sized and configured for use as other types of port modules, such as port module401shown inFIG.18, that includes a different number of apertures to receive a different type of plug than port module400. In various aspects, the mounting features410can include a mounting arm412and an aperture414defined in the mounting arm412. As shown inFIGS.23and24, as an example, the aperture414can be sized to receive a fastener415, such as a screw, therethrough to mount the port module400to an enclosure406of an energy module408. In various aspects, as shown inFIG.24, the port module400can be mounted to an inner face407of the enclosure406. Various other aspects are envisioned where the port module400can be mounted to a different part of the enclosure406, such as to an outer face of the enclosure406. In various aspects, the mounting features410can further include alignment rails that can assist in properly aligning the apertures414of the mounting features410with corresponding mounting holes418defined in the enclosure406, illustrated inFIG.25, which are sized to receive a fastener415for mounting the port module400to the enclosure406. In one aspect, the alignment rails can be received by a track defined by the enclosure406to guide the aperture414into operable alignment with the mounting hole418of the enclosure406. The alignment rails and the tracks can ensure that the port module400is properly received and positioned in apertures420defined in the enclosure406, as is shown inFIG.25. In various aspects, the port module400can further include auxiliary alignments rails on other areas of the light pipe404that do not include mounting features410to further assist in aligning the port module400with the corresponding aperture420defined in the enclosure406. Similar to the alignment rails, the auxiliary alignment rails can be received by a track to further assist in ensuring that the port module400is properly received and positioned in the aperture420defined in the enclosure406. In one aspect, the alignment rails, the auxiliary alignment rails, and tracks can be defined to ensure the front face of the port module400fits flush with the external face of the enclosure406, thereby preventing the port module400from “sticking out” past the front face of the enclosure406. In various aspects, the mounting arms412can be received by a mounting boss within the enclosure406. The mounting arms412can be positioned on the light pipe404such that they do not nominally touch off the mounting boss of the enclosure406, which can cause a forward bias, ensuring the alignment rails make contact with the inside surface of the enclosure406. As shown inFIG.17, the port module400can include two mounting features410extending from the light pipe404to allow the port module400to be mounted to the enclosure406of the energy module408. The mounting features410can extend from opposite corners of the port module400to provide for a secure connection of the port module400to the enclosure406. The use of at least two mounting features410can ensure that the port module400does not rotate out of its intended position when mounted to the enclosure406. While two mounting features410are shown and described, any number of mounting features410can be utilized to couple the port module400to the enclosure406. While the mounting features410are shown extending from opposite corners of the light pipe404, the mounting features410can extend from any suitable location of the light pipe404to ensure that a secure connection is made between the port module400to the enclosure406to maintain the port module400in the respective apertures420. The mounting features410can also be sized and positioned such that apertures414of the mounting features410operably align with mounting holes418defined in the enclosure406to ensure that the fastener415can extend through both the aperture414and the mounting hole418to properly mount the port module400to the enclosure406. In one aspect, the apertures414can comprise threads such that the aperture414can be threadably coupled to the fastener415that also threadably couples to the mounting hole418of the enclosure406. In one aspect, light emitted from the light pipe404can be emitted laterally therefrom and enter the mounting features410, which can cause the occurrence of bright or dull spots in the port module400. In various aspects, the mounting features410can extend from the light pipe404such that a distance dfis defined between the front faces438of the mounting features410and the front face439of the light pipe404. The distance dfcan be selected in order to reduce the occurrence of bright or dull spots, due to light emitted light pipe404entering the areas of the mounting features410. In various aspects, the cross sectional area at the interface between the mounting arms412of the mounting features410and light pipe404body can be reduced to further minimize light loss. In one aspect, the above-described improvements can reduce the occurrence of inconsistent output from the light pipe404. In various aspects, the mounting features410can be comprised a light diffusing material, such as an opaque plastic. In various aspects, the enclosure406of the energy module408can define predefined compartments422, shown inFIGS.24and25, that can receive the port modules400therein. In one aspect, the mounting features410can be sized such that the port modules400can fit within predefined compartments422defined within the enclosure406that include the apertures420. In various aspects, the enclosure406can define a plurality of ribs421that can separate the predefined compartments422of the enclosure406. The ribs421can be sized and positioned to prevent compartment422to compartment422light bleeding, as will be discussed in more detail below, to ensure that light emitted within one compartment422for one port module400is not inadvertently seen in another compartment422that includes a second port module400. While ribs421are shown as being defined by the enclosure406to separate the predefined compartments422, any number of ribs421can be utilized within other areas of the enclosure406to further inhibit light travel within the enclosure406. In various aspects, the ribs421and the enclosure406can be of unitary construction. For example, the enclosure406and the ribs421can be formed together with an injection molding process. In various aspects, the ribs421can be separate components that can be removably or permanently attached to enclosure406. For example, the ribs421could be part of a separate component of the system that are put in place during assembly of the enclosure406. In various aspects, referring toFIGS.23-25, each compartment422of the enclosure406can define a chimney419, which can serve as a light guide to guide light emitted from the LEDs to icons that exist on the outer surface of the enclosure406. The chimneys419can cause the icons to illuminate to convey various states associated with for the port module400positioned in the compartment422. In one aspect, the chimneys419can include a very shallow diffuse material and direct the light towards the outer indicator for the purposes of conveying information to a user of the system. In one aspect, the chimneys can block light for a dedicated LED for the indicators In various aspects, the enclosure406can define vent holes423, as shown inFIGS.24,25,26, and27, that can function to vent out heat generated within the energy module408. During use of the energy module408, light could bleed through the vent holes423and shine into other areas of the operating room, thus confusing the clinician as to what signals are trying to be conveyed. In one aspect, the ribs421can be defined within the enclosure406to prevent light generated within the energy module408from bleeding out through the vent holes423. In various other aspects, the vents423could be angled, such as is shown inFIG.37and will be described in more detail elsewhere herein, to further inhibit light escape from the energy module408. In one aspect, referring again toFIG.17, the mounting features410can be molded directly onto the light pipe404. In various aspects, the light pipe404and the mounting features410can be of unitary construction. In various aspects, the light pipe404and the mounting features410can be manufactured by a molding process, such as with an injection molding process, as an example. Molding of the mounting features410directly on the light pipe404can ensure accurate placement of the port module400relative to the apertures420of the enclosure406as the port module400is mounted to the enclosure406, as well as ensures accurate placement of the light pipe404relative to LEDs within the energy module408, as will be described in more detail below. In various other aspects, the light pipe404and the mounting features410can be separately constructed and then coupled together, such as with a bonding agent. In various aspects, the mounting features410can be removably coupleable to the light pipe404to allow for replacement of the mounting features410should one break, as an example. In various aspects, referring now toFIG.22, the energy module408can include a control circuit430that can be positioned within the energy module408adjacent to the apertures420of the energy module408. The control circuit430can define a plurality of apertures432that can be sized and positioned along the control circuit430to align with the apertures420defined in the enclosure406such that the port modules400can extend through both sets of apertures420,432. In various aspects, the control circuit430can include a plurality of LEDs positioned thereon that face an inner wall407and the apertures420. The plurality of LEDs can be grouped and positioned adjacent to the apertures420defined in the enclosure406such that, when information is to be conveyed to a user, a specific grouping of LEDs of the plurality of LEDs can be illuminated and shine through the respective aperture420. Example LEDs on a control circuit can be seen onFIG.37. In various aspects, the port modules400can comprise a port module circuit434that can electrically couple to the control circuit430when the port module400is coupled to the energy module408. In one aspect, the control circuit430can transmit signals to the port module circuit434when the port module400is coupled to the enclosure406, as will be described in more detail below, for the purposes of transmitting electrical signals to electrosurgical instruments that are coupled to the port module400. In various aspects, referring toFIG.17, the port modules400can include a circuit holder435extending from the receptacle402, which can be sized to hold the port module circuit434. As referenced above, the port modules400can include a light pipe404. The light pipes404can be optically coupled to respective LEDs on the control circuit430such that that the light pipes404can transmit optical, informational signals to a user of the energy module408from the LEDs. In one aspect, when the LEDs associated with one port module400are illuminated, light emitting from the LED(s) can emit into and through the light pipe404, providing an increase the apparent brightness of the light emitted from the LED(s) and provide a user of the energy module408with a status of the port module400according to the light that is emitted by the LEDs. In various aspects, the LEDs and light pipe404can emit solid light, flashing light, patterned light, or any other type of light state, to indicate information to the user about a status of the port module400. Further, the LEDs and light pipe404can emit any number of colors according to the status of the port module400, such as operational status, energy level status, etc. As one example, the LEDs and light pipe404can emit solid green light when the port module400is ready for use, emit flashing red light when the port module400is not ready for use, and emit patterned yellow light when the port module400is being prepared for use. Any number of color and light states (solid, flashing, patterned, etc.) can be utilized to convey information to a user. As referenced above, referring again toFIG.17, the port module400can include a receptacle402. As shown inFIG.17, the perimeter of the receptacle402can be defined by the inner surface of the light pipe404. In various aspects, the receptacle402can be sized to receive a plug from a corresponding surgical instrument therein, such as is shown inFIG.4, as an example. The receptacle402can include a back wall424that defines apertures426therein and sidewalls428extending away from the back wall424. The size of the receptacle402, as well as the size, position, and number of apertures426defined in the back wall424, can be defined to correspond to an intended plug of a surgical instrument to be used with the port module400. For example, in one aspect, referring toFIG.17, the back wall424can define three apertures corresponding to one type of plug. In another example aspect, referring toFIG.18, the back wall424of a port module401can define four apertures corresponding to a second type of plug. In various aspects, referring now toFIG.26, the port module circuit434can be electrically coupled to pin receptacles436that are disposed within the apertures426of the back wall424. The pin receptacles436can be in electrical communication with the port module circuit434and can be sized to receive pins from plugs of electrosurgical instruments therein. When the pins of the plugs are positioned in the pin receptacles436and the port module circuit434is in electrical communication with the control circuit430of the energy module408, the control circuit430of the energy module408can transmit electrical signals to the electrosurgical instrument. In various aspects, the receptacle402can be molded directly within light pipe404to define a seal therebetween. In various aspects, the light pipe404can be comprised of a first material and the receptacle402can be comprised of a second material, where the first material has a higher melting temperature than the first material. The light pipe404can be injection molded with the first material to define the shape of the light pipe404. Once the light pipe404has been formed, the receptacle402can be injection molded with the second material within the formed light pipe404to define the back wall424and sidewalls428. Once the second material has been injected into the light pipe404, the apertures426can be defined in the back wall424according to the intended use of the port module400. Injection molding the receptacle402within the light pipe404allows for the creation of a seal therebetween, which can prevent any inadvertent light from escaping between the light pipe404and the receptacle402. This molding process can also ensure a strong bond between the light pipe404and the receptacle402. The strong bond between the light pipe404and the receptacle402is critical as the mounting features410on the light pipe404are needed for mounting the port module400to the enclosure406, and therefore, the strong bond is critical to ensure accurate alignment of the port module400with the apertures420of the enclosure406. As referenced above, a seal can be formed between the receptacle402and the light pipe404. The seal can ensure that light from the light pipe404don't shine between the light pipe404and the receptacle402, as well as ensures that the port module400is properly mounted to the enclosure406. In various aspects, the receptacle402can be comprised of an opaque material. In one aspect, the opaque material can comprise a plastic opaque material. As referenced above, as a seal is defined between the light pipe404and the opaque receptacle402, the opaque material can prevent light that is emitted from the LEDs and the light pipe404from inadvertently escaping and shining into unintended areas of the energy module408. As one example, the seal and opaque material can ensure that light emitted from one grouping of LEDs and a light pipe404of one port module400is not mistakenly seen at another location of the energy module408, such as at another port module400. In various aspects, referring now toFIGS.20and21, the port module400can further include engagement features that improve mechanical strength and engagement between the light pipe404and other components of the port module400, such as the receptacle402. In one aspect, engagement features can comprise engagement arms440defined in the light pipe404that extend toward and be received in notches442defined in the receptacle402. The engagement arms440can engage notches442, which can improve the engagement between the light pipe404and the receptacle402. In various aspects, the engagement arms440and notches442can be defined at any suitable location on the port module400to improve the mechanical strength and engagement between the light pipe404and other components of the port module400, such as the receptacle402. In various aspects, referring toFIG.17, the light pipe404can define stops416that can define recesses to receive engagement members417(seeFIG.21) extending from the receptacle402(note:FIG.21illustrates a phantom view of the light pipe404such that the outer surface of the receptacle402and an engagement member417extending therefrom can be seen while the receptacle402is positioned in the light pipe404). In one aspect, the stops416and engagement members417of the receptacle402can be utilized to align the light pipe404with the receptacle402. In one aspect, the engagement members417can be received in the stops416to create a flush relationship between the light pipe404and the receptacle402through a positive stop. Light Blocking PCB Inserts As referenced elsewhere herein, modules of a modular energy system can utilize light for the purposes of conveying information to a user of the modular energy system. For example, ports2012,2014,2016a,2016b,2018,2020can be configured to relay information to users. For example, any of the ports2012,2014,2016a,2016b,2018,2020can include light assemblies2015that can be configured to relay information to the user regarding the port according to their color or state (e.g., flashing, solid, patterned, etc.). For example, a light assembly2015can change from a first color to a second color when a plug is fully seated within the respective port. As another example, a light assembly2015can flash a color, such as red, when a plug is improperly seated in the respective port. In one aspect, the color or state of the light assemblies2015can be controlled by the header module2002. For example, the header module2002can cause the light assembly2015of each port to display a color corresponding to the color display for the port on the GUI2008. Various other aspects are envisioned where the ports can shine any number of colors for the purposes of conveying information to a user, such as when a port is available for use, when a port is not available for use, when there is a problem with a port, an energy level of a port, etc. As the light generated by the modules provides a user with critical information regarding the current state of the module, it is important that light generated by the module is only visible where intended. As described elsewhere herein, the modules can include an enclosure, such as enclosure406, that houses the components of the module therein. In various aspect, the enclosure can include apertures, such as apertures420, defined therein that are sized to receive port modules, such as port modules400, therein. The enclosure can further include a control circuit, such as control circuit430, that can control various functions of the module, such as controlling LEDs thereon that are emitted to convey information to the user regarding the status of the port modules400, as well as controlling an amount or type of energy that is delivered to an electrosurgical instrument that is coupled to the port module. The control circuit can also include apertures, such as apertures432, that can be sized and positioned adjacent to apertures of the enclosure such that the port modules can extend through both the apertures of the enclosure and the apertures of the control circuit when the port module is coupled to the energy module. In various aspects, as referenced above, the control circuit can further include LEDs that are mounted to the control circuit. The LEDs can be positioned on the control circuit such that light emitted from the LEDs can emit toward the aperture of the enclosure, thus conveying information to the user about the status of the port modules. Referring now toFIG.31, when port modules450, which can be similar to port modules400, extend through apertures defined in the enclosure451and apertures452defined in the control circuit454, a gap456can be defined between the inner perimeter of the aperture452and the port module450. As a result of the gap456, light emitted from the LEDs on the control circuit454can escape through the gap456and emit into other areas of the enclosure451. In some scenarios, the escaped light could enter another aperture452defined in the control circuit, causing the light corresponding to one port module450to inadvertently been seen at different port module450location. As a result, a user could be confused as to which port module450is being illuminated and what information is being conveyed by the module. In other instances, the escaped light could also escape the enclosure451through the vents458defined in the sides of the enclosure451and be seen at other locations of the operating room. Accordingly, a need exists to block reward light travel through the gap456to prevent inadvertent light visibility at other locations of the enclosure451and the operating room. Referring now toFIG.28, a light blocking insert460is provided, according to at least one aspect of the present disclosure. The light blocking insert460can include a face462, guidewalls464extending from the face462, and mounting features466extending from the face462. Referring toFIGS.29and30, the face462of the light blocking insert460can be defined such that, when the light blocking insert460is inserted into the aperture452of the control circuit454, as will be discussed in more detail below, the face462can seal the gap456to prevent light from escaping through the gap456to other areas of the enclosure451. As referenced above, the light blocking insert460can include a plurality of mounting features466. The mounting features466can be movable relative to the guidewalls464between a resting position (seen inFIG.28) and a depressed position. In various aspects, the mounting features466can be biased toward the resting position. While six mounting features are shown inFIG.28, any more of less mounting features466can be utilized. In various aspects, the mounting features466can include a base468extending from the face462, a lip470extending from the base468, and an actuator portion472extending from the base468. In various aspects, the lip470can extend transversely relative to the base468and the actuator portion472. In various aspects, the light blocking insert460can be removably coupled to the control circuit454to cover the gap456. In operation, the guidewalls464and the mounting features466can be inserted through the aperture452of the control circuit454and toward the aperture of the enclosure451. As the light blocking insert460moves through the aperture452of the control circuit454, the lips470of the mounting features466can engage the inner perimeter of the aperture452. The aperture452can force the mounting features466to rotate toward the depressed positions, allowing the lips470to pass from a first side of the control circuit454, through the aperture452, and to a second side of the control circuit454. Once the lips470move beyond the aperture452, the mounting features466can be snap back to the resting position, where the bases468and the lips470of the mounting features466can engage the control circuit454, maintaining the position of the light blocking insert460relative to the control circuit454, such as is shown inFIGS.29and30. In one aspect, while the mounting features466are moving toward and through the apertures452, the guidewalls464can assist in guiding the mounting features466into operable alignment with the inner perimeter of the apertures452. With the mounting features466operably engaged with the control circuit454, a user can remove the light blocking insert460from the control circuit454. In one aspect, the light blocking insert460can be removed by pushing the mounting features466toward the depressed position, thereby releasing the lip470and the base468from the control circuit454. As referenced above, the mounting features466can include an actuator portion472extending from the base468. In operation, a user can move the mounting features466toward the depressed position by pressing on the actuator portions472with, for example, their finger, to release the lip470and the base468from the control circuit454, thereby allowing the light blocking insert460to be removed from the aperture452. In various aspects, the actuator portion472can include grips defined therein to assist a user with moving the mounting features466toward the depressed position. In various aspects, the light blocking insert460can be comprised of a plastic material and can be manufactured with a molding process. In one aspect, the molding process can be an injection molding process. In various aspects, the light blocking insert460can be manufactured using any other suitable manufacturing process, such as an additive manufacturing process, a 3D printing process, etc. In various aspects, the light blocking insert460can be comprised of an opaque plastic material. In various aspects, the light blocking insert460can be comprised of an opaque elastomeric material. Angled Vents For Light Blocking As referenced elsewhere herein, modules of a modular energy system can utilize light for the purposes of conveying information to a user of the modular energy system. For example, ports2012,2014,2016a,2016b,2018,2020can be configured to relay information to users. For example, any of the ports2012,2014,2016a,2016b,2018,2020can include light assemblies2015that can be configured to relay information to the user regarding the port according to their color or state (e.g., flashing, solid, patterned, etc.). For example, a light assembly2015can change from a first color to a second color when a plug is fully seated within the respective port. As another example, a light assembly2015can flash a color, such as red, when a plug is improperly seated in the respective port. In one aspect, the color or state of the light assemblies2015can be controlled by the header module2002. For example, the header module2002can cause the light assembly2015of each port to display a color corresponding to the color display for the port on the GUI2008. Various other aspects are envisioned where the ports can shine any number of colors for the purposes of conveying information to a user, such as when a port is available for use, when a port is not available for use, when there is a problem with a port, an energy level of a port, etc. As the light generated by the modules provides a user with critical information regarding the current state of the module, it is important that light generated within the module only be visible where intended. In various aspects, modules can include an enclosure, such as enclosure406, that houses the components of the module therein. In some aspects, the enclosure can include vents, such as vents423,458, defined therein for the purposes of venting heat out of the module to prevent the module from overheating. These vents, however, can allow for unintended escape of light generated within the module. This escaped light may shine onto other areas within the operating room that also rely on light for the purposes of indication. This overlap of light patterns may cause the clinician to become confused as what information is intended to be conveyed. Therefore, it is desirable to ensure that light generated by a module is not visible outside of the enclosure, such as through the vents, except for where intended. Referring now toFIG.32, a module500is provided according to at least one aspect of the present disclosure. The module can be any suitable module for use with a modular energy system, such as a header module2002, an energy module2004, a technology module2040, a visualization module2042, or any suitable module for use with a modular energy system. In one aspect, the module can be an energy module that includes a port assembly502, which can be similar to port assembly2012. In one aspect, the module500can include an enclosure504that houses components of the module therein. The enclosure504can include a plurality of faces, such as a front face506, a back face508, a pair of sidewalls510, a top face512, and a bottom face514. As shown inFIG.32, the enclosure504of the module500can define vents516, or holes, in the sidewalls510that can vent heat generated by the module500to prevent the module500from overheating. While vents516are shown and described are being defined in the sidewalls510of the enclosure504, it should be understood that vents516can be defined in any suitable location on the enclosure504, such as any other of the faces506,508,512,514of the enclosure504for the purposes of venting heat generated by the module500. In various aspects, the enclosure504can be defined with an injection molding process and the vents516can be drafted. In one aspect, as shown most clearly inFIG.37, the enclosure504can define vents516that can be angled relative to a sidewall plane defined by the sidewall510of the enclosure504, which can hinder light escape from the enclosure504. In various aspects, the vents516can include a vent inlet518, a vent outlet520, and a track522extending from the vent inlet518to the vent outlet520. In one aspect, the tracks522can be angled θ relative to the sidewall plane at any suitable angle to inhibit light from escaping the enclosure504. In one aspect, as is shown inFIG.37, the vent inlets518and vent outlets520can be vertically offset such that the track522defines a non-perpendicularly angle θ relative to the sidewall plane. In one aspect, the vent inlets518and vent outlets520can be vertically offset such that the angle θ of the track522is 45° relative to the sidewall plane. In other aspects, the vent inlets518and vent outlets520can be offset such that the angle θ of the tracks522are greater than 45° relative to the sidewall plane, such as 50°, 55°, 60°, 70°, or any other suitable angle. In other aspects, the vent inlets518and vent outlets520can be offset such that the angle θ of the track522is less than 45° relative to the sidewall plane, such as 40°, 35°, 30°, 20°, or any other suitable angle. In various aspects, some vents516can include an angle θ that differs from other vents. Stated another way, the enclosure504can include non-uniformly angled vents516angled relative to the sidewall plane. In one aspect, as is shown inFIG.37, the enclosure504can define vents516that can be angled “downward”, where the vent outlets520can be positioned vertically below the vent inlets518, closer to the bottom face514of the enclosure. In various other aspects, the enclosure504can define vents516that can be angled “upward”, where the vent outlets520can be positioned vertically above the vent inlets518, closer to the top face512of the enclosure. In various other aspects, the enclosure504can include a combination of upward angled vents516and downward angled vents516. In various aspects, the enclosure504can define vents516that are angled in other directions, such as forward angled or backward angled. For example, in various aspects, the enclosure504can define vents516that can be angled “forward”, where the vent outlets520can be positioned closer to the front face506than the vent inlets518. In various aspects, the enclosure504can define vents516that can be angled “backward”, where the vent outlets520can be positioned closer to the back face508than the vent inlets518. In various aspects, the enclosure504can define vents516that can be angled in more than one direction. For example, in one example aspect, the enclosure504can define vents516where the vent outlets520can be positioned closer to the front face506and the top face512when compared to the vent inlets518. The use of angled vents can provide a similar, or improved, airflow compared to non-angled vents, as well as can provide the added benefit of preventing light from escaping the module. In various aspects, the enclosure504can define vents516that can be angled in a plurality of non-uniform directions. As referenced above, the vents516can include a vent inlet518, a vent outlet520, and a track522extending from the vent inlet518to the vent outlet520. In various aspects, the tracks522can be linear, as shown inFIG.37. In various aspects, the tracks522can be non-linear (i.e., the tracks522non-linearly extend from the vent inlet518to the vent outlet520). In various aspects, the track522can include a first track portion extending from the vent inlet518and a second track portion angled relative to the first track portion, extending from the first track portion and to the vent outlet520. The use of multiple, angled track portions between the vent inlet518and vent outlet520can further prevent light from escaping the enclosure504. Low Pressure Mold (LPM) on a PCB for LED Light Blocking As referenced elsewhere herein, modules of a modular energy system can utilize light for the purposes of conveying information to a user of the modular energy system. For example, ports2012,2014,2016a,2016b,2018,2020can be configured to relay information to users. For example, any of the ports2012,2014,2016a,2016b,2018,2020can include light assemblies2015that can be configured to relay information to the user regarding the port according to their color or state (e.g., flashing, solid, patterned, etc.). For example, a light assembly2015can change from a first color to a second color when a plug is fully seated within the respective port. As another example, a light assembly2015can flash a color, such as red, when a plug is improperly seated in the respective port. In one aspect, the color or state of the light assemblies2015can be controlled by the header module2002. For example, the header module2002can cause the light assembly2015of each port to display a color corresponding to the color display for the port on the GUI2008. Various other aspects are envisioned where the ports can shine any number of colors for the purposes of conveying information to a user, such as when a port is available for use, when a port is not available for use, when there is a problem with a port, an energy level of a port, etc. As the light generated by the modules provides a user with critical information regarding the current state of the module, it is important that light generated within the module only be visible where intended. As referenced elsewhere herein, the modules can include an enclosure and a control circuit positioned therein. In one aspect, the control circuit can include a plurality of LEDs positioned thereon that face an inner wall of the enclosure and apertures defined in the enclosure. The plurality of LEDs can be grouped and positioned adjacent to the apertures defined in the enclosure such that, when information is to be conveyed to a user, a specific grouping of LEDs of the plurality of LEDs can be illuminated and shine through the respective aperture. This light can convey information associated with a port module that is positioned within the respective aperture, signifying a state of the port module (ready for use, not ready for use, an energy level associated with the port module, etc.). As the plurality of LEDs can be grouped and positioned adjacent to a plurality of apertures defined in the enclosure, there is a chance that light generated by a first grouping of LEDs may be seen through not only the respective aperture associated with the first grouping of LEDs, but also another aperture that may be in close proximity to the first grouping of LEDs. For example, when light is emitted from LEDs, a user has no control over what direction the light emitted from the LEDs goes, which can result in light being seen at other locations within the module other than where intended, such as through other apertures defined in the enclosure. This inadvertent light shone through the unintended apertures may confuse the clinician as to what information the LEDs are intending to convey to the clinician. A need exists to ensure that this inadvertent light shining is eliminated. Referring now toFIG.38, a control circuit550is provided, according to at least one aspect of the present disclosure. In various aspects, the control circuit550can include an aperture552defined therein that is sized to receive a port module, such as port modules400,401,450therein. In one aspect, the aperture552can be similar to apertures432,452. In various aspects, the control circuit550can further include a plurality of LEDs556surrounding the aperture552. The LEDs556can be mounted to the control circuit550and can be in electrical communication therewith such that the control circuit550can control light that can be emitted by the LEDs. In one aspect, the control circuit550can control the LEDs556to cause the LEDs556to emit light according to a current status of a port module that is positioned within the aperture552. In various aspects, the control circuit550can further include a containment structure560including a plurality of sidewalls562extending from the control circuit550. The containment structure560can be positioned on the control circuit550such that the sidewalls562encompass and surround the aperture552and the plurality of LEDs556. In various aspects, the sidewalls562can extend a height from a surface of the control circuit550such that the height of the sidewalls562is greater than or equal to the height of the LEDs. As shown inFIG.38, the containment structure560can define a rectangular-like shape to surround the LEDs556and the aperture552. In various other aspects, the containment structure560can define any suitable shape such that the containment structure560surrounds the LEDs556and the aperture552, such as a circular shape, a square shape, etc. In one aspect, the containment structure560can be low pressure molded (LPM) directed onto the surface of the control circuit550. Various other aspects are envisioned where the containment structure560is made separate from the control circuit550and removably coupled thereto with a bonding agent. In one aspect, the containment structure560can be comprised of an opaque material. In various aspects, the containment structure560can be comprised of an opaque plastic material. In various aspects, the containment structure560can be comprised of an opaque elastomer material. In one aspect, the use of the containment structure560can prevent light emitted from the LEDs556from traveling laterally along the control circuit550; rather, the containment structure560can direct light emitted from the LEDs556toward the apertures defined in the enclosure of the module. In various aspects, the containment structure560can direct light emitted from the LEDs556toward light pipes of the port modules positioned in the aperture552of the control circuit550. In one aspect, the sidewalls562can be of uniform thickness. In various other aspects, the sidewalls562can have varying thicknesses. For example, in one aspect, sidewalls562that are positioned between other groupings of LEDs on the control circuit550can be thicker than sidewalls562that are not separating groups of LEDs on the control circuit. In various aspects, the sidewalls can be of non-uniform heights. In various aspects, the sidewalls can be of uniform heights. In one aspect, the sidewalls562of the containment structure560can be positioned close to the LEDs556, as shown inFIG.38, such that light emitted by the LEDs556can be stopped and redirected toward the apertures of the enclosure as soon as possible from the light being emitted by the LEDs556. It should be understood that various aspects of the disclosure described herein, such as the disclosure associated withFIGS.17-38, as an example, may be utilized independently, or in combination, with one another. EXAMPLES Various aspects of the subject matter described herein are set out in the following numbered examples. Example 1. A port module removably coupleable to an energy module of a module energy system, wherein the port module comprises a light pipe and a receptacle defined by the light pipe, wherein the receptacle is configured to receive a plug of an electrosurgical instrument therein, and wherein a seal is defined between the light pipe and the receptacle. Example 2. The port module of Example 1, further comprising a mounting feature extending from the light pipe, wherein the energy module comprises an enclosure, and wherein the mounting feature is configured to mount to the enclosure. Example 3. The port module of Example 2, wherein the mounting feature comprises a mounting arm and an aperture defined in the mounting arm. Example 4. The port module of any or more of Examples 2 through 3, where a distance is defined between a front face of the light pipe and a front face of the mounting feature, and where the distance is selected to reduce occurrence of bright or dull spots of light emitted from the light pipe. Example 5. The port module of any one or more of Examples 1 through 4, wherein the light pipe comprises engagement arm, wherein the receptacle defines a notch, and where the engagement arm is received within the notch. Example 6. The port module of any one or more of Examples 1 through 5, wherein the receptacle comprises a back wall defining apertures, wherein the plug of the electrosurgical instrument comprises pins, and wherein the apertures are configured to receive the pins of the plug. Example 7. The port module of any one or more of Examples 5 through 6, wherein the receptacle further comprises sidewalls extending from the back wall, and wherein the back wall and the sidewalls are comprised of an opaque material. Example 8. An energy module of a module energy system, wherein the energy module comprises an enclosure defining a first aperture, a control circuit positioned within the enclosure, a port module, and a light blocking insert. The control circuit defines a second aperture aligned with the first aperture. The port module extends through the first aperture and the second aperture. A gap is defined between the second aperture and the port module. The light blocking insert is positioned in the gap. Example 9. The energy module of Example 8, wherein the light blocking insert is configured to removably couple to the control circuit. Example 10. The energy module of Example 9, wherein the light blocking insert comprises a plurality of mounting features, and wherein the plurality of mounting features are configured to removably couple the light blocking insert to the control circuit. Example 11. The energy module of Example 10, wherein the mounting features comprise a lip configured to engage the control circuit to removably couple the light blocking insert to the control circuit. Example 12. The energy module of any one or more of Examples 8 through 11, wherein the control circuit comprises an LED, and wherein the light blocking insert is configured to prevent light emitted from the LED from escaping through the gap. Example 13. The energy module of Example 12, wherein the control circuit further comprises sidewalls surrounding the LED, wherein the sidewalls are configured to direct light emitted from the LED toward the first aperture. Example 14. The energy module of Example 13, wherein the sidewalls are configured to prevent light emitted from the LED from escaping through the sidewalls. Example 15. The energy module of any one or more of Examples 13 through 14, wherein the sidewalls are comprised of an opaque material. Example 16. The energy module of any one or more of Examples 8 through 15, further comprising a vent, comprising a vent inlet, a vent outlet, and a track angularly extending from the vent inlet to the vent outlet. Example 17. An energy module of a module energy system, wherein the energy module comprises an enclosure defining a first aperture, a control circuit positioned within the enclosure, a port module, and a light blocking insert. The control circuit defines a second aperture aligned with the first aperture. The port module extends through the first aperture and the second aperture. The port module comprises a light pipe and a receptacle, wherein the receptacle is configured to receive a plug of an electrosurgical instrument therein, wherein a seal is defined between the light pipe and the receptacle, and wherein a gap is defined between the second aperture and the port module. The light blocking insert is positioned in the gap. Example 18. The energy module of Example 17, wherein the receptacle is comprised of an opaque material. Example 19. The energy module of any one or more of Examples 17 through 18, wherein the port module is configured to removably couple to the enclosure. Example 20. The energy module of any one or more of Examples 17 through 19, wherein the light blocking insert is configured to removably couple to the control circuit. While several forms have been illustrated and described, it is not the intention of Applicant to restrict or limit the scope of the appended claims to such detail. Numerous modifications, variations, changes, substitutions, combinations, and equivalents to those forms may be implemented and will occur to those skilled in the art without departing from the scope of the present disclosure. Moreover, the structure of each element associated with the described forms can be alternatively described as a means for providing the function performed by the element. Also, where materials are disclosed for certain components, other materials may be used. It is therefore to be understood that the foregoing description and the appended claims are intended to cover all such modifications, combinations, and variations as falling within the scope of the disclosed forms. The appended claims are intended to cover all such modifications, variations, changes, substitutions, modifications, and equivalents. The foregoing detailed description has set forth various forms of the devices and/or processes via the use of block diagrams, flowcharts, and/or examples. Insofar as such block diagrams, flowcharts, and/or examples contain one or more functions and/or operations, it will be understood by those within the art that each function and/or operation within such block diagrams, flowcharts, and/or examples can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. Those skilled in the art will recognize that some aspects of the forms disclosed herein, in whole or in part, can be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the subject matter described herein are capable of being distributed as one or more program products in a variety of forms, and that an illustrative form of the subject matter described herein applies regardless of the particular type of signal bearing medium used to actually carry out the distribution. Instructions used to program logic to perform various disclosed aspects can be stored within a memory in the system, such as dynamic random access memory (DRAM), cache, flash memory, or other storage. Furthermore, the instructions can be distributed via a network or by way of other computer readable media. Thus a machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer), but is not limited to, floppy diskettes, optical disks, compact disc, read-only memory (CD-ROMs), and magneto-optical disks, read-only memory (ROMs), random access memory (RAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic or optical cards, flash memory, or a tangible, machine-readable storage used in the transmission of information over the Internet via electrical, optical, acoustical or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.). Accordingly, the non-transitory computer-readable medium includes any type of tangible machine-readable medium suitable for storing or transmitting electronic instructions or information in a form readable by a machine (e.g., a computer). As used in any aspect herein, the term “control circuit” may refer to, for example, hardwired circuitry, programmable circuitry (e.g., a computer processor including one or more individual instruction processing cores, processing unit, processor, microcontroller, microcontroller unit, controller, digital signal processor (DSP), programmable logic device (PLD), programmable logic array (PLA), or field programmable gate array (FPGA)), state machine circuitry, firmware that stores instructions executed by programmable circuitry, and any combination thereof. The control circuit may, collectively or individually, be embodied as circuitry that forms part of a larger system, for example, an integrated circuit (IC), an application-specific integrated circuit (ASIC), a system on-chip (SoC), desktop computers, laptop computers, tablet computers, servers, smart phones, etc. Accordingly, as used herein “control circuit” includes, but is not limited to, electrical circuitry having at least one discrete electrical circuit, electrical circuitry having at least one integrated circuit, electrical circuitry having at least one application specific integrated circuit, electrical circuitry forming a general purpose computing device configured by a computer program (e.g., a general purpose computer configured by a computer program which at least partially carries out processes and/or devices described herein, or a microprocessor configured by a computer program which at least partially carries out processes and/or devices described herein), electrical circuitry forming a memory device (e.g., forms of random access memory), and/or electrical circuitry forming a communications device (e.g., a modem, communications switch, or optical-electrical equipment). Those having skill in the art will recognize that the subject matter described herein may be implemented in an analog or digital fashion or some combination thereof. As used in any aspect herein, the term “logic” may refer to an app, software, firmware and/or circuitry configured to perform any of the aforementioned operations. Software may be embodied as a software package, code, instructions, instruction sets and/or data recorded on non-transitory computer readable storage medium. Firmware may be embodied as code, instructions or instruction sets and/or data that are hard-coded (e.g., nonvolatile) in memory devices. As used in any aspect herein, the terms “component,” “system,” “module” and the like can refer to a computer-related entity, either hardware, a combination of hardware and software, software, or software in execution. As used in any aspect herein, an “algorithm” refers to a self-consistent sequence of steps leading to a desired result, where a “step” refers to a manipulation of physical quantities and/or logic states which may, though need not necessarily, take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It is common usage to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. These and similar terms may be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities and/or states. A network may include a packet switched network. The communication devices may be capable of communicating with each other using a selected packet switched network communications protocol. One example communications protocol may include an Ethernet communications protocol which may be capable permitting communication using a Transmission Control Protocol/Internet Protocol (TCP/IP). The Ethernet protocol may comply or be compatible with the Ethernet standard published by the Institute of Electrical and Electronics Engineers (IEEE) titled “IEEE 802.3 Standard”, published in December, 2008 and/or later versions of this standard. Alternatively or additionally, the communication devices may be capable of communicating with each other using an X.25 communications protocol. The X.25 communications protocol may comply or be compatible with a standard promulgated by the International Telecommunication Union-Telecommunication Standardization Sector (ITU-T). Alternatively or additionally, the communication devices may be capable of communicating with each other using a frame relay communications protocol. The frame relay communications protocol may comply or be compatible with a standard promulgated by Consultative Committee for International Telegraph and Telephone (CCITT) and/or the American National Standards Institute (ANSI). Alternatively or additionally, the transceivers may be capable of communicating with each other using an Asynchronous Transfer Mode (ATM) communications protocol. The ATM communications protocol may comply or be compatible with an ATM standard published by the ATM Forum titled “ATM-MPLS Network Interworking 2.0” published August 2001, and/or later versions of this standard. Of course, different and/or after-developed connection-oriented network communication protocols are equally contemplated herein. Unless specifically stated otherwise as apparent from the foregoing disclosure, it is appreciated that, throughout the foregoing disclosure, discussions using terms such as “processing,” “computing,” “calculating,” “determining,” “displaying,” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices. One or more components may be referred to herein as “configured to,” “configurable to,” “operable/operative to,” “adapted/adaptable,” “able to,” “conformable/conformed to,” etc. Those skilled in the art will recognize that “configured to” can generally encompass active-state components and/or inactive-state components and/or standby-state components, unless context requires otherwise. The terms “proximal” and “distal” are used herein with reference to a clinician manipulating the handle portion of the surgical instrument. The term “proximal” refers to the portion closest to the clinician and the term “distal” refers to the portion located away from the clinician. It will be further appreciated that, for convenience and clarity, spatial terms such as “vertical”, “horizontal”, “up”, and “down” may be used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and/or absolute. Those skilled in the art will recognize that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to claims containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that typically a disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms unless context dictates otherwise. For example, the phrase “A or B” will be typically understood to include the possibilities of “A” or “B” or “A and B.” With respect to the appended claims, those skilled in the art will appreciate that recited operations therein may generally be performed in any order. Also, although various operational flow diagrams are presented in a sequence(s), it should be understood that the various operations may be performed in other orders than those which are illustrated, or may be performed concurrently. Examples of such alternate orderings may include overlapping, interleaved, interrupted, reordered, incremental, preparatory, supplemental, simultaneous, reverse, or other variant orderings, unless context dictates otherwise. Furthermore, terms like “responsive to,” “related to,” or other past-tense adjectives are generally not intended to exclude such variants, unless context dictates otherwise. It is worthy to note that any reference to “one aspect,” “an aspect,” “an exemplification,” “one exemplification,” and the like means that a particular feature, structure, or characteristic described in connection with the aspect is included in at least one aspect. Thus, appearances of the phrases “in one aspect,” “in an aspect,” “in an exemplification,” and “in one exemplification” in various places throughout the specification are not necessarily all referring to the same aspect. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more aspects. Any patent application, patent, non-patent publication, or other disclosure material referred to in this specification and/or listed in any Application Data Sheet is incorporated by reference herein, to the extent that the incorporated materials is not inconsistent herewith. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material. In summary, numerous benefits have been described which result from employing the concepts described herein. The foregoing description of the one or more forms has been presented for purposes of illustration and description. It is not intended to be exhaustive or limiting to the precise form disclosed. Modifications or variations are possible in light of the above teachings. The one or more forms were chosen and described in order to illustrate principles and practical application to thereby enable one of ordinary skill in the art to utilize the various forms and with various modifications as are suited to the particular use contemplated. It is intended that the claims submitted herewith define the overall scope.

11857253

DETAILED DESCRIPTION OF THE DISCLOSURE In one aspect, the present disclosure provides a system for assessment of biological tissue by measuring/monitoring characteristics of electromagnetic radiation on biological tissue. The includes a device having at least one antenna configured to transmit and receive assessment signals having frequencies of at least 1 MHz to and from tissue; and a high frequency output configured to output the received assessment signal to a network analyzer and signal processing device. In one embodiment the system is an ablation lesion assessment system. In embodiments, the system includes an RF ablation catheter with an antenna electrode, and optionally a vector network analyzer connected to the antenna electrode to enable reflection transmission measurements in a frequency range, i.e., S parameter measurements (S11 and S21/S12), data acquisition and an analysis interface which predicts extent of tissue-electrode contact and lesion progression in real-time is described. In addition to measuring endocardial potential and delivering ablation RF (300-900 KHz range), the electrode of the RF ablation catheter is designed to have an additional functionality of an RF/microwave antenna. This enables the electrode to transmit and receive electromagnetic energy/frequencies in DC to GHz frequency range to the tissue being ablated, thus transmitting ablation energy at 100-700 KHz, sensing endocardial potential, as well as measuring S parameters in the KHz-GHz frequency range. The present disclosure provides various embodiments of the antenna electrode of the invention. In various embodiments, the antenna electrode is described as being incorporated in various devices, such as, RF ablation catheters, microwave ablation catheters, intramyocardial injection catheters, thermoacoustic imaging catheters, magnetic resonance imaging (MRI) catheters which enable delivery of ablation energy and transmission/receiving of MR signals, all of which have the ability to enable monitor lesion assessment in real-time. However, the device of the invention need not be configured to ablate tissue but rather solely monitor the state of biological tissue. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. References to “the method” includes one or more methods, and/or steps of the type described herein which will become apparent to those persons skilled in the art upon reading this disclosure and so forth. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the invention, the preferred methods and materials are now described. FIG.1illustrates a conventional steerable cardiac RF ablation catheter with the ablation electrode at the distal end and handle at the proximal end. During an intracardiac RF ablation procedure for treatment of cardiac arrhythmias, an ablation catheter is introduced in the cardiac chamber via the venous approach and a ground pad is placed on the skin to complete the RF circuit. The ablation electrode is placed in contact with the cardiac tissue to be ablated and RF energy is delivered to the tissue to be ablated. Passage of a high frequency alternating current into the tissue causes local thermal injury, killing the tissue in contact with the electrode to create an ablation lesion, which results in conduction blocks. To ensure controlled thermal injury to the myocardial tissue, the ablation electrode needs to be in good electrical contact with the myocardial tissue and the ablation procedure needs to be monitored till desired depth of tissue is ablated. To monitor the cardiac ablation procedure, the inventors have redesigned the ablation electrode of the cardiac ablation catheter as a RF/microwave antenna. The reflection transmission electrical properties of the antenna electrode of the disclosure in the frequency domain during the duration of the ablation procedure is assessed to monitor procedure parameters and assess lesion formation, i.e., confirm electrode-tissue contact, confirm RF energy delivery to tissue, and confirm and assess lesion formation, i.e., depth of the lesion/tissue ablated, rate of ablation to ensure safe ablation and avoid excessive RF ablation. FIG.2Ais a schematic of an antenna electrode10in one embodiment of the invention where the antenna electrode is a spiral antenna electrode40. The spiral antenna electrode has a spiral positive plane15which is a helical spiral with each spiral separated by a dielectric30. The positive spiral15is surrounded by a ground plane20separated by a dielectric30.FIG.2Bshows a schematic of the spiral antenna electrode40on a tissue1000and electromagnetic model of tissue being ablated.FIG.2Cshows characteristic return loss300and phase angle310response in the frequency domain from 85 MHz to 2 GHz in a physiological saline solution using antenna electrode10. Note the 180° phase shift that occurs at the resonant frequencies320at 350 MHz and 1000 MHz. As the dielectric properties of the medium surrounding the antenna changes, the return loss and phase angle profiles in the frequency domain change, and the resonant frequencies change as well. White arrows indicate the direction of shift in resonant frequencies as the dielectric properties of the medium change. By monitoring the return loss, phase angle profiles of the antenna electrode in the frequency domain and changes in resonant frequencies during the ablation procedures, the procedure parameters can be inferred and lesion formation can be monitored and assessed. FIG.3illustrates a prototype spiral antenna electrode40incorporated into a steerable catheter70for performing percutaneous intracardiac RF ablations. The distal deflectable section and spiral antenna sensor electrode are shown in the inset. A coaxial cable50runs along the length of the catheter70and connects to the interface circuit including low pass filters, high pass filters, RF generator and vector impedance network analyzer, to simultaneously deliver high frequency sensing signals (MHz-GHz) to and from the antenna electrode and low frequency ablation RF (KHz) to the tissue via the electrode, and a very low frequency (DC) endomyocardial electrogram (EEG) signal from the myocardium to the EEG recording system. The antenna electrode of the invention is configured to output energy that ablates tissue. The terms “ablate” or “ablation”, including derivatives thereof, include, without limitation, substantial altering of electrical properties, mechanical properties, chemical properties or other properties of tissue. The term electrode within the context of “antenna electrode” includes a discrete element, such as an electrode, or a plurality of discrete elements, such as a plurality of spaced apart electrodes, which are positioned so as to collectively treat a region of tissue or discrete sites. One embodiment of an antenna electrode emits energy that ablates tissue, i.e., cardiac tissue, when the element is coupled to and energized by an energy source. Examples of energy emitting ablation electrodes include, without limitation, electrode elements coupled to direct current (DC) sources or alternating current (AC) sources (e.g., radiofrequency, RF, current sources), antenna elements energizable by microwave energy sources, pulsed high voltage sources, heating elements (e.g., metallic elements or other thermal conductors which are energized to emit heat via convective heat transfer, conductive heat transfer, and the like), light emitting elements (e.g., fiber optics capable of transmitting light sufficient to ablate tissue when the fiber optics are coupled to a light source), light sources (e.g., lasers, light emitting diodes, and the like), ultrasonic elements such as ultrasound transducers adapted to emit ultrasound waves sufficient to ablate tissue when coupled to suitable excitation sources), combinations thereof and the like. As used herein, the term “ablate,” including variations thereof, is construed to include, without limitation, to destroy or to permanently damage, injure, or traumatize tissue. For example, ablation may include localized tissue destruction, cell lysis, cell size reduction, necrosis, or combinations thereof. In some embodiments, the ablation device may be connected to an energy generator (e.g., RF) by electrical conductors within the shaft of the ablation device or otherwise incorporated into the ablation system. RF energy may be outputted to a desired frequency based on the treatment. Example frequencies include, without limitation, frequencies in the range of about 50 kHz to about 1000 MHz (e.g., 300 to 700 kHz). When the RF energy is directed into tissue, the energy is converted within the tissue into heat allowing the temperature of the tissue to be increased, for example to a range of 40° C. to about 99° C. In some embodiments, a temperature sensor may be used to monitor the temperature of the target tissue to confirm therapeutic delivery of RF. A temperature sensor may also be used to monitor temperature of non-target tissue to reduce or avoid iatrogenic injury. While the device of the antenna electrode of the invention is described generally with reference to use of RF, the antenna electrode described herein can be used for Microwave Radiometry applications and therefor may be connected to an energy generator that generates microwave energy, e.g., energy having a frequency of between about 300 MHz and 300 GHz. In some embodiments the ablation electrode may be an RF electrode in monopolar configuration with a dispersive grounding pad on the patient's skin to complete the electrical circuit. In other embodiments, the configuration of the RF electrode may be bipolar. Ablation energy may be radiofrequency electrical current having a frequency up to 1 MHz, 50 MHz or 100 MHz or in a range of about 300 to 1 MHz or about 300 to 700 kHz and a power in a range of about 1 to 50 W. The delivery of RF energy may be controlled by an energy generator associated with a controller that uses temperature feedback from a sensor associated with the system. In some embodiments the antenna electrode functions to emit a substance as an ablation agent. In such embodiments the system may further comprise a means to inject the substance such as a manually operated syringe or automatically controlled pump. The emitted substance may be saline, phenol, ethanol, botulinum toxin or other neurotoxins, anesthetic agent, including but not limited to depolarizing or non-depolarizing agents, such as marcaine, bupivacaine, lidocaine, or other anesthetic agents, and other agents capable of reducing nerve signal transmission. FIGS.4A-4Cprovide schematics of various configuration of coaxial sensors. Schematics shown inFIGS.4A and4Bdepict positive plane15and circular ground plane20of the coaxial sensor separated by dielectric30. The surface areas of the positive plane, ground plane and the separation between them can be varied which affects the return loss characteristics in the frequency domain.FIG.4Cshows a coaxial sensor with an intermediate floating plane25which is not connected to either.FIG.4Dshows characteristic return loss versus frequency profiles for the coaxial antenna sensor electrode ofFIG.4Bin saline solutions of concentrations ranging from DI water to 1.1% saline. No distinct resonant frequencies can be seen, making it difficult to implement this design in an antenna electrode configuration. FIG.5Ais a schematic of a spiral antenna electrode40with a spiral positive plane15where each strut is separated by a dielectric30and surrounded by a ground plane20; again separating the ground plane and the spiral is a dielectric. The spiral acts as an inductor and the stray capacitance between the struts and between the positive plane and the ground plane, results in giving this antenna a characteristic return loss profile with a resonant frequency.FIG.5Bshows the return loss versus frequency profiles for the spiral antenna electrode40in saline solutions of concentrations ranging from DI water to 1.1% saline. The spiral antenna electrode of this design has a distinct resonant frequency at about 1400 MHz for all concentrations of saline solution. However, as the saline concentration increases the return loss decreases at lower frequencies; particularly between 10-500 MHz. The spiral antenna electrode's reflection properties in the frequency domain are a function of electrical properties of the medium, i.e., conductivity and permittivity of the medium can be used to monitor RF ablation procedures and assess lesion formation in embodiments of the invention. FIG.6shows the schematic setup of the system of the invention used to evaluate ablation lesion assessment performance of an antenna electrode disposed in a catheter in an animal. FIG.7show the schematic of the RF ablation lesion assessment system of the invention for performing intracardiac RF ablation procedures. The ablation RF generator provides ablation RF energy in the 1 KHz to 1 MHz range. The network analyzer measures the reflection electrical properties of the antenna electrode in MHz and GHz ranges. Interface circuit comprises a low pass and a high pass filter. The output of the RF generator passes thru a RF low pass filter or a band pass filter to allow only the ablation frequencies to pass through and attenuates all other frequencies by over 40 dB, thus preventing transmitting frequencies which interfere with high frequency network analyzer signals and measurements. The input and output of the network analyzer passes thru a high pass filter or a suitable band stop filter, which attenuates the ablating frequency by over 40 dB thus preventing any damage to the sensing hardware and has minimal insertion loss at all other frequencies. The vector network analyzer sends an incident signal to the antenna electrode in the MHz-GHz frequency range; the difference in amplitude and phase of the transmitted and reflected signals are used to compute the return loss and phase angle properties of the antenna electrode in the frequency domain. These are processed and recorded via a computer or other hardware, and displayed during clinical use to monitor the procedure and assess and monitor lesion formation. In various embodiments, the system includes a low pass and high pass filter which may be band pass/band stop filters and an RF generator that has a range of about 10 Hz to 100 MHz. FIGS.8A-8Cshow the return loss and phase angle responses of the spiral antenna electrode40in the frequency domain when in blood (FIG.8A), in contact with epicardial tissue (FIG.8B) and in contact with fatty tissue section on the epicardium (FIG.8C). During clinical use the catheter with the antenna electrode40is advanced in the cardiac chambers. When the electrode is in blood, the characteristic return loss profile300, phase angle profile310, and resonant frequency320, at ˜325 Hz, as shown inFIG.8A, are dependent on antenna electrode design and can change from one design to another. Depending on extent of tissue contact and orientation of contact; this changes as shown inFIG.8Bwith a flattening of the return loss profile300and shift in resonant frequency320to about ˜400 MHz. Depending on the nature of tissue, i.e., fatty or ablated tissue or scar tissue, further increase in resonant frequency might be exhibited. FIGS.9A-9Cshow return loss, phase angle characteristic of the antenna electrode40in a wider frequency range, i.e., 100 MHz to 2 GHz. In this frequency range two distinct resonant frequencies can be observed. Extent of electrode tissue contact may be assessed using one or more resonant frequencies320, e.g., at ˜350 MHz and 1200 MHz (FIG.9A) when the electrode is in blood or saline, which then shifts to 400 and 1500 MHz (FIG.9B) depending on extent of electrode-tissue contact. If the electrode is fully in contact with ablated tissue, the resonant frequency320may shift to 525 and 1700 MHz (FIG.9C). The shift in resonant frequency from antenna-electrode in blood, to antenna-electrode on tissue can be used to determine the antenna-electrode surface area in contact with tissue. During the ablation procedure, it is important to maintain good electrode contact with tissue to ensure RF energy deposition in the tissue. With a moving heart wall this can be difficult and it is important for the physician to confirm RF energy deposition in the tissue. The antenna electrode40shows characteristic return loss and phase angle profiles when RF energy delivery is in blood.FIG.10Ashows a return loss and phase angle profile when antenna electrode is in blood and10B shows the same when ablation RF is turned on (with electrode in blood). When the electrode is in blood, the phase angle reversal/resonant frequency is ˜325 MHz (FIG.10A); when RF ablation is turned on, this phase angle reversal/resonant frequency drops to ˜200 MHz and stays there. This distinct characteristic return loss300, phase angle310and resonant frequency320response (FIG.10B) when RF energy is delivered in blood notifies the physician of the loss of electrode-tissue contact. With reference toFIGS.11A-11E, progression of lesion formation is indicated by the return loss profiles300and phase angle profiles310in the frequency domain at different time points in the ablation procedure. When RF energy deposition in tissue is translated into tissue temperature rise and thermal tissue damage, an ablation lesion is created. This lesion formation process can be discerned by monitoring return loss profiles300, phase angle profiles310and phase reversal frequencies320in the frequency domain during the ablation procedure (FIGS.11A-11E). The return loss300profile is flat when the electrode is in contact with tissue and phase reversal frequency is ˜400 MHz (FIG.11A), on onset of RF ablation phase reversal frequency320drops to 250 MHz and a dip in return loss300is seen at ˜200 MHz (FIG.11B); as ablation progresses phase reversal frequency320increases gradually to 400, 600 and steadies at 800 MHz for this antenna electrode design (FIGS.11C-11E). By monitoring the change in phase reversal frequency320and return loss profiles300, thermal tissue damage can be confirmed. Thus, the return loss profile300, phase angle profile310and resonant frequency/phase reversal frequency320can be used to infer electrode-tissue contact, confirm RF energy delivery to the wall and assess lesion formation. FIG.12shows the relationship between phase reversal frequency/resonant frequency320and lesion depth. The resonant frequency/phase reversal frequency320observed during RF ablation procedure correlates to the depth of the lesion formed (FIG.12) and the nature of the surface of the lesion. The phase reversal frequency observed during ablation can be used to estimate lesion depth under optimized conditions of saline flush irrigation, applied power and estimated electrode-tissue contact surface area. This methodology of using the return loss profiles300, phase angle profile310of the antenna electrode to infer lesion depth can be implemented clinically to monitor and assess lesion formation in the system of the invention. As it can be evidencedFIGS.8-12the return loss profile300, the phase angle profile320, the resonant frequency/phase angle reversal frequency320of the antenna electrode can be used to monitor cardiac RF ablation procedure parameters e.g., confirm and quantify electrode tissue contact, confirm RF energy deposition in blood, confirm lesion formation and assess lesion depth during the procedure. In a typical intracardiac ablation procedure the RF ablation catheter with the antenna electrode of the invention is advanced in the cardiac chambers using x-ray fluoroscopy guidance, with preoperative CT or MRI images. A baseline return loss, phase angle, resonant frequency data set is obtained with the antenna electrode in blood. Then the antenna electrode is contacted to the cardiac tissue in different orientations to get another baseline return loss, phase angle and resonant frequency data set with antenna electrode in contact with tissue. With the baseline data acquired and properties recorded, the physician gets the information on the return loss, phase angle and resonant frequencies that are needed to confirm contact and to quantify the extent of electrode-tissue contact i.e., surface area of electrode in contact with tissue. The ablation catheter is then steered to the anatomical region of interest to be ablated. Using the baseline data when antenna electrode was in blood and tissue, the physician confirms electrode-tissue contact, adjusts the catheter to maximize the contact; and delivers the ablation current into the tissue. Monitoring the resonant frequency changes, ensures that the electrode-tissue contact is maintained for the duration of ablation. By monitoring the resonant frequency progression, lesion formation is confirmed and ablation is stopped when resonant frequency reaches a desired set-point indicative of the lesion depth required at ablation location. Thus the RF ablation lesion assessment system of the invention including an ablation catheter with an antenna electrode, can be used to monitor cardiac RF ablation procedure and assess lesion formation by monitoring the reflection characteristics in the frequency domain via a vector network analyzer. The purpose of the cardiac RF ablation procedure is to create a permanent conduction block. To achieve this it is important to ablate the entire wall thickness of the atria or ventricle safely, i.e., no excessive power during ablation which will cause steam pops or excessive duration of ablation which may cause perforation. To enable this, the RF energy input needs to be closely regulated throughout the procedure and electrode tissue-contact needs to be maintained. RF ablation primarily occurs by ohmic heating, where the tissue in contact with the electrode heats due to the current which passes thru it. This heat is then conducted deeper in the tissue, creating a deeper lesion. If the local tissue impedance rises significantly higher e.g., when tissue is charred, the RF power delivered by the electrode in the tissue is not effectively converted to heat and superficial lesions are created. For better clinical outcomes entire wall thickness of the atria needs to be ablated, e.g., 3-4 mm. To achieve this, local tissue impedance and temperature needs to be regulated at an optimum level i.e., the amplitude of power applied needs to be regulated. The rate of change of phase reversal (from 400 MHz to 250 MHz back to 400 MHz and higher) observed during the ablation procedure is a measure of the impedance of the tissue in contact with the electrode; to make deeper lesions the power level/wattage of RF deposition in the tissue and can be adjusted to hold the phase reversal frequency steady at 400-600 MHz by regulating the power applied. Thus deeper lesions can be created without causing excessive tissue heating, which results in surface charring or steam pops. Since the resonant frequency is held constant between a certain frequency range, resonant frequency alone cannot be used to assess lesion depth. Since lesion depth is also directly proportional to the total energy deposited in the tissue, the total power applied during the entire procedure or the total power applied when the resonant frequency was held constant in the selected frequency range, e.g., 400-600 MHz, may be used to estimate the lesion depth. The complications during the procedure are caused by excessive ablation, i.e., excessively longer duration of ablation and/or by applying excessively high power. The rate of resonant frequency change during RF ablation is an indication of the dielectric properties change and temperature of the tissue in contact with the electrode. During the ablation procedure, there is a significant change in resonant frequency as ablation progresses, and the rate of resonant frequency/phase reversal frequency change is an indication of the rate of change of tissue electrical properties and tissue temperature; which is also a measure of amplitude of power applied. To create deeper lesions safely, the power input rate needs to be titrated which can be accomplished by a controller which monitors the rate of resonant frequency change and accordingly adjusts the power input. Alternately, the power input can be adjusted manually to maintain an optimum resonant frequency change rate. The objective of the cardiac ablation procedure for treatment of complex arrhythmias e.g., atrial fibrillation, is to create contiguous transmural lesions within anatomical boundaries, e.g., around pulmonary vein ostia. The methods described earlier disclose using the RF ablation lesion assessment system of the invention to create lesions of known depths, thus transmural lesions may be created. To create contiguous lesions, the antenna electrode catheter needs to differentiate between ablated tissue and non-ablated tissue. InFIGS.9A-9C, the distinctly different return loss, phase angle and resonant frequency characteristics of the antenna electrode when in contact with blood, tissue and ablated tissue are shown. This feature can be used to identify the tissue type in contact with the catheter. This can be done in a clinical setting by steering the catheter to different points to create electrode-tissue contact, monitoring its return loss phase angle profiles and phase reversal/resonant frequencies to assess tissue type. The RF ablation lesion assessment system may be configured to have two modes, assessment mode and the ablation mode. Since adding RF filters in line will cause added electromagnetic system noise, a switch in the system will enable taking the filters offline and having the catheter directly connected to the network analyzer. The frequency range and amplitude of assessment/sensing signal could be higher for the purpose of assessment as well. The operator will have the option to select the modes; however, when ablation RF is turned on, the system will have an auto switch to ablation mode. To enable tissue assessment, the physician selects the assessment mode then obtains baseline data of return loss, phase angle and resonant frequency characteristics when the electrode is in blood, and contacting known healthy tissue in different orientations. Once this is done, the catheter is steered to the desired anatomical targets and return loss, phase angle, resonant frequency, and the like, properties are recorded; compared to the baseline data to infer tissue type in contact. The system can switch between assessment and ablation modes with a switch; or the ablation mode automatically engages when the RF switch is turned on. FIG.13shows a graphical user interface which can be used to monitor ablation procedures and assess lesion formation. A suitable user interface indicates the different procedure parameters, i.e., area of tissue electrode contact, and the type of tissue in contact with electrode. Additionally, during RF ablation it includes an indication confirming RF deposition in tissue and assessment of lesion formation, i.e., rate of lesion formation and depth of lesion formation. Baseline/Benchmark assessment of different contact conditions are made prior to start of the procedure, e.g., electrode in blood, electrode in contact with tissue in different orientation, and the like. Before ablation, assessing the tissue type as ablated tissue, non-ablated tissue, blood, fatty tissue will be required. This will be done in the assessment mode. These can be indicated as a slide bar/graph with markings for blood, tissue, ablated tissue, and lesion depth are made on the scale, a sliding cursor/arrow indicates the position of the electrode at a given time. Area of electrode in contact with tissue before and during RF ablation needs to be continuously indicated. This can be the actual surface area, % of the area, and the like. During ablation, rate of RF input in terms applied wattage and saline flush rate may be entered in the system for estimating lesion depth and total power input. During the ablation process the rate of RF deposition in tissue will be displayed and quantified. This will be estimated on the total wattage applied, saline flush rate and shift in resonant frequency observed. Lesion progression will be displayed as an estimated lesion depth based on resonant frequency and total power deposited (as estimated from the electrode area in contact, saline flush rate and applied watts). Alerts indicating excessive ablation rate and unsafe surface conditions which will cause steam pops can be included. Besides cardiac ablation, RF ablation is used for treatment of other clinical conditions e.g., nerve ablation for pain management, liver cancer tumor ablation, breast cancer tumor ablation, and the like. In these procedures a needle electrode/probe/device is placed in the tissue to be ablated using X-ray, ultrasound, CT or MRI guidance, it is then connected to the RF generator, a grounding pad is placed on the patient. RF wattage and time duration of RF application is based on physician experience and manufacturer provided estimates of ablation zone under given ablation conditions. The ablation needle-electrodes can be designed as RF/microwave antennae, and by monitoring the change in reflection transmission electrical properties in the frequency domain during the procedure enable infer ablation zone and extent of thermal injury. Devices and methods to intraoperatively access RF ablation zone/lesion, extent of thermal tissue damage and maximize ablation zone are described and included in the invention. FIGS.14A-14Cshow the schematic of the RF ablation needle electrode of the invention as a modified dipole/monopole antenna. This configuration allows to transmit a broad range of frequencies form DC to few GHz to the antenna/tissue. The body of the ablation electrode60is configured as a coaxial cable in the proximal section (FIG.14B) which comprises a core ‘X’ surrounded by a dielectric30with the shield ‘X’ and an outer insulator35. The proximal section is insulated, in the distal end of the shield, e.g., few millimeters section, the insulator is removed, causing this section to acts as the ground plane20of the antenna. The distal section15, is the positive of the antenna which is connected to the core of the coaxial cable at the distal tip of just distal to the ground plane of the antenna. The positive plane of the antenna comprises a helical coil wound on an insulator/dielectric material but has no dielectric or insulation covering the outer surface of the helical coil. The helical coil has closely wound pitch, and each turn is separated by a dielectric30. The width of the turns of the helical coil may be uniform throughout the length of the coil or may vary from proximal to distal; which can potentially affect the sensitivity of the antenna electrode. In another configuration of the same design, the helical coil is replaced by a conductor wire or a tubing. The length of the helical coil and or the wire can vary from 2 mm to 15 cm. It can be straight, curved, shapeable or telescopic to adjust for different lengths and configurations. The ablation RF is delivered to the tissue from the positive plane of the antenna-needle but can be applied from both, the positive and the ground plane as well. FIG.14Cprovides an electrical schematic of the antenna electrode when placed in a tissue. The tissue behaves as a capacitor and resistor in series. During the RF ablation procedure, as the dielectric properties of the tissue change, so do the reflection/transmission properties of the needle antenna electrode and the change used to quantify ablation zone and extent of thermal injury. FIGS.15A-15Dshow a configuration for the RF ablation antenna needle electrode10with the ground plane20located on the outer surface of the body. This increases the sensing signal penetration, as shown by the field lines thru the entire thickness of the tissue (FIG.15BandFIG.15D). This is particularly useful for monitoring ablation of shallow lesions, not further out from the surface of the skin, where excessive ablation can cause burn wounds close to the surface of the skin. The ground plane20may be fixed to the electrode body or can be connected during the procedure by a number of external fixation methods, such as screw on attachments, gripper chucks, gripper jaws, and the like. The ground plane may be a conductor on a flexible dielectric surface, e.g., polymeric or fabric which is glued to the skin by an appropriate adhesive which does not attenuate conductivity. FIGS.16A-16Bshow an RF/microwave needle antenna electrode in one embodiment of the invention which is a combination of a monopole antenna and a dipole antenna with the ground plane of the dipole antenna placed outside the body. The body of the needle antenna electrode is a triaxial cable. This design has one positive15and two ground planes20, one ground plane in close proximity to the positive and one ground outside the body. In one antenna electrode configuration, the core and the inner shield form a monopole/modified dipole antenna. RF for ablation may be delivered to the tissue by the positive plane/electrode or both the positive and ground plane/electrode. The ablation zone is monitored by reflection measurements between the inner monopole/modified dipole antenna and between the positive and the ground plane outside the body. As indicated by the field lines inFIG.16B, this antenna configuration has a wider sensitive region and can be used for shallow and deeper anatomical locations. This configuration provides distinct return loss, phase angle profiles in the frequency domain to monitor local tissue changes between the two antenna combinations simultaneously. The outer ground plane can be made in different forms as described earlier forFIGS.15A-15Dand need not be fixed to the needle antenna electrode. Since in this configuration there are two antenna on a single device and two reflection measurements are made, these can be made intermittently using one or more reflection measurement setups. An analog or digital switch will enable measurements with the two antenna intermittently. FIG.17shows a schematic of the setup to monitor RF ablation zone with the needle antenna electrodes described inFIGS.14-16. This is done by monitoring changes in magnitude and phase of incident and reflection signal, i.e., reflection properties of the needle antenna electrode, i.e., return loss, phase angle in the frequency domain, during the ablation procedure. The ablation RF (500 KHz) generated by the RF generator passes thru a low pass filter to attenuate all non-ablation frequencies, a ground pad placed on the patient completes the ablation circuit. The high pass filter prevents the ablation RF from entering the network analyzer and other measuring electronics, but allows the sensing RF/microwave frequencies to pass from and back to the network analyzer. The network analyzer measures and computes the difference in magnitude and phase of the incident and reflected signal and computes the return loss, phase angle, and the like, in the frequency domain during the procedure and displays the information on the computer/user interface. The electrical properties of these antenna electrodes is a function of the tissue in which the antenna electrodes are placed and the antenna designs, i.e., number of turns, diameter, pitch, dielectric properties, length of the coil, spacing from the ground plane, and the like. As the tissue properties change during ablation, so do the characteristic resonant frequency/phase reversal frequencies, return loss profile and the phase angle profiles. After the RF ablation antenna electrode is placed in the tissue of interest under imaging guidance, the baseline return loss, phase angle and phase angle reversal frequency data is obtained. During ablation the changes to these characteristic properties is monitored and depth of lesion formed/ablation zone, rate of lesion formation is inferred and monitored. These devices will have limitations on depth assessment to a few mms 5-15 mm diameter based on change in resonant frequency changes. To further assess ablation zone, beyond the sensitivity offered by resonant frequency shift, other methods to estimate ablation zone based on total energy deposited are implemented. Namely, estimating the time duration and amplitude of RF energy (wattage) applied over the surface/volume of the tissue. As described earlier, efficacy of RF ablation is a function of tissue properties at the electrode-tissue interface. A corresponding safe return loss, phase angle and resonant frequency conditions at which, there is minimal thermal tissue damage, is determined, and the ablation parameters adjusted to hold this state. This method can be used to ensure no excessive thermal damage occurs to the tissue at the electrode-tissue interface, e.g., charring, water boiling, and the like, which is needed in order to create deeper lesions. By titrating the input RF power levels such that an optimum interface tissue characteristics is maintained to create deep lesions. The total energy delivered to the tissue in these controlled conditions is used to estimate the ablation zone, where the ablation zone is proportional to the total energy deposited. However for this method to be effective, it is important to know if there are any blood vessels which will act as heat sinks. This feature can be incorporated in the user interface depicted herein, where the physician sets the safe level of maximum resonant frequency or the resonant frequency range and time duration of ablation in that range. The controller hardware and software adjusts/titrates the RF input power applied by the RF generator to maintain the resonant frequency range. The methods described above implement monitoring the reflection (S11) electrical properties of an antenna electrode in the frequency domain to monitor RF ablation procedure and assess lesion formation. One of the limitations of these systems is the limited depth of penetration and can be overcome by performing transmission measurements along with reflection measurements. Reflection measurements will be used to monitor rate of tissue property changes in contact to the RF applicator10and the transmission electrical properties will be measured to quantify ablation zone and extent of tissue thermal damage in the volume of tissue being ablated. FIG.18shows the schematic of a system of the invention which performs transmission (S12 and/or S21) and reflection (S11) measurements during RFA procedures to assess ablation zone. The system comprises a needle antenna electrode10which is placed in the tissue to be ablated and receiver coils90which are placed outside the body, e.g., on the surface of the skin. The needle antenna electrode may be a monopole/modified dipole antenna and transmits an electromagnetic signal in the frequency domain, which travels thru the tissue to the external receiver coils90. S11 reflection measurement will provide assessment of tissue directly in contact with the electrode and the S12 transmission properties will provide assessment of the tissue thru which the signal travels to quantify ablation zone and extent of thermal injury. The ground pad to complete the ablation RF circuit is a high impedance pad to prevent high frequencies from coupling to it and getting grounded, or it has a low pass filter inline to the RF generator to prevent high frequency signals from being grounded. Reflection electrical properties, e.g., return loss, phase angle, reflection coefficient, of the needle antenna electrode10will be measured in the frequency domain to assess tissue properties in contact with the needle antenna electrode. The transmission electrical properties between the needle antenna electrode and surface receiver coils, namely changes in amplitude and phase of the signal transmitted, before and during ablation are monitored to assess the ablation zone and extent of thermal tissue injury. The reflection and transmission assessment is performed by a vector network analyzer capable of both measurements. Also the transmitted signal can be measured by other equipment, e.g., spectrum analyzer, which will measure the amplitude and phase of the signals received by the surface receiver coils during the ablation procedure. The receiver coil placed on the surface may be one or more receiver antenna coils, tuned to a broad frequency range. These can be simple loop coils, phased array loop coils, spiral antenna arrays, and the like. The signal received by these coils may be measured individually in intervals or as a combined output. Digital and analog switches enable select the receiver coils to be monitored and the time intervals at which the signals to be processed. In case a spectrum analyzer is used, a separate signal generator with an output in a broad range of frequencies can be used to measure transmission properties to assess lesion formation and confirm ablation of cancerous tissue, and the like. It is known that different tumors absorb electromagnetic signals at different frequencies, e.g., breast cancer malignant tissue absorbs RF in the range between 180-400 MHz, which may change with antenna design. An electromagnetic signal in this frequency range may be transmitted by the ablation antenna electrode and the magnitude and phase change monitored during the ablation procedure will be used to ensure complete ablation of the tumor and the margin. The receiver coils placed on the surface of the skin/body need to make good electrical contact with the surface of the skin, so appropriate conductive adhesive will be required. These coils can be various types including loop coils, archimedean spirals, and the like. The coils can be single coils, arrays, phased arrays, and the like designed to receive the high frequency signals transmitted by the ablation antenna electrodes thru the tissue. The output of the receiver coils can be connected to a network analyzer and/or a spectrum analyzer, via a switch where the signal from one or more coils at a time a received and processed. FIGS.19A-19Cshows the schematic of an RF ablation lesion assessment system of the invention implementing reflection and transmission measurement for ablation of anatomies such as breast cancer tumor ablation. During breast cancer tumor ablation procedure, a needle antenna electrode10will be placed in the tumor, at a predetermined location, using ultrasound, MRI or guidance modalities (FIG.19A). The needle antenna electrode will be placed in the tumor such that the entire tumor can be ablated in a single insertion, but may be with retracting the needle to completely ablate the resection zone. The placement of the needle antenna electrode in the anatomy with respect to the tumor is recorded (preoperative or intraoperative images) and ablation zone determined. Presence of heat conducting anatomies such as blood vessels, glands, and the like is noted and recorded. External receiver coils90, which are phased array coils will be placed around the breast, such that they are in good contact with the skin with minimal air pockets, which will affect signal reception (FIG.19B). The needle antenna electrode and external coils are connected to the high frequency measurement equipment, e.g., vector network analyzer, spectrum analyzer, and the like via filter hardware (FIG.19C). Baseline reflection transmission properties with the needle antenna electrode and surface receiver coils is obtained and recorded, which may include return loss, insertion loss, magnitude and phase measured in the frequency domain. The amplitude of the sensing signal for reflection and transmission is typically less than 1 W. After the baseline properties are obtained, RF ablation is turned on and the power level is adjusted such that the resonant frequency of the needle antenna electrode as measured by reflection properties is maintained in the safe mode not to cause excessive temperature rise in the vicinity of the needle electrode, thus maximize the ablation zone. The transmission electrical properties i.e., magnitude and phase of transmitted signal from the needle antenna electrode to the external receiver coils is recorded in the frequency domain during the ablation procedure. Preoperative ablation experiments will guide the ablation lesion/zone determination based on the shift in maximum insertion loss frequency and maximum return loss frequencies. In addition to the frequency sweep assessment, insertion loss in a narrow frequency range may be measured since the breast cancer tumors and other tumors absorb EM radiation in a frequency range of 100-500 MHz (this frequency may change depending on antenna design). Change in insertion loss of these frequencies may imply complete tumor ablation. Similar methods may be used to other ablations, e.g., nerve ablation for pain management, liver tumor ablation, and the like. FIG.20shows the characteristic amplitude profile of the insertion loss between the signal transmitted by the needle antenna electrode10and received by the receiver surface coils90in the frequency range. By monitoring the frequency/frequencies of maximum insertion loss and phase of the signal at the maximum loss frequency/frequencies; the ablation zone and extent of thermal injury is quantified. Return loss/log magnitude v/s frequency indicating coupling between the ablation needle antenna electrode10and the sensing antenna90on the surface. The differential in the coupling frequency from onset of ablation is used to determine ablation zone diameters. FIG.21shows a system setup in one embodiment of the invention which can be implemented to create, monitor and maximize ablation lesions by controlling RF power applied during ablation. The system utilizes monitoring S11 reflection resonant frequency to continue ablating at a safe level and monitoring S12 transmission for assessing ablation zone and extent of tissue damage. The physician sets the safe level of ablation, i.e., the maximum resonant frequency or the resonant frequency range in which to maintain the ablation power input and time duration of ablation. The controller hardware and software adjusts/titrates the RF input power applied by the RF generator to maintain the resonant frequency range. During clinical use the operator will place the needle antenna electrode device10in the anatomical region of interest guided by intraoperative or preoperative MRI, CT, X-ray or ultrasound imaging. Upon placing the needle antenna electrode10in the desired anatomical target, the needle antenna electrode10is connected to the interface circuit comprising RF filters, i.e., low pass and high pass filters, which are in turn connected to the RF ablation generator, network analyzer (or signal generator and amplifier). The surface receiver coils90are carefully placed on the surface of the skin making sure they are in good contact and there are minimal air gaps between the body and the receiver antenna90, and connected to the network analyzer (or spectrum analyzer). A grounding pad is placed in a region away from the ablation zone to complete the RF ablation circuit pathway and connected to the RF generator via a low pass filter. Upon completing the setup, the baseline reflection transmission measurements are performed and data is recorded. The safe ablation window in terms of resonant frequency range is set by the operator in the manual mode or auto control mode, and RF energy is applied. The input RF power levels are regulated/titrated by monitoring the S11 reflection properties of return loss, phase angle and resonant frequency. The ablation zone is assessed by the reflection properties as well as transmission properties (i.e., frequency and phase of maximum insertion loss), and the ablation is stopped after desired ablation target is achieved or a steady state of reflection transmission properties is reached, i.e., ablation zone has reached a steady state. FIGS.22A-22Hsets forth different configurations of antenna designs that can be incorporated for needle antenna electrode configurations shown inFIGS.14-21in various embodiments of the invention. FIG.22Aillustrates a loopless/monopole antenna with a straight positive section. FIG.22Billustrates loopless/monopole antenna with a backward coiled helical positive section. FIG.22Cillustrates loopless/monopole antenna with a forward coiled helical positive. FIG.22Dillustrates a dipole with positive and ground plane co-wound. FIG.22Eillustrates a solenoid antenna with a helical coil connecting positive and the ground. All the antennas fromFIGS.22A-22Hcan be designed with a balun circuit on the shield as shown inFIG.22F, which creates a high impedance and prevents the current leaking on to the shield; only the section of the shield distal to the balloon acts as the ground plane. FIGS.22G and22Hillustrate embodiments of the invention which include a slotted shield antenna and modification for an ablation antenna-electrode. The needle antenna electrode may be configured as a slotted shield antenna, with one or more slots250in the shield along the length of the ablation section of the electrode including coax cable600. The shield extends to the distal end of the antenna electrode, and some sections of the shield removed and the core not insulated to allow for electrical contact with tissue. A coil280may be connected to the core of the coax thru the slots in the shield and the coil280wrapped around the shield with a dielectric between the coil and the shield. Coil280is attached to the core thru the slotted shield with no insulation being on coil280which acts as the positive of the antenna electrode. There is a dielectric under the coil over the shield to prevent direct electrical contact. Ablation RF is applied to both the core and the shield. With this design, the sensitive section of the antenna is in the middle of the ablation zone, and provide better assessment of the extent of ablation zone. Different configurations of the cardiac RF ablation catheter antenna electrode of the invention are described below. Since the ablation antenna electrode has positive and ground planes of the antennae incorporated on the surface of the electrode in close proximity, the base of the antenna electrode is constructed out of dielectric materials. These can be polymeric materials, such as but in no way limited to polyether ether ketone (PEEK), polyimide, ceramic materials, such as alumina, aluminum nitride, and the like. These materials have poor electrical conductivity (very high electrical resistivity) and low dielectric constant (dielectric constant <20), to impart electric and magnetic field penetration in the medium surrounding the antennae. During the ablation procedure, as tissue in contact with the electrode heats, this thermal energy is conducted to the electrode as well, causing the electrode to heat. Electrode temperatures over 43° C. can cause blood coagulation on the surface of the electrode causing high impedance to RF current, preventing tissue ablation. To avoid blood coagulation on the electrode, the electrode needs to be cooled during RF ablation. This is achieved by closed loop saline irrigation or open flush saline irrigation. Open flush saline irrigation is preferred due to its relatively better temperature control due to constant saline flow, which also maintains the tissue surrounding the electrode cool, thus potentially increasing lesion depth. FIGS.23A-23Dshow a configuration in one embodiment of the invention of a modified coaxial antenna electrode. The positive of the antenna electrode15is in the center of the distal surface of the electrode and is about 2-50% of the electrode surface area. The positive15is separated from the remaining electrode surface by dielectric30where the rest of the surface area of the electrode acts as the ground plane of the electrode20. The distal hemispherical surface of the antenna electrode is the sensitive region of the electrode is as shown by the field lines inFIG.23D. The outer surface on the whole, or in part, may be coated with a metallic conductive layer and will function as the ground plane20of the antenna electrode10. This coaxial antenna electrode is sensitive only on the distal surface of the electrode and lacks sensitivity on the sides primarily due to the presence of the ground plane and the field lines from the positive will couple only to the ground plane on the hemispherical side. The ablation RF for the coaxial antenna electrode for this embodiment is delivered to the tissue from the ground plane of the antenna electrode, so the low pass filter circuit will be connected to the shield side of the cable, as opposed to the core. FIGS.24A-24Cshow a coaxial antenna electrode of the invention with sensitivity on the sides. The positive of the antenna15has nodes on the side of the cylindrical side of the electrode to provide sensitivity to the distal spherical surface and the cylindrical side surface (similar to the slotted shield antenna embodiment). One of more positive nodes15can be located on the sides separated from rest of the ground plane20by a dielectric section30. This imparts sensitivity to the sides of the electrode so that RF ablation can be monitored from all sides of the electrode. The five positive nodes, for reflection properties measurement may be connected to a single coaxial cable or each to an individual coaxial cable with a common ground plane, or each to a cable with five cores and a common ground shield. The output of each node may be monitored simultaneously or intermittently. For intermittent measurement, each node may be routed via a digital/analog switch to facilitate measurement and recording the reflection S11 properties in the frequency domain. FIGS.25A-25Bshow a coaxial antenna electrode of the invention with a spiral on the ground plane on the hemispherical surface. The positive plane15is separated by a dielectric30from the ground plane20. The ground plane is configured as a spiral50. One of the limitations of the coaxial sensor with one node or multiples nodes as described inFIGS.23and24is that the return loss profile will be fairly flat in the frequency domain and there is not a distinct resonant frequency/phase reversal frequency to track during the ablation procedure, affecting the sensitivity and specificity of measurements. In order to create a distinct resonant frequency the coaxial sensors described inFIGS.23and24can be configured with a spiral structure50in the ground plane20adjacent to the positive nodes15as shown inFIGS.25A-25B. The spirals50in the ground plane20are connected to the ground plane20from the outside of the spiral and the inner end of the spiral is left open. This adds inductance to the electrode ground plane, thus creating a resonance frequency which can be monitored and tracked during the procedure. For the coaxial antenna electrode designs the ablation RF is delivered from the ground plane of the electrode, but the sensing RF is transmitted from the core or the positive of the antenna electrode. FIGS.26A-26Bshow the coaxial antenna electrode of the invention with positive nodes15on the cylindrical side of the electrode, with the ground plane20configured as a spiral ground plane50around the positive node15. This configuration imparts sensitivity to the sides of the electrode and a characteristic resonant frequency to monitor during ablation procedure. The positive nodes may be connected to one or more individual conductors in a single common ground cable configuration. The spirals on each side may have different number of turns, spacing and strut thickness to provide different electrical characteristics, to enable identify electrode-tissue contact orientation. FIGS.27A-27Eshow an antenna electrode configuration of the invention, where the positive of the antenna electrode15on the hemispherical surface is configured as a spiral-helix where the positive15of the antenna is a helix-spiral40, each turn is separated by a dielectric15and the entire helix-spiral is surrounded by the ground plane20on the distal hemispherical surface of the electrode. This creates field lines as shown inFIG.27Eand potentially increases field penetration in the tissue. The ground plane extends on all the sides of the antenna electrode assembly and continues to the proximal end for connecting to the coaxial cable. The spirals in the positive plane40can be configured in one or more layers, each spiral layer is separated by a dielectric layer and can be arranged one over the other wound in same or opposite directions to increase the penetration or sensitivity of the antenna electrode. FIGS.28A-28Bshow a spiral helix antenna electrode of the invention with one or more positive nodes15on the sides of the electrode as well as on the hemispherical surface, where the positive15of the antenna is arranged as a spiral-helix40on the sides of the cylinder and the hemispherical side. This antenna electrode design imparts sensitivity to distal hemispherical surface as well as to the sides of the electrode. Ablation RF may be delivered to the tissue by the positive plane15or the ground plane20or both the positive plane15and the ground plane20. The low pass filter will be configured to attenuate non-ablating frequencies on the core and the shield accordingly. Spiral antenna electrode with multiple positive nodes on the side; with spiral on the core/positive on the sides. Each positive node may be connected to the same coaxial cable core (positive) or to different coaxial cables, or to a single shielded cable with multiple cores or a multilayer cable (triaxial cable, quadaxial cable, and the like). FIGS.29A-29Cshow an embodiment of the invention in which the antenna electrode has the positive of the antenna15configured as a spiral-helix40and the positive of the antenna15on the distal hemispherical surface is a helical-spiral surrounded by a ground plane20with a gap in the circumference. The positive helical spiral40continues out of the hemispherical surface in this gap in the ground plane and continues as a helix on the sides of the electrode where the positive15is co-wound helically with the ground plane20. This structure provides sensitivity to the entire electrode including the sides. This antenna structure attributes distinct electrical properties due to the helical spiral on the distal hemispherical surface and helical coil antenna structure by the co-wound positive plane and the ground plane spirals on the sides; this enables to characterize orientation of the antenna electrode as it is in contact with the tissue and assess lesion formation. FIGS.30A-30Bshow a spiral helical antenna of the invention with two antennae structures; one connected to the distal hemispherical spiral helical antenna and the other connected to the helical coil dipole antenna on the side of the electrode. Both antennae may have one common ground or separate ground planes. Each antennae may be connected by one or more coaxial cables or triaxial cable. On the distal hemispherical surface positive of the antenna15coiled in a spiral surrounded by the ground plane ring20. On the sides of the electrode, a positive node15is connected to the core of the coaxial cable (as the positive plane15on the distal hemispherical surface) and is coiled in a helix to form a helical antenna. A common ground plane20is on the circumference of the distal hemispherical surface and the circular side edge of the cylindrical side of the electrode. On the cylindrical side, the ground plane is under the helical positive plane and the two are separated by an insulator/dielectric layer. This antenna electrode structure is sensitive on the sides of the electrode and on the distal hemispherical surface. FIGS.31A-31Cprovide yet another embodiment of the antenna electrode design in which the positive15is configured as a spiral helix which starts on the distal hemispherical surface, then continues on the side for some distance. Separated by a dielectric30is a circular ground plane20. A similar design where the positive spiral helix starts on the sides and ends on the hemispherical surface can be implemented. This antenna electrode has sensitivity on the distal hemispherical surface and the sides of the electrode. The pitch, turns and width of the spiral struts and gaps in the spiral struts can be configured to provide a fairly isotropic sensitivity region. This design could be modified by co-winding the ground plane with the positive helical coil on the sides of the electrode in a preferred embodiment. In another configuration of the spiral helix embodiment, the positive and the ground of the antenna are co-wound in an Archimedean spiral helical coil configuration on the hemispherical surface and the sides of the electrode. The positive of the antenna15and the ground of the antenna20are co-wound in a spiral in the hemispherical section of the electrode and then as a co-wound helix on the sides of the antenna. Alternate designs would include, one where both the ground and the positive/core are connected to the coaxial cable at the distal tip; or the core is connected at the distal surface and the ground is connected to the shield at the proximal end. FIG.32shows an electrode of the invention which is configured in a triaxial design with the inner core and the first/primary shield layer being incorporated in the electrode forming one antenna, and the primary/first shield and the second shield forming the other antenna. Each antenna can have the positive or the ground/shield in a coiled, singular meandering configuration. FIGS.33A-33Cdepict an embodiment of the invention wherein the antenna electrode is a solenoid coil antenna with a spiral-helix combination. The core of the coaxial cable is connected to the solenoid spiral-helix coil at the distal hemispherical surface (at the center). The positive of the antenna is then coiled in a spiral on the distal hemispherical surface of the electrode and then continues as a helix along the sides of the electrode-antenna and connects to the ground plane via a capacitor less than 200 pF to block the ablation RF from entering the shield. This capacitor can be placed on the ground plane at other locations as well. This antenna electrode exhibits different resonant characteristics in response to the RF progression. On onset of ablation, the return loss at the resonant frequency gradually increases and flattens to zero as the lesion progresses. The capacitor blocks the ablation RF from going on the ground plane and tunes to a desired frequency. FIGS.34A-34Bdepict an embodiment of the invention having two loop coil antennae electrodes in a quadrature arrangement. The antenna traces on the distal surface can be spiraled to provide resonance or add to the inductance. These antennae can be saddle coils with an overlapping section and other antenna configurations. With these antennae coil electrodes ablation assessment can be carried out in S11/S22 reflection mode and S21/S12 transmission mode simultaneously. Other coil configurations with similar arrangements can be envisioned, e.g., with coiled traces, zig-zag traces, co-wound/coiled traces, traces in opposite directions, and the like to increase connecting field lines and coupling. Each coil may be connected by separate coaxial cables; or a triaxial cable with common ground conductor. In the various embodiments described herein, the ablation antenna electrode of the invention having positive and ground planes incorporated on the surface of the electrode in close proximity, the base of the antenna electrode is constructed out of dielectric materials. These can be polymeric materials, e.g., polyether ether ketone (PEEK), polyimide, and the like, or ceramic materials, such as alumina, aluminum nitride, and the like, which have poor electrical conductivity (very high electrical resistivity) and low dielectric constant (dielectric constant <20), to impart electric and magnetic field penetration in the medium surrounding the antennae. During the ablation procedure, as tissue in contact with the electrode heats, this thermal energy is conducted to the electrode as well, causing the electrode to heat. Electrode temperatures over 43° C. can cause blood coagulation on the surface of the electrode causing high impedance to RF current, preventing tissue ablation. To avoid blood coagulation on the electrode, the electrode needs to be cooled during RF ablation which is achieved by closed loop saline irrigation or open flush saline irrigation. Open flush saline irrigation is preferred due to its relatively better temperature control because of the constant saline flow, which also maintains the tissue surrounding the electrode cool, thus potentially increasing lesion depth. In various embodiments, the ablation electrode base component is fabricated out of ceramics or polymers, or composite construction involving metal and dielectric layers with lumens for saline flush. The antenna structures are then build on this dielectric base structure. The base part comprises a cylindrical electrode base structure with a hemispherical distal surface to provide smooth contact with the tissue to be ablated. As shown inFIG.35, saline flush lumens are fabricated to provide open saline irrigation. The saline flow is induced by a pump placed externally (typically a closed loop with the RF ablation generator so that the pump turns on when RF is applied) and delivered to the electrode via saline flush input ports. A thru lumen in the center provides access to connect the coaxial cable to the positive of the antenna. The ground plane of the antenna extends thought out the outer surface of the base component where the coaxial cable is connected. The distal surface and the side are typically in contact with the electrode to deliver ablation RF into the tissue. The antenna electrode is fabricated in multiple steps/stages; initially a base structure out of a dielectric is machined or fabricated. The saline flush lumens, lumen to connect the positive of the antenna and the ground plane to the coaxial cable provided. Ports and lumens to house the thermocouple, positive plane nodes, and the like will be incorporated in the base structure. The ground plane and the positive plane components are then created on the substrate of conductive biocompatible metals, e.g., gold, SS316, and the like, by various means. In one method the conductive elements of the antenna are sputtered, coated. In another method they are fabricated, machined, cast, or electrodeposited and then assembled on the ceramic/polymeric base. Open saline flush irrigation are utilized to cool the electrode and adjacent tissue during ablation. Since saline is a conductive solution (due to Na+ and Cl− ions) flowing saline solution can act as a long conducting wire and induce noise in high frequency measurement. To overcome this, the inner surfaces of the saline flush lumens have a dielectric coating and the exit ports on the surface of the electrode have a dielectric rim around them. This prevents direct saline contact with the conductive surfaces when held against the tissue. With reference toFIG.35, the antenna electrodes are then assembled in a steerable catheter body700which includes a braided tubing with varying stiffness, and a pull wire anchored in the distal section and connected to the actuation mechanism in the handle section at the proximal end to enable deflect and steer the catheter in desired orientation. A fiberoptic temperature sensor570or a thermocouple is embedded in the electrode and bonded with thermally conductive but dielectric adhesives. Similarly the tubing to deliver saline flush550to the electrode are connected/bonded to the proximal end of the electrode. The core of the coaxial cable600is connected to the positive of the antenna via a hypotubing subassembly which runs in the electrode central lumen and the shield is connected to the ground plane and may be crimped to the ground plane structure. The entire electrode, thermocouple, potentially contact force sensing structures are incorporated in the steerable catheter then connected to a connector comprising pins for thermocouple and other sensing electrodes and a coaxial connector for the ablation electrode. The system is ready for use after appropriate sterilization processes. In another embodiment as shown inFIG.36, the spiral antenna electrode may be deposited on a balloon800of a balloon catheter. The circuit may be deposited directly on the balloon by sputtering or chemical vapor deposition methods; or fabricated and bonded to balloons. During clinical use the balloon may be advanced to the location of therapy, dilated with a fluid medium, e.g., oil, fat, gas, to open the balloon and to position the antenna electrode structure against the tissue to be ablated. In another embodiment as shown inFIG.37, intramyocardial/transendocardial injection catheters are used to deliver therapeutics to the cardiac tissue, e.g., warm saline for ablation, cell therapies, ablative agents, simultaneously injecting warm saline and ablation RF for creating deeper ablation lesions, and the like. The antenna electrodes can be modified by incorporating a central lumen to house the injection needle. The needle may or may not be electrically a part of the antenna electrode. It may be inductively or capacitively coupled to the antenna electrode. As shown inFIG.37, the catheter includes a proximal section made of stiffer braided tubing for imparting longitudinal stiffness, and a softer distal section. A pull wire runs along the length of the catheter, to enable deflect the distal section. The distal end of the pull wire is anchored towards the distal end of the distal section of the catheter. At the proximal end, the pull wire is fixed to the actuator in the handle section. The actuation mechanism moves the catheter body with respect to the pull wire deflecting the softer distal section of the catheter. The antenna electrode design for use with an intramyocardial injection catheter is shown inFIG.37also. A central needle lumen in the electrode houses the needle, at the proximal end of the electrode, the central lumen is connected to a polymeric nonconductive tubing which runs along the length of the catheter and houses the needle. The needle is a composite metal-polymer tubing, with the distal 0.5-2 cm of the needle being metallic and the remaining length being a non-conductive material, e.g., polymeric. This is so that, the needle and the tubing are not a part of the antenna and do not influence return loss and phase angle measurements. The inner surface of the needle may be coated with a polymeric layer to prevent direct saline contact and prevent electrical conductivity of the saline from affecting antenna properties. The needle tip position with respect to the distal tip of the catheter can be manipulated by moving the needle at the proximal end of the catheter. During an intramyocardial injection procedure, the catheter will be advanced into the cardiac chambers via suitable vascular access using imaging guidance. The distal tip of the catheter is placed opposed to the tissue so that the distal surface of the antenna electrode is in contact with the myocardial wall. This will be confirmed by monitoring the return loss, phase angle and resonant frequency of the antenna electrode. After the catheter tip is positioned at the location against the tissue, as confirmed by the return loss, phase angle resonant frequency, the needle is advanced out of the catheter and catheter-wall contact is ensured. When needle placement in the tissue and depth of needle in the tissue is confirmed, a contrast test injection may be delivered. The therapy/injectate is then delivered into the myocardium, and depending on the electrical properties of the injectate, the injection in the wall can be confirmed by changes in return loss, phase angle profiles of the antenna electrode. The intramyocardial injection catheter with antenna electrode may be used to simultaneously perform RF ablation and inject saline or other injectate at the same time using monitoring techniques described earlier. The antenna electrodes implemented in cardiac RF ablation catheters and intramyocardial injection catheters as disclosed herein, can be modified for use in MRI environment to enable MRI guided procedures with design, material and layout changes. The antenna electrode will be configured as a receive-only or transmit-receive coil by matching tuning of the antenna electrode to the MRI's Larmor frequency. Since MRI involves obtaining signal from the hydrogen proton in water molecules, interventional devices are not conspicuous in MRI. Transmit-receive or receive only antennae may be incorporated in the devices to render them conspicuous in MRI. For use in MRI, all the antennae will be tuned to the Larmor frequency of MRI, e.g., 64 MHz for 1.5 Tesla field strength, 128 MHz for 3 Tesla field strength. This enables the antennae to receive or transmit-receive NMR signal generated by the hydrogen proton during a scan. These signals picked up by the antennae are transferred to the scanners receiver amplifiers via an interface circuitry, which includes a matching tuning and decoupling circuitry. The MRI scanner's signal processing system displays these signals into images which are then seen on the scanner consoles. The static magnetic field and RF fields generated during MRI imaging process pose significant safety hazards and interventional devices need to be designed to make them safe for use in MRI. To make the devices safe for use in MRI's static magnetic field environment, the catheters and its components are fabricated out of non-ferromagnetic/magnetic materials. This eliminates the undue/undesired mechanical forces being exerted on the catheters due to the static magnetic field, which could pose hazards to the patients and the operators. During MR imaging, in order to obtain an image, the subject/patient is subjected to intense RF fields at Larmor frequencies, e.g., 64 MHz for 1.5 Tesla and 128 MHz for 3 Tesla. This applied RF induces local electric fields in the patient's body. An interventional device having a long linear metallic/conductive component, when placed in this electric field couples to the E-fields, voltage is induced in the device, which in turn drives a current which is deposited in the tissue in contact with the device, typically at the ends of the device, causing irreversible thermal injury. To render interventional devices safe in MRI the long linear components of the catheters/devices need to be replaced with nonconductive polymeric or ceramic components. If long metallic components are required, they need to be designed in a way to impart high impedance at MRI's Larmor frequencies. For the RF ablation catheters and intramyocardial injection catheters of the invention, the long linear components which will pose MRI safety risks are the pull wire, coaxial cables, wires which connect to the ablation antenna electrode, sensing electrodes and the braiding in the catheter body. The coaxial cables may be arranged with intermittent chokes or windings such that the impedance on the shield of the wound coaxial cables exceeds 50 ohms/cm at Larmor frequencies when measured by a common mode measurement. The diameter, pitch and turns of the coaxial cable chokes can be adjusted to obtain this impedance. In embodiments, one or more coaxial cable chokes will be incorporated along the length of the catheter; typically the length of each choke will be shorter than 10 cm for 1.5 Tesla and 5 cm for 3 Tesla field strengths to minimize coupling to local E-fields. The length of the chokes, diameter and pitch should be adjusted so as to get over 300 ohms impedance over the entire length of the choke, but keeping the overall length shorter than 9 cm for 1.5 T and 4.5 cm for 3 T field strengths. The overall length of the coaxial cables will typically be an odd multiple of 214 (quarter wavelength) for ease of decoupling by a pin diode. FIG.38illustrates a braided section of catheter tubing in one embodiment of the invention. The metal braiding used in catheter tubing includes two or more flat or round wires braided in sets of two such that wires crisscross and overlap one over the other, creating a thick weave and impart longitudinal column strength, rigidity and longitudinal flexibility at the same time. Such a braided wire structure acts as a long linear conductor, since all the wires are electrically connecting each other on every wind, posing significant RF safety risks when used in MRI. To make the braided section of the catheter safe for use in MRI, a braiding with 2 or more wires where at least half the number of wires have an insulating/dielectric coating on them to prevent electrical contact with each other, are wound/braided with pitch and diameter such that each individual wire in a braided section will have an impedance exceeding 25 ohms/cm at the Larmor frequency when measured in the common mode. Further, in a length shorter than quarter wavelength for a bare wire, i.e., shorter than 10 cm for 1.5 T and 5 cm for 3 T, an individual braided wire will have an impedance peak exceeding 300 ohms at Larmor frequencies, i.e., 64 MHz for 1.5 T and 128 MHz for 3 T. No wires in the braid are in direct electrical contact with each other and the overall assembly is insulated in a dielectric coating. The insulating coating could be varnish, lacquer, polyimide and other polymers. Another method, would be to create a dissipative shield, where a section of the braiding may be completely uninsulated, so that it is in direct contact with tissue. This dissipates the induced currents over a large surface area causing minimal tissue thermal injury. FIG.39illustrates an MRI active cardiac ablation catheter of the invention. The catheter includes an antenna electrode, connected to a coaxial cable with one or more intermittent chokes to transmit and/or receive NMR signals. The catheter includes a wire with multiple RF suppression chokes for transmitting ablation RF or a polymeric tube to house the injection needle. The assembly is housed in a metallic braided tubing or a polymeric tubing; where each braid wire is individually insulated and the braid wires arrange in a pitch and diameter such that each wire has an impedance over 50 ohms at NMR frequencies. Alternately an entirely polymeric steerable catheter may be implemented as well. A non-polymeric pull wire enables deflect the distal section and steer and torque. The match and tune circuit interfaces the output of the antenna to scanner receivers frequencies and can be incorporated in the distal section close to the antenna electrode or in the proximal handle section of the catheter. Since, it is known that tissue under ablation changes electrical properties during the ablation processes; different matching-tuning strategies can be implemented so that the electrode MRI signal changes with tissue contact, RF delivery to tissue and lesion progression. Auto tuning approaches may be implemented; which may better enable monitor and assess lesion formation. Monitoring reflection electrical characteristics of the antenna-electrode by a network analyzer during RF ablation can be done by filtering out all frequencies little over the Larmor frequency. FIG.40illustrates an MRI active injection catheter of the invention. The antenna electrode10is connected to a coaxial cable with one or more intermittent chokes, where each choke has an average impedance of over 50 ohms/cm when measured on the shield in the common mode at MRI frequencies. The center of the electrode is connected to a polymeric tubing which houses the injection needle assembly. The injection needle assembly may be permanently incorporated in the catheter or may be removable to function as a guidewire lumen to facilitate advancing the catheter in the left ventricle. The needle is a composite needle, where the distal 0.5 to 2 cm of the needle is made of an MRI compatible metal and rest of the length is made of a polymeric tube; this is to prevent the needle component from acting as an MRI antenna and confounding the signal. The conductive end of the needle may be in direct electrical contact with the antenna electrode so as to visualize the needle in the MRI image as it advances out of the catheter and retracts back in the catheter. During use in MRI, the intramyocardial injection catheter, the ablation catheter and other needle-electrode catheters may be used in combination with other external coils to receive NMR signals. Since these catheter coils will be connected to separate receiver channels, the signals from these devices may be color coded to make the devices conspicuous in MRI and trackable as well. FIG.41is a schematic of a layout using the antenna electrode catheters for microwave ablation. The ablation catheter with the antenna electrode is connected to a signal generator, which generates an electromagnetic signal in a narrow band or a broad frequency range which may remain constant during the ablation procedure or change as the ablation progresses. The output of the signal generator is amplified by the amplifier and the directional coupler measures the amplitude of transmitted and reflected frequencies to and back from the antenna electrode. A controller may be implemented to adjust the ablation signal frequency as the ablation progresses so as to minimize reflected energy and deposit maximum energy in the tissue to create deeper necrotic lesions. Since microwave energy ablation is not based on ohmic heating, as like low frequency RFA, adjusting the input frequency to match the antenna electrode's resonant frequency, will enable deposit more energy in the tissue. This will be safer, since ablation can be carried out at lower power levels. FIG.42is a schematic of a thermoacoustic imaging system, where microwave energy pulse of a short duration may be delivered alongside low frequency RF current. A high frequency microwave pulse over 900 MHz frequency will generate acoustic noise in the tissue. This acoustic noise may be intercepted by intracardiac or external ultrasound transducer devices, e.g., intracardiac ultrasound imaging and sensing catheter, transesophageal catheter, and the like. Signal processing algorithms will analyze the thermoacoustic signals to distinguish between ablated and non-ablated tissue. Although the invention has been described with reference to the above example, it will be understood that modifications and variations are encompassed within the spirit and scope of the invention. Accordingly, the invention is limited only by the following claims.

11857254

In order to characterize the visual system of a subject, a visual test for measuring the sensitivity to contrast of the visual system of the subject is used. For obtaining a predetermined response model of a visual system that gives the element or the internal noise source predominantly limiting the sensitivity to contrast as a function of the luminance and of the spatial or temporal frequency of the visual signal provided by a visual pattern, measures of the impact of internal noise of the elements should be done and the above mentioned visual test can also be used for that purpose. This response model is the expression of the law of the elements of the visual system that relates the sensitivity to contrast to the luminance and to the frequency. The response model is based on the symbolization of the visual system as schematizedFIG.5. The response model is here limited from the transduction by the photoreceptors with their photon noise to the neural processing that is, in this example, separated in two elements with their related internal noises: early neural noise and late neural noise. Other types of symbolization of the visual system may be possible. More particularly, considering the three elements of the visual system, for measuring the levels of photon, early and late neural noises, the technical solution consists in measuring the impact of various sources of internal noises of the subject. This is possible by studying with a visual test, the evolutions of the sensitivity to contrast of the subject with the variations of luminance intensity and spatiotemporal frequency. Such a method is for example documented in the article “Internal noise sources limiting contrast sensitivity” (Silvestre, Arleo & Allard, 2018). An example of a visual test that measures the sensitivity to contrast, the measures being static or dynamic, of the visual system of the subject and the means to obtain the internal noises are now described. Said visual test can be a static visual test where static visual patterns having different spatial frequencies and with varying luminance levels and with varying levels of visual degradation of the visual patterns are shown to the subject to produce the measures of the sensitivity to contrast. It can also be a dynamic visual test where dynamic visual patterns having different temporal frequencies and with varying luminance levels and with varying levels of visual degradation of the visual patterns are shown to the subject to produce the measures of the sensitivity to contrast. The visual degradation is created by adding an external noise to the visual pattern. Note that in the dynamic visual test, the patterns can also have a specific frequency or different spatial frequencies. Most usually and preferably, the visual tests are performed with visual patterns that each have a spatial and a temporal frequency value, and it is possible to set one of the two values to 0. For a static visual test, the temporal frequency is then set to 0. For a dynamic visual test, the spatial frequency is typically set around 0.5 cpd, but rarely set to 0. Such a visual test is performed in multiple steps where the sensitivity to contrast of the subject is assessed by assessing his/her contrast threshold as a function of an external noise added to the visual pattern for a given luminance level and a given spatial or temporal frequency of the visual pattern and this is repeated over ranges of luminance levels and frequencies. To measure the impact of an internal noise source, contrast threshold can be assessed as a function of external noise contrast. If the internal noise has more impact than the external noise, then the external noise will be negligible and have no impact on contrast threshold. On the other hand, if the external noise has more impact than the internal noise, then it will affect performance. More precisely, consideringFIG.1, the flat, left portion of the black curve shows that the external noise has no or a negligible impact on contrast threshold and, on the other hand, on the right portion of the black curve ofFIG.1, the rising contrast threshold shows that the external noise starts to have an impact and overpass the internal noise. Thus, at the breaking point between the two left and right portions ofFIG.1, at which the external noise starts to affect contrast threshold, the internal and external noises have the same impact. At that breaking point, the impact of the internal noise is the same as the impact of the external noise and is the equivalent input noise. Such an assessment of the contrast threshold is done for a given spatial and temporal frequency and for a given luminance level. One can thus understand why a complete/whole visual test for assessing the sensitivity to contrast of the visual system of the subject, for which many frequencies and many luminances should be assessed is a rather lengthy and cumbersome test. It is important to note that the black curve ofFIG.1can be segmented in two: a sensibly flat/constant value portion on the left and a sensibly constant slope portion on the right. Thanks to that, it is possible to compute such a curve for a subject with only at least two measurements: at low level or, better, no external noise for computing the left portion of the curve and at high external noise level, impacting and impairing the sensitivity, for computing the right portion knowing, from previous study on subjects, the parameters, notably slope, of the right portion estimated as a linear part. For that purpose, a model of the curve is preestablished in the form of a predetermined static or dynamic sensitivity model linking/relating the sensitivity to contrast as a function of the external noise and that was preestablished, preferably, on a general or specific population of subjects or a reference subject. In another embodiment, it is also possible to use a more general sensitivity model in which the equivalent input noise is defined as a function of spatial frequency, temporal frequency and luminance intensity. Such sensitivity models may be implemented, for example, in one or more mathematical formulae, data tables, chart . . . or any other forms that could be stored and/or used by a computer for computations. Other types of estimations than the linear one may be used, separately for each portion, or globally for the whole curve. Not only the curve can be computed from only two measures, but also the breaking point and thus the equivalent input noise that quantifies the impact of the internal noise. This simplification of the contrast threshold assessment with only two measures, low or null external noise and high external noise, is implemented with a predetermined static or dynamic (according to the case) sensitivity model linking/relating the sensitivity to contrast as a function of the external noise. Applying the two results of the two measures to the predetermined static or dynamic sensitivity model allows the computation of the above-mentioned curve and (or directly) the equivalent input noise. The sensitivity model can be implemented to produce the curve or directly the equivalent input noise and thus the internal noise. The predetermined static or dynamic sensitivity model can be preestablished for all luminances and frequencies of multiple predetermined static or dynamic sensitivity models can be preestablished for specific ranges of luminances and frequencies. A computer can thus be programmed to give directly the impact of the internal noise from the results that are the two assessed/measured contrast thresholds, of the two measures at low or null and high external noise level, for a given spatial or temporal frequency and for a given luminance level. One can thus easily understand that the use of a simplified contrast threshold assessment with only two levels of external noise in two measurements, one of which being null in a possible implementation, can reduce the duration of the visual test and simplify it very efficiently as compared to a total contrast threshold assessment in which a complete scan/range of levels of the external noise is implemented/tested. By making such contrast threshold assessments and collecting equivalent input noise values for various luminance levels and spatiotemporal frequencies, it is possible to associate an equivalent input noise value as predominantly pertaining to one of the three elements and thus to the photon noise, the early neural noise or the late neural noise. Knowing to which element, receptors or early or late neural circuits, pertains the predominant internal noise, a law or model or a map can be calculated which determines the limiting noise source as a function of various parameters such as luminance intensity, spatial frequency and temporal frequency. Such maps are represented onFIGS.2and3for the spatial frequencies/static contrast sensitivity and for the temporal frequencies/dynamic contrast sensitivity/motion sensitivity respectively. Such a map is in fact a representation of the law of the visual system that relates the sensitivity to contrast to the luminance and to the frequency and that law can also be expressed as a response model. OnFIG.2, four different subjects were tested for their contrast sensitivity and onFIG.3, only two different subjects were tested for their contrast sensitivity. Those maps ofFIGS.2,3give the dominant internal noise source as a function of luminance intensity and spatial frequency, in other words, the internal noise that has the most impact on sensitivity as a function of the luminance and of the frequency. Equivalently, the maps ofFIGS.2,3could instead give the element (the receptors or the early neural circuit or the late neural circuit) that has the most impact on sensitivity as a function of the luminance and of the frequency. It should be understood that this representation on a map is just an example of the possible representations. For example, a map could be made for the elements instead of the noise. Moreover, the related information contained in such a map, here represented in a graphical format, could be represented and stored in other forms and for example in one or more mathematical formulae, data tables, chart . . . or any other forms that could be stored and/or used by a computer for computations. The maps ofFIGS.2and3are two dimensions maps because the element or related internal noise of the response model used is not quantified. OnFIG.4, the map is a three dimensions map because the response model used has quantified the element or, currently, the impact of the internal noise (the equivalent input noise) of the element that predominantly impact/limit the sensitivity to contrast as a function of the luminance and frequency. The previous explanations on the visual tests are given because the invention is also based on a prior knowledge of the internal noise sources that limit the contrast sensitivities and more particularly, the source of noise predominantly limiting the contrast sensitivity for given spatiotemporal frequencies and luminance levels. That prior knowledge is typically established from complete/whole visual tests on a general or specific population of subjects or a reference subject and with implementation of a map giving the dominant internal noise source as a function of luminance intensity and spatial frequency. More generally, this prior knowledge can be implemented in the form of a predetermined response model of the visual system, said predetermined response model giving the visual signal processing element or the internal noise predominantly limiting the sensitivity to contrast as a function of the luminance and of the spatial or temporal frequency. This predetermined map or response model is preestablished on a general or a specific population of subjects or on a reference subject and can be stored in a computer and later used for simplifying and optimizing further visual tests, then referred as optimized visual tests, that are done on individual/specific subjects for diagnostic or prescription purposes. Many deduced data can be obtained from such a predetermined map or response model giving the dominant internal noise. In addition, many further diagnostic or prescription actions may be oriented and optimized based on the predetermined map or response model giving the dominant internal noise. In this context of optimization of further visual test, the response model is preferably obtained from tests on a general or specific population of subjects or on a reference subject. In other cases, a response model can be computed for a specific subject and it could be used as a reference for future visual tests on that subject and/or also simplify/optimize those future visual tests, this is then a personalized response model. The personalized response model can be advantageously computed from an adjustment computation of the predetermined response model or another response model. An example of the use of the predetermined map or response model in the case of prescription is now described. Sunglasses are often used for comfort although they can impair visual perception when the environment is not sufficiently bright. For instance, lower illumination can reduce contrast sensitivity. At high luminance intensities, contrast sensitivities are independent of luminance intensity so it is possible to improve the subject's comfort by reducing luminance intensity without degrading visual perception. However, if the illumination is reduced too much, sensitivity will be affected. The critical brightness at which sensitivity is affected depends on many environmental factors including spatiotemporal frequencies of the relevant visual information the subject will have to visualize in his/her activity, as well as various individual internal factors such as levels of internal noise. The relevant visual information (e.g., spatial frequency, temporal frequency and eccentricity) depends on the subject's activity (e.g., reading, driving, practicing a sport) and can be included to determine the luminance intensity level at which the sensitivity of the subject to the relevant visual information will be affected. For instance, if the subject's activity requires the visibility of low spatiotemporal frequencies in a relatively bright environment, then high-density filters can be used without affecting the sensitivity of the relevant information. On the other hand, if the subject's activity requires the visibility of high spatiotemporal frequencies in a dimmer environment, then high-density filters will likely affect the sensitivity of the relevant information. It can be noted that the critical luminance intensity at which late neural noise is the dominant internal noise source is likely to depend on other variables such as eccentricity and this can be taken into account when performing the visual tests: visual tests can be performed for different eccentricities or directions, or more generally, different retinal locations. Same for colors or light spectrum: visual tests can be performed for different colors. It is then preferable to adapt the prescription of density filter in order to select the optimal density for specific visual functions and conditions which will increase the subject's comfort and minimize his visual sensitivity losses. The prescription may thus concern density filters reducing luminance intensity and, in the context of the invention, this is done according to the subject's sensitivity and in an efficient way. Filter can be active and passive. This approach applies as well as for young, midlife and senior wearers. It can be deduced from the predetermined map that for the conditions under which sensitivity is limited by late neural noise, contrast sensitivity is independent of luminance intensity. In these conditions, luminance intensity can be reduced with a density filter for example without affecting the sensitivity to the stimulus. It is then possible, for an adaptation to the subject, to identify, with an optimized visual test on the subject, the lowest luminance level at which the sensitivity is limited by late neural noise, i.e. at which sensitivity is independent of luminance intensity, to define the filter density that can be implemented without affecting sensitivity or, eventually, minimizing sensitivity losses. That optimized visual test is using a limited range of luminance levels and of frequencies thanks to the predetermined map or response model that gives the ranges of luminance levels and frequencies were the visual test is assessing the relevant element or its internal noise. For a prescription of a density filter, the relevant internal noise to consider is the late neural noise but, for a better adaptation of the prescription, the relevant internal noises to consider are the late neural noise and the photon or early noise and more particularly the boundary between them. Therefore, for an adapted prescription of a density filter, a couple of luminance value and frequency value for the late neural noise can be used or, better, two couples for respectively the late neural noise and the photon or early noise. In addition, the ranges for the visual test can also be adapted to other parameters such as the subject needs. For example, for the adaptation, the range for the frequency used in the optimized visual test can also be selected according to the type of information, low or high frequency, the subject will have to visually observe, and the predetermined map or response model will give the related luminance levels for the visual test and this is still a limited range compared to a whole visual test. The invention can be useful to different segments of population having different levels of internal noise and the predetermined map or response model can be preestablished for a specific segment of population. For instance, the luminance intensity at which it affects contrast sensitivity is increased with aging and thus it is preferable to do optimized visual tests on the older subjects with ranges or values of luminance and frequencies limited according to the predetermined map or response model preestablished on a population of older subjects. If the density filter is not adapted to the subject, it can have a greater impact for older subjects than for younger. The critical luminance intensity at which sensitivity is optimal, i.e. when sensitivity is limited by late neural noise, is higher at high spatiotemporal frequencies. Consequently, if high spatiotemporal frequencies are relevant to the task of the subject, then the luminance intensity cannot be reduced as much. Thus, the activity of the subject with his sensitivity determines the critical level of brightness under which it is preferable that luminance intensity does not drop. For instance, high spatial frequencies are relevant for reading and high temporal frequencies are relevant for playing a highly dynamical sport such as tennis. Thus, in these conditions, the ambient luminance intensity would preferably need to be relatively high so that the limiting internal noise source at all spatiotemporal frequencies is late neural noise. For example, with a luminance intensity above about 350 Td, the limiting noise source is generally late neural noise which would largely preserve the sensitivity to high spatiotemporal frequencies. But for activities that do not necessitate the processing of high spatiotemporal frequencies, e.g. relaxing on the beach, rock climbing or hiking, then luminance intensity could be further reduced to improve the subject's comfort. For instance, a retinal illumination around 35 Td would have little impact on sensitivity to low spatial and temporal frequencies. Note that the critical smallest luminance intensity at which sensitivity to the relevant frequencies is limited by late neural noise can vary greatly with subject ages and, again, an adaptation with an optimized visual test on the subject is most preferable. Given the selected optimal retinal illumination, an active filter can be created to keep the brightness above the critical brightness. The retinal illumination depends on the ambient illumination, the pupil size and the density filter. The pupil size needs to be known around the targeted retinal illumination, e.g. 35 Td in the last example. This can be empirically measured or estimated based on current models. Given the known pupil diameter around the targeted retinal illumination, e.g. 3 mm, then the targeted luminance intensity can be computed. Indeed, the retinal illumination in Td is equal to the brightness in cd/m2multiplied by the pupil area in mm2. Thus, if the target retinal illumination is 350 Td at which the pupil is 3 mm, then the targeted luminance intensity is 350/(pi*(3/2)2)=50 cd/m2. Consequently, if the luminance intensity of the environment is 500 cd/m2, then the density filter should block about 90% of the light for the retinal illumination to be 350 Td. This method would ideally be implemented in an active filter basing the filter density on the ambient light. For passive filters, roughly estimating the standard brightness level during the activity of the subject would be required to calculate the density of the filter. The visual test can also take into account the eccentricity and the direction of vision and the internal noises can be assessed for different eccentricities and directions. In addition, predetermined maps or response models can be computed for different eccentricities and directions. It is then possible to draw a geographical map of the eye giving for each cornea regions the dominant internal noise for a given luminance and frequency or any other representation of those parameters: region/angle and luminance and frequency and dominant internal noise/related element. Thus, the noise maps indicating the limiting noise source as a function of spatial frequency and/or temporal frequency and luminance intensity can also be measured at different eccentricities or directions. Those maps or even the corresponding models, may have any number of dimensions, 2D, 3D . . . and reference axis, for examples as a function of spatial frequency and temporal frequency and luminance intensity. Other dimensions may be added of substituted such as the eccentricity and the directions, e.g. as a function of eccentricity and luminance intensity. More generally, the noise maps may indicate the limiting noise source as a function of varies variable, e.g., luminance intensity, spatial frequency, temporal frequency, eccentricity, directions, chromaticity . . . same for their corresponding models. Because the cone density drops considerably with eccentricity, the level of photon noise will rise with eccentricity, so the limiting noise source will likely change with eccentricity. Consequently, the critical brightness level, i.e. the lowest luminance intensity at which late neural noise is the dominating internal noise source, will change with eccentricity and direction. As an example, if the critical luminance intensity at which performance to the relevant frequencies is limited by late neural noise is 350 Td at the fovea and 100 Td at 50 degrees of eccentricity, then the density of the filter could block 3.5 times more light at 50 degrees of eccentricity. Thus, the density of the filter can also vary with eccentricity and direction. To reduce retinal illuminance, it is possible to use passive or active filters that take into account the subject's sensitivity to retinal illuminance, i.e. the brightness at which sensitivity is affected, and the visual information that is relevant to the subject: static versus dynamic information, low versus high spatiotemporal frequencies. The density filter may be implemented in an active spectacle that has, for example, electrochromic lenses allowing a variation of the light transmission and also having a luminance sensor. The level of light transmission is preferably controlled by the luminance sensor in order that the luminous flux received by the subject, in specific conditions, is equal or above the minimum luminance level giving an optimal contrast. The prescription thus aims at characterizing the subject's sensitivity for a given activity in a given environment in order to define a density filter that will minimize the impact on the sensitivity of visual information relevant to the subject. The advantages of using information gained from a predetermined map or response model are that limited/optimized visual tests may be used to:Prescribe a density filter personalized to the subject's sensitivity. This technic optimizes visual perception for a given subject.Prescribe a density filter adapted/personalized to the subject's needs or activities, reading, navigation, driving, sports. The density of the filter can also be adjusted to optimize vision according to the subject's needs in order to optimize vision for specific tasks, e.g. low versus high spatiotemporal frequencies, central versus peripheral vision, low versus high luminance intensity. An example of the use of the predetermined map or response model in the case of diagnostic is now described. The diagnostic may concern the search for one or more potential visual diseases or impairments for a given subject or the evaluation of a known disease or impairment in a subject. In both cases, the visual test on the subject is limited/optimized because thanks to knowledge gained form the distribution of the dominant internal noise from the predetermined map or response model, and thus the dominant element affecting sensitivity, the search and evaluation are focused with visual tests that are done on a limited range of luminance or/and frequency or, even, on only one or a few couples of luminance and frequency values. The visual receptors of the eye are rods and cones and they have different functions and repartitions in the cornea. It is possible to estimate the cone absorption rate. The photon noise measurement is caused by the stochastic absorption of photon by photoreceptors. Thus, the measurement of photon noise can be an indicator of the level of photon absorption rate, which depends on photoreceptor density and absorption efficiency. By measuring photon noise using different wavelengths, it is possible to measure the absorption rate of the different photoreceptor types, the three types cones and the rods. Incidentally, this information can be used to determine the chromaticity of the filter in order to minimize its impact on sensitivity in the case of a prescription. The photoreceptor density can also be estimated as a function of eccentricity and direction, for lower and/or upper visual fields. For instance, it is well known that cone density drops with eccentricity and thus the photon noise varies with retinal location. Incidentally, this can be an indicator of adjusting the filtering density as a function of retinal location, e.g. different filter density gradient for lower and upper visual fields, in the case of a prescription. More generally, because measuring photon noise reflects the absorption rate, it is an indicator of a pathological condition. For instance, age-related macular degeneration affects photoreceptors: higher photon noise at the fovea could indicate the beginning of this disease. Furthermore, some other pathological conditions could rather affect cone in the periphery and be related to higher photon noise in the periphery. The visual test that is implemented to check this/those conditions is optimized with a limited range of luminance levels and frequencies because a specific element is assessed, in this instance the photoreceptors and their internal noise that is the photon noise. From the predetermined map or response model one deduces that the photoreceptors can be assessed within a defined limited range of luminance levels and frequencies with the optimized visual test. It is then possible to detect reduced photoreceptor density or efficiency with an optimized test requiring less time and being less cumbersome. Again, the level of photon noise is an indirect measure of the number of photons being absorbed by photoreceptors. If the density of photoreceptors drops or if the photoreceptors become less efficient at absorbing photons, then the measured photon noise will increase. For instance, it has been found that older subjects, ˜70 years, had about four times more photon noise than young subjects, ˜25 years, suggesting that their photoreceptors absorbed about four times less photons. The density of photoreceptors and their efficiency can be assessed with an optimized visual test for measuring the photon noise using only high wavelengths, i.e. red stimulus, and an artificial pupil, the effect of the yellowing of the lens of the eye and myosis being thus neutralized. In these conditions, it has been found that older subjects absorbed about four times less photons than younger ones, suggesting that older subject have less photoreceptors or their photoreceptors are less efficient. Consequently, the measure of photon noise can be useful to detect physiological changes at the photoreceptor level, e.g. healthy aging, and thereby detect developing pathologies, e.g. ARMD, which affects photoreceptors in central vision, or macular edema, which affects also affects photoreceptors in central vision as well as light transmission, or other diseases affecting the peripheral retina. In this context, a predetermined map or response model can also serve as a reference to make comparisons with the measured photon noise from the optimized visual test. Indeed, a pathology that affects photoreceptors will affect the photon absorption rate and thereby the level of photon noise. Age-related macular degeneration, for instance, affects primarily photoreceptors in central vision, whereas retinitis pigmentosa rather affects photoreceptors in the periphery. By measuring the photon noise in central and peripheral vision, and comparing these levels relative to a standard baseline of a healthy population could result in an indicator of a potential disease. A patient having more photon noise in central vision than the baseline would suggest a problem with photoreceptor in central vision, e.g. ARMD. Conversely, a patient with abnormally high photon noise only in the periphery could be an indicator of a retinitis pigmentosa. To efficiently assess the level of photon noise at fixation, contrast sensitivity needs to be measured, preferably using the simplified contrast threshold assessment with and without external noise, in conditions in which photon noise is known to be the main internal noise source, e.g. optimized visual test with only one couple of temporal frequency value, 2 Hz, and luminance intensity, 3 Td tested. To measure photon noise peripherally, e.g. 50 degrees of eccentricity, a similar approach can be used, but with the subject fixating at a fixation point away from the stimulus to detect. Other elements of the visual system than the photoreceptors can be explored and, in particular, post-receptor retinal diseases. Some diseases can affect retinal processing other than at the photoreceptor level, e.g. glaucoma. Such diseases are expected to affect early neural noise. Consequently, measuring a level of early neural noise for the proximal neuronal circuits greater than a standard healthy baseline can be an indicator of some retinal diseases. To efficiently measure the level of early neural noise, contrast sensitivity needs to be measured, preferably using the simplified contrast threshold assessment with and without external noise, in conditions in which early neural noise is known to be the main internal noise source, e.g. optimized visual test with only one couple of temporal frequency value, 15 Hz, and luminance intensity, 100 Td, tested. Still other elements of the visual system can be explored and for example to detect neurological disorders. In this instance, late neural noise could be an indicator of some diseases affecting neural processing, e.g. dementia, autism, schizophrenia, or some psychoactive drugs, e.g., alcohol, cannabis, cocaine, affecting neural processing due to intoxication or long-lasting alterations in brain function. Consequently, measuring higher than normal late neural noise of the distal neuronal circuits could be clinically used to seek for potential neurological disorder. In that instance, an optimized visual test focusing on the late neural noise can be implemented in the same manner as the previous ones for the other elements of the visual system. As we have already seen, simplified contrast threshold assessment for measuring the level of internal noise for a given spatiotemporal frequency and a given luminance level requires only two measurements: contrast threshold in the absence of noise and in high noise to estimate the flat/constant and the rising asymptote parts of the curve and then compute the equivalent input noise thanks to the predetermined sensitivity model modeling the curve. This simplified assessment of contrast threshold allows on its own a substantial gain of time. Using this simplified contrast threshold assessment for measuring the impact of internal noise over a complete range of spatiotemporal frequency and luminance intensity in the whole visual test can thus allow a first reduction of the time it takes. But, with the invention, it is possible to gain much more time with a limitation of the ranges or of the couple(s) of frequencies and luminances that is/are tested thanks to the optimized visual test. For that purpose, a predetermined response model of a visual system that was made at a prior time is used. The element or internal noise that should be assessed is selected. This element or its internal noise is chosen essentially according to the goal of the characterization: the element concerned by the prescription or the diagnostic. The limited/optimized visual test is done with a limited range of variation of frequencies and luminance given by the predetermined response model for that element or internal noise or even limited to one or a few couples of frequency and luminance values. Such a method can be implemented in an apparatus having computation means under the control of a program. The apparatus required to estimate the levels of internal noise is an apparatus enabling to measure contrast sensitivity under various parameters including luminance intensity, spatiotemporal frequency, eccentricity, color range and levels of external noise. To measure contrast sensitivity, such an apparatus would present some stimuli to the subject in the form of visual patterns, e.g. Gabor patch at a given spatiotemporal frequency, eccentricity and luminosity, who would need to make a judgment, e.g. Gabor patch vertically or horizontally oriented. In order to manipulate the frequencies of the patterns, a display may be used with the apparatus, e.g. a computer screen. That display may be a static or a dynamic display. Furthermore, the luminance intensity needs to be quantified in retinal illumination, e.g. Trolands, which depends on the display luminance intensity and the pupil size. Ideally, the apparatus could automatically measure the pupil size to efficiently control the retinal illumination. Alternatively, an artificial pupil with a known fixed diameter, e.g. 2 mm, smaller than the subject's pupil can be put in front of the subject's pupil. Another possibility is that the pupil size is manually measured or automatically measured and the information is used to calculate the retinal illumination. The computer screen may be an active spectacle capable of displaying visual patterns and added variable noise.

11857255

DETAILED DESCRIPTION Representative, non-limiting examples of the present disclosure will now be described in further detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the present disclosure. Furthermore, each of the additional features and teachings disclosed below may be utilized separately or in conjunction with other features and teachings to provide improved ophthalmic apparatuses, as well as methods for using and manufacturing the same. Moreover, combinations of features and steps disclosed in the following detailed description may not be necessary to practice the present disclosure in the broadest sense, and are instead taught merely to particularly describe representative examples of the present disclosure. Furthermore, various features of the above-described and below-described representative examples, as well as the various independent and dependent claims, may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings. All features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter, independent of the compositions of the features in the embodiments and/or the claims. In addition, all value ranges or indications of groups of entities are intended to disclose every possible intermediate value or intermediate entity for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter. Some of the features characteristic to below-described embodiments will herein be listed. It should be noted that the respective technical elements are independent of one another, and are useful solely or in combinations. The combinations thereof are not limited to those described in the claims as originally filed. A first ophthalmic apparatus disclosed in the present may comprise: an image capturing unit configured to capture a target part of a subject eye; a processor; and a memory storing computer-readable instructions therein. The computer-readable instructions, when executed by the processor, may cause the ophthalmic apparatus to execute: acquiring a first image of the target part captured at a first timing by the image capturing unit and a second image of the target part captured at a second timing different from the first timing; and combining the first image with the second image to generate one combined image of the target part. With the above-described ophthalmic apparatus, by combining the first and second images in each of which the target part of the subject eye is captured to generate one combined image, a portion in the first image where the target part is not captured can be supplemented by a corresponding portion in the second image, for example. Due to this, the number of times the target part of the subject eye needs to be captured to acquire a desired image can be reduced, and burden on an examinee can be reduced. A second ophthalmic apparatus disclosed herein may be configured to measure a target part of a subject eye. The ophthalmic apparatus may comprise: an image capturing unit configured to capture the target part; a processor; a memory storing computer-readable instructions therein; and an informing unit. The computer-readable instructions, when executed by the processor, may cause the ophthalmic apparatus to execute: acquiring an image of the target part captured by the image capturing unit; and identifying a non-detected region in the image of the target part, the non-detected region being a region in which the target part is not detected. The informing unit may be configured to inform presence of the identified non-detected region. In the above-described ophthalmic apparatus, by the informing unit informing the presence of the non-detected region in the captured image, an examiner can identify where the non-detected region is positioned. Due to this, for example, the examiner can recapture an entirety of the target part so that the non-detected region is included therein, by which the number of times the target part of the subject eye needs to be captured to acquire the desirable image can be reduced, and burden on the examinee can be reduced. The ophthalmic apparatus disclosed herein may further comprise a display unit configured to display images of the target part including the combined image of the target part. According to such a configuration, the combined image of the target part can be visually identified. In the ophthalmic apparatus disclosed herein, the first image may be an image that is captured when an eyelid uncovers a first region of the target part. The second image may be an image that is captured when the eyelid uncovers a second region of the target part. The second region may be different from the first region. According to such a configuration, since a degree by which the eyelid uncovers the subject eye when the first image is captured (a state where the eyelid uncovers the first region) is different from a degree by which the eyelid uncovers the subject eye when the second image is captured (a state where the eyelid uncovers the second region), a captured region of the target part in the first image is different from that in the second image. By combining these images, an image including the target part in a broader area can be acquired. In the ophthalmic apparatus disclosed herein, in the combining, the first image and the second image may be combined by matching positions of a common portion captured respectively in the first image and the second. According to such a configuration, by matching the positions of the common portion between the first image and the second image, displacement caused upon combining the first and second images can be suppressed. In the ophthalmic apparatus disclosed herein, the computer-readable instructions, when executed by the processor, may further cause the ophthalmic apparatus to execute identifying a non-detected region in the first image, the non-detected region being a region in which the target part is not detected. In the combining, a portion of the second image corresponding to the non-detected region of the first image may be combined with a portion of the first image where the target part is detected. According to such a configuration, by combining the portion of the second image corresponding to the non-detected region of the first image with the portion of the first image where the target part is detected, a portion of the first image where the target part is not detected can be replaced with the corresponding portion of the second image. Due to this, an image including the target region in a broader area can be acquired. The ophthalmic apparatus disclosed herein may further comprise an informing unit configured to inform presence of the non-detected region when an image captured by the image capturing unit includes the non-detected region. According to such a configuration, when the target part of the subject eye is captured by the image capturing unit and the captured image includes the non-detected region, the informing unit informs the presence of the non-detected region, by which the examiner can identify where the non-detected region, which needs to be recaptured, is positioned. Due to this, for example, the examiner can recapture an image such that the image includes the non-detected region, by which an image more suitable as an image to be combined can be acquired. In the ophthalmic apparatus disclosed herein, the informing unit may be further configured to: instruct to open an eyelid to uncover an upper part of the subject eye when the non-detected region is located in the upper part of the subject eye; instruct to open the eyelid to uncover a lower part of the subject eye when the non-detected region is located in the lower part of the subject eye; and instruct to open the eyelid to uncover the upper and lower parts of the subject eye when the non-detected regions are located in the upper and lower parts of the subject eye. According to such a configuration, the informing unit can instruct the examiner so that a more suitable image can be acquired depending on a position of the non-detected region. EMBODIMENT Hereinbelow, an ophthalmic apparatus1according to an embodiment will be described. The ophthalmic apparatus1is configured to capture tomographic images of an anterior eye part of a subject eye E by using an Optical Coherence Tomography (OCT). As shown inFIG.1, the ophthalmic apparatus1includes a light source10, an interference optical system14configured to cause reflected light reflected from the subject eye E and reference light to interfere with each other, and a K-clock generator50configured to generate K-clock signals. The light source10is a wavelength-sweeping light source, and is configured to change a waveform of the light emitted therefrom in a predetermined cycle. When the wavelength of the light emitted from the light source10changes, a reflected position of reflected light that interferes with the reference light, among reflected light from respective parts of the subject eye E in a depth direction, changes in the depth direction of the subject eye E in accordance with the wavelength of the emitted light. Due to this, it is possible to identify positions of the respective parts (such as a cornea and a crystalline lens) inside the subject eye E by measuring the interference light while changing the wavelength of the emitted light. The light outputted from the light source10is inputted to a fiber coupler12through an optical fiber. The light inputted to the fiber coupler12is split in the fiber coupler12, and the split light is outputted to a fiber coupler16and the K-clock generator50through optical fibers. The K-clock generator50will be described later. The interference optical system14includes a measurement optical system configured to irradiate inside of the subject eye E with light from the light source10and generate reflected light therefrom, a reference optical system configured to generate reference light from the light of the light source10, and a balance detector40configured to detect interference light that is a combination of the reflected light guided by the measurement optical system and the reference light guided by the reference optical system. The measurement optical system is constituted of the fiber coupler16, a circulator18, and a scanning-alignment optical system20. The light outputted from the light source10and inputted to the fiber coupler16through the fiber coupler12is split in the fiber coupler16into measurement light and reference light, and these light are outputted therefrom. The measurement light outputted from the fiber coupler16is inputted to the circulator18through an optical fiber. The measurement light inputted to the circulator18is outputted to the scanning-alignment optical system20. The scanning-alignment optical system20is configured to irradiate the subject eye E with the measurement light outputted from the circulator18and to output reflected light from the subject eye E to the circulator18. The reflected light inputted to the circulator18is inputted to one of inputs of a fiber coupler38. The scanning-alignment optical system20will be described later in detail. The reference optical system is constituted of the fiber coupler16, a circulator22, and a reference unit24. The reference light outputted from the fiber coupler16is inputted to the circulator22through an optical fiber. The reference light inputted to the circulator22is outputted to the reference unit24. The reference unit24is constituted of collimator lenses26,28and a reference mirror30. The reference light outputted to the reference unit24is reflected by the reference mirror30through the collimator lenses26,28, and is outputted from the reference unit24through the collimator lenses26,28again. The reference light outputted from the reference unit24is outputted to the circulator22. The collimator lens28and the reference mirror30are each configured to be moved forward and rearward relative to the collimator lens26by a second driver54(seeFIG.3). When the second driver54moves the collimator lens28and the reference mirror30, an optical path length of the reference optical system changes. Due to this, the optical path length of the reference optical system can be adjusted to be substantially equal to an optical path length of the measurement optical system. The reference light inputted to the circulator22is inputted to another input of the fiber coupler38through a polarized wave controller36. The polarized wave controller36is an element configured to control polarization of the reference light to be inputted to the fiber coupler38. As the polarized wave controller36, a configuration such as a paddle type or an inline type used in known ophthalmic apparatuses can be used, thus a detailed description thereof will be omitted. The fiber coupler38is configured to combine the reflected light from the subject eye E and the reference light that were inputted thereto to generate interference light. The fiber coupler38is further configured to split the generated interference light into two interference light having phases that differ by 180 degrees from each other, and input them to the balance detector40. The balance detector40is configured to execute a process for differential amplification and a process for reducing noise on the two interference light having the phases that differ by 180 degrees, which were inputted from the fiber coupler38, to convert them into electric signals (interference signals). The balance detector40is configured to output the interference signals to a processor60. Here, a configuration of the scanning-alignment optical system20will be described with reference toFIG.2. The scanning-alignment optical system20includes a scanning optical system, an anterior-eye-part image capturing system, a fixation target optical system, and an alignment optical system. As shown inFIG.2, the scanning optical system includes a collimator lens102, a Galvano scanner104, a hot mirror106, and an object lens108. The measurement light outputted from the circulator18(seeFIG.1) is emitted to the Galvano scanner104through the collimator lens102. The Galvano scanner104is configured to be tilted by a first driver52(seeFIG.3), and a position irradiated with the measurement light in the subject eye E is scanned by the first driver52tilting the Galvano scanner104. The hot mirror106is irradiated with the measurement light emitted from the Galvano scanner104and the measurement light is reflected there at an angle of 90 degrees. The measurement light with which the hot mirror106was irradiated is provided to the subject eye E through the object lens108. Reflected light from the subject eye E is inputted to the circulator18after passing through the object lens108, the hot mirror106, the Galvano scanner104, and the collimator lens102along a reversed path from the above. The anterior-eye-part image capturing system includes two illuminating light sources110, the object lens108, the hot mirror106, a cold mirror112, an imaging lens114, a CCD camera116, and an optical controller118. The two illuminating light sources110are configured to irradiate a front side of the subject eye E with illumination light in a visible range. Reflected light from the subject eye E travels through the object lens108, the hot mirror106, the cold mirror112and the imaging lens114and is inputted to the CCD camera116. Due to this, a front image of the subject eye E is captured. Data of the captured image is subjected to image processing by the optical controller118and is displayed on a touch panel56. The fixation target optical system includes a fixation target light source120, cold mirrors122,124, a relay lens126, a half mirror128, the cold mirror112, the hot mirror106, and the object lens108. Light from the fixation target light source120travels through the cold mirrors122,124, the relay lens126and the half mirror128, and is reflected on the cold mirror112. The light reflected on the cold mirror112travels through the hot mirror106and the object lens108, and the subject eye E is irradiated with the light. By causing an examinee to fix his/her vision at the light from the fixation target light source120, an eyeball (that is, the subject eye E) can be held still as much as possible. The alignment optical system is constituted of an XY-direction position detection system and a Z-direction position detection system. The XY-direction position detection system is used to detect positions of the subject eye E (to be more precise, a corneal apex thereof) in XY directions (that is, positional displacements thereof in up-down and right-left directions relative to the ophthalmic apparatus1). The Z-direction position detection system is used to detect a position of the corneal apex of the subject eye E in a front-rear direction (a Z direction). The XY-direction position detection system includes an XY-position detection light source130, the cold mirror124, the relay lens126, the half mirror128, the cold mirror112, the hot mirror106, the object lens108, an imaging lens132, and a position sensor134. The XY-position detection light source130is configured to emit alignment light for position detection. The alignment light emitted from the XY-position detection light source130is reflected on the cold mirror124, travels through the relay lens126and the half mirror128, and is reflected on the cold mirror112. The light reflected on the cold mirror112travels through the hot mirror106and the object lens108, and the anterior eye part (cornea) of the subject eye E is irradiated with the light. Since a corneal surface of the subject eye E is spherical, the alignment light is reflected on the corneal surface so as to form a bright spot image on an inner side with respect to the corneal apex of the subject eye E. The reflected light from this corneal surface enters the object lens108and is reflected on the cold mirror112through the hot mirror106. The reflected light reflected on the cold mirror112is reflected on the half mirror128and is inputted to the position sensor134through the imaging lens132. A position of the corneal apex (that is, its position in X and Y directions) is detected by the position sensor134detecting a position of the bright spot. The detection signal of the position sensor134is inputted to the processor60through the optical controller118. In this case, alignment is set between the position sensor134and the anterior-eye-part image capturing system, and a predetermined (regular) image acquisition position for the corneal apex (a position thereof to be tracked upon acquiring tomographic images) is set. The regular image acquisition position for the corneal apex is, for example, a point that matches a center position of an image captured by the CCD camera116. The processor60is configured to calculate positional displacement amounts of the detected corneal apex (bright point) in the X and Y directions relative to the regular image acquisition position based on the detection of the position sensor134. The Z-direction position detection system includes a Z-position detection light source140, an imaging lens142, and a line sensor144. The Z-position detection light source140is configured to irradiate the subject eye E with light for detection (slit light or spot light) from an oblique direction with respect to the subject eye E. Reflected light in the oblique direction from the cornea of the subject eye E enters the line sensor144through the imaging lens142. At this occasion, an incident position of the reflected light entering the line sensor144varies depending on the position of the subject eye E in the front-rear direction (Z-direction) relative to the ophthalmic apparatus1. Due to this, the position of the subject eye E in the Z direction relative to the ophthalmic apparatus1is detected by detecting the incident position of the reflected light. The detection signal of the line sensor144is inputted to the processor60. The K-clock generator50(seeFIG.1) is configured to optically generate sample clock (K-clock) signals from the light of the light source10to sample the interference signals at a regular interval frequency (frequency interval that is equalized with respect to light frequency). Further, the generated K-clock signals are outputted toward the processor60. Due to this, the processor60samples the interference signals based on the K-clock signals, by which distortion in the interference signals can be suppressed and deterioration in resolution can be prevented. In the present embodiment, the interference signals that were sampled at timings defined by the K-clock signals are inputted to the processor60, however, no limitation is placed to this configuration. For example, the processor60may execute a process to scale data sampled at a predetermined time interval by using a function indicating a frequency with respect to a preset sweep time, or a sweep profile that is acquired simultaneously therewith. Next, a configuration of a control system of the ophthalmic apparatus1according to the present embodiment will be described. As shown inFIG.3, the ophthalmic apparatus1is controlled by the processor60. The processor60is constituted of a microcomputer (microprocessor) constituted of a CPU, a ROM, a RAM, and the like. The processor60is connected with the light source10, the first driver52, the second driver54, the illuminating light sources110, the fixation target light source120, the XY-position detection light source130, the Z-position detection light source140, the optical controller118, the line sensor144, the balance detector40, the K-clock generator50, and the touch panel56. The processor60is configured to control on/off of the light source10and to drive the Galvano scanner104and the reference unit24by controlling the first driver52and the second driver54. Further, the interference signals corresponding to intensities of the interference light detected by the balance detector40and the K-clock signals generated by the K-clock generator50are inputted to the processor60. The processor60is configured to sample the interference signals from the balance detector40based on the K-clock signals. Further, the processor60executes Fourier transform on the sampled interference signals to identify positions of respective parts (such as the cornea, an anterior chamber, and a crystalline lens) of the subject eye E. Data and calculation results inputted to the processor60are stored in a memory (not shown). Further, the processor60is configured to control on/off of the illuminating light sources110, the fixation target light source120, and the XY-position detection light source130. The front image of the subject eye E captured by the CCD camera116and processed by the optical controller118and the position of the corneal apex (bright point) detected by the position sensor134via the optical controller118are inputted to the processor60. The processor60is configured to calculate the displacement amounts of the corneal apex (bright point) in the XY directions based on the front image of the subject eye E and the position of the corneal apex (bright point) that were inputted. The detection signal of the line sensor144is inputted to the processor60, and the processor60is configured to calculate the displacement amount of the subject eye E in the Z direction relative to the ophthalmic apparatus1. Based on the positional displacement amounts of the corneal apex (bright point) in the X and Y directions detected by the XY-direction position detection system and the positional displacement amount of the subject eye E in the Z direction detected by the Z-direction position detection system, the processor60controls a main driver (not shown) such that the aforementioned positional displacement amounts all become 0 and moves a main body of the ophthalmic apparatus1relative to a stage (not shown). Further, the processor60controls the touch panel56. The touch panel56is a display unit for providing the examiner with a variety of information related to a measurement result and an analysis result of the subject eye E, and is also a user interface configured to receive instructions and information from the examiner. For example, the touch panel56can display an image of the anterior eye part, tomographic images, the analysis result, and an instruction on presence of a non-detected region72to the examiner (to be described later) generated by the processor60. Further, various settings for the ophthalmic apparatus1can be imputed to the touch panel56. Although the ophthalmic apparatus1of the present embodiment includes the touch panel56, the disclosure herein is not limited to such a configuration. The ophthalmic apparatus may have a configuration which enables display and input of the aforementioned information, and may include a monitor and an input device (e.g., a mouse and a keyboard). Processes of acquiring an image of a scleral spur SS of the subject eye E will be explained with reference toFIGS.4to11. For example, when a state of an angle recess is evaluated by using tomographic images, the tomographic images need to be captured so that the images include the angle recess. However, when an eyelid insufficiently uncovers the subject eye E, the angle recess on an upper side or on a lower side of the subject eye E may not be captured due to being covered by the eyelid. The ophthalmic apparatus1according to the present embodiment is configured to acquire an image including an entirety of the angle recess of the subject eye E in its circumferential direction. Hereafter, it is determined that an image includes the angle recess when the image includes the scleral spur SS positioned at an anterior chamber angle part. As such, processes of acquiring an image which includes an entirety of the scleral spur SS of the subject eye E in its circumferential direction will be described. Firstly, as shown inFIG.4, the processor60acquires tomographic images of the anterior eye part of the subject eye E (S12). The process of acquiring tomographic images of the anterior eye part of the subject eye E is executed according to the following procedure. Firstly, when the examiner inputs an instruction to start an examination on the touch panel56, the processor60executes alignment between the subject eye E and the ophthalmic apparatus1. The alignment is executed based on the displacement amounts in the XY directions and the Z direction detected by the alignment optical system. Specifically, the processor60moves the main body of the ophthalmic apparatus1relative to the stage (not shown) so that the positional displacement amounts of the corneal apex (bright point) in the X and Y directions detected by the XY-direction position detection system and the positional displacement amount of the subject eye E in the Z direction detected by the Z-direction position detection system all become 0. When the alignment is completed, the processor60captures tomographic images of the anterior eye part of the subject eye E. In this embodiment, the measurement of the anterior eye part of the subject eye E in step S12is executed according to a radial scanning scheme. Due to this, the tomographic images of the anterior eye part are acquired over an entire region thereof. That is, as shown inFIG.5, the tomographic images are captured with B-scan directions set in radial directions from the corneal apex of the subject eye E and a C-scan direction set in a circumferential direction thereof. In this embodiment, the tomographic images are captured in 128 directions radially (specifically, in 128 directions at regular intervals in the circumferential direction) according to the radial scanning scheme. The processor60records data of the acquired (captured) tomographic images in the memory. A method of capturing tomographic images of the anterior eye part is not limited to the radial scanning scheme. Any method may be adopted so long as it is able to acquire tomographic images of the anterior eye part over an entire region thereof, and for example, the images may be captured according to a raster scanning scheme. That is, as shown inFIG.6, the tomographic images may be captured with the B-scan direction in a horizontal direction and the C-scan direction set in a vertical direction relative to the subject eye E. In step S12, when the tomographic images of the anterior eye part of the subject eye E are acquired, the processor60detects the scleral spur SS in each of the tomographic images (S14). The scleral spur SS in each of the tomographic images can be detected by using a well-known method, thus the method is not particularly limited. For example, the scleral spur SS in each of the tomographic images may be detected by the examiner inputting position(s) of the scleral spur SS to the two-dimensional tomographic image displayed on the touch panel56, or may be detected by the processor60executing a well-known image processing program (for example, program for detecting a posterior surface of a cornea and an anterior surface of an iris and determining a boundary therebetween). As shown inFIG.7A, when the eyelid sufficiently uncovers the subject eye E upon capturing, the scleral spur SS is captured at two points in all the tomographic images. In this case, the scleral spur SS is detected at two points in all the tomographic images. On the other hand, as shown inFIG.8A, when the eyelid does not sufficiently uncover the subject eye E upon capturing images, the scleral spur SS at an upper part and a lower part of the subject eye E (or the scleral spur SS at one of the upper part or the lower part of the subject eye E) may not be captured. In this case, the scleral spur SS cannot be detected in image(s) including the upper and lower parts (or one of the upper part or the lower part) of the subject eye E covered by the eyelid among a plurality of tomographic images. Next, the processor60overlaps region(s)70where the scleral spur SS has been detected and region(s)72where the scleral spur SS has not been detected on the image of the anterior eye part of the subject eye E and displays the resulting image on the touch panel56(S16). Specifically, the processor60overlaps circumferential region(s)70where the scleral spur SS has been detected (hereinbelow simply referred to as “detected region(s)70”) and circumferential region(s)72where the scleral spur SS has not been detected (hereinbelow simply referred to as “non-detected region(s)72”) on the image of the anterior eye part and display the resulting image. As shown inFIG.7B, when the scleral spur SS has been detected in all the tomographic images in step S14, the detected region70is displayed over its entire circumference, and the non-detected region72is not displayed. At this occasion, the detected region70may be displayed by connecting the scleral spur SS detected in adjacent tomographic images by line segments, or may be displayed as a reference ellipse including circle (hereinafter referred to as “reference circle”) calculated based on positions of the detected scleral spur SS. Since a method of calculating the above reference circle is identical with a well-known calculation method described in Japanese Patent No. 6367534, for example, thus the detailed explanation thereof will be omitted. Hereinbelow, this method of calculating the reference circle may be referred to as “SS entire circumference fitting”. On the other hand, as shown inFIG.8B, when the plurality of tomographic images includes image(s) in which the scleral spur SS has not been detected in step S14, portions of the circumference corresponding to positions where the scleral spur SS has been detected are displayed as the detected regions70, while reminder portions of the circumference corresponding to positions where the scleral spur SS has not been detected are displayed as the non-detected regions72. The detected regions70and the non-detected regions72may be identified by using, for example, the SS entire circumference fitting. In other words, the processor60calculates the reference circle by the SS entire circumference fitting by using a plurality of positions of the scleral spur SS, displays areas of the reference circle corresponding to positions where the scleral spur SS has been detected as the detected regions70, and displays areas of the reference circle corresponding to positions where the scleral spur SS has not been detected as the non-detected regions72. For example, as shown inFIG.8B, when the eyelid sufficiently uncovers neither the upper part nor the lower part of the subject eye E, regions on left and right sides excluding the upper and lower parts become the detected regions70, and the upper and lower parts become the non-detected regions72. In the present embodiment, the detected regions70are displayed in solid lines, and the non-detected regions72are displayed in broken lines. As such, the detected regions70and the non-detected regions72are displayed in different manners, by which the examiner can easily distinguish the detected regions70and the non-detected regions72. Tomographic images of cross sections of the subject eye E including a corneal apex and being parallel to a Y-axis and Z-axis (seeFIGS.1and2) are displayed on the touch panel56as well as the image of the anterior eye part (specifically, the image of the anterior eye part on which the detected region(s)70and the non-detected region(s)72of the scleral spur SS are overlapped). The processor60overlaps line segments74which indicate positions of the scleral spur SS on the tomographic images displayed on the touch panel56. Specifically, as shown inFIG.7B, when the upper and lower parts of the subject eye E are the detected region70, the line segments74are displayed in the tomographic images at positions corresponding to the detected region70displayed in the image of the anterior eye part. As such, in the tomographic images, the scleral spur SS is positioned on the line segments74. On the other hand, as shown inFIG.8B, when the upper and lower parts of the subject eye E are the non-detected regions72(or when one of the upper or lower part of the subject eye E is the non-detected region72), the line segments74are displayed at positions corresponding to positions where the non-detected regions72of the image of the anterior eye part are displayed (i.e., positions on the reference circle). Thus, the line segments74are displayed at positions where the subject eye E has not been captured in the tomographic images. Next, the processor60determines whether or not the non-detected region72is included in the image of the anterior eye part displayed in step S16(S18). When the non-detected region72is not included in the image of the anterior eye part (NO in step S18), it can be determined that the tomographic images of the scleral sur SS are acquired over its entire circumference (seeFIG.7B). Due to this, the processor60terminates the processes of acquiring the image of the scleral spur SS of the subject eye E. On the other hand, when the non-detected region72is included in the image of the anterior eye part (YES in step S18), it can be determined that there still is a portion in which the tomographic images of the scleral spur SS have not been acquired in its circumferential direction. In this case, as shown inFIG.8B, the processor60displays marks76informing the presence of the non-detected regions72on the touch panel56(S20). For example, inFIG.8B, the non-detected regions72are respectively present at the upper and lower parts of the subject eye E. Due to this, the processor60displays the marks76each indicating the non-detected region72at the upper part and at the lower part. Due to this, the examiner can be informed which regions of the subject eye E are not captured, and be urged to recapture the non-detected regions72. Thus, the examiner can accurately identify the regions of the subject eye E which have not been captured, by which the number of times the subject eye E needs to be recaptured can be reduced. According to the marks76as informed, the examiner recaptures the tomographic images of the anterior eye part of the subject eye E so that the non-detected regions72can be captured. For example, when the mark76which indicates the upper part of the subject eye E is displayed, the examiner captures the subject eye E by causing the eyelid to uncover the upper part of the subject eye E. When the mark76which indicates the upper part of the subject eye E and the mark76which indicates the lower part of the subject eye E are both displayed, the examiner captures the subject eye E by causing the eyelid to uncover the upper and lower parts of the subject eye E, or captures the subject eye E by causing the eyelid to uncover one of the upper or lower parts of the subject eye E. In the present embodiment, the marks76which indicate the non-detected regions72are displayed, but a configuration thereof is not limited to such a configuration. The examiner may be informed of the presence of the non-detected regions72, and the non-detected regions72may be displayed in a manner which can more easily draw attentions than the detected regions70. For example, the detected regions70and the non-detected regions72may be displayed in different colors (for example, the detected regions70may be displayed in green, and the non-detected regions72may be displayed in red) or only the non-detected regions72may blink. Further, instead of displaying the marks76which indicate the non-detected regions72(or in addition to displaying the marks76), the presence of the non-detected regions72may be informed by a voice announcement, for example, “please recapture upper and lower parts”. Next, the processor60determines whether or not an instruction for starting an examination to acquire the tomographic images of the subject eye E has been inputted (S22). In other words, the processor60determines whether or not the instruction to recapture the tomographic images of the subject eye E has been inputted by the examiner. When the instruction for starting the examination has not been inputted (NO in step S22), the processor60waits until the instruction for starting the examination is inputted. On the other hand, when the instruction for starting the examination has been inputted (YES in step S22), the processor60acquires the tomographic images of the anterior eye part of the subject eye E (S24), and detects the scleral spur SS in each of the acquired tomographic images (S26). Since the processes of step S24and step S26are the same as the above-described step S12and step S14, respectively, the detailed explanations thereof will be omitted. Next, the processor60executes matching of the image of the anterior eye part acquired from the tomographic images acquired in step S12(hereinafter referred to as a first captured image) and the image of the anterior eye part acquired from the tomographic images acquired in step S24(hereinafter referred to as a second captured images) (S28). The first captured image and the second captured image differ in their captured ranges of the subject eye E. For example, a central part excluding the upper and lower parts of the subject eye E is captured in the first captured image, while the lower part and the central part excluding the upper part of the subject eye E are captured in the second captured image as shown inFIG.9. The processor60matches positions of the first captured image and the second captured image by using a common portion between a captured range of the first captured image and a captured range of the second captured image. Due to this, in a combining process which will be described later, displacement between the first captured image and the second captured image can be prevented from occurring. A method of the matching is not particularly limited, and a well-known method thereof can be used. For example, the matching can be executed by using the following method. First, the processor60generates a two-dimensional tomographic image for each scan angle for each of the first captured image and the second captured image. A corneal apex is to be included in each generated two-dimensional tomographic image. Next, the processor60executes pattern matching of a plurality of two-dimensional tomographic images acquired from the first captured image and a plurality of two-dimensional images acquired from the second captured image, and determines an angle difference where a gap therebetween becomes minimum. Specifically, in a state where positions of the corneal apex in the first captured image and the corneal apex in the second captured image are matched, the processor60calculates respective luminance differences between each two-dimensional tomographic image acquired from the plurality of two-dimensional tomographic images and a corresponding one of the plurality of two-dimensional tomographic images acquired from the second captured image while changing an angle where datum line of the first captured image (a straight line which passes the corneal apex) and a datum line of the second captured image (a straight line which passes the corneal apex), and acquires a sum of these calculated luminance differences. When the luminance differences are calculated, the calculation is carried out by comparing respective luminance difference information of the anterior surface of the cornea of two-dimensional tomographic images corresponding to each other. Then, an angle difference where the sum of the luminance differences becomes minimum (an angle at which the datum line of the first captured image and the datum line of the second captured image meet) is determined, and this angle difference is determined as an angular displacement between the first captured image and the second captured image (displacement of a scan angle between the two captured images). Then, the positions of the first captured image and the second captured image are matched by giving consideration to the determined angular displacement (displacement of a scan angle). The matching may be executed by using the SS entire circumference fitting. Specifically, the processor60at first calculates the reference circle by using the SS entire circumference fitting for each of the first captured image and the second captured image. Next, the processor60calculates gaps between the reference circle and respective positions of the detected scleral spur SS for the first captured image, and sets an angle where a sum of the gaps become minimum as a displacement angle of the first captured image. Further, the processor60calculates gaps between the reference circle and respective positions of the detected scleral spur SS for the second captured image, and sets an angle where a sum of the gaps become minimum as a displacement angle of the second captured image. Then, the positions of the first captured image and the second captured image in XY directions are matched so that centers of the reference circles of the two images match, and the positions of the first captured image and the second captured image are matched in an angle direction by displacing the first captured image by the displacement angle of the first captured image and displacing the second captured image by the displacement angle of the second captured image. The matching may be executed by using the image of the anterior eye part. Specifically, the processor60at first respectively identifies an iris of the subject eye E for the image of the anterior eye part corresponding to the first captured image and the image of the anterior eye part corresponding to the second captured image. Next, the processor60executes the matching so that patterns of the identified respective irises match, and matches the positions of the first captured image and the second captured image. For example, the processor60extracts the characteristic pattern of the iris identified from the first captured image and extracts the characteristic pattern of the iris identified from the second captured image. Then, respective micromortion angles and amounts of movement of the first captured image and the second captured image are identified so that the characteristic pattern extracted from the first captured image and the characteristic pattern extracted from the second captured image are matched, and the two captured images are matched in position. The matching may be executed by using measured data of the subject eye E (e.g., a measurement parameter which characterizes the subject eye E). An angle opening distance (AOD) may be employed as the measurement data, for example, but a type of measurement data to be employed is not particularly limited. For example, at first, the processor60acquires AOD data acquired from the first captured image and AOD data acquired from the second captured image. The pair of AOD data match in parts where the captured ranges are in common. Due to this, the processor60offsets one of the pair of AOD data (or both) so that the parts where the pair of AOD data match overlap. Due to this, the first captured image and the second captured image are matched in position. Next, the processor60replaces the non-detected region(s)72in the first captured image with corresponding region(s) in the second captured image, and combines the two captured images (S30). In other words, the processor60cuts out the region(s) corresponding to the non-detected region(s)72in the first captured image from the second captured image, and combine the cut-out region(s) with the detected region70of the first captured image. For example, as shown inFIG.8B, in supposing that the non-detected regions72of the first captured image are at the upper and lower parts of the subject eye E, and the eyelid uncovers the lower part of the subject eye E but does not uncover the upper part thereof in the second capturing. In other words, in supposing that the scleral spur SS at the lower part of the subject eye E is captured in the second captured image, while the scleral spur SS at the upper part of the subject eye E is not captured. In this case, the processor60cuts out both the region corresponding to the non-detected region72at the upper part of the first captured image and the region corresponding to the non-detected region72at the lower part of the non-detected region72from the second captured image, and combines the two regions with the detected regions70of the first captured image. Then, an image in which the scleral spur SS at the lower part of the subject eye E is captured together with the scleral spur SS at the right and left parts of the subject eye E (that is, an image in which only the scleral spur SS at the upper portion of the subject eye E is not captured) is generated. The processor60may cut out only portion(s) which has (have) been detected in the second captured image and combine the portion(s) with the first captured image. Specifically, the processor60identifies the detected region(s)70and the non-detected region(s)72in the second captured image. Next, the processor60cuts out only region(s) corresponding to the non-detected region(s)72in the first captured image among the detected region(s)70in the second captured image, and combines the cut-out region(s) with the first captured image. In other words, in the above example, the processor60cuts out only a region corresponding to the non-detected region72at the lower part of the first captured image from the second captured image. Then the processor60combines the region cut out from the second captured image (that is, the region corresponding to the non-detected region72at the lower part of the first captured image) with the detected region70and the upper non-detected region72of the first captured image. Next, the processor60displays the combined image generated in step S30on the touch panel56, and overlaps the detected region(s)70and the non-detected region(s)72of the combined image with the combined image, and displays the resulting image (S32). Then, the processor60determines whether or not the combined image generated in step S30includes the non-detected region(s)72(S34). When the combined image includes the non-detected region(s)72(YES in step S34), the processor60returns to step S20and repeats the processes of step S20to step S34. On the other hand, when combined image does not include the non-detected region72(NO in step S34), the processor60terminates the process of acquiring the image of the scleral spur SS of the subject eye E. For example, when the first captured image has the two non-detected regions72at the upper and lower parts of the subject eye E as shown inFIG.8Band the eyelid uncovers the lower part of the subject eye E but does not uncover the upper part thereof in the second capturing as shown inFIG.9, the image generated in step S30includes the non-detected region72at the upper part of the subject eye E. In this case, the processor60returns to step S20and causes the touch panel56to display the mark76instructing the presence of the non-detected region72at the upper part of the subject eye E as shown inFIG.10. Due to this, the examiner can be informed that the scleral spur SS at the upper part of the subject eye E is not captured. And, the examiner recaptures the subject eye E in a state where the eyelid uncovers the upper part of the subject eye E according to the instruction. Then, as shown inFIG.11, the scleral spur SS at the upper part of the subject eye E is captured. After this, the processor60executes the processes of step S22to step S34, cuts out a region corresponding to the non-detected region72at the upper part of the subject eye E from a third captured image, and combines the region which has been cut out from the third captured image and the combined image generated in the previous step S30. Then, an image in which the scleral spur SS is captured over its entire circumference is generated as shown inFIG.7A. As such, even though an image in which the scleral spur SS is captured over its entire circumference cannot be captured at the first capturing, an image in which a desirable area is captured can be generated by combining a plurality of images. When the ophthalmic apparatus1of the present embodiment is used, the image in which the scleral spur SS is captured over its entire circumference can be generated by combining images captured for a plurality of times. Due to this, there is no need capturing the subject eye E many times until a desirable image is captured, thus the number of capturing needed to capture the desirable image can be reduced. Further, since the examiner can be informed of the presence of the non-detected region(s)72, the examiner can appropriately identify region(s) remained to be recaptured. Due to this, the number of capturing needed to capture the desirable image can be reduced. Since the number of capturing can be reduced as such, burden on the examinee can be reduced. Although the image in which the scleral spur SS is captured over its entire circumference is acquired (generated) in the present embodiment, a configuration thereof is not limited to such a configuration. A target part to be captured is not limited to the scleral spur SS, but it may be any part or region in the subject eye E. For example, the target part may be an anterior chamber angle portion including the scleral spur SS, or may be an anterior eye part including a cornea. Further, the target part may be a region including tissues of the subject eye E excluding the anterior eye part. Further, the combined image may not be generated to include the entire target part such as the scleral spur SS, and the entire target part may not be included as long as the desired area is included. For example, the combined image may not be generated to include an entire target part in its circumferential direction (i.e., 360°), and it may be generated to include the desired area thereof in its circumferential direction (e.g., 270° or greater). Notes for the ophthalmic apparatus1disclosed in the embodiment will be described. The interference optical system14and the K-clock generator50are examples of “image capturing unit”, the touch panel56is an example of “display unit” and “informing unit”, and the processor60is an example of “processor”. Specific examples of the disclosure herein have been described in detail, however, these are mere exemplary indications and thus do not limit the scope of the claims. The art described in the claims includes modifications and variations of the specific examples presented above. Technical features described in the description and the drawings may technically be useful alone or in various combinations, and are not limited to the combinations as originally claimed.

11857256

DETAILED DESCRIPTION OF EMBODIMENTS Example embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” “having” and variations thereof herein, is meant to encompass the items listed thereafter, equivalents thereof, and additional items, as well as alternate embodiments consisting of the items listed thereafter exclusively. In one example embodiment herein, the systems, apparatuses, methods, computer-readable mediums, and computer programs described herein consist of one, each combination of more than one, or all of the described elements, acts, or components. Any references to embodiments or elements or acts of the systems, apparatuses, methods, computer-readable mediums, and computer programs herein referred to in the singular may also embrace embodiments including a plurality of these elements, and any references in plural to any embodiment or element or act herein may also embrace embodiments including only a single element. References in the singular or plural form are not intended to limit the presently disclosed systems, apparatuses, methods, computer-readable mediums, and computer programs, their components, acts, or elements to single or plural configurations. References to any act or element being based on any information, act or element may include embodiments where the act or element is based at least in part on any information, act, or element. Any embodiment disclosed herein may be combined with any other embodiment, and references to “an embodiment,” “some embodiments,” “an alternate embodiment,” “various embodiments,” “one embodiment” or the like are not necessarily mutually exclusive and are intended to indicate that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment. Such terms as used herein are not necessarily all referring to the same embodiment. Any embodiment may be combined with any other embodiment, inclusively or exclusively, in any manner consistent with the aspects and embodiments disclosed herein. References to “or” may be construed as inclusive so that any terms described using “or” may indicate any of a single, more than one, and all of the described terms. Where technical features in the drawings, detailed description or any claim are followed by reference signs, the reference signs have been included for the sole purpose of increasing the intelligibility of the drawings, detailed description, and claims. Accordingly, neither the reference signs nor their absence have any limiting effect on the scope of any claim elements. First Example Embodiment FIG.1is a schematic illustration of an apparatus100according to a first example embodiment herein, for designating a location of an OCT scan to be performed by an OCT scanner (not shown) to image a portion of the retina of a subject's eye. The apparatus100may designate such a location on a surface of the retina by generating OCT scan location data145indicative of one or more control parameter values of the OCT scanner for controlling the OCT scanner such that its scan covers a particular region of the retina. The one or more control parameter values of the OCT scanner may, for example, correspond to an angular displacement of one or more beam-scanning mirrors (not shown) of the OCT scanner that define, e.g., a point on the retina where the OCT scan is to be performed, or a point on the retina serving as a reference point for setting the location of the OCT scan (e.g., a point on which the OCT scan is to be centred). In this regard, it should be noted that the OCT scan to be performed by the OCT scanner may be, by example and without limitation, an A-scan (in which two or more OCT measurements are performed at different points in a depth direction of the retina, all for a common location on the surface of the retina), a B-scan (in which two or more A-scans are performed, each at a different coordinate value taken along a first direction (e.g., a direction along an x-axis) on the surface of the retina) or a C-scan (in which two or more B-scans are performed, each at a different coordinate value taken along a second, different direction (e.g., an orthogonal, y-axis direction) on the surface of the retina). As illustrated inFIG.1, the apparatus100comprises a display device110, a touch-sensitive input device120, an image manipulation module130and a scan location designation module140. The display device110is configured to display an image200, as shown inFIG.2, for example, comprising a number of elements including a background image220of at least a portion of the retina and a foreground graphical planning element210that is superimposed on the background image220, for designating a location on the retina of the OCT scan that is to be performed. The display device110may, as in the present embodiment, form part of a touch-screen device150, which integrates the functionalities of the display device110and the touch-sensitive input device120. Thus, the display device110and the touch-sensitive input device120may be an integrally formed user input/output interface that forms the touch-screen device150. Alternatively, the display device110may be an LCD screen or any other type of visual display unit (VDU), and/or may be separate from the device120. The background image220may be obtained in a manner as will be described further below. The foreground graphical planning element210may, as in the illustrated embodiment, have a rectangular shape, as shown inFIG.2. As a further alternative, the foreground graphical planning element210may define a two-dimensional region whose boundary is not rectangular but may take any other predetermined shape suitable for designating a two-dimensional region of the retina for performing a C-scan, such as a circle or an ellipse, for example and without limitation.FIG.3(a)shows an alternative example of the image, labelled300a, comprising the background image220and a circular foreground graphical planning element310a, whileFIG.3(b)shows another example of the image, labelled300b, comprising the background image220and an elliptical foreground graphical planning element310b. Moreover, the foreground graphical planning element210need not define a two-dimensional region on the background image220and may alternatively take the form of a point superimposed on the background image220(for designating the location of an A-scan) or a line segment superimposed on the background image220(for designating the location of an B-scan).FIGS.3(c) and3(d)show alternative examples of the image, comprising the background image220and foreground graphical planning element, labelled310cand310d, respectively, in the form of line segments of different lengths. The foreground graphical planning element210may provide a proportionate representation of a region of the retina to be captured in the OCT scan. However, it should be noted that the shape of the foreground graphical planning element210need not in general be indicative of the shape of the region of the retina to be covered by the OCT scan. For example, the foreground graphical planning element210may take the form of a point whose location on the background image220is understood to have a predefined positional relationship to the (one- or two-dimensional) region of the retina on the background image220that is to be covered by the scan. By example, the point could serve to designate a centre of a one- or two-dimensional region to be scanned, an end of a one-dimensional region to be scanned, a corner of a two-dimensional region to be scanned, or the like. The location of the foreground graphical planning element210on the background image220in the coordinate space in which each extends is defined by a scan graphic locator, comprising coordinates of a predefined portion of the foreground graphical planning element210(e.g., the centre of a rectangular foreground graphical planning element210) in an image pixel coordinate system of the background image220, for example. The location of the foreground graphical planning element210on the background image220is set by the values of the scan graphic locator. In some example embodiments herein, the foreground graphical planning element210has a shape that is manipulable/changeable. By example, in those embodiments the foreground planning element210may be controlled to select any of the foregoing or other shapes for the element210, such that the element210takes on the selected shape(s), when selected. Also, one or more of the shapes may be, for example, at least one point, line segment, a two-dimensional shape, or a three-dimensional shape. Also in one example embodiment herein, the foreground graphical planning element210can be controlled to expand or reduce its size, and/or to deform at least part thereof. Each of the foregoing functionalities can be performed via a user interface, such as, by example and without limitation, touch-sensitive input device120. The background image220may, as in the present embodiment, be produced by a scanning imaging system (not shown), such as, for example, an ultra-wide-field scanning laser ophthalmoscope (UWF-SLO) capable of generating an ultra-wide field image of up to 80% of the retinal surface. Alternatively, the background image220may be produced by other types of scanning imaging systems, such as, for example, a scanning laser ophthalmoscope (SLO), a combined SLO-OCT scanner, a fundus camera or any other suitable type of retinal imaging system. The background image220may be a Red-Green (RG) reflectance image or an image from other fluorescence modes, or any other suitable type of image. The apparatus100may acquire the background image220of a portion of the retina by any suitable means known to those versed in the art. For example, the apparatus100may receive the background image220from a scanning imaging system (not shown) via a direct communication link (which may be provided by any suitable wired or wireless connection, e.g. a Universal Serial Bus (USB) or a Bluetooth™ connection), an indirect communication link (which may be provided by a network comprising a Local Area Network (LAN), a Wide Area Network (WAN) and/or the Internet), or via a memory in which the background image220is stored, although these examples are not exclusive. Furthermore, the background image220may be acquired by the apparatus100(and may furthermore subsequently be processed to designate a location of an OCT scan to be performed on a retina of an eye, as described below) as the background image data is being generated by the scanning imaging system, i.e., the image data may be acquired “on the fly”, without waiting for the scanning imaging system to finish generating all of the image data that forms the background image220of the at least a portion of the retina. The touch-sensitive input device120has a touch-sensitive surface125, with which the user may interact directly using one or more digits of their hand, or indirectly using an implement such as a stylus, for example. The touch-sensitive input device120is configured to generate respective touch interaction data127indicative of at least one sequence of detected locations for each of a plurality of touch interactions of the user with the touch-sensitive surface125. In other words, the touch-sensitive input device120logs (for example, by recording) detected locations of one or more points of contact between, e.g., a finger of the user, a stylus held by the user or the like and the touch-sensitive surface125during the course of a touch interaction between the user and the touch-sensitive input device120, such that the detected locations are recorded in the sequence (order) in which they were detected. The ordering of the detected locations may be recorded using timestamps assigned to the detected locations, by sequential numbering of the detected locations, or in any other suitable manner. For example, where the touch interaction takes the form of a single-touch drag (where the user touches the touch-screen with a finger (or a tool such a stylus) and then drags the finger (or tool, as the case may be) across its surface while drawing a line or a curve or any other shape/pattern on the touch-sensitive surface125), for example, the touch-sensitive input device120logs detected locations of the point of contact between the user's finger (or the tool) and the touch-sensitive surface125of the touch-sensitive input device120during the course of the single-touch drag, as a single sequence of detected locations. The touch-sensitive input device120may determine that the sequence of detected locations relates to a single-touch drag if the number of locations in the sequence exceeds a predetermined threshold number (for example, the number of locations may correspond to 20 pixels) or where the duration of the touch interaction corresponding to the sequence of detected locations exceeds a predetermined threshold duration (e.g. 300 ms), for example. The predetermined threshold number or the predetermined threshold duration (as the case may be) may be configurable and could be adjusted by trial and error, for example, to optimise the performance of the touch-sensitive input device120. Where the touch interaction is a double-tap of at least one finger of the user (or the stylus or other tool for interacting with the touch-sensitive input device120, as the case may be) on the touch-sensitive surface125, the touch-sensitive input device120may determine that the touch interaction is a double-tap by determining that the durations of the two interactions constituting the double-tap are both below respective threshold values (which may be the same value as (or a different value from), for example, the predetermined threshold value noted above that may be used to identify a touch interaction as a single-touch drag) and, optionally, that the interval between the end of the first interaction and the start of the second interaction is below a threshold value. Where the touch interaction is identified as a double-tap, the touch-sensitive input device120may log detected locations of the points of contact between the user's finger (or the tool) and the touch-sensitive surface125made during the course of the double-tap interaction, which will usually be the same or almost the same. It should be noted that the touch-sensitive input device120may be configured to generate touch interaction data127indicative of more than one sequence of detected locations for some kinds of touch interaction of the user with the touch-sensitive surface125. For example, in the case of a pinch interaction of the user with the touch-sensitive input device120, where the user places a first and a second digit of their hand (often the thumb and forefinger) on the touch-sensitive surface125and moves those digits closer together (“pinching in”) or further apart (“pinching out”) while maintaining contact between each of the digits and the touch-sensitive surface125, the touch-sensitive input device120logs detected locations of the respective points of contact between the first and second digits and the touch-sensitive surface125during the course of the pinch interaction, as a respective first and second sequence of detected locations. Since the locations of the points of contact are recorded as sequences, the touch-sensitive input device120is able to determine whether the user is moving their digits closer together or further apart, based on whether the distance between corresponding detected locations in the first and second sequences (i.e., detected locations appearing at corresponding positions in the first and second sequences) is decreasing or increasing, respectively, along the sequence. As noted above, the touch-sensitive input device120and the display device110of the present embodiment are integrated in a touch-screen device150. However, as also noted above, in other embodiments, the touch-sensitive input device120may be separate from the display device110and may, for example, be provided in the form of a track-pad that is provided as part of a computer keyboard or as a stand-alone peripheral component, although these examples are not exclusive. The image manipulation module130is configured to determine, based on each of the touch interaction data127generated by touch-sensitive input device120, a respective image manipulation that is to be performed on at least part of the image200being displayed by the display device110. In other words, the image manipulation module130determines, from the touch interaction data, which type of manipulation is to be performed to at least part of the image200. Each image manipulation may include, by example and without limitation, one or more of: (i) a resizing of both the foreground graphical planning element210and the background image220by a common scaling factor while maintaining the location of the foreground graphical planning element210with respect to the background image220; (ii) a translation of the foreground graphical planning element210relative to the background image220; and (iii) a panning of at least part of the image200being displayed, i.e., a panning of the foreground graphical planning element210and the background image220while maintaining the location of the foreground graphical planning element210with respect to the background image220. The image manipulation module130is further configured to apply the determined image manipulation to the image200being displayed on the display device110in response to each of the touch interactions so as to generate a respective updated image that is displayed on the display device110. By way of example, where the plurality of touch interactions comprise a single-touch drag operation performed by the user on the touch-sensitive surface125of the input device120, the touch-sensitive input device120generates touch interaction data127indicative of a sequence of detected locations for the single-touch drag, the sequence comprising a first detected location corresponding to a beginning of the single-touch drag and a second detected location corresponding to an end of the single-touch drag, as well as one or more intermediate detected locations that are between the first and second detected locations. The image manipulation module130may make use of a mapping to convert detected locations of a touch interaction on the touch-sensitive surface125to corresponding points on the background image220being displayed on the display device110during the touch interaction. In this case, where a location on the background image220corresponding to the first detected location (i.e., the location on the image220to which the first detected location is mapped) is within a predetermined distance from the foreground graphical planning element210(this distance being expressed in terms of any appropriate distance units defined in a coordinate system of the background image220, from the first detected location in the sequence of detected locations to, e.g. a centre-of-mass, or the closest point on the boundary, of the foreground graphical planning element210), the image manipulation module130is configured to determine the image manipulation for the single-touch drag to comprise a translation of the foreground graphical planning element210relative to the background image220by an amount that is based on a distance between the first and second detected locations and in a direction that is based on a direction of the second detected location from the first detected location. It should be noted that the predetermined distance may also be zero, in which case, for example, the first detected location is required to be on the external boundary of, or within, the foreground graphical planning element210. For example, where the user touches the foreground graphical planning element210and moves their finger (or the stylus, as the case may be) across the touch-sensitive surface125, the image manipulation module130determines the image manipulation to be a single-touch drag of the foreground graphical planning element210, and accordingly determines the image manipulation for the single-touch drag to comprise a movement of the foreground graphical planning element210relative to the background image220by an amount that is based on a distance between the first and second detected locations and in a direction that is based on a direction of the second detected location from the first detected location. FIGS.4(a) and4(b)are illustrative examples of how the image manipulation module130may update the displayed image200in response to a touch interaction in the form of a single-touch drag operation performed by the user on the touch-sensitive surface125of a touch-sensitive input device120in the form of touch screen device, for example. The user touches the foreground graphical planning element210at a first touch location410on the touch screen device, and drags their digit (or stylus tip, as the case may be) horizontally across the surface of the touch screen device, to a second location, labelled420-1inFIG.4(a)and420-2inFIG.4(b). In an illustrated example embodiment herein, the image manipulation module130determines the touch interaction to be a single-touch drag, and that the (mapped) location on the background image220which corresponds to the first detected location is within the predetermined distance from the foreground graphical planning element210, as described above. Accordingly, the module130updates the image200by translating the foreground graphical planning element210horizontally across the touch screen device, from an initial location (e.g., a location where the foreground graphical planning element is represented by a solid line inFIGS.4(a) and4(b)) to a final location (e.g., a location where the foreground graphical planning element is represented by a dashed line), by an amount of displacement corresponding to the distance between the first location410and the second location420-1or420-2, whilst the background image220remains unchanged in the two images. The image manipulation module130may more generally be configured to determine the image manipulation for the single-touch drag to comprise a translation of the foreground graphical planning element210relative to the background image220by an amount of displacement that scales linearly or non-linearly with the distance between the first and second detected locations and in a direction in the coordinate space represented on the display device110that is similar to, and preferably the same as, the direction of the second detected location from the first detected location on the touch-sensitive surface125of the touch-sensitive input device120. The image manipulation module130may be configured to allow the user to adjust the linear or non-linear scaling between the translation amount and the distance between the first and second detected locations for the single-touch drag of the foreground graphical planning element210, thereby effectively adjusting the sensitivity of the touch-sensitive input device120for the single-touch drag of the foreground graphical planning element210. In other words, the user can specify the amount by which the element210is displaced (whether linearly or non-linearly) for each unit of the single-touch drag displacement, to thereby control/adjust the sensitivity. In other embodiments herein, the sensitivity is predetermined by pre-programming in the image manipulation module130, or the user may specify a sensitivity or select a default sensitivity. The image being displayed may be updated continually, for example at regular intervals, during the course of the single-touch drag, so that the value of the scan graphic locator is updated to change the location of the foreground graphical planning element210on the background image220effectively in real-time, while the user is performing the drag across the touch-sensitive input device120). Also in one example embodiment herein, in response to the changing of the graphical planning element210, the displayed image200is updated in a continuous manner, at predetermined intervals during the changing of the scan graphic locator in response to the single-touch drag, or after a predetermined delay. Alternatively, in another example embodiment, the image being displayed may be updated only after the single-touch drag operation has ended, i.e. after the user lifts their digit or stylus off the touch-sensitive input device120. Which particular type of updating of the displayed image200is provided in response to the single-touch drag can be predetermined, or can be pre-specified/pre-programmed by user-command. It should be noted that updating of the scan graphic locator to reflect the changing location of the point of contact of the user's digit/stylus in accordance with the aforementioned scaling (whether user-adjustable or not) may be conditional upon the scan graphic locator value being within a predetermined range of values bounded by predetermined bounds (e.g., a predetermined range of spatial coordinate values), and the predetermined range/bounds may be pre-programmed in the apparatus100or specified by user-command. In one example embodiment herein, the predetermined range/bounds are employed to ensure that the user cannot designate a region for the OCT scan where an OCT scan cannot in fact be performed for practical reasons. Thus, in one example, to the extent that the drag of graphical planning element210by the user causes the graphic locator value to exceed the bounds of the predetermined range, the graphic planning element210is no longer displaced and/or updated further beyond where the corresponding bound is reached by the scan graphic locator value. In one example embodiment herein, in the case where a value of the scan graphic locator is caused to exceed a predetermined bound of the range, in response to the drag by the user, then the scan graphic locator is maintained at a coordinate value corresponding to the predetermined bound, and the graphic planning element120is displayed at a position/orientation corresponding to that value of the scan graphic locator. On the other hand, in a case of a single-touch drag where the location on the background image220corresponding to first detected location is not within the predetermined distance from the foreground graphical planning element210as described above, the image manipulation module130is configured to determine the image manipulation for the single-touch drag to comprise a panning of the image200being displayed (in other words, a common translation of both the background image220and the foreground graphical planning element210, which preserves the location and orientation of the foreground graphical planning element210relative to the background image220). In the present example embodiment, the amount of displacement resulting from the panning is based on the distance between the first and second detected locations, and the direction of the panning displacement is based on the direction of the second detected location from the first detected location. Thus, for example, in a case where the user touches the touch-sensitive surface125at a location thereon corresponding to a location in the background image220that is far enough away (i.e., not with the predetermined distance) from (or not on) the foreground graphical planning element210, and moves their finger (or the stylus, as the case may be) across the touch-sensitive surface125, the image manipulation module130determines the image manipulation to be a panning of the image200, and accordingly determines that both the background image220and the foreground graphical planning element210are to be moved by an amount that is based on a distance between the first and second detected locations and in a direction based on that extending from the first detected location to the second detected location. In this case, the scan graphic locator maintains its position on the background image220, both before and after the panning. FIG.5is an illustrative example of how the image manipulation module130may update the displayed image200in response to a touch interaction in the form of a single-touch drag operation performed by the user on the touch screen device, wherein the user does not touch the foreground graphical planning element210, but instead places their digit or a tip of a stylus at a first touch location510on the touch screen device, wherein the first touch location510is detected as a first detected location. In the illustrated example, a location on the background image220corresponding to (i.e., mapped to) the first detected location is assumed to not be within a predetermined distance from the foreground graphical planning element210, and the user drags the digit/stylus tip across the surface of the touch screen device, to a second location520. The image manipulation module130determines the touch interaction to be a single-touch drag, and determines that the location on the background image220corresponding to the first detected location is not within the predetermined distance from the foreground graphical planning element210, as described above, and accordingly updates the image200by translating both the foreground graphical planning element210and the background image220across the touch screen device by an amount corresponding to the distance between the first location510and the second location520, and in a direction based on that extending from the first location510to the second location520. InFIG.5, the foreground graphical planning element210and a surrounded portion of the background image are bounded by a solid line, while the foreground graphical planning element210and the surrounded portion of the background image in the updated image are bounded by a dashed line. The image manipulation module130may more generally determine the image manipulation for the panning operation to comprise a translation of both the foreground graphical planning element210and the background image220by an amount that scales linearly or non-linearly with the distance between the first and second detected locations, and in a direction on the display device110that is similar to, and preferably the same as, the direction of the second detected location from the first detected location on the touch-sensitive surface125of the touch-sensitive input device120. The image manipulation module130may be configured to allow the user to adjust the linear or non-linear scaling between the translation amount and the distance between the first and second detected locations for the panning operation, thereby effectively adjusting the sensitivity of the touch-sensitive input device120for the panning operation. In other words, the user can specify the amount by which the element210and image220are displaced (whether linearly or non-linearly) for each unit of displacement along the (imaginary) line extending from the first detected location to the second detected location, to thereby control/adjust the sensitivity. In some embodiments herein, the sensitivity is predetermined by pre-programming in the image manipulation module130, and the user can select between the pre-programmed sensitivity and a sensitivity specified by the user. Where the plurality of touch interactions comprise a pinch operation performed by the user on the touch-sensitive surface125of the input device120, the touch-sensitive input device120generates touch interaction data127indicative of a first sequence of detected locations and a second sequence of detected locations, as described above. In this case, the image manipulation module130may be configured to determine the image manipulation for the pinch to comprise a resizing of both the foreground graphical planning element210and the background image220by a common scaling factor which is based on a difference between (i) a distance between the first detected locations in the first and second sequences of detected locations, and (ii) a distance between the final detected locations in the first and second sequences of detected locations; in other words, a difference between the separation of the detected locations on the touch-sensitive surface125at the beginning of the pinch operation and the separation of the detected locations on the touch-sensitive surface125at the end of the pinch operation. The image manipulation module130may alternatively be configured to adjust the common scaling factor (and thus adjust the size of the element210and background image220) based on a calculated distance from either of the two touch locations (i.e. the points of contact mentioned above) to a predetermined reference location, such as, by example and without limitation, a location that is equidistant from the initial touch locations of the pinch operation, when either of the touch locations are detected to change. FIG.6(a)is an illustrative example of how the image manipulation module130may update the displayed image200in response to a touch interaction in the form of a pinch operation performed by the user on the touch screen device, but where the user does not touch the foreground graphical planning element210, and instead places their digits (typically the thumb and forefinger of a hand, although the pinch operation may more generally be performed using any two digits, and not necessarily those of a same hand) at respective first touch locations,610-1and610-2, and drags the digits away from each other across the surface of the touch screen device, to respective second touch locations,620-1and620-2. The image manipulation module130determines the touch interaction to be a pinch operation, and accordingly updates the image200by resizing both the foreground graphical planning element210and the background image220by a common scaling factor that may, as in the present example embodiment, be based on the difference between the separation of the detected locations610-1and610-2, and/or the separation of the detected locations620-1and620-2. InFIG.6(a), the foreground graphical planning element210and a surrounded portion of the background image in the initially-displayed image are bounded by a solid line, while the foreground graphical planning element210and the portion of the background image in the updated image are bounded by a dashed line. In the case of the pinch operation, the updating of the displayed image is independent of the initial placement of the digits on the touch screen (or other touch-sensitive input device), i.e. at the start of the touch interaction, and depends only on the relative movement of the points of contact between the digits and the touch-sensitive surface125in the pinch operation. Thus, for example, where the relative movement of the points of contact between the digits and the touch-sensitive surface125is the same as those in the example ofFIG.6(a), but the locations of the initial points of contact of the digits with the touch-sensitive surface125are different than those in the example ofFIG.6(a), then the updated image will be the same, as illustrated inFIGS.6(b) and6(c). In other words, regardless of where the two initial points of contact of the digits with the touch-sensitive surface125are (i.e., both over the foreground graphical planning element210, both over the background image220, or one over the foreground graphical planning element210and the other over the background image220), the image manipulation module130behaves in the same way, by updating the displayed image200such that the foreground graphical planning element210and the background image220zoom together, with the location and orientation of the foreground graphical planning element210with respect to the background image220being retained. As in the case of the single-touch drag, the image may be updated continually during the course of the pinch interaction, at predetermined intervals during the pinch interaction, after a predetermined delay, or after the operation has ended. An example of a case where touch interactions include a double-tap operation will now be described. Where touch interactions comprise a double-tap operation performed by the user on the touch-sensitive surface125of the input device120, the image manipulation module130is configured to determine the image manipulation for the double-tap operation to be a resizing of both the foreground graphical planning element210and the background image220by a common predetermined factor. The image manipulation module130may, as in the present embodiment, be configured to determine the image manipulation for the double-tap operation to be such that a portion of the image200provided at a location in the image200corresponding to a location of the double-tap on the touch-sensitive surface125appears at the same location in the updated image, allowing the image200(including both the background image220and the foreground graphical planning element210) to be zoomed or visually expanded manner to enable closer examination of a region of interest in a quick and convenient way. As illustrated inFIGS.7(a) and7(b), the zooming/expanding is independent of whether the double-tap occurs over the foreground graphical planning element210(as illustrated inFIG.7(a)), or over the background image220(this alternative being illustrated inFIG.7(b)). Thus, regardless of where the points of contact on the touch-sensitive surface125occur in the double-tap operation (e.g., both over the foreground graphical planning element210or both over the background image220), the image manipulation module130behaves on the same way, updating the displayed image200such that the foreground graphical planning element210and the background image220zoom/expand together, with the location and orientation of the foreground graphical planning element210with respect to the background image220being retained after the zoom/expansion. The image manipulation module130may alternatively be configured to determine the image manipulation for the double-tap operation to comprise a translation of the image200being displayed, such that a portion of the image200provided at a location corresponding to a location of the double-tap on the touch-sensitive surface125appears at the centre of the updated image, for example. As a further alternative, the image manipulation module130may be configured to determine the image manipulation for the double-tap operation to be such that a portion of the image200provided at the centre of the image200also appears at a centre of the updated image. In an alternative embodiment, the image manipulation module130may be configured to determine the image manipulation for a double-tap operation performed using a single finger to comprise a translation of the image200being displayed such that a portion of the image200provided at a location corresponding to a location of the double-tap on the touch-sensitive surface125appears at a centre of the updated image, and to determine the image manipulation for a double-tap operation performed using more than one finger to be such that a portion of the image200provided at the centre of the image200also appears at the centre of the updated image, thus combining the functionalities described above. Although the double-tap operations are described to yield a zooming-in or expanding of the displayed image200in the foregoing examples, they may alternatively allow the user to zoom out of the currently displayed image200. In this case, where the updated image fills the screen of the display device110, the double-tap to zoom out would not cause the double-tap position to be retained. That is, a portion of the image200provided at a location in the image200corresponding to a location of the double-tap on the touch-sensitive surface125will not appear at the same location in the updated image, as described above. It should be noted that at least some of the user interactions described above may be combined, with the image manipulation module130determining the image manipulation to comprise a combination of one or more of the image manipulations described above. For example, the image manipulation module130may track the coordinate of a mid-point of an imaginary line joining the first and second detected touch locations (contact points) during a pinch operation, and update the displayed image by panning it in accordance with the movement of the mid-point, whilst at the same time zooming the image in accordance with the changing distance between the first and second touch locations. Of course, this example is non-limiting and any other types of combinations of image manipulations also can be provided as well. When a touch interaction event occurs on the background image220or the foreground graphical planning element210, no action with respect to image220and/or element210may be performed until it is confirmed that the touch interaction event is not a double-tap. If it is confirmed that the touch interaction is not a double tap, no action with respect to the foreground graphical planning element210may be performed. Thus, the scan graphic locator may maintain the foreground graphical planning element210's position on the background image220when, for example, panning or zooming due to a double-tap touch interaction event occurs. The proportionate distance of the position of the foreground graphical planning element210from the centre of the image200may be updated when either image manipulation event occurs. This distance may be calculated with respect to a reference position for each position change to prevent any “drifting” that would occur if the calculation was made from a relative position. The reference position may be set when the initial touch or double-tap is made on the background image220, and, in one example embodiment, the reference position is the location of where the touch or double-tap is detected. Also in one example embodiment herein, the reference position can be reset if a touch up or touch leave event occurs. Referring again toFIG.1, the scan location designation module140will now be described. The scan location designation module140is configured to generate OCT scan location data145indicative of the location of the OCT scan that is to be performed on the retina based on a location of the foreground graphical planning element210on the background image220of the retina in at least one of the updated images, such as, for example, an updated image resulting from a most recent image manipulation comprising a translation of the foreground graphical planning element210relative to the background image220, although this example is non-limiting. The scan location designation module140may be configured to generate the OCT scan location data145on the basis of the location of the foreground graphical planning element210on the background image220in any suitable way. For example, the OCT scanner (not shown) may perform an OCT retinal scan covering an anatomical feature, such the fovea, that is generally recognisable in images of different modality, and generate data comprising OCT measurement values and corresponding scan parameter values that are indicative of, for example, the angular displacements of a first (e.g. horizontal) mirror and a second (e.g., vertical) mirror of the OCT scanner that are arranged to deflect the OCT sample beam across the surface of the retina. In an example embodiment involving such a case, the scan location designation module140may make use of the generated data and a mapping between locations in an obtained OCT retinal scan and corresponding locations in the background image220(which may be determined by comparing the locations of the fovea or any other recognisable anatomical feature(s) in the OCT retinal scan image and the background image220) to calculate the scan parameter values corresponding to the location of the foreground graphical planning element210on the background image220. The location of the foreground graphical planning element210on the background image220may be defined in any suitable way. For example, where the foreground graphical planning element210takes the form of a rectangle, as illustrated inFIG.2, the location of the foreground graphical planning element210may be taken to be the location of a geometrical centre (centre of mass) of the rectangle on the background image220. Where the foreground graphical planning element210is a line segment, the location of the OCT scan indicated by OCT scan location data145may be based on a middle point or either end of the line segment, for example. The scan location designation module140may, as in the present embodiment, be configured to generate OCT scan location data145that are indicative not only of the location of the OCT scan to be performed by the OCT scanner but also the size of that OCT scan, the size being based on at least one dimension of the foreground graphical planning element210in at least one of the updated images. For example, where the foreground graphical planning element210is a line segment for designating the location of a B-scan to be performed by the OCT scanner (not shown), whose length is adjustable by the user, the scan location designation module140may include in the generated scan location data, in addition to data indicative of the location of the OCT scan described above, data indicative of the length of the OCT scan, on the basis of the length of the line segment selected or otherwise set by the user. The width and/or height of a rectangular foreground graphical planning element210may likewise be adjustable by the user to allow the width and/or height of a rectangular OCT scan region to be set by the scan location designation module140, in accordance with the user's requirements. The scan location designation module140may be configured to generate OCT scan location data145indicative of both the location and size of the OCT scan that is to be performed on the retina based on the location (on the background image220) and the size of the foreground graphical planning element210in an updated image resulting from a most recent image manipulation comprising a translation of the foreground graphical planning element210relative to the background image220and a most recent manipulation comprising a resizing of the foreground graphical planning element210. The OCT scan location data145may be provided to an OCT scanner and used to control the OCT scanner to perform an OCT scan on the location on the retina indicated by the OCT scan location data145. In order to do so, the OCT scanner may be configured to transformed the location on the retina indicated by the OCT scan location data145into a corresponding set of one or more control parameters for steering the OCT scanner to perform its scan at substantially the same location on the retina as that indicated by the OCT scan location data145. This can be done in one of a number of different ways. For example, the OCT scanner may use a mapping between the locations on the retina and corresponding values of the control parameters, which may be provided in the form of a look-up table or a function defined by a set of parameters, for example. The mapping may be determined by calibration, using techniques known to those skilled in the art. The apparatus100can thus allow the user to easily and conveniently explore all areas of the image200of a portion of the retina, varying the zoom level and/or panning across the image200as necessary, and moving the foreground graphical planning element210where needed during this exploration in order to designate a region of interest for the OCT scan. Accordingly, the apparatus100can allow an OCT scan to be planned anywhere on the background image220, not merely in a magnified area of interest shown in a static background image as in conventional approaches. Even in situations in which the user of the apparatus100is aware of an approximate intended location of the OCT scan (for example, in a case where the retina of the patient has been subject to an OCT scan previously), the features of the apparatus100allow the user to easily and conveniently explore the area around the approximate intended location of the OCT scan to determine whether there are further features of interest. Second Embodiment FIG.8illustrates a second example embodiment of the invention, provided in the form of a computer program800for designating a location of an OCT scan to be performed on a retina of an eye. The computer program800comprises a display control software module810, an image manipulation software module820, and a scan location designation software module830. The computer program800comprises computer-readable instructions that may be executed by programmable signal processing hardware, an example of which is illustrated inFIG.9. The computer-readable instructions may be executed by a computer processor, such as, by example, processor920ofFIG.9, to enable the processor920to perform any of the methods described herein. The example of a programmable signal processing hardware900shown inFIG.9comprises a communication interface (I/F)910for receiving the touch interaction data127described above (e.g., from device120), and outputting display control signals for controlling the display device110to display the image200and updated versions thereof, as also described above. The signal processing apparatus900further comprises processor (e.g., a Central Processing Unit, CPU, or Graphics Processing Unit, GPU)920, a working memory930(e.g., a random access memory) and an instruction store940storing computer-readable instructions which, when executed by the processor920, cause the processor920to perform various functions including those of the image manipulation module130and the scan location designation module140described above, as well as any method described herein. The instruction store940may store program800and may comprise a ROM (e.g., in the form of an electrically-erasable programmable read-only memory (EEPROM) or flash memory) which is pre-loaded with the computer-readable instructions. Alternatively, the instruction store940may comprise a RAM or similar type of memory, and the computer-readable instructions of the computer program800can be input thereto or otherwise received from computer program storage, such as a non-transitory, computer-readable storage medium950in the form of a CD-ROM, DVD-ROM, etc., or from a computer-readable signal960carrying the computer-readable instructions. In the present embodiment, the combination970of the hardware components shown inFIG.9, including the processor920, the working memory930and the instruction store940, is configured to perform the functions of the image manipulation module130and the scan location designation module140described above, and is configured to exchange information (including the touch interaction data and the display control signals) with the display device110and the touch-sensitive input device120. It should be noted, however, that the image manipulation module130and the scan location designation module140may alternatively be implemented in non-programmable hardware, such as an application-specific integrated circuit (ASIC). It will therefore be appreciated that the display control software module810shown inFIG.8, when executed by the processor920illustrated inFIG.9, causes the processor920to generate, based on image data defining the background image220and the foreground graphical planning element210, display control signals for controlling a display device110to display the image200defined by the image data. The image manipulation software module820, when executed by the processor920, causes the processor920to receive respective touch interaction data127indicative of at least one sequence of detected locations on a touch-sensitive surface125of the touch-sensitive input device120for each of a plurality of touch interactions of a user with the touch-sensitive surface125, and determine, based on each of the touch interaction data127, a respective image manipulation to be performed on the image data that define the image200being displayed by the display device110(each image manipulation comprising, as described above, e.g., at least one of: a resizing of both the foreground graphical planning element210and the background image220by a common factor; a translation of the foreground graphical planning element210relative to the background image220; and a panning of the image200being displayed). The image manipulation software module820, when executed by the processor920, further causes the processor920to apply the determined image manipulation to the image data that define the image200being displayed by the display device110, in response to each of the touch interactions, so as to generate a respective updated image data defining an updated image that is to be displayed on the display device110, and causes the display control software module810to generate, based on the updated image data generated in response to each of the touch interactions, respective display control signals for controlling the display device110to display an updated image defined by the updated image data. The scan location designation software module830, when executed by the processor920, causes the processor920to generate OCT scan location data145indicative of the location of the OCT scan that is to be performed on the retina based on a location of the foreground graphical planning element210on the background image220of the retina in at least one of the updated images. Similar the first embodiment described above, where the plurality of touch interactions comprise a single-touch drag operation performed by the user on the touch-sensitive surface125of the input device120as described above, the image manipulation software module820may, when executed by the processor920, make use of a mapping to convert detected locations of a touch interaction on the touch-sensitive surface125to corresponding points on the background image220being displayed on the display device110during the touch interaction(s). Similar to the first embodiment, where a location on the background image220corresponding to the first detected location is within the predetermined distance from the foreground graphical planning element210, the image manipulation software module820causes the processor920to determine the image manipulation for the single-touch drag to comprise a translation of the foreground graphical planning element210relative to the background image220by an amount that is based on a distance between the first and second detected locations and in a direction that is based on a direction of the second detected location from the first detected location. It should be noted that the predetermined distance may also be zero, in which case the first detected location is required to be on the external boundary of, or within, the foreground graphical planning element210. Thus, where the user touches the foreground graphical planning element210and moves their finger (or the stylus, as the case may be) across the touch-sensitive surface125, the image manipulation software module820determines the image manipulation to be a single-touch drag of the foreground graphical planning element, and accordingly determines the image manipulation for the single-touch drag to comprise a movement of the foreground graphical planning element210relative to the background image220by a displacement amount that is based on a distance between the first and second detected locations and in a direction that is based on a direction of the second detected location from the first detected location. For example, the image manipulation software module820may be configured to determine the image manipulation for the single-touch drag to comprise a translation of the foreground graphical planning element210relative to the background image220by an amount that scales linearly or non-linearly with the distance between the first and second detected locations and in a direction on the display device110that is the same as the direction of the second detected location from the first detected location on the touch-sensitive surface125of the touch-sensitive input device120. The image manipulation software module820may cause the processor920to allow the user to adjust the linear or non-linear scaling between the translation amount and the distance between the first and second detected locations for the single-touch drag of the foreground graphical planning element210, thereby effectively adjusting the sensitivity of the touch-sensitive input device120for the single-touch drag of the foreground graphical planning element210. On the other hand, in a case of a single-touch drag where the location on the background image220corresponding to first detected location is not within the predetermined distance from the foreground graphical planning element210as described above, the image manipulation software module820, when executed by the processor920, causes the processor920to determine the image manipulation for the single-touch drag to comprise a panning of the image200being displayed (in other words, a common translation of both the background image220and the foreground graphical planning element210, which preserves the location of the foreground graphical planning element210relative to the background image220) by an amount that is based on the distance between the first and second detected locations and in a direction that is based on the direction of the second detected location from the first detected location. Thus, where the user touches the touch-sensitive surface125at a location therein corresponding to a location in the background image220that is far enough away (e.g., not within the predetermined distance) from (or not on) the foreground graphical planning element210and moves their finger (or the stylus, as the case may be) across the touch-sensitive surface125, the image manipulation software module820causes the processor920to determine the image manipulation to be a panning of the image200, and accordingly to determine that both the background image220and the foreground graphical planning element210are to be moved by a displacement amount that is based on a distance between the first and second detected locations and in a direction that is based on a direction extending from the first detected location to the second detected location. For example, the image manipulation software module820may cause the processor920to determine the image manipulation for the panning operation to comprise a translation of both the foreground graphical planning element210and the background image220by an amount that scales linearly or non-linearly with the distance between the first and second detected locations, and in a direction on the display device110that is the same as the direction of the second detected location from the first detected location on the touch-sensitive surface125of the touch-sensitive input device120. The image manipulation software module820may cause the processor920to allow the user to adjust the linear or non-linear scaling between the translation amount and the distance between the first and second detected locations for the panning operation, thereby effectively adjusting the sensitivity of the touch-sensitive input device120for the panning operation. Where the plurality of touch interactions comprise a pinch operation performed by the user on the touch-sensitive surface125of the input device120, the touch-sensitive input device120generates touch interaction data127indicative of a first sequence of detected locations and a second sequence of detected locations, as described above. In this case, the image manipulation software module820causes the processor920to determine the image manipulation for the pinch to comprise a resizing of both the foreground graphical planning element210and the background image220by a common scaling factor which is based on a difference between (i) a distance between the first detected locations in the first and second sequences of detected locations, and (ii) a distance between the final detected locations in the first and second sequences of detected locations; in other words, a difference between the separation of the detected first and second locations on the touch-sensitive surface125at the beginning of the pinch operation and the separation of the detected first and second locations on the touch-sensitive surface125at the end of the pinch operation. Where the plurality of touch interactions comprise a double-tap operation performed by the user on the touch-sensitive surface125of the input device120, the image manipulation software module820causes the processor920to determine the image manipulation for the double-tap operation to be a resizing of both the foreground graphical planning element210and the background image220by a common predetermined factor (e.g. a magnification by a factor of 2). The image manipulation software module820may, as in the present embodiment, cause the processor920to determine the image manipulation for the double-tap operation to be such that a portion of the image200provided at a location in the image200corresponding to a location of the double-tap on the touch-sensitive surface125appears at the same location in the updated image, allowing the image200(including both the background image220and the foreground graphical planning element210) to be zoomed or visually expanded for closer examination of a region of interest in a quick and convenient way. The image manipulation software module820may alternatively cause the processor920to determine the image manipulation for the double-tap operation to comprise a translation of the image200being displayed, such that a portion of the image200provided at a location corresponding to a location of the double-tap on the touch-sensitive surface125appears at a centre of the updated image. As a further alternative, the image manipulation software module8200may cause the processor920to determine the image manipulation for the double-tap operation to be such that a portion of the image200provided at the centre of the image200also appears at the centre of the updated image. In an alternative embodiment, the image manipulation software module820may cause the processor920to determine the image manipulation for a double-tap operation performed using a single finger to comprise a translation of the image200being displayed such that a portion of the image200provided at a location corresponding to a location of the double-tap on the touch-sensitive surface125appears at the centre of the updated image, and to determine the image manipulation for a double-tap operation performed using more than one finger to be such that a portion of the image200provided at the centre of the image200also appears at the centre of the updated image, thus combining the functionalities described above. Although the double-tap operations are described to yield a zooming-in (visual expanding) of the displayed image200in the foregoing, they may alternatively enable the user to zoom out of the currently displayed image200. In this case, where the updated image fills the screen of the display device110, the double-tap to zoom out does not cause the double-tap position to be retained, as described above. The scan location designation software module830causes the processor920to generate OCT scan location data145indicative of the location of the OCT scan that is to be performed on the retina based on a location of the foreground graphical planning element210on the background image220of the retina in at least one of the updated images, such as, for example, an updated image resulting from a most recent image manipulation comprising a translation of the foreground graphical planning element210relative to the background image220. The scan location designation software module830may cause the processor920to generate the OCT scan location data145on the basis of the location of the foreground graphical planning element210on the background image220in any suitable way. For example, the OCT scanner may perform an OCT retinal scan covering an anatomical feature, such the fovea, that is generally recognisable in images of different modality, and generate data comprising OCT measurement values and corresponding scan parameter values that are indicative of, for example, the angular displacements of a first (e.g. horizontal) mirror and a second (e.g. vertical) mirror of the OCT scanner that are arranged to deflect the OCT sample beam across the surface of the retina; in this case, the scan location designation software module830may cause the processor920to make use of the generated data and a mapping between locations in the OCT retinal scan and corresponding locations in the background image220(which may be determined by comparing the locations of the fovea or any other recognisable anatomical feature(s) in the OCT retinal scan image and the background image220) to calculate the scan parameter values corresponding to the location of the foreground graphical planning element210on the background image220. The location of the foreground graphical planning element210on the background image220may be defined in any suitable way, as described above with reference to the first embodiment. The scan location designation software module830may, as in the present embodiment, cause the processor520to generate OCT scan location data145that are indicative not only of the location of the OCT scan to be performed by the OCT scanner (not shown) but also the size of that OCT scan, the size being based on at least one dimension of the foreground graphical planning element210in at least one of the updated images. For example, where the foreground graphical planning element210is a line segment for designating the location of a B-scan to be performed by the OCT scanner, whose length is adjustable by the user, the scan location designation software module830may include in the generated scan location data, in addition to data indicative of the location of the OCT scan described above, data indicative of the length of the OCT scan, on the basis of the length of the line segment selected or otherwise set by the user. The width and/or height of a rectangular foreground graphical planning element210may likewise be adjustable by the user to allow the width and/or height of a rectangular OCT scan region to be set by the scan location designation software module830, in accordance with the user's requirements. The scan location designation software module830may cause the processor920to generate OCT scan location data145indicative of both the location and size of the OCT scan that is to be performed on the retina based on the location (on the background image220) and the size of the foreground graphical planning element210in an updated image resulting from a most recent image manipulation comprising a translation of the foreground graphical planning element210relative to the background image220and a most recent manipulation comprising a resizing of the foreground graphical planning element210. Other details of the operations and their variants that are performed by the image manipulation module130and the scan location designation module140in the first embodiment are applicable to operations of the image manipulation software module820and the scan location designation software module830, and will not be repeated here. It will be appreciated from the foregoing that the display control software module810, the image manipulation software module820and the scan location designation module830may perform a method as shown inFIG.10.FIG.10is a flow diagram showing a process1000by which the computer program800ofFIG.8designates a location of an optical coherence tomography, OCT, scan to be performed on a retina of an eye. In process S10ofFIG.10, the display control software module810is executed by the processor920and causes the processor920to generate display control signals for controlling a display device110to display an image200defined by the image data. Generating of the display control signals is based on image data defining a background image220of a portion of the retina and a foreground graphical planning element210for designating a location on the retina of the OCT scan to be performed. In process S20, the image manipulation software module820is executed by the processor920and causes the processor920to receive respective touch interaction data127indicative of at least one sequence of detected locations on a touch-sensitive surface125of a touch-sensitive input device120for each of a plurality of touch interactions of a user with the touch-sensitive surface125. In process S30, the image manipulation software module820is executed by the processor920and causes the processor920to determine, based on each of the touch interaction data127, a respective image manipulation to be performed on the image data that define the image200being displayed by the display device110, each image manipulation comprising at least one of: a resizing of both the foreground graphical planning element210and the background image220by a common factor; a translation of the foreground graphical planning element210relative to the background image220; and a panning of the image200being displayed. In process S40, the image manipulation software module820is executed by the processor920and causes the processor920to apply the determined image manipulation to the image data that define the image200being displayed by the display device110, in response to each of the touch interactions, so as to generate a respective updated image data defining an updated image that is to be displayed on the display device110. In process S50, the image manipulation software module820is executed by the processor920and causes the processor920to cause the display control software module810to generate, based on the updated image data generated in response to each of the touch interactions, respective display control signals for controlling the display device110to display an updated image defined by the updated image data. In process S60, the scan location designation software module830is executed by the processor920and causes the processor920to generate OCT scan location data145indicative of the location of the OCT scan that is to be performed on the retina based on a location of the foreground graphical planning element210on the background image220of the retina in at least one of the updated images. Other details of the operations and their variants that are performed by the computer program800of the second embodiment, as discussed above, are applicable to process1000ofFIG.10, and will not be repeated here. It will be appreciated that the embodiments described above provide functionality that goes beyond simple panning and zooming of the image, allowing the coordinates, size and position of the foreground graphical planning element on the background image to be maintained, and the user to seamlessly interact with either the foreground graphical planning element or the combination of the foreground graphical planning element and the background image without any additional steps. In the foregoing description, example aspects are described with reference to several example embodiments. Accordingly, the specification should be regarded as illustrative, rather than restrictive. Similarly, the figures illustrated in the drawings, which highlight the functionality and advantages of the example embodiments, are presented for example purposes only. The architecture of the example embodiments is sufficiently flexible and configurable, such that it may be utilized (and navigated) in ways other than those shown in the accompanying figures. Software embodiments of the examples presented herein may be provided as a computer program, or software, such as one or more programs having instructions or sequences of instructions, included or stored in an article of manufacture such as a machine-accessible or machine-readable medium, an instruction store, or computer-readable storage device, each of which can be non-transitory, in one example embodiment. The program or instructions on the non-transitory machine-accessible medium, machine-readable medium, instruction store, or computer-readable storage device, may be used to program a computer system or other electronic device. The machine- or computer-readable medium, instruction store, and storage device may include, but are not limited to, floppy diskettes, optical disks, and magneto-optical disks or other types of media/machine-readable medium/instruction store/storage device suitable for storing or transmitting electronic instructions. The techniques described herein are not limited to any particular software configuration. They may find applicability in any computing or processing environment. The terms “computer-readable”, “machine-accessible medium”, “machine-readable medium”, “instruction store”, and “computer-readable storage device” used herein shall include any medium that is capable of storing, encoding, or transmitting instructions or a sequence of instructions for execution by the machine, computer, or computer processor and that causes the machine/computer/computer processor to perform any one of the methods described herein. Furthermore, it is common in the art to speak of software, in one form or another (e.g., program, procedure, process, application, module, unit, logic, and so on), as taking an action or causing a result. Such expressions are merely a shorthand way of stating that the execution of the software by a processing system causes the processor to perform an action to produce a result. Some embodiments may also be implemented by the preparation of application-specific integrated circuits, field-programmable gate arrays, or by interconnecting an appropriate network of conventional component circuits. Some embodiments include a computer program product. The computer program product may be a storage medium or media, instruction store(s), or storage device(s), having instructions stored thereon or therein which can be used to control, or cause, a computer or computer processor to perform any of the procedures of the example embodiments described herein. The storage medium/instruction store/storage device may include, by example and without limitation, an optical disc, a ROM, a RAM, an EPROM, an EEPROM, a DRAM, a VRAM, a flash memory, a flash card, a magnetic card, an optical card, nanosystems, a molecular memory integrated circuit, a RAID, remote data storage/archive/warehousing, and/or any other type of device suitable for storing instructions and/or data. Stored on any one of the computer-readable medium or media, instruction store(s), or storage device(s), some implementations include software for controlling both the hardware of the system and for enabling the system or microprocessor to interact with a human user or other mechanism utilizing the results of the example embodiments described herein. Such software may include without limitation device drivers, operating systems, and user applications. Ultimately, such computer-readable media or storage device(s) further include software for performing example aspects of the invention, as described above. Included in the programming and/or software of the system are software modules for implementing the procedures described herein. In some example embodiments herein, a module includes software, although in other example embodiments herein, a module includes hardware, or a combination of hardware and software. While various example embodiments of the present invention have been described above, it should be understood that they have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant art(s) that various changes in form and detail can be made therein. Thus, the present invention should not be limited by any of the above described example embodiments, but should be defined only in accordance with the following claims and their equivalents. Further, the purpose of the Abstract is to enable the Patent Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The Abstract is not intended to be limiting as to the scope of the example embodiments presented herein in any way. It is also to be understood that the procedures recited in the claims need not be performed in the order presented. While this specification contains many specific embodiment details, these should not be construed as limitations on the scope of any inventions or of what may be claimed, but rather as descriptions of features specific to particular embodiments described herein. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. Having now described some illustrative embodiments and embodiments, it is apparent that the foregoing is illustrative and not limiting, having been presented by way of example. In particular, although many of the examples presented herein involve specific combinations of apparatus or software elements, those elements may be combined in other ways to accomplish the same objectives. Acts, elements and features discussed only in connection with one embodiment are not intended to be excluded from a similar role in other embodiments or embodiments. The apparatus and computer programs described herein may be embodied in other specific forms without departing from the characteristics thereof. The foregoing embodiments are illustrative rather than limiting of the described systems and methods. Scope of the apparatus and computer programs described herein is thus indicated by the appended claims, rather than the foregoing description, and changes that come within the meaning and range of equivalency of the claims are embraced therein.

11857257

DETAILED DESCRIPTION OF EMBODIMENTS There is described herein, by way of example embodiments, an apparatus for processing functional OCT image data, which has been acquired by an OCT imaging device scanning a retina of a subject while the retina is being repeatedly stimulated by a light stimulus, to generate image data defining an image that provides an indication of a response of the retina to the light stimulus. The apparatus comprises a receiver module configured to receive, as the functional OCT image data: OCT image data that has been generated by the OCT imaging device repeatedly scanning a scanned region of the retina over a time period; and stimulus data defining a sequence of stimulus indicators each being indicative of a stimulation of the retina by the light stimulus in a respective time interval of a sequence of time intervals that spans the time period. The apparatus further comprises a correlation calculator module configured to calculate a rolling window correlation between a sequence of B-scans that is based on the OCT image data and stimulus indicators in the sequence of stimulus indicators. The rolling window correlation may be calculated in a number of different ways. For example, the correlation calculator module may calculate the rolling window correlation between the sequence of B-scans and the stimulus indicators in the sequence of stimulus indicators by calculating, for each of a plurality of windowed portions of the sequence of B-scans, a respective product of a stimulus indicator in accordance which the retina was stimulated while OCT image data, on which at least one of the B-scans in the windowed portion of the sequence of B-scans is based, was being generated by the OCT imaging device, and at least a portion of each B-scan in the windowed portion of the sequence of B-scans. The correlation calculator module may alternatively calculate the rolling window correlation between the sequence of B-scans and the stimulus indicators in the sequence of stimulus indicators by calculating, for each stimulus indicator, a correlation between stimulus indicators in a window comprising the stimulus indicator and a predetermined number of adjacent stimulus indicators, and B-scans of the sequence of B-scans that are based on a portion of the OCT image data generated while the retina was being stimulated in accordance with the stimulus indicators in the window. Some example methods of calculating the rolling window correlation that may be employed by the correlation calculator module are set out in the following description of example embodiments. The apparatus set out above further comprises an image data generator module configured to use the calculated rolling window correlation to generate image data defining an image which indicates at least one of: the response of the scanned region of the retina to the light stimulus as a function of time; one or more properties of a curve defining the response of the scanned region R of the retina to the light stimulus as a function of time; and a spatial variation, in the scanned region of the retina, of one or more properties of the curve defining the response of the scanned region of the retina to the light stimulus as a function of time, the spatial variation being overlaid on an en-face representation of at least a portion the retina which includes the scanned region. There is also described in the following, by way of example embodiments, a computer-implemented method of processing functional OCT image data, which has been acquired by an OCT imaging device scanning a retina of a subject while the retina is being repeatedly stimulated by a light stimulus, to generate image data defining an image that provides an indication of a response of the retina to the light stimulus. The method comprises receiving, as the functional OCT image data: OCT image data that has been generated by the OCT imaging device repeatedly scanning a scanned region of the retina over a time period; and stimulus data defining a sequence S of stimulus indicators each being indicative of a stimulation of the retina by the light stimulus in a respective time interval of a sequence of time intervals that spans the time period. The method further comprises calculating a rolling window correlation between a sequence of B-scans that is based on the OCT image data and stimulus indicators in the sequence S of stimulus indicators, as mentioned above. The method further comprises using the calculated rolling window correlation to generate image data defining an image which indicates at least one of: the response of the scanned region of the retina to the light stimulus as a function of time; one or more properties of a curve defining the response of the scanned region of the retina to the light stimulus as a function of time; and a spatial variation, in the scanned region of the retina, of one or more properties of the curve defining the response of the scanned region of the retina to the light stimulus as a function of time, the spatial variation being overlaid on an en-face representation of at least a portion of the retina which includes the scanned region. Example embodiments herein will now be described in more detail with reference to the accompanying drawings. Embodiment 1 FIG.1is a schematic illustration of an apparatus100-1according to a first example embodiment, which is configured to process functional Optical Coherence Tomography (OCT) image data to generate an indication of how well a retina10of a subject's eye20responds to a flickering light stimulus. The functional OCT data processed by the apparatus100-1is acquired by an OCT imaging device200, specifically by the OCT imaging device200employing an ophthalmic scanner (not shown) to scan an OCT sample beam generated by an OCT measurement module210across a region R of the subject's retina10while the retina10is being repeatedly stimulated by a light stimulus generated by a light stimulus generator220of the OCT imaging device200. The light stimulus may, as in the present example embodiment, comprise a full-field light stimulus (or flash), which provides substantially uniform illumination (at wavelengths in the visible spectrum between about 380 and 740 nm in the present example, although other wavelengths could alternatively or additionally be used) that fills the whole visual field of the subject. The light stimulus generator220may, for example, comprise a light-emitting diode (LED) or other optical emitter for generating the light stimuli. The flashes that the light stimulus generator220emits may, as in the present example embodiment, give rise to a random (or pseudo-random) stimulation of the retina over time. In other words, the light stimulus generator220may emit light flashes that are randomly or pseudo-randomly distributed in time, so that the subject cannot (subconsciously) learn to anticipate upcoming flashes, thereby allowing a more accurate functional response to the subject's retina10to light stimulation to be measured. It should be noted, however, that the light stimulus need not be a full-field stimulus, and may alternatively stimulate only a portion of the retina, which may be illuminated in accordance with a structural scan pattern (e.g. an annulus, a hypotrochoid, or Lissajous figure, for example) by the ophthalmic scanner (not shown) of the OCT imaging device200. As illustrated inFIG.1, the apparatus100-1of the present example embodiment comprises a receiver module110, a correlation calculator module120-1and, optionally, an image data generator module130, which are communicatively coupled (e.g. via a bus140) so as to be capable of exchanging data with one another and with the OCT imaging device200. FIG.2is a schematic illustration of a programmable signal processing hardware300, which may be configured to process functional OCT data using the techniques described herein and, in particular, function as the receiver module110, the correlation calculator module120-1and the (optional) image data generator module130of the first example embodiment. The programmable signal processing hardware300comprises a communication interface (I/F)310for receiving the functional OCT data from the OCT imaging device200, and outputting image data described herein below, which defines an image indicating the response of the retina to the light stimulus. The signal processing apparatus300further comprises a processor (e.g. a Central Processing Unit, CPU, or Graphics Processing Unit, GPU)320, a working memory330(e.g. a random access memory) and an instruction store340storing a computer program345comprising the computer-readable instructions which, when executed by the processor320, cause the processor320to perform various functions including those of the receiver module120-1, the correlation calculator module120-1and/or the image data generator module130described herein. The working memory330stores information used by the processor320during execution of the computer program345, including intermediate processing results such as the calculated products of stimulus indicators and respective windowed portions of the sequence of B-scans, for example. The instruction store340may comprise a ROM (e.g. in the form of an electrically-erasable programmable read-only memory (EEPROM) or flash memory) which is pre-loaded with the computer-readable instructions. Alternatively, the instruction store340may comprise a RAM or similar type of memory, and the computer-readable instructions of the computer program345can be input thereto from a computer program product, such as a non-transitory, computer-readable storage medium350in the form of a CD-ROM, DVD-ROM, etc. or a computer-readable signal360carrying the computer-readable instructions. In any case, the computer program345, when executed by the processor320, causes the processor320to execute a method of processing functional OCT data as described herein. It should be noted, however, that the receiver module110, the correlation calculator module120-1and/or the image data generator module130may alternatively be implemented in non-programmable hardware, such as an application-specific integrated circuit (ASIC). In the present example embodiment, a combination370of the hardware components shown inFIG.2, comprising the processor320, the working memory330and the instruction store340, is configured to perform functions of the receiver module110, the correlation calculator module120-1and the image data generator module130that are described below. FIG.3is a flow diagram illustrating a method performed by the processor320, by which the processor320processes functional OCT data, which has been acquired by the OCT imaging device200scanning the subject's retina10while the retina10is being repeatedly stimulated by the light stimulus, to generate an indication of a response of the retina10to the light stimulus. In step S10ofFIG.3, the receiver module110receives from the OCT imaging device200, as the functional OCT image data: (i) OCT image data that has been generated by the OCT imaging device200repeatedly scanning a scanned region R of the retina10over a time period T; and (ii) stimulus data defining a sequence of s stimulus indicators, each stimulus indicator being indicative of a stimulation of the retina10by the light stimulus in a respective time interval, T/s, of a sequence of time intervals that spans the time period T. The received OCT image data may, as in the present example embodiment, comprise a sequence of b B-scans, which has been generated by the OCT imaging device200repeatedly scanning the scanned region R of the retina10over the time period T.FIG.4illustrates functional OCT image data acquired by the receiver module110in step S10ofFIG.3. As illustrated inFIG.4, each B-scan400in the sequence of B-scans can be represented as a 2D image made up of a A-scans (vertical lines). Each A-scan comprises a one-dimensional array of d pixels, where the pixel value of each pixel represents a corresponding OCT measurement result, and the location of each pixel in the one-dimensional array is indicative of the OCT measurement location in the axial direction of the OCT imaging device200, at which location the corresponding pixel value was measured. The OCT image data can thus be represented as a three-dimensional pixel array500, which is a×b×d pixels in size. It should be noted that each A-scan in the B-scan400may be an average of a number of adjacent A-scans that have been acquired by the OCT imaging device200. In other words, the OCT imaging device200may acquire A-scans having lateral spacing (e.g. along the surface of the retina) which is smaller than the optical resolution of the OCT imaging device200, and average sets of adjacent A-scans to generate a set of averaged A-scans which make up a B-scans displaying improved signal-to-noise. The OCT imaging device200generates the OCT image data by scanning a laser beam across the scanned region R of the retina10in accordance with a predetermined scan pattern, acquiring the A-scans that are to make up each B-scan400as the scan location moves over the scanned region R. The shape of the scan pattern on the retina10is not limited, and is usually determined by a mechanism in the OCT imaging device200that can steer the laser beam generated by the OCT measurement module210. In the present example embodiment, galvanometer (“galvo”) motors, whose rotational position values are recorded, are used to guide the laser beam during the acquisition of the OCT data. These positions can be correlated to locations on the retina10in various ways, which will be familiar to those versed in the art. The scan pattern may, for example, trace out a line, a curve, or a circle on the surface of the retina10, although a lemniscate scan pattern is employed in the present example embodiment. The A-scans acquired during each full period of the scan pattern form one B-scan. In the present example embodiment, all of the b B-scans are recorded in the time period T, such that the time per B-scan is T/b, and the scan pattern frequency is b/T. During the time period T, while the OCT image data is being generated by the OCT imaging device200, a stimulus is shown to the subject, which can be a full-field stimulus (substantially the same brightness value over the whole visual field), as in the present example embodiment, or a spatial pattern, where the visual field is divided into e.g. squares, hexagons or more complicated shapes. In the case of a full-field stimulus, at any point in time, the brightness can be denoted, for example, as either “1” (full brightness) or as “−1” (darkness, with no stimulus having been applied). The time period Tis divided into a sequence of s time intervals (corresponding to the “stimulus positions” referred to herein), each of size Vs and, for each time interval, there is an associated stimulus indicator (s1, s2, s3. . . ) which is indicative of a stimulation of the retina10by the light stimulus in the respective time interval T/s. Thus, each stimulus indicator in the sequence of stimulus indicators may take a value of either 1 or −1 (although the presence or absence of the stimulus may more generally be denoted by n and −n, where n is an integer). The concatenation of the stimulus indicator values that are indicative of the stimulation of the retina10during OCT image data generation is referred to herein as a sequence S of stimulus indicators. One choice for S is an m-sequence, which is a pseudo-random array. In alternative embodiments, in which there is a spatial pattern to the stimulus, each individual field can either display a completely different m-sequence, or a version of one m-sequence that is (circularly) delayed by a specific time, or an inversion of one m-sequence (i.e. when one field shows a 1, another shows a −1 and vice versa). As noted above, the receiver module110is configured to receive stimulus data defining the sequence S of stimulus indicators s1, s2, s3, etc. The receiver module110may, for example, receive information defining the sequence S of stimulus indicators itself, or alternatively information that allows the sequence S of stimulus indicators to be constructed by the apparatus100-1. It should be noted that, although each stimulus indicator in the sequence S of stimulus indicators is indicative of whether or not the retina10was stimulated by the light stimulus in the corresponding time interval of duration T/s, the stimulus indicator is not so limited, and may, in other example embodiments, be indicative of a change in stimulation of the retina10by the light stimulus that occurs in a respective time interval of the sequence S of time intervals that spans the time period T. For example, in the following description of correlation calculations, each windowed portion of the sequence of B-scans may be multiplied by −1 if the stimulus changes from +1 to ˜1 in the associated time interval T/s, by +1 if the stimulus changes from −1 to +1 in the associated time interval T/s, and by zero if the stimulus does not change in the time interval. After at least some of the functional OCT data have been received by the receiver module110, the correlation calculator120-1begins to calculate a rolling window correlation between a sequence of B-scans that is based on the OCT image data and at least some of the stimulus indicators in the sequence S of stimulus indicators. More particularly, the correlation calculator module120-1calculates the rolling window correlation firstly by calculating, in step S20-1ofFIG.3, for each of the stimulus indicators s1, s2, s3, etc., a product of the stimulus indicator and a respective windowed portion of the sequence of B-scans500comprising a predetermined number, blag, of B-scans, beginning with (or otherwise including) a B-scan which is based on a portion of the OCT image data generated while the retina10was being stimulated in accordance with the stimulus indicator. The correlation calculator module120-1thus generates in step S20-1ofFIG.3a plurality of calculated products. It should be noted that the intervals T/b and T/s are not necessarily equal, and that there are b/s B-scans per stimulus position/indicator, or s/b stimuli per B-scan. By way of an example, b/s=2 in the present example embodiment, so that two B-scans are generated by the OCT imaging device200while the retina is being stimulated, or is not being stimulated (as the case may be), in accordance with each stimulus indicator value. Thus, the correlation calculator module120-1calculates a product of the value of the first stimulus indicator s1, which is −1 in the example ofFIG.4, and each of the data elements of a first portion (or block)600-1of the three-dimensional array of pixels500, which portion600-1is a×blag×d pixels in size and includes two B-scans that were generated by the OCT imaging device200while the retina was not being stimulated (in accordance with the stimulus indicator value “−1” applicable for the time interval from time t=0 to t=T/s) and six subsequent B-scans, as blag=8 in the example ofFIG.4(although other values for blagcould alternatively be used). The value of blagis preferably set to correspond to the number of B-scans generated by the OCT imaging device200in a period of no more than about 1 second, as the use of greater values of blagmay make little or no improvement to the calculated retinal response, whilst making the calculation more demanding of computational resources. In other words, the correlation calculator module120-1multiplies each matrix element of a matrix, which is formed by the portion600-1of the three-dimensional array500of pixels that is a×blag×d pixels in size, by the value (“−1”) of the first stimulus indicator, s1, in the sequence S of indicator values defined by the received stimulus data. Then, for the second stimulus indicator, s2, in the sequence S of stimulus indicators (having the value “+1”), each data element of the data elements of a second portion (or block)600-2of the three-dimensional pixel array500, which second portion600-2is also a×blag×d pixels in size but begins with the two B-scans that were generated by the OCT imaging device200while the retina was being stimulated (in accordance with the second stimulus indicator value “+1” applicable for the time interval from time t=T/s to t=2T/s) and also includes six adjacent, subsequent B-scans, by the corresponding stimulus indicator value “+1”. This multiplication process is repeated for the remaining stimulus indicators in the sequence S of stimulus indicators, with the correlation calculator module120-1moving the rolling window forward in time by one time interval T/s in each step of the process, so that it slides past the second stimulus indicator, s1, in the sequence S of stimulus indicators and covers the stimulus indicator immediately adjacent the right-hand boundary of the rolling window as it was previously positioned, and the product of the stimulus indicator and windowed portion of the sequence of B-scans500is calculated once again, using the newly-windowed portion of the sequence S of stimulus indicators and the corresponding B-scans in the sequence of B-scans500to generate another block of eight weighted B-scans. This procedure of sliding the rolling window forward in time and calculating the product to obtain a block of weighted B-scans for each rolling window position is repeated until the rolling window reaches the end of the sequence S of stimulus indicators, thereby generating a plurality of data blocks that are each a×blag×d pixels in size, as illustrated inFIG.4. In step S30ofFIG.3, the correlation calculator module120-1combines the calculated products, thus generating an indication of the response of the retina10to the light stimulus. In the present example embodiment, the correlation calculator module120-1combines the calculated products by performing a matrix addition of the plurality of data blocks600-1,600-2. . . etc. generated in step S20-1, which are each a×blag×d pixels in size, to generate a response block (also referred to herein as a “response volume”)700, which is a three-dimensional array of correlation values that is likewise a×blag×d array elements in size. The correlation values in the response block700may each be divided by s, to obtain a normalised response. As an alternative to the correlation calculation described above (sum of stimulus values multiplied with OCT blocks), it is also possible to use a more advanced normalisation cross-correlation that takes into account mean and standard deviation of the intensities in the sequence of B-scans500and mean and standard deviation of stimulus values in the sequence of stimulus indicators S. Such normalisation cross-correlation may be calculated using the “norm×corr2” function in Matlab™, for example. The three-dimensional array700of correlation values may further be processed by the correlation calculator module120-1, and the results of those further processing operations may be used by the image data generator module130to generate image data defining an image which indicates the response of the retina to the light stimulus for display to a user of the apparatus100-1, so that an assessment of how well the retina responds to stimulation can be made. These optional further processing operations will now be described with reference to the flow diagram inFIG.5. The response volume700may be reduced to a two-dimensional response image for easier visualisation by taking the average in the depth (d) direction, i.e. one value per A-scan per lag time point. Thus, in (optional) step S40ofFIG.5, the correlation calculator module120-1converts the three-dimensional array700of correlation values, which is a×blag×d pixels in size, into a two-dimensional array800of correlation values, which is a×blagpixels in size (as illustrated inFIG.6(a)), by replacing each one-dimensional array of correlation values in the three-dimensional array700, which one-dimensional array has been calculated using A-scans that are identically located in respective B-scans of the sequence500of B-scans, with a single value that is an average of the correlation values in the one-dimensional array. The two-dimensional array800of correlation values indicates the response of the retina10to the light stimulus as a function of location along the scanned region R of the retina10(i.e. as a function of position along the line defining the scan pattern) and time. The image data generator module130may use the two-dimensional array800of correlation values to generate image data defining an image which indicates the response of the retina to the light stimulus as a function of location in the scanned region of the retina and time, where the values of a and blagdetermine the extent of the spatial and temporal variations of the response. However, it may be preferable to pre-process the two-dimensional array800of correlation values generated in step S40prior to image data generation (or prior to the alternative further processing operation described below), in order to accentuate the time-dependent variability of the signal, i.e. the variation of the retinal response to light stimulation over time. Such pre-processing may be desirable in cases where the response variability in the A-scan direction is greater than in the time lag direction. The correlation calculator module120-1may pre-process the two-dimensional array800of correlation values, which comprises a sequence of blagone-dimensional arrays (A1, A2, . . . Ablag), each indicating the response of the retina10to the light stimulus as a function of location in the scanned region R of the retina10, by generating a normalised two-dimensional array of correlation values. The correlation calculator module120-1may, as illustrated inFIG.6(b), generate a normalised two-dimensional array,900-1, of correlation values by subtracting the first one-dimensional array, A1, in the sequence of one-dimensional arrays from each remaining one-dimensional array (A2, A3, . . . , Ablag) in the sequence of one-dimensional arrays. Alternatively, the correlation calculator module120-1may generate a normalised two-dimensional array of correlation values,900-2, by calculating an array of averaged correlation values, A_=1blag⁢∑n=1blagAn, such that each averaged correlation value in the array of averaged correlation values is an average (mean) of the correlation values that are correspondingly located in the sequence of one-dimensional arrays, and subtracting the calculated array of averaged correlation values, Ā, from each of the one-dimensional arrays (A1, A2, A3, . . . , Ablag) in the sequence of one-dimensional arrays (in other words, performing a vector subtraction of the calculated array of averaged correlation values from each of the one-dimensional arrays), as illustrated inFIG.6(c). In both of these alternative ways of calculating normalised two-dimensional array of correlation values, the resulting normalised two-dimensional array of correlation values,900-1or900-2, indicates the response of the retina to the light stimulus as a function of location in the scanned region R of the retina10and time. To allow the response of the retina to the light stimulus to be illustrated in a form that may be more useful for a healthcare practitioner such as an ophthalmologist, the correlation calculator module120-1may, as shown in step S50ofFIG.5, convert the two-dimensional array of correlation values (or the normalised two-dimensional array of correlation values, as the case may be) to a sequence of correlation values by replacing each of the one-dimensional arrays of correlation values in the two-dimensional array800,900-1or900-2(each of the one-dimensional arrays indicating the response of the retina10to the light stimulus as a function of location in the scanned region R of the retina10) with a single respective value that is an average of the correlation values in the one-dimensional array, the sequence of correlation values indicating a response of the scanned region R of the retina10to the light stimulus as a function of time. In step S60ofFIG.5, the image data generator module130uses the sequence of correlation values generated in step S50to generate image data defining an image which indicates the response of the retina10to the light stimulus. The image data may, for example, define an image which indicates the calculated response of the scanned region R of the retina10to the light stimulus as a function of time; in other words, the strength of the correlation of the change in OCT intensity with the time elapsed since the corresponding stimulus was applied. An example of such an image is shown inFIG.7, where the solid response curve illustrates the strength of the calculated correlation of the change in OCT intensity with the time elapsed since the corresponding stimulus was applied. This data may, as also illustrated inFIG.7, be augmented by additional plotted curves (or coloured bands) defining upper and lower limits, which may be created, for example, by computing a confidence interval from functional OCT data recorded from a set of healthy eyes. Diseased eyes would be expected to fall outside of these limits, thereby aiding the healthcare practitioner to diagnose potential loss of function. A typical representation may show a green band for the 95% confidence interval as computed from functional OCT data acquired from a set of healthy eyes. Alternatively, bands or limits may be displayed that have been computed from functional OCT data acquired from eyes with specific diseases. Additionally or alternatively, the image data may define an image which indicates one or more properties of a curve which defines the response of the scanned region R of the retina10to the light stimulus as a function of time, for example the (solid) response curve shown inFIG.7. An indicated property of the response curve may (depending on the shape of the curve) be the presence of a change from a predetermined first value to at least a predetermined second (higher or lower) value, the presence of one or more maxima or minima in the response curve, or the absence of a significant change in the calculated correlation strength indicated by the response curve (e.g. as determined by the calculated correlation strength remaining within predefined upper and lower limits), for example. The latter property, i.e. no change in the response curve (other than any noise that may be present) might be expected to be observed in data from diseased eyes, which show little or no response to light stimulation. The indicated property of the response curve may alternatively be data (referred to herein as a “marker”) which quantifies one or more of the aforementioned features of the response curve. For example, where there is an extremum (a maximum or a minimum) in the response curve, the image defined by the image data may provide an indication of the time to the extremum since the stimulus was applied and/or an indication of the amplitude of the extremum relative to a predefined reference (e.g. zero correlation strength). Where there is a second extremum in the response curve (which may be the same or a different kind of extremum than the first extremum), the image defined by the image data may additionally or alternatively provide an indication of the time to the second extremum since the stimulus was applied and/or an indication of the amplitude of the second extremum relative to the predefined reference, and/or an indication of the difference in amplitude between the first and second extrema, for example. The indication(s) (marker(s)) may be provided in the form of one or more numerical values, or as a classification of each value into one of a number of predefined numerical ranges, for example. Each indication may be augmented, in the image that is defined by the image data, with a comment or a colour to indicate whether it is within a normal (healthy) range, or within an abnormal range of values that is indicative of a diseased state. The image data discussed above represents data that has been aggregated over the whole of each B-scan, and thus over the whole of the scanned region R. As a further alternative, respective correlations may be computed for each of a plurality of different sections of the scanned region R of the retina (with each section comprising a different respective set of A-scans), and these correlations may be mapped to an en-face representation of the retina, either as a diagram or as a retinal image such as a fundus image, a scanning laser ophthalmoscope (SLO) image or an en-face OCT image, for example. In other words, the rolling window correlation described above may be calculated separately for each of two or more sections of the sequence of B-scans500, which are obtained by dividing each B-scan in the sequence of B-scan500in the same way, into two or more sets of adjacent A-scans, and concatenating the resulting corresponding sets of A-scans to obtain the respective sections of the sequence of B-scans500, as illustrated inFIG.8(where the B-scans are divided into three equally-sized sections in the A-scan direction, by way of an illustrative example, although there may more generally be more or fewer sections, which need not have the same number of A-scans). The image data may thus additionally or alternatively define an image which indicates a spatial variation, in the scanned region R of the retina10, of the one or more properties of the response curve mentioned above (for example), the spatial variation being overlaid on an en-face representation of at least a portion the retina which includes the scanned region R. The correlations calculated for the different sections of the scanned region R may be coloured in accordance with any appropriate colour scheme to indicate one or more of the following, for example: (i) the value of one of the markers in each of the sections; (ii) which of a predefined set of intervals the marker in each of the sections belongs to, based on a reference database, e.g. green for a part of the scanned region of the retina that has provided a signal which corresponds to a marker “amplitude of the difference between the first and second peak” whose value is within the 95% confidence interval of a population of healthy eyes; (iii) the percentage of the correlation values on the response curve that adheres to the confidence interval of a reference set of either healthy eyes or eyes with a specific disease; or (iv) aggregate values from the response curve, such as maximum, minimum, mean or median over time, where a darker hue or more red colour is higher than a lighter hue or more blue/green colour, for example. FIG.9is an example illustration of an image indicating respective correlation strengths calculated for each of four different sections, R1, R2, R3, and R4, of the scanned region R of the retina10(using four corresponding sections of the sequence of B-scans500), which are overlaid on a representation1000of the retina10. Where the scan has taken place, different colours and hues may be used to indicate one of options (i) to (iv) listed above, for example. In the example ofFIG.9, the scan pattern on the retina resembles the shape of a figure of 8, although other scan patterns could alternatively be used. The image which indicates the overlay of the spatial variation (in the scanned region R) of the one or more properties of the response curve onto an en-face representation may be turned into an animation by showing how the correlation strength varies over time at each scan location in the scanned region R shown in the image. Colours and hue may be used to represent the amplitude of the correlation strength and sign by converting either the absolute strength or the normalised strength values to different hues, e.g. darker hues to illustrate a stronger signal, and different colours, e.g. blue for positive correlation and red for negative correlation, for example. The image data may define an image which is indicative of retinal responses derived from two separate functional OCT data sets, for example first set of functional OCT data that has been acquired from an eye, and a second set of functional OCT data that has subsequently been acquired from the same eye, the image allowing corresponding responses of the retina to be compared to one another. The image data generator130may generate image data that allows two main forms of results to be displayed, as follows: (i) retinal responses based on the first and second sets of functional OCT data, which may be presented in the same (or same kind of) graph or table in order to enable the healthcare practitioner to see the absolute values ‘side by side’—this is applicable to both the correlation strength variations over time (which may, for example, be plotted on a graph) and the derived markers (which may, for example, be presented in columns or rows of a table); and (ii) the difference or a ratio between the retinal responses based on the first and second sets of functional OCT data. Colour and hue may be used to show the magnitude and sign (e.g. red for negative and blue for positive) of the difference, for example. An example of a functional OCT report defined by such image data is illustrated inFIG.10. Embodiment 2 In the first example embodiment, the correlation calculator module120-1is configured to calculate the rolling window correlation between the sequence of B-scans500and the sequence S of stimulus indicators received from the OCT imaging device200, and to subsequently process the resulting three-dimensional array700of correlation values (in step S40ofFIG.5) so as to generate a two-dimensional array800of correlation values, by taking the average of the correlation values in the depth (d) direction. However, the averaging operation may, as in the present example embodiment, alternatively be performed on the B-scans prior to their correlation with the sequence S of stimulus indicators, thereby simplifying and speeding up the correlation calculation. FIG.11is a schematic illustration of an apparatus100-2according to the second example embodiment, which comprises, in addition to the receiver module110and the image data generator module130that are the same as those in apparatus100-1, a B-scan processing module115and a correlation calculator module120-2. The apparatus100-2of the present example embodiment thus differs from the apparatus100-1of the first example embodiment only by comprising the B-scan processing module115, and the correlation calculator module120-2, whose functionality differs from that of the correlation calculator module120-1of the first example embodiment (as explained in more detail below). The following description of the second example embodiment will therefore focus on these differences, with all other details of the first example embodiment, which are applicable to the second example embodiment, not being repeated here for sake of conciseness. It should be noted that the variations and modifications which may be made to the first example embodiment, as described above, are also applicable to the second embodiment. It should also be noted that one or more of the illustrated components of the apparatus100-2may be implemented in the form of a programmable signal processing hardware as described above with reference toFIG.2, or alternatively in the form of non-programmable hardware, such as an application-specific integrated circuit (ASIC). FIG.12is a flow diagram illustrating a method by which the apparatus100-2of the second example embodiment processes functional OCT data to generate an indication of a response of the retina10to the light stimulus. In step S10ofFIG.12(which is same as step S10inFIG.3), the receiver module110receives from the OCT imaging device200, as the functional OCT image data: (i) OCT image data (specifically, in the form of a sequence of B-scans500) that has been generated by the OCT imaging device200repeatedly scanning the scanned region R of the retina10over a time period T; and (ii) stimulus data defining the sequence of s stimulus indicators, each indicative of a stimulation of the retina by the light stimulus in a respective time interval, T/s, of a sequence of time intervals that spans the time period T. In step S15ofFIG.12, the B-scan processing module115converts the sequence of B-scans500received by the receiver module110in step S10into a sequence of reduced B-scans550, by replacing each A-scan in the sequence of A-scans forming each B-scan400with a respective average value of A-scan elements of the A-scan, as illustrated inFIG.13. In step S20-2ofFIG.12, the correlation calculator module120-2calculates the rolling window correlation between reduced B-scans in the sequence of reduced B-scans550and stimulus indicators s1, s2, s3. . . in the sequence S of stimulus indicators by calculating, for each of the stimulus indicators, a product of the stimulus indicator and a respective windowed portion of the sequence of reduced B-scans550, which may begin with a reduced B-scan that is based on a B-scan of the sequence of B-scans500which has been generated by the OCT imaging device200while the retina10was being stimulated in accordance with the stimulus indicator, and include a predetermined number of subsequent reduced B-scans in the sequence of reduced B-scans550. In step S30ofFIG.12, the correlation calculator module120-2combines the calculated products to generate, as the indication of the response of the retina10to the light stimulus, a two-dimensional array of correlation values (as shown at800inFIG.6(a)) indicating the response of the retina10to the light stimulus as a function of location in the scanned region R of the retina10and time. The two-dimensional array800of correlation values may be processed by the image data generator module130to generate image data in the same way as in the first example embodiment, and/or the correlation calculator module120-2may pre-process the two-dimensional array800of correlation values and/or convert the two-dimensional array of correlation values (or the normalised two-dimensional array of correlation values, as the case may be) to a sequence of correlation values in the same way as the correlation calculator module120-1of the first example embodiment. The sequence of correlation values may further be processed by the image data generator module130to generate image data in the same way as in step S60of the first example embodiment. Embodiment 3 The processing of functional OCT data that is performed by the apparatus100-1of the first example embodiment allows an indication of the functional response of a scanned region R of the retina10to be obtained, based on a correlation which is computed for the whole retinal depth covered by the scan. However, it may be valuable for determining disease diagnosis, for example, to be able to generate an indication of the individual functional responses of one or more retinal layers corresponding to different cell types (e.g. photoreceptors, retinal pigment epithelium, retinal nerve fiber layer, etc.). Such enhanced functionality is provided by the apparatus100-3of the third example embodiment, which will now be described with reference toFIGS.14to16. FIG.14is a schematic illustration of an apparatus100-3for processing functional OCT image data to generate an indication of the individual responses of one or more layers of the retina to the light stimulus, according to the third example embodiment. The apparatus100-3comprises the same receiver module110as the first and second example embodiments, a B-scan processing module117, a correlation calculator module120-3, and an image generator module130which is the same as that of the first and second example embodiments. It should also be noted that one or more of the illustrated components of the apparatus100-3may be implemented in the form of a programmable signal processing hardware as described above with reference toFIG.2, or alternatively in the form of non-programmable hardware, such as an application-specific integrated circuit (ASIC). Processing operations performed by the apparatus100-3will now be described with reference toFIG.15. FIG.15is a flow diagram illustrating a method by which the apparatus100-3of the third example embodiment processes functional OCT data to generate an indication of the response of one or more layers of the retina10to the light stimulus. In step S10ofFIG.15, the receiver module110receives functional OCT image data from the OCT imaging device200. Step S10inFIG.15is the same as step S10inFIG.3, and will therefore not be described in further detail here. In step S12ofFIG.15, the B-scan processing module117identically segments each B-scan400in the sequence of B-scans500into a plurality of B-scan layers, so that each B-scan layer comprises respective sections of the A-scans forming the B-scan400. In other words, as illustrated inFIG.16, the B-scan processing module117divides a first B-scan400-1in the sequence of B-scans500into a plurality of layers (or segments)400-1a,400-1band400-1cin the depth direction, so that each layer comprises a respective set of a A-scan sections, divides a second B-scan400-2in the sequence of B-scans500into a plurality of layers (or segments)400-2a,400-2band400-2cin the depth direction, so that each layer comprises a respective set of a A-scan sections, and so on. It should be noted that the segmentation of the B-scans by the B-scan processing module117into three equal layers inFIG.16is given by way of example only, and that the B-scans may be segmented into a greater or smaller number of B-scan layers. It should also be noted that the number of A-scan elements in the columns of the B-scan layers need not be the same; in other words, the B-scan layers may have different respective thicknesses. The B-scan processing module117further concatenates corresponding B-scan layers (i.e. B-scan layers from different B-scans, which B-scan layers contain respective sets of OCT measurement results derived from the same range of depths from the retinal surface) from the segmented B-scans to generate sequences of concatenated B-scan layers. Thus, as illustrated inFIG.16, the B-scan processing module117concatenates B-scan layers400-1a,400-2a,400-3a, . . . etc. to generate a first sequence of concatenated B-scan layers,450a, which corresponds to a first layer of the retina10, concatenates B-scan layers400-1b,400-2b,400-3b, . . . etc. to generate a second sequence of concatenated B-scan layers,450b, which corresponds to a second (deeper) layer of the retina10, and concatenates B-scan layers400-1c,400-2c,400-3c, . . . etc. to generate a third sequence of concatenated B-scan layers,450c, which corresponds to a third (yet deeper) layer of the retina10. Each of the sequences of concatenated B-scan layers thus forms a three-dimensional array of A-scan elements, which corresponds to a respective layer of the retina10. In step S20-3ofFIG.15, the correlation calculator module120-3calculates, for each of at least one sequence of concatenated B-scan layers of the sequences of concatenated B-scan layers generated in step S12ofFIG.15, a respective rolling window correlation between concatenated B-scan layers in the sequence of concatenated B-scan layers and stimulus indicators (s1, s2, s3) in the sequence S of stimulus indicators, specifically by calculating, for each stimulus indicator, a product of the stimulus indicator and a respective windowed portion of the sequence of concatenated B-scan layers, comprising a B-scan layer of the B-scan layers which is based on a B-scan400which has been generated by the OCT imaging device200while the retina10was being stimulated in accordance with the stimulus indicator, and the predetermined number, blag, of subsequent B-scan layers in the sequence of concatenated B-scan layers. In step S30ofFIG.15, for each of the at least one sequence of concatenated B-scan layers, the correlation calculator module120-3combines the products calculated in step S20-3to generate a respective three-dimensional array of values (“response volume”) that provides an indication of a response of the respective layer of the retina (10) to the light stimulus. Each resulting three-dimensional array of correlation values may further be processed by the correlation calculator module120-3, and the results of those further processing operations may be used by the image data generator module130to generate image data defining an image which indicates the response of the corresponding layer of the retina to the light stimulus for display to a user of the apparatus100-3, using the further processing operations that have been explained in the above description of the first embodiment, with reference toFIG.5. More particularly, the response volume corresponding to each retinal layer may be reduced to a two-dimensional response image for easier visualisation, by taking the average in the depth (d) direction, i.e. one value per A-scan per lag time point. Thus, the correlation calculator module120-3may convert each three-dimensional array of correlation values, which is a/3×blag×d pixels in size in the present example embodiment, into a respective two-dimensional array of correlation values, which is a/3×blagpixels in size, by replacing each one-dimensional array of correlation values in the three-dimensional array, which one-dimensional array has been calculated using sections of A-scans that are identically located in respective B-scans of the sequence of B-scans, with a single value that is an average of the correlation values in the one-dimensional array. Thus, each array element of the one-dimensional array is calculated on the basis of a corresponding element of an A-scan. The two-dimensional array of correlation values indicates the response of the corresponding layer of the retina10to the light stimulus as a function of location along the scanned region R of the retina10(i.e. as a function of position along the line defining the scan pattern) and time. The image data generator module130may use at least one of the two-dimensional arrays of correlation values to generate image data defining an image which indicates the response, to the light stimulus, of a respective layer of the retina10corresponding to each of the at least one of the two-dimensional arrays as a function of location in the scanned region R of the retina10and time. However, it may be preferable to pre-process at least some of the two-dimensional arrays of correlation values prior to image data generation (or prior to the alternative further processing operation described below), in order to accentuate the time-dependent variability of the signal, i.e. the variation of the retinal layer response to light stimulation over time. Such pre-processing may be desirable in cases where the response variability in the A-scan direction is greater than in the time lag direction. The correlation calculator module120-3may pre-process one or more of the two-dimensional arrays of correlation values, each comprising a sequence of blagone-dimensional arrays, each indicating the response of the corresponding layer of the retina to the light stimulus as a function of location in the scanned region R of the retina10, to generate a normalised two-dimensional array of correlation values. The correlation calculator module120-3may generate the normalised two-dimensional array of correlation values by subtracting the first one-dimensional array in the sequence of one-dimensional arrays from each remaining one-dimensional array in the sequence of one-dimensional arrays. Alternatively, the correlation calculator module120-3may generate a normalised two-dimensional array of correlation values by calculating an array of averaged correlation values, such that each averaged correlation value in the array of averaged correlation values is an average (mean) of the correlation values that are correspondingly located in the sequence of one-dimensional arrays, and subtracting the calculated array of averaged correlation values from each of the one-dimensional arrays in the sequence of one-dimensional arrays (in other words, performing a vector subtraction of the calculated array of averaged correlation values from each of the one-dimensional arrays). In both of these alternative ways of calculating normalised two-dimensional array of correlation values, the resulting normalised two-dimensional array of correlation values indicates the response of the corresponding layer of the retina to the light stimulus as a function of location in the scanned region R of the retina10and time. The image data generator module130may use each normalised two-dimensional array of correlation values to generate image data defining an image that indicates the response of the corresponding layer of the retina10to the light stimulus as a function of location in the scanned region R of the retina10and time. To allow the response of one or more layers of the retina10to the light stimulus to be illustrated in a form that may be more useful for a healthcare practitioner or other user, the correlation calculator module120-3may convert the two-dimensional array of correlation values (or the normalised two-dimensional array of correlation values, as the case may be) corresponding to each of one or more of the retinal layers to a sequence of correlation values by replacing each of the one-dimensional arrays of correlation values in the two-dimensional array (each of the one-dimensional arrays indicating the response of the corresponding layer of the retina10to the light stimulus as a function of location along the scanned region R of the retina10) with a single respective value that is an average of the correlation values in the one-dimensional array, each sequence of correlation values indicating a response of the respective layer of the retina10in the scanned region R to the light stimulus as a function of time. The image data generator module130may use one or more of the sequences of correlation values to generate image data defining an image that indicates the response of the respective one or more layers of the retina10in the scanned region R of the retina to the light stimulus. Similar to the first and second example embodiments described above, the image data generator module130may use one or more sequences of correlation values to generate an image which indicates at least one of: the response of the respective one or more layers of the retina10in the scanned region R to the light stimulus as a function of time; one or more properties of a respective one or more curves defining the response of the respective one or more layers of the retina10in the scanned region R to the light stimulus as a function of time; and a spatial variation, in the scanned region R of the retina10, of one or more properties of the respective one or more curves defining the response of the respective one or more layers of the retina10in the scanned region R to the light stimulus as a function of time, the spatial variation being overlaid on an en-face representation of at least a portion the retina10which includes the scanned region R. Embodiment 4 In the third example embodiment, the correlation calculator module120-3is, in one configuration, configured to calculate, for each of at least one sequence of concatenated B-scan layers of the concatenated sequences of B-scan layers, a respective rolling window correlation between the sequence of concatenated B-scan layers and the sequence S of stimulus indicators received from the OCT imaging device200, and to subsequently process the resulting three-dimensional array of correlation values so as to generate a two-dimensional array of correlation values, by taking an average of the correlation values in the depth (d) direction. However, the averaging operation may, as in the present example embodiment, alternatively be performed on the one or more of the sequences of concatenated B-scan layers prior to their correlation with the sequence S of stimulus indicators, thereby simplifying and speeding up the correlation calculation. FIG.17is a schematic illustration of an apparatus100-4according to the fourth example embodiment, which comprises, in addition to the receiver module110and the image data generator module130that are the same as those in apparatuses100-1,100-2and100-3of the foregoing example embodiments, a B-scan processing module118and a correlation calculator module120-4, which are described in detail below. The B-scan processing module118has functionality in common with that the B-scan processing module117of the third example embodiment (which will not be described here again), as well as some further functionality which is described below. It should also be noted that one or more of the illustrated components of the apparatus100-4may be implemented in the form of a programmable signal processing hardware as described above with reference toFIG.2, or alternatively in the form of non-programmable hardware, such as an application-specific integrated circuit (ASIC). FIG.18is a flow diagram illustrating a method by which the apparatus100-4of the fourth example embodiment processes functional OCT data to generate an indication of a response of the retina10to the light stimulus. In step S10ofFIG.18, the receiver module110receives the functional OCT image data from the OCT imaging device200. Step S10inFIG.18is the same as step S10inFIG.3, and will therefore not be described in further detail here. In step S12ofFIG.18, the B-scan processing module118identically segments each B-scan400in the sequence of B-scans500into a plurality of B-scan layers, so that each B-scan layer comprises respective sections of the A-scans forming the B-scan400. Step S12inFIG.18is the same as step S12inFIG.15, and will therefore not be described in further detail here. As in the third example embodiment, each of the sequences of concatenated B-scan layers forms a three-dimensional array of A-scan elements, which corresponds to a respective later of the retina10. In step S17ofFIG.18, the B-scan processing module118converts each of at least one of the sequences of concatenated B-scan layers into a respective sequence of concatenated reduced B-scan layers, by replacing, for each B-scan layer in each of the at least one sequence of concatenated B-scan layers, the sections of the A-scans forming the B-scan layer with corresponding values of an average of A-scan elements in the sections of the A-scans. For example, in the illustrative example ofFIG.16, the B-scan processing module118converts the three-dimensional array formed by the first sequence of concatenated B-scan layers,450a, into a two-dimensional array, by replacing the first column of B-scan layer (or segment)400-1a, comprising A-scan elements a1and a2, with a single value that is an average of a1and a2, with the remaining columns of B-scan segment400-1a, and the other B-scan segments400-1b,400-1c, etc. of the first sequence of concatenated B-scan layers450aare processed in the same way. The B-scan processing module118may likewise process the second sequence of concatenated B-scan layers450band/or the third sequence of concatenated B-scan layers450cin addition to, or alternatively to, the first sequence of concatenated B-scan layers450a. Thus, the B-scan processing module118can convert each of one or more of the three-dimensional arrays of OCT measurement values shown in the example ofFIG.16, each of which is a/3×blag×d pixels in size, into a respective two-dimensional array of values, which is a/3×blagpixels in size. In step S20-4ofFIG.18, the correlation calculator module120-4calculates, for each of at least one sequence of concatenated reduced B-scan layers of the sequences of concatenated reduced B-scan layers generated in step S17ofFIG.18, a respective rolling window correlation between reduced B-scan layers in the sequence of concatenated reduced B-scan layers and stimulus indicators (s1, s2, s3) in the sequence S of stimulus indicators, specifically by calculating, for each stimulus indicator, a product of the stimulus indicator and a respective windowed portion of the sequence of concatenated reduced B-scan layers comprising a reduced B-scan layer which is based on a B-scan that has been generated by the OCT imaging device200while the retina10was being stimulated in accordance with the stimulus indicator, and the predetermined number, blag, of subsequent reduced B-scan layers in the sequence of concatenated reduced B-scan layers. In step S30ofFIG.18, for each of the at least one sequence of concatenated reduced B-scan layers, the correlation calculator module120-4combines the products calculated in step S20-4to generate a respective two-dimensional array of values (“response area”) that provides an indication of a response of a layer of the retina corresponding to the sequence of concatenated reduced B-scan layers to the light stimulus as a function of location in the scanned region R of the retina10and time. Each resulting two-dimensional array of correlation values may further be processed by the correlation calculator module120-4in the same way as the two-dimensional array(s) of correlation values is/are processed by the correlation calculator module120-3in the third example embodiment described above. Thus, the image data generator module130may use at least one of the two-dimensional arrays of correlation values to generate image data defining an image which indicates the response, to the light stimulus, of a respective layer of the retina10corresponding to each of the at least one of the two-dimensional arrays as a function of location in the scanned region R of the retina10and time. However, it may be preferable to pre-process at least some of the two-dimensional arrays of correlation values prior to image data generation (or prior to the alternative further processing operation described below), in order to accentuate the time-dependent variability of the signal, i.e. the variation of the retinal layer response to light stimulation over time. Such pre-processing may be desirable in cases where the response variability in the A-scan direction is greater than in the time lag direction. The correlation calculator module120-4may pre-process one or more of the two-dimensional arrays of correlation values, each comprising a sequence of blagone-dimensional arrays, each array indicating the response of the corresponding layer of the retina10to the light stimulus as a function of location in the scanned region R of the retina10, to generate a normalised two-dimensional array of correlation values. The correlation calculator module120-4may generate a normalised two-dimensional array of correlation values (indicating the response of the corresponding layer of the retina10to the light stimulus as a function of location in the scanned region R of the retina10and time) using one of the processes described in the third example embodiment, for example. The image data generator module130may use each normalised two-dimensional array of correlation values to generate image data defining an image that indicates the response of the corresponding layer of the retina10to the light stimulus as a function of location in the scanned region R of the retina10and time. To allow the response of one or more layers of the retina to the light stimulus to be illustrated in a form that may be more useful for a healthcare practitioner such as an ophthalmologist, the correlation calculator module120-4may convert the two-dimensional array of correlation values (or the normalised two-dimensional array of correlation values, as the case may be) corresponding to each of one or more of the retinal layers to a sequence of correlation values by replacing each of the one-dimensional arrays of correlation values in the two-dimensional array (each of the one-dimensional arrays indicating the response of the corresponding layer of the retina10to the light stimulus as a function of location in the scanned region R of the retina10) with a single respective value that is an average of the correlation values in the one-dimensional array, each sequence of correlation values indicating a response of the respective layer of the retina10in the scanned region to the light stimulus as a function of time. The image data generator module130may use one or more of the sequences of correlation values to generate image data defining an image that indicates the response of the respective one or more layers of the retina10in the scanned region R of the retina to the light stimulus. Similar to the third example embodiment described above, the image data generator module130may use one or more sequences of correlation values to generate an image which indicates at least one of: the response of the respective one or more layers of the retina10in the scanned region R to the light stimulus as a function of time; one or more properties of a respective one or more curves defining the response of the respective one or more layers of the retina10in the scanned region R to the light stimulus as a function of time; and a spatial variation, in the scanned region R of the retina10, of one or more properties of the respective one or more curves defining the response of the respective one or more layers of the retina10in the scanned region R to the light stimulus as a function of time, the spatial variation being overlaid on an en-face representation of at least a portion the retina10which includes the scanned region R. Embodiment 5 FIG.19is a schematic illustration of an apparatus100-5according to a fifth example embodiment, which is configured to process functional OCT image data to generate an indication of how well a retina10of a subject's eye20responds to a flickering light stimulus. The functional OCT data processed by the apparatus100-5is acquired by the OCT imaging device200, which has already been described above. The light stimulus may, as in the present example embodiment, comprise a full-field light stimulus (or flash), which provides substantially uniform illumination (at wavelengths in the visible spectrum between about 380 and 740 nm in the present example, although other wavelengths could alternatively or additionally be used) that fills the whole visual field of the subject. The light stimulus generator220may, for example, comprise a light-emitting diode (LED) or other optical emitter for generating the light stimuli. The flashes that the light stimulus generator220emits may, as in the present example embodiment, give rise to a random (or pseudo-random) stimulation of the retina over time. In other words, the light stimulus generator220may emit light flashes that are randomly or pseudo-randomly distributed in time, so that the subject cannot (subconsciously) learn to anticipate upcoming flashes, thereby allowing a more accurate functional response to the subject's retina10to light stimulation to be measured. It should be noted, however, that the light stimulus need not be a full-field stimulus, and may alternatively stimulate only a portion of the retina, which may be illuminated in accordance with a structural scan pattern (e.g. an annulus, a hypotrochoid, or Lissajous figure, for example) by the ophthalmic scanner of the OCT imaging device200. As illustrated inFIG.19, the apparatus100-5of the present example embodiment comprises a receiver module110, a correlation calculator module120-5, a response generator module125-5and, optionally, an image data generator module130, which are communicatively coupled (e.g. via a bus140) so as to be capable of exchanging data with one another and with the OCT imaging device200. The receiver module110and the image data generator module130are the same as those in the first example embodiment. As with the preceding example embodiments, the programmable signal processing hardware300described above with reference toFIG.2may be configured to process functional OCT data using the techniques described herein and, in particular, function as the receiver module110, the correlation calculator module120-5, the response generator module125-5and the (optional) image data generator module130of the fifth example embodiment. It should be noted, however, that the receiver module110, the correlation calculator module120-5, the response generator module125-5and/or the image data generator module130may alternatively be implemented in non-programmable hardware, such as an application-specific integrated circuit (ASIC). In the present example embodiment, a combination370of the hardware components shown inFIG.2, comprising the processor320, the working memory330and the instruction store340, is configured to perform functions of the receiver module110, the correlation calculator module120-5, the response generator module125-5and the image data generator module130that are described below. FIG.20is a flow diagram illustrating a method performed by the processor320, by which the processor320processes functional OCT data, which has been acquired by the OCT imaging device200scanning the subject's retina10while the retina10is being repeatedly stimulated by the light stimulus, to generate an indication of a response of the retina10to the light stimulus. In step S10ofFIG.20, the receiver module110receives from the OCT imaging device200, as the functional OCT image data: (i) OCT image data that has been generated by the OCT imaging device200repeatedly scanning a scanned region R of the retina10over a time period T; and (ii) stimulus data defining a sequence of s stimulus indicators, each stimulus indicator being indicative of a stimulation of the retina10by the light stimulus in a respective time interval, T/s, of a sequence of time intervals that spans the time period T. The received OCT image data may, as in the present example embodiment, comprise a sequence of b B-scans, which has been generated by the OCT imaging device200repeatedly scanning the scanned region R of the retina10over the time period T. Referring back toFIG.4, this figure illustrates functional OCT image data acquired by the receiver module110in step S10ofFIG.20. As illustrated inFIG.4, each B-scan400in the sequence of B-scans can be represented as a 2D image made up of a A-scans (vertical lines). Each A-scan comprises a one-dimensional array of d pixels, where the pixel value of each pixel represents a corresponding OCT measurement result, and the location of each pixel in the one-dimensional array is indicative of the OCT measurement location in the axial direction of the OCT imaging device200, at which location the corresponding pixel value was measured. The OCT image data can thus be represented as a three-dimensional pixel array500, which is a×b×d pixels in size. It should be noted that each A-scan in the B-scan400may be an average of a number of adjacent A-scans that have been acquired by the OCT imaging device200. In other words, the OCT imaging device200may acquire A-scans having lateral spacing (e.g. along the surface of the retina) which is smaller than the optical resolution of the OCT imaging device200, and average sets of adjacent A-scans to generate a set of averaged A-scans which make up a B-scans displaying improved signal-to-noise. The OCT imaging device200generates the OCT image data by scanning a laser beam across the scanned region R of the retina10in accordance with a predetermined scan pattern, acquiring the A-scans that are to make up each B-scan400as the scan location moves over the scanned region R. The shape of the scan pattern on the retina10is not limited, and is usually determined by a mechanism in the OCT imaging device200that can steer the laser beam generated by the OCT measurement module210. In the present example embodiment, galvanometer (“galvo”) motors, whose rotational position values are recorded, are used to guide the laser beam during the acquisition of the OCT data. These positions can be correlated to locations on the retina10in various ways, which will be familiar to those versed in the art. The scan pattern may, for example, trace out a line, a curve, or a circle on the surface of the retina10, although a lemniscate scan pattern is employed in the present example embodiment. The A-scans acquired during each full period of the scan pattern form one B-scan. In the present example embodiment, all of the b B-scans are recorded in the time period T, such that the time per B-scan is T/b, and the scan pattern frequency is b/T. During the time period T, while the OCT image data is being generated by the OCT imaging device200, a stimulus is shown to the subject, which can be a full-field stimulus (substantially the same brightness value over the whole visual field), as in the present example embodiment, or a spatial pattern, where the visual field is divided into e.g. squares, hexagons or more complicated shapes. In the case of a full-field stimulus, at any point in time, the brightness can be denoted, for example, as either “1” (full brightness) or as “−1” (darkness, with no stimulus having been applied). The time period Tis divided into a sequence of s time intervals (corresponding to the “stimulus positions” referred to herein), each of size T/s and, for each time interval, there is an associated stimulus indicator (s1, s2, s3. . . ) which is indicative of a stimulation of the retina10by the light stimulus in the respective time interval T/s. Thus, each stimulus indicator in the sequence of stimulus indicators may take a value of either 1 or −1 (although the presence or absence of the stimulus may more generally be denoted by n and −n, where n is an integer). The concatenation of the stimulus indicator values that are indicative of the stimulation of the retina10during OCT image data generation is referred to herein as a sequence S of stimulus indicators. One choice for S is an m-sequence, which is a pseudo-random array. In alternative embodiments, in which there is a spatial pattern to the stimulus, each individual field can either display a completely different m-sequence, or a version of one m-sequence that is (circularly) delayed by a specific time, or an inversion of one m-sequence (i.e. when one field shows a 1, another shows a −1 and vice versa). As noted above, the receiver module110is configured to receive stimulus data defining the sequence S of stimulus indicators s1, s2, s3, etc. The receiver module110may, for example, receive information defining the sequence S of stimulus indicators itself, or alternatively information that allows the sequence S of stimulus indicators to be constructed by the apparatus100-5. It should be noted that, although each stimulus indicator in the sequence S of stimulus indicators is indicative of whether or not the retina10was stimulated by the light stimulus in the corresponding time interval of duration T/s, the stimulus indicator is not so limited, and may, in other example embodiments, be indicative of a change in stimulation of the retina10by the light stimulus that occurs in a respective time interval of the sequence S of time intervals that spans the time period T. For example, in the following description of correlation calculations, each windowed portion of the sequence of B-scans may be multiplied by −1 if the stimulus changes from +1 to −1 in the associated time interval T/s, by +1 if the stimulus changes from −1 to +1 in the associated time interval T/s, and by zero if the stimulus does not change in the time interval. After at least some of the functional OCT data have been received by the receiver module110, the correlation calculator120-5begins to calculate a rolling window correlation between a sequence of B-scans that is based on the OCT image data and at least some of the stimulus indicators in the sequence S of stimulus indicators. More particularly, the correlation calculator module120-5calculates the rolling window correlation by calculating, in step S20-5ofFIG.20, for each of the stimulus indicators s1, s2, s3, etc., a respective correlation between stimulus indicators in a window comprising the stimulus indicator and a predetermined number of adjacent stimulus indicators, and B-scans of the sequence of B-scans500that are based on a portion of the OCT image data generated while the retina10was being stimulated in accordance with the stimulus indicators in the window. By way of an example, the correlation calculator module120-5of the present example embodiment calculates, for each of the stimulus indicators, a correlation between stimulus indicators in a windowed portion of the sequence S consisting of a stimulus indicator located at a predetermined sequence position in the windowed portion (e.g. the first stimulus indicator in the windowed portion), and a predetermined number of adjacent (e.g. subsequent) stimulus indicators, and corresponding B-scans of the sequence of B-scans500that are based on a portion of the OCT image data generated while the retina10was being stimulated in accordance with the stimulus indicators in the window. As noted above, the intervals T/b and T/s are not necessarily equal, and there are b/s B-scans per stimulus position/indicator, or s/b stimuli per B-scan. By way of an example, b/s=2 in the present example embodiment, so that two B-scans are generated by the OCT imaging device200while the retina10is being stimulated, or is not being stimulated (as the case may be), in accordance with each stimulus indicator value. FIG.21is a schematic illustration of functional OCT image data acquired by the receiver module110in step S10ofFIG.20, and results of processing the functional OCT image data in the fifth example embodiment herein. As illustrated inFIG.21, the correlation calculator module120-5calculates a product of the value of the first stimulus indicator s1in the first windowed portion of stimulus indicators (the first windowed portion further comprising stimulus indicators s2, s3and s4), which is −1 in the example ofFIG.21, and each of the data elements in the first two B-scans of a first portion (or block) of the three-dimensional array of pixels500, which portion is a×2×d pixels in size, the first two B-scans having been generated by the OCT imaging device200while the retina10was not being stimulated, in accordance with the stimulus indicator (s1) value “−1” applicable for the time interval from time t=0 to t=T/s. The correlation calculator module120-5also calculates a product of the value of the second stimulus indicator s2in the first windowed portion of stimulus indicators, which is +1 in the example ofFIG.21, and each of the data elements in the second pair of B-scans of the first portion of the three-dimensional array of pixels500, the second pair of B-scans having been generated by the OCT imaging device200while the retina10was being stimulated, in accordance with the stimulus indicator (s2) value “+1” applicable for the time interval from time t=T/s to t=2T/s. The correlation calculator module120-5similarly calculates a product of the value of the third stimulus indicator s3in the first windowed portion of stimulus indicators, which is also +1 in the example ofFIG.21, and each of the data elements in the third pair of B-scans of the first portion of the three-dimensional array of pixels500, the third pair of B-scans having been generated by the OCT imaging device200while the retina10was being stimulated, in accordance with the stimulus indicator (s3) value “+1” applicable for the time interval from time t=2T/s to t=3T/s. Likewise, the correlation calculator module120-5calculates a product of the value of the fourth stimulus indicator s4in the first windowed portion of stimulus indicators, which is −1 in the example ofFIG.21, and each of the data elements in the fourth pair of B-scans of the first portion of the three-dimensional array of pixels500, the fourth pair of B-scans having been generated by the OCT imaging device200while the retina10was not being stimulated, in accordance with the stimulus indicator (s4) value “−1” applicable for the time interval from time t=3T/s to t=4T/s. The number of stimulus indicators in the window is, of course, not limited to four, and is preferably chosen so that the corresponding number of B-scans, blag, generated by the OCT imaging device200corresponds to a period of no more than about 1 second, as the use of greater values of blagmay make little or no improvement to the calculated retinal response, whilst making the calculation more demanding of computational resources. The result of multiplying each stimulus indicator in the window with respective B-scans in the sequence of B-scans is represented by partial response block600′-1illustrated inFIG.21. This multiplication process is repeated for the remaining stimulus indicators in the sequence S of stimulus indicators, with the correlation calculator module120-5moving the rolling window forward in time by one time interval T/s in each step of the process, so that it slides past the second stimulus indicator, s1, in the sequence S of stimulus indicators and covers the stimulus indicator immediately adjacent the right-hand boundary of the rolling window as it was previously positioned, and the product of the stimulus indicators and respective B-scans in the sequence of B-scans500is calculated once again to generate another partial response block (600′-2, etc.) of weighted B-scans. This procedure of sliding the rolling window forward in time and calculating the product to obtain a block of weighted B-scans for each rolling window position is repeated until the rolling window reaches the end of the sequence S of stimulus indicators, thereby generating a plurality of partial response blocks that are each a×blag×d pixels in size, as illustrated inFIG.21. In step S30-5ofFIG.20, the response generator module125-5generates an indication of the response of the retina10to the light stimulus by combining the calculated correlations. In the present example embodiment, the response generator module125-5combines the calculated correlations by performing a matrix addition of the plurality of partial response data blocks600′-1,600′-2. . . etc. generated in step S20-5, which are each a×blag×d pixels in size, to generate a response block (also referred to herein as a “response volume”)700′, which is a three-dimensional array of combined correlation values that is likewise a×blag×d array elements in size. The combined correlation values in the response block700′ may each be divided by s, to obtain a normalised response. The three-dimensional array700′ of combined correlation values may further be processed by the response generator module125-5, and the results of those further processing operations may be used by the image data generator module130to generate image data defining an image which indicates the response of the retina10to the light stimulus for display to a user of the apparatus100-5, so that an assessment of how well the retina responds to stimulation can be made. These optional further processing operations will now be described with reference to the flow diagram inFIG.22. The response volume700′ may be converted into a two-dimensional response image for easier visualisation by taking the average in the depth (d) direction, i.e. one value per A-scan per lag time point. Thus, in (optional) step S40-5ofFIG.22the response generator module125-5converts the three-dimensional array700′ of combined correlation values, which is a×blag×d pixels in size, into a two-dimensional array800′ of correlation values, which is a×blagpixels in size (as illustrated inFIG.23(a)), by replacing each one-dimensional array of combined correlation values in the three-dimensional array700′, which one-dimensional array has been calculated using A-scans that are identically located in respective B-scans of the sequence500of B-scans, with a single value that is an average of the combined correlation values in the one-dimensional array. The two-dimensional array800′ of combined correlation values indicates the response of the retina10to the light stimulus as a function of location along the scanned region R of the retina10(i.e. as a function of position along the line defining the scan pattern) and time. The image data generator module130may use the two-dimensional array800′ of combined correlation values to generate image data defining an image which indicates the response of the retina10to the light stimulus as a function of location in the scanned region R of the retina10and time, where the values of a and blagdetermine the extent of the spatial and temporal variations of the response. However, it may be preferable to pre-process the two-dimensional array800′ of combined correlation values generated in step S40-5prior to image data generation (or prior to the alternative further processing operation described below), in order to accentuate the time-dependent variability of the signal, i.e. the variation of the retinal response to light stimulation over time. Such pre-processing may be desirable in cases where the response variability in the A-scan direction is greater than in the time lag direction. The response generator module125-5may pre-process the two-dimensional array800′ of combined correlation values, which comprises a sequence of blagone-dimensional arrays (A1, A2, . . . Ablag), each indicating the response of the retina10to the light stimulus as a function of location in the scanned region R of the retina10, by generating a normalised two-dimensional array of combined correlation values. The response generator module125-5may, as illustrated inFIG.23(b), generate a normalised two-dimensional array,900′-1, of correlation values by subtracting the first one-dimensional array, A1, in the sequence of one-dimensional arrays from each remaining one-dimensional array (A2, A3, . . . , Ablag) in the sequence of one-dimensional arrays. Alternatively, the response generator module125-5may generate a normalised two-dimensional array of correlation values,900′-2, by calculating an array of averaged combined correlation values, A_=1blag⁢∑n=1blagAn, such that each averaged combined correlation value in the array of averaged combined correlation values is an average (mean) of the combined correlation values that are correspondingly located in the sequence of one-dimensional arrays, and subtracting the calculated array of averaged combined correlation values, Ā, from each of the one-dimensional arrays (A1, A2, A3, . . . , Ablag) in the sequence of one-dimensional arrays (in other words, performing a vector subtraction of the calculated array of averaged correlation values from each of the one-dimensional arrays), as illustrated inFIG.23(c). In both of these alternative ways of calculating normalised two-dimensional array of combined correlation values, the resulting normalised two-dimensional array of combined correlation values,900′-1or900′-2, indicates the response of the retina10to the light stimulus as a function of location in the scanned region R of the retina10and time. To allow the response of the retina10to the light stimulus to be illustrated in a form that may be more useful for a healthcare practitioner such as an ophthalmologist, the response generator module125-5may, as shown in step S50-5ofFIG.22, convert the two-dimensional array of combined correlation values (or the normalised two-dimensional array of combined correlation values, as the case may be) to a sequence of combined correlation values by replacing each of the one-dimensional arrays of combined correlation values in the two-dimensional array800′,900′-1or900′-2(each of the one-dimensional arrays indicating the response of the retina10to the light stimulus as a function of location in the scanned region R of the retina10) with a single respective value that is an average of the combined correlation values in the one-dimensional array, the sequence of combined correlation values indicating a response of the scanned region R of the retina10to the light stimulus as a function of time. In step S60ofFIG.22, the image data generator module130uses the sequence of combined correlation values generated in step S50-5to generate image data defining an image which indicates the response of the retina10to the light stimulus. The image data may, for example, define an image which indicates the calculated response of the scanned region R of the retina10to the light stimulus as a function of time; in other words, the strength of the correlation of the change in OCT intensity with the time elapsed since the corresponding stimulus was applied. An example of such an image has been described above with reference toFIG.7, and its description will not be repeated here. Additionally or alternatively, the image data may define an image which indicates one or more properties of a curve which defines the response of the scanned region R of the retina10to the light stimulus as a function of time, for example the (solid) response curve shown inFIG.7. An indicated property of the response curve may (depending on the shape of the curve) be the presence of a change from a predetermined first value to at least a predetermined second (higher or lower) value, the presence of one or more maxima or minima in the response curve, or the absence of a significant change in the calculated correlation strength indicated by the response curve (e.g. as determined by the calculated correlation strength remaining within predefined upper and lower limits), for example. The latter property, i.e. no change in the response curve (other than any noise that may be present) might be expected to be observed in data from diseased eyes, which show little or no response to light stimulation. The indicated property of the response curve may alternatively be data (referred to herein as a “marker”) which quantifies one or more of the aforementioned features of the response curve. For example, where there is an extremum (a maximum or a minimum) in the response curve, the image defined by the image data may provide an indication of the time to the extremum since the stimulus was applied and/or an indication of the amplitude of the extremum relative to a predefined reference (e.g. zero correlation strength). Where there is a second extremum in the response curve (which may be the same or a different kind of extremum than the first extremum), the image defined by the image data may additionally or alternatively provide an indication of the time to the second extremum since the stimulus was applied and/or an indication of the amplitude of the second extremum relative to the predefined reference, and/or an indication of the difference in amplitude between the first and second extrema, for example. The indication(s) (marker(s)) may be provided in the form of one or more numerical values, or as a classification of each value into one of a number of predefined numerical ranges, for example. Each indication may be augmented, in the image that is defined by the image data, with a comment or a colour to indicate whether it is within a normal (healthy) range, or within an abnormal range of values that is indicative of a diseased state. The image data discussed above represents data that has been aggregated over the whole of each B-scan, and thus over the whole of the scanned region R. As a further alternative, respective correlations may be computed for each of a plurality of different sections of the scanned region R of the retina (with each section comprising a different respective set of A-scans), and these correlations may be mapped to an en-face representation of the retina, either as a diagram or as a retinal image such as a fundus image, a scanning laser ophthalmoscope (SLO) image or an en-face OCT image, for example. In other words, the rolling window correlation described above may be calculated separately for each of two or more sections of the sequence of B-scans500, which are obtained by dividing each B-scan in the sequence of B-scans500in the same way, into two or more sets of adjacent A-scans, and concatenating the resulting corresponding sets of A-scans to obtain the respective sections of the sequence of B-scans500, as illustrated inFIG.8(where the B-scans are divided into three equally-sized sections in the A-scan direction, by way of an illustrative example, although there may more generally be more or fewer sections, which need not have the same number of A-scans). The image data may thus additionally or alternatively define an image which indicates a spatial variation, in the scanned region R of the retina10, of the one or more properties of the response curve mentioned above (for example), the spatial variation being overlaid on an en-face representation of at least a portion the retina which includes the scanned region R. The correlations calculated for the different sections of the of the scanned region R may be coloured in accordance with any appropriate colour scheme to indicate at least one the following, for example: (i) the value of one of the markers in each of the sections; (ii) which of a predefined set of intervals the marker in each of the sections belongs to, based on a reference database, e.g. green for a part of the scanned region of the retina that has provided a signal which corresponds to a marker “amplitude of the difference between the first and second peak” whose value is within the 95% confidence interval of a population of healthy eyes; (iii) the percentage of the correlation values on the response curve that adheres to the confidence interval of a reference set of either healthy eyes or eyes with a specific disease; or (iv) aggregate values from the response curve, such as maximum, minimum, mean or median over time, where a darker hue or more red colour is higher than a lighter hue or more blue/green colour, for example. As described above,FIG.9illustrates respective correlation strengths calculated using the correlation calculation technique of the first example embodiment for each of four different sections, R1, R2, R3, and R4, of the scanned region R of the retina10(using four corresponding sections of the sequence of B-scans500), which are overlaid on a representation1000of the retina10. The similar figure may be generated using the correlation calculation technique of the present example embodiment. Where the scan has taken place, different colours and hues may be used to indicate one of options (i) to (iv) listed above, for example. In the example ofFIG.9, the scan pattern on the retina resembles the shape of a figure of 8, although other scan patterns could alternatively be used. As with the first example embodiment, the image which indicates the overlay of the spatial variation (in the scanned region R) of the one or more properties of the response curve onto an en-face representation may be turned into an animation by showing how the correlation strength varies over time at each scan location in the scanned region R shown in the image. Colours and hue may be used to represent the amplitude of the correlation strength and sign by converting either the absolute strength or the normalised strength values to different hues, e.g. darker hues to illustrate a stronger signal, and different colours, e.g. blue for positive correlation and red for negative correlation, for example. The image data may define an image which is indicative of retinal responses derived from two separate functional OCT data sets, for example a first set of functional OCT data that has been acquired from an eye, and a second set of functional OCT data that has subsequently been acquired from the same eye, the image allowing corresponding responses of the retina to be compared to one another. The image data generator130may generate image data that allows two main forms of results to be displayed, as follows: (i) retinal responses based on the first and second sets of functional OCT data, which may be presented in the same (or same kind of) graph or table in order to enable the healthcare practitioner to see the absolute values ‘side by side’—this is applicable to both the correlation strength variations over time (which may, for example, be plotted on a graph) and the derived markers (which may, for example, be presented in columns or rows of a table); and (ii) the difference or a ratio between the retinal responses based on the first and second sets of functional OCT data. Colour and hue may be used to show the magnitude and sign (e.g. red for negative and blue for positive) of the difference, for example. An example of a functional OCT report defined by such image data is illustrated inFIG.10. It will be appreciated from the foregoing that the fifth example embodiment provides another example of a computer-implemented method of processing functional OCT image data, which has been acquired by an OCT imaging device200scanning a retina of a subject while the retina is being repeatedly stimulated by a light stimulus, to generate image data defining an image that provides an indication of a response of the retina to the light stimulus. This method comprises receiving, as the functional OCT image data: OCT image data that has been generated by the OCT imaging device200repeatedly scanning a scanned region of the retina over a time period T; and stimulus data defining a sequence S of stimulus indicators (s1, s2, s3) each being indicative of a stimulation of the retina by the light stimulus in a respective time interval of a sequence of time intervals that spans the time period T. The method also makes use of an alternative way of calculating a correlation between a sequence of B-scans500that is based on the OCT image data and stimulus indicators in the sequence S of stimulus indicators, and uses the calculated correlation to generate an image which indicates at least one of: the response of the scanned region of the retina to the light stimulus as a function of time; one or more properties of a curve defining the response of the scanned region of the retina to the light stimulus as a function of time; and a spatial variation, in the scanned region of the retina, of one or more properties of the curve defining the response of the scanned region of the retina to the light stimulus as a function of time, the spatial variation being overlaid on an en-face representation of at least a portion the retina which includes the scanned region. Embodiment 6 In the fifth example embodiment, the correlation calculator module120-5is configured to calculate the rolling window correlation between the sequence of B-scans500and the sequence S of stimulus indicators received from the OCT imaging device200, and the response generator module125-5is configured to subsequently process the resulting three-dimensional array700′ of combined correlation values (in step S50-5ofFIG.22) so as to generate a two-dimensional array800′ of combined correlation values, by taking the average of the combined correlation values in the depth (d) direction. However, the averaging operation may, as in the present example embodiment, alternatively be performed on the B-scans prior to their correlation with the sequence S of stimulus indicators, thereby simplifying and speeding up the correlation calculation. FIG.24is a schematic illustration of an apparatus100-6according to the sixth example embodiment, which comprises, in addition to the receiver module110and the image data generator module130that are the same as those in apparatus100-5, a B-scan processing module115which is the same as that in the second example embodiment, a response generator module125-6, and a correlation calculator module120-6. The apparatus100-6of the present example embodiment thus differs from the apparatus100-5of the fifth example embodiment only by comprising the B-scan processing module115, the response generator module125-6, and the correlation calculator module120-6, whose functionality is explained in detail below. The following description of the sixth example embodiment will therefore focus on these differences, with all other details of the fifth example embodiment, which are applicable to the sixth example embodiment, not being repeated here for sake of conciseness. It should be noted that the variations and modifications which may be made to the fifth example embodiment, as described above, are also applicable to the sixth example embodiment. It should also be noted that one or more of the illustrated components of the apparatus100-6may be implemented in the form of a programmable signal processing hardware as described above with reference toFIG.2, or alternatively in the form of non-programmable hardware, such as an application-specific integrated circuit (ASIC). FIG.25is a flow diagram illustrating a method by which the apparatus100-6of the sixth example embodiment processes functional OCT data to generate an indication of a response of the retina10to the light stimulus. In step S10ofFIG.25(which is same as step S10inFIG.20), the receiver module110receives from the OCT imaging device200, as the functional OCT image data: (i) OCT image data (specifically, in the form of a sequence of B-scans500) that has been generated by the OCT imaging device200repeatedly scanning the scanned region R of the retina10over a time period T; and (ii) stimulus data defining the sequence of s stimulus indicators, each indicative of a stimulation of the retina by the light stimulus in a respective time interval, T/s, of a sequence of time intervals that spans the time period T. In step S15ofFIG.25, the B-scan processing module115converts the sequence of B-scans500received by the receiver module110in step S10into a sequence of reduced B-scans550, by replacing each A-scan in the sequence of A-scans forming each B-scan400with a respective average value of A-scan elements of the A-scan, as illustrated inFIG.13. In step S20-6ofFIG.25, the correlation calculator module120-6calculates the rolling window correlation between reduced B-scans in the sequence of reduced B-scans550and stimulus indicators s1, s2, s3. . . in the sequence S of stimulus indicators by calculating, for each of the stimulus indicators, a correlation between stimulus indicators in the window comprising the stimulus indicator and the predetermined number of adjacent stimulus indicators, and reduced B-scans of the sequence of reduced B-scans550that are based on OCT image data generated while the retina10was being stimulated in accordance with the stimulus indicators in the window. By way of an example, the correlation calculator module120-6of the present example embodiment calculates, for each of the stimulus indicators, a correlation between stimulus indicators in a windowed portion of the sequence S consisting of a stimulus indicator located at a predetermined sequence position in the windowed portion (e.g. the first sequence indicator in the windowed portion), and a predetermined number of adjacent (e.g. subsequent) stimulus indicators, and corresponding reduced B-scans of the sequence of reduced B-scans that are based on a portion of the OCT image data generated while the retina10was being stimulated in accordance with the stimulus indicators in the window. In step S30-6ofFIG.25, the response generator module125-6combines the calculated correlations to generate, as the indication of the response of the retina10to the light stimulus, a two-dimensional array of combined correlation values (as shown at800′ in FIG.23(a)) indicating the response of the retina10to the light stimulus as a function of location in the scanned region R of the retina10and time. The two-dimensional array800′ of combined correlation values may be processed by the image data generator module130to generate image data in the same way as in the fifth example embodiment, and/or the response generator module125-6may pre-process the two-dimensional array800′ of combined correlation values and/or convert the two-dimensional array of combined correlation values (or the normalised two-dimensional array of combined correlation values, as the case may be) to a sequence of combined correlation values in the same way as the response generator module125-5of the fifth example embodiment. The sequence of combined correlation values may further be processed by the image data generator module130to generate image data in the same way as in step S60of the fifth example embodiment. Embodiment 7 The processing of functional OCT data that is performed by the apparatus100-5of the fifth example embodiment allows an indication of the functional response of a scanned region R of the retina10to be obtained, based on a correlation which is computed for the whole retinal depth covered by the scan. However, it may be valuable for determining disease diagnosis to be able to generate an indication of the individual functional responses of one or more retinal layers corresponding to different cell types (e.g. photoreceptors, retinal pigment epithelium, retinal nerve fiber layer, etc.). Such enhanced functionality is provided by the apparatus100-7of the seventh example embodiment, which will now be described with reference toFIGS.26and27. FIG.26is a schematic illustration of an apparatus100-7for processing functional OCT image data to generate an indication of the individual responses of one or more layers of the retina10to the light stimulus, according to the seventh example embodiment. The apparatus100-7comprises the same receiver module110as the first, second, fifth and sixth example embodiments, a B-scan processing module117which is the same as that of the third example embodiment, a correlation calculator module120-7, a response generator module125-7, and an image generator module130which is the same as that of the first, second, fifth and sixth example embodiments. It should also be noted that one or more of the illustrated components of the apparatus100-7may be implemented in the form of a programmable signal processing hardware as described above with reference toFIG.2, or alternatively in the form of non-programmable hardware, such as an application-specific integrated circuit (ASIC). Processing operations performed by the apparatus100-7will now be described with reference toFIG.27. FIG.27is a flow diagram illustrating a method by which the apparatus100-7of the seventh example embodiment processes functional OCT data to generate an indication of the response of one or more layers of the retina10to the light stimulus. In step S10ofFIG.27, the receiver module110receives the functional OCT image data from the OCT imaging device200. Step S10inFIG.27is the same as step S10inFIGS.3,12,15,18,20and25, and will therefore not be described in further detail here. In step S12ofFIG.27, the B-scan processing module117identically segments each B-scan400in the sequence of B-scans500into a plurality of B-scan layers, so that each B-scan layer comprises respective sections of the A-scans forming the B-scan400. Step S12inFIG.27is the same as step S12inFIG.15, and its description will therefore not be repeated here. The B-scan processing module117further concatenates corresponding B-scan layers from the segmented B-scans to generate sequences of concatenated B-scan layers. Each of the sequences of concatenated B-scan layers thus forms a three-dimensional array of A-scan elements, which corresponds to a respective later of the retina10. In step S20-7ofFIG.27, the correlation calculator module120-7calculates, for each of at least one sequence of concatenated B-scan layers of the sequences of concatenated B-scan layers generated in step S12ofFIG.27, a respective rolling window correlation between the sequence of concatenated B-scan layers and the sequence S of stimulus indicators by calculating, for each stimulus indicator (s1, s2, s3) in the sequence of stimulus indicators, a correlation between stimulus indicators in the window comprising the stimulus indicator and the predetermined number of adjacent stimulus indicators, and B-scan layers of the B-scan layers that are based on B-scans which have been generated by the OCT imaging device100while the retina10was being stimulated in accordance with the stimulus indicators in the window. In the present example embodiment, the correlation calculator module120-7thus calculates, for each of the stimulus indicators, a correlation between stimulus indicators in a windowed portion of the sequence S consisting of a stimulus indicator located at a predetermined sequence position in the windowed portion (e.g. the first sequence indicator in the windowed portion), and a predetermined number of adjacent (e.g. subsequent) stimulus indicators, and corresponding B-scan layers of the sequence of B-scan layers that are based on a portion of the OCT image data generated while the retina10was being stimulated in accordance with the stimulus indicators in the window. In step S30-7ofFIG.27, for each of the at least one sequence of concatenated B-scan layers, the response generator module125-7combines the correlations calculated in step S20-7to generate a respective three-dimensional array of values (“response volume”) that provides an indication of a response of the respective layer of the retina10to the light stimulus. Each resulting three-dimensional array of combined correlation values may further be processed by the response generator module125-7, and the results of those further processing operations may be used by the image data generator module130to generate image data defining an image which indicates the response of the corresponding layer of the retina10to the light stimulus for display to a user of the apparatus100-7, using the further processing operations that have been explained in the above description of the first embodiment, with reference toFIG.5. More particularly, the response volume corresponding to each retinal layer may be reduced to a two-dimensional response image for easier visualisation by taking the average in the depth (d) direction, i.e. one value per A-scan per lag time point. Thus, the response generator module125-7may convert each three-dimensional array of combined correlation values, which is a/3×blag×d pixels in size in the present example embodiment, into a respective two-dimensional array of combined correlation values, which is a/3×blagpixels in size, by replacing each one-dimensional array of combined correlation values in the three-dimensional array, which one-dimensional array has been calculated using sections of A-scans that are identically located in respective B-scans of the sequence of B-scans, with a single value that is an average of the combined correlation values in the one-dimensional array. Thus, each array element of the one-dimensional array is calculated on the basis of a corresponding element of an A-scan. The two-dimensional array of combined correlation values indicates the response of the corresponding layer of the retina10to the light stimulus as a function of location along the scanned region R of the retina10(i.e. as a function of position along the line defining the scan pattern) and time. The image data generator module130may use at least one of the two-dimensional arrays of combined correlation values to generate image data defining an image which indicates the response, to the light stimulus, of a respective layer of the retina10corresponding to each of the at least one of the two-dimensional arrays as a function of location in the scanned region R of the retina10and time. However, it may be preferable to pre-process at least some of the two-dimensional arrays of combined correlation values prior to image data generation (or prior to the alternative further processing operation described below), in order to accentuate the time-dependent variability of the signal, i.e. the variation of the retinal layer response to light stimulation over time. Such pre-processing may be desirable in cases where the response variability in the A-scan direction is greater than in the time lag direction. The response generator module125-7may pre-process one or more of the two-dimensional arrays of combined correlation values, each comprising a sequence of blagone-dimensional arrays, each indicating the response of the corresponding layer of the retina10to the light stimulus as a function of location in the scanned region R of the retina10, to generate a normalised two-dimensional array of combined correlation values. The response generator module125-7may generate the normalised two-dimensional array of combined correlation values by subtracting the first one-dimensional array in the sequence of one-dimensional arrays from each remaining one-dimensional array in the sequence of one-dimensional arrays. Alternatively, the response generator module125-7may generate a normalised two-dimensional array of combined correlation values by calculating an array of averaged combined correlation values, such that each averaged combined correlation value in the array of averaged combined correlation values is an average (mean) of the combined correlation values that are correspondingly located in the sequence of one-dimensional arrays, and subtracting the calculated array of averaged combined correlation values from each of the one-dimensional arrays in the sequence of one-dimensional arrays (in other words, performing a vector subtraction of the calculated array of averaged combined correlation values from each of the one-dimensional arrays). In both of these alternative ways of calculating normalised two-dimensional array of combined correlation values, the resulting normalised two-dimensional array of combined correlation values indicates the response of the corresponding layer of the retina to the light stimulus as a function of location in the scanned region R of the retina10and time. The image data generator module130may use each normalised two-dimensional array of combined correlation values to generate image data defining an image that indicates the response of the corresponding layer of the retina10to the light stimulus as a function of location in the scanned region R of the retina10and time. To allow the response of one or more layers of the retina to the light stimulus to be illustrated in a form that may be more useful for a healthcare practitioner such as an ophthalmologist, the response generator module125-7may convert the two-dimensional array of combined correlation values (or the normalised two-dimensional array of combined correlation values, as the case may be) corresponding to each of one or more of the retinal layers to a sequence of correlation values by replacing each of the one-dimensional arrays of combined correlation values in the two-dimensional array (each of the one-dimensional arrays indicating the response of the corresponding layer of the retina10to the light stimulus as a function of location in the scanned region R of the retina10) with a single respective value that is an average of the combined correlation values in the one-dimensional array, each sequence of combined correlation values indicating a response of the respective layer of the retina in the scanned region to the light stimulus as a function of time. The image data generator module130may use one or more of the sequences of combined correlation values to generate image data defining an image that indicates the response of the respective one or more layers of the retina10in the scanned region R of the retina10to the light stimulus. Similar to the fifth and sixth example embodiments described above, the image data generator module130may use one or more sequences of combined correlation values to generate an image which indicates at least one of: the response of the respective one or more layers of the retina10in the scanned region R to the light stimulus as a function of time; one or more properties of a respective one or more curves defining the response of the respective one or more layers of the retina10in the scanned region R to the light stimulus as a function of time; and a spatial variation, in the scanned region R of the retina10, of one or more properties of the respective one or more curves defining the response of the respective one or more layers of the retina10in the scanned region R to the light stimulus as a function of time, the spatial variation being overlaid on an en-face representation of at least a portion the retina10which includes the scanned region R. Embodiment 8 In the seventh example embodiment, the correlation calculator module120-7is, in one configuration, configured to calculate, for each of at least one sequence of concatenated B-scan layers of the concatenated sequences of B-scan layers, a respective rolling window correlation between the sequence of concatenated B-scan layers and the sequence S of stimulus indicators received from the OCT imaging device200, and the response generator module125-7is configured to subsequently process the resulting three-dimensional array of correlation values so as to generate a two-dimensional array of combined correlation values, by taking an average of the combined correlation values in the depth (d) direction. However, the averaging operation may, as in the present example embodiment, alternatively be performed on the one or more of the sequences of concatenated B-scan layers prior to their correlation with the sequence S of stimulus indicators, thereby simplifying and speeding up the correlation calculation. FIG.28is a schematic illustration of an apparatus100-8according to the eighth example embodiment, which comprises, in addition to the receiver module110and the image data generator module130that are the same as those in apparatus of the foregoing example embodiments, and a B-scan processing module118which is the same as in the fourth example embodiment, a correlation calculator module120-8and a response generator module125-8which are described in detail below. It should be noted that one or more of the illustrated components of the apparatus100-8may be implemented in the form of a programmable signal processing hardware as described above with reference toFIG.2, or alternatively in the form of non-programmable hardware, such as an application-specific integrated circuit (ASIC). FIG.29is a flow diagram illustrating a method by which the apparatus100-8of the eighth example embodiment processes functional OCT data to generate an indication of a response of the retina10to the light stimulus. In step S10ofFIG.29, the receiver module110receives the functional OCT image data from the OCT imaging device200. Step S10inFIG.29is the same as step S10inFIG.3, for example, and will therefore not be described in further detail here. In step S12ofFIG.29, the B-scan processing module118identically segments each B-scan400in the sequence of B-scans500into a plurality of B-scan layers, so that each B-scan layer comprises respective sections of the A-scans forming the B-scan400. Step S12inFIG.29is the same as step S12inFIG.15, for example, and will therefore not be described in further detail here. Each of the sequences of concatenated B-scan layers forms a three-dimensional array of A-scan elements, which corresponds to a respective later of the retina10. In step S17ofFIG.29, the B-scan processing module118converts each of at least one of the sequences of concatenated B-scan layers into a respective sequence of concatenated reduced B-scan layers, by replacing, for each B-scan layer in each of the at least one sequence of concatenated B-scan layers, the sections of the A-scans forming the B-scan layer with corresponding values of an average of A-scan elements in the sections of the A-scans. For example, in the illustrative example ofFIG.16, the B-scan processing module118converts the three-dimensional array formed by the first sequence of concatenated B-scan layers,450a, into a two-dimensional array, by replacing the first column of B-scan layer (or segment)400-1a, comprising A-scan elements a1and a2, with a single value that is an average of a1and a2, with the remaining columns of B-scan segment400-1a, and the other B-scan segments400-1b,400-1c, etc. of the first sequence of concatenated B-scan layers450abeing processed in the same way. The B-scan processing module118may likewise process the second sequence of concatenated B-scan layers450band/or the third sequence of concatenated B-scan layers450cin addition to, or alternatively to, the first sequence of concatenated B-scan layers450a. Thus, the B-scan processing module118can convert each of one or more of the three-dimensional arrays of OCT measurement values shown in the example ofFIG.16, each of which is a/3×blag×d pixels in size, into a respective two-dimensional array of values, which is a/3×blagpixels in size. In step S20-8ofFIG.29, the correlation calculator module120-8calculates, for each of at least one sequence of concatenated reduced B-scan layers of the sequences of concatenated reduced B-scan layers generated in step S17ofFIG.29, a respective rolling window correlation between reduced B-scan layers in the sequence of concatenated reduced B-scan layers and stimulus indicators (s1, s2, s3) in the sequence S of stimulus indicators, specifically by calculating, for each stimulus indicator in the sequence S of stimulus indicators, a correlation between stimulus indicators in the window comprising the stimulus indicator and the predetermined number of adjacent stimulus indicators, and values of the averages calculated using B-scan layers comprised in B-scans that have been generated by the OCT imaging device200while the retina10was being stimulated in accordance with the stimulus indicators in the window. In step S30-8ofFIG.29, the response generator module125-8generates, for each of the at least one sequence of concatenated reduced B-scan layers, an indication of a response of a layer of the retina10corresponding to the sequence of concatenated reduced B-scan layers to the light stimulus, by combining the calculated correlations to generate a two-dimensional array of correlation values indicating the response of the layer of the retina to the light stimulus as a function of location in the scanned region R of the retina10and time. Each resulting two-dimensional array of correlation values may further be processed by the response generator module125-8in the same way as the two-dimensional array(s) of correlation values is/are processed by the response generator module125-7in the seventh example embodiment described above. Thus, the image data generator module130may use at least one of the two-dimensional arrays of correlation values to generate image data defining an image which indicates the response, to the light stimulus, of a respective layer of the retina10corresponding to each of the at least one of the two-dimensional arrays as a function of location in the scanned region R of the retina10and time. However, it may be preferable to pre-process at least some of the two-dimensional arrays of correlation values prior to image data generation (or prior to the alternative further processing operation described below), in order to accentuate the time-dependent variability of the signal, i.e. the variation of the retinal layer response to light stimulation over time. Such pre-processing may be desirable in cases where the response variability in the A-scan direction is greater than in the time lag direction. The response generator module125-8may pre-process one or more of the two-dimensional arrays of correlation values, each comprising a sequence of blagone-dimensional arrays, each array indicating the response of the corresponding layer of the retina10to the light stimulus as a function of location in the scanned region R of the retina10, to generate a normalised two-dimensional array of correlation values. The response generator module125-8may generate a normalised two-dimensional array of correlation values (indicating the response of the corresponding layer of the retina10to the light stimulus as a function of location in the scanned region R of the retina10and time) using one of the processes described in the third example embodiment, for example. The image data generator module130may use each normalised two-dimensional array of correlation values to generate image data defining an image that indicates the response of the corresponding layer of the retina10to the light stimulus as a function of location in the scanned region R of the retina10and time. To allow the response of one or more layers of the retina to the light stimulus to be illustrated in a form that may be more useful for a healthcare practitioner such as an ophthalmologist, the response generator module125-8may convert the two-dimensional array of correlation values (or the normalised two-dimensional array of correlation values, as the case may be) corresponding to each of one or more of the retinal layers to a sequence of correlation values by replacing each of the one-dimensional arrays of correlation values in the two-dimensional array (each of the one-dimensional arrays indicating the response of the corresponding layer of the retina10to the light stimulus as a function of location in the scanned region R of the retina10) with a single respective value that is an average of the correlation values in the one-dimensional array, each sequence of correlation values indicating a response of the respective layer of the retina in the scanned region to the light stimulus as a function of time. The image data generator module130may use one or more of the sequences of correlation values to generate image data defining an image that indicates the response of the respective one or more layers of the retina10in the scanned region R of the retina to the light stimulus. Similar to the third example embodiment described above, the image data generator module130may use one or more sequences of correlation values to generate an image which indicates at least one of: the response of the respective one or more layers of the retina10in the scanned region R to the light stimulus as a function of time; one or more properties of a respective one or more curves defining the response of the respective one or more layers of the retina10in the scanned region R to the light stimulus as a function of time; and a spatial variation, in the scanned region R of the retina10, of one or more properties of the respective one or more curves defining the response of the respective one or more layers of the retina10in the scanned region R to the light stimulus as a function of time, the spatial variation being overlaid on an en-face representation of at least a portion the retina10which includes the scanned region R. The example aspects described herein avoid limitations, specifically rooted in computer technology, relating to conventional OCT measurement systems and methods that require large amounts of tomographic data to be acquired during retina light stimulation evaluations, and which require correlation of tomographic data with timing information of applied light stimuli. Such conventional methods and systems are complex and unduly demanding on computer resources. By virtue of the example aspects described herein, on the other hand, retina light stimulation evaluations can be performed in a much less complex manner, and in a manner that may require relatively less computer processing and memory resources than those required by the conventional systems/methods, thereby enabling the evaluations to be performed in a more highly computationally- and resource-efficient manner relative to the conventional systems/methods. Also, by virtue of the foregoing capabilities of the example aspects described herein, which are rooted in computer technology, the example aspects described herein improve computers and computer processing/functionality, and also improve the field(s) of at least image processing, optical coherence tomography (OCT) and data processing, and the processing of functional OCT image data. Some of the embodiments described above are summarised in the following examples E1 to E41:E1. An apparatus (100-1;100-2) configured to process functional OCT image data, which has been acquired by an OCT imaging device (200) scanning a retina of a subject while the retina is being repeatedly stimulated by a light stimulus, to generate an indication (700) of a response of the retina to the light stimulus, the apparatus (100-1;100-2) comprising:a receiver module (110) configured to receive, as the functional OCT image data:OCT image data that has been generated by the OCT imaging device (200) repeatedly scanning a scanned region (R) of the retina over a time period (T); andstimulus data defining a sequence (S) of stimulus indicators (s1, s2, s3) each being indicative of a stimulation of the retina by the light stimulus in a respective time interval of a sequence of time intervals that spans the time period (T); anda correlation calculator module (120-1) configured to calculate a rolling window correlation between a sequence of B-scans (500) that is based on the OCT image data and stimulus indicators (s1, s2, s3) in the sequence (S) of stimulus indicators by:calculating, for each stimulus indicator (s1; s2; s3), a product of the stimulus indicator (s1; s2; s3) and a respective windowed portion of the sequence of B-scans (500) comprising a B-scan (400) which is based on a portion of the OCT image data generated while the retina was being stimulated in accordance with the stimulus indicator; andcombining the calculated products to generate the indication (700) of the response of the retina to the light stimulus.E2. The apparatus (100-1) according to E1, wherein:the receiver module (110) is configured to receive a sequence of B-scans (500), which has been generated by the OCT imaging device (200) repeatedly scanning the scanned region (R) of the retina (10) over the time period (T), as the OCT image data; andthe correlation calculator module (120-1) is configured to calculate the rolling window correlation between B-scans in the sequence of B-scans (500) and stimulus indicators (s1, s2, s3) in the sequence (S) of stimulus indicators by calculating, for each stimulus indicator (s1; s2; s3), a product of the stimulus indicator (s1; s2; s3) and a respective windowed portion of the sequence of B-scans (500) comprising a B-scan (400) which has been generated by the OCT imaging device (200) while the retina was being stimulated in accordance with the stimulus indicator (s1; s2; s3).E3. The apparatus (100-1) according to E2, wherein the correlation calculator module (120-1) is configured to:combine the calculated products to generate a three-dimensional array (700) of correlation values, the three-dimensional array (700) of correlation values comprising one-dimensional arrays of correlation values that have each been calculated using A-scans that are identically located in respective B-scans (400) of the sequence of B-scans (500); andconvert the three-dimensional array (700) of correlation values to a two-dimensional array (800) of correlation values by replacing each of the one-dimensional arrays of correlation values with a respective single value that is an average of the correlation values in the one-dimensional array, the two-dimensional array (800) of correlation values indicating the response of the retina to the light stimulus as a function of location along the scanned region (R) of the retina (10) and time.E4. The apparatus (100-2) according to E1, wherein:the receiver module (110) is configured to receive a sequence of B-scans (500), which has been generated by the OCT imaging device (200) repeatedly scanning the scanned region (R) of the retina (10) over the time period (T), as the OCT image data, each of the B-scans (400) being formed by a sequence of A-scans;the apparatus (100-2) further comprises a B-scan processing module (115) configured to convert the sequence of B-scans (500) into a sequence of reduced B-scans (550), by replacing each A-scan in the sequence of A-scans forming each B-scan with a respective average value of A-scan elements of the A-scan; andthe correlation calculator module (120-2) is configured to:calculate the rolling window correlation between reduced B-scans in the sequence of reduced B-scans (550) and stimulus indicators (s1, s2, s3) in the sequence (S) of stimulus indicators by calculating, for each stimulus indicator (s1; s2; s3), a product of the stimulus indicator (s1; s2; s3) and a respective windowed portion of the sequence of reduced B-scans (550) comprising a reduced B-scan which is based on a B-scan of the sequence of B-scans (500) which has been generated by the OCT imaging device (200) while the retina (10) was being stimulated in accordance with the stimulus indicator (s1; s2; s3); andcombine the calculated products to generate, as the indication of the response of the retina (10) to the light stimulus, a two-dimensional array (800) of correlation values indicating the response of the retina (10) to the light stimulus as a function of location in the scanned region (R) of the retina (10) and time.E5. The apparatus (100-1;100-2) according to E3 or E4, whereinthe two-dimensional array (800) of correlation values comprises an array of one-dimensional arrays of correlation values each indicating the response of the retina (10) to the light stimulus as a function of location in the scanned region (R) of the retina (10), andthe correlation calculator module (120-1;120-2) is further configured to convert the two-dimensional array (800) of correlation values to a sequence of correlation values by replacing each of the one-dimensional arrays of correlation values in the two-dimensional array (800) with a single respective value that is an average of the correlation values in the one-dimensional array, the sequence of correlation values indicating a response of the scanned region (R) of the retina (10) to the light stimulus as a function of time.E6. The apparatus (100-1;100-2) according to E3 or E4, whereinthe two-dimensional array (800) of correlation values comprises a sequence of one-dimensional arrays each indicating the response of the retina (10) to the light stimulus as a function of location in the scanned region (R) of the retina (10), andthe correlation calculator module (120-1;120-2) is further configured to generate a normalised two-dimensional array (900-1) of correlation values by subtracting the first one-dimensional array (A1) in the sequence of one-dimensional arrays from each remaining one-dimensional array in the sequence of one-dimensional arrays, the normalised two-dimensional array (900-1) of correlation values indicating the response of the retina to the light stimulus as a function of location in the scanned region of the retina and time.E7. The apparatus (100-1;100-2) according to E3 or E4, whereinthe two-dimensional array (800) of correlation values comprises an array of one-dimensional arrays each indicating the response of the retina (10) to the light stimulus as a function of location in the scanned region (R) of the retina, andthe correlation calculator module (120-1;120-2) is further configured to generate a normalised two-dimensional array (900-2) of correlation values by calculating an array of averaged correlation values such that each averaged correlation value in the array of averaged correlation values is an average of the correlation values that are correspondingly located in the one-dimensional arrays, and subtracting the calculated array of averaged correlation values from each of the one-dimensional arrays in the array of one-dimensional arrays, the normalised two-dimensional array (900-2) of correlation values indicating the response of the retina (10) to the light stimulus as a function of location in the scanned region (R) of the retina (10) and time.E8. The apparatus (100-1;100-2) according to E6 or E7, whereinthe normalised two-dimensional array (900-1;900-2) comprises one-dimensional arrays of correlation values, each one-dimensional array of correlation values being indicative of the response of the retina to the light stimulus as a function of location in the scanned region of the retina, andthe correlation calculator module (120-1;120-2) is further configured to convert the normalised two-dimensional array (900-1;900-2) of correlation values to a sequence of correlation values by replacing each of the one-dimensional arrays of correlation values in the normalised two-dimensional array (900-1;900-2) with a respective single value that is an average of the correlation values in the one-dimensional array, the sequence of correlation values indicating a response of the scanned region (R) of the retina (10) to the light stimulus as a function of time.E9. The apparatus (100-1;100-2) according to E5 or E8, further comprising:an image data generator module (130) configured to use the sequence of correlation values to generate image data defining an image which indicates the response of the scanned region of the retina to the light stimulus.E10. The apparatus (100-1;100-2) according to E9, wherein the image data generator module (130) is configured to use the sequence of correlation values to generate an image which indicates at least one of:the response of the scanned region (R) of the retina (10) to the light stimulus as a function of time;one or more properties of a curve defining the response of the scanned region (R) of the retina (10) to the light stimulus as a function of time; anda spatial variation, in the scanned region (R) of the retina (10), of one or more properties of the curve defining the response of the scanned region (R) of the retina (10) to the light stimulus as a function of time, the spatial variation being overlaid on an en-face representation (1000) of at least a portion the retina (10) which includes the scanned region (R).E11. The apparatus (100-3) according to E1, wherein:the receiver module (110) is configured to receive a sequence of B-scans, which has been generated by the OCT imaging device (200) repeatedly scanning the scanned region of the retina over the time period, as the OCT image data;the apparatus (100-3) further comprises a B-scan processing module (117) configured to segment each B-scan (400) in the sequence of B-scans (500) into a plurality of B-scan layers (400-1a,400-1b,400-1c) so that each B-scan layer comprises respective sections of the A-scans forming the B-scan (400), and concatenate corresponding B-scan layers from the segmented B-scans to generate sequences of concatenated B-scan layers (450a,450b,450c);the correlation calculator module (120-3) is configured to calculate, for each of at least one sequence of concatenated B-scan layers of the sequences of concatenated B-scan layers (450a,450b,450c), a respective rolling window correlation between concatenated B-scan layers in the sequence of concatenated B-scan layers and stimulus indicators (s1, s2, s3) in the sequence (S) of stimulus indicators by:calculating, for each stimulus indicator (s1; s2; s3), a product of the stimulus indicator (s1; s2; s3) and a respective windowed portion of the sequence of concatenated B-scan layers comprising a B-scan layer of the B-scan layers which is based on a B-scan (400) which has been generated by the OCT imaging device (200) while the retina (10) was being stimulated in accordance with the stimulus indicator (s1; s2; s3); andcombining the calculated products to generate an indication of a response of a layer of the retina (10) corresponding to the sequence of concatenated B-scan layers to the light stimulus.E12. The apparatus (100-3) according to E11, wherein the correlation calculator module (120-3) is configured to:calculate, as the rolling window correlation for each of the at least one sequence of concatenated B-scan layers, a respective three-dimensional array of correlation values, each three-dimensional array of correlation values comprising one-dimensional arrays of correlation values that have been calculated using sections of A-scans that are identically located in respective B-scans of the sequence of B-scans; andconvert each of at least one of the three-dimensional arrays of correlation values to a respective two-dimensional array of correlation values by replacing each of the one-dimensional arrays of correlation values in the three-dimensional array with a respective single value that is an average of the correlation values in the one-dimensional array, the two-dimensional array of correlation values indicating the response of the corresponding layer of the retina to the light stimulus as a function of location along the scanned region of the retina and time.E13. The apparatus (100-4) according to E1, wherein:the receiver module (110) is configured to receive a sequence of B-scans, which has been generated by the OCT imaging device repeatedly scanning the scanned region of the retina over the time period, as the OCT image data;the apparatus further comprises a B-scan processing module (118) configured to:segment each B-scan in the sequence of B-scans into a plurality of B-scan layers so that each B-scan layer comprises respective sections of the A-scans forming the B-scan, and concatenating corresponding B-scan layers from the segmented B-scans to generate sequences of concatenated B-scan layers; andconvert each of at least one sequence of concatenated B-scan layers of the sequences of concatenated B-scan layers into a respective sequence of concatenated reduced B-scan layers, by replacing, for each B-scan layer in each of the at least one sequence of concatenated B-scan layers, the sections of the A-scans forming the B-scan layer with corresponding values of an average of A-scan elements in the sections of the A-scans; andthe correlation calculator module (120-4) is configured to calculate, for each of the at least one sequence of concatenated reduced B-scan layers, a respective rolling window correlation between reduced B-scan layers in the sequence of concatenated reduced B-scan layers and stimulus indicators in the sequence of stimulus indicators by:calculating, for each stimulus indicator, a product of the stimulus indicator and a respective windowed portion of the sequence of concatenated reduced B-scan layers comprising a reduced B-scan layer which is based on a B-scan that has been generated by the OCT imaging device while the retina was being stimulated in accordance with the stimulus indicator; andcombining the calculated products to generate a two-dimensional array of correlation values indicating the response of a layer of the retina corresponding to the sequence of concatenated reduced B-scan layers to the light stimulus as a function of location in the scanned region of the retina and time.E14. The apparatus (100-3;100-4) according to E12 or E13, wherein the correlation calculator module (120-3;120-4) is further configured to convert each of at least one of two-dimensional arrays of correlation values to a respective sequence of correlation values by replacing each one-dimensional array of correlation values in the two-dimensional array, which one-dimensional array indicates the response of the layer of the retina (10) corresponding to the two-dimensional array to the light stimulus as a function of location in the scanned region (R) of the retina (10), with a single value that is an average of the correlation values in the one-dimensional array, the sequence of correlation values indicating a response of the layer of the retina (10) in the scanned region (R) to the light stimulus as a function of time.E15. The apparatus (100-3;100-4) according to E12 or E13, whereineach two-dimensional array of correlation values comprises a sequence of one-dimensional arrays each indicating the response of the respective layer of the retina (10) to the light stimulus as a function of location in the scanned region (R) of the retina (10), andthe correlation calculator module (120-3;120-4) is further configured to process each two-dimensional array of correlation values to generate a respective normalised two-dimensional array of correlation values by subtracting the first one-dimensional array in the sequence of one-dimensional arrays from each remaining one-dimensional array in the sequence of one-dimensional arrays, the normalised two-dimensional array of correlation values indicating the response of the corresponding layer of the retina (10) to the light stimulus as a function of location in the scanned region (R) of the retina (10) and time.E16. The apparatus (100-3;100-4) according to E12 or E13, whereineach two-dimensional array of correlation values comprises an array of one-dimensional arrays each indicating the response of the respective layer of the retina (10) to the light stimulus as a function of location in the scanned region (R) of the retina (10), andthe correlation calculator module (120-3;120-4) is further configured to process each two-dimensional array of correlation values to generate a respective normalised two-dimensional array of correlation values by calculating an array of averaged correlation values such that each averaged correlation value in the array of averaged correlation values is an average of the correlation values that are correspondingly located in the one-dimensional arrays, and subtracting the calculated array of averaged correlation values from each of the one-dimensional arrays in the array of one-dimensional arrays, the normalised two-dimensional array of correlation values indicating the response of the corresponding layer of the retina (10) to the light stimulus as a function of location in the scanned region (R) of the retina (10) and time.E17. The apparatus (100-3;100-4) according to E15 or E16, wherein the correlation calculator module (120-3;120-4) is further configured to convert each normalised two-dimensional array of correlation values to a respective sequence of correlation values by replacing each one-dimensional array of correlation values in the normalised two-dimensional array, which one-dimensional array indicates the response of the layer of the retina corresponding to the normalised two-dimensional array of correlation values to the light stimulus as a function of location in the scanned region of the retina, with a single value that is an average of the correlation values in the one-dimensional array, the sequence of correlation values indicating a response of the layer of the retina (10) in the scanned region (R) to the light stimulus as a function of time.E18. The apparatus (100-3;100-4) according to E14 or E17, further comprising:an image data generator module (130) configured to use one or more of the sequences of correlation values to generate image data defining an image that indicates the response of the respective one or more of layers of the retina (10) in the scanned region (R) of the retina (10) to the light stimulus.E19. The apparatus (100-3;100-4) according to E18, wherein the image data generator module (130) is configured to use the one or more sequences of correlation values to generate an image which indicates at least one of:the response of the respective one or more layers of the retina (10) in the scanned region (R) to the light stimulus as a function of time;one or more properties of a respective one or more curves defining the response of the respective one or more layers of the retina (10) in the scanned region (R) to the light stimulus as a function of time; anda spatial variation, in the scanned region of the retina (10), of one or more properties of the respective one or more curves defining the response of the respective one or more layers of the retina (10) in the scanned region (R) to the light stimulus as a function of time, the spatial variation being overlaid on an en-face representation of at least a portion the retina (10) which includes the scanned region (R).E20. An apparatus (100-5) configured to process functional OCT image data, which has been acquired by an OCT imaging device (200) scanning a retina (10) of a subject while the retina (10) is being repeatedly stimulated by a light stimulus, to generate an indication of a response of the retina to the light stimulus, the apparatus (100-5) comprising:a receiver module (110) configured to receive, as the functional OCT image data:OCT image data that has been generated by the OCT imaging device (200) repeatedly scanning a scanned region (R) of the retina (10) over a time period (T); andstimulus data defining a sequence (S) of stimulus indicators (s1, s2, s3) each being indicative of a stimulation of the retina (10) by the light stimulus in a respective time interval of a sequence of time intervals that spans the time period (T);a correlation calculator module (120-5) configured to calculate a rolling window correlation between a sequence of B-scans (500) that is based on the OCT image data and at least some of the stimulus indicators (s1, s2, s3) in the sequence (S) of stimulus indicators by calculating, for each stimulus indicator, a correlation betweenstimulus indicators in a window comprising the stimulus indicator and a predetermined number of adjacent stimulus indicators, andB-scans of the sequence of B-scans (500) that are based on a portion of the OCT image data generated while the retina (10) was being stimulated in accordance with the stimulus indicators in the window; anda response generator module (125) configured to generate the indication of the response of the retina (10) to the light stimulus by combining the calculated correlations.E21. The apparatus (100-5) according to E20, wherein:the receiver module (110) is configured to receive a sequence of B-scans, which has been generated by the OCT imaging device (200) repeatedly scanning the scanned region (R) of the retina (10) over the time period, as the OCT image data;the correlation calculator module (120-5) is configured to calculate the rolling window correlation between the sequence of B-scans (500) and the sequence (S) of stimulus indicators by calculating, for each stimulus indicator (s1, s2, s3) in the sequence (S) of stimulus indicators, a correlation betweenstimulus indicators in the window comprising the stimulus indicator and the predetermined number of adjacent stimulus indicators, andB-scans of the sequence of B-scans (500) that have been generated by the OCT imaging device (200) while the retina (10) was being stimulated in accordance with the stimulus indicators in the window.E22. The apparatus (100-5) according to E21, wherein the response generator module (125) is configured to combine the calculated correlations to generate a three-dimensional array of combined correlation values, the three-dimensional array of combined correlation values comprising one-dimensional arrays of combined correlation values that have each been calculated using A-scans that are identically located in respective B-scans of the sequence of B-scans (500), the response generator module (125) being configured to generate the indication of the response of the retina (10) to the light stimulus by:converting the three-dimensional array of combined correlation values to a two-dimensional array of combined correlation values by replacing each of the one-dimensional arrays of combined correlation values with a respective single value that is an average of the combined correlation values in the one-dimensional array, the two-dimensional array of combined correlation values indicating the response of the retina (10) to the light stimulus as a function of location along the scanned region (R) of the retina (10) and time.E23. The apparatus (100-6) according to E20, wherein:the receiver module (110) is configured to receive a sequence of B-scans, which has been generated by the OCT imaging device (200) repeatedly scanning the scanned region (R) of the retina (10) over the time period (T), as the OCT image data, each of the B-scans being formed by a sequence of A-scans;the apparatus (100-6) further comprises a B-scan processing module (115) configured to convert the sequence of B-scans into a sequence of reduced B-scans, by replacing each A-scan in the sequence of A-scans forming each B-scan with a respective average value of A-scan elements of the A-scan;the correlation calculator module (120-6) is configured to calculate the rolling window correlation between the sequence of reduced B-scans and the sequence of stimulus indicators by calculating, for each stimulus indicator (s1, s2, s3) in the sequence (S) of stimulus indicators, a correlation betweenstimulus indicators in the window comprising the stimulus indicator and the predetermined number of adjacent stimulus indicators, andreduced B-scans of the sequence of reduced B-scans that are based on OCT image data generated while the retina (10) was being stimulated in accordance with the stimulus indicators in the window; andthe indication of the response of the retina (10) to the light stimulus generated by the response generator module (125-6) comprises a two-dimensional array of combined correlation values indicating the response of the retina (10) to the light stimulus as a function of location in the scanned region (R) of the retina (10) and time.E24. The apparatus (100-5;100-6) according to E22 or E23, whereinthe two-dimensional array of combined correlation values comprises an array of one-dimensional arrays of combined correlation values each indicating the response of the retina (10) to the light stimulus as a function of location in the scanned region (R) of the retina (10), andthe response generator module (125-5;125-6) is configured to generate the indication of the response of the retina (10) to the light stimulus by:converting the two-dimensional array of combined correlation values to a sequence of combined correlation values by replacing each of the one-dimensional arrays of combined correlation values in the two-dimensional array with a single respective value that is an average of the combined correlation values in the one-dimensional array, the sequence of combined correlation values indicating a response of the scanned region (R) of the retina (10) to the light stimulus as a function of time.E25. The apparatus (100-5;100-6) according to E22 or E23, wherein the two-dimensional array of combined correlation values comprises a sequence of one-dimensional arrays each indicating the response of the retina (10) to the light stimulus as a function of location in the scanned region (R) of the retina (10), and wherein the response generator module (125-5;125-6) is configured to generate the indication of the response of the retina (10) to the light stimulus further by:generating a normalised two-dimensional array of combined correlation values by subtracting the first one-dimensional array in the sequence of one-dimensional arrays from each remaining one-dimensional array in the sequence of one-dimensional arrays, the normalised two-dimensional array of combined correlation values indicating the response of the retina (10) to the light stimulus as a function of location in the scanned region (R) of the retina (10) and time.E26. The apparatus (100-5;100-6) according to E22 or E23, wherein the two-dimensional array of combined correlation values comprises an array of one-dimensional arrays each indicating the response of the retina (10) to the light stimulus as a function of location in the scanned region (R) of the retina (10), and wherein the response generator module (125-5;125-6) is configured to generate the indication of the response of the retina (10) to the light stimulus by:generating a normalised two-dimensional array of combined correlation values by calculating an array of averaged combined correlation values such that each averaged combined correlation value in the array of averaged combined correlation values is an average of the combined correlation values that are correspondingly located in the one-dimensional arrays, and subtracting the calculated array of averaged combined correlation values from each of the one-dimensional arrays in the array of one-dimensional arrays, the normalised two-dimensional array of combined correlation values indicating the response of the retina (10) to the light stimulus as a function of location in the scanned region (R) of the retina (10) and time.E27. The apparatus (100-5;100-6) according to E25 or E26, whereinthe normalised two-dimensional array comprises one-dimensional arrays of combined correlation values, each one-dimensional array of combined correlation values being indicative of the response of the retina to the light stimulus as a function of location in the scanned region (R) of the retina (10), andthe response generator module (125-5;125-6) is configured to generate the indication of the response of the retina (10) to the light stimulus by:converting the normalised two-dimensional array of combined correlation values to a sequence of combined correlation values by replacing each of the one-dimensional arrays of combined correlation values in the normalised two-dimensional array with a respective single value that is an average of the combined correlation values in the one-dimensional array, the sequence of combined correlation values indicating a response of the scanned region (R) of the retina (10) to the light stimulus as a function of time.E28. The apparatus (100-5;100-6) according to E24 or E27, further comprising:an image data generator module (130) configured to use the sequence of combined correlation values to generate image data defining an image which indicates the response of the scanned region (R) of the retina (10) to the light stimulus as a function of time.E29. The apparatus (100-5;100-6) according to E28, wherein the image data generator module (130) is configured to use the sequence of correlation values to generate an image which indicates at least one of:the response of the scanned region (R) of the retina (10) to the light stimulus as a function of time;one or more properties of a curve defining the response of the scanned region (R) of the retina (10) to the light stimulus as a function of time; anda spatial variation, in the scanned region (R) of the retina (10), of one or more properties of the curve defining the response of the scanned region (R) of the retina (10) to the light stimulus as a function of time, the spatial variation being overlaid on an en-face representation (1000) of at least a portion the retina (10) which includes the scanned region (R).E30. The apparatus (100-7) according to E20, wherein:the receiver module (110) is configured to receive a sequence of B-scans, which has been generated by the OCT imaging device (200) repeatedly scanning the scanned region (R) of the retina (10) over the time period, as the OCT image data;the apparatus further comprises a B-scan processing module (117) configured o segment each B-scan in the sequence of B-scans (500) into a plurality of B-scan layers so that each B-scan layer comprises respective sections of the A-scans forming the B-scan, and concatenate corresponding B-scan layers from the segmented B-scans to generate sequences of concatenated B-scan layers;the correlation calculator module (120-7) is configured to calculate, for each of at least one sequence of concatenated B-scan layers of the sequences of concatenated B-scan layers, a respective rolling window correlation between the sequence of concatenated B-scan layers and the sequence of stimulus indicators by calculating, for each stimulus indicator in the sequence of stimulus indicators, a correlation betweenstimulus indicators in the window comprising the stimulus indicator and the predetermined number of adjacent stimulus indicators, andB-scan layers of the B-scan layers that are based on B-scans which have been generated by the OCT imaging device (200) while the retina (10) was being stimulated in accordance with the stimulus indicators in the window; andthe response generator module (125-7) is configured to generate the indication of the response of the retina (10) to the light stimulus by generating, for each of the at least one sequence of concatenated B-scan layers, an indication of a response of a layer of the retina (10) corresponding to the sequence of concatenated B-scan layers to the light stimulus, by combining the calculated correlations.E31. The apparatus (100-7) according to E30, whereinthe correlation calculator module (120-7) is configured to calculate, as the rolling window correlation for each of the at least one sequence of concatenated B-scan layers, a respective three-dimensional array of combined correlation values, each three-dimensional array of combined correlation values comprising one-dimensional arrays that have been calculated using sections of A-scans that are identically located in respective B-scans of the sequence of B-scans, andthe response generator module (125-7) is configured to generate the indication of the response to the light stimulus of a respective layer of the retina (10) corresponding to each of the at least one sequence of concatenated B-scan layers by:converting the three-dimensional array of combined correlation values to a two-dimensional array of combined correlation values by replacing each of the one-dimensional arrays of combined correlation values in the three-dimensional array with a respective single value that is an average of the combined correlation values in the one-dimensional array, the two-dimensional array of combined correlation values indicating the response of the retina (10) to the light stimulus as a function of location along the scanned region (R) of the retina (10) and time.E32. The apparatus (100-8) according to E20, wherein:the receiver module (110) is configured to receive a sequence of B-scans, which has been generated by the OCT imaging device (200) repeatedly scanning the scanned region (R) of the retina (10) over the time period, as the OCT image data;the apparatus (100-8) further comprises a B-scan processing module (118) configured to:segment each B-scan in the sequence of B-scans (500) into a plurality of B-scan layers so that each B-scan layer comprises respective sections of the A-scans forming the B-scan, and concatenate corresponding B-scan layers from the segmented B-scans to generate sequences of concatenated B-scan layers; andconvert each of at least one sequence of concatenated B-scan layers of the sequences of concatenated B-scan layers into a respective sequence of concatenated reduced B-scan layers, by replacing, for each B-scan layer in each of the at least one sequence of concatenated B-scan layers, the sections of the A-scans forming the B-scan layer with corresponding values of an average of A-scan elements in the sections of the A-scans;the correlation calculator module (120-8) is configured to calculate, for each of the at least one sequence of concatenated reduced B-scan layers, a respective rolling window correlation between the sequence of concatenated reduced B-scan layers and the sequence of stimulus indicators by calculating, for each stimulus indicator in the sequence of stimulus indicators, a correlation betweenstimulus indicators in the window comprising the stimulus indicator and the predetermined number of adjacent stimulus indicators, andvalues of the averages calculated using B-scan layers comprised in B-scans that have been generated by the OCT imaging device (200) while the retina (10) was being stimulated in accordance with the stimulus indicators in the window; andthe response generator module (125-8) is configured to generate the indication of the response of the retina (10) to the light stimulus by generating, for each of the at least one sequence of concatenated reduced B-scan layers, an indication of a response of a layer of the retina corresponding to the sequence of concatenated reduced B-scan layers to the light stimulus, by combining the calculated correlations to generate a two-dimensional array of combined correlation values indicating the response of the layer of the retina (10) to the light stimulus as a function of location in the scanned region (R) of the retina (10) and time.E33. The apparatus (100-7;100-8) according to E31 or E32, whereinthe response generator module (125-7;125-8) is configured to generate the indication of the response to the light stimulus of each layer of the retina (10) corresponding to the at least one sequence of concatenated reduced B-scan layers by:converting the respective two-dimensional array of combined correlation values to a respective sequence of combined correlation values by replacing each one-dimensional array of combined correlation values in the two-dimensional array, which one-dimensional array indicates the response of the layer of the retina (10) to the light stimulus as a function of location in the scanned region (r) of the retina (10), with a single value that is an average of the combined correlation values in the one-dimensional array, the sequence of combined correlation values indicating a response of the layer of the retina (10) in the scanned region (R) to the light stimulus as a function of time.E34. The apparatus (100-7;100-8) according to E31 or E32, wherein each two-dimensional array of combined correlation values comprises a sequence of one-dimensional arrays each indicating the response of the respective layer of the retina (10) to the light stimulus as a function of location in the scanned region (R) of the retina (10), and wherein the response generator module (125-7;125-8) is configured to generate the indication of the response to the light stimulus of each layer of the retina (10) corresponding to the respective one of the at least one sequence of concatenated B-scan layers by:generating a normalised two-dimensional array of combined correlation values by subtracting the first one-dimensional array in the sequence of one-dimensional arrays from each remaining one-dimensional array in the sequence of one-dimensional arrays, the normalised two-dimensional array of combined correlation values indicating the response of the layer of the retina (10) to the light stimulus as a function of location in the scanned region (R) of the retina (10) and time.E35. The apparatus (100-7;100-8) according to E31 or E32, wherein each two-dimensional array of combined correlation values comprises an array of one-dimensional arrays each indicating the response of the respective layer of the retina (10) to the light stimulus as a function of location in the scanned region (R) of the retina (10), and wherein the response generator module (125-7;125-8) is configured to generate the indication of the response to the light stimulus of each layer of the retina (10) corresponding to the respective one of the at least one sequence of concatenated B-scan layers by:generating a normalised two-dimensional array of combined correlation values by calculating an array of averaged combined correlation values such that each averaged combined correlation value in the array of averaged combined correlation values is an average of the combined correlation values that are correspondingly located in the one-dimensional arrays, and subtracting the calculated array of averaged combined correlation values from each of the one-dimensional arrays in the array of one-dimensional arrays, the normalised two-dimensional array of combined correlation values indicating the response of the layer of the retina (10) to the light stimulus as a function of location in the scanned region (R) of the retina (10) and time.E36. The apparatus (100-7;100-8) according to E34 or E35, wherein the response generator module (125-7;125-8) is configured to generate the indication of the response to the light stimulus of each layer of the retina (10) corresponding to the at least one sequence of concatenated reduced B-scan layers by:converting the respective normalised two-dimensional array of combined correlation values to a respective sequence of combined correlation values by replacing each one-dimensional array of combined correlation values in the normalised two-dimensional array, which one-dimensional array indicates the response of the layer of the retina to the light stimulus as a function of location in the scanned region of the retina, with a single value that is an average of the combined correlation values in the one-dimensional array, the sequence of combined correlation values indicating a response of the layer of the retina (10) in the scanned region (R) to the light stimulus as a function of time.E37. The apparatus (100-7;100-8) according to E33 or E36, further comprising:an image data generator module (130) configured to use the sequence of combined correlation values to generate image data defining an image that indicates the response of the layer of the retina (10) in the scanned region (R) of the retina (10) to the light stimulus as a function of time.E38. The apparatus (100-7;100-8) according to E37, wherein the image data generator module (130) is configured to use the one or more sequences of correlation values to generate an image which indicates at least one of:the response of the respective one or more layers of the retina (10) in the scanned region (R) to the light stimulus as a function of time;one or more properties of a respective one or more curves defining the response of the respective one or more layers of the retina (10) in the scanned region (R) to the light stimulus as a function of time; anda spatial variation, in the scanned region (R) of the retina (10), of one or more properties of the respective one or more curves defining the response of the respective one or more layers of the retina (10) in the scanned region (R) to the light stimulus as a function of time, the spatial variation being overlaid on an en-face representation of at least a portion the retina (10) which includes the scanned region (R).E39. The apparatus (100-1to100-8) according to any of E1 to E38, wherein the light stimulus comprises a light stimulus providing illumination over a whole visual field of the subject.E40. The apparatus (100-1to100-8) according to any of E1 to E39, wherein the sequence of stimulus indicators indicates a random or pseudo-random stimulation of the retina (10) over time.E41. The apparatus (100-1to100-8) according to any of E1 to E40, wherein each stimulus indicator in the sequence of stimulus indicators is indicative of whether or not the retina (10) was stimulated by the light stimulus, or a change in stimulation of the retina (10) by the light stimulus, in a respective time interval of the sequence of time intervals that spans the time period (T). In the foregoing description, example aspects are described with reference to several example embodiments. Accordingly, the specification should be regarded as illustrative, rather than restrictive. Similarly, the figures illustrated in the drawings, which highlight the functionality and advantages of the example embodiments, are presented for example purposes only. The architecture of the example embodiments is sufficiently flexible and configurable, such that it may be utilized (and navigated) in ways other than those shown in the accompanying figures. Software embodiments of the examples presented herein may be provided as a computer program, or software, such as one or more programs having instructions or sequences of instructions, included or stored in an article of manufacture such as a machine-accessible or machine-readable medium, an instruction store, or computer-readable storage device, each of which can be non-transitory, in one example embodiment. The program or instructions on the non-transitory machine-accessible medium, machine-readable medium, instruction store, or computer-readable storage device, may be used to program a computer system or other electronic device. The machine- or computer-readable medium, instruction store, and storage device may include, but are not limited to, floppy diskettes, optical disks, and magneto-optical disks or other types of media/machine-readable medium/instruction store/storage device suitable for storing or transmitting electronic instructions. The techniques described herein are not limited to any particular software configuration. They may find applicability in any computing or processing environment. The terms “computer-readable”, “machine-accessible medium”, “machine-readable medium”, “instruction store”, and “computer-readable storage device” used herein shall include any medium that is capable of storing, encoding, or transmitting instructions or a sequence of instructions for execution by the machine, computer, or computer processor and that causes the machine/computer/computer processor to perform any one of the methods described herein. Furthermore, it is common in the art to speak of software, in one form or another (e.g. program, procedure, process, application, module, unit, logic, and so on), as taking an action or causing a result. Such expressions are merely a shorthand way of stating that the execution of the software by a processing system causes the processor to perform an action to produce a result. Some embodiments may also be implemented by the preparation of application-specific integrated circuits, field-programmable gate arrays, or by interconnecting an appropriate network of conventional component circuits. Some embodiments include a computer program product. The computer program product may be a storage medium or media, instruction store(s), or storage device(s), having instructions stored thereon or therein which can be used to control, or cause, a computer or computer processor to perform any of the procedures of the example embodiments described herein. The storage medium/instruction store/storage device may include, by example and without limitation, an optical disc, a ROM, a RAM, an EPROM, an EEPROM, a DRAM, a VRAM, a flash memory, a flash card, a magnetic card, an optical card, nanosystems, a molecular memory integrated circuit, a RAID, remote data storage/archive/warehousing, and/or any other type of device suitable for storing instructions and/or data. Stored on any one of the computer-readable medium or media, instruction store(s), or storage device(s), some implementations include software for controlling both the hardware of the system and for enabling the system or microprocessor to interact with a human user or other mechanism utilizing the results of the example embodiments described herein. Such software may include without limitation device drivers, operating systems, and user applications. Ultimately, such computer-readable media or storage device(s) further include software for performing example aspects herein, as described above. Included in the programming and/or software of the system are software modules for implementing the procedures described herein. In some example embodiments herein, a module includes software, although in other example embodiments herein, a module includes hardware, or a combination of hardware and software. While various example embodiments have been described above, it should be understood that they have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant art(s) that various changes in form and detail can be made therein. Thus, the present invention should not be limited by any of the above described example embodiments, but should be defined only in accordance with the following claims and their equivalents. Further, the purpose of the Abstract is to enable the Patent Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The Abstract is not intended to be limiting as to the scope of the example embodiments presented herein in any way. It is also to be understood that the procedures recited in the claims need not be performed in the order presented. While this specification contains many specific embodiment details, these should not be construed as limiting, but rather as descriptions of features specific to particular embodiments described herein. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. Having now described some illustrative embodiments and embodiments, it is apparent that the foregoing is illustrative and not limiting, having been presented by way of example. In particular, although many of the examples presented herein involve specific combinations of apparatus or software elements, those elements may be combined in other ways to accomplish the same objectives. Acts, elements and features discussed only in connection with one embodiment are not intended to be excluded from a similar role in other embodiments or embodiments. The apparatus and computer programs described herein may be embodied in other specific forms without departing from the characteristics thereof. The foregoing embodiments are illustrative rather than limiting of the described systems and methods. Scope of the apparatus and computer programs described herein is thus indicated by the appended claims, rather than the foregoing description, and changes that come within the meaning and range of equivalency of the claims are embraced therein.

11857258

DESCRIPTION OF THE PREFERRED EMBODIMENTS It is noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless expressly and unequivocally limited to one referent. Within the following description the terms horizontal and vertical are relative to the conventional position of the subject's eyes/vision, regardless of the subject's actual head position, unless otherwise stated. Namely the subject's eyes and the center of the subject's vision will generally lie upon a horizontal plane (discounting variations in subject eye position for defining these reference directions). The vertical direction is perpendicular to the horizontal extending generally in the plane including the subject's chin and the top of their head. Regarding to the subject invention, there is mounting evidence to support the theory that vergence dysfunction contributes to disability after mTBI. Similarly there is mounting evidence to support the theory that vergence recovery is an important aspect in mTBI convalescence. The platform or system100of the present invention may be categorized as a type of Video-oculography (VOG) system. VOG systems have been defined by Richard E. Gans, PhD, who is the Founder and Executive Director of the American Institute of Balance and he served on the board of the American Academy of Audiology, in the Hearing Journal: May 2001—Volume 54—Issue 5—pp 40, 42 “Video-oculography is a method of recording eye movement through the use of digital video cameras. This is a significant change from electronystagmography, which uses the corneal retinal potential, which is the eye's battery-like effect. As the eyes move side to side and up and down, the corneo-retinal potential's positive and negative discharge is recorded. VOG technology, however, uses infrared cameras to measure the eye's position. Small cameras, mounted in goggles, track the center of the pupil to provide the location of the eye.” Specifically the platform is formed on the I-Portal®-PAS (Portable Assessment System, manufactured and supported by NKI Pittsburgh), a portable 3D head mounted display (HMD) system with integrated eye tracking technology. This technology is unique because it tests oculomotor and vergence function in an entirely virtual environment. Videonystagmograpy (VNG) is often defined as a technology for testing inner ear and central motor functions, a process known as vestibular assessment and is defined as involving the use of infrared cameras to trace eye movements during visual stimulation and positional changes. A VNG unit is typically a diagnostic system for recording, analyzing and reporting (generally) involuntary eye movements, called nystagmus for involuntary movements, using video imaging technology. The eye tracking unit100, as described in greater detail below, may also be defined as a VNG system100. VNG systems100are considered, for the purpose of this application, to be a subset of the broader VOG terminology FIG.1is a schematic view of the dynamic vergence testing platform or system100including 3d head mounted display system10with integrated eye tracking technology for objective testing of vergence dysfunction for diagnosis and vergence recovery for convalescence. The system100includes the head mounted goggle unit10, user input device30, headphones40for auditory input for instructions or stimulus and/or subject isolation, coupled to a laptop50to yield a highly portable system. The VOG/VNG system100is coupled to the subject and configured to present a plurality of virtual reality based visual stimulus to the subject, at least one visual stimulus providing a target stimulus for a visual based neurologic vergence testing. The system100is designed to obtain objective physiologic response of the subject from the eye tracking unit based upon the neurologic vergence test associated with each vergence visual stimulus presented to the subject. The system100is configured to use the objective physiologic responses to the neurologic vergence tests to diagnose the presence of traumatic brain injury. Virtual environment exposure, also called virtual reality or VR, has proven highly efficient and effective in vestibular rehabilitation since the experience gained during VR exposure is transferable to the real world. The VR technology in the present invention is used to provide a visual target for performing a variety of vergence neurologic tests on the subject. Additionally, the VR use in the rehabilitation of TBI accelerates the compensation of an acute loss of peripheral or central vestibular function by improving adaptive modifications of the vestibulo-ocular reflex. The portable system100has the potential of being used bedside and in the home to increase rehabilitation compensation speed and degree. FIG.2is a schematic design of head mounted VOG/VNG goggle unit10with OLED micro display or VR screen12, two sets of optics14, cameras16for recording eye movement typically at above 100 hz for vergence testing, micro LEDs18for illumination of the eyes, and a hot mirror. Simply, the VR screen12provides the visual stimulus and the cameras16capture eye response for quick analysis. The details of the VR display screen12are believed to be known to those or ordinary skill in the art and it allows the system100to present visual images or targets to the user that have a perceived or simulated distance for vergence testing. The eye tracking technology described herein, outside of the vergence testing described herein, is generally known in the art, and the camera based eye tracking goggle based unit10may use the IPORTAL® brand goggle based eye tracking cameras and software available from the assignee of this invention. The combination of the eye tracking and the display of simulated distanced visual targets allow the VOG/VNG system100to automatically run a number of preprogrammed neurologic vergence tests and to record the physiologic responses thereto. Although generally known in the art,FIG.3schematically illustrates the creation of a target25for vergence testing in the unit10in which the screen12is divided into a left eye vision field22and a right eye vision field23. The actual movement, for example along path27, of the target stimuli25in the two fields22and23is presented separately to each eye. The target25moves horizontally outward (left in the left field, rightward in the right field) simultaneously, or inward (both toward the nasal center line), with respect to any fixed position in the two fields22and23. This movement creates the perception of virtual depth, and when tracked by the two eyes, creates convergence and divergence eye movements for vergence testing. FIG.4schematically illustrates a background24used to facilitate vergence testing in the head mounted display10of the vergence testing platform100of the invention, wherein to enhance the subjective experience of depth, and thereby increase the likelihood of subjects responding with appropriate convergence and divergence eye movements, stimuli25will be presented in the context of background stimuli24that will themselves appear as 3 dimensional objects that surround or encompass or otherwise orient the target stimulus in a virtual 3 dimensional space. For instance, the target25can move within a square tunnel24that has virtual depth. The background square tunnel25will have slight differences in the two images in the two fields22and23, with increasing disparity near the center, which better creates the perception of a field that is farther from the viewer in the center than near the edges. Additionally the present invention contemplates the use of varying the size of the target25, in order to maintain perspective and to simulate the normal reduction in size of distant objects relative to closer objects. FIG.5schematically illustrates vergence testing physiology. The device10will present stimuli forming target25to each eye120(in this figure), each controlled independently, to simulate varying depth targets25. Targets25can be, for instance, single dot targets, images, or any other visual stimulus that may be rendered on the screen12. Through the varying of the horizontal shift of each eye's targets independently, an impression of varying depth is created for the target25as the subject converges their eyes120(see right eye position or trace130and left eye position or trace140) on the independent targets and fuses the two images into a perceived single image or target25. This is generally well known standard practice for creating virtual depth in a VR environment of the screen12. The VR stimulus software for performing the tests of the present invention is integrated into existing vestibular/neurological software for protocol setup, test results analysis, and to create VR stimulus25. Disparity Fusion (Vergence Saccade) Testing One vergence test, the representative results of which are shown inFIG.6, of the present invention will present targets25at different virtual depths in a punctuated fashion (sudden shifts in target position followed by delays where the targets are stationary), which are referred to here as Vergence Step, or vergence saccade or disparity fusion. This saccadic vergence stimulus25pattern will encourage subjects to make responsive convergence/divergence eye movements (schematically represented in traces130and140) to fuse the stimuli25into a single perceived image or target25and then hold that vergence position until the next stimulus change. This disparity fusion test can be summarized as where subjects visualize the stimulus25moving towards and away from them in a saccadic manner. The following variables were our key measures: Left and right eye Decay time (also called response time), Symmetry of left and right eye movement, Amplitude of-Eye movement, and % of saccade. The I-Portal google system from Neurokinetics is sufficient for this testing, however for other platforms the sampling rate of the eye images should be 100 hz (or higher) with a resolution of <0.1°. The testing platform18was designed to track18variables associated with specific physiologic responses for this test, with the major variables being noted, however any desired variable may be tracked if the system10contains sufficient information. For example measurements of the maximum left and right eye acceleration will be subject to the restraints of the sampling rate. For Vergence Step testing, data will be segmented so that each segment or cycle is the eye response to a target25shift. Measures will be derived both for individual segments and for the testing data as a whole. The following are examples of measures that will be generated by the method or device for Vergence Step testing, both per segment and for the whole test: The correlation between the movement of the two eyes in response to the target shift, where “correlation” could be any new or standard method of measuring how the two eye signals are alike, or co-vary (examples: Pearson's correlation, Kendall's Tau, Spearman, or any form of cross-correlation, e.g., correlations at different respective offsets of the two signals); The presence and amount of saccadic movement (which is distinct from vergence movement), The time for each eye to respond to target change and reach a steady position, The magnitude of the vergence movement of each eye, and The asymmetry, between the two eyes, of any of the previous three measures (saccades, time, magnitude). FIG.6specifically is a graph of an mTBI subject and a control subject response to a vergence saccade test performed on the head mounted display10of the vergence testing platform100ofFIG.1. Specifically the mTBI subject was a 20 year old female with the testing performed 2 days after she sustained the injury causing her mTBI. The upper graph shows the position of the target or stimulus25jumping between two positions with the trace of the mTBI subject's right eye130and left eye140shown. This evidences the abnormal state in which the left and right eyes are moving in parallel with a symmetry, specifically the inward symmetry (comparison of left to right eye movement in response to presentation of the target25at the position “closest” to the subject) of the mTBI subject was 0.71 and the outward symmetry (comparison of left to right eye movement in response to presentation of the target25at the position “farthest” to the subject) of the mTBI subject was 0.88. This is also described as conjugate motion. The lower graph shows the position of the target or stimulus25jumping between the same two positions as the upper graph (as it is the same test) with the trace of the control subject's right eye130and left eye140shown. The control subject was a 32 year old male whose response evidences the generally normal state in which the left and right eyes are moving in opposition to each other with a symmetry of at or near −1.0, specifically the inward symmetry (comparison of left to right eye movement in response to presentation of the target25at the position “closest” to the subject) of the control subject was −0.97 and the outward symmetry (comparison of left to right eye movement in response to presentation of the target25at the position “farthest” to the subject) of the control subject was −0.91. This is also described as disconjugate motion. A normal symmetry result for this test approaches −1.0 while abnormal symmetry for this test is typically above 0. FIG.11shows a summary of results from subjects of this saccadic vergence test. In this particular sample there were 58 control subjects analyzed, specifically 42 males (72.4%) and 16 females (27.6%), ranging in age from 22-45 with a mean of 30.5 years (SD 6.8 years). Additionally in this sample there were 17 total concussed subjects analyzed, specifically 13 males (76.5%) and 4 females (23.5%), ranging in age from 20-43 with a mean of 29.1 years (SD 8.1 years. All mTBI subjects and controls were tested at three sites: University of Miami Miller School of Medicine; Madigan Army Medical Center; and Naval Medical Center San Diego. All mTBI subjects were diagnosed with mTBI by an emergency room physician. mTBI subjects tested using the following time line: 24-48 hours post injury; 1 week post injury and 2 weeks post in jury. All control subjects were tested one time. FIG.7is a graph of an mTBI subject and a control subject average eye response over multiple trials to the vergence saccade test ofFIG.6. In this graph the mTBI subject is a 25 year old female with the test undertaken 2 days post injury. The control is a 30 year old female.FIG.8is a chart of mTBI subject and control subject decay times (a measure of response) and amplitudes to the vergence saccade test ofFIG.6and the test subjects shown inFIG.7. It is readily apparent that the curves are different between the two subjects in how closely they match the graph of NL physiologic response150. As seen in the table ofFIG.8, significantly higher values for decay time and significantly lower values for eye amplitude were seen in both inward and outward target movement for the mTBI subject compared to the control subject Vergence Smooth Pursuit Testing Another vergence test of the method or device100will present a continuously, smoothly transitioning movement of the stimuli25, creating the appearance of a target25gradually moving toward or away from the subject in the virtual depth space. This will encourage subjects to make continually updated, smoothly transitioning convergence and divergence movements. Here we refer to this as “Vergence Pursuit” or vergence smooth pursuit. For the vergence smooth pursuit test, subjects visualized the stimulus25moving towards and away in a sinusoidal pattern at 0.1 Hz. The following variables were determined to be key variables for analysis, namely Near and far angle (measures of the angle of the left and right eye with the target25at the nearest point and the farthest point, respectively, in its sinusoidal movement), Excursion (a measure of the difference between the near and far angle, or an amplitude measurement), Lag time (a measure of the delay between target movement and tracking eye movement) and Symmetry (a measure of the comparison of the left and the right eye movements). For Vergence Pursuit testing, data will be both segmented into individual cycles (sub-segments of the target movement profile, e.g., cycles of a sinusoidally-modulated stimulus) and analyzed per cycle, or analyzed for the whole test. The following are examples of measures that will be generated by the method or device for Vergence Pursuit testing, both per cycle and for the whole test: The correlation between the movements of the two eyes during target presentation (where “correlation” or symmetry is as defined for Vergence Step testing above); The lag (temporal shift) of the eye movement relative to the virtual position of the stimulus; The amplitude or gain of the eye position relative to the virtual position of the stimulus at any or all time points during the test; The presence and amount of saccadic movement during the test; and The asymmetry, between the two eyes, of any of the previous three measures (saccades, lag, gain). FIG.9is a graph of an mTBI subject and a control subject responses to a vergence smooth pursuit test performed on the head mounted display10of the vergence testing platform100ofFIG.1.FIG.10is a chart of summary of results of the mTBI subject and control subject eye responses to the vergence smooth pursuit test ofFIG.9. Specifically the mTBI subject was a 20 year old female with the testing performed 2 days after she sustained the injury causing her mTBI, while the control was a 32 year old male. A cursory review of the two graphs makes clear that the eye movement (curves) between the two subjects are quite different. Note in the table, the near normal symmetry value of the control subject approaching −1.0 (−0.91) compared to the mTBI subject's value greater than +0.9. Additionally, small lag values are seen for the control subject while significantly larger values are seen in the mTBI subject. FIG.11is a chart summarizing symmetry results for mTBI subjects and control subjects for a series of vergence testing performed on the head mounted display of the vergence testing platform ofFIG.1. Analysis of variance noted a high degree of vergence symmetry deficits in the mTBI group that were not present in the control group with p values less 0.001 for both disparity fusion symmetry and vergence smooth pursuit symmetry. Logistic regression analysis of this data for both vergence tests shown inFIGS.12and13demonstrated that abnormalities were virtually non-existent in control subjects and present in about half of mTBI subjects. A 95% confidence interval for symmetry values in control subjects fell in the range of −1.0 to −0.87. The presence of any vergence abnormalities in the testing paradigm was largely diagnostic of mTBI, in other words abnormal results were essentially only seen in mTBI subjects.FIGS.12and13are charts summarizing linear regression analysis as a predictor of mTBI using the results of the vergence testing performed on the head mounted display of the vergence testing platform ofFIG.1. FIG.14is a chart of smooth pursuit vergence testing symmetry of four mTBI subjects over a two week period using the results of the smooth pursuit vergence testing performed on the head mounted display of the vergence testing platform ofFIG.1. As shown inFIG.14, significant improvement in results compared with control levels was exhibited in these subjects over a two week period. Vergence deficiencies can be objectively measured and characterized using the portable, 3D head mounted display system100with integrated eye tracking technology. Characterizing vergence function in healthy controls and pathologic dysfunction in mTBI patients as evidenced herein is an additional tool in the management and study of individuals with mTBI. Vergence data may be used as a tool in the diagnosis of mTBI and return to activity decision making. Objective Measurement of Minimal Vergence Angle (Minimal Vergence Distance) The vergence testing platform100ofFIG.1using the smooth pursuit vergence testing provides for objective measurement of minimal vergence angle or minimal vergence distance. The minimal vergence angle or minimal vergence distance is the point where the subject's eyes no longer resolve a single target such that the subject generally will begin to see two stimuli. The minimal vergence angle is the angle of the eye at this point and will correspond to a minimal vergence distance in front of the subject. In prior art mechanical vergence systems the subject may be prompted to indicate when they see two stimuli or targets as a target is advanced toward the subject in order to attempt to measure this physiologic parameter of minimal vergence angle or distance. In the present platform100, the subjects eye responses throughout the above smooth pursuit vergence testing can be tracked and eye oscillations above a threshold can be used as an indication of the subject reaching minimal vergence angle. The platform yields an objective measure for this physiologic parameter. Offset Vergance Testing A further variation to the first two tests is the alignment of the target25. In the illustrated example above the target25is virtually aligned between the two eyes, generally a standard in vergence testing, and the movement is along a horizontal line (Line of Testing). In the present invention, either of the first two tests (VERGENCE SMOOTH PURSUIT and VERGENCE SACCADE) may have the alignment of the Line of Test shifted from this center position. Of particular interest is an alignment of the Line of Test of the test target25with one or the other eye (e.g., a horizontal offsetting of the location of the Line of Test of the test target25from the center location) and performing the vergence smooth pursuit and vergence saccade type vergence testing with a Line of Test aligned with one or the other eye. Such an eye aligning offsetting of the Line of Test will greatly affect the normal symmetry for either the vergence smooth pursuit and the vergence saccade type vergence testing, but such placement can increase the magnitude of results for one of the eyes, such as the near and far angle of the eye that is not aligned with the target25. This can be particularly helpful in obtaining objective measurements for the objective measurement of minimal vergence angle for each eye independently of the other. The performance of the vergence testing with the Line of Test positioning aligned with one eye can also isolate other issues with results from the aligned eye. For example if the eye that is aligned with the target25jumps off target25with a saccadic movement, then it is not the aligned eye's vergence movement that in error as no eye movement was necessary for at least that eye in this movement. These modifications of the vergence smooth pursuit and vergence saccade type vergence testing are called offset vergence testing. This type of offset vergence testing yields improved assessment of subject thresholds and better comparisons of left and right eye disparities. Vertically Adjusted Vergance Testing The adjustment of the horizontal Line of Test for vergence smooth pursuit and vergence saccade type vergence testing along a horizontal plane forms the offset vergence testing described above and is useful for isolating single eye movements as discussed above. The present invention further provides for adjustment or movement of the horizontal Line of Test for vergence smooth pursuit and vergence saccade type vergence testing from the conventional center positon along a vertical plane forms a distinct testing known herein as Vertically Adjusted Vergence Testing. Performing Vertically Adjusted Vergence Testing, both above and below the center of vision, can be used to enhance measured discrepancies between left and right eye movements of the subject. Typical vertical adjustment would be expected to be at least 10 degrees above or below center to yield significant additional physiologic parameters for the subject. The Vertically Adjusted Vergence Testing can be combined with the offset vergence testing described above to have the horizontal Line of Test for vergence smooth pursuit and vergence saccade type vergence testing aligned along a vertical plane through a subject's eye but adjusted above or below the center of vision, however the alignment no longer eliminates the eye movement of the aligned eye in such testing due to the inclusion of the vertical offset of the line of test. Full 3-Dimensional Vergence Testing The vergence testing on the platform100is not limited to the specific examples discussed above in which the target25movement along the Line of Test within a vergence test is maintained within a general horizontal line. A further vergence test of the method or device100will present either of the vergence smooth pursuit and vergence saccade type vergence testing in combination with additional horizontal and/or vertical movement that will create the impression of a target25that moves both in depth relative to, and in position within the visual plane (i.e. this will create a target25that moves virtually in all three dimensions). In short the Line of Test is no longer in a horizontal line extending ONLY toward and away from the subject. The Line of Test may be angled up or down or sideways. Further the Line of Test need not be a straight line but could form a curved trace or even a loop shape. This form of testing is referred to herein as “Full 3-Dimensional Vergence”. As one example instance, a test could be presented in which the target moves smoothly along a virtual trajectory through all 3 spatial dimensions, tracing a circle, ellipse, spiral, or any other trajectory that is at any angle to the visual plane, or that continuously changes angle relative to the visual plane. Objective Testing of Vergence Dysfunction The above described invention provides an objective testing of vergence dysfunction comprising the steps of: providing a head mounted goggle based stimulus generating eye tracking unit to the subject; presenting visual stimulus to the subject, wherein the visual stimulus is in the head mounted goggle based system and forms the optical target stimulus for at least one vergence test; obtaining objective physiologic response of the subject from the head mounted goggle unit based upon each of the visual stimulus presented to the subject in each test; and using the objective physiologic responses to diagnose the presence of vergence dysfunction. A portable objective testing platform for vergence testing100may be summarized as including a laptop50; and a head mounted goggle based stimulus generating eye tracking unit10coupled to the laptop50, the unit10including a VR screen12and two cameras16for recording eye movement, wherein the VR screen12is configured to present visual stimulus25to the subject, wherein the visual stimulus25is in the head mounted goggle based system10and forms the optical target stimulus25for at least one vergence test, and wherein the cameras16are configured to obtain objective physiologic responses of the subject from the head mounted goggle unit10based upon each of the visual stimulus25presented to the subject in each test. Vergence Recovery Convalescence Another aspect of the present invention is the provision of vergence recovery convalescence using the dynamic vergence testing platform100including 3d head mounted display system10with integrated eye tracking technology comprising the steps of: A. providing a head mounted goggle based stimulus generating eye tracking unit10to the subject; B. presenting visual stimulus25to the subject, wherein the visual stimulus25is in the head mounted goggle based system10and forms the optical target stimulus25for at least one vergence test; C. obtaining objective physiologic response of the subject from the head mounted goggle unit10based upon each of the visual stimulus25presented to the subject in each test; and D. Presenting at least select physiologic response to the subject; and E. Repeating steps B-D. Subjects with vergence dysfunction are greatly aided when the nature of the dysfunction is explained and they have an opportunity to “work” on the identified deficiency in the course of further vergence testing. The offset vergence testing protocols described herein may be particularly well suited for isolating the eyes requiring the work to facilitate convalescence using the dynamic vergence testing platform100. Once a deficiency is noted the subject can be given threshold for a given deficiency in a given test with the testing protocol repeated until the subject reaches the given threshold for the session (or lack of improvement is noted after a given testing time). A new threshold is set for subsequent sessions. The positive feedback of reaching improved results can facilitate subject gains over time. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications that are within the spirit and scope of the invention, as defined by the appended claims and equivalents thereto. The preferred embodiments described above are illustrative of the present invention and not restrictive hereof. It will be obvious that various changes may be made to the present invention without departing from the spirit and scope of the present invention. The precise scope of the present invention is defined by the appended claims and equivalents thereto.

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DETAILED DESCRIPTION In the following detailed description, for purposes of explanation and not limitation, example embodiments disclosing specific details are set forth in order to provide a thorough understanding of an embodiment according to the present teachings. However, it will be apparent to one having ordinary skill in the art having had the benefit of the present disclosure that other embodiments according to the present teachings that depart from the specific details disclosed herein remain within the scope of the appended claims. Moreover, descriptions of well-known apparati and methods may be omitted so as to not obscure the description of the example embodiments. Such methods and apparati are clearly within the scope of the present teachings. FIG.1illustrates a portion of an example embodiment of an automated non-contact eye examination instrument or apparatus1000for performing an eye examination of one or both eyes15of a patient or subject10. Apparatus1000includes a housing1100. As described in greater detail below, housing has an aperture1110for providing light to and from one or more internal optical systems and one or both eyes15of subject10while subject10is separated and spaced apart from housing1100and while eye15is not maintained in a fixed positional relationship with respect to housing1100. Here, an aperture may be defined as a space through which light passes between instrument or apparatus1000and one or both eyes15of subject10. In some embodiments, aperture1110may comprise a hole or opening in housing1100. In some embodiments, aperture1110may comprise a protective, light-transmissive or transparent, window through which light passes to and from one or more internal optical systems and one or both eyes15of subject10. Beneficially, the external surface of housing1100is smooth, allowing for quick and easy disinfection. Beneficially, the external surface of housing1100conforms to3A sanitary standards. In some embodiments, housing1100is provided with protective side shields1120. In some embodiments, an external surface of housing1100may be fabricated of, and/or coated with, an anti-microbial material. Apparatus1000further includes: cameras1200; at least one optical system1300; an optical system movement arrangement1400; an eye chart1500as a target for eye(s)15of subject10; and a mirror system1600disposed in an optical path between eye15of subject10and the eye chart1500. Mirror system1600lengthens an optical path between eye(s)15of subject10and eye chart1500, effectively providing a viewing lane for subject10to view eye chart1500, and accordingly may be referred to as a lane mirror arrangement. In some embodiments, apparatus1000may include two optical systems; one for each of the two eyes15of subject10. In some embodiments, apparatus1000may include two optical system movement arrangements1400; one for each optical system1300for each of a subject's two eyes15. In other embodiments, apparatus1000may include one optical system movement arrangement1400which moves two optical systems1300. FIG.2illustrates another portion of an example embodiment of an automated non-contact eye examination apparatus2000. Eye examination apparatus2000may be one embodiment of eye examination apparatus1000ofFIG.1.FIG.2illustrates that eye examination apparatus2000includes optical system1300, a processing system2200, electronics2300, a display device2400, a speaker2500, a motor2610and a pulley2620. As withFIG.1, automated non-contact eye examination apparatus2000may include two optical systems; one for each of the two eyes15of subject10. Processing system2200may include one or more processors and memory, including volatile and/or non-volatile memory. The memory may store therein instructions which may be executed by the one or more processors to execute any of the various algorithms or methods disclosed below. Motor2610and pulley2620may comprises one embodiment of optical system movement arrangement1400ofFIG.1. As shown inFIG.2, eye examination apparatus2000may communicate to one or more external remote terminals via Internet50. To that end, electronics2300may include a communication device (not shown) which may be wired and/or wireless and may communicate via WiFi, a wired Internet connection, a wireless mobile network (e.g., 4G or 5G), etc. Some of the significant features of eye examination apparatus1000include the easily disinfected smooth outer shell or housing1100and the notable absence of the traditional headrest for subject10. Eye measurement apparatus1000provides light to and from optical system1300and eye15of subject10while subject10is separated and spaced apart from housing1100and while eye15is not maintained in a fixed positional relationship with respect to housing1100. That is, in contrast to traditional ophthalmic instruments, eye examination apparatus1000does not require the head of subject10be constrained for eye measurements. Instead, eye examination apparatus1000includes an automatic eye tracking arrangement which is configured to ascertain a current positional relationship of eye15with respect to optical system1300(beneficially without human assistance), and in response thereto to control optical system movement arrangement1400to move optical system1300into a predetermined positional relationship with respect to eye15(again, beneficially without human assistance). The embodiment illustrated inFIG.1uses multiple cameras1200to automatically and continuously align the internal measurement modules (e.g., optical system1300) of eye examination apparatus1000to eye(s)15of subject10during the measurements, regardless of normal subject motion. This concept eliminates the need for subject10to contact any surfaces of eye examination apparatus1000, or to be in proximity to a technician during the measurements. Subject10does not even need to sit to have an eye examination. Inside outer shell1100, the use of spatial light modulators, a multi-function optical train, structured lighting, and head/eye tracking hardware may coordinate to provide subject10an experience that an eye examination is as simple as reading eye chart1500. The optical paths for all measurements include a sufficiently large standoff, DSTANDOFF, to allow all measurements to take place with subject10standing comfortably distant from the protective window of aperture1110. The eye measurement system may be capable of video rate captures of eye images and refraction measurements. Beneficially eye examination apparatus1000has a small footprint which allows multiple eye examination apparati1000to be co-located in the typically small examination rooms found in eye clinics. Audio/visual cues may be provided to the patient by the eye examination apparatus1000and/or remotely by a technician or physician prior to, during, and/or after the eye examination. The added optional feature of a remote telemedical connection may allow eye examination apparatus1000to be conveniently located at places where it can be easily accessed by patients or subjects, by pre-arranged appointment, during the course of their normal workday activities. In the United States, a complete eye examination requires the measurements and assessments shown in Table 1 below. Note that the Intraocular Pressure measurement is conducted to detect early-stage glaucoma, which may also be detected through fundoscopic examination. TABLE 1Test/FunctionModuleReason/DiagnosisObjective RefractionAuto-refractorDetect uncorrected refractive errorSubjective RefractionPre-CompensatorRefine refraction for prescriptionVisual AcuityEye DisplayTests spatial frequency response of centralvisual fieldPupil FunctionEye ImagerTests eye monocular and binocular eyeresponse to lightConfrontation VisualEye ImagerTests peripheral visual system response toFieldsmoving objectsExtraocular motilityEye ImagerTests stability of fixation and ability toand alignmentsmoothly track objectsExternal (anterior)Eye ImagerDetects pathologies of the eyelids and tissuesExaminationsurrounding the eye, e.g., trachomaSlit Lamp ExamEye ImagerDetects pathologies in the anterior segmentand cornea, e.g., corneal opacity, cataractFundoscopicFundus ImagerDetects pathologies of the retina, e.g.,Examinationage-related macular degeneration,diabetic retinopathyIntraocular PressureTonographerDetects glaucoma In some embodiments, eye measurement apparatus1000is capable of performing all of the measurements and assessments listed in Table 1. In some embodiments, eye examination apparatus1000is capable of conducting remote refraction measurements without the presence of a technician, thus enabling corrective prescriptions for eyeglasses or contact lenses to be dispensed by a HCP immediately. FIG.3illustrates an embodiment of an eye measurement system3000which may be included in an eye examination apparatus such as eye examination apparatus1000. Eye measurement system3000includes a lane mirror system and an optical system3500, comprising optical devices and elements forming an optical path for eye measurement system3000. Optical system3000is a specific embodiment of optical system1300ofFIGS.1and2. FIG.4illustrates an example embodiment of an optical system3000comprising various light sources, sensors (or detectors), viewing targets, mirrors and other various optical elements forming an optical path for eye measurement system3000. Optical system3000is a specific embodiment of optical system3500ofFIG.3, and will be described in greater detail below. FIG.3shows the entire optical path including lane mirrors M3, M4, M5and M6, eye chart display device LS5. All lane mirrors may be mounted to housing1100so as to be stationary while LS5is mounted to optical system3500that is free to move both vertically and horizontally as necessary to align itself to eye15. The lane length is the optical distance between Image Plane2(shown inFIG.4) and LS5. LS5may be used to display traditional Snellen Eye Charts or similar targets upon which subject10may focus, as well as other icons or targets that may serve as fixation targets to manipulate the gaze angle of subject10. This optical arrangement allows the lane length to remain constant as optical system3500is translated vertically. The lane length may be comparable to that used in traditional clinical lanes; e.g., 3 m or longer. The lane mirrors are sufficiently wide (out of diagram plane) to reflect light from LS5onto Image Plane2(and thus eye15) regardless of the horizontal position of optical system3500. LS5serves as the far refraction target traditionally used to measure the distance refraction correction of eye15during subjective refraction; it also acts as the fixation target during objective refraction measurement. Additionally, the lane mirrors and LS5may serve both eyes15when eye examination apparatus1000is configured for binocular operation; such a configuration permits subject10to advantageously use convergence cues to perceive the target at full lane distance to reduce the likelihood of accommodation. An optional near target, LS6(as shown inFIG.4), may be mounted onto optical system3500at a distance 30-50 cm from Image Plane2; by translating mirror M7into the lane path, LS6provides a near target for subjective and objective measurement of the near refraction correction for eyes15suffering from presbyopia. Eye examination apparatus1000addresses two areas of critical importance that offer technical challenges: automated alignment and tracking of eye15required to achieve the needed optical alignment without contacting subject10; and providing an optical configuration which has a sufficient optical standoff to permit robust isolation of eye examination apparatus1000and subject10. Regarding the former, in the past eye alignment has typically required the head of subject10to be constrained while the eye measurement system is brought to the desired object plane and the x and y positions (e.g., pupil center). The object plane of the optical system is typically designed to be fixed focus relative to the body of the apparatus. Alignment is achieved by monitoring the x and y positions of a desired fiducial while the z position is adjusted to bring the image into focus. Once alignment is achieved, one or a few measurement images may be captured (e.g., Shack-Hartmann wavefront images). In contrast, for embodiments of the automated eye examination apparatus1000, subject10is not required to be constrained and is subject to motion in 6 dimensions: three positions and three angles. However, rather than design the automated alignment and tracking system to apply alignment corrections of eye examination apparatus1000in all dimensions, in some embodiments, variance is accommodated in the z dimension through proper optical design. In this case, optical system4000may be already constrained to the distal side of the protective window of aperture1110. This may be accomplished through a variable focus component. In some embodiments, alignment cameras1200are capable of detecting and measuring z distance, cyclo-rotation, and gaze angle variations which can be used to compensate the measurements or to filter images from the video stream that exceed the desired tolerances. Note that the interpupillary distance must also be considered in this binocular instrument, however, this distance only need be adjusted at the start of the measurement sequence. With these choices, an automatic eye alignment and tracking system simplifies to correcting only lateral (x) and vertical corrections (y) while measuring the remaining 4 dimensions. The angle ranges measured are further bounded by providing a visual target for eye15to look at while being measured. Deviations may occur from saccadic movements which can be detected and excluded when necessary. In optical system4000, eye tracking may be accomplished through the inclusion of a Light Detection and Ranging (“LIDAR”) device4100as described in greater detail below with respect toFIG.11. FIG.5illustrates another example embodiment of an eye alignment arrangement which incorporates cameras1200. This optical system uses two or more imaging cameras1200to provide 6-dimensional (e.g., x,y,z,α,β,χ) position and rotation information of the position of subject10relative eye examination apparatus1000to permit accurate, real-time alignment of optical system3500to subject10. Structured or unstructured lighting may optionally be supplied to improve the accuracy of the alignment. The two primary features to be tracked include the eye pupils. Cameras1200may be stationary with respect to eye examination apparatus1000, or may move with or independent of optical system3500. Cameras may optionally be equipped with prisms5100to increase the oblique angles that can be captured. Regarding the optical configuration, eye measurement system may include a variable phoropter/autorefractor, and an eye imaging arrangement including an imaging device (e.g., a camera) for imaging anterior and posterior segments of eye15. Manifest refraction is the gold standard for measuring refraction of eye15.FIG.6below illustrates an embodiment of eye examination apparatus which includes as a pre-compensation section6100a phoropter which comprises lenses that can be inserted into the line of sight of eye15while subject10views a distant object (e.g., Snellen eye chart at 4 meters distance). The physician may systematically vary the sphere value and the cylinder magnitude and axis while asking subject10to compare between lens combinations as to which is clearer. Such subjective refraction generally may be first done monocularly, but ultimately verified binocularly. To ensure that subject10has relaxed accommodation, additional plus lenses are often added to ensure the target becomes noticeably less focused. The lenses in the phoropter come in 0.25 Diopter increments, limiting the accuracy of measurement to what is typically achieved in eyeglasses and contact lenses. The repeatability of the measurement is limited to a standard deviation of 0.319 D by the subjective feedback and is highly dependent on the skill of the physician, particularly with respect to correcting the magnitude and axis of the cylinder component. FIG.6illustrates elements of an example embodiment of an autorefractor6000. Autorefractor6000includes, among other things, light source LS2, pre-compensation section6100, beam splitters6102and6104, a wavefront sensor6200, and lane mirror6300. In some embodiments, an autorefractor uses a Badal optometer as pre-compensation section6100through which subject10views an optical fixation target. The target is conveniently projected into eye15with a vergence at optical infinity or beyond (fogging) to stimulate subject10into relaxing accommodation as when viewing an actual object at a large distance. Light source LS2, having passed through the pre-compensation section and the anterior of the eye focuses onto the patient's retina and scatters backwards toward autorefractor6000. Sensor6200(e.g., a Shack-Hartmann wavefront detector, a phase diversity sensor, a pyramid sensor, a curvature sensor, a point spread function (PSF) sensor, a retro illumination refractometer, etc.) monitors the wavefront emanating from “guide star light” injected into eye15and scattering from the retina that passes through pre-compensation section6100, as discussed below with respect toFIGS.7-11. Calibrated pre-compensating section6100, such as a Badal optometer, in the sensing branch serves to subtract sphere and cylinder from the wavefront impinging on sensor6200such that it remains within its measurement range. The total wavefront from eye15is the sum of the pre-compensation values and the residual wavefront measured on sensor6200. With each successive measurement of the wavefront, the pre-compensation section6100may be adjusted to further reduce the wavefront curvature. This iterative process continues until the measured wavefront curvature it is within the desired tolerance; the process may then terminate and the final refraction reported. Measurement precision approaching 0.1 D is routinely obtained with properly designed autorefractors. While the auto refractor affords better precision than manifest refraction, traditional autorefractors seldom achieve the same level of accuracy as manifest refraction. The unnatural target projected at large optical distance does not effectively relax accommodation because other visual cues of distance are missing. In particular, the autorefractor is most often a monocular device that excludes convergence cues to distance; other cues can also make the subject perceive the target closer (e.g., looking into a small instrument or a small tube). These factors frequently lead to “instrument accommodation” that can amount to a large fraction of a diopter of error. The cylinder magnitude and axis, on the other hand, are very accurately measured by an autorefractor. In contrast to existing instruments, eye examination apparatus1000may support (simultaneous) manifest refraction and autorefraction measurements using the same optical system1300, and both can be combined to yield higher accuracy results. In some embodiments, autorefractor6000incorporates corrective lenses positioned at a variable optical standoff of 150-200 mm and a real, dynamically programmable target (on an electronic display) at a distance presented to the subject in binocular format. The distant real target mitigates “instrument accommodation” by subject10. While similar to the manifest refraction set up, this innovative approach raises challenges because the refractive correction is placed far from the normal spectacle plane (about 12.5 mm from eye vertex) where phoropter lenses would be placed and may introduce unwanted, unnatural optical distortions (e.g., tilt). Fortunately, the mathematics of ray tracing is well established, and these distortions can be modelled and corrected. The corrective power of this pre-compensation section can be remotely adjusted in response to feedback from subject10. The refractive measurement from the autorefractor may be advantageously used to initially adjust the pre-compensation section prior to manifest refraction. With the final correction in place, the HCP can conduct traditional subjective visual acuity testing much as they would with a phoropter, except that the lens adjustment for this scenario is electronically controlled. In this way the advantages of the accuracy of a phoropter and manifest refraction can be combined with the precision of the autorefractor. Indeed, eye examination apparatus1000may deliver both subjective refraction (manifest refraction) and objective refraction (autorefraction) measurements. FIG.7illustrates some principles of a pre-compensation section of an eye measurement system. The effective focal length, fcp, when located at the correction plane, at distance CP from eye15, for a target at distance Lane, will bring the target into best focus on the retina of the dis-accommodated eye15. Equation 1 below shows how the RoC, the radius of curvature of the wavefront at the corneal vertex, is related to fcp, CP, and Lane; RoC is positive for hyperopes, negative for myopes, and infinity for a true emmetrope. 1fcp=1RoC+CP+1Lane=RxcpEquation⁢⁢1 The measurement of RoC can be done at any convenient distance CP. Lane is typically >3 meters in most eye clinics. Given the RoC for each subject eye15, the physician prescribes refractive corrections, Rxcp, using Equation 1 with CP=0 for contact lenses and refractive surgeries, and to about 0.0125 meters for eyeglasses. The purpose of the pre-compensation section is to compensate the subject's refractive error (sphero-cylindrical) so the subject sees the target clearly. The effective focal length, fcp, of the pre-compensation section is adjusted to bring the target into focus when eye16is dis-accommodated. Dis-accommodation may be accomplished by manually fogging (as in manifest refraction) or with an interactive algorithm (as in autorefractors). When eye15is dis-accommodated and the sphero-cylindrical correction of the pre-compensation section has been adjusted to produce best focus of the target for the subject, the radius of curvature (RoC) of the wavefront meridians just outside the cornea can be determined mathematically. The measured RoCs can then be used to prescribe the appropriate sphero-cylindrical refractive correction (e.g., contact lenses, eyeglasses, or refractive surgery) for subject10. Various embodiments of pre-compensation may be accomplished with a variety of techniques. In its simplest embodiment, the pre-compensation section may comprise a collection of lenses much like in a phoropter. Other embodiments include the incorporation of variable power pre-compensation elements such as variable focal length lenses (e.g., liquid lenses), a wide angle Badal optometer that employs moving optics on linear stages, variable mirrors (e.g., adaptive optics deformable mirror), a phase only spatial light modulator, or a retroreflection refractor, or combinations of the above. In one such embodiment, a phase only spatial light modulator (SLM) may be coupled with helper lenses to the same effect but with higher speed and with the ability to pre-compensate cylinder at any axis. The SLM is capable of providing variable spherocylindrical correction over some dynamic range (e.g., ±5 D), which can be added to the helper lens(es) to span the relevant refractive correction range of human eyes (−16 to +8 D sphere, and 0 to −6 D cylinder). Like the variable power options which act to reduce the number of corrective lenses and mechanical complexity while improving the resolution of measurement below 0.25 diopters, the SLM introduces the ability to also correct for unwanted distortions such as tip/tilt as the subject moves laterally. These variable power options also can compensate for subject motion that introduces variations in the optical standoff which would otherwise affect the measurement. SLMs generally only supply about a 2π of phase delay but can do so at spatial resolutions approaching 4160(h)×2464(v) using 3.45 μm pixels at refresh rates approaching 60 Hz. With this density, it is possible to create a variable power Fresnel lens with sphero-cylinder power up to ±5 diopters over a 6 mm diameter aperture. Furthermore, the center of this correction can be rapidly shifted to compensate for lateral eye movement. The high refresh rate permits the apparent compensation of chromatic aberration normally attributed to diffractive lenses when used with polychromatic targets. Color field sequential display rapidly sequentially displays the primary colors in the target while the subject views through corresponding corrected diffractive patterns; color fusion is accomplished in the human visual system. The final power of the pre-compensating element can be mathematically converted into a prescription for eyeglasses, contact lenses or refractive surgery using simple paraxial ray tracing formulas like Equation 1. Returning toFIG.4,FIG.4shows the schematic diagram of the optical path of eye measurement system3000. Eye15is shown at the far left. Light from light sources LS1, LS2, LS3, or LS4may illuminate eye15and create reflected and scattered light that travels toward eye measurement system3000entering through aperture or window W1. L1captures this light and fully or partially collimates it for analysis. Light travels through BS1which may preferentially reflect wavelengths longer than 900 nm and/or may be designed to preferentially reflect S polarized light; BS2may transmit shorter wavelengths. As discussed in greater detail below with respect toFIGS.8-11, optical system4000includes a relay imager comprising lenses L1and L2and a Badal optometer comprising lenses L3and L4as a pre-compensation section which is configurable to bring the target into focus on eye15for making the subjective refraction measurement of the subject's eye15. LIDAR device4100may be fixed to lens L1; L1may move to bring the relay imager into focus. L2is the second lens of the relay imager and this focusses the light from eye15onto a two-dimensional imaging sensor or camera IM1, positioned at Image Plane1. BS2is a partial reflector that allows light from eye15to reach IM1to complete the eye imaging section of optical system4000. The light reflected by BS2travels through a Stokes Cell (“SC”), which allows for continuously adjustable astigmatic correction; SC is positioned at Image Plane1awhich is equidistant from BS2as Image Plane1. Spherical correction is accomplished with the Badal optometer comprised of lenses L3and L4and mirrors M1and M2. Mirrors M1and M3can be translated simultaneously to change the distance between L3and L4, thereby providing continuously adjustable spherical correction. BS3is also a partial reflector for visible light and a high reflector for near infrared (NIR) light. The transmitted visible light allows subject10to view the eye chart; Image Plane2represents the optical position of eye15, with refractive correction applied, when viewing the targets LS5or LS6. The remaining visible and NIR light may be directed toward a wavefront or similar sensor; a point spread function (PSF) sensor is shown inFIG.4. Light is focused by lens L6, positioned at Image Plane2a(equidistant from BS3as Image Plane2) onto imaging sensor IM2; the size and shape of the formed spot can be analyzed to advantageously to drive the Stokes Cell and Badal optometer to correct for eye refractive errors. Imaging sensor IM2measures the radius of curvature of the wavefront of light from eye15using well-known ‘guide-star’ techniques. Imaging sensor IM2may include any of the following: a Shack-Hartmann Sensor, a Phase Diversity Sensor, a Pyramid Sensor, a Curvature Sensor, a point spread function (PSF) Sensor, or a Retro-illumination refractometer. Additional lenses may be included as required to bring the scattered wavefront onto the imaging sensor IM2for proper measurement. Light source LS2may be a NIR super luminescent diode or LED that provides a narrow beam light (e.g., 2 mm diameter) collimated by lens L7and can be used to create a tight spot on the retina of eye15to act as a “guide star.” The output aperture for LS2is positioned at Image Plane2ato ensure that the light is imaged onto the Object Plane. LS3is an alternate light source which may be divergent in contrast to that produced by LS2; it may be used to flood illuminate the retina when imaging the fundus. Like LS2, its output aperture may be approximately 2 mm and is positioned at Image Plane2a. LS2and LS3may be physically translated into position or optically or electronically switched. FIGS.8a,8band8cillustrate an example embodiment of a pre-compensation section8000of an eye measurement system, including a relay imager8100and a Badal optometer8200. This configuration has the advantage of providing a sharp eye image to monitor eye alignment and the current eye state (e.g., open or closed eyelids) while measuring and providing a target with proper refractive correction to the subject. The target is not shown inFIG.8but would be to the right of the position labelled Image Plane2.FIG.8aillustrates the nominal lens positions for a nominal position of eye15relative to the optical system.FIG.8billustrates the lens positions when eye15is positioned further from the optical system than inFIG.8a.FIG.8cillustrates the lens positions when eye15is positioned closer to the optical system than inFIG.8a. Note that the positions of lenses L2and L3do not change. In this embodiment, Relay Imager8100casts a sharp image of eye15at Image Plane1while Badal Optometer8200relays that image onto Image Plane2while also adjusting the wavefront curvature to as to compensate for the refractive error of eye15. Relay Imager8100consists of two lenses, L1and L2of focal length f1and f2, respectively. Relay Imager8100will have its object plane a distance f1from L1and its image plane at a distance f2from L2. This produces an image with fixed magnification −f2/f1at Image Plane1. The motion of eye15is tracked by translating lens L1to maintain a distance of f1to eye15, thus ensuring that a sharp image of eye15will always appear at Image Plane1independent of the position of eye15relative to the optical system. The distance between L1and eye15may be maintained by actuating the position of L1according to an autofocus algorithm or by direct measurement the distance by using a LIDAR device or other distance sensor. Badal Optometer8200similarly consists of two lenses, L3and L4with focal lengths f3and f4. A continuous range of refractive correction may be applied to the wavefront curvature by adjusting the distance between L3and L4. By advantageously placing an astigmatic correction device (e.g., a Stokes cell) at Image Plane1, Badal optometer8200can correct for both spherical and cylindrical refractive errors. Relay Imager8100has the drawback that it may alter the wavefront curvature at Image Planes1and2depending on the separation between L1and L2. However, this correction is deterministic and can be compensated through a small adjustment of the distance between L3and L4as shown inFIGS.9and10. FIG.9illustrates an example embodiment of an operation of a focus loop9000of the pre-compensation section ofFIG.8. Focus loop9000may be implemented by software stored in memory and which is executed by a processor, such as by processing system2200. Operation9100includes reading the position of eye15from LIDAR device4100. Operation9200includes reading the current position of lens L1. Operation9300includes subtracting the positions obtains in operations9100and9200to obtain the eye-to-L1distance. Operation9400includes reading f1(focal length of lens L1) from calibration data. Operation9500includes subtracting f1from the eye-to-L1distance to obtain the tracking error for the position of lens L1. Operation9600includes adding the tracking error to the current position of lens L1to obtain a new target position for lens L1. Operation9700includes moving lens L1to the new target position. Operation9800includes updating the current position of lens L1. Operation9900includes providing the updated current position of lens L1to the refraction correction loop ofFIG.10. FIG.10illustrates an example embodiment of an operation of a refraction correction loop10000of the pre-compensation section ofFIG.8. Refraction correction loop10000may be implemented by software stored in memory and which is executed by a processor, such as by processing system2200. Operation10100includes reading the refraction error from a wavefront sensor. Operation10200includes calculating the refractive correction to the position of lens L4. Operation10300includes obtaining the position of lens L1from the focus loop9000. Operation10400includes reading the position of lens L2from calibration data. Operation10500includes calculating a focus correction to the position of lens L4from the outputs of operations10300and10400. Operation10600includes reading the current position of lens L4. Operation10700includes adding the refraction correction and the focus correction to the current position of lens L4to obtain a new target position for lens L4. Operation10800includes moving the lens L4to the target position. Operation10900includes updating the current position of lens L4. FIG.11illustrates an example embodiment of a pre-compensation section11000of an eye measurement system which is provided with LIDAR device4100. The use of LIDAR device4100simplifies the control algorithm compared to an autofocus algorithm by reducing the calculations required in each control iteration. Compact LIDAR devices4100are commercially available with a range and distance accuracy compatible with such an embodiment. In this case, LIDAR device4100can be mounted to move with L1to directly measure distance from L1to eye15. LIDAR device4100may also be advantageously optically positioned at Image Plane1or2to employ the optical system to ensure that only light reflected from the cornea is used in the ranging.FIG.11illustrates how the light from LIDAR device4100may be collimated with lens L5and sent through L1to focus on the cornea. In this case, lens L5, beam splitter BS1, and the LIDAR unit may move with L1. FIG.12illustrates an external eye examination system12000using light sources to provide illumination of eye15, for example for capturing images of eye15using camera12100. Images of the exterior of eye15are useful for testing pupil function, external examination for pathologies of eye15and surrounding tissues, to test extraocular motility and alignment. Imaging of the anterior of eye15with appropriate lighting from lighting elements12200may permit some level of slit lamp examination. Finally, imaging of the posterior of eye15allows examination of the fundus. In some embodiments, each of these imaging systems could be independently designed and simply mounted at a different location in the eye alignment and tracking system Two or more cameras12100may supply video images of both eyes15to test pupil response, ocular motility, visual confrontation, and for external and internal examination of eyes15and nearby structures (e.g., eyelids). Different visual stimuli may be applied through peripheral or coaxial light sources for each examination element. Light sources12200may be fixed relative to the field of view or may move within it; some light sources may be structured (e.g., images of fingers, or a narrow bright slit); some may be arranged in an array, as described below with respect toFIG.13. In some embodiments, pre-compensation section6100of the optical system may be adjusted to obtain magnified images of the internal or external area of eye15. In some embodiments, pre-compensation section6100may be used to produce an aerial image that is subsequently conditioned to match camera12100. The image can stay in focus despite changes in standoff distance; small magnification differences so introduced can be compensated in the display of the image and in the quantitative analyses as well. The use of additional light sources12200can not only illuminate eye15and surrounding tissue, but also can be used for keratometry and corneal topography if desired. Light sources12200can also provide stimuli to the subject for pupil and confrontation visual field and extraocular motility and alignment testing. In some cases, lighting12200may be controlled to smoothly translate across areas of the peripheral field of view of subject10. In a much similar way, slit lamp examination can be simulated with this same arrangement. FIG.13illustrates an example embodiment of a structured lighting arrangement13000which may be used to illuminate eye15and to create new fixation directions to facilitate ocular measurements. Structured lighting may be used to illuminate eye15and to create new fixation directions to facilitate ocular measurements. Each dot inFIG.13represents an individually addressable light source13200. The ring pattern around aperture13100may be symmetrically disposed around the optic axis of the optical system and may be used to illuminate eye15for eye imaging and/or for keratometric measurement. The array of peripheral light sources13200may be used for corneal topographic measurements and/or to test the integrity of the tear film surface when activated in concert, and/or can act as fixation points to change the gaze of subject10for slit lamp examination, for extraocular motility, and confrontation visual field testing. FIG.14illustrates an example embodiment of a slit lamp illuminator14000of an eye measurement system. The slit lamp illumination is from below eye15and utilizes a Kholer configuration. Light source LS4is imaged onto projector lens L9by condenser lens L8. The slit is created electronically on digital light processing chip, DLP, to form arbitrarily shaped apertures whose dimensions can be controlled electronically with approximately 10 μm resolution and which can be changed at video rates in synchrony with image captures on for example by processing system2200. The slit illuminator assembly also comprises a beam dump, BD1, which may absorb all unwanted light from LS4. This assembly is suspended above or below the LIDAR assembly and moves with the optic assembly3500to maintain alignment with the eye as it moves. The slit lamp illuminator assembly may also rotate about a vertical axis located at eye15, as shown inFIG.15, to allow an operator (e.g., a HCP controlling slit lamp illuminator from an external remote terminal via a communication device of eye examination apparatus1000) to change the angle of incidence continuously over a range of ±60° from the optic axis. Fine positioning of the light image on eye15can be accomplished electronically with the DLP. The observation angle for the scattered light can be adjusted by using a selected LED on LS1to create a fixation target upon which the subject can fixate, thereby rotating eye15and thus the observation angle. FIG.15shows a bottom view of the slit lamp illuminator ofFIG.14. FIG.16illustrates how an example embodiment of an eye measurement system may obtain a fundus image of an eye. Equation 2 below may be applied with respect toFIG.16: 1ffundus=1RoC+CP+1ImageEquation⁢⁢2 In some embodiments, a fundus imager may invoke different gaze angles for subject10using structured lighting13200to attain multiple images with a small field of view which can be stitched together into a high field of view image of the fundus. Fundus imaging also may benefit from the pre-compensation section of the optical system, discussed above. In this case lighting is directed into eye15and knowledge of the refractive state of eye15may simplify maintaining focus. The case shown inFIG.16is essentially direct ophthalmoscopy where the lighting is directed through the nodal point of eye15to illuminate a large section of the fundus. To obtain high angle coverage of the fundus, subject10may be stimulated to gaze in different directions with lighting that creates a moving target while images are captured continuously. Processing system2200may employ image processing to undistort the images and then use fundus landmarks to stitch them into a large field of view fundus image. FIG.17illustrates an example of a fundus image17000of eye15which may be obtained by eye examination apparatus1000and eye measurement system3000as discussed above with respect toFIG.16. In some embodiments, eye examination apparatus1000may include a tonographer (not shown), and in that case the presence and progression of glaucoma may be derived from tonographer measurements. In other embodiments, fundoscopy of eye15allows the eye examination apparatus1000to test for glaucoma of eye15. Examples of a technique for glaucoma detection from a fundus image are disclosed in Shilpa Sameer Kanse, et al., “Retinal Fundus Image for Glaucoma Detection—A Review and Study,” J. INTELL. SYST.2017, the entirety of which is hereby incorporated by reference herein as if fully set forth herein. FIG.18is a flowchart of an example embodiment of a method18000of automated non-contact eye examination. An operation18100includes an eye examination apparatus ascertaining, via an automatic eye tracking arrangement, a current positional relationship of a subject's eye with respect to an optical system of an eye measurement system of the eye examination apparatus. Beneficially, this may be done without human assistance. In some embodiments, operation18100may track the positional relationships for both of a subject's eyes at the same time. An operation18200includes the eye examination apparatus providing light to and from the optical system and a subject's eye(s) while the subject is separated and spaced apart from the housing of the eye examination apparatus and while the eye is not maintained in a fixed positional relationship with respect to the housing. In some embodiments, operation18200may include providing light to and from the optical system to both of a subject's eyes at the same time. In some embodiments, the eye measurement system may have two separate optical systems for the subject's two eyes, and in that case operation18200may include providing light to and from each optical system to a corresponding one of the subject's eyes, for example at the same time. An operation18300includes controlling an optical system movement arrangement of the eye examination apparatus to move the optical system into a predetermined positional relationship with respect to the subject's eye(s). Beneficially, this may be done without human assistance. In some embodiments, the eye examination apparatus may have two separate optical systems for the subject's two eyes, and in that case operation18300may include moving each optical system into a predetermined positional relationship with respect to a corresponding one of the subject's eyes. An operation18400includes the eye examination apparatus making an objective refraction measurement of a subject's eye via the optical system. In various embodiments, operation18400may include making an objective refraction measurement of a subject's eye via a Shack-Hartmann wavefront detector, a phase diversity sensor, a pyramid sensor, a curvature sensor, a point spread function (PSF) sensor, a retro illumination refractometer, etc. In some embodiments, the eye measurement system may have two separate optical systems and object measurement devices for the subject's two eyes, and in that case operation18400may include the eye examination apparatus making an objective refraction measurement of each of the subject's eyes via a corresponding optical system. An operation18500includes the eye examination apparatus interacting with the subject via a user interface, and in response to the interaction adjusting at least one parameter of the optical system to make a subjective refraction measurement of the subject's eye(s) based on the subject viewing a target. Beneficially, the target may be an eye chart. Beneficially, subjective measurements may be made separately for each eye, and a combined subject measurement may be made with the subject viewing the target with both eyes at the same time. An operation18600includes the eye examination apparatus making other measurements and/or examinations of the subject's eye via the optical system, or both eyes in parallel via corresponding optical systems for each eye. In various embodiments, these other measurements and/or examinations may include measuring high order aberrations of the eye, determining intraocular pressure, performing a fundoscopic examination, performing a slit lamp examination, determining keratometry/corneal topography/astigmatism, determining a pupil function, performing confrontation visual field testing (e.g., peripheral vision test), and/or determining extraocular motility. In some embodiments, operation18600may be omitted. An operation18700includes the eye examination apparatus qualifying/filtering eye measurement data. In some embodiments, eye measurement data may be filtered to reject at least a portion of the eye measurement data when the portion of the eye measurement data is taken when the automatic eye tracking arrangement has not aligned the optical system to the eye within a specified level of accuracy. In some embodiments, eye measurement data may be filtered to reject at least a portion of the eye measurement data when the portion of the eye measurement data is taken when the images of the eye fail to meet predefined quality criteria due to at least one of: a full blink, a partial blink, an incorrect gaze angle, incomplete dis-accommodation, and a saccade. In some embodiments, operation18700may be omitted. An operation18800includes communicating eye measurement data from the eye examination apparatus to an external remote terminal for evaluation, for example by a healthcare professional. The remote terminal may be a computer, a laptop, a tablet device, or even a cell phone. In some embodiments, the external remote terminal may be disposed in a different room than the eye examination apparatus. In some embodiments, the external remote terminal may be disposed in another building, another city, another state/province, or even another country than the eye examination apparatus. In some embodiments, the eye measurement data may be communicated via the Internet. In some embodiments, the eye measurement data may be communicated in real time, as it is processed by the eye examination apparatus. In some embodiments, the eye examination apparatus only communicates filtered eye measurement data which was filtered in operation18700. An operation18900includes the eye examination apparatus providing information messages via display device2400provided at an external surface of the housing to the subject and/or an observer who is within sight of the display device. In some embodiments, such information messages may include advertisements or commercials, which may be in the form of images or video. In some embodiments, advertisements may be displayed on display device2440on an external face of housing1100when eye examination apparatus1000is not in use. These advertisements can provide information about eye examination apparatus1000, can provide information about vision health insurance or other public services, or can simply be promotional material from paid sponsors. Furthermore, advertisements can be played on the internal display (seeFIG.22) that is used for the subject visual target at any time during the examination. An example would be right after an objective refraction has been completed so that the refraction results can be used to ensure that the instrument will display the informational content in a clear fashion. In various embodiments, method18000may include additional operations to those shown inFIG.18. In some embodiments, the eye measurement apparatus may display a QR code (or bar code) with instructions on the video monitor instructing subject10to use their camera to sign up for an eye exam. The QR code or hyperlink that connects the potential subject with the instrument (or a network) in order to sign up for and potentially initiate the eye examination. In some embodiments, when before, during, and/or after a subject encounter with an eye examination apparatus, the subject supplies personal information, including identification information, and may complete a patient intake survey. In some embodiments, this may be accomplished by providing the eye examination apparatus with a webserver which may interact with the subject's mobile phone, tablet or laptop. In some embodiments, a web service accessible via the internet which handles eye examination scheduling may provide these functions, rather than supplying each eye examination apparatus with a webserver. FIG.19illustrates an example of a web page which may be displayed on a subject's cell phone before, during and/or after an interaction with the eye examination apparatus. FIG.20illustrates an example embodiment for a workflow20000for an eye examination of an eye. FIG.20illustrates operations (20010and20020) which occur when the eye examination apparatus is located in an eyecare clinic, operations which occur when the eye examination apparatus is an unattended kiosk (20110,20120and20130), and operations which are common to both situations (all remaining operations). An operation20010includes an eye examination subject, or patient, checking in at the front office of an eye care clinic at the time of appointment. An operation20020includes leading the subject to the eye examination apparatus, and a health care professional (HCP) technician provides audio cues to look at a target in the eye examination apparatus. An operation20110includes an eye examination subject, or patient, walking up to a kiosk comprising an eye examination apparatus and checking in to the kiosk using a smartphone app, and initiating an eye examination. An operation20120includes a HCP logging onto a web portal via an external remote terminal. An operation20210includes the subject standing in front of instrument and receiving audio clues to look for the fixation target. An operation20215includes the eye examination apparatus detecting the presence of the subject, starting gross alignment with the subject's eye(s), and providing audio instructions to the subject. An operation20220includes auto-aligning an optical system to the correct height for the subject, performing fine alignment for interpupillary distance, estimating a working distance to the eye(s), and begin tracking the eye(s). An operation20225includes performing an initial objective measurement of refraction, pre-compensating the target path by correcting for the initially-measured refraction, making multiple refraction measurements of the eye(s), capturing images of the anterior pupil of each eye, and tracking eye motion and head motion while compensating the target path. An operation20230includes providing audio clues for the subject and moving the target. An operation20235includes the subject receiving instructions to watch a moving fixation target, and the subject watching the moving fixation target. An operation20240includes an unseen infrared (IR) illumination illuminating the fundus of the subject's eye(s) under a controlled sequence of gaze angles. Several images of different portions of the fundus may be processed and stitched together to build a larger image of the fundus. An operation20245includes the eye examination apparatus either being controlled by the HCP for a subjective refraction test (e.g., via a tablet device), or running an automated algorithm (kiosk implementation), with the subject responding to standard yes/no questions using voice recognition. Monocular subjective refraction for each eye may be determined. An operation20250includes a subject answering subjective questions about visual acuity for each eye, for example: “Which one is better? 1 or 2?” An operation20255includes the eye examination apparatus assembling eye measurement data or results and providing the assembled eye measurement data/results to the HCP, either via a clinic internal network or HIPAA web portal, and informing a subject and a remote HCP that the eye examination has completed. An operation20130includes the HCP receiving patient data and the assembled eye measurement data/results. An operation20260includes the HCP reviewing the assembled eye measurement data/results (e.g., subjective vs objective refraction, fundus imaging, etc.) and deciding whether the subject needs a manual refraction or retinal examination. An operation20265includes the HCP discussing the eye examination results in person or over a web portal, and providing the subject with a prescription. An operation20270includes the HCP updating internal patient records with information from the eye examination, and potentially scheduling a follow-up eye examination. FIG.21illustrates an example embodiment for a workflow21000for an eye examination apparatus to make a subjective (manifest) refraction measurement of an eye. InFIG.21, the following applies: ss=increment step size; max=max tries; maxOM=OverMinus tries; OR=Objective Refraction; CR=current refraction; FR=final refraction; Thresh=convergence threshold; OM thresh=over-minus threshold. In an example: beginning ss=1.0 D, cnt=0, cnt2=0 and beginning CR=OR. Workflow21000uses voice recognition and captures subject facial responses during a subjective refraction for post-measurement review by a Health Care Provider (HCP). The starting point for the subjective examination is after the eye examination apparatus has captured an objective refraction for the eye(s). The objective refraction may be used as the starting point for the subjective refraction measurement. The sphero-cylindrical compensation may be added to the target path (e.g., also accounting for chromatic aberrations and for lane length). Each choice may be briefly presented to the subject, e.g., for 3-5 seconds. An example in English follow (in some embodiments, other languages may be available). In this example, the eye examination apparatus gives verbal instructions to the subject (e.g., through a speaker) as follows: Apparatus: “We will begin a subjective test now—please listen and respond to questions.” Apparatus: “Yes or no—Is the target clear to you now?” If the subject answers no, the eye examination apparatus may reperform the objective refraction measurement or select the most hyperopic objective measurement result. If the subject answers yes, the algorithm proceeds to the next step, and moves on after two additional tries. Apparatus: “You will now be presented with a choice of targets—please tell the instrument which option is better by answering with one, two, same, neither or repeat. Answer neither if neither choice of targets is clear. Answer same if both choices of targets are clear, and it is difficult to determine which is better. Answer repeat if you would like to see both choices again.” FIG.22illustrates an example embodiment of an eye target22000which may be used to communicate with a subject. To further prevent the need for touch screen responses and to assist hearing impaired subjects, messages and possible subject responses can be displayed as words in the subject's preferred language or sign language, or as icons on the target screen. The eye examination apparatus may use voice recognition to determine the subject's response, or the eye examination apparatus may determine the subject's response based upon which of the provided response areas on the display the subject is fixating their eye(s) upon, and/or may interpret sign language or facial expressions to determine subject responses. As disclosed above, an eye examination apparatus comprising a multi-function ophthalmic instrument for eye health and vision examinations does not require the subject's head to be constrained during examination. It automatically and continuously aligns an internal eye measurement system to the subject's eye(s) during the measurements, regardless of normal subject motion. The optical paths for all measurements include a sufficiently large standoff to allow all measurements to take place with the subject standing comfortably distant from the housing of the instrument, including for example a protective window separating the subject from the measurement module. The eye measurement system is capable of video rate measurements. Audio/visual cues may be provided remotely by the instrument, technician, or physician prior to, during, and after the measurement(s). By incorporating a housing with an easily disinfected smooth outer shell, and by eliminating the traditional headrest and chair, the apparatus can measure subject's eyes without the need for the subject to contact any instrument surfaces or to be in proximity to a technician or HCP during the measurements, thus greatly reducing the risks of cross contamination. While example embodiments are disclosed herein, one of ordinary skill in the art appreciates that many variations that are in accordance with the present teachings are possible and remain within the scope of the appended claims. The invention therefore is not to be restricted except within the scope of the appended claims.

11857260

The drawings depict various embodiments for the purpose of illustration only. Those skilled in the art will recognize that alternative embodiments may be employed without departing from the principles of the technology. Accordingly, while specific embodiments are shown in the drawings, the technology is amenable to various modifications. DETAILED DESCRIPTION Retinal cameras are designed to provide an upright, magnified view of the fundus. Typically, a retinal camera views 30-50° of the retinal area with a magnification of 2.5×, though these values may be modified using zoom lenses, auxiliary lenses, wide angle lenses, etc. FIG.1depicts an example of a retinal camera. Generally, a subject will sit at the retinal camera with their chin set within a chin rest and their forehead pressed against a bar. An ophthalmic photographer can then visually align the retinal camera (e.g., using a telescopic eyepiece) and press a shutter release that causes an image of the retina to be captured. More specifically,FIG.1illustrates how light can be focused via a series of lenses through a masked aperture to form an annulus that passes through an objective lens and onto the retina. The illuminating light rays are generated by one or more light sources (e.g., light-emitting diodes), each of which is electrically coupled to a power source. When the retina and the objective lens are aligned, light reflected by the retina passes through the un-illuminated hole in the annulus formed by the masked aperture of the retinal camera. Those skilled in the art will recognize that the optics of the retinal camera are similar to those of an indirect ophthalmoscope in that the illuminating light rays entering the eye and the imaging light rays exiting the eye follow dissimilar paths. The imaging light rays exiting the eye can initially be guided toward a telescopic eyepiece that is used by the ophthalmic photographer to assist in aligning, focusing, etc., the illuminating light rays. When the ophthalmic photographer presses the shutter release, a first mirror can interrupt the path of the illuminating light rays and a second mirror can fall in front of the telescopic eyepiece, which causes the imaging light rays to be redirected onto a capturing medium. Examples of capturing mediums include film, digital charge-coupled devices (CCDs), and complementary metal-oxide-semiconductors (CMOSs). In some embodiments, retinal images are captured using colored filters or specialized dyes (e.g., fluorescein or indocyanine green). Accordingly, stable alignment of the eye and the retinal camera is critical in capturing high-resolution retinal images. But maintaining such an alignment can be challenging due to the required precision and lack of direct eye gaze control. Introduced here, therefore, are retinal cameras having optical stops whose size and/or position can be modified to increase the size of the space in which an eye can move while being imaged (also referred to as the “eyebox”). The term “optical stop” refers to the location where light rays entering a retinal camera are traced. Because a retinal camera images light rays reflected back into the retinal camera by the retina, the optical stop is arranged along a plane located inside the retinal camera. This stands in contrast to other types of eyepieces (e.g., head-mounted devices) where the eye (and, more specifically, the iris) represents the optical stop. For these eyepieces, altering the position of the optical stop does not cause displacement of the light rays along a detector.FIG.2depicts how moving the eye vertically along the pupil plane may only change the angle of incidence (AOI) of the light rays to the detector. Here, the first optical stop position represents the optimal eye location (i.e., where the image of the highest quality would be captured) and the second optical stop position represents another position within the eyebox. Because the eye itself acts as the optical stop, a subject can move their eye between the first and second positions without causing vertical or horizontal displacement of the light rays along the detector. There are several key differences between optical systems having large optical stops and optical systems having smaller optical stops that move to the pupil position. For example, a large optical stop will ensure that an optical system has a small f-number, which is the ratio of the optical system's focal length to the diameter of the entrance pupil. But this can make the optical system more difficult (and more expensive) to construct. A smaller optical stop will limit the amount of light allowed within the imaging space. If the optical stop is smaller than the pupil, then light is lost that would reduce the brightness of the resulting image. Accordingly, it is desirable to make the optical stop substantially the same size as the pupil (e.g., after accounting for magnification). To address movement of the pupil, the retinal cameras introduced here can adjust the position of the optical stop while still maintaining roughly the same diameter as the pupil. Embodiments may be described with reference to particular imaging configurations, eyepieces, etc. However, those skilled in the art will recognize that the features described herein are equally applicable to other imaging configurations, eyepieces, etc. Moreover, the technology can be embodied using special-purpose hardware (e.g., circuitry), programmable circuitry appropriately programmed with software and/or firmware, or a combination of special purpose hardware and programmable circuitry. Accordingly, embodiments may include a machine-readable medium having instructions that may be used to program a computing device to perform a process for tracking the position of an eye, modifying the position of an optical stop, processing image data to generate a retinal photograph, etc. Terminology References in this description to “an embodiment” or “one embodiment” means that the particular feature, function, structure, or characteristic being described is included in at least one embodiment. Occurrences of such phrases do not necessarily refer to the same embodiment, nor are they necessarily referring to alternative embodiments that are mutually exclusive of one another. Unless the context clearly requires otherwise, the words “comprise” and “comprising” are to be construed in an inclusive sense rather than an exclusive or exhaustive sense (i.e., in the sense of “including but not limited to”). The terms “connected,” “coupled,” or any variant thereof is intended to include any connection or coupling, either direct or indirect, between two or more elements. The coupling/connection can be physical, logical, or a combination thereof. For example, components may be electrically or communicatively coupled to one another despite not sharing a physical connection. The term “based on” is also to be construed in an inclusive sense rather than an exclusive or exhaustive sense. Thus, unless otherwise noted, the term “based on” is intended to mean “based at least in part on.” When used in reference to a list of multiple items, the word “or” is intended to cover all of the following interpretations: any of the items in the list, all of the items in the list, and any combination of items in the list. The sequences of steps performed in any of the processes described here are exemplary. However, unless contrary to physical possibility, the steps may be performed in various sequences and combinations. For example, steps could be added to, or removed from, the processes described here. Similarly, steps could be replaced or reordered. Thus, descriptions of any processes are intended to be open-ended. Technology Overview Alignment is one of the most difficult tasks of retinal imaging. Conventional retinal cameras, for instance, typically require a trained operator, proper securement of the head position, and non-trivial mechanical controls to ensure precise alignment of the eye and imaging components within the retinal camera (e.g., the lenses, optical stop, and detector). Consequently, the eyebox dimensions of conventional retinal cameras are often extremely limited. This makes proper alignment of the eye and the retinal camera difficult, particularly if the subject begins to shift their eye during the imaging process. Several solutions have been proposed to address the problems posed by small eyeboxes. However, these proposed solutions add mechanical complexity to the retinal camera (and thus increase the cost). Introduced here, therefore, are several different technologies for recovering the eyebox during the imaging process, including:A mechanical optical stop that can be moved horizontally and/or vertically to recover retinal image quality as the subject shifts their eye.A digital optical stop that can be created using a pixelated liquid crystal display (LCD) layer including multiple pixels that are individually controllable.Multiple non-pixelated LCD layers that can be connected to one another to form a stack. Each LCD layer within the stack may be offset from the other LCD layers. Accordingly, the optical stop of the retinal camera can be moved by changing which LCD layer is active at a given point in time. Each of these technologies is further described below. FIG.3illustrates a generalized side view of a retinal camera300. Here, the retinal camera300includes an optical stop302interposed between a series of lenses304and a detector306(also referred to as a “capturing medium”). Generally, the detector306is arranged directly adjacent to the series of lenses304. Other embodiments of the retinal camera300may include some or all of these components, as well as other components not shown here. For example, the retinal camera may include one or more light sources, mirrors for guiding light emitted by the light source(s), a power component (e.g., a battery or a mechanical power interface, such as an electrical plug), a display screen for reviewing retinal images, etc. As noted above, in some embodiments the optical stop302is moved to recover additional light reflected by the eye308as the eye308moves. Here, for example, the eye308has shifted down two millimeters (mm) from the optimal optical axis and the optical stop302has shifted down one mm. Such movement allows more of the imaging light rays returning from the eye308(e.g., the imaging light rays ofFIG.1) to be guided through the series of lenses304and captured by the detector306. The relationship between eye shift and optical stop shift may be substantially linear (e.g., approximately two-to-one). Such a relationship allows the proper position of the optical stop302to be readily established so long as the position of the eye308can be accurately established. In some embodiments, the optical stop302is moved manually. For example, the retinal photographer may visually observe the imaging light rays (e.g., via a telescopic eyepiece) during an imaging session and alter the position of the optical stop302using indexing wheel(s), joystick(s), etc. In other embodiments, the optical stop302is moved automatically without requiring input from the retinal photographer or the subject. For example, the retinal camera300may instruct servomotor(s) to alter the position of the optical stop302responsive to adjustments specified by software executing on the retinal camera300or another computing device communicatively coupled to the retinal camera300. Separate servomotors may be used to alter the position of the optical stop302along the x-axis (i.e., horizontally) and the y-axis (i.e., vertically). Other mechanisms may also be used to achieve linear motion of the optical stop302, including cam(s), stepper motor(s), pneumatic cylinder(s)/actuator(s), piezoelectric actuator(s), voice coil(s), etc. In some embodiments, movement may occur along a single axis. That is, the optical stop could be restricted to one-dimensional movement (e.g., along the x-axis or the y-axis). For example, movement of the optical stop may be restricted to a curved dimension (e.g., a circular/ellipsoidal path, a rectangular path, or a spiral path). The software may apply image processing algorithms to identify certain features (e.g., vignetting) that are indicative of increases/decreases in retinal image quality. For example, the software may perform image segmentation (e.g., thresholding methods such as Otsu's method, or color-based segmentation such as K-means clustering) on individual retinal images to isolate features of interest. After the software has identified the retinal image having the highest quality, the software can output instructions that cause the servomotor(s) to modify the position of the optical stop302. Image quality can depend on one or more factors, such as brightness level, whether vignetting is present, modulation transfer function (MTF) quality, act. Thus, a subject may be able to look into the retinal camera300without being concerned about alignment of the eye308and the optical stop302. Instead, the retinal camera300could automatically determine the location of the eye308and move the optical stop302accordingly. More specifically, the retinal camera300may include a mechanism (e.g., a servomotor) operable to reposition the optical stop and a controller configured to adaptively reposition the optical stop responsive to a determination that the eye308has moved during the imaging process. For example, the controller may determine the amount of movement caused by a spatial adjustment of the eye, and then cause the mechanism to reposition the optical stop accordingly. As noted above, the amount of movement caused by the spatial adjustment of the eye may be related (e.g., proportional to) the amount by which the optical stop is repositioned. Thus, the optical stop302could be moved to ensure alignment with the eye308, rather than moving the entire retinal camera300or the eye308itself. In some embodiments, optimized adjustments also occur based on, for example, an image quality feedback loop or some other feedback loop. Several different mechanisms can be used to detect the location of the eye308. For example, infrared light source(s) may be arranged to project infrared beam(s) into the visible light illumination path of the retinal camera300. Because the iris generally does not constrict when illuminated by infrared light, a live view of the retina can be captured and used to establish the position of the eye308. As another example, the iris may be detected using a software-implemented search pattern. More specifically, the retinal camera300could capture a series of retinal images with the optical stop302located at different positions. The ideal position for the optical stop302may be determined based on whether the retina is detected within any of the retinal images. Other mechanisms for detecting eye location include conventional eye tracking techniques, pupil discover via machine vision, Light Detection and Ranging (LIDAR), radio frequency (RF) object sensing at certain frequencies (e.g., 60 GHz), simple reflection off the cornea, etc. The optical transfer function (OTF) of an optical system (e.g., a retinal camera) specifies how different spatial frequencies are handled by the optical system. A variant, the modulation transfer function (MTF), neglects phase effects but is otherwise equivalent to the OTF in many instances. FIG.4Adepicts the MTF of the retinal camera300before the optical stop302has been shifted, whileFIG.4Bdepicts the MTF of the retinal camera300after the optical stop302has been shifted. Here, the x-axis represents spatial frequency and the y-axis represents modulation. Each line shown in the MTF represents a different field angle. Lines corresponding to the lowest field angles (i.e., those that are closest to the optimal optical axis) will typically have the highest modulation values, while lines corresponding to the highest field angles (i.e., those that are furthest from the optimal optical axis) will typically have the lowest modulation values. Shifting the optical stop302improves retinal image quality by recovering additional light reflected into the retinal camera300by the eye308. Here, for example, the lines corresponding to the high field angles furthest off the optimal optical axis are recovered the most. This is evident in both the increased modulation values and greater definition shown inFIG.4B. FIG.5Adepicts a retinal camera500attempting to image the retina of an eye508that has shifted downward by 1.5 mm. The retinal camera500can include an optical stop502interposed between a series of lenses504and a detector506. As noted above, light rays reflected back into the retinal camera500by the retina will be guided through the series of lenses504toward the optical stop502and the detector506. However, if the eye508shifts horizontally or vertically with respect to the optical axis and the optical stop502remains in its original location, the light rays will be displaced along the detector506. Said another way, the light rays will be guided through the series of lenses504in such a manner that the light rays no longer fall upon the detector506in the same location as if the eye508were imaged in its original position. Small shifts in the position of the eye508can create noticeable changes in image quality.FIG.5B, for example, shows how the downward shift of 1.5 mm has caused vignetting to occur in the image formed by the detector506. Vignetting generally refers to the reduction of brightness or saturation at the periphery compared to the center of the image. Here, for instance, vignetting is apparent in the changes to the colors and contrast along the periphery of the image (e.g., in comparison to the image ofFIG.6B). FIG.6Adepicts the retinal camera500after the optical stop502has been shifted downward to compensate for the downward shift of the eye508. As noted above, movement of the optical stop502may be proportional to movement of the eye508. In fact, the relationship between eye shift and optical stop shift may be substantially linear (e.g., approximately two-to-one). Accordingly, the optical stop502may be shifted downward by approximately 0.75 mm to compensate for the downward shift of the eye508by 1.5 mm. Such movement by the optical stop502enables the retinal camera500to recover retinal image quality as the eye508shifts. When the eye508is imaged along the optimal optical axis, light rays reflected back into the retinal camera500by the eye508will fall upon the detector508in one or more specified locations. Moving the optical stop502based on the eye shift causes the light rays to fall upon the detector506nearer the specified location(s) than would otherwise occur.FIG.6Bshows how a corresponding shift in the optical stop502can recover some of the light rays entering the retinal camera500, and thus improve retinal image quality. FIG.7depicts a pixelated liquid crystal display (LCD) layer700having multiple pixels that are individually controllable. The LCD layer700may be electrically coupled to a power component702that is able to separately apply a voltage to each pixel to vary its transparency. Provisioning voltage in such a manner allows the power component702to digitally create an optical stop by changing which pixel(s) in the LCD layer700are active at a given point in time. Such action can be facilitated by one or more polarizing layers (also referred to as “polarizers”) arranged within, or adjacent to, the LCD layer700. Changing the transparency of a pixel will allow light to pass through the corresponding segment of the LCD layer700. For example, a segment of the LCD layer700that includes one or more pixels may appear substantially transparent when used as an optical stop. The remainder of the LCD layer700may appear partially or entirely opaque. To move the optical stop, the power component702may apply voltage(s) causing substantially transparent pixels to become substantially opaque and/or causing substantially opaque pixels to become substantially transparent. Here, the LCD layer700is illustrated as a circle. However, those skilled in the art will recognize that the outer bounds of the LCD layer700could form another geometric shape. For example, other shapes (e.g., a square, rectangle, or ellipsoid) may be preferred based on the configuration of the retinal camera, the expected movement of the eye, the design of the digitally-created optical stop, etc. Moreover, the LCD layer700could include any number of pixels. In some embodiments, the LCD layer700includes tens or hundreds of pixels. In such embodiments, the optical stop may be defined by multiple pixels (e.g., a four-by-four pixel segment). In other embodiments, the LCD layer700includes fewer pixels, though those pixels are often larger in size. For example, the LCD layer700may include four, six, or eight separately-controlled pixels. In such embodiments, the optical stop may be defined by a single pixel. Note that other forms of pixelated display technologies may also be used, such as plasma display panels (PDPs). Thus, the LCD layer700could instead be a “variable transparency layer” able to alter its appearance in several different ways. For example, the variable transparency layer may vary its opacity when a voltage is applied via polymer dispersed liquid crystal (PDLC) technology. Voltage can be used to change the position and orientation of liquid crystals disposed within a polymer matrix in order to allow more or less light to pass through the variable transparency layer. In such embodiments, the variable transparency layer can include electrically-conductive coatings (e.g., polyethylene terephthalate (PET)) on each side of a polymer matrix that includes randomly-arranged liquid crystals. When the power component702applies a voltage to the conductive coatings, the liquid crystals within the polymer matrix become aligned and the variable transparency layer becomes substantially or entirely transparent. However, when the power component702ceases to apply the voltage, the liquid crystals scatter and the variable transparency layer becomes substantially opaque or translucent. As another example, the variable transparency layer may darken its appearance when a voltage is applied via electrochromism. Electrochromism enables some materials to reversible change opacity by using bursts of voltage to cause electrochemical redox reactions in electrochromic materials. In such embodiments, the variable transparency layer may include a first conducting oxide layer, an electrochromic layer (e.g., tungsten oxide (WO3)), an ion conductor layer, an ion storage layer (e.g., lithium cobalt oxide (LiCoO2)), and a second conducting oxide layer. The conducting oxide layers may be thin films of optically-transparent, electrically-conductive materials, such as indium tin oxide (ITO). The conducting oxide layers could also be composed of other transparent conductive oxides (TCOs), conductive polymers, metal grids, carbon nanotubes, graphene, ultrathin metal films, or some combination thereof. The ion conductor layer can include a liquid electrolyte or a solid (e.g., inorganic or organic) electrolyte. In such embodiments, the power component702(which is coupled to the conducting oxide layers) is able to selectively apply a voltage to either of the conducting oxide layers, which drives ions from the ion storage layer into the electrochromic layer and vice versa. An ion-soaked electrochromatic layer is able to reflect light, thereby enabling the variable transparency layer to appear at least partially opaque. Electrochromic and PDLC techniques have been selected for the purpose of illustration. Other technologies that enable the modification of light transmission properties could also be used to achieve the same (or similar) effects, such as photochromic, thermochromic, suspended particle, and micro-blind techniques. FIG.8depicts a variable transparency stack804having multiple LCD layers800that are individually controllable. As shown inFIG.7, a single transparent LCD layer may have a periodic pattern that causes it to be pixelated. For example, a substrate (e.g., ITO) may be patterned with a grid of pixels that are separately controllable. However, unlike the pixelated LCD layer700ofFIG.7, each LCD layer of the multiple LCD layers800included in the variable transparency stack804is typically non-pixelated. Here, for example, a substrate (e.g., ITO) is patterned with a geometric shape (e.g., a circle) to form each LCD layer. But rather than pixelate the LCD layers800, each LCD layer is instead separately connected to the power component802(e.g., using separate leads). This ensures that each LED layer can be controlled independently of the other LED layer(s). The multiple LCD layers800can be connected to one another to form the variable transparency stack804. As shown inFIG.8, each LCD layer within the variable transparency stack804may be offset from the other LCD layers. In some embodiments, each of the LCD layers800partially overlaps at least one other LCD layer. The optical stop of the retinal camera can be moved by changing which LCD layer is active at a given point in time. Thus, the LCD layers800within the variable transparency stack804may be lit or unlit depending on the position of the eye being imaged. The variable transparency stack804may include any number of LED layers800. For example, embodiments may include four, six, eight, or ten LED layers. Moreover, the LED layers800within the variable transparency stack804may be of the same size and/or shape, or different sizes and/or shapes. The outer bounds of the variable transparency stack804limit the possible positions of the optical stop. The arrangement of the LCD layers800(and thus the outer bounds of the variable transparency stack804) may be based on factors influencing the optical design of the retinal camera as a whole, including the number, type, or placement of lenses (e.g., the lenses304ofFIG.3), the expected eye location, etc. The variable transparency stack804can include the multiple LCD layers800and other layers (e.g., optically-clear adhesive layers). For example, optically-clear bonding layers may be used to bind the LCD layers800to one another. Each bonding layer can include an adhesive (e.g., an acrylic-based adhesive or a silicon-based adhesive). Moreover, each bonding layer is preferably substantially or entirely transparent (e.g., greater than 99% light transmission). The bonding layers may also display good adhesion to a variety of substrates, including glass, ITO, polyethylene (PET), polycarbonate (PC), polymethyl methacrylate (PMMA), etc. An optical stop unit including the optical stop302ofFIG.3, the variable transparency stack804ofFIG.8, or the LCD layer700ofFIG.7can be adapted for use within an ophthalmic imaging apparatus. For example, in some embodiments the optical stop unit includes a unit housing designed to fit within the ophthalmic imaging apparatus. Other components (e.g., the power component702ofFIG.7or the power component802ofFIG.8) could also reside within the unit housing. Moreover, the optical stop unit may include a communication interface configured to receive a command from a controller of the ophthalmic imaging apparatus, and then select a voltage to apply based on the command. The voltage could cause servomotor(s) to move the optical stop302ofFIG.3, certain pixel(s) within the LCD layer700ofFIG.7to become transparent, or certain layer(s) within the variable transparency stack804ofFIG.8to become transparent. FIG.9depicts a flow diagram of a process900for recovering retinal image quality as a subject shifts their eye during the imaging process. Initially, the subject places an eye proximate to the objective lens of a retinal camera (step901). The subject will typically sit near the retinal camera with their chin set within a chin rest and their forehead pressed against a bar. The retinal camera can then determine the location of the eye being imaged by the retinal camera (step902). As noted above, several different mechanisms may be used to establish the location of the eye (and, more specifically, the iris). For example, infrared light source(s) may be configured to project infrared beam(s) into the visible light illumination path of the retinal camera. Because the iris will generally not constrict when illuminated by infrared light, a live view of the retina can be captured and used to establish the position of the eye. As another example, the retinal camera may capture retinal images with the retinal stop located at different positions. Image processing algorithm(s) may be applied to the retinal images to determine whether the retina has been captured in any of the retinal images. After determining the location of the eye, the retinal camera can set the position of the optical stop (step903). The position of the optical stop can be set manually or automatically. For example, a retinal photographer may visually observe the imaging light rays produced by the retinal camera (e.g., via a telescopic eyepiece) and alter the position of the optical stop using indexing wheel(s), joystick(s), etc. As another example, the retinal camera may instruct servomotor(s) to alter the position of the optical stop responsive to adjustments specified by software executing on the retinal camera or another computing device communicatively coupled to the retinal camera. The retinal camera can then generate a retinal image from light rays reflected into the retinal camera by the eye (step904). Such action may be prompted by the retinal photographer pressing a shutter release that causes the retinal image to be captured. In some embodiments, the retinal camera continually or periodically monitors the position of the eye (step905). The retinal camera may use the same tracking mechanism used to initially determine the location of the eye or a different tracking mechanism. For example, the retinal camera may use a higher-resolution tracking mechanism to continually monitor the position of the eye so that small variations (e.g., those less than one mm) can be consistently detected. Responsive to determining that the position of the eye has changed, the retinal camera can modify the position of the optical stop (step906). The optical stop may be automatically moved without requiring input from the retinal photographer or the subject. For example, the retinal camera may once again instruct the servomotor(s) to alter the position of the optical stop responsive to adjustments specified by the software executing on the retinal camera or another computing device communicatively coupled to the retinal camera. Thus, the subject may be able to look into the retinal camera without being concerned about alignment of the eye and the optical stop. Instead, the retinal camera could automatically determine the location of the eye and move the optical stop accordingly. Unless contrary to physical possibility, it is envisioned that the steps described above may be performed in various sequences and combinations. For example, the retinal camera may automatically generate a retinal image from light rays reflected into the retinal camera by the eye each time the position of the optical stop is modified. Other steps may also be included in some embodiments. Processing System FIG.10is a block diagram illustrating an example of a processing system1000in which at least some operations described herein can be implemented. For example, some components of the processing system1000may be hosted on a retinal camera (e.g., retinal camera300ofFIG.3), while other components of the processing system1000may be hosted on a computing device that is communicatively coupled to the retinal camera. The computing device may be connected to the retinal camera via a wired channel or a wireless channel. The processing system1000may include one or more central processing units (“processors”)1002, main memory1006, non-volatile memory1010, network adapter1012(e.g., network interface), video display1018, input/output devices1020, control device1022(e.g., keyboard and pointing devices), drive unit1024including a storage medium1026, and signal generation device1030that are communicatively connected to a bus1016. The bus1016is illustrated as an abstraction that represents one or more physical buses and/or point-to-point connections that are connected by appropriate bridges, adapters, or controllers. The bus1016, therefore, can include a system bus, a Peripheral Component Interconnect (PCI) bus or PCI-Express bus, a HyperTransport or industry standard architecture (ISA) bus, a small computer system interface (SCSI) bus, a universal serial bus (USB), IIC (I2C) bus, or an Institute of Electrical and Electronics Engineers (IEEE) standard 1394 bus (also referred to as “Firewire”). The processing system1000may share a similar computer processor architecture as that of a desktop computer, tablet computer, personal digital assistant (PDA), mobile phone, game console (e.g., Sony PlayStation® or Microsoft Xbox®), music player (e.g., Apple iPod Touch®), wearable electronic device (e.g., a watch or fitness band), network-connected (“smart”) device (e.g., a television or home assistant device), virtual/augmented reality systems (e.g., a head-mounted display such as Oculus Rift® or Microsoft Hololens®), or another electronic device capable of executing a set of instructions (sequential or otherwise) that specify action(s) to be taken by the processing system1000. While the main memory1006, non-volatile memory1010, and storage medium1026(also called a “machine-readable medium”) are shown to be a single medium, the term “machine-readable medium” and “storage medium” should be taken to include a single medium or multiple media (e.g., a centralized/distributed database and/or associated caches and servers) that store one or more sets of instructions1028. The term “machine-readable medium” and “storage medium” shall also be taken to include any medium that is capable of storing, encoding, or carrying a set of instructions for execution by the processing system1000. In general, the routines executed to implement the embodiments of the disclosure may be implemented as part of an operating system or a specific application, component, program, object, module, or sequence of instructions (collectively referred to as “computer programs”). The computer programs typically comprise one or more instructions (e.g., instructions1004,1008,1028) set at various times in various memory and storage devices in a computing device. When read and executed by the one or more processors1002, the instruction(s) cause the processing system1000to perform operations to execute elements involving the various aspects of the disclosure. Moreover, while embodiments have been described in the context of fully functioning computing devices, those skilled in the art will appreciate that the various embodiments are capable of being distributed as a program product in a variety of forms. The disclosure applies regardless of the particular type of machine or computer-readable media used to actually effect the distribution. Further examples of machine-readable storage media, machine-readable media, or computer-readable media include recordable-type media such as volatile and non-volatile memory devices1010, floppy and other removable disks, hard disk drives, optical disks (e.g., Compact Disk Read-Only Memory (CD-ROMS), Digital Versatile Disks (DVDs)), and transmission-type media such as digital and analog communication links. The network adapter1012enables the processing system1000to mediate data in a network1014with an entity that is external to the processing system1000through any communication protocol supported by the processing system1000and the external entity. The network adapter1012can include one or more of a network adaptor card, a wireless network interface card, a router, an access point, a wireless router, a switch, a multilayer switch, a protocol converter, a gateway, a bridge, bridge router, a hub, a digital media receiver, and/or a repeater. The network adapter1012may include a firewall that governs and/or manages permission to access/proxy data in a computer network, and tracks varying levels of trust between different machines and/or applications. The firewall can be any number of modules having any combination of hardware and/or software components able to enforce a predetermined set of access rights between a particular set of machines and applications, machines and machines, and/or applications and applications (e.g., to regulate the flow of traffic and resource sharing between these entities). The firewall may additionally manage and/or have access to an access control list that details permissions including the access and operation rights of an object by an individual, a machine, and/or an application, and the circumstances under which the permission rights stand. The techniques introduced here can be implemented by programmable circuitry (e.g., one or more microprocessors), software and/or firmware, special-purpose hardwired (i.e., non-programmable) circuitry, or a combination of such forms. Special-purpose circuitry can be in the form of one or more application-specific integrated circuits (ASICs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), etc. Remarks The foregoing description of various embodiments of the claimed subject matter has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the claimed subject matter to the precise forms disclosed. Many modifications and variations will be apparent to one skilled in the art. Embodiments were chosen and described in order to best describe the principles of the invention and its practical applications, thereby enabling those skilled in the relevant art to understand the claimed subject matter, the various embodiments, and the various modifications that are suited to the particular uses contemplated. Although the Detailed Description describes certain embodiments and the best mode contemplated, the technology can be practiced in many ways no matter how detailed the Detailed Description appears. Embodiments may vary considerably in their implementation details, while still being encompassed by the specification. Particular terminology used when describing certain features or aspects of various embodiments should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the technology with which that terminology is associated. In general, the terms used in the following claims should not be construed to limit the technology to the specific embodiments disclosed in the specification, unless those terms are explicitly defined herein. Accordingly, the actual scope of the technology encompasses not only the disclosed embodiments, but also all equivalent ways of practicing or implementing the embodiments. The language used in the specification has been principally selected for readability and instructional purposes. It may not have been selected to delineate or circumscribe the subject matter. It is therefore intended that the scope of the technology be limited not by this Detailed Description, but rather by any claims that issue on an application based hereon. Accordingly, the disclosure of various embodiments is intended to be illustrative, but not limiting, of the scope of the technology as set forth in the following claims.

11857261

DETAILED DESCRIPTION In the following discussion that addresses a number of embodiments and applications of the present invention, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized, and changes may be made without departing from the scope of the present invention. Various inventive features are described below that can each be used independently of one another or in combination with other features. However, any single inventive feature may not address any of the problems discussed above or may only address one of the problems discussed above. Further, one or more of the problems discussed above may not be fully addressed by any of the features described below. As used herein, the singular forms “a”, “an” and “the” include plural referents unless the context clearly dictates otherwise. “And” as used herein is interchangeably used with “or” unless expressly stated otherwise. As used herein, the term “about” means+/−5% of the recited parameter. All embodiments of any aspect of the invention can be used in combination, unless the context clearly dictates otherwise. Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”. Words using the singular or plural number also include the plural and singular number, respectively. Additionally, the words “herein”, “wherein”, “whereas”, “above”, and “below” and the like shall refer to this application as a whole and not to any particular parts of the application. Notably “light” is variously referred to herein as “illumination”, “illumination beam”, “visual wavelength”, “color”, and the like. The description of embodiments of the disclosure is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. While the specific embodiments of, and examples for, the disclosure are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the disclosure, as those skilled in the relevant art will recognize. FIG.1Aillustrates the case when an imaging head of a conventional contact type eye imaging device is being positioned close to the eye of a patient. A light coupling medium may be used to bridge the gap between the end of the imaging lenspiece and the cornea of the patient eye. The left diagram shows how the lenspiece is held for imaging the retina and the right diagram shows how the lenspiece is held for imaging the anterior chamber. Relatedly,FIG.1Bdepicts respectively the sketch of a wide-angle retina image (left) and the sketch of an anterior chamber image (right). The present invention is an improvement in that it can enable the capture of a retinal image with a wide angular field of view (up to 130 degrees in some embodiments) with substantially improved illumination uniformity. To achieve this, as one of the requirements, there is a need for an optical coupling medium to bridge the gap between the front most optical element and the cornea of a patient eye. When the light coupling medium makes contact with the cornea of the patient eye and the volume of the light coupling medium fills the space between the device and the eye, the light coupling medium will bridge the gap and optically enhance light transmission. This also helps to eliminate a significant amount of optical aberrations originating from the cornea of the eye.FIG.1Afurther shows that light coupling medium permits imaging light to easily transmit through the gap, thereby facilitating ophthalmological examination. FIG.2Ashows an embodiment of the presently invented eye-imaging apparatus1001including a handpiece and a lenspiece connected to each other.FIG.2Bshows the imaging path optical elements (1004,1006,1008and1010) of a lenspiece and a front part of the illumination path optical elements (an array of optical fibers1002positioned next to a contact lens1004with the fibers skewed at an angle relative to the image path optical axis1011) of the lenspiece. Illuminator fibers1002generally comprise light-transmitting fibers. In some embodiments, plastic multimode optical fibers like the Toray RAYTELA Polymer Optical Fiber PQE-FB 750 are used that have a diameter of 0.75 mm and an NA (numerical aperture) of 0.64. While plastic fibers are mentioned, optic fibers of any type are contemplated and included within the scope of the invention, including glass fibers. The skewed circularly arrayed fibers1002are arranged next to each other at the front of the conic lens1006. The maximum number fibers of the array1002that can be arranged next to each other at the front of the conic lens1006is dependent on the fiber diameter, the half cone angle and the front diameter of the conic lens1006, and the skew angle of the fibers relative to the optical axis1011. In one embodiment, the front diameter of the conic lens1106is about 3.5 mm, the half cone angle of the conic lens1006is about 30 degrees, the skew angle of the fibers1002relative to the optical axis1011is about 40 degrees, and 16 fibers are arranged at the front of the conic lens1006next to the contact lens1004. Such a design will ensure that Purkinje reflections of the illumination light are substantially directed away from entering the imaging path. At the same time, the illumination ring at the iris plane can be relatively small (less than 4.5 mm in the outer diameter of the annular illumination ring there) so the required minimum pupil dilation size for good illumination is about 4.5 mm only. FIG.2Cshows a micro prism array film based light intensity profile redistribution element (referred to hereafter as, “MPAR”)1012that is disposed between the light-transmitting fibers1108and light-receiving fibers1002at the intersection of the handpiece and the lenspiece. In one embodiment, MPAR1012is arranged on the lenspiece side (the right side), optically in connection with the transmitting fibers1108on the handpiece side. The arrangement enables illumination light to be initially guided through the transmitting fibers1108, angularly redistributed as light passes through the MPAR1012, and then received at a receiving end by the receiving fibers1002. As a result, when light emits from an emitting end at the other side of the receiving fibers1002, the light intensity angular distribution is changed relative to that from the transmitting fibers1108. In some embodiments, the present invention contemplates optic fiber with a large Numerical Aperture (NA), numerical aperture being the characterization of the range of angles over which the optic fiber receives and emits light. For example, receiving fibers1002and transmitting fibers1108may be fibers with numerical aperture of at least 0.60 NA. In some embodiments, the receiving and transmitting fibers1002,1108may have numerical apertures of 0.64 NA. In one embodiment, the illumination light path initially has a total of 30 plastic fibers that receive light from a light source like an LED light box. These fibers can be in the form of a light guide cable to transmit light to the handpiece, and inside the handpiece it is then split into two sub-cables, each with 15 fibers. At the optical interconnect from the handpiece to the lenspiece, each 15-fiber-port from the handpiece is connected to an 8-fiber-port in the lenspiece and as a result, mechanical connection tolerance is built into the design to ensure relatively consistent light transmission and/or coupling efficiency from the handpiece to the lenspiece. Further to the above, in one embodiment, the fibers in the lenspiece, especially the portion near the tip of the lenspiece, may have absorptive material positioned on the sides thereof, with the fiber ends being free of absorptive material by perpendicularly cutting or cleaving or lapping/polishing the fiber ends. This ensures that no light escapes from the sides of the fibers to create background optical noise in the captured image. In some embodiments, a black paint may be applied to the sides of the end of the fibers. Alternatively, the use of black or light absorbing tubing to encompass the front section of the lenspiece optical fibers can provide the same function as the black paint coating. Doing so will substantially suppress scattered illumination light at the fiber end sections from being channeled to the imaging path, therefore preventing haze or glow at the periphery in the final fundus or retina image. This approach also improves the manufacturability of the lenspiece. In some embodiments a portrait lenspiece is provided (i.e., a separable lenspiece) for taking an external image of the patient's eye or face. When taking a picture of the patient's face there is no need for the spherical field curvature corrections as in the case of optically relaying a concave spherical retina to a flat image sensor. In such a case, the MPAR may or may not be needed on the portrait lenspiece side as illumination uniformity requirement for external patient eye or face imaging is not as critical as in the case of retina or fundus imaging. In general, light coupled into a multimode optical fiber and then emitted from the fiber will have a bell-shaped angular optical power or intensity distribution1017, with more power or intensity distributed around the central angular range of the light emitting cone (i.e. contained among the lower order modes). To convert a bell-shaped angular distribution to a more hat-top or square shaped angular distribution1019, the thin prism array film (MPAR)1012in between the illumination light path of the handpiece and the lenspiece serve the transfer function. As shown inFIG.2C, the angular light distribution shape changes from that of a bell shape1017when light emits from the handpiece fibers to that of a hat-top shape1019when light emits from the lenspiece fibers. As a result, the illumination light from a skewed circular array of fibers when landing on the retina can span a wide enough range with substantially improved illumination uniformity. When compared to the prior art, the optical energy will spread more to the peripheral and the center of the retina while also more uniformly covering the desired angular field of view. Returning toFIG.2A, a wide angular field of view retina or fundus imaging lenspiece is shown attached to a handpiece according to one embodiment of the present invention. Notably, the device can be held next to the cornea of a patient eye and with light coupling gel, a wide angular field of view fundus image may be captured. In some embodiments, different lenspieces that are designed to image the retina or fundus with different angular field of views (when each of them is attached to the handpiece) may be used.FIG.6shows the optical designs of different lenspieces with different angular field of views being connected to the same handpiece to form different angular field of view retina or fundus images of the same infant eye. FIG.2Bshows the optical elements at the front portion of a wide angular field of view lenspiece. Some embodiments of the present invention are such that the angle at which the light emanates from the tip of any given fiber along a light output pointing line of the fiber (being a central line of the light-emitting cone of the fiber) functions to minimize Purkinje reflections being channeled back to the imaging path. As an embodiment of the present invention, the array of illuminator fibers1002that terminate next to the front optical element (the contact lens)1004are arranged in a skewed manner. In other words, the circular fiber array ends at a skew angle relative to the lenspiece imaging path optical axis1011so the fibers are not on a meridional plane of the optical axis1011of the imaging path optical lenses, i.e. at a skewed angle relative to the optical axis1011. Concordantly, the illuminator fibers1002may also be arranged such that the light output pointing lines thereof are at a skewed angle relative to each other. The imaging path optical lenses may comprise a contact lens1004, a conic lens1006, a mid-position singlet1008, and a back position doublet1010. The contact lens1004may be positioned optically proximal of and in contact with the conic lens1006, the conic lens1006is positioned optically proximal of the singlet1008, and the singlet1008is positioned optically proximal of the doublet1010. In some embodiments, the skew angle relative to the optical axis1011may be at least 30 degrees, at least 35 degrees, or at least 40 degrees. Importantly, none are on or across the meridional plane of the optical axis1011in said embodiments. Notably, the gap between the contact lens1004and the nosepiece (the front endcap housing, not known in the Figure) of the lenspiece may be sealed in the preferred embodiment, preventing liquid ingress to the lenspiece from its front end. With this skewed fiber angle arrangement, when the illumination light rays hit the front and back surfaces of the cornea and the ocular lens, most of the illumination light rays will be specularly reflected by these surfaces to not enter the imaging path and as a result will not land on the image sensor to produce background optical noise. In other words, when the illumination light beams hit the four Purkinje surfaces, the specularly reflected light rays are mostly directed away from the imaging path. As such, Purkinje images are mostly directed away and minimally captured by the image sensor. FIG.2Cshows the illumination path optical elements at the interconnect portion between the lenspiece and the handpiece. As an embodiment of the present invention, along the illumination path at the intersection, a micro prism array film based light intensity profile redistribution element1012in the form of a micro-prism array film (MPAR) is disposed between the illumination light receiving fibers1002on the lenspiece side and the transmitting fibers1108on the handpiece side. In some embodiments, plastic optical fibers with high numerical apertures (for example, NA=0.64) are used. An optical window1016is provided on the lenspiece side to protect the MPAR1012and the fibers1002. In some embodiments, a glass rod based optical homogenizer1014is used on the handpiece side to both homogenize the illumination light and to protect the illumination optical fibers1108in the handpiece. Because there are multiple optic fibers in each fiber cable or sub-cable that can cause light intensity hot spots, by sending all the illumination light through a specialized glass rod homogenizer, said light can thus achieve enhanced uniformity in spatial light intensity distribution. For example, a rod may be within a range of 3-4 mm wide or in diameter and 10 mm long. An optical window1016is positioned between the MPAR1012and the optical fibers1002to protect the MPAR1012and the optical fibers1002in the lenspiece. In general, light coupled into a multimode optical fiber and then emitted from the fiber will have a bell-shaped angular optical power distribution, with more power distributed around the central angular region of the light emitting cone (i.e. contained among the lower order modes). To convert a bell-shaped distribution1017to a more hat-top or square-shaped distribution1019, the MPAR1012is used in between the handpiece and the lenspiece. The angular light distribution shape changes from that of a bell shape1017when light emits from the handpiece fibers1108to that of a hat-top shape1019when light emits from the lenspiece fibers1002after the transmission of the illumination light from the handpiece side to the lenspiece side. As a result, the illumination light from the skewed circular array of fibers1002(as shown inFIG.2B) when landing on the retina can span a wide enough range with optical energy spreading more to the peripheral and the center of the retina than the bell shape distribution to more uniformly cover the desired angular field of view. In some embodiments, in order to spread the light more evenly across the retina, a film is used containing a prism material. The film is adhered with glue or the like, and the glue has an index of refraction of the right choice that further helps to spread the light with the desired angular spreading range. The MPAR1012may be the 3M™ BRIGHTNESS ENHANCEMENT FILM BEF4 GT 90/24 with a refractive index of 1.66, and the glue on the prism side may be transparent with a refractive index of 1.348. As a result, when an illumination light ray hits the glue from the prism array side, it is guided sideways, spreading out with an additional deflection angle. In some embodiments, as shown inFIG.2C, the prism array1012induces the distribution of light to transform from a bell curve to more square-like curve. Referring toFIG.3, the dashed rectangular box represents a handpiece1102. Inside the handpiece1102is a visual wavelength image sensor1104which can be connected to a live video display (not shown), a color splitting prism block or an optical path length compensation block1103, a deep red and/or near infrared cut filter1105, an axially movable lens combination1106. The lens combination1106focuses and relays a real image from somewhere at or near the intermediate image plane1101to the image sensor1104. Inside the handpiece, there is also an illumination light path comprising a number of fibers1108(which can be the same fiber as the fiber1002in the lenspiece), that can be bundled to one or more light emitting ports and terminate at the front end of the handpiece. Notably as shown inFIG.4, in some embodiments, the imaging relay from the retina of a patient eye2302to the intermediate image plane2101is accomplished by the lenspiece, and from there the image is focused to the image sensor1104. As discussed, fibers1002or1108may include the use of plastic fibers with high numerical aperture (NA). In some embodiments, the other ends of the fibers1108(also referred to herein as “illuminator fibers”) can be bundled together and optically connected to a white or broadband wavelength light source, or a single-color wavelength light source. The fibers1108are configured to collect and couple the illumination light from the light source(s) and transmit the illumination light along the illumination path in the handpiece. The light source1110may be located outside or inside the handpiece. In another embodiment, the use of fibers with high numerical aperture (NA) are contemplated. An example is the TORAY RAYTELA PQE series plastic fibers that have a numerical aperture of 0.64. Said fibers ultimately provide illumination light to the lenspiece and then from a skewed circular array of fibers at the end of the lenspiece to span a wide enough range to cover the desired angular field of view on the retina of a patient eye. Referring toFIG.4, the handpiece can be combined with any lenspiece of a certain angular field of view coverage designed to be used with the presently disclosed system as long as the lenspiece can form a real intermediate image at or near the intermediate image plane in front of the handpiece. In addition, in the preferred embodiment the lenspiece and handpiece achieve a wide angular field of view (“FOV”) of up to 130 degrees relative to the center of the eye globe. As illustrated inFIG.4, a 130-degree FOV lenspiece is shown attached to the handpiece as an example. On the right side of the handpiece, a cone-shaped housing2202represents the body of a 130-degree FOV lenspiece. Inside the lenspiece, there is a lens combination element2204and an illumination light path2206comprising a number of fibers optically coupled with those fibers in the handpiece. The front optical element2208can function both as a front contact lens of the lens combination2204for forming an intermediate image of an object at or near the intermediate image plane2101and as a transmission window for the illumination light as well as an optical sealing window. In some embodiments, the handpiece and lenspiece comprise an angular FOV of at least 110 degrees relative to the center of the eye globe. In other embodiments, the handpiece and lenspiece comprise an angular FOV of at least 120 degrees relative to the center of the eye globe. Continuing withFIG.4, a human eye2302is shown at the far right, with the lenspiece positioned next to the cornea and a light coupling medium (gel) filling the gap between the front contact lens2208and the human eye2302. At this position, the illumination light beams coming from the ends of the optical illuminator fibers2206enter the eye with a skewed beam direction or angle and a flattened angular light intensity distribution, as well as a cone angle (or numerical aperture) large enough to illuminate the desired area on the retina of the eye2302. In some embodiments, variation in angle of the lenspiece relative to the eye allows various views for optical examination. Notably, with a certain coupling gel gap distance the light rays will pass through the cornea outside the imaging path but can still enter the eye without being blocked by the iris of the human eye2302. Standard gel gap tolerance ranges apply with respect to the cornea and the front contact lens2208. For example, the gel gap distance can be from 0.5 mm to 1.0 mm In some embodiments, the illumination uniformity variation as detected on the image sensor is less than or equal to at least twenty five percent. This illumination variation is greatly reduced relative to conventional systems, which typically result in at least fifty percent variation resulting from generally a donut shaped illumination annular ring. Referring now toFIG.5, there is shown the case of a portrait lenspiece3202attached to the handpiece1102. Inside the portrait lenspiece is a lens combination3204that can form an intermediate real image of the object (an external image of a patient eye as shown inFIG.5) at or near the intermediate image plane3101. There is also an illumination light path3206comprising a number of fibers or fiber bundles that relay the illumination light from the handpiece to the portrait lenspiece and exit the portrait lenspiece to flood illuminate an object. In this case, there is a relatively large air gap between the portrait lenspiece3202and the patient eye3302, and no coupling gel is used. The illumination light from the optical illuminator fibers3206can be bundled into four light emitting ports and spread to illuminate the external of the patient eye3302. Depending on the air gap distance, a larger or smaller external feature of the patient eye or the patient face may be illuminated and digitally imaged. In some embodiments, as shown inFIGS.7A-C, the lenspiece3202and handpiece1001include detailed exterior and interior core elements essential to the functioning of the eye imaging apparatus. For example, as shown inFIG.7B, the lenspiece3202and handpiece1001include a contact lens2208, cone shaped lens2207, intermediate image plane1101, FA filter/optic window2400, focus group2402, aperture stop2404, IR block filter2406, color splitting prism spacer block2408, and image sensors2410. As described herein, the present invention contemplates optical fibers with high numerical aperture (NA), skewed pointing angles, and light spatial intensity distribution conversion. As a result, the illumination light can span a wide enough range with desired intensity distribution to cover the desired angular field of view on a retina. As described above, in order to convert a bell-shaped distribution to a more top-hat or square-shaped distribution, a thin prism array film based light intensity distribution convertor is used in coupling the illumination light between the handpiece and the lenspiece. By pointing the circular fiber array ends such that light output pointing lines thereof are at a skew angle relative to the lenspiece imaging optical axis, illumination light specularly reflected back from the optical interfaces of the cornea and the ocular lens can be directed away from the imaging path to substantially reduce optical background noise on the image sensor. The foregoing description of the present invention has been presented for the purpose of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teachings. It is intended that the scope of the present invention not be limited by this detailed description, but by the claims and the equivalents to the claims appended hereto.

11857262

DETAILED DESCRIPTION There is a need to effectively monitor intraocular pressure within a patient's eye in order to detect, or monitor the progression of, glaucoma. Intraocular pressure can be measured non-invasively using, for example, a tonometer. While tonometers have the advantage of being non-invasive, they have the disadvantages of generally being expensive, non-portable, specialized equipment that requires skilled operation. Accordingly, as a practical matter, it is difficult to use a tonometer to effectively monitor intraocular pressure in a patient's eye with time resolution greater than one measurement every few days or weeks. However, since intraocular pressure can vary significantly over relatively short periods of time, such relatively sparse intraocular pressure measurements may not provide a complete or accurate picture of the patient's risk for glaucoma. It would, therefore, be advantageous to be able to measure intraocular pressure more often or even continuously. FIG.1Ais a schematic illustration of an implantable intraocular physiological sensor200located in a human eye100. For reference, various anatomical features of the eye100are labeled inFIG.1. For example,FIG.1Ashows the vitreous humor102, the iris104, the lens106, the pupil108, the anterior chamber and aqueous humor110, the cornea112, the retina114, and the optic nerve116.FIG.1also illustrates an intraocular physiological sensor200that is located within the anterior chamber of the eye. The intraocular physiological sensor200is capable of measuring, for example, intraocular pressure within the eye. The intraocular physiological sensor200can also, or alternatively, be designed to measure any of several other physiological characteristics, as discussed herein. It should be understood that the intraocular physiological sensor200is not necessarily drawn to scale. In addition, the sensor200could be positioned at several different locations within the eye. For example, the intraocular physiological sensor200could be fixedly attached or anchored to any suitable anatomical feature of the eye, including but not limited to the sclera or iris, depending upon the particular application. As discussed further below, the intraocular physiological sensor200could be fixedly attached or anchored to or within a physiological aqueous humor outflow pathway. The physiological aqueous humor outflow pathways include the “conventional” pathway comprising the trabecular meshwork and Schlemm's canal; and the “uveoscleral” pathway comprising the ciliary body, the sclera, and the supraciliary/suprachoroidal space.FIG.1Billustrates the location of the sensor200fixed by an anchor201through meshwork tissue117embedded into scleral tissue118in the iridocorneal angle119. FIG.1Cillustrates the location of the sensor200fixed by an anchor201within the supraciliary/suprachoroidal space between the ciliary body/choroid and the sclera118. The ciliary body115is contiguous with the choroid115a. The supraciliary/suprachoroidal space is normally a potential space at the interface between the ciliary body/choroid and sclera. The space may open to accommodate an implant such as the sensor200and/or the anchor201. The supraciliary/suprachoroidal space is thus identified schematically by the hatching121inFIG.1C.FIG.1Cillustrates an example of placement of the intraocular physiological sensor200(which may be partially or completely located within the anterior chamber110; or may be partially or completely located within the supraciliary/suprachoroidal space121) and the anchor201. In other embodiments, the physiological sensor that is implanted within the supraciliary/suprachoroidal space could be configured such as the sensor500shown inFIG.5A. Alternatively, the sensor200could be attached to some other ocular implant, such as an intraocular lens. Regardless of location, care should be taken to avoid contact of the sensor with the corneal endothelium. The intraocular physiological sensor200may also, or alternatively, measure glucose concentration in the aqueous humor110. There is a need to measure glucose concentration within the human body as a means to treat or prevent complications from diabetes. Typically, glucose is measured from the blood or urine. Some implantable glucose sensors have been developed that measure glucose from interstitial fluids. However, the body may have a negative immunological response to such implants, which may degrade the performance of the sensor over time. However, the eye, especially the anterior chamber of the eye, is an immunologically-privileged site within the body. Thus, an implantable sensor for measuring glucose within the eye could have advantages over other implantable sensors that are made to measure glucose in non-immunologically privileged parts of the body. In addition, although the glucose concentration within the aqueous humor may not be identical to blood glucose concentration, the two may be correlated such that a measurement of glucose concentration in the aqueous humor can be predictive of blood glucose concentration. For some embodiments, such as intraocular pressure sensors, it may be possible to implant the sensor portion completely within the supraciliary/suprachoroidal space. In some embodiments, a modest level of fibrosis may not interfere with satisfactory functioning of the implanted sensor. As already mentioned, in some embodiments, the intraocular physiological sensor200measures both intraocular pressure and glucose concentration in the aqueous humor. This can be advantageous because the glucose concentration measurement can be used to diagnose and/or treat diabetes. Meanwhile, diabetes patients are also at higher risk of developing glaucoma. Thus, there may be a significant overlap of the patient population for whom intraocular pressure and glucose concentration measurements would be valuable. In some embodiments, the intraocular physiological sensor200is wholly or partially powered using a fuel cell that converts a substance found in the human body into, for example, electrical power. For example, in some embodiments, the fuel cell is an electrochemical fuel cell that produces electricity using the glucose dissolved in the aqueous humor. Thus, the glucose itself acts as a renewable fuel for powering the physiological sensor200. In contrast, other implantable physiological sensors may be wholly dependent upon batteries or an external source for their power. However, in the case of battery-operated implantable physiological sensors, the capacity of the battery may tend to limit the useful lifetime of such implantable sensors. If the useful lifetime provided by the battery is not adequate for a given application, the implantable sensor may need to be replaced. This is disadvantageous because insertion of an implantable sensor is an invasive process and may require surgery with all of its attendant risks. Alternatively, some implantable physiological sensors rely upon external devices for power (e.g., for real-time operation using the externally-supplied power or to re-charge an internal battery). For example, an implantable physiological sensor may be externally powered via inductive coupling or RF energy from an external device. However, even though such an external power source may remove or reduce the reliance of the implantable physiological sensor's useful lifetime on a battery, external power sources may also introduce other undesirable operating limitations. For example, the time resolution of measurements from such implantable sensors may be limited if measurements can only be performed while the sensor is externally-powered. Therefore, the fuel cell-operated intraocular physiological sensor200is advantageous because it may be expected to have a greater useful lifetime than sensors that are wholly reliant upon a battery or external device for operating power. In addition, such implantable sensors could be used to perform measurements relatively more often, or even continuously. FIG.2is a block diagram of the implantable intraocular physiological sensor200. In some embodiments, the implantable intraocular physiological sensor200includes an electrochemical fuel cell210and power supply electronics220. The implantable intraocular physiological sensor200may also include a battery240that is charged by the electrochemical fuel cell210. In some embodiments, the implantable intraocular physiological sensor200includes a physiological characteristic sensing module250, a measurement storage module260, a controller module270, and a transmitter module280with an antenna285. Each of the components of the implantable intraocular physiological sensor200may be wholly or partially housed in a biocompatible housing290. It should be understood that, although the implantable physiological sensor200is described primarily herein with respect to intraocular applications, it may also be used in parts of an organism other than an eye. In embodiments of the physiological sensor without a fuel cell, there may be an on board power supply such as a battery, or a solar cell combined with a battery or storage capacitor. The battery may be a rechargeable battery that can be recharged by an external device (e.g., a device used to download physiological measurements). In other embodiments of the physiological sensor without a fuel cell, power may be provided by inductive or RF means. In still other embodiments of the physiological sensor without a fuel cell, the sensor may comprise a component of a passive resonant circuit which is interrogated by an external instrument, such as described in “Microfabricated Implantable Parylene-Based Wireless Passive Intraocular Pressure Sensors,” by P-J Chen et al., in Journal of Microelectromechanical Systems (2008), volume 17, which is incorporated herein by reference in its entirety. The physiological characteristic sensing module250is a component that performs measurements of a physiological characteristic of interest. For example, the physiological characteristic sensing module250outputs a signal (e.g., an electrical signal) that is quantitatively representative of the physiological characteristic under measurement. As discussed herein, the physiological characteristic sensing module250may be designed to measure intraocular pressure. There are several different tonometric devices for measuring intraocular pressure. Some sensors are described in U.S. Pat. No. 7,678,065, which is incorporated by reference herein in its entirety. The physiological characteristic sensing module250can make use any of these, or future-developed devices. Alternatively, the physiological characteristic sensing module250can be designed to measure intraocular glucose concentration. In still other embodiments, the physiological characteristic sensing module250can be designed to measure any of the biomarker substances in Table 1, which are listed with the corresponding physiological condition of which they may be indicative. TABLE 1Detected BiomarkerCorresponding ConditionInterleukin-2, interleukin-6,Uveitisinterleukin-10, interleukin-12,interferon-y, tumor growthfactor-β2, tumor necrosisfactor-α, macrophage migrationinhibitory factor8-Hydroxy-2′-deoxyguanosineAge-Related MacularDegeneration (AMD)aB-crystallin, a-enolase, andAMDglial fibrillary acidic proteinPentosidine, and N-carboxymethyl-Diabetic RetinopathylysineMonocyte chemoattractant protein-1Diabetic Macular Edemaand interleukin-8(DME)Interphotoreceptor retinoid-bindingBlood-Retinal Barrierprotein(BRB) breakdown/inflammationSurvivinRetinoblastoma/oculartumorVEGFOcular ischemiaAmyloid-βAlzheimer'sIntercellular adhesion molecule-1DME(ICAM1)TNF-αGlaucomaTGF-beta3GlaucomaTransforming growth factor-beta2Glaucoma, diabetes In some embodiments, the implantable physiological characteristic sensing module250may include a temperature sensor for temperature correction of the physiological sensor200; and/or may include an oxygen sensor for correcting the physiological sensor200for the partial pressure of oxygen. In some embodiments, the intraocular physiological sensor200may comprise a fluorescent sensor, such as disclosed in U.S. Pat. No. 7,653,424 and U.S. Patent Application 2007/0030443, which are incorporated herein by reference in their entirety. In these embodiments, the implanted sensor200may not require an onboard power supply, and may be interrogated by an external device. In some embodiments, the implantable intraocular physiological sensor200includes multiple instances of the physiological characteristic sensing module250. Each instance of the sensing module250may be used to measure a different physiological characteristic. As discussed herein, in some embodiments, the physiological sensor200includes two sensing modules250for measuring intraocular pressure and glucose concentration. Again, the physiological characteristic sensing module(s)250can use any known or later-developed device for measuring the foregoing substances, or any other physiological characteristic of interest for a particular application. In some embodiments, the physiological characteristic sensing module250is controlled (e.g., by the controller module270) to perform a measurement at regular intervals. For example, the sensing module250may perform a measurement at least hourly, at least every 15 minutes, at least every minute, or at other intervals, depending upon the particular application. In some embodiments, the physiological characteristic sensing module250performs measurements substantially continuously. In this way, trend data regarding the physiological characteristic of interest can be collected so as to provide a more useful or complete picture of how the physiological characteristic changes as a function of time. Alternatively, in some embodiments, readings could be taken less frequently throughout the day (e.g., 4-6 times per day vs. continuously or every 15 minutes) in order to conserve energy (e.g., battery life). The implantable intraocular physiological sensor200may also include a transmitter module280that is communicatively coupled to an antenna285for wirelessly transmitting measurements from the physiological characteristic sensing module250to an external device. In some embodiments, the transmitter module280may be replaced by a transceiver module which is capable of also receiving communications (e.g., control commands) from the external device. Any type of suitable transmitter or transceiver device that is known or developed in the future can be used. In some embodiments, the physiological characteristic sensing module250may comprise an electrical circuit that develops a resonant frequency as a function of the level of physiological characteristic, wherein the resonant frequency can be determined with an external device. In this kind of embodiment, the module250may employ an antenna for wireless communication, but not necessarily a transmitter (see, for example, Microfabricated Implantable Parylene-Based Wireless Passive Intraocular Pressure Sensors, by P-J Chen et al., in Journal of Microelectromechanical Systems (2008), volume 17, which is incorporated herein by reference in its entirety). In some embodiments, the physiological characteristic sensing module250and/or transmitter module280may comprise an optical (such as infrared) emitter and/or detector for wirelessly transmitting measurements to, and/or receiving instructions from, an external device. The transmitter module280may be controlled (e.g., by the controller module270) to transmit measurements at, for example, predetermined intervals, continuously, or upon command from the external device to which the data is being transmitted. In some embodiments, the external device to which measurement data are transmitted may be a data logger that is worn by the patient for storing the measurements until they can be downloaded by a clinician. In other embodiments, the external device may be a handheld reader device used by a clinician to periodically download measurement data that is stored internally by, for example, the measurement storage module260. The reader device can then transmit the downloaded measurements to a computer (e.g., via the Internet or some other communication network) for processing and/or for analysis by a clinician. In some embodiments, the transmitter module280transmits glucose concentration measurements to an insulin pump that is worn by the patient. Such measurements can be used by the insulin pump to control the injection of insulin into the patient's body. The reader device can also provide the downloaded measurements to the patient via a user interface. In the case of glucose concentration measurements, for example, the patient case use the measurements to manage his or her diet and/or exercise. The implantable intraocular physiological sensor200may optionally include a measurement storage module260. The measurement storage module260can be used to internally log measurements from the physiological characteristic sensing module250, for example, until they can be retrieved by an external device that is communicatively coupled to the measurement storage module260via the transmitter module280. The measurement storage module260can be, for example, a solid-state electronic memory device. In some embodiments, the physiological sensor200is configured to download, for example, a day or other time period's worth of measurements (e.g., IOP measurements) at a time to an external receiver located, for example, at the bedside of the patient. Data could also be downloaded more or less frequently than daily. In some embodiments, the downloading of data is an automated process. Once measurement data is downloaded to an external device, it can be transferred to a remote reading center for preparation of reports for the patient's ophthalmologist or other managing physician. In addition, the intraocular physiological sensor200could include a storage module configured to store other data besides, or in addition to, physiological measurements. For example, the storage module could be loaded with the patient's electronic medical record data, or any other private or sensitive data. In some embodiments, an implantable intraocular device may forgo physiological sensing capabilities and be used primarily to provide a storage module for storing data in a secure but easily accessible, immunologically privileged location. For example, the storage module could hold identification information associated with the patient for security purposes. This information could be accessed, for example, using an external reader to interrogate the implanted device, as discussed herein The implantable intraocular physiological sensor200also includes a controller module270. The controller module270can be used, for example, to perform control operations for the other components of the physiological sensor200. In some embodiments, the controller module270may provide commands to the physiological characteristic sensing module250to perform measurements. The controller module270may also control the writing and reading of data to the measurement storage module260and the operation of the transmitter module280. In addition, the controller module270may control power settings of the electrochemical fuel cell210, the power supply electronics220, and battery240. As discussed further below, the interconnecting lines shown inFIG.2primarily represent power supply connections. It should be understood, however, that signal and/or command lines can be provided between any and all of the components of the sensor200(e.g., between the controller module270, the physiological characteristic sensing module250, the measurement storage module260, the transmitter module280, and/or the power supply electronics220, etc.) as necessary. The controller module270may also perform other functions. For example, in some embodiments, the controller module270can perform data processing tasks on the measurements collected by the physiological characteristic sensing module250, though in other embodiments any such required data processing can be performed by an external device after downloading the measurements in order to avoid the power demands of such onboard processing. In addition, the controller module270may monitor the collected measurements and output alarm signals (e.g., to an external device via the transmitter module280) if the physiological characteristic that is being monitored reaches some threshold value or if immediate notification is otherwise considered necessary. For example, an alarm signal can be triggered if the sensor detects a potentially dangerous low blood sugar level. The controller module270can also perform measurement data compression (to allow for more measurements to be stored on the measurement storage module260). In addition, the controller module270can issue commands to other components of the physiological sensor200(e.g., the transmitter module480, the measurement storage module460, the physiological characteristic sensing module450, etc.) to shut down or enter a power-saving state when not in use. As briefly discussed above, the implantable intraocular physiological sensor200may include a fuel cell such as the electrochemical fuel cell210. In some embodiments, the electrochemical fuel cell210uses glucose in the aqueous humor108to produce electrical power from a chemical reaction with the glucose. The electrical power produced by the electrochemical fuel cell210can be used to satisfy the power demands, whether in whole or in part, of any or all of the other components of the implantable intraocular physiological sensor200. An electrical bus230is illustrated inFIG.2. The electrical bus230is energized by the electrochemical fuel cell210(e.g., via power supply electronics220and/or a battery240). Any other components of the implantable intraocular physiological sensor200can be connected to the electrical bus230(as illustrated by the interconnecting lines inFIG.2) to receive operating power, as necessary. The electrochemical fuel cell210can be connected to power supply electronics220. The power supply electronics220can include, for example, a voltage regulator, a voltage converter, or any other electrical component that may be desirable for conditioning the electrical power output by the electrochemical fuel cell210so that it can be satisfactorily used by other electrical components within the implantable intraocular physiological sensor200. In some embodiments, the electrochemical fuel cell210can be used to charge a battery240. A battery240may be useful, for example, in cases where data transmission from the transmitter module280requires a burst of power that is greater than the instantaneous power available from the electrochemical fuel cell210. The battery240may also be useful in providing a steady level of electrical power to other components of the implantable intraocular physiological sensor200in circumstances where, for example, the supply of fuel (e.g., glucose) used by the fuel cell210is irregular. Although the implantable intraocular physiological sensor200includes the electrochemical fuel cell210to at least partially satisfy power demands, it should be understood that the presence of the fuel cell210does not necessarily preclude the use of other internal or external power sources to provide additional operating power to the physiological sensor200. Moreover, in some embodiments, the intraocular physiological sensor200may include two or more batteries in addition to, or in place of a fuel cell. In such embodiments, one battery can become active after another becomes too discharged for further use, thus extending the useful life of the sensor. The changeover between batteries can be controlled, for example, by software and/or hardware. According to some estimates, the average power consumption of the physiological sensor200may be less than about 10 nW, assuming that a measurement is made by the physiological characteristic sensing module450every 15 minutes and that the transmitter module480performs data transmission once daily. Thus, in some embodiments, the electrochemical fuel cell210has an average power output of at least about 10 nW. However, if, for example, measurements or data transmission are performed more frequently, or if more than one physiological characteristic is monitored, etc., then power demands may be greater. Therefore, in some embodiments, the electrochemical fuel cell210produces an average power output of at least about 10 μW, or more. The implantable intraocular physiological sensor200may also include other modules in addition to those that are specifically illustrated. For example, the implantable intraocular physiological sensor200could include a Global Positioning System (GPS) module for providing location information about the patient's whereabouts. The GPS module could, for example, store a reading of the patient's location at each time that a physiological measurement is performed. The location information could be downloaded from the physiological sensor200along with physiological measurements and used, for example, to access a weather database with barometric pressure information from the patient's location. Such barometric pressure information can then be used to perform any necessary corrections to the intraocular pressure measurements that were detected by the physiological sensor200. FIG.3is a block diagram of an implantable intraocular physiological sensor300in which a physiological characteristic is measured based on the output from an electrochemical fuel cell310. The implantable intraocular physiological sensor300can include, for example, an electrochemical fuel cell310, power supply electronics320, an electrical bus330, a battery340, a physiological characteristic sensing module350, a measurement storage module360, a controller module370, a transmitter module380coupled to an antenna385, and a biocompatible housing390. Each of these components can be similar to the corresponding components described with respect toFIG.2. In the implantable intraocular physiological sensor300, the physiological characteristic sensing module350measures the amount of the substance (e.g., in the vicinity of the physiological sensor300) that is used by the electrochemical fuel cell310to generate power. For example, the electrochemical fuel cell310may be a glucose fuel cell and the sensing module350may be designed to measure glucose concentration in the aqueous humor. In this embodiment, the sensing module350is shown with a direct connection to the electrochemical fuel cell310to indicate that the sensing module350measures glucose concentration based upon the electrical current or voltage that is output by the electrochemical fuel cell310. For example, when glucose is present in the aqueous humor of the eye in greater concentrations, the electrochemical fuel cell310may produce a larger electrical current or voltage, and vice versa for smaller glucose concentrations. The glucose measurement provided by the physiological characteristic sensing module350may be, for example, proportional to the electrical current or voltage from the fuel cell310. FIG.4is a block diagram of an implantable intraocular physiological sensor400that includes an electrochemical fuel cell410and/or a solar cell415. The electrochemical fuel cell410, power supply electronics420, electrical bus430, battery440, physiological characteristic sensing module450, measurement storage module460, controller module470, transmitter module480and antenna485, and biocompatible housing490can be similar to the corresponding components described with respect toFIGS.2and3. The implantable intraocular physiological sensor400can also include a solar cell415. The solar cell415generates power from any light that enters the eye100. The solar cell415, which can be of any suitable type currently known or developed in the future, can be used to at least partially satisfy power demands of the various components of the physiological sensor400. For example, if the electrochemical fuel cell410is unable to satisfy the power requirements of the physiological sensor400, then the solar cell415can be used as an additional power source to help satisfy those requirements. In some embodiments, the solar cell415is used to energize an electrical bus430(e.g., via the power supply electronics420) to which other components of the physiological sensor400are connected. The solar cell415can also be used to charge a battery440so that the physiological sensor400can still operate in dark conditions. The solar cell415can be included, for example, in addition to, or in place of, the electrochemical fuel cell410. As discussed above, the foregoing embodiments may be used in the diagnosis or treatment of glaucoma. About two percent of people in the United States have glaucoma. Glaucoma is a group of eye diseases that causes pathological changes in the optic disk and corresponding visual field loss, resulting in blindness if untreated. Intraocular pressure elevation is a major etiologic factor in glaucoma. In certain embodiments, a sensor implant, such as those described herein, may be used and/or delivered together with one or more implants that provide for drug delivery to the eye and/or drainage of aqueous humor from the anterior chamber as a treatment for glaucoma. In glaucomas associated with an elevation in intraocular pressure (“IOP”), the source of resistance to outflow of aqueous humor is mainly in the trabecular meshwork. The tissue of the trabecular meshwork allows the aqueous humor, or aqueous, to enter Schlemm's canal, which then empties into aqueous collector channels in the posterior wall of Schlemm's canal and then into aqueous veins, which form the episcleral venous system. Aqueous humor is a transparent liquid that fills the region between the cornea, at the front of the eye, and the lens. The aqueous humor is continuously secreted by the ciliary body around the lens, so there is an essentially constant flow of aqueous humor from the ciliary body to the eye's anterior chamber. The anterior chamber pressure is determined by a balance between the production of aqueous and its exit through the trabecular meshwork (major route) or uveoscleral outflow (minor route). The trabecular meshwork is located between the outer rim of the iris and the back of the cornea, in the anterior chamber angle. The portion of the trabecular meshwork adjacent to Schlemm's canal (the juxtacanilicular meshwork) causes most of the resistance to aqueous outflow. Two primary methods of alleviating the imbalance between the production and drainage of aqueous humor are use of pharmaceuticals that reduce IOP and use of ocular implants that enhance drainage of aqueous from the anterior chamber. Implants may provide a route to allow drainage of aqueous from the anterior chamber. The implant may be designed to allow drainage to any suitable location, including the subconjunctival space (including use of a bleb) and a physiologic outflow path such as Schlemm's canal or the uveoscleral outflow pathway (including suprachoroidal space and/or supraciliary space). Any of a wide variety of ocular implants to enhance aqueous drainage may be used in connection with other implants as disclosed herein. For example, U.S. Pat. Nos. 6,638,239 and 6,736,791 disclose devices and methods of placing a drainage device or shunt ab interno. The stent includes a hollow, elongate tubular element, having an inlet section and an outlet section. The outlet section may optionally include two segments or elements, adapted to be positioned and stabilized inside Schlemm's canal. In one embodiment, the device appears as a “T” shaped device. In another embodiment, the device appears as a “L” shaped device. In still another embodiment, the device appears as a “I” shaped embodiment. The entire contents of each one of these patents are hereby incorporated by reference herein. Other implants are suitable for use in providing aqueous drainage. For example, one embodiment of a drainage implant has a longitudinal axis and comprises a first portion sized and configured to reside at least partially in the anterior chamber and a second portion sized and configured to reside within Schlemm's canal, the suprachoroidal space, or another physiological outflow pathway of the major or minor route. The first portion also includes an inlet section that communicates with a lumen that runs along the longitudinal implant axis and communicates with one or more exit or outflow ports in the second portion of the device. Another type of device may be in a form that resembles a rivet, wherein there is an inlet portion that resides in the anterior chamber, a distal portion having one or more outlets and is adapted to reside in a physiologic outflow pathway (e.g. Schlemm's canal, uveoscleral outflow pathway, suprachoroidal space, supraciliary space), and an intermediate portion adapted to extend through tissue and provide fluid communication between the inlet and distal portions. The devices may also comprise one or more retention features (e.g. ridges, barbs, protrusions, etc.) to assist in retaining the device in the desired location in the eye. Such devices may also include one or more drugs. These and other suitable implants are disclosed in U.S. Pat. Nos. 7,135,009, 7,857,782, 7,431,710, and 7,879,001, the disclosures of which are hereby incorporated by reference in their entireties. Any of the foregoing implants may feature a drug coating in addition to providing drainage, wherein the drug may be any type as disclosed herein, including drugs to treat glaucoma or other eye conditions, and drugs to prevent or reduce scarring, fibrosis, clotting and other deleterious effects that may result from implantation of a device. In other embodiments, the devices may be adapted to deliver one or more drugs over a desired period of time by providing the drug in bulk form, e.g. placed in a recess or lumen in the device, or in the form of a tablet or mass that is affixed to or contained within the body of the device. Bulk drug may also take the form of a tiny pellet or tablet which may be placed in a recess or lumen of a device or affixed to the device. Where the drug is present in bulk form, the device may also include a drainage lumen. In some embodiments, the drainage lumen also includes drug so that drainage of aqueous facilitates drug elution. Devices may also include both bulk drug and a drug coating. Examples of such devices are found in International Patent Application Publication No. WO 2010/135369, the disclosure of which is hereby incorporated by reference in its entirety. FIG.5Ais a schematic illustration of an implantable intraocular physiological sensor500that also enhances drainage of the aqueous humor to help treat glaucoma. The physiological sensor500includes a physiological characteristic sensing module560, which could be, for example, electromechanical (such as a capacitive intraocular pressure sensor), electrochemical (such as an amperometric glucose sensor), or optical (such as a fluorescent glucose sensor). The physiological sensor500also includes electrochemical fuel cells510and various electronic components, such as those described herein. The implantable device can also incorporate onboard memory, logical control (such as microprocessor), software, firmware, digitization, and wireless (radiofrequency or optical) communication. For example, the sensor500can include a controller module570, a signal conditioning and analog-to-digital conversion module574, a transmitter, etc. The transmitter can include an antenna580. Some or all of these components can be provided on, or attached to, a carrier member572. In some embodiments, the carrier member572is a circuit board. As discussed further herein, the sensor device500may be designed so as to be implantable at or in various anatomical features of the eye. Accordingly, in some embodiments, the carrier member572is flexible so as to allow it to satisfactorily conform to a desired anatomical feature. The flexible carrier member572can be, for example, a bendable film, such as Kapton™ (polyimide), or comprise a flexible electrical circuit, known as a “flex circuit.”FIG.5Bis a schematic illustration of an embodiment of the carrier member572. As illustrated, the carrier member572can be made from a flexible material that allows the carrier member572to be deformed into a curvilinear form. Various modules590can be mounted on the carrier member572at spaced apart intervals on both sides of the carrier member. The modules590can also be stacked. The illustrated modules590can represent, for example, any of the modules discussed herein (e.g., controller, transmitter, etc.). Signal connection lines such as electrical traces can be formed on the carrier member572between the various modules590. Since the modules590are mounted on the carrier member572at spaced apart intervals, the combination of the carrier member572and the modules590can more freely the form to take the shape of the anatomy where it may be implanted. Although not illustrated, the fuel cells510and the carrier member572, as well as its mounted electronic components, are provided within a fluid channel. The fluid channel can be, for example, a lumen or sheath that is generally cylindrical in shape, though other shapes are possible as well. In some embodiments, the lumen or sheath may have a generally circular, square, or rectangular cross-sectional shape. Square and rectangular cross-sectional shapes may be advantageous in terms of more efficiently being able to fit circuit boards, electronics, etc. within the sheath. Although the sheath may have a generally square or rectangular cross-sectional shape, the corners of the square or rectangular may be rounded in order to ease insertion of the device into, for example, Schlemm's canal or the suprachoroidal space and avoid any damage to the tissue. The fluid channel can have an inlet port that is designed to be in fluid communication with the aqueous humor in the eye when the sensor device is implanted at the intended surgical location. The fluid channel can also have a fluid outlet port that is designed to be in communication with a physiological outflow pathway of the aqueous humor. For example, the outlet port of the fluid channel could be located in the suprachoroidal space or in Schlemm's canal. As the aqueous humor flows through the fluid channel, it can come into contact with the fuel cells510, thus providing fuel (e.g., glucose dissolved in the aqueous humor) to the fuel cells for the generation of electrical power to operate the sensor device500. In addition, the sensor device500may include a pumping module (not shown) to assist the flow of aqueous through the fluid channel. In some embodiments, the physiological characteristic sensing module560is designed to measure intraocular pressure. Accordingly, in such embodiments, the sensing module560may be designed to be located in the anterior chamber of the eye when the device500is implanted at the intended destination in the eye. However, as discussed herein, the sensing module560may also, or alternatively, be designed to measure other physiological characteristics. As illustrated inFIG.5A, the sensing module560may be a modular component that is detachable from the remainder of the device500. In the particular illustrated embodiment, the sensing module560includes a notched connector566that mates with the carrier member572, which is illustrated as a circuit board. The circuit board also includes electrical lines for communicating signals and power to/from the sensing module560. The sensing module560may also include a connector564that mates with the fluid channel, which encloses the carrier member572, electronic components (e.g.,570,574,580) and the fuel cells510. In particular, the sensing module560may be a cap that mounts in one open and of a sheath that serves as the fluid channel. A fluid inlet port562can be provided in the sensing module560to allow the fluid channel to be in fluid communication with the aqueous humor that surrounds the sensing module. As discussed herein, the fuel cells510can be glucose fuel cells. While two separate fuel cells are illustrated inFIG.5A, other embodiments may use only one, or some other number, of fuel cells. Glucose-containing aqueous humor can enter the inlet port562of the sensing module560. The aqueous humor can then flow through the fluid channel that is capped by the sensing module, over and around the carrier member572and electrical components (e.g., controller module570, signal conditioning module574, antenna580), and then over and around the fuel cells510before exiting an outlet port of the fluid channel into a physiological outflow pathway of the aqueous humor. Based on initial estimates, the glucose fuel cells510may be capable of providing approximately 1.5 mW/cm2of surface area. The size and surface area of the fuel cells510may vary from application to application depending upon available space. However, an initial estimate for an application where the sensor device500is sized to be insertable into the suprachoroidal space is that each of the fuel cells may have a surface area of about 2.9×10−3cm2. Based on these estimates, each of the fuel cells510may produce about 4.3×10−3mW. Thus, the combination of the two fuel cells would provide approximately 8 μW. According to initial estimates, the glucose fuel cells510would require approximately 4.8×10−8moles of glucose per minute in order to generate the 8 μW of power. Based on typical aqueous humor production rates and glucose concentrations in the aqueous, the glucose required by the fuel cells may be a small percentage of the available glucose in the eye (e.g., 0.4%). In some embodiments, the sensor device500is estimated to consume on the order of the few microwatts while performing a measurement and a few picowatts while in a standby low-power mode between measurements. Transmission of the measurements to an external device may require more power, however; perhaps on the order of milliwatts for a short period of time. The precise power demands of the sensor device500will depend on numerous factors, including the frequency of measurements, the frequency and required range of data transmission to an external device, etc. However, additional, or fewer, fuel cells can be used depending upon the power requirements of the sensor device500. FIG.6is a schematic illustration showing the device500ofFIG.5Aimplanted in the eye600. In particular,FIG.6is a superior view of the placement of the sensor device500, which also shows transmission of electromagnetic waves from the antenna580.FIG.6shows the eye600, with the anterior chamber610, the optic nerve616, and various other anatomical features. The cheekbone620is also shown. In some embodiments, the sensor device500is designed to be implanted and/or anchored at least partially in the suprachoroidal space of the eye, as illustrated. In such embodiments, the sensor device500may be designed with a generally elongate, cylindrical shape having an outer diameter or dimension of about 0.6 mm or less. In some embodiments, the generally elongate, cylindrical sensor device500measures about 3-14 mm in length. In some embodiments, the generally elongate, cylindrical sensor device500is about 4 mm in length, has an outer diameter or dimension of about 360 μm and inner diameter or dimension of about 160 μm. The body of the sensor device500can be made of various materials, including polyethersulfone (PES). In addition, in some embodiments, the sensor device can be inserted into the anterior chamber via a self-sealing incision at or near the limbus, although it could also be inserted through other openings such as the incision made for cataract surgery, trabeculectomy or other ophthalmic surgical procedures. As already discussed, the sensor device500may be inserted such that the sensing module560remains in the anterior chamber610and in fluid communication with the aqueous humor, while the remaining portion of the device500is at least partially located in the suprachoroidal space and/or other portion of the uveoscleral outflow pathway. This placement allows the sensing module560to measure intraocular pressure within the anterior chamber610, while also providing for aqueous drainage through the fluid channel to the suprachoroidal space. In some embodiments, certain components of the sensor device500, including but not limited to a pressure sensor module and solar cell, could be designed to be insertable into the anterior chamber through a tiny incision as part of a device which would anchor in the suprachoroidal space and subsequently unfurl or enlarge once in position or during positioning. In embodiments with this unfurling or enlarging action, rigid componentry could be mounted to a flexible backer. Other intraocular placements for the sensor device500may also be used. For example, the sensor device500may be designed to be at least partially inserted into Schlemm's canal. In such embodiments, the sensor device500may have, for example, a generally elongate, cylindrical shape with a diameter or dimension of about 150 μm or less. As already discussed, in some embodiments (such as intraocular pressure sensors), the sensor device500may be implanted completely within the suprachoroidal space of the eye. The sensor device500may be configured for placement in the supraciliary or suprachoroidal space by making it elongated in one dimension, and narrow or thin in a second and/or third dimension. The elongated dimension may be in the range of 2-25 mm, or more specifically 3-14 mm, while the narrow dimension(s) may be less than 1 mm, and preferably less than 0.6 mm in order to (a) facilitate insertion into the eye through a small gauge insertion needle or cannula; and/or (b) make the device flexible enough to conform to curvature of the anatomy (for example, the curvature of the sclera). At least one possible advantage of the placement illustrated inFIG.6is that the antenna580may be largely unobscured by bone, such as the orbital bone or cheekbone620. Thus, the antenna580may only be required to transmit through soft tissue. This can ease the power demands of the transmitter and/or increase the transmission range of the device. Another advantage of placement of the sensor device500in the anterior chamber is that this body location is immunologically privileged, as discussed herein. In other body locations, collagen (“fibrous”) encapsulation may occur as a reaction to the presence of a foreign body. Fibrous encapsulation is an obstacle that may reduce the useful life of implanted biomedical sensors. The anterior chamber, in contrast, is one of a very few sites in the body demonstrating “immune privilege” such that a foreign body may be introduced without eliciting an inflammatory immune response. Therefore, a foreign body such as a glucose (or other) biosensor, implanted with minimum trauma and located at least in part within the anterior chamber, may well experience less fibrous encapsulation and a longer useful life than the same biosensor implanted elsewhere in the body. As discussed herein, the sensor device500can be used as part of a system whereby intraocular pressure values measured and temporarily stored by the implanted sensor are read automatically by a monitor, such as a device at a patient's bedside that interrogates the implanted sensor during sleep. In some embodiments, the bedside monitor would interface to, for example, the internet, and automatically send data to a doctor's office for evaluation. This system could include time stamping and temporary storage in memory of intraocular pressure measurements made by the implanted sensor. The sensor measurements could be continuous or intermittent, and the device could be switchable, between active and quiescent states. FIG.7is a schematic illustration of an implantable intraocular physiological sensor700with an anchoring member702. The anchoring member702can be used to fixedly attach the sensor700to eye tissue704, such as eye tissue comprising a physiological outflow pathway for aqueous humor. The anchoring member702is illustrated with barbed retention features, but it can include any of many different types of retention features. In addition, the physiological sensors700can include any of the features discussed herein with respect to any other sensor device. FIG.8is a schematic illustration of an implantable intraocular physiological sensor800with an anchoring member802and a fluid channel. Thus, the physiological sensor800advantageously combines aqueous drainage features with physiological characteristic sensing features. The sensor800includes a head portion805in which a sensing module, a controller module, a transmitter, a fuel cell, etc. can be included, as discussed herein. The head portion805can be attached to the anchoring member802by a stem portion803. In some embodiments, the anchoring member802is a tapered bulbous portion that allows penetration into the eye tissue804, and retention in such eye tissue. In some embodiments, the length of the stem portion803corresponds to the thickness of the eye tissue804where the sensor device800is designed to be located. The sensor device800can also include a fluid channel808, which is illustrated by dotted lines to indicate that it is an interior feature. In some embodiments, the fluid channel808has an inlet port at the head portion805of the sensor device800. The fluid channel808can extend from the head portion, which is designed to be in fluid communication with the aqueous humor when the sensor device800is implanted, through the stem portion803, to the anchoring member802. In some embodiments, the sensor device800may include external fluid channels and outlet features, such as grooves. The anchoring member802can include one or more fluid outlet ports806. In some embodiments, the physiological sensor800is sized and shaped to be inserted into the anterior chamber of the eye and anchored into eye tissue804. In one embodiment, the implant is anchored to the trabecular meshwork, thus allowing enhanced drainage of the aqueous humor into Schlemm's canal. FIG.9is a schematic illustration of an implantable intraocular physiological sensor900with an anchoring member902and a fluid channel908that does not pass through an electronics housing portion of the physiological sensor. The physiological sensor900includes a head portion905, which in this embodiment, serves as a housing for various electronic components of the sensor (e.g., sensing module, controller module, transmitter, fuel cell, etc.). The head portion905is connected to an anchoring member902via a stem portion903. The stem portion903includes one or more fluid inlet ports909and a fluid channel908. The fluid channel908extends into the anchoring member902, which includes one or more fluid outlet ports906. The stem portion903also includes a flange907along its length between the head portion905and the anchoring member902. The flange907, in conjunction with the anchoring member902, allows the sensor device900to be mounted to eye tissue904such that the head portion905is raised above the tissue904. The inlet ports909of the fluid channel908are located in the stem portion903between the head portion905and the flange907. Accordingly, the fluid channel908need not necessarily pass through the housing (e.g., head portion905) where electronic components are located. This can be advantageous because locating the fluid channel through the electronics housing may complicate layout of the electronic components within the housing. In the embodiment illustrated inFIG.9, however, the electronics housing and the fluid channel can be designed substantially independently. The illustrations inFIGS.7-10are schematic in nature. Accordingly, the shape, location, and design of the implants and features of the implants may be different from what is illustrated. For example, the shape and relative sizes of features including but not limited to the head portion, anchoring portion, and flanges can be as illustrated or they may have different shapes. In other embodiments, the cross-sectional shape of the head portion may be circular or polygonal, and the top may be generally flat or curved and it may be larger or smaller in size as compared to the other features of the implant. In other embodiments, an anchor, anchoring portion and/or flange(s) may be of different sizes and shapes, including those disclosed in U.S. Pat. No. 7,857,782, which is hereby incorporated by reference in its entirety. Implants may have more or fewer inlet and/or outlet ports, the inlet and/or outlet ports may be different sizes and/or shapes and at different locations than those illustrated. As stated previously, the sensor device may be configured for placement in the supraciliary or suprachoroidal space by making it elongated in one dimension, and narrow or thin in a second and/or third dimension. The elongated dimension may be in the range of 2-25 mm, while the narrow dimension(s) may be less than 1 mm, and preferably less than 0.5 mm in order to (a) facilitate insertion into the eye through a small gauge insertion needle or cannula; and/or (b) make the device flexible enough to conform to curvature of the anatomy (for example, the curvature of the sclera). Implants as described herein may include one or more drugs to be delivered to the eye. Devices having drug delivery capabilities allow for a drug to be delivered directly to the eye, and may also allow for targeted delivery to a structure within the eye, such as, for example, the macula, the retina, the ciliary body, the optic nerve, or the vascular supply to certain regions of the eye. Use of a drug eluting implant could also provide the opportunity to administer a controlled amount of drug for a desired amount of time, depending on the pathology. For instance, some pathologies may require drugs to be released at a constant rate for just a few days, others may require drug release at a constant rate for up to several months, still others may need periodic or varied release rates over time, and even others may require periods of no release. Further, implants may serve additional functions once the delivery of the drug is complete. Implants may maintain the patency of a fluid flow passageway within an ocular cavity, they may function as a reservoir for future administration of the same or a different therapeutic agent, or may also function to maintain the patency of a fluid flow pathway or passageway from a first location to a second location, e.g. function as a stent. Conversely, should a drug be required only acutely, an implant may also be made completely biodegradable. As used herein, “drug” refers generally to one or more drugs that may be administered alone, in combination and/or compounded with one or more pharmaceutically acceptable excipients (e.g. binders, disintegrants, fillers, diluents, lubricants, drug release control polymers or other agents, etc.), auxiliary agents or compounds as may be housed within the implants as described herein. The term “drug” is a broad term that may be used interchangeably with terms such as “therapeutic agent” and “pharmaceutical” or “pharmacological agent” and includes not only so-called small molecule drugs, but also macromolecular drugs, and biologics, including but not limited to proteins, nucleic acids, antibodies and the like, regardless of whether such drug is natural, synthetic, or recombinant. “Drug” may refer to the drug alone or in combination with the excipients described above. “Drug” may also refer to an active drug itself or a prodrug or salt of an active drug. Following implantation at the desired site within the eye, drug is released from the implant in a targeted and controlled fashion, based on the design of the various aspects of the implant, preferably for an extended period of time. The implant and associated methods disclosed herein may be used in the treatment of pathologies requiring drug administration to the posterior chamber of the eye, the anterior chamber of the eye, or to specific tissues within the eye. In some embodiments functioning as a drug delivery device alone, the implant is configured to deliver one or more drugs to anterior region of the eye in a controlled fashion while in other embodiments the implant is configured to deliver one or more drugs to the posterior region of the eye in a controlled fashion. In still other embodiments, the implant is configured to simultaneously deliver drugs to both the anterior and posterior region of the eye in a controlled fashion. In yet other embodiments, the configuration of the implant is such that drug is released in a targeted fashion to a particular intraocular tissue, for example, the macula, ciliary body, ciliary processes, ciliary muscles, Schlemm's canal, trabecular meshwork, episcleral veins, lens cortex, lens epithelium, lens capsule, choroid, optic nerve, and/or retina. In certain embodiments the drug delivery implant may contain one or more drugs which may or may not be compounded with a bioerodible polymer or a bioerodible polymer and at least one additional agent. In still other embodiments, the drug delivery implant is used to sequentially deliver multiple drugs. Additionally, certain embodiments are constructed using different outer shell materials, and/or materials of varied permeability to generate a tailored drug elution profile. Certain embodiments are constructed using different numbers, dimensions and/or locations of orifices in the implant shell to generate a tailored drug elution profile. Certain embodiments are constructed using different polymer coatings and different coating locations on the implant to generate a tailored drug elution profile. Embodiments may elute drug at a constant rate, with a zero-order release profile, or variable elution profile. Some embodiments are designed to stop elution completely or nearly completely for a predetermined period of time (e.g., a “drug holiday”) and later resume elution at the same or a different elution rate or concentration. Some such embodiments elute the same therapeutic agent before and after the drug holiday while other embodiments elute different therapeutic agents before and after the drug holiday. The therapeutic agents utilized with embodiments having drug delivery capabilities, including separate drug delivery implants used in conjunction with a sensor, as well as any implant having a coating comprising a drug may include one or more drugs provided below, either alone or in combination. The drugs utilized may also be the equivalent of, derivatives of, or analogs of one or more of the drugs provided below. The drugs may include but are not limited to pharmaceutical agents including anti-glaucoma medications, ocular agents, antimicrobial agents (e.g., antibiotic, antiviral, antiparasitic, antifungal agents), anti-inflammatory agents (including steroids or non-steroidal anti-inflammatory), biological agents including hormones, enzymes or enzyme-related components, antibodies or antibody-related components, oligonucleotides (including DNA, RNA, short-interfering RNA, antisense oligonucleotides, and the like), DNA/RNA vectors, viruses (either wild type or genetically modified) or viral vectors, peptides, proteins, enzymes, extracellular matrix components, and live cells configured to produce one or more biological components. The use of any particular drug is not limited to its primary effect or regulatory body-approved treatment indication or manner of use. Drugs also include compounds or other materials that reduce or treat one or more side effects of another drug or therapeutic agent. As many drugs have more than a single mode of action, the listing of any particular drug within any one therapeutic class below is only representative of one possible use of the drug and is not intended to limit the scope of its use with the ophthalmic implant system. As discussed above, the therapeutic agents may be combined with any number of excipients as is known in the art. In addition to the biodegradable polymeric excipients discussed above, other excipients may be used, including, but not limited to, benzyl alcohol, ethylcellulose, methylcellulose, hydroxymethylcellulose, cetyl alcohol, croscarmellose sodium, dextrans, dextrose, fructose, gelatin, glycerin, monoglycerides, diglycerides, kaolin, calcium chloride, lactose, lactose monohydrate, maltodextrins, polysorbates, pregelatinized starch, calcium stearate, magnesium stearate, silicon dioxide, cornstarch, talc, and the like. The one or more excipients may be included in total amounts as low as about 1%, 5%, or 10% and in other embodiments may be included in total amounts as high as 50%, 70%, 90% or more. High amounts of excipient are desirable when the drug is in the form of a microscopic pellet or tablet. Additional disclosure on such tablets may be found in International Patent Application Publication No. WO 2010/135369, the disclosure of which is hereby incorporated by reference in its entirety. Examples of drugs may include various anti-secretory agents; antimitotics and other anti-proliferative agents, including among others, anti-angiogenesis agents such as angiostatin, anecortave acetate, thrombospondin, VEGF receptor tyrosine kinase inhibitors and anti-vascular endothelial growth factor (anti-VEGF) drugs such as ranibizumab (LUCENTIS®) and bevacizumab (AVASTIN®), pegaptanib (MACUGEN®), sunitinib and sorafenib and any of a variety of small-molecule and transcription inhibitors having anti-angiogenesis effect; classes of known ophthalmic drugs, including: glaucoma agents, such as adrenergic antagonists, including for example, beta-blocker agents such as atenolol propranolol, metipranolol, betaxolol, carteolol, levobetaxolol, levobunolol and timolol; adrenergic agonists or sympathomimetic agents such as epinephrine, dipivefrin, clonidine, aparclonidine, and brimonidine; parasympathomimetics or cholingeric agonists such as pilocarpine, carbachol, phospholine iodine, and physostigmine, salicylate, acetylcholine chloride, eserine, diisopropyl fluorophosphate, demecarium bromide); muscarinics; carbonic anhydrase inhibitor agents, including topical and/or systemic agents, for example acetozolamide, brinzolamide, dorzolamide and methazolamide, ethoxzolamide, diamox, and dichlorphenamide; mydriatic-cycloplegic agents such as atropine, cyclopentolate, succinylcholine, homatropine, phenylephrine, scopolamine and tropicamide; prostaglandins such as prostaglandin F2 alpha, antiprostaglandins, prostaglandin precursors, or prostaglandin analog agents such as bimatoprost, latanoprost, travoprost and unoprostone. Other examples of drugs may also include anti-inflammatory agents including for example glucocorticoids and corticosteroids such as betamethasone, cortisone, dexamethasone, dexamethasone 21-phosphate, methylprednisolone, prednisolone 21-phosphate, prednisolone acetate, prednisolone, fluroometholone, loteprednol, medrysone, fluocinolone acetonide, triamcinolone acetonide, triamcinolone, triamcinolone acetonide, beclomethasone, budesonide, flunisolide, fluorometholone, fluticasone, hydrocortisone, hydrocortisone acetate, loteprednol, rimexolone and non-steroidal anti-inflammatory agents including, for example, diclofenac, flurbiprofen, ibuprofen, bromfenac, nepafenac, and ketorolac, salicylate, indomethacin, ibuprofen, naxopren, piroxicam and nabumetone; anti-infective or antimicrobial agents such as antibiotics including, for example, tetracycline, chlortetracycline, bacitracin, neomycin, polymyxin, gramicidin, cephalexin, oxytetracycline, chloramphenicol, rifampicin, ciprofloxacin, tobramycin, gentamycin, erythromycin, penicillin, sulfonamides, sulfadiazine, sulfacetamide, sulfamethizole, sulfisoxazole, nitrofurazone, sodium propionate, aminoglycosides such as gentamicin and tobramycin; fluoroquinolones such as ciprofloxacin, gatifloxacin, levofloxacin, moxifloxacin, norfloxacin, ofloxacin; bacitracin, erythromycin, fusidic acid, neomycin, polymyxin B, gramicidin, trimethoprim and sulfacetamide; antifungals such as amphotericin B and miconazole; antivirals such as idoxuridine trifluorothymidine, acyclovir, gancyclovir, interferon; antimicotics; immune-modulating agents such as antiallergenics, including, for example, sodium chromoglycate, antazoline, methapyriline, chlorpheniramine, cetrizine, pyrilamine, prophenpyridamine; anti-histamine agents such as azelastine, emedastine and levocabastine; immunological drugs (such as vaccines and immune stimulants); MAST cell stabilizer agents such as cromolyn sodium, ketotifen, lodoxamide, nedocrimil, olopatadine and pemirolastciliary body ablative agents, such as gentimicin and cidofovir; and other ophthalmic agents such as verteporfin, proparacaine, tetracaine, cyclosporine and pilocarpine; inhibitors of cell-surface glycoprotein receptors; decongestants such as phenylephrine, naphazoline, tetrahydrazoline; lipids or hypotensive lipids; dopaminergic agonists and/or antagonists such as quinpirole, fenoldopam, and ibopamine; vasospasm inhibitors; vasodilators; antihypertensive agents; angiotensin converting enzyme (ACE) inhibitors; angiotensin-1 receptor antagonists such as olmesartan; microtubule inhibitors; molecular motor (dynein and/or kinesin) inhibitors; actin cytoskeleton regulatory agents such as cyctchalasin, latrunculin, swinholide A, ethacrynic acid, H-7, and Rho-kinase (ROCK) inhibitors; remodeling inhibitors; modulators of the extracellular matrix such as tert-butylhydro-quinolone and AL-3037A; adenosine receptor agonists and/or antagonists such as N-6-cylclophexyladenosine and (R)-phenylisopropyladenosine; serotonin agonists; hormonal agents such as estrogens, estradiol, progestational hormones, progesterone, insulin, calcitonin, parathyroid hormone, peptide and vasopressin hypothalamus releasing factor; growth factor antagonists or growth factors, including, for example, epidermal growth factor, fibroblast growth factor, platelet derived growth factor or antagonists thereof (such as those disclosed in U.S. Pat. No. 7,759,472 or U.S. patent application Ser. No. 12/465,051, 12/564,863, or 12/641,270, each of which is incorporated in its entirety by reference herein), transforming growth factor beta, somatotrapin, fibronectin, connective tissue growth factor, bone morphogenic proteins (BMPs); cytokines such as interleukins, CD44, cochlin, and serum amyloids, such as serum amyloid A. Other therapeutic agents may include neuroprotective agents such as lubezole, nimodipine and related compounds, and including blood flow enhancers such as dorzolamide or betaxolol; compounds that promote blood oxygenation such as erythropoeitin; sodium channels blockers; calcium channel blockers such as nilvadipine or lomerizine; glutamate inhibitors such as memantine nitromemantine, riluzole, dextromethorphan or agmatine; acetylcholinsterase inhibitors such as galantamine; hydroxylamines or derivatives thereof, such as the water soluble hydroxylamine derivative OT-440; synaptic modulators such as hydrogen sulfide compounds containing flavonoid glycosides and/or terpenoids, such asGinkgo biloba; neurotrophic factors such as glial cell-line derived neutrophic factor, brain derived neurotrophic factor; cytokines of the IL-6 family of proteins such as ciliary neurotrophic factor or leukemia inhibitory factor; compounds or factors that affect nitric oxide levels, such as nitric oxide, nitroglycerin, or nitric oxide synthase inhibitors; cannabinoid receptor agonsists such as WIN55-212-2; free radical scavengers such as methoxypolyethylene glycol thioester (MPDTE) or methoxypolyethlene glycol thiol coupled with EDTA methyl triester (MPSEDE); anti-oxidants such as astaxathin, dithiolethione, vitamin E, or metallocorroles (e.g., iron, manganese or gallium corroles); compounds or factors involved in oxygen homeostasis such as neuroglobin or cytoglobin; inhibitors or factors that impact mitochondrial division or fission, such as Mdivi-1 (a selective inhibitor of dynamin related protein 1 (Drp1)); kinase inhibitors or modulators such as the Rho-kinase inhibitor H-1152 or the tyrosine kinase inhibitor AG1478; compounds or factors that affect integrin function, such as the Beta 1-integrin activating antibody HUTS-21; N-acyl-ethanaolamines and their precursors, N-acyl-ethanolamine phospholipids; stimulators of glucagon-like peptide 1 receptors (e.g., glucagon-like peptide 1); polyphenol containing compounds such as resveratrol; chelating compounds; apoptosis-related protease inhibitors; compounds that reduce new protein synthesis; radiotherapeutic agents; photodynamic therapy agents; gene therapy agents; genetic modulators; auto-immune modulators that prevent damage to nerves or portions of nerves (e.g., demyelination) such as glatimir; myelin inhibitors such as anti-NgR Blocking Protein, NgR(310)ecto-Fc; other immune modulators such as FK506 binding proteins (e.g., FKBP51); and dry eye medications such as cyclosporine A, delmulcents, and sodium hyaluronate. Other therapeutic agents that may be used include: other beta-blocker agents such as acebutolol, atenolol, bisoprolol, carvedilol, asmolol, labetalol, nadolol, penbutolol, and pindolol; other corticosteroidal and non-steroidal anti-inflammatory agents such aspirin, betamethasone, cortisone, diflunisal, etodolac, fenoprofen, fludrocortisone, flurbiprofen, hydrocortisone, ibuprofen, indomethacine, ketoprofen, meclofenamate, mefenamic acid, meloxicam, methylprednisolone, nabumetone, naproxen, oxaprozin, prednisolone, prioxicam, salsalate, sulindac and tolmetin; COX-2 inhibitors like celecoxib, rofecoxib and. Valdecoxib; other immune-modulating agents such as aldesleukin, adalimumab (HUMIRA®), azathioprine, basiliximab, daclizumab, etanercept (ENBREL®), hydroxychloroquine, infliximab (REMICADE®), leflunomide, methotrexate, mycophenolate mofetil, and sulfasalazine; other anti-histamine agents such as loratadine, desloratadine, cetirizine, diphenhydramine, chlorpheniramine, dexchlorpheniramine, clemastine, cyproheptadine, fexofenadine, hydroxyzine and promethazine; other anti-infective agents such as aminoglycosides such as amikacin and streptomycin; anti-fungal agents such as amphotericin B, caspofungin, clotrimazole, fluconazole, itraconazole, ketoconazole, voriconazole, terbinafine and nystatin; anti-malarial agents such as chloroquine, atovaquone, mefloquine, primaquine, quinidine and quinine; anti-mycobacteriumagents such as ethambutol, isoniazid, pyrazinamide, rifampin and rifabutin; anti-parasitic agents such as albendazole, mebendazole, thiobendazole, metronidazole, pyrantel, atovaquone, iodoquinaol, ivermectin, paromycin, praziquantel, and trimatrexate; other anti-viral agents, including anti-CMV or anti-herpetic agents such as acyclovir, cidofovir, famciclovir, gangciclovir, valacyclovir, valganciclovir, vidarabine, trifluridine and foscarnet; protease inhibitors such as ritonavir, saquinavir, lopinavir, indinavir, atazanavir, amprenavir and nelfinavir; nucleotide/nucleoside/non-nucleoside reverse transcriptase inhibitors such as abacavir, ddI, 3TC, d4T, ddC, tenofovir and emtricitabine, delavirdine, efavirenz and nevirapine; other anti-viral agents such as interferons, ribavirin and trifluridiene; other anti-bacterial agents, including cabapenems like ertapenem, imipenem and meropenem; cephalosporins such as cefadroxil, cefazolin, cefdinir, cefditoren, cephalexin, cefaclor, cefepime, cefoperazone, cefotaxime, cefotetan, cefoxitin, cefpodoxime, cefprozil, ceftaxidime, ceftibuten, ceftizoxime, ceftriaxone, cefuroxime and loracarbef; other macrolides and ketolides such as azithromycin, clarithromycin, dirithromycin and telithromycin; penicillins (with and without clavulanate) including amoxicillin, ampicillin, pivampicillin, dicloxacillin, nafcillin, oxacillin, piperacillin, and ticarcillin; tetracyclines such as doxycycline, minocycline and tetracycline; other anti-bacterials such as aztreonam, chloramphenicol, clindamycin, linezolid, nitrofurantoin and vancomycin; alpha blocker agents such as doxazosin, prazosin and terazosin; calcium-channel blockers such as amlodipine, bepridil, diltiazem, felodipine, isradipine, nicardipine, nifedipine, nisoldipine and verapamil; other anti-hypertensive agents such as clonidine, diazoxide, fenoldopan, hydralazine, minoxidil, nitroprus side, phenoxybenzamine, epoprostenol, tolazoline, treprostinil and nitrate-based agents; anti-coagulant agents, including heparins and heparinoids such as heparin, dalteparin, enoxaparin, tinzaparin and fondaparinux; other anti-coagulant agents such as hirudin, aprotinin, argatroban, bivalirudin, desirudin, lepirudin, warfarin and ximelagatran; anti-platelet agents such as abciximab, clopidogrel, dipyridamole, optifibatide, ticlopidine and tirofiban; prostaglandin PDE-5 inhibitors and other prostaglandin agents such as alprostadil, carboprost, sildenafil, tadalafil and vardenafil; thrombin inhibitors; antithrombogenic agents; anti-platelet aggregating agents; thrombolytic agents and/or fibrinolytic agents such as alteplase, anistreplase, reteplase, streptokinase, tenecteplase and urokinase; anti-proliferative agents such as sirolimus, tacrolimus, everolimus, zotarolimus, paclitaxel and mycophenolic acid; hormonal-related agents including levothyroxine, fluoxymestrone, methyltestosterone, nandrolone, oxandrolone, testosterone, estradiol, estrone, estropipate, clomiphene, gonadotropins, hydroxyprogesterone, levonorgestrel, medroxyprogesterone, megestrol, mifepristone, norethindrone, oxytocin, progesterone, raloxifene and tamoxifen; anti-neoplastic agents, including alkylating agents such as carmustine lomustine, melphalan, cisplatin, fluorouracil3, and procarbazine antibiotic-like agents such as bleomycin, daunorubicin, doxorubicin, idarubicin, mitomycin and plicamycin; anti proliferative agents (such as 1,3-cis retinoic acid, 5-fluorouracil, taxol, rapamycin, mitomycin C and cisplatin); antimetabolite agents such as cytarabine, fludarabine, hydroxyurea, mercaptopurine and 5-fluorouracil (5-FU); immune modulating agents such as aldesleukin, imatinib, rituximab and tositumomab; mitotic inhibitors docetaxel, etoposide, vinblastine and vincristine; radioactive agents such as strontium-89; and other anti-neoplastic agents such as irinotecan, topotecan and mitotane. FIG.10is a schematic illustration of an implantable intraocular physiological sensor1000with an anchoring member1002and a drug repository or drug delivery device1001. The physiological sensor1000can include a head portion1005, which may house various components described herein, such as a sensing module, a controller module, a transmitter, a fuel cell, etc. The head portion1005is attached to the anchoring member1002by a stem portion1003. The anchoring member1002can be used to mount to the device1000in eye tissue, as described herein. The physiological sensor1000also includes a drug repository1001. Although the drug repository or drug delivery device1001is illustrated as an opening in the head portion1005of the sensor1000, it can be located at various positions on the device1000. The drug repository or drug delivery device1001can be provided with any of the drugs described herein. In some embodiments, the drug repository or drug delivery device1001can either continuously release a drug or release controlled amounts of a drug upon command. In some embodiments, the physiological sensors described herein can be used to provide a closed monitoring and control system for treating a physiological condition. For example, a target value for a physiological characteristic can be stored in the physiological sensor. The sensor, once implanted in the eye, can then be used to obtain a measured value for the physiological characteristic. The sensor can compare the measured value of the physiological characteristic to the target value of the physiological characteristic and then control an action to reduce the difference between the measured value of the physiological characteristic and the target value of the physiological characteristic. As discussed herein, in some embodiments, the action can be releasing a drug to treat intraocular pressure or regulating the outflow of aqueous humor from the eye. In some embodiments, the physiological sensor1000may be used as a closed continuous IOP monitoring and control system to give a clinician who is managing a glaucoma patient the ability to design and implement an individualized pharmacotherapy regimen that is controlled by the physiological sensor1000based on predetermined IOP targets set by the clinician. Generally, a physician managing a glaucoma patient can establish a target level of intraocular pressure which he or she feels is suited to the patient to reduce the risk of disease progression. In selecting the target pressure, the physician may take into account a number of factors, including but not limited to, current/baseline IOP, family history, optic nerve head status, retinal nerve fiber layer evaluation, and visual field effects. Although numerous studies have found that lower pressures reduce the risk of progression, the clinician tends to select a target pressure that strikes an appropriate balance between risk of progression and the side effects and morbidity associated with the interventions required to reach and maintain the target pressure. With a closed continuous IOP monitoring system, the physician or other user could select a target pressure and program the system to instruct a drug delivery device to administer a pre-defined dose of, for example, a hypotensive medication in response to specific IOP measurement criteria. Additionally, or alternatively, the system could instruct the patient to administer a specific topical medication in response to specific outputs. This allows the system to administer only the amount of drug necessary to consistently maintain IOP at or below the target pressure. For example, the physician could select a target pressure of 16 mm Hg for a patient. The patient can be implanted (e.g., at the trabecular meshwork) with a device such as intraocular physiological sensor1000that continuously administers a therapeutic level of a drug, such as a prostaglandin analogue. The patient can also be implanted with a device in the suprachoroidal space that contains a drug such as an alpha agonist. However, this second drug may only be delivered in the event that the patient's average IOP, as measured by the implanted device, exceeds 18 mm Hg for a set period of time. In another example, a physician may select a target pressure, such as 18 mm Hg. The patient can be implanted with a device in the trabecular meshwork that continuously administers a therapeutic level of a drug, such as a prostaglandin analogue. The implanted monitoring device may communicate to the patient (e.g., via an external device worn by the patient) to administer a topical dose of a drug such as timolol in the event that the patient's average IOP exceeds, for example, 21 mm Hg for a period of time, such as six hours. In another example, a physician may select a target pressure of, for example, 18 mm Hg. The patient can be implanted with a device in the trabecular meshwork that administers a dose of a drug, such as prostaglandin analogue, only when the patient's IOP exceeds the target value for some set period of time. In addition to the closed continuous IOP monitoring and control system that provides for controlled management of IOP with drugs, a similar closed continuous IOP monitoring and control system could be provided using a stent to manage IOP by regulating the outflow of aqueous humor. In such embodiments, the outflow of the stent and/or the release of a drug can be controlled based upon, for example, intraocular pressure measurements from the physiological sensor in conjunction with a target intraocular pressure value that may be programmed into the sensor by a clinician. A similar closed continuous monitoring and control system could also be implemented with glucose concentration measurements. For example, a clinician or the patient could set a target glucose level. The implanted intraocular physiological sensor could then monitor glucose concentration levels and control an insulin pump (e.g., with a wireless command interface) to administer insulin based on a comparison between the measured glucose value and the target value. Alternatively, and/or additionally, the physiological sensor could communicate to the patient (e.g., via an external device worn by the patient) a notification to eat or to exercise based on the comparison between the measured glucose value and the target value. Various embodiments of implants disclosed herein may be implanted by an ab interno procedure or an ab externo procedure. The “ab interno” procedure is herein intended to mean any procedure that creates an opening from the anterior chamber into eye tissue within or forming a boundary of the anterior chamber, usually in a backward direction. This ab interno procedure may be initiated through the scleral wall or cornea wall into the anterior chamber as a first step. The term “ab externo” procedure is herein intended to mean any procedure that creates an opening on the scleral wall and proceeds inwardly toward the anterior chamber. For example, in some “ab externo” procedures, an instrument is passed through or contacts Schlemm's canal before entering trabecular meshwork and approaching the anterior chamber. In some embodiments, ab externo procedures may pass through some or all of the thickness of the scleral wall in order to position a sensor device inside the eye or within the scleral wall. A less-invasive ab externo procedure can be accomplished by tunneling through scleral tissue with a needle or cannula such that the tip of the needle or cannula accesses the anterior chamber or the suprachoroidal space. A sensor device may then be advanced through the needle or cannula to be at least partially located within the anterior chamber, or at least partially located within the suprachoroidal space. After delivery of the sensor device within the eye, the needle or cannula is withdrawn, leaving a self-sealing track through the sclera. Implantation by this method may result in some or all of the sensor device residing within scleral tissue, or between the sclera and the conjunctiva. Implants may be placed in the eye using an applicator, such as a pusher, guidewire, forceps or other suitable device. The applicator may also be a delivery instrument including but not limited to that disclosed in U.S. Application Publication No. 2002/0133168 or that disclosed in U.S. Pat. No. 7,331,984 which has energy stored in the instrument for delivering one or more implants. The contents of these two documents are hereby incorporated by reference herein in their entireties. Some embodiments of applicator have trephining capability, wherein a cutting or tissue penetration feature or mechanism forms part of the applicator for purposes of making a hole or opening in eye tissue to allow for implanting and/or securing an implant within the eye. In some embodiments, an implant may be self-trephining such that it makes its own opening. One embodiment of delivery apparatus includes a handpiece, an elongate body, a holder and a delivery mechanism. In some embodiments, the delivery mechanism is an actuator. The handpiece has a distal end and a proximal end. The elongate body is connected to the distal end of the handpiece. At least the distal portion of the elongate body is sized and configured to be placed through a incision in the sclera or cornea, including at or near the limbus, and into an anterior chamber of the eye. The holder is attached to the distal portion of the elongate tip and is configured to hold and release the implant. The deployment mechanism or actuator is on the handpiece and serves to release the implant from the holder. In some embodiments, the holder comprises a clamp. The clamp may comprise a plurality of claws configured to exert a clamping force onto at least a portion, usually the proximal portion, of the implant. The holder may also comprise one or more flanges, bumps or other raised regions which utilize friction to hold the device or which engage a corresponding feature on the implant. The holder may also comprise a recessed area or groove at or near the end of the elongate body for retaining an implant or a portion thereof. In some embodiments, the apparatus further comprises a spring within the handpiece that is configured to be loaded when the one or more implants are being held by the holder, the spring being at least partially unloaded upon actuating the actuator, allowing for release of an implant from the holder. The deployment mechanism of the delivery apparatus may include a push-pull type plunger, push button or trigger that is operated to cause delivery of an implant, such as by releasing at least some tension from a spring in an actuator mechanism or by causing at least one portion of the delivery device to move relative to another portion of the delivery device and/or an implant. In some embodiments, an actuator may be used to operate a trocar or cutting device to allow for consistent and predictable formation of an opening in eye tissue. The elongate portion of the device may be flexible or made of a flexible material, such as a flexible wire. The distal portion can have a deflection range, preferably of about 45 degrees from the long axis of the handpiece. The elongate portion of the device may be curved to aid in reaching the anterior angle on the opposite side of the eye from where the opening is made into the anterior chamber. The delivery apparatus can further comprise an irrigation port in the elongate tip. In some embodiments, the delivery device is adapted to deliver more than one implant into the eye without having to remove the device from the eye between implantations. The implants delivered may be any combination of sensor, drainage device, micropump, drug delivery device and any combination of the foregoing, including devices that may include one or more of the foregoing functions. For example, a delivery device may deliver a sensor-type implant and a combination drainage/drug delivery implant, an IOP sensor and two drainage implants, a IOP sensor and a drug delivery implant, and the like. A device for delivering multiple implants may include an elongate body sized to be introduced into an eye through an incision in the eye and a plurality of implants positioned on or in the elongate body. The elongate body may further comprise an actuator that serially dispenses the implants from the elongate body for implanting in eye tissue. A method of implanting one or more implants includes inserting an instrument into an eye through an incision, and utilizing the instrument to deliver a first implant into or onto eye tissue at a first location. Other embodiments include utilizing the instrument to deliver a second implant into or onto eye tissue at a second location, without removing the instrument from the eye between the deliveries of the implants. The incision may be made into the sclera or cornea, including at or near the limbus. In some embodiments, the incision is small so as to be self-sealing. In other embodiments, one or two stitches may be needed to close the opening once the implantation procedure is completed and the delivery device removed from the eye. In some embodiments, the incision is about 1 mm in length. The placement and implantation of the implant(s) may then be performed using a gonioscope or other imaging equipment used in eye surgery, as known in the art. During implantation, the delivery instrument may be advanced through an insertion site or incision and advanced to desired eye tissue. In some embodiments, the advancement is either transocularly or posteriorly into the anterior chamber angle. Using the anterior chamber angle as a reference point, the delivery instrument can be advanced further in a generally posterior direction to drive the implant into the iris, inward of the anterior chamber angle. The delivery device may be used to implant one or more implants at any location in the eye, including the trabecular meshwork, Schlemm's canal, supraciliary space, suprachoroidal space, and the like. Optionally, based on the implant structure, the implant may be laid within the anterior chamber angle, taking on a curved shape to match the annular shape of the anterior chamber angle. It is preferred, however, that an implant be secured to tissue, such as by using an anchor, adhesive, friction or other force, or at least not be free to move within the anterior chamber so as to minimize damage to delicate eye tissue such as the corneal endothelium. Once the delivery device and implant are at the desired location in the eye, an opening may be made in ocular tissue. This may be done, for example, using the distal end of the elongate portion of the delivery device or with a self-trephining implant. The implant is then delivered to the tissue. Delivery may be done by using a deployment mechanism. For example, a pusher tube may be advanced axially toward the distal end of the delivery instrument, such that as the pusher tube is advanced, the implant is also advanced. When the implant is in the desired position, the delivery instrument may be retracted, leaving the implant in the eye tissue. Another implant may then be implanted at another location in the eye, or the delivery device may be removed from the eye. In other embodiments, the delivery instrument is used to force the implant into a desired position by application of a continual implantation force, by tapping the implant into place using a distal portion of the delivery instrument, or by a combination of these methods. Once the implant is in the desired position, it may be further seated by tapping using a distal portion of the delivery instrument. Alternatively, the device may be implanted by using the actuator to drive an implant into tissue using stored energy, such as from a spring or other energy storage means. In one embodiment, the implant is affixed to intraocular tissue. In one embodiment, this additional affixation may be performed with a biocompatible adhesive. In other embodiments, one or more sutures may be used or one or more tissue anchors may be used. In another embodiment, the implant is held substantially in place via the interaction of the implant body's outer surface and the surrounding tissue of the anterior chamber angle. A device may also use some combination of the foregoing affixation methods. Various intraocular physiological sensors are described herein. As further described herein, in some embodiments, such sensors include fluid channels, or other types of shunts. As discussed herein, in some embodiments, the sensor/shunt is inserted from a site transocularly situated from the implantation site. The delivery instrument can be sufficiently long to advance the sensor/shunt transocularly from the insertion site across the anterior chamber to the implantation site. At least a portion of the instrument can be flexible. Alternatively, the instrument can be rigid. The instrument can comprise a plurality of members longitudinally moveable relative to each other. In some embodiments, at least a portion of the delivery instrument is curved or angled. In some embodiments, a portion of the delivery instrument is rigid and another portion of the instrument is flexible. In some embodiments, the delivery instrument has a distal curvature. The distal curvature of the delivery instrument may be characterized as a radius of approximately 10 to 30 mm, and preferably about 20 mm. In some embodiments, the delivery instrument has a distal angle. The distal angle may be characterized as approximately 90 to 170 degrees relative to an axis of the proximal segment of the delivery instrument, and preferably about 145 degrees. The angle can incorporate a small radius of curvature at the “elbow” so as to make a smooth transition from the proximal segment of the delivery instrument to the distal segment. The length of the distal segment may be approximately 0.5 to 7 mm, and preferably about 2 to 3 mm. In some embodiments, the instruments have a sharpened forward end and are self-trephinating, i.e., self-penetrating, so as to pass through tissue without pre-forming an incision, hole or aperture. Alternatively, a trocar, scalpel, or similar instrument can be used to pre-form an incision in the eye tissue before passing the sensor/shunt into such tissue. For delivery of some embodiments of the ocular sensor/shunt, the instrument can have a sufficiently small cross section such that the insertion site self seals without suturing upon withdrawal of the instrument from the eye. An outer diameter of the delivery instrument preferably is no greater than about 18 gauge and is not smaller than about 32 gauge. For clarification and avoidance of doubt, all delivery devices disclosed herein may be used to deliver any implant disclosed herein, including, but not limited to, a sensor, a shunt or drainage device, and combinations thereof, to any portion of the eye, and preferably those that may be accessed from the anterior chamber. Delivery devices may also deliver more than one device, preferably without having to remove the delivery device from the eye between implantations. For delivery of some embodiments of the ocular sensor/shunt, the incision in the corneal tissue is preferably made with a hollow needle through which the sensor/shunt is passed. The needle has a small diameter size (e.g., 18 or 19 or 20 or 21 or 22 or 23 or 24 or 25 or 26 or 27 or 28 or 29 or 30 or 31 or 32 gauge) so that the incision is self sealing and the implantation occurs in a closed chamber with or without viscoelastic. A self-sealing incision also can be formed using a conventional “tunneling” procedure in which a spatula-shaped scalpel is used to create a generally inverted V-shaped incision through the cornea. In a preferred mode, the instrument used to form the incision through the cornea remains in place (that is, extends through the corneal incision) during the procedure and is not removed until after implantation. Such incision-forming instrument either can be used to carry the ocular sensor/shunt or can cooperate with a delivery instrument to allow implantation through the same incision without withdrawing the incision-forming instrument. Of course, in other modes, various surgical instruments can be passed through one or more corneal incisions multiple times. Once into the anterior chamber, a delivery instrument can be advanced from the insertion site transocularly into the anterior chamber angle and positioned at a location near the scleral spur. Using the scleral spur as a reference point, the delivery instrument can be advanced further in a generally posterior direction to drive the sensor/shunt into eye tissue at a location just inward of the scleral spur toward the iris. The placement and implantation of the sensor/shunt can be performed using a gonioscope or other conventional imaging equipment. The delivery instrument preferably is used to force the sensor/shunt into a desired position by application of a continual implantation force, by tapping the sensor/shunt into place using a distal portion of the delivery instrument, or by a combination of these methods. Once the sensor/shunt is in the desired position, it may be further seated by tapping using a distal portion of the delivery instrument. The delivery instrument can include an open distal end with a lumen extending therethrough. Positioned within the lumen is preferably a pusher tube that is axially movable within the lumen. The pusher tube can be any device suitable for pushing or manipulating the sensor/shunt in relation to the delivery instrument, such as, for example, but without limitation a screw, a rod, a stored energy device such as a spring. A wall of the delivery instrument preferably extends beyond pusher tube to accommodate placement within the lumen of a sensor/shunt. The sensor/shunt can be secured in position. For example, the sensor/shunt can be secured by viscoelastic or mechanical interlock with the pusher tube or wall. When the sensor/shunt is brought into position adjacent the tissue in the anterior chamber angle, the pusher tube is advanced axially toward the open distal end of the delivery instrument. As the pusher tube is advanced, the sensor/shunt is also advanced. When the sensor/shunt is advanced through the tissue and such that it is no longer in the lumen of the delivery instrument, the delivery instrument is retracted, leaving the sensor/shunt in the eye tissue. Some embodiments can include a spring-loaded or stored-energy pusher system. The spring-loaded pusher preferably includes a button operably connected to a hinged rod device. The rod of the hinged rod device engages a depression in the surface of the pusher, keeping the spring of the pusher in a compressed conformation. When the user pushes the button, the rod is disengaged from the depression, thereby allowing the spring to decompress, thereby advancing the pusher forward. In some embodiments, an over-the wire system is used to deliver the sensor/shunt. The sensor/shunt can be delivered over a wire. Preferably, the wire is self-trephinating. The wire can function as a trocar. The wire can be superelastic, flexible, or relatively inflexible with respect to the sensor/shunt. The wire can be pre-formed to have a certain shape. The wire can be curved. The wire can have shape memory, or be elastic. In some embodiments, the wire is a pull wire. The wire can be a steerable catheter. In some embodiments, the wire is positioned within a lumen in the sensor/shunt. The wire can be axially movable within the lumen. The lumen may or may not include valves or other flow regulatory devices. In some embodiments, the delivery instrument comprises a trocar. The trocar may be angled or curved. The trocar can be rigid, semi-rigid or flexible. In embodiments where the trocar is stiff, the sensor/shunt can be, but need not be relatively flexible. The diameter of the trocar can be about 0.001 inches to about 0.01 inches. In some embodiments, the diameter of the trocar is 0.001, 0.002, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, or 0.01 inches. In some embodiments, delivery of the sensor/shunt is achieved by applying a driving force at or near the distal end of the sensor/shunt. The driving force can be a pulling or a pushing applied generally to the end of the sensor/shunt. The instrument can include a seal to prevent aqueous humor from passing through the delivery instrument and/or between the members of the instrument when the instrument is in the eye. The seal can also aid in preventing backflow of aqueous humor through the instrument and out the eye. Suitable seals for inhibiting leakage include, for example, an o-ring, a coating, a hydrophilic agent, a hydrophobic agent, and combinations thereof. The coating can be, for example, a silicone coat such as MDX™ silicone fluid. In some embodiments, the instrument is coated with the coating and a hydrophilic or hydrophobic agent. In some embodiments, one region of the instrument is coated with the coating plus the hydrophilic agent, and another region of the instrument is coated with the coating plus the hydrophobic agent. The delivery instrument can additionally comprise a seal between various members comprising the instrument. The seal can comprise a hydrophobic or hydrophilic coating between slip-fit surfaces of the members of the instrument. The seal can be disposed proximate of the drainage sensor/shunt when carried by the delivery instrument. Preferably, the seal is present on at least a section of each of two devices that are machined to fit closely with one another. In some embodiments, the delivery instrument can include a distal end having a beveled shape. The delivery instrument can include a distal end having a spatula shape. The beveled or spatula shape can have a sharpened edge. The beveled or spatula shape can include a recess to contain the sensor/shunt. The recess can include a pusher or other suitable means to push out or eject the sensor/shunt. The delivery instrument further can be configured to deliver multiple shunts. In some embodiments, when multiple shunts are delivered, the shunts can be arranged in tandem, as described in greater detail below. For delivery of some embodiments of the ocular sensor/shunt, the implantation occurs in a closed chamber with or without viscoelastic. The shunts may be placed using an applicator, such as a pusher, or they may be placed using a delivery instrument having energy stored in the instrument, such as disclosed in U.S. Patent Publication 2004/0050392, filed Aug. 28, 2002, the entirety of which is incorporated herein by reference and made a part of this specification and disclosure. In some embodiments, fluid may be infused through the delivery instrument or another instrument used in the procedure to create an elevated fluid pressure at the distal end of the sensor/shunt to ease implantation. In some embodiments, the sensor/shunt is implanted through the fibrous attachment of the ciliary muscle to the sclera. This fibrous attachment zone extends about 0.5 mm posteriorly from the scleral spur, as shown between the two arrows (1020) inFIG.11. In some embodiments it is desirable to deliver the sensor/shunt ab interno across the eye, through a small incision at or near the limbus. The overall geometry of the system makes it advantageous that the delivery instrument incorporates a distal curvature, or a distal angle. In the former case, the sensor/shunt can be flexible to facilitate delivery along the curvature or can be more loosely held to move easily along an accurate path. In the latter case, the sensor/shunt can be relatively rigid. The delivery instrument can incorporate a sensor/shunt advancement element (e.g. pusher) that is flexible enough to pass through the distal angle. In some embodiments, during clinical use, the sensor/shunt and delivery instrument can be advanced together through the anterior chamber32from an incision at or near the limbus, across the iris, and through the ciliary muscle attachment until the sensor/shunt outlet portion is located in the uveoscleral outflow pathway (e.g. exposed to the suprachoroidal space34defined between the sclera38and the choroid40). The operator can then simultaneously push on a pusher device while pulling back on the delivery instrument, such that the sensor/shunt outlet portion maintains its location in the uveoscleral outflow pathway. The sensor/shunt is released from the delivery instrument, and the delivery instrument is retracted proximally. The delivery instrument then can be withdrawn from the anterior chamber through the incision. In some embodiments, a viscoelastic can be injected into the suprachoroidal space to create a chamber or pocket between the choroid and sclera which can be accessed by a sensor/shunt. Such a pocket could expose more of the choroidal and scleral tissue area, and increase uveoscleral outflow, causing a lower IOP. In some embodiments, the viscoelastic material can be injected with a 25 or 27 G cannula, for example, through an incision in the ciliary muscle attachment or through the sclera (e.g. from outside the eye). The viscoelastic material can also be injected through the sensor/shunt itself either before, during or after implantation is completed. In some embodiments, a hyperosmotic agent can be injected into the suprachoroidal space. Such an injection can delay IOP reduction. Thus, hypotony can be avoided in the acute postoperative period by temporarily reducing choroidal absorption. The hyperosmotic agent can be, for example glucose, albumin, HYPAQUE™ medium, glycerol, or poly(ethylene glycol). The hyperosmotic agent can breakdown or wash out as the patient heals, resulting in a stable, acceptably low IOP, and avoiding transient hypotony. FIG.11shows a meridional section of the anterior segment of the human eye and schematically illustrates another embodiment of a delivery instrument1130that can be used with embodiments of shunts described herein. InFIG.11, arrows1020show the fibrous attachment zone of the ciliary muscle1030to the sclera1040. The ciliary muscle is part of the choroid1050. The suprachoroidal space34is the interface between the choroid and the sclera. Other structures in the eye include the lens1060, the cornea1070, the anterior chamber32, the iris1080, and Schlemm's canal1090. In some embodiments, it is desirable to implant a sensor/shunt through the fibrous attachment zone, thus connecting the anterior chamber to the uveoscleral outflow pathway, in order to reduce the intraocular pressure in glaucomatous patients. In some embodiments, it is desirable to deliver the sensor/shunt with a device that traverses the eye internally (ab interno), through a small incision in the limbus. The delivery instrument/sensor/shunt assembly may be passed between the iris and the cornea to reach the iridocorneal angle. Therefore, the height of the delivery instrument/sensor/shunt assembly (dimension1095inFIG.11) preferably is less than about 3 mm, and more preferably less than 2 mm. The suprachoroidal space between the choroid and the sclera generally forms an angle1110of about 55 degrees with the optical axis1115of the eye. This angle, in addition to the height requirement described in the preceding paragraph, are features to consider in the geometrical design of the delivery instrument/sensor/shunt assembly. The overall geometry of the system makes it advantageous that the delivery instrument1130incorporates a distal curvature1140, as shown inFIG.11, or a distal angle1150, as shown inFIG.12. The distal curvature (FIG.11) is expected to pass more smoothly through the corneal or scleral incision at the limbus. However, the sensor/shunt preferably is curved or flexible in this case. Alternatively, in the design ofFIG.12, the sensor/shunt may be mounted on the straight segment of the delivery instrument, distal of the “elbow” or angle1150. In this case, the sensor/shunt may be straight and relatively inflexible, and the delivery instrument can incorporate a delivery mechanism that is flexible enough to advance through the angle. In some embodiments, the sensor/shunt is a rigid tube, provided that the sensor/shunt is no longer than the length of the distal segment1160. The distal curvature1140of delivery instrument1130may be characterized as a radius of approximately 10 to 30 mm, and preferably about 20 mm. The distal angle of the delivery instrument depicted inFIG.12may be characterized as approximately 90 to 170 degrees relative to an axis of the proximal segment1170of the delivery instrument, and preferably about 145 degrees. The angle incorporates a small radius of curvature at the “elbow” so as to make a smooth transition from the proximal segment1170of the delivery instrument to the distal segment1160. The length of the distal segment1160may be approximately 0.5 to 7 mm, and preferably about 2 to 3 mm. FIGS.13,14A and14Bshow an example of a delivery instrument for a sensor/shunt. In some embodiments, the sensor/shunt is delivered through a needle with a cutting tip2140. The sensor/shunt can be loaded inside of the shaft of the needle for delivery through the eye. The needle can be curved on the side of the needle opposite to the beveled opening2150, as illustrated inFIG.14A. This allows the curved part of the needle to take a “downward” direction without appreciably affecting the effective height of the device. This geometry can be advantageous for passage through the anterior chamber between the iris and the cornea. At the same time, the curve permits the sharp tip of the needle to follow the angle of the ciliary muscle/sclera interface (angle1110shown inFIG.11). Further, the design of the curved tip as shown inFIG.14Acan limit the depth of the dissection of the ciliary muscle from the sclera to the minimum depth necessary to cut through the fibrous attachment tissue. This depth is estimated to be less than about 0.5 mm. In addition, the curvature of the tip act as a baffle to redirect the sensor/shunt as it is pushed distally outward through the needle. In other embodiments, the needle cutting tip is straight, as illustrated inFIG.14B. FIG.15shows another embodiment of a system that can be used to perform a variety of methods or procedures. The sensor/shunt2200is deflected “downward” at an angle that parallels the suprachoroidal space. The depth of insertion can be determined by the length of the pushrod2220, whose travel can be limited by the stop2230. It is preferred that the pushrod ends at the proximal edge of the opening of the needle2240. In this way, the sensor/shunt will not be pushed below the anterior surface of the ciliary muscle. FIG.16shows another embodiment of a system that can be used to perform a variety of methods or procedures. In the illustrated embodiment, the sensor/shunt2200is mounted on a curved or angled shaft2250. In some embodiments, both the sensor and the shunt are mounted on the shaft. In other embodiments, while the sensor may be connected to the shunt, only the shunt is mounted on the shaft (e.g., the sensor may be tethered to the shunt, which is mounted on the shaft). The shaft2250can be tubular (as shown), or solid and the distal end2260can be sharpened. The sensor/shunt2200can be curved with approximately the same radius as the delivery device, so that the sensor/shunt can be relatively stiff and still slide along the shaft. In some embodiments, a pusher tube2270causes the sensor/shunt to slide distally along the shaft and be released. In operation in some embodiments, the sharpened end2260makes an incision in the fibrous tissue attaching the ciliary muscle and the sclera. In some embodiments, the distance between the sharpened tip2260and the distal end of the sensor/shunt determines how deeply the tissue may be incised. After making the cut, the operator can advance the pusher tube2270while holding the mounting shaft2250fixed. This action causes the sensor/shunt2200to be advanced into the incision. The distance of sensor/shunt advance can be determined by the length of the pusher tube2270, whose travel can be limited by a stop, as depicted inFIG.15. Further embodiments of the invention incorporate injection of viscoelastic through the sensor/shunt or through the shaft2250in order to accomplish posterior dissection of the suprachoroidal tissue, thereby creating a volumetric chamber or reservoir for aqueous humor. In addition or in the alternative, therapeutic agents (e.g., a hyperosmatic agent) can be delivered into the suprachoroidal space through the sensor/shunt2220or through the shaft2250. FIG.17shows another embodiment of a system that can be used to perform a variety of methods or procedures. Delivery of the sensor/shunt2700is achieved by applying a driving force at or near the distal end2710of the sensor/shunt2700using, for example, a pusher2720. The driving force can be a pushing force applied to the distal end2710of the sensor/shunt2700. The delivery device alternatively can extend through or around the sensor/shunt to supply a pulling force to draw the sensor/shunt through tissue. FIG.18shows another embodiment of a system2800that can be used to perform a variety of methods or procedures. A spring-loaded pusher system2800can be used for delivery of a sensor/shunt. The spring-loaded pusher2810preferably includes a button2820operably connected to a hinged rod device2830. The distal portion2835of the hinged rod device2830engages a depression2840in the surface of the pusher2810, keeping the spring2850of the pusher2810in a compressed conformation. When the user pushes downwards2860on the button2820, the distal portion2835of the hinged rod device2830is disengaged from the depression2840, thereby allowing the spring2850to decompress, thereby advancing the pusher2810forward. FIG.19shows another embodiment of a system that can be used to perform a variety of methods or procedures. In the illustrated embodiment, an over-the-wire system2920is used to deliver the sensor/shunt2900. In some embodiments, both the sensor and the shunt are mounted on the wire. In other embodiments, while the sensor may be tethered or otherwise connected to the shunt, only the shunt portion is mounted on the wire. Such embodiments may be advantageous because the sensor portion may not need to have a passage through which the wire can be threaded, and this may simplify design of the sensor and layouts of electronic components. The sensor/shunt2900can have a generally rounded distal portion2915at the distal end. The radius of the distal portion can be about 70 to about 500 microns. The distal portion2915can gradually increase in cross-sectional size towards the proximal direction, preferably at a generally constant taper or radius or in a parabolic manner as shown. In some embodiments, the implant comprises one or more openings2905communicating with an interior chamber, or lumen, within the implant. Preferably, the edges of the openings are rounded as shown. In addition or in the alternative, the implant can include other exterior surface irregularities (e.g., annular grooves) to anchor the implant, as described above. In some embodiments the sensor/shunt can have a flange2910at a proximal portion of the implant. Preferably, the flange has sharp edges and corners as shown. The sharp edges and corners tend to inhibit cell proliferation near the influent end of the implant. The wire or similar elongated structure2920can function as a trocar. Preferably, the wire2920is self-trephinating. The radius of the tip of the distal portion2930of the wire2920can be about 10 to about 500 microns. In some embodiments, the radius of the tip of the distal portion2930of the wire2920can be about 70 to about 200 microns. The distal portion2930of wire2920can increase in cross-sectional size towards the proximal direction. In some embodiments, the increase can be in a parabolic manner. In the depicted embodiment, the wire2920has a distal portion2930having a gradual increase in cross-sectional size in a parabolic manner towards the proximal direction. The wire2920can have a rounded distal tip of the distal portion2930. In other embodiments, the distal portion can be tapered. The wire can be superelastic, flexible, or relatively inflexible with respect to the sensor/shunt. The wire can be pre-formed to have a certain shape. The wire can be curved. The wire can have shape memory, or be elastic. In some embodiments, the wire is a pull wire. The wire can be a steerable catheter. In some embodiments, a pusher2950can be used in conjunction with the wire2920to aid in delivery of the sensor/shunt2900. The pusher2950can be used to hold the sensor/shunt2900in place as the wire2920is withdrawn proximally after the sensor/shunt2900has been delivered to a desired location. The pusher2950, trocar2920and implant2900preferably are sized to fit and move (e.g., slide) within an outer sheath or needle. The needle preferably includes a sharpened distal end to penetrate tissue (e.g., corneal tissue) when accessing the anterior chamber of the eye. FIG.20is a block diagram of an example embodiment of an intraocular pressure sensor2000. The intraocular pressure sensor2000can include any of the components or features described herein with respect to any other physiological sensor. However, no component or feature should necessarily be understood as being required in the intraocular pressure sensor2000unless explicitly stated otherwise. In addition, any of the implantation techniques and tools described herein can be used for implanting the intraocular pressure sensor2000at the desired location within the eye, and any sensing, control, and/or treatment method disclosed herein with respect to any other sensor can be used with the intraocular pressure sensor2000. In some embodiments, the intraocular pressure sensor2000includes a housing assembly2100(described herein with respect toFIGS.21-29), a pressure sensing module2050, a wireless transmitter/antenna2085, a controller module2070, a measurement storage module2060, and a battery2040. Each of these components is not necessarily required in every embodiment of the intraocular pressure sensor2000, however. Further, the intraocular pressure sensor2000can also include other components. In some embodiments, some or all of the components of the intraocular pressure sensor2000are provided as part of an integrated circuit2075(illustrated as the dashed box inFIG.20) on a chip, though some components can also be provided as discrete components with, for example, electrical connections to the integrated circuit2075. In some embodiments, the pressure sensing module2050includes a capacitor whose capacitance varies in response to the pressure of the medium where the module is located. In some embodiments, the pressure sensing module2050includes a microelectromechanical system (MEMS). For example, as discussed further herein, the pressure sensing module2050can include a fixed capacitor plate in proximity to a movable membrane or diaphragm. The distance, and/or contact, between the movable membrane and the fixed capacitor plate varies in response to the pressure applied by, for example, the aqueous humor when the intraocular pressure sensor2000is implanted within the eye. This is detected as a change in capacitance of the MEMS device. In some embodiments, the pressure sensing module2050is a contact-mode sensor that is capable of measuring intraocular pressure from about 3 mmHg to about 50 mmHg with about ±0.5 mmHg resolution. In some embodiments, the cavity underneath the movable membrane or diaphragm is sealed under vacuum, and the pressure sensing module responds over the range of approximately 600 to 900 mmHg absolute pressure. In such embodiments, ambient pressure can be measured independently outside the body and subtracted from the absolute sensor pressure to yield the intraocular pressure. In some embodiments, the signal (capacitance) varies in an approximately linear fashion relative to the intraocular pressure. In one example, the capacitance may increase from approximately 5 picofarads (pF) to approximately 20 pF over the approximately linear range of pressure. In some embodiments, the pressure sensing module2050is electrically connected to a capacitance-to-digital converter2056that outputs a value which is indicative of the capacitance of the pressure sensing module2050, and, therefore, the detected pressure. This value can be provided to the control module2070. In some embodiments, the intraocular pressure sensor also includes one or more reference capacitors2052. The reference capacitor2052can also be connected to the capacitance-to-digital converter2056, and can be used to provide a reference value for calibration and/or temperature compensation. Pressure measurements from the pressure sensing module2050can be stored in the measurement storage module2060. In some embodiments, the measurement storage module2060is a solid-state memory that is provided on an integrated circuit2075and is communicatively coupled to, for example, the controller module2070and/or the pressure sensing module2050. For example, the measurement storage module2060can be a 16 kB static random-access memory (SRAM), though other types of memory and/or capacities can also be used. In some embodiments, the controller module2070performs data compression on the pressure measurements before storing them in the measurement storage module2060. By performing data compression, the measurement storage module2060can hold more measurements. This can allow for more frequent measurements and/or less frequent data downloading events. In some embodiments it may be advantageous to use a relatively simple compression technique so as to preserve computational resources. One example data compression algorithm could be to store the difference between sequential measurements rather than the measurements themselves. This technique could allow for fewer bits per measurement to be used by the measurement storage module2060. As shown inFIG.20, the intraocular pressure sensor2000can also include a controller module2070. The controller module2070can perform any of the functions described with respect to, for example, other controller modules disclosed herein. For example, in some embodiments, the controller module2070can be programmed to cause the pressure sensing module2050to perform measurements at predetermined times and/or regular intervals determined by, for example, the MSTR clock2071. For example, in some embodiments the controller module2070is programmed to obtain a measurement every hour. Each recorded/reported measurement can, however, be calculated from multiple measurements by the pressure sensing module2050. For example, the controller module2070can be programmed to obtain multiple measurements (e.g., three measurements) at relatively short intervals (e.g., 30 seconds). These can then be averaged and recorded/reported as a single measurement at the measurement storage module2060. This process can then be repeated at longer intervals (e.g., hourly). The intraocular pressure sensor2000illustrated inFIG.20includes a battery module2040to power components such as the controller module2070and the transmitter module/antenna2085. In some embodiments, the physical dimensions of the battery are approximately 0.3 mm×4.5 mm, or smaller. The battery can have a power rating of approximately 0.8 μAh, or greater. Such a power rating is estimated to provide sufficient power for at least approximately 180 days between recharges. In some embodiments, the sleep power consumption of the intraocular pressure sensor2000is on the order of picowatts while the active power consumption is on the order of nanowatts. It should be understood, however, that the size and power rating of the battery module2040could be different than the figures listed above, as could the power consumption of the intraocular pressure sensor2000. The foregoing specifications are merely examples. For instance, in some embodiments, the battery module2040is capable of powering the intraocular pressure sensor2000for at least approximately 90 days. In some embodiments, the battery module2040is rechargeable by an external device, as discussed further herein. For example, the battery module2040can be recharged wirelessly via inductive coupling or RF energy from an external device. The battery module2040can also be charged by solar power or by an infrared laser (in which case, the intraocular pressure sensor2000can include an appropriate photovoltaic cell to convert the solar or infrared laser light to electrical power). The intraocular pressure sensor2000can also include a transmitter/antenna2085. The transmitter/antenna2085can be used to wirelessly transmit pressure measurements stored in the measurement storage module2060to an external reader device. The external reader device can be integrated into a pair of eyeglasses that are worn by the patient to download pressure measurements from the sensor2000. The transmitter/antenna2085can also serve a dual purpose of receiving power wirelessly in order to charge the battery module2040(e.g., while the stored measurements are being downloaded). For example, the transmitter/antenna2085can receive power wirelessly by inductive coupling. A wireless charging device can be integrated in the same eyeglasses that include the external reader device for downloading data from the intraocular pressure sensor2000. The transmitter/antenna2085can transmit measurement data and receive power for recharging the battery module2040either simultaneously, or one at a time (in either order). In some embodiments, the antenna2085is made of a conductor such as silver, gold, platinum, tungsten, and/or alloys of the same and the like. In some embodiments, the antenna2085is made of an alloy of about 92% platinum and about 8% tungsten. As discussed further herein, the antenna2085can have a spiral shape with a diameter that is somewhat smaller than the inner diameter of the main housing2102so as to allow the antenna to both fit within the housing and encompass other components provided therein. FIG.21is a perspective view of an example embodiment of the main housing2102portion of the housing assembly2100for the intraocular pressure sensor2000. In some embodiments, the main housing2102is a generally cylindrical tube. The main housing2102can be made of, for example, ceramic. Ceramic offers the benefit of providing a moisture barrier that is more effective than plastic but without shielding signals to/from the transmitter/antenna2085like metal would. The ceramic can be, for example, at least about 90% alumina. One possible ceramic material is ˜99.99% alumina, while another possible ceramic material is ˜90% alumina and ˜10% zirconia. In other embodiments, the main housing2102can be made of a high barrier plastic, such as HDPE or the like. In such embodiments, the plastic could be coated with ceramic in order to improve the moisture barrier characteristics. Such embodiments would be useful for making more complex main housing shapes (e.g., main housing shapes that include a bend or curvature). In addition, in some embodiments, components inside of the main housing2102(e.g., electronic components) can be coated with a hydrophobic material to further reduce the chance of damage if liquid were to infiltrate the main housing2102. Components inside of the main housing2102, including the integrated circuit2075, the antenna2085, etc., can also (or alternatively) be coated with electrically insulative coatings (e.g., a Parylene coating) in order to help prevent electrical short circuits. The main housing2102can be designed to mate with a separate tip cap2104and/or a separate sensor cap2108(illustrated inFIGS.27-29), both of which can, in some embodiments, be removable. The tip cap2104can have a generally rounded end, as illustrated inFIG.21. The rounded end can ease insertion of the sensor2000within certain intraocular anatomical structures, such as, for example, the supraciliary/suprachoroidal space. The tip cap2104can be designed to press into one end of the main housing2102. The fit between the tip cap2104and the main housing2102can be liquid-tight. For example, the tip cap2104can include one or more seals (e.g., O-rings, a solder ring, a eutectic ring, a compression bond, such as a gold-gold compression bond, etc.) to prevent liquid from entering the main housing2102at the interior junction between the tip cap2104and the main housing. The sensor cap2108can be designed to press into the other end of the main housing2102opposite from the tip cap2108. It, too, can be designed to form a moisture barrier seal with the main housing2102using, for example, one or more seals (e.g., O-rings, a solder ring, a eutectic ring, a compression bond, such as a gold-gold compression bond, etc.), as discussed herein. The press in fit of the tip cap2104and the sensor cap2108, with certain types of moisture barrier seals (e.g., O-rings), can be advantageous because the housing assembly2100(including the main housing2102, the tip cap2104, and the sensor cap2108) can be assembled and sealed without necessarily requiring bonding, heat curing, vacuum deposition/other coatings, electrical impulse, etc. The main housing2102can also include one or more anchoring members, such as a barbs2106, for anchoring the sensor2000within, or at, a desired intraocular anatomical structure. In some embodiments, the anchoring members are raised ridges or barbs2016that rise from the outer surface of the main housing2102and encircle all, or a portion of, the circumference of the main housing at each anchoring location. The main housing2102can be sized and shaped to fit any desired intraocular anatomy. In some embodiments, however, the intraocular pressure sensor2000is designed to be implanted within the supraciliary/suprachoroidal space of the eye. In such embodiments, the housing assembly2100may have a length of about 2-8 mm and/or a diameter of about 0.3-0.6 mm. In some embodiments, the length of the housing assembly2100is about 5.4 mm and the diameter is about 0.48 mm. FIG.22illustrates the location of the intraocular pressure sensor2000within the supraciliary/suprachoroidal space between the ciliary body/choroid and the sclera. As discussed herein, the intraocular pressure sensor2000can be fixed in this location by one or more anchoring members2106. The ciliary body is contiguous with the choroid. The supraciliary/suprachoroidal space is normally a potential space at the interface between the ciliary body/choroid and sclera. The space may open to accommodate an implant such as the intraocular pressure sensor2000.FIG.22illustrates an example of placement of the intraocular physiological sensor2000(which may be partially or completely located within the anterior chamber of the eye; or may be partially or completely located within the supraciliary/suprachoroidal space). In some embodiments, at least the sensor cap end of the intraocular pressure sensor2000extends into the anterior chamber so as to provide ready access to the aqueous humor in order to take pressure measurements thereof. Though not illustrated, in other embodiments, the intraocular pressure sensor2000can be sized and shaped to be implanted in or at other intraocular anatomical features, including but not limited to the sclera, the iris, the ciliary body, the trabecular meshwork, or Schlemm's canal. FIG.23is a replica ofFIG.21in which the main housing2102is shown as being see-through. The tip cap2104and the barbs2106are still visible. Also visible through the see-through main housing2102are the antenna2085the O-ring seals2105of the tip cap2104, and a portion of the sensor cap2108, including its O-ring seals2109.FIG.23also shows a carrier member2072upon which various components can be mounted. For example, the battery module2040and the integrated circuit2075can be mounted upon the carrier member2072. The carrier member2072can include electrical contacts, connections, signal traces, etc. formed on its surface, or embedded within its volume in order to provide electrical connections between various components mounted on, or connected to, the carrier member2072. In some embodiments, the carrier member2072is a glass backbone (e.g., borosilicate glass). As discussed further herein, the carrier member2072can be designed to physically mate with the tip cap2104and/or the sensor cap2108in order to provide further structural integrity to the sensor2000and to fix the carrier member-mounted components within the main housing2102. In order to allow for this physical mating, the carrier member2072, the tip cap2104, and/or the sensor cap2108can each include one or more connectors, cutouts, projections, etc. that are designed to mate, attach, join, etc. with a complementary structure on the adjacent portion of the housing assembly2100. As illustrated inFIG.23, in some embodiments, the antenna2085is a conductor that spirals around the carrier member2072about the interior circumference of the main housing2102. The antenna2085can be connected to the carrier member2072by, for example, solder so as to provide an electrical connection to the integrated circuit2075mounted on the carrier member2072. FIG.24is a replica ofFIG.21but with the main housing2102removed. Once again visible are the antenna2085, the glass backbone carrier member2072, the tip cap2104and its O-ring seals2105, and a portion of the sensor cap, including its O-ring seals2109.FIG.24also shows the battery module2040mounted on the carrier member2072. As discussed further herein, the glass backbone carrier member2072is configured to physically mate with the tip cap2104and/or the sensor cap2108. For example, the glass backbone carrier member2072is illustrated as having a generally rectangular cross-section. Each of the tip cap2104and the sensor cap2108can include a correspondingly-shaped inner cutout into which the ends of the carrier member2072can be inserted. As discussed further herein, the cutout and the carrier member2072can each include electrical contacts, or other connections, that are designed to come into contact with each other with the carrier member is mated with the sensor cap2108. FIG.25is a replica ofFIG.24but with the antenna2085removed. As before, the glass backbone carrier member2072, the tip cap2104and its O-ring seals, a portion of the sensor cap2108, including its O-ring seals2105, and the battery module2040are visible. With the antenna2085now removed,FIG.25also shows the integrated circuit2075mounted on the glass backbone carrier member2072. As discussed herein, the integrated circuit can include, for example, the controller module2070, the measurement storage module2060, etc. FIG.26illustrates another example embodiment of the intraocular pressure sensor2000with a curved housing2602. In contrast toFIGS.21-25, which illustrate an embodiment where the intraocular pressure sensor2000has a generally straight main housing2102,FIG.26shows a tubular main housing2602having a curved profile. The main housing2602is somewhat curved along its longitudinal dimension in order to more closely match the shape of the anatomy (e.g., the supraciliary/suprachoroidal space) where it is to be implanted. It should be understood, however, that different curvatures can also be used. Moreover, the shape and/or dimensions of the intraocular pressure sensor2000can be adapted to be implanted in or at other intraocular anatomical features, as well.FIG.26also shows the tip cap2104, the sensor cap2108, and anchoring barbs2602. These features are as described elsewhere herein. FIG.27illustrates a top perspective view and a cross-sectional view of a non-recessed sensor cap2108that is designed to be at least partially inserted into the main body2102of the housing. In some embodiments, the sensor cap2108is made of glass (e.g., borosilicate glass), though other materials may also be possible. The non-recessed sensor cap2108includes a plug portion2115and a head portion2114. The plug portion2115can be sized so as to be snugly insertable into the main body2102of the housing assembly2100. For example, the diameter of the plug portion2115can be equal to, or just smaller, than the inner diameter of the main body2102. The plug portion2115also includes one or more O-ring seals2109. The O-ring seals include grooves that are formed into the plug portion2115around its circumference. The grooves are sized to fit one or more O-rings formed of an elastomeric, resilient material, such as rubber. When the plug portion2115is pressed into the main body2102, the O-ring seals2109form a moisture barrier to prevent aqueous humor from entering the main body2102at the junction of the sensor cap2108and the main body2102. Although the plug portion2115is illustrated with O-ring seals, other types of seals can also be used at the interior junction between the sensor cap2108and the main body2102. For example, a solder ring or a eutectic ring can be provided around the plug portion2115of the sensor cap2108. When the plug portion2115is inserted into the main body2102, the solder or eutectic ring can deform. The solder or eutectic ring can be made to reflow upon heating, thus forming a moisture barrier and/or a hermetic seal. Another type of seal that can be used in some embodiments is a compression bond. For example, the plug portion2115and/or the main body2102can be provided with a ring structure made of gold, or some other malleable material. The ring structure(s) can be located so as to be engaged when the plug portion2115is inserted into the main body2102. The ring structure(s) can be deformed upon application of this insertion force, thus creating a moisture barrier and/or a hermetic seal. It may be possible to create this type of compression seal without needing to apply heat after the sensor cap2108is inserted into the main body2102. It should be understood that any type of seal described herein can be used alone, or in conjunction with any other type of seal described herein. Further, other types of seals besides those described herein can also be used. The non-recessed sensor cap2108also includes a head portion2114. The head portion2114has a larger diameter than the plug portion2115and the inner diameter of the main body2102. Thus, the head portion2114abuts against the end of the main body2102when the sensor cap is inserted. In some embodiments, the diameter of the head portion can be the same as, or similar to, the outer diameter of the main housing2102. A pressure sensing module2050is built into the head portion2114of the sensor cap2108. As discussed herein, in some embodiments, the pressure sensing module2050is a capacitive MEMS pressure sensor. The capacitive MEMS pressure sensor includes a fixed capacitor plate2110and a movable diaphragm2111. The movable diaphragm2111is exposed to the aqueous humor when the intraocular pressure sensor2000is implanted into the eye. Accordingly, the movable diaphragm2111deflects in response to the pressure exerted against it by the aqueous humor. As a result, the distance and/or contact between the movable diaphragm2111and the fixed plate2110of the capacitor changes in response to the pressure exerted by the aqueous humor. This results in a detectable change in capacitance. In some embodiments, the fixed capacitor plate2110and/or the movable diaphragm2111are formed of silicon, though other materials are also possible. The capacitive MEMS pressure sensor2050is connected to the carrier member2072and/or the integrated circuit2075by feedthrough conductors2113. Specifically,FIG.27illustrates two feedthrough conductors2113. One of the feedthrough conductors2113is an electrical contact with the movable diaphragm2111, while the other feedthrough conductor2113is in electrical contact with the fixed capacitor plate2110. As illustrated inFIG.27, the feedthrough conductors2113are formed longitudinally through the body of the sensor cap2108. As will be discussed further herein, the feedthrough conductors2113extend from the pressure sensor2050to a junction between the sensor cap2108and the carrier member2072. In some embodiments, the feedthrough conductors2113are formed of silicon, though they could also be formed of other conductive materials. FIG.28illustrates a bottom perspective view of the non-recessed sensor cap2108.FIG.28shows the plug portion2115, the head portion2114, the pressure sensing module2050, and the O-ring seals2109, as discussed herein.FIG.28also shows the locations of the feedthrough conductors2113that are formed within the body of the sensor cap2108. In addition,FIG.28shows a cutout2116that is formed in the bottom of the plug portion2115. The cutout2116is shaped and sized so as to receive the carrier member2072when the sensor cap2108is inserted into the main body2102. The carrier member2072can include electrical contacts that electrically connect to the feedthrough conductors2113when the carrier member2072is plugged into the cutout formed in the plug portion2115of the sensor cap2108. The electrical connection between the carrier member2072and the sensor cap2108can be accomplished by mechanical contact between electrical contacts located on the respect parts and/or by soldering. In this way, electrical signals can be conducted from the flexible diaphragm2111and the fixed conductor plate2110of the pressure sensing module2050to the carrier member2072and then to the integrated circuit2075. FIG.29illustrates two cross-sectional views of the non-recessed sensor cap2108, as inserted into the main housing2102of the intraocular pressure sensor2000. The top cross-sectional view is taken along section C-C, and the bottom cross-sectional view is taken along section B-B, which is orthogonal to section C-C. The top and bottom cross-sectional views are illustrative of the plug portion2115, the head portion2114, the O-ring seals2109, and the movable diaphragm2111and fixed capacitor plate2110of the pressure sensing module2050, which are described herein. The top and bottom cross-sectional views also show the cutout2116which is formed in the plug portion2115of the sensor cap2108. The cutout2116is shaped and sized to receive the carrier member2072. The top cross-sectional view inFIG.29shows the thickness dimension of the cutout2116, while the bottom cross-sectional view shows the width dimension of the cutout2116. Each dimension of the cutout2116can be shaped and sized according to the corresponding dimensions of the carrier member2072, so as to snugly receive the carrier member. Also, as illustrated in the bottom cross-sectional view, the feedthrough conductors2113pass through the sensor cap2108from the MEMS capacitor to the cutout2116, which, in some embodiments, is the junction of the sensor cap with the carrier member2072. FIG.30illustrates a cross-sectional view of an example embodiment of a recessed sensor cap3108, as inserted into the main housing2102of the intraocular pressure sensor2000. Unlike the non-recessed sensor cap2108illustrated inFIGS.27-29, the recessed sensor cap3108includes the plug portion2115but not the head portion2114. Thus, the recessed sensor cap3108can be inserted entirely into the main housing2102of the intraocular pressure sensor2000. The main housing2102can include integrated plug stops2101to prevent the recessed sensor cap3108from being inserted past the desired point within the main housing2102. The sensor cap3108also includes a cutout2116for mating with the carrier member2072, as discussed herein. In the embodiment illustrated inFIG.30the, capacitive MEMS pressure sensor, including the fixed capacitor plate2110and the movable diaphragm2111are integrated into the top of the plug portion2115rather than a head portion (e.g.,2114). One or more feedthrough conductors2113can be formed longitudinally through the sensor cap3108to extend from the pressure sensor (e.g., the fixed capacitor plate2110and the movable diaphragm2111) to the junction of the sensor cap3108with the carrier member2072and/or the integrated circuit2075in order to electrically connect the pressure sensor to the integrated circuit. FIG.31illustrates an embodiment of the exterior junction3100between the main body2102of the housing and the sensor cap2108before (FIG.31A) and after (FIG.31B) forming a seal3110at the junction3100. The exterior junction3100between the main body2102and the sensor cap2108may be an entry point for aqueous humor to enter the main body2102of the housing assembly. Although any such aqueous humor may still be sealed out of the main body2102by the internal O-rings2109(or another type of seal), it may be desirable in some embodiments to form a moisture barrier seal at the exterior junction3100in addition to, or in place of, the internal moisture barrier provided by the O-rings2109(or another type of seal).FIG.31Billustrates a moisture barrier seal3110formed at the exterior junction3100between the main body2102and the sensor cap2108. In some embodiments, the moisture barrier seal3110can be provided by sputtering gold, or some other material, on/into the junction3100. In this way, the moisture barrier seal3110can help prevent aqueous humor from entering the main body2102. Various sensors have been described herein for taking pressure measurements within the eye. Pressure measurements taken by a sensor located in the anterior chamber110or otherwise in fluid communication with the aqueous humor can be, for example, absolute pressure measurements which are referenced against a vacuum. Such pressure measurements may reflect not only the gauge pressure within the eye but also the atmospheric pressure outside of the eye. As a result, variations in atmospheric pressure can cause variations in the pressure measurements taken by such intraocular sensors. Variations in the data which are due to atmospheric pressure may be undesirable in some circumstances because they are independent of the pressure variations caused by physiological processes which are typically the subject of clinical and diagnostic interest. Therefore, in some embodiments, it is advantageous to obtain pressure measurements which are not subject to variations in atmospheric pressure or which are affected by variations in atmospheric pressure to a lesser degree. Absolute pressure measurements recorded by a sensor implanted in the eye can be processed to subtract out the effect of atmospheric pressure in order to determine the gauge pressure within the eye. This can be done, for example, by measuring not only absolute pressure within the eye using an intraocular sensor of the type described herein but by also concurrently measuring atmospheric pressure using an external sensor outside of the body. Alternatively, localized barometric weather data can be used to determine the atmospheric pressure at the time and location where the absolute pressure measurements were recorded within the eye. In either case, the atmospheric pressure measurement can be subtracted, or otherwise removed, from the measurement of absolute pressure within the eye in order to determine the gauge pressure within the eye. Unless it is specifically stated otherwise or it is evident from context, both types of measurements of the pressure in the anterior chamber of the eye (i.e., absolute pressure and gauge pressure) may be referenced herein as IOP. It is also possible, however, to determine gauge IOP measurements without necessarily using an external pressure sensor or location-based barometric data to obtain atmospheric pressure measurements which are used to correct absolute pressure measurements made within the eye. This can be done by, for example, using an implanted sensor to record pressure measurements at, or with access to, an anatomical location where the pressure is equal to, or correlated with, atmospheric pressure. One such anatomical location is the sub-conjunctival space located between the conjunctiva and the sclera.FIGS.32-35describe various embodiments of implanted pressure sensors which take advantage of this fact in order to provide pressure measurements which are reflective of the gauge IOP within the eye with reduced impact from the effects of atmospheric pressure. FIG.32is a schematic illustration of an implantable intraocular physiological sensor system3200located in a human eye100which can be used to obtain measurements of the gauge pressure within the anterior chamber of the eye. For reference, various anatomical features of the eye100are labeled inFIG.32. For example,FIG.32shows the lens106, the anterior chamber and aqueous humor110, the cornea112, the ciliary body115, the sclera118, the choroid124, and the conjunctiva126. As shown inFIG.32, the intraocular physiological sensor system3200can be implanted partially within the anterior chamber110, partially in the suprachoroidal space between the choroid124and the sclera118, and/or partially in the sub-conjunctival space between the conjunctiva126and the sclera118. It should be understood that the intraocular physiological sensor system3200is not necessarily drawn to scale. In some embodiments, the intraocular physiological sensor system3200is an elongate tube which includes a first pressure sensor3210generally located at or near one end and a second pressure sensor3220generally located at or near the opposite end. The first and second pressure sensors can be capacitive sensors, though other types of pressure sensors may also be suitable. As shown inFIG.32, the physiological sensor system3200can be implanted within the eye such that the first pressure sensor3210is located in, or in fluid communication with, the anterior chamber110. Meanwhile, the position, size, dimensions, and/or shape of the physiological sensor system3200can be such that the second pressure sensor3220at the opposite end is simultaneously located in, or in fluid communication with, the sub-conjunctival space between the conjunctiva126and the sclera118. This placement can be accomplished by, for example, forming a tunnel through the sclera118using a sharp tool and inserting the intraocular physiological sensor system3200through that scleral tunnel using an ab interno approach. In some cases, access to the scleral tunnel can be achieved via the suprachoroidal space between the sclera118in the choroid124. Other surgical implantation techniques, such as the ones described herein, can also be used. In some embodiments, the tunnel through the sclera118can be formed such that a substantially fluid-tight seal is formed between the tissue of the sclera118and the physiological sensor system3200in order to limit the exchange of fluid between the anterior chamber110and the sub-conjunctival space. When the physiological sensor system3200is implanted, it has the capability to take concurrent measurements of the pressures within the anterior chamber and the sub-conjunctival space. Measurements taken by the first pressure sensor3210may be reflective of the absolute pressure within the anterior chamber110, including the effects of atmospheric pressure outside of the eye. Meanwhile, measurements taken by the second pressure sensor3220may be reflective of the atmospheric pressure outside of the eye. For example, the pressure measured in, or with access to, the sub-conjunctival space may equal, or be correlated with, the atmospheric pressure outside of the eye. Concurrent pressure measurements can be taken from both the first pressure sensor3210and the second pressure sensor3220. The atmospheric pressure measurement taken by the second pressure sensor3220can then be subtracted, or otherwise removed, from the absolute pressure measurement taken by the first pressure sensor3210. The resulting value will be a gauge IOP value which is affected by atmospheric pressure to a lesser degree than the absolute pressure measurement taken by the first pressure sensor3210. In some embodiments, the gauge IOP value can be obtained according to the following equation: Gauge IOP=PSensor1−PSensor2, where PSensor1equals a pressure measurement taken by the first pressure sensor3210and PSensor2equals a pressure measurement taken by the second pressure sensor3220. Alternatively, the gauge IOP value can be obtained according to the following equation: Gauge IOP=PSensor1−f(PSensor2), where f(PSensor2) is a function designed to account for any differences which may exist between the pressure in the sub-conjunctival pressure and the atmospheric pressure. For example, the sub-conjunctival pressure may be slightly less than the atmospheric pressure due to the osmotic pressure of interstitial fluid. Therefore, f(PSensor2) may include a negative offset to account for this difference. Other forms for the function f(PSensor2) can also be used. FIG.33is a schematic illustration of the physiological sensor system3200shown inFIG.32. As shown, the physiological sensor system3200can be an elongate tube with the first pressure sensor3210and the second pressure sensor3220located at opposite ends. The tube can be at least partially hollow inside so as to house a battery3230or other power source, as described herein with respect to other sensor embodiments. In addition, the tube can include circuitry3240, such as a processor, a memory for storing pressure measurements, a transmitter/receiver, an antenna, etc., as disclosed herein. Any of the features of other sensor embodiments described herein can also be applied to the physiological sensor system3200. The pressure measurements taken by the first pressure sensor3210and the second pressure sensor3220can be stored locally in a memory in the device. The pressure measurements can be taken concurrently by the first pressure sensor3210and the second pressure sensor3220. In some embodiments, the concurrent measurements are substantially simultaneous. Measurements can be taken by both pressure sensors at regular intervals. In some embodiments, measurements are taken by both sensors on a substantially continual basis. As already discussed, the measurement data taken by the first pressure sensor3210and the second pressure sensor3220can be processed to determine the gauge pressure within the eye. This processing can be performed on board the physiological sensor system3200. Alternatively, the processing can be performed externally after the raw measurement data has been downloaded by an external reader device. AlthoughFIGS.32and33illustrate one example embodiment of an implanted sensor whose shape and positioning allows for concurrent anterior chamber and sub-conjunctival space pressure measurements to be taken, other shapes, positions, and/or configurations may also be possible. For example, in some embodiments, the first pressure sensor3210and the second pressure sensor3220may be provided in separate sensor housings. Each such sensor housing could include its own power source, memory for storing pressure measurements, and/or other electronic components described herein. In addition, each sensor housing could include suitable electronics (e.g., transmitter, antenna, etc.) to wirelessly communicate with each other and/or an external reader device. In some embodiments, the separate sensor housings could be tethered. For example, the sensor housing for the second sensor3220could include a tether to the sensor housing for the first sensor3210. This tether could be used, for example, to communicate pressure measurements between the sensor housings. One of the tethered sensors may be positioned in the anterior chamber, while the other may be positioned under the conjunctiva. WhileFIGS.32and33illustrate an embodiment of a physiological sensor system3200which can be used to determine gauge pressure within the anterior chamber of the eye based on mathematical processing of measurement data from two different sensors, it is also possible to obtain a direct measurement of the differential pressure between the anterior chamber and the sub-conjunctival space. A direct measurement of this differential pressure is also an indicator of the gauge pressure within the eye. FIG.34Aillustrates an example embodiment of a capacitive absolute pressure sensor3430, whileFIG.34Billustrates an example embodiment of a capacitive differential pressure sensor3440. The absolute pressure sensor3430includes a flexible top electrode3432and a bottom electrode3434. The two electrodes are separated by a sealed vacuum cavity3436. When the absolute pressure sensor3430is exposed to a pressure-transmitting medium, such as a liquid, the flexible top electrode3432is deflected by an amount that is dependent upon the pressure of the medium. This deflection of the top electrode3432in turn alters the capacitance between the two electrodes. This capacitance can be measured in order to determine the pressure of the medium. In contrast, the differential pressure sensor3440measures the difference in pressures between two pressure-transmitting media. The differential pressure sensor3440also includes a flexible top electrode3442and a bottom electrode3444. The flexible top electrode3442can be exposed to a first pressure-transmitting medium located on its side which is opposite the bottom electrode. But the other side of the flexible top electrode3442can be exposed to a second pressure-transmitting medium. As shown inFIG.34B, this can be accomplished via a channel3446that leads from a cavity between the top electrode3442and the bottom electrode3444to the second pressure-transmitting medium. The embodiment illustrated inFIG.34Bis just one example of a differential pressure sensor. Other designs are also possible. In some embodiments, a differential pressure sensor3442can be implanted in the eye such that the first pressure-transmitting medium in contact with the sensor is the aqueous humor from the anterior chamber, while the second pressure-transmitting medium is liquid in the sub-conjunctival space. FIG.35Aillustrates a first embodiment of a differential sensor3540which can obtain measurements indicative of the gauge pressure within the anterior chamber of the eye. The differential sensor3540can have an elongate tubular body. In the illustrated embodiment, two spaced-apart electrodes3542,3544are provided at the right end of the differential sensor3540, while a channel3560extends from the space between the electrodes, through the tubular body, to the left end of the differential sensor3540. As discussed above with respect toFIG.34B, one of the electrodes3542is flexible. The differential pressure sensor3540can be positioned as illustrated inFIG.32such that one end of the device is in, or in fluid communication with, the anterior chamber of the eye, while the other end of the device is in, or in fluid communication with, the sub-conjunctival space. As shown inFIG.35A, in this instance, the flexible electrode3542is located in the anterior chamber, while the opposite end of the device is located in the sub-conjunctival space. With this positioning inside the eye, the aqueous humor transmits the pressure in the anterior chamber to the right side of the flexible electrode3542. Meanwhile, the channel3560allows pressure from the sub-conjunctival space to be transmitted to the left side of the flexible electrode3542. Thus, the capacitance sensed between the two electrodes3542,3544is representative of the differential pressure between the anterior chamber and the sub-conjunctival space. Since the pressure in the sub-conjunctival space is equal to, or correlated with, atmospheric pressure, the differential pressure sensor3540measures the pressure inside the anterior chamber with respect to atmospheric pressure. This measurement represents the gauge pressure within the anterior chamber. Although not illustrated, the channel3560can be open to the sub-conjunctival space or it can be primed with a non-compressible fluid and sealed with a flexible membrane such that pressure from the sub-conjunctival space can be transmitted through the flexible membrane to the non-compressible fluid in the channel3560and ultimately to the flexible electrode3542via the non-compressible fluid. In addition, in some embodiments, the differential sensor3540can be positioned in the eye in the direction opposite of what is illustrated, such that the electrodes3542,3544are directly exposed to the sub-conjunctival space while the channel3560provides access to the anterior chamber. FIG.35Billustrates a second embodiment of a differential sensor3540which can obtain measurements indicative of the gauge pressure within the anterior chamber of the eye. This second embodiment is similar to the first embodiment shown inFIG.35Aexcept that the electrodes3542,3544are provided in the middle portion of the elongate differential pressure sensor rather than at one end. Consequently, channels3560are formed through the elongate body on both sides of the flexible electrode3542so as to provide access from the pressure-transmitting media in the anterior chamber on one side and the sub-conjunctival space on the other side. These channels3560can be open or sealed with flexible membranes and primed with a non-compressible fluid in order to transmit pressure from the anterior chamber and the sub-conjunctival space to the flexible electrode3542. Correlation of Absolute IOP Measurements with Concurrent Atmospheric Pressure Measurements As just discussed, the IOP measurements taken by some of the implantable sensor devices described herein may be absolute IOP measurements which are affected by variations in atmospheric pressure. In such cases, the absolute IOP measurements can be corrected to reflect the gauge IOP within the eye—typically the clinically-relevant value—by compensating for the effect of atmospheric pressure on those measurements. This can be done by, for example, concurrently measuring atmospheric pressure using a local external sensor outside of the body and then subtracting the atmospheric pressure measurement from the absolute IOP measurement taken by the implanted sensor. In practice, this may be difficult to accomplish because the atmospheric pressure experienced by an individual can vary significantly over relatively short periods of time; therefore inadequate synchronization between the timing of the atmospheric pressure measurement and the absolute IOP measurement inside the eye may cause inaccuracies in the calculated gauge IOP value. FIG.36Ais a graph3600of the atmospheric pressure measured by a barometer worn by a user. A signal3602shows the variation in atmospheric pressure over a period of about 140 hours.FIG.36Bshows a zoomed-in portion3604of the signal3602during the period of time from hour 60 until hour 80. During this period of time, the signal3602shows that the atmospheric pressure usually varied relatively slowly over time, most likely due to normal changes in weather conditions. An example of this kind of relatively slow weather-induced variation over time is shown by the signal3602from hour 69 until hour 73. However, the signal3602also shows that there were sudden, relatively large magnitude changes that also occurred. Examples of these types of sudden large changes in measured atmospheric pressure are seen in the signal3602approximately during hour 63 (i.e., between 62 and 63 on the graph), hour 68 (i.e., between 67 and 68 on the graph), hour 75 (i.e., between 74 and 75 on the graph), and hour 77 (i.e., between 76 and 77 on the graph). These sudden large changes in atmospheric pressure may have been the result of changes in altitude experienced by the user while he or she was driving up or down hills, moving between different floors of a building, etc. Because relatively large changes in atmospheric pressure such as these can occur over relatively short periods of time, care should be taken when correlating an atmospheric pressure measurement with an absolute IOP measurement for use in calculating a gauge IOP value: if the external and internal pressure measurements are offset from one another in time by too great a degree, there is a potential that the gauge IOP value derived from the two measurements may be significantly affected by one of these sudden, large magnitude changes in atmospheric pressure, thus reducing the accuracy of the gauge IOP value. This difficulty in correlating internal absolute IOP measurements with external atmospheric pressure measurements can be exacerbated if there is some amount of drift over time in the accuracy of the respective timekeeping devices used by the external and implanted pressure measurement devices. For example, as shown inFIG.20, an IOP sensor implant may include a timekeeping device, such as a timer or a clock, which may be used to indicate the times at which pressure measurements are to be taken. Design constraints may favor or require the use of relatively simple timer or clock circuits. For example, cost, power consumption, and/or circuit size constraints may favor or require the use of less advanced timers and/or clocks, such as ones which do not include a piezoelectric resonator, in implantable sensor devices. These timers and/or clocks may be less accurate than more advanced versions which would require, for example, larger numbers of circuit elements, a larger amount of space within the implantable sensor device, and/or more power. As a result, the timekeeping accuracy of the timers and/or clocks which may be used in implantable devices of the sort described herein may drift over time. In addition, these timekeeping devices may be more affected by temperature variations. Even a timekeeping drift of just 0.1%, for example, can result in relatively large inaccuracies over periods of time such as days, weeks, or months. As a result, there may be a time offset between an atmospheric pressure measurement taken by an external device and an internal absolute IOP measurement taken by an implant within the patient's eye even though the respective timekeeping elements used by the two devices may indicate that the two measurements were taken concurrently. And, of course, a significant change in either the atmospheric pressure or the absolute IOP could occur during that time offset. If so, it would result in an inaccurate calculation of the gauge IOP value. FIGS.36C and36Dare graphs3610,3620, respectively, which illustrate examples of the inaccuracies in calculated gauge IOP values which may result from time offsets between absolute IOP measurements and atmospheric pressure measurements.FIG.36Cillustrates the simulated effect of a timer inaccuracy of 0.1%, whileFIG.36Dillustrates the simulated effect of a timer inaccuracy of 1%. In both graphs3610,3620, the plotted gauge IOP values were calculated by subtracting atmospheric pressure values from absolute IOP values at regular intervals (e.g., every hour). In these simulated examples, the absolute IOP signal and the atmospheric pressure signal were designed to result in a constant gauge IOP signal of 16 mmHg. That is, although the absolute IOP signal and the atmospheric pressure signal both varied in time similarly to what is shown inFIGS.36A and36B, the difference between these signals—gauge IOP—was designed to be constant. If the gauge IOP values had been calculated using absolute IOP values and atmospheric pressure values that were perfectly synchronized in time, then the plotted gauge IOP values would have remained constant at 16 mmHg. However, in these simulations, time drift was introduced between the atmospheric pressure values and the respective absolute IOP values used to calculate the gauge IOP values. As shown in the graphs3610,3620, within just a few days or less, the simulated timer inaccuracies resulted in a lack of synchronization between the respective absolute IOP values and atmospheric pressure values, which in turn caused large, false variations in the calculated gauge IOP values.FIGS.37A and37Billustrate example methods for avoiding these types of inaccuracies. FIG.37Aillustrates an example method3700afor calculating a gauge IOP value using one or more atmospheric pressure measurement(s) from an external device and one or more absolute IOP measurement(s) from a sensor implant within the patient's eye. The method begins at block3710awhere the appointed times and/or intervals are set for capturing absolute IOP measurements, using a sensor implant in the patient's eye, and atmospheric pressure measurements, using an external device. For example, both the external device and the implanted sensor device can be set (e.g., using onboard software, firmware, and/or hardware) so as to capture measurements at, or around, times T1, T2, T3, . . . , etc. These times may be independently measured by the external device and the sensor implant using, for example, their respective onboard timekeeping devices. As already discussed, even though the respective timekeeping devices used by the external device and the sensor implant may be initially synchronized, timekeeping drift may cause them to gain or lose time with respect to one another, thus losing synchronization. As a result, the sensor implant may actually capture absolute IOP measurements at times T1±Δ1, T2±∴2, T3±Δ3, etc. Similarly, the external device may actually capture atmospheric pressure measurements at times T1±δ1, T2±δ2, T3±δ3, etc., where Δnand δnmay be different and unknown. Additionally, or alternatively, both the external device and the sensor implant can be set so as to capture measurements at, or around, intervals I1, I2, I3. . . . But, once again, there may be unknown offsets between the instants in time when the external atmospheric pressure measurements and the absolute IOP measurements are actually captured. At block3720a, the sensor implant captures an absolute IOP measurement within the patient's eye at the appointed time/interval (e.g., T1, I1). This measurement may be stored in an onboard memory or transmitted to an external reader device, etc. At least partially concurrently, at block3730a, the external device captures a plurality of measurements during a window of time that may extend before and/or after the appointed time/interval (e.g., T1, I1). The length of the atmospheric pressure measurement window can be determined based on, for example, the timekeeping drift that is present in the sensor implant timekeeping device and/or the timekeeping device used by the external device which measures atmospheric pressure. The amount of timekeeping drift can specify an uncertainty window around each appointed measurement time during which a measurement may occur. In some embodiments, the atmospheric pressure measurement window can be set to be at least as large as this timekeeping uncertainty window. For example, in some embodiments the external device captures a plurality of measurements during a 20 minute window of time centered on the appointed time/interval. These atmospheric pressure measurement windows are indicated inFIG.36Bby the bars3606which are centered at each hour on the hour. The number of atmospheric pressure measurements captured during each atmospheric pressure measurement window can be selected based on, for example, the length of the window of time, the desired sampling rate, the available memory, etc. During the window of time, atmospheric pressure measurements may be captured, for example, every second, every 10 seconds, every minute, etc. At block3740a, the measurements captured during the atmospheric pressure measurement window of time can be analyzed to determine the amount of variation that is present in the measurements. For example, the atmospheric pressure measurements can be analyzed to determine whether, during the window around the appointed measurement time/interval, the variation between the atmospheric pressure measurement values stays within a selected range (e.g., variation ≤10 mmHg, ≤5 mmHg, ≤1 mmHg, ≤10%, ≤1%, etc.) The calculation of the variation in the atmospheric pressure signal can be done according to any appropriate mathematical technique, including calculation of one or more differences, calculation of a variance or standard deviation, etc. This analysis can be performed by, for example, the external measurement device. Alternatively, the analysis can be performed by a separate processing device to which the atmospheric pressure measurements are uploaded. InFIG.36B, the unshaded bars3606aare examples of ones where the amount of variation in the measurements captured during an atmospheric pressure measurement window was within a selected acceptable range, while the shaded bars3606bare examples of ones where the amount of variation was found to be outside the selected acceptable range. At block3750a, if the variation in the atmospheric pressure measurements captured during the window of time is acceptable, then one or more of the atmospheric pressure measurements within the window can be accepted and used, together with the absolute IOP measurement captured at the appointed time/interval using the sensor implant, to calculate a gauge IOP value. For example, the atmospheric pressure measurement which is nearest in time to the appointed time/interval may be selected for use in the calculation of the gauge IOP value. Or the average of all measurements during the atmospheric pressure measurement window may be used. Or a representative atmospheric pressure value can be computed or selected from all the measurements in the atmospheric pressure measurement window in some other way. However, in these embodiments, an atmospheric pressure measurement is only accepted for use in calculating a gauge IOP value if the atmospheric pressure data are relatively stable (within prescribed limits which can be set based on the application or the desired accuracy) over the course of the atmospheric pressure measurement window. In this way, a gauge IOP value is only calculated for times when it is relatively certain that the calculated value will not be substantially negatively impacted by variations in atmospheric pressure experienced by the user during the atmospheric pressure measurement window. Alternatively, the gauge IOP value could be calculated in all cases and then only stored and/or presented to the user if the foregoing criterion is met. Or a suspect gauge IOP value (e.g., one calculated using data captured during a period of time when variation in atmospheric pressure exceeded some set threshold) can be presented to the user with a flag or notification that it is a suspect value. The calculation of a gauge IOP value according to block3750acan be performed by, for example, an external device to which atmospheric pressure measurements and IOP measurements are both uploaded. FIG.37Billustrates an example method3700bfor correlating an atmospheric pressure measurement from an external device with an absolute IOP measurement from a sensor implant for purposes of determining a gauge IOP value. The method3700bbegins at block3710b, where an external device or system which is used to capture atmospheric pressure measurements initiates a synchronization operation by wirelessly transmitting synchronization information to the sensor implant within the patient's eye. The synchronization information can be, for example, a value, such as a timestamp or a unique correlation ID number, which is associated with a particular time (e.g., the current time when the synchronization signal is transmitted), as indicated by the timekeeping device used by the external device to determine when to capture atmospheric pressure measurements. In some embodiments, the synchronization information may be wirelessly transmitted at a different frequency than that which is used to send wireless power to the implant and/or to download data from the implant. The synchronization information can be stored by the external device in association with the time of the synchronization operation, as indicated by its onboard clock or timer. The synchronization information can be stored together with the measurements of atmospheric pressure, which may also be stored in association with the times when they were captured, as indicated by the onboard clock or timer. In some embodiments, the synchronization information is transmitted by the external device at predetermined times and/or intervals. In some cases, the user may be prompted to interact with the external device so as to initiate a synchronization operation. In some embodiments, the external device used to capture atmospheric pressure measurements may be an article designed to be worn on the wrist like a watch. The external device may output an audible alarm or other prompt to remind the user to perform a synchronization operation. The synchronization operation may require the user to bring the external device in proximity to his or her eye so as to allow the sensor implant to more readily receive the synchronization information. In some embodiments the external device may transmit the synchronization information using a transmission power sufficiently high so that the user is not required to bring the external device in proximity to his or her eye. In such embodiments the external device may be located on the body of the patient, for example on the wrist of the user or hung from neck of the user, or even nearby the user such as in the same room, and it may not be required that the user bring the external device into close proximity to his or her eye. At block3720b, the sensor implant receives the synchronization information and associates it with the current time, as indicated by its onboard timekeeping device (e.g., clock or timer). The sensor implant can then store the synchronization information along with the associated time of the synchronization operation. The synchronization information can be stored together with the measurements of absolute IOP, which may also be stored in association with the times when they were captured, as indicated by the onboard timekeeping device of the sensor implant. Then, at block3730bthe sensor implant captures an absolute IOP measurement within the patient's eye at the appointed measurement time/interval. At least partially concurrently, at block3740b, the external device captures one or more atmospheric pressure measurements at and/or around the appointed measurement time (e.g., as discussed with respect toFIG.37A). After absolute IOP and atmospheric pressure measurements have been captured, they can both be uploaded, together with the synchronization information respectively stored by the two devices, to a processing device. The processing device can then, at block3750b, correlate one or more absolute IOP measurements with one or more atmospheric pressure measurements based on the synchronization information. As already mentioned, the synchronization information received from the atmospheric pressure measurement device is associated with the time indicated by its timekeeping device when the synchronization operation was performed. Similarly, the synchronization information received from the sensor implant is associated with the time indicated by its timekeeping device when the synchronization operation was performed. Thus, the synchronization information can be used to identify one or more atmospheric pressure measurements which were taken at, or approximately at, the same time as an absolute IOP measurement from the sensor implant (e.g., within minutes or, more preferably, within seconds of each other). Then, at block3760b, the processing device can calculate a gauge IOP value using the correlated absolute IOP measurement(s) and atmospheric pressure measurement(s). In other embodiments, the implant need not necessarily include a timekeeping device but may instead rely on receiving a wireless signal from an external device to initiate an IOP measurement. The external device could perform an atmospheric pressure measurement at or near the time when the wireless signal is transmitted (e.g., within 1 s, or within 10 s, or within 60 s). In some embodiments, absolute IOP measurements can be correlated with respective concurrent atmospheric pressure measurements by using signal processing techniques, such as pattern correlation. For example, both a signal made up of absolute IOP measurements taken over time and a signal made up of atmospheric pressure measurements taken over an at least partially overlapping period of time can be analyzed according to known signal processing techniques (e.g., autocorrelation, feature extraction algorithms, etc.) to identify signal features, such as peaks, patterns, etc. If matching features are identified in both signals, then one of the signals can be shifted in time with respect to the other (e.g., by the time offset between matching features) so as to correlate absolute IOP measurements and atmospheric pressure measurements which were taken concurrently. These concurrent measurements can then be used to calculate gauge IOP values. This method could be applied in addition to other synchronizing methods (e.g., as discussed with respect toFIGS.37A and37B). In some embodiments, an external device, such as the one used to measure atmospheric pressure, can emit a control signal to an IOP sensing implant which causes the implant to capture an absolute IOP measurement. The external device can capture an atmospheric pressure measurement substantially concurrently with the control signal such that the absolute IOP measurement and the atmospheric pressure measurement are taken sufficiently concurrently to avoid substantial inaccuracies in the calculation of gauge IOP values. In some such embodiments, the external device can prompt the user to initiate absolute IOP and atmospheric pressure measurements at appointed times. For example, the external device may provide an indicator such as an alarm to remind the user to initiate the measurements at an appointed time. In order to initiate the measurements, the user may, for example, actuate a button, switch, etc. on the external device. This action may 1) initiate an atmospheric pressure measurement; and 2) initiate the control signal from the external device to the implanted IOP sensing implant. As just discussed, this control signal may be used to cause the IOP sensing implant to capture an absolute IOP measurement. In such embodiments, the control signal may include, or consist of, a unique correlation ID number, or other uniquely identifying characteristic as described previously herein, which would enable the measurements of the IOP sensing implant and the external device to be correctly correlated even in the case that a control signal was not properly received by the IOP sensing implant. The external device may be provided in a kit with information which indicates that the user should bring the external device in proximity to his or her eye when performing this operation so as to improve communication of the control signal to the IOP sensing implant. In some embodiments, the IOP sensing implant may include a low power clock—which may be relatively inaccurate—to initiate a ready state in which the implant can receive a signal from an external device. For example, the low power clock may cause the implant to enter this ready state for a window of time during which a signal such as those described herein (e.g., synchronization signal, control signal, etc.) is expected to be received from an external device. This period may be, for example, a 1, 5, 10, 30, or 60 minute window about the time when a signal is expected from the external device. This scheme may be beneficial because it may allow for the use of radio signals rather than signals sent via inductive coupling. While radio signals can travel further, they may lack the power needed to wake up the implant from a sleep state. For radio signals to be used, typically the IOP sensing implant needs to have a radio circuit powered on and ready to receive the signal. It can be advantageous, though, to use the low-power clock to shut down the radio circuit except during the ready period when a signal is expected from the external device. In some embodiments, the low power clock can be synched to the correct time at various intervals by an external device (e.g., during a charging or data download interaction). Compensation for Variations in Temperature The IOP sensing implants described herein may be affected by temperature. Although the temperature inside the eye is somewhat stabilized against large swings, it can still vary by about ±5° depending on, for example, the ambient temperature and whether the eyelid is open or closed. In addition, body temperature can vary somewhat from person to person, as well as over time for an individual user, due to fever or other individualized factors. Certain components of an IOP sensing implant, such as, for example, the sensing module itself, an onboard timekeeping device, or other electronic circuitry, may be affected by such temperature variations. Therefore, in some embodiments, a temperature sensor may be provided to capture temperature measurements over time. The temperature sensor may be provided in the IOP sensing implant itself, in a secondary intraocular implant (e.g., a drug delivery implant or a drainage implant) that is communicatively coupled to the IOP sensing implant (or to an external device that is also communicatively coupled to the IOP sensing implant), and/or in an external device such as those described herein. These temperature measurements can be used to at least partially compensate for the effect of temperature variations on one or more components of the IOP sensing implant. FIG.38is a flowchart which illustrates a method3800for at least partially compensating for the effect of temperature variations on an IOP sensing implant. The method3800begins with block3810where the external ambient temperature is measured. In some embodiments, this is accomplished using a temperature sensor that is provided as part of an external device that is worn or carried by the patient. The external device can be, for example, the same device which is used to capture atmospheric pressure measurements or to download measurements from the IOP sensing implant. At block3820, the external ambient temperature is used to estimate the intraocular temperature which is being experienced by the IOP sensing implant. This can be done, for example, using calibration information which relates external ambient temperatures to intraocular temperatures based on measurements taken during controlled experiments. Then, at block3830, the estimated intraocular temperature can be used to adjust IOP measurements taken by the IOP sensing implant, the time of the implant's onboard timekeeping device, or any other characteristic of the implant which is affected by temperature. Such adjustments can be performed on IOP measurement values and/or times by a processor in post processing after data is downloaded from the implant. The adjustments may be determined using, for example, calibration data which relates one or more temperature measurements to one or more corresponding adjustments. In some embodiments, the temperature information may additionally, or alternatively, be used simply to exclude certain measurements. For example, if a temperature measurement exceeds a set threshold, lies outside a set range, varies more than a specified amount over time, etc., then IOP measurements captured during that time period can be disregarded or otherwise excluded. In other embodiments, the temperature sensor may be provided onboard the IOP sensing implant itself. In such embodiments, temperature measurements can be recorded and logged over time just as IOP measurements. The temperature measurements can likewise be downloaded from the sensing implant and used in post processing, as just discussed, to at least partially compensate for the effect of temperature variations on the sensing implant. Power Supplies The various IOP sensing implants described herein can include one or more power supply devices to provide operating power for the various components of the IOP sensing implants. In some embodiments, an IOP sensing implant can include two separate power supply devices of different types. A first power supply device can be, for example, a battery, while a second power supply device can be, for example, a capacitor or supercapacitor. These separate power supply devices can collectively supply operating power for the IOP sensing implant. While batteries can hold much greater amounts of energy than capacitors, capacitors offer the advantage of being capable of being re-charged very quickly (e.g., within just seconds or less). This characteristic is especially advantageous for supercapacitors because of their relatively large energy storage capacity as compared to other types of capacitors. Supercapacitors are capable of storing 1-2 orders of magnitude, or more, of energy per unit volume or mass than, for example, electrolytic capacitors. Unlike a solid dielectric used by other capacitors, supercapacitors may also employ, for example, electrostatic double-layer capacitance and/or electrochemical pseudocapacitance in order to store energy. Some energy storage devices may possess combinations of physical, chemical, or behavioral properties that make their classification as a battery, capacitor, or super capacitor somewhat indeterminate. In some embodiments, a supercapacitor may be considered as having 1-2 orders of magnitude less storage capacity per unit volume or mass than a battery as well as the capability to be fully charged within a comparatively short time period (e.g., 1-10 seconds) by the application of an appropriate voltage. The IOP sensing implant may include a circuit with separate physical connections to the battery and to the supercapacitor (e.g., one pair of pads for each power source). The circuit may also include a third, separate pair of pads for the inductor coil (antenna). When the external inductive field is present, the circuit may cause a voltage to be applied to both the supercapacitor and the battery, with a source current to charge both of them. The voltage may remain on while the external inductive field is present (the supercapacitor will charge relatively quickly to that voltage and the battery will continue to draw current for a longer period of time). The supercapacitor and battery can be connected to the same charge circuit in parallel with the same charging voltage applied. This configuration may be advantageous because it does not require complex charging circuitry. However, in other embodiments, there could also be two different charge circuits—one to charge the supercapacitor and another to charge the battery (possibly with different voltages and/or currents). For discharging, in some embodiments the supercapacitor and the battery are not connected in parallel. Instead, the IOP sensing implant may be powered from the supercapacitor until its charge is depleted and then the implant may switch to use the battery. Alternatively, the supercapacitor may be used to charge the battery (while the battery powers the implant). This approach could introduce energy losses during the charging of the battery, but could be an advantageous approach if, for example, the self-discharge rate of the supercapacitor is high. FIG.39Ais a graph3900awhich shows the power usage of an example IOP sensing implant in the case where the implant is powered by a battery (i.e., signal3902) and, separately, for the case where the implant is powered by a supercapacitor (i.e., signal3904). Signal3902illustrates the first case where the IOP sensing implant is powered solely by a battery. In this example, the IOP sensing implant is assumed to use 1 nAh of electrical energy per hour and the battery is assumed to have a usable storage capacity of 1 μAh. As shown by the signal3902, the plotted remaining power capacity starts at 1 μAh and linearly decreases at a rate of 1 nAh per hour until all of the stored energy in the battery is exhausted after approximately 41 days. Meanwhile, signal3904illustrates the second case where the IOP sensing implant is powered solely by a supercapacitor. In the case where the IOP sensing implant is powered at least partially by a supercapacitor, the IOP sensing implant may be part of a system which is designed to prompt the patient to perform charging interactions, or to more frequently perform charging interactions, with the IOP sensing implant. In such embodiments, an external charging device can be provided for wirelessly charging the IOP sensing implant. Wireless power transfer from the external device to the IOP sensing implant can be performed using electromagnetic energy, such as radio frequency (RF) energy, infrared (IR) energy, etc. The electromagnetic energy can be transferred by, for example, inductive coupling, propagating waves, etc. The external charging device can include, for example, a charging power source, a transmitter, and an antenna or inductive coupling element. The IOP sensing implant can likewise include an antenna or inductive coupling element to receive power from the external charging device. In addition, the external charging device can also include an output device, such as a speaker, a display, a haptic transducer, etc. The output device can be used by the external charging device to provide prompts to the patient to perform charging interactions with the IOP sensing implant. Such prompts can be provided at regular intervals (e.g., daily, every 12 hours, weekly, etc.). Or the prompts can be provided at irregular intervals based on some criterion (e.g., when the supercapacitor has a predetermined percentage of power capacity remaining). The prompts may take the form of, for example, an audible cue, such as an alarm. In other embodiments, the prompt may be a visual cue, such as a certain symbol or text on a display. In still other embodiments, the prompt may take some other form, such as, for example, a haptic cue. A charging interaction prompt can coincide with a timer synchronization prompt and/or a data download prompt. In such embodiments, use of a supercapacitor power source may have a synergistic effect because the user may already be required to perform regular timer synchronization interactions (e.g., due to time-keeping drift onboard the IOP sensing implant, as discussed herein) and/or data downloads (due to limited memory capacity) using, for example, inductive coupling. These interactions can be taken advantage of to also charge the supercapacitor. Accordingly, it may be possible to eliminate or reduce the frequency, and associated inconvenience, of battery recharges (which may otherwise require 30-45 minutes of wearing a special charging device). The charging interactions themselves can take many forms. For example, the patient may be required to manipulate a control on the external charging device, such as a button, switch, etc. Manipulation of the control can cause the external charging device to initiate the wireless transfer of power from the external charging device to the IOP sensing implant. The control can also initiate the synchronization of timekeeping devices, the downloading of data from the IOP sensing implant, etc., as discussed elsewhere herein. In some embodiments, the external charging device may include or be accompanied by usage instructions which indicate to the user that he or she should bring the external charging device in proximity to his or her eye as part of the charging interaction. Closer physical proximity between the external power charging device and the IOP sensing implant will generally improve power transfer to the implant. In some embodiments, the external charging device may repeatedly or continuously provide the prompt until sensing that the user has carried out the charging interaction. Since the power source is a supercapacitor, the charging interaction may only take seconds or less, thus making it practical to conduct frequent charging interactions. In some embodiments, the external charging device may be set to provide the charging prompt at intervals of time such that the expected energy usage of the IOP sensing implant during the interval is less than the storage capacity of the supercapacitor. For example, for the case illustrated by signal3904, the IOP sensing implant is assumed to use 1 nAh of electrical energy per hour and the supercapacitor is assumed to have a usable storage capacity of 0.2 μAh. Thus, the supercapacitor can provide sufficient energy to power the IOP sensing implant for several days. So long as the external charging device prompts the user to conduct charging interactions with the IOP sensing implant at intervals which are shorter than this expected operation time (and assuming the user actually conducts the prompted charging interactions), then the IOP sensing implant can operate continuously. For example, signal3904shows that charging interactions are prompted—and generally performed—daily. However, even if the patient ignores the charging interaction prompt for a few days at a time (as indicated by the larger teeth in the sawtooth signal waveform3904), the IOP sensing implant can still be operated continuously because the supercapacitor is capable of storing adequate energy to power the device for a few days at a time. The expected energy usage of the IOP sensing implant can be determined in a variety of ways, including experimentally during typical usage conditions or analytically based on rated power usage of the various components of the sensing implant. FIG.39Bis a graph3900bwhich shows the power usage of an example IOP sensing implant that is powered by the combination of a battery and a supercapacitor, where the capacity of the supercapacitor is less than the power usage of the implant between charging interaction times. In the example illustrated by signal3908, the IOP sensing implant consumes 1 nAh of electrical power per hour, while the battery has a storage capacity of 0.5 μAh and the supercapacitor has a storage capacity of 0.02 μAh. As just described with respect toFIG.39A, the IOP sensing implant can be part of a system which includes an external charging device which occasionally prompts the patient to perform a charging interaction to charge the supercapacitor. (As mentioned above, the charging interaction prompt can also serve as, or coincide with, timer synchronization prompts and/or data download prompts.) In the example illustrated by signal3908, the external charging device outputs the charging interaction prompt daily and the supercapacitor is therefore re-charged daily so long as the patient adheres to the prompt. This is evident from the 0.02 μAh sawtooth pattern which is evident in the signal3908, where the supercapacitor is charged and then drops in remaining capacity until being re-charged once again. The 0.02 μAh storage capacity of the supercapacitor in this example is slightly less than the expected energy usage of 0.024 μAh by the IOP sensing implant between the daily charging interaction times. For comparison purposes,FIG.39Balso includes a signal3906, which illustrates a case where the IOP sensing implant is powered solely by a battery with a storage capacity of 1 μAh—double the storage capacity of the battery represented by signal3908. As shown by the signal3906, this battery capacity is sufficient to power the IOP sensing implant for approximately 41 days. But notwithstanding the fact that the battery corresponding to signal3906has twice the capacity as the battery corresponding to signal3908, the IOP sensing implant corresponding to signal3908can operate approximately 3 times longer than the IOP sensing implant corresponding to signal3906. This is due to the presence of the supercapacitor combined with regular (e.g., daily) charging interaction. This example illustrates the synergy which can be achieved by using even a relatively small-capacity supercapacitor in conjunction with a battery to supply operating power to the IOP sensing implant. FIG.39Cis a graph3900cwhich shows the power usage of an example IOP sensing implant that is powered by the combination of a battery and a supercapacitor, where the capacity of the supercapacitor is greater than the power usage of the implant between charging interaction times. In the example illustrated by signal3912, the IOP sensing implant once again consumes 1 nAh of electrical power per hour, while the battery has a storage capacity of only 0.3 μAh and the supercapacitor has a storage capacity of 0.1 μAh. Once again, the IOP sensing implant can be part of a system which includes an external charging device which occasionally prompts the patient to perform a charging interaction to charge the supercapacitor. In the example illustrated by signal3912, the external charging device outputs the charging interaction prompt daily and the supercapacitor is therefore generally re-charged daily, though allowance is made for these charging interactions to be occasionally skipped. For comparison purposes,FIG.39Calso includes a signal3910, which illustrates a case where the IOP sensing implant is powered solely by a battery with a storage capacity of 1 μAh—more than three times the storage capacity of the battery represented by signal3912. As shown by the signal3910, this battery capacity is sufficient to power the IOP sensing implant for approximately 41 days. In contrast, the IOP sensing implant corresponding to signal3912can operate for much longer periods of time because the supercapacitor is capable of supplying all of the necessary operating power for the entire period of time between scheduled charging interaction prompts. So long as the patient adheres to these prompts and carries out the charging interactions, the battery power is not needed. However, the battery is available to supply back-up power in the event that the patient fails to adhere to one or more charging interaction prompts. FIG.40is a flowchart which illustrates a method4000for supplying operating power to an IOP sensing implant. The method4000begins at block4010where a battery and a supercapacitor are provided onboard the IOP sensing implant to provide operating power for the implant. At block4020, an external charging device is provided. At block4030, the external charging device is set to prompt the patient to initiate a charging interaction between the external charging device and the IOP sensing implant. Finally, at block4040, the external charging device wirelessly transfers power to, for example, a supercapacitor onboard the IOP sensing implant when a charging interaction is initiated. As already discussed, charging interactions can be prompted by the external charging device at, for example, regular intervals or based on satisfaction of some criterion. Laser Welding of Main Housing and Sensor Cap of IOP Sensing Implant As already discussed above, various embodiments of the IOP sensing implants disclosed herein can include a main tubular housing (e.g.,2102) and a sensor cap (e.g.,2108) which mates with the main housing, though other types of combinable housing parts can also be used. The sensor cap can be designed to press into one end of the main housing. A moisture barrier seal can be provided or formed between the sensor cap and the main housing. FIG.41illustrates an embodiment of a sensor cap2108inserted into a main housing2102with a moisture barrier seal formed therebetween. In some embodiments, the sensor cap2108has a bi-diameter design with a plug portion2115and a head portion2114. The plug portion2115can be sized so as to be snugly insertable into the main body2102of the housing. For example, the diameter of the plug portion2115can be equal to, or just smaller (e.g., <5% smaller, <1% smaller, <0.1% smaller, <0.01% smaller, <0.001% smaller), than the inner diameter of the main body2102. The head portion2114, in contrast, may have a diameter which is larger than the inner diameter of the main body2102. A shoulder therefore results at the junction between the plug portion2115and the head portion2114. When the sensor cap2108is inserted into the main housing2102, this shoulder serves as a mechanical stop which abuts against a mating surface4120of the main housing2102. In some embodiments, the mating surface4120is located at the end of the sidewall of the main housing2102and is oriented perpendicular to the axis of the main housing2102(i.e., perpendicular to the insertion axis of the sensor cap2108). This abutment between the shoulder of the sensor cap2114and the main housing2102is advantageous because it helps to ensure correct positioning of the sensor cap2114within the main housing2102. In some embodiments, the moisture barrier seal between the main housing2102and the sensor cap2108is formed by welding these two structures together at the mating surface. This can be accomplished by providing, for example, a metal interlayer4130at the location of the mating surface4120. This metal interlayer4130can be formed or provided on or adjacent to either the main housing2102or the sensor cap2108at the location of the mating surface4120. For example, the metal interlayer4130can be a ring with an inner diameter equal to or larger than the diameter of the plug portion2115of the sensor cap2108and an outer diameter that is preferably smaller than the diameter of the head portion2114of the sensor cap2108. Then, a laser can be used to apply heat to the metal interlayer4130so as to melt it and fuse the main housing2102and the sensor cap2108together at the mating surface4120. The laser can have an operating wavelength which causes the laser to be substantially transparent to the material of the main housing2102and/or the sensor cap2108. For example, the main housing2102and/or the sensor cap2108may be made of silicon and the welding laser may have an operating wavelength (e.g., in the infrared spectrum) which is not substantially absorbed by the silicon. In this way, the laser light can pass through the structure of the main housing2102and/or the sensor cap2108until it impinges upon the metal interlayer4130, which absorbs, and is heated by, the laser light, causing the metal interlayer to form a welded interface between the main housing2102and the sensor cap2108. In some embodiments, light from the welding laser is applied through the head portion2114of the sensor cap2108toward the mating surface. Bi-Diameter Main Housing for IOP Sensing Implant FIG.42Ais a perspective view of an embodiment of an IOP sensing implant with a bi-diameter main housing4202.FIG.42Bis a side view of the bi-diameter main housing4202shown inFIG.42A. The bi-diameter main housing4202can be similar to other main housings described herein (e.g., the main housing2102shown inFIG.21and elsewhere) in that it can be an elongate tubular body designed to receive a tip cap (e.g.,2102) and a sensor cap (e.g.,2108) at opposite ends. The end which receives the tip cap will be referenced as the tip cap end, while the end which receives the sensor cap will be referenced as the sensor cap end. The bi-diameter main housing4202can have a first diameter at the tip cap end and a second, larger diameter at the sensor cap end. In some embodiments, the diameter of the sensor cap end may be at least 10%, and as much as 300%, larger than the diameter of the tip cap end. A shoulder4210can join the smaller-diameter (tip cap end) and the larger-diameter (sensor cap end) portions of the bi-diameter main housing4202. In some embodiments, the tip cap end of the main housing can have a constant first diameter, and the sensor cap end of the main housing can have a constant second, larger diameter, though this is not required. FIG.42Cillustrates a magnified view of the region around the shoulder4210of the bi-diameter main housing4202shown inFIGS.42A and42B. As shown inFIG.42C, in some embodiments, the shoulder4210can be a step transition between the smaller-diameter (tip cap end) and the larger-diameter (sensor cap end) portions of the bi-diameter main housing4202. In other words, the shoulder4210can be formed as one or more surfaces which join the smaller-diameter and the larger-diameter portions of the main housing4202and which are generally perpendicular to the axis of the elongate main housing4202. Alternatively, the shoulder can be a tapered transition between the smaller-diameter and the larger-diameter portions of the main housing. As already discussed herein, the IOP sensing implant can be sized and shaped for insertion into certain ocular anatomical structures, such as the supraciliary/suprachoroidal space. The bi-diameter design of the main housing4202can be advantageous in such embodiments because the shoulder4210can serve as a mechanical stop when inserting the IOP sensing implant (tip cap end first) into ocular tissue. This can help to ensure that the IOP sensing implant is properly positioned in the ocular tissue. For example, the shoulder4210of the bi-diameter main housing4202can help prevent over-insertion of the IOP sensing implant into the supraciliary/suprachoroidal space. This in turn helps to ensure that the sensor cap end at least partially extends into the anterior chamber of the eye so as to measure IOP in the anterior chamber. The distance from the shoulder4210to the furthest extent of the sensor cap end of the IOP sensing implant can correspond to the desired distance that the IOP sensing implant is to extend into the anterior chamber from the ocular tissue where the implant is anchored. Additional benefits of the bi-diameter design of the main housing4202include that the smaller diameter of the tip cap end helps to provide for easier insertion into ocular tissue, while the larger diameter of the sensor cap end can accommodate a larger IOP sensing module. WhileFIGS.42A-42Cillustrate a shoulder4210in the main housing4202which serves as a mechanical stop to prevent over-insertion of the IOP sensing implant in ocular tissue, other designs for mechanical stops are also possible. For example, the main housing could alternatively and/or additionally include one or more ridges, flanges, or other structures which project radially from the housing, and wholly or partially surround the circumference of the housing, so as to act as a mechanical stop when inserting the implant into ocular tissue. Cupped Sensor Cap Design FIG.43Ais a perspective view of a cupped sensor cap4308for an intraocular pressure sensing implant. In the illustrated embodiment, the sensor cap4308is implemented as a bi-diameter sensor cap which includes a plug portion4315that is designed to be inserted into the main housing (e.g.,2102,4202) of the implant and a head portion4314that extends from the plug portion4315. The IOP sensing module may be provided, for example, wholly in the head portion4314or partially in the head portion and partially in the plug portion4315. The head portion4314of the sensor cap4308has a concave shape in that it includes a depression4310formed in the outward-facing portion of the cap4308. The depression4310is formed in the central portion of the sensor cap and is surrounded by a peripheral wall4311. The IOP sensing module of the sensor cap can be formed in the depression4310so that it is surrounded by the peripheral wall4311. In some embodiments, the IOP sensing module includes a flexible diaphragm2111which is part of a pressure sensing module (e.g., a capacitive or piezoresistive pressure sensing module). As the flexible diaphragm2111may be delicate, its location in the depression4310of the sensor cap4308, surrounded by the peripheral wall4311, offers a measure of protection against damage when the implant is being handled or manipulated prior to, and during, surgical implantation. Other pressure sensing devices may also benefit from the physical protection offered by the cupped sensor cap design shown inFIG.43A. WhileFIG.43Aillustrates a bi-diameter sensor cap4308design, other types of housings can likewise include cupped regions (e.g., at a distal location) like the one illustrated inFIG.43A. FIG.43Bis another perspective view of the cupped sensor cap4308but from the opposite side of what is shown inFIG.43A. As is evident inFIG.43B, the sensor cap4308can, like other embodiments of sensor caps disclosed herein (e.g.,2108), include a cutout4316to physically connect with a carrier member (e.g.,2072) which has various electronic components mounted thereon. In addition, the sensor cap4308can include one or more electrical contacts4313to electrically connect the IOP sensing module located in the sensor cap4308with one or more other electrical components in the IOP sensing implant.FIG.43Cis yet another perspective view of the cupped sensor cap4308but this time as mounted in a tubular main body2102of the IOP sensor implant housing. Although the cupped design of the sensor cap4308inFIG.43Ais advantageous for its protective properties, it may also pose some complications which could affect the capability of the IOP sensing module—located in the depression4310of the sensor cap—to operate within the eye. For example, the depression4310in the sensor cap may have a tendency to trap an air pocket adjacent to the IOP sensing module when the implant is inserted into the eye. If an air pocket were to be trapped by the peripheral wall4311inside the depression4310, it could act as a barrier between the IOP sensing module and the aqueous humor. Although an air pocket may at least partially transmit pressure from the aqueous to the sensing module, it is also possible that an air pocket which fills, or partially fills, the depression4310may negatively impact the accuracy of IOP measurements due to forces generated by surface tension at the interfaces of the air pocket and aqueous and/or flexible diaphragm2111, or due to other effects such as affecting the parasitic capacitance acting on the IOP sensing module. This potential problem may be at least partially ameliorated by providing a hydrophilic coating on the inside of the depression4310of the sensor cap4308. For example, the inside of the peripheral wall4311may be coated with a hydrophilic material. Similarly, the flexible diaphragm2111located at the bottom of the depression4310may likewise be coated with a hydrophilic material. The presence of the hydrophilic material within the depression4310of the sensor cap may facilitate priming of the depression with aqueous humor. Examples of suitable hydrophilic materials include various oxides including silicon oxide, titanium oxide, tantalum oxide, etc., various nitrides including silicon nitride, titanium nitride, tantalum nitride, etc., various carbides including silicon carbide, titanium carbide, etc. Such materials may be deposited as a thin layer using atomic layer deposition (ALD), physical vapor deposition (PVD) methods such as sputtering or evaporation, or chemical vapor deposition (CVD), among other methods. Other materials may be applied as a thin film to create a hydrophilic surface including biomaterials such as heparin, poly-L-lysine, etc. Alternatively and/or additionally, the hydrophilicity of the hydrophilic surfaces of the inside of the peripheral wall4311and/or flexible diaphragm2111may be increased by increasing the surface roughness using a variety of means such as dry or wet chemical etching or physical etching such as ion bombardment. Such roughening may be performed before, after, or in place of coating with a hydrophilic material. Alternatively and/or additionally, the potential problem of the cupped region of the sensor cap4308failing to prime with aqueous humor can be reduced or eliminated by using a special delivery apparatus to surgically insert the implant. FIG.44illustrates an embodiment of a distal portion4400of a delivery apparatus for surgically inserting an IOP sensing implant having a cupped sensor cap. The delivery apparatus can include, for example, a handpiece, a holder, a delivery mechanism, a plunger, etc., as described elsewhere herein. The distal portion4400of the delivery apparatus is the portion of the delivery apparatus which is in contact with the IOP sensing implant during surgical implantation. In some embodiments, the distal portion4400of the delivery apparatus is a plunger tip. The plunger tip can include, for example, a main body4405and a projection4410which is used to engage the concave portion of the sensor cap4308. The projection4410can be the physical complement of the depression4310formed in the sensor cap4308. In the illustrated embodiment, the projection4410has a diameter which is no larger than the diameter of the depression4310in the sensor cap4308, while the main body4405of the distal portion4400of the delivery apparatus has a diameter which is larger than that of the depression4310in the sensor cap4308. This results in a shoulder where the projection4410is joined with the main body4405. The length of the projection4410from the main body4405may be, for example, less than or equal to the depth of the depression4310in the sensor cap4308. When the projection4410is inserted into the depression4310of the sensor cap4308, the shoulder may engage with the peripheral wall4311of the sensor cap. This engagement may prevent over insertion of the projection4410into the depression4310of the sensor cap4308, which could otherwise damage the IOP sensing module located in the depression. As discussed elsewhere herein, the delivery apparatus can be used to surgically insert the IOP sensing implant at the desired location within the eye. Once the IOP sensing implant is released from the delivery apparatus, the projection4410is withdrawn from the depression4310in the sensor cap4308. The withdrawal of the projection4410creates a vacuum which draws aqueous humor into the depression4310of the sensor cap4308, thereby priming the depression with fluid and reducing or eliminating the amount of air trapped in the depression of the sensor cap. In other embodiments, the depression4310of the sensor cap4308can be filled with a non-compressible, pressure-transmitting gel or other substance prior to insertion into the eye. The gel may displace air from the depression in the sensor cap. Further, once the IOP sensing implant is surgically implanted, the gel may act as a pressure-transmitting medium which can allow pressure to be exerted on the IOP sensing module (located in the depression of the sensor cap) by the aqueous humor in the eye. Examples of suitable materials for the non-compressible, pressure-transmitting gel include silicon gel, fluorosilicon gel, etc. Sealing and Sterilizing an IOP Sensing Implant Various embodiments of the IOP sensing implants disclosed herein include a housing made up of an elongate, tubular main body (e.g.,2102,4202), a sensor cap (e.g.,2108,4308), and a tip cap (e.g.,2104). As discussed elsewhere, these various parts of the IOP sensing implant housing (or other parts of another embodiment of an IOP sensing implant housing) can be assembled and hermetic seals can be provided at the junctions between the various parts so as to prevent fluid from entering the housing after it has been implanted into the eye. Notwithstanding the fact that the IOP sensing implant housing may be hermetically sealed, it nevertheless may be advantageous to sterilize the interior of the implant. Sterilization could potentially be accomplished by heating the implant to a temperature that is sufficient to kill or deactivate bacteria, viruses, etc. However, the electronic components of the IOP sensing implant may not be able to withstand such temperatures. Therefore, it may be more advantageous to perform sterilization using, for example, a sterilization agent, such as a disinfectant gas. However, this technique, too, could pose technical challenges because of difficulty in assembling, bonding, and/or sealing the various parts of the IOP sensing implant housing while concurrently injecting and evacuating the sterilization agent, or alternatively sterilizing the various parts of the IOP sensing implant, including internal parts, prior to assembling, bonding and/or sealing the parts under aseptic conditions. Thus,FIGS.45and46illustrate a technique for advantageously separating the assembling, bonding, and/or sealing step(s) from the sterilization step(s) during the manufacturing process. FIG.45illustrates an example embodiment of a tip cap4504that can be used to facilitate sterilization of an IOP sensing implant. Meanwhile,FIG.46illustrates an example method4600for assembling, bonding, sealing, and sterilizing the IOP sensing implant. The method begins at block4610by providing the various parts of the IOP sensor implant housing. As discussed elsewhere herein, the various parts of the implant housing can include, for example, an elongate tubular main body, a sensor cap, and a tip cap. These housing parts can be as described elsewhere herein, with the exception that an injection port can be provided in at least one of the housing parts so as to facilitate the injection of a sterilization agent at a later time after the housing parts have been assembled, bonded, and/or hermetically sealed. FIG.45, for example, illustrates a tip cap4504which includes an injection port4534to facilitate injection of a sterilization agent after the IOP sensing implant housing has been assembled, bonded, and/or hermetically sealed. The tip cap4504includes a plug portion4532that is inserted into the tubular main body of the implant housing. The diameter of the plug portion4532corresponds to the inner diameter of the main body. In addition, the illustrated tip cap4504includes a head portion4530which extends from the tubular main body of the implant housing when the tip cap is inserted into the main body. As discussed elsewhere, the head portion4530of the tip cap can be rounded and/or pointed so as to facilitate insertion of the implant housing into ocular tissue. The injection port4534is a passageway (shown inFIG.45with dotted lines) that extends from an exterior location, through the tip cap4504, and into the tubular main body of the implant housing when the tip cap and the main body are assembled. At block4630of the method4600shown inFIG.46, the injection port4534in the tip cap4504can be used to introduce a sterilization agent, such as ethylene oxide or hydrogen peroxide, into the assembled IOP sensing implant housing. The sterilization agent can also be evacuated through the same port. Alternatively, multiple ports can be provided for injection and/or evacuation of the sterilization agent. These can be provided all in the same housing part or in different housing parts. The fact that sterilization can be performed after the various parts of the IOP sensing implant housing have already been assembled, bonded, and/or hermetically sealed his advantageous because it simplifies both the assembly procedure and the sterilization procedure since they need not necessarily be performed concurrently. At block4640an inert gas can optionally be injected into the assembled IOP sensing implant housing. For example, argon gas can be injected into the implant housing. The inert gas can advantageously extend the life of the battery inside the implant housing in the case that the battery includes lithium, which would otherwise be very reactive with the atmosphere inside the implant housing. Finally, at block4650, the injection port4534in the tip cap4504can be sealed. This can be accomplished in a variety of ways, including, for example, by melting the tip cap material surrounding the port (with laser energy, for example), by inserting a wire or plug (and optionally melting the wire or plug to seal the injection port), etc. Although the sterilization technique has been described with respect to an injection port provided in the tip cap4504, in other embodiments the injection ports may be provided in the sensor cap, in the tubular main body, or in any other housing part(s). IOP Sensing Implant with Flow-Enabling Features Various embodiments of the IOP sensor implants disclosed herein can be designed to be inserted/implanted/anchored at or in a physiological outflow pathway of the eye. In healthy eyes, these outflow pathways, such as Schlemm's canal (via the trabecular meshwork) or the uveoscleral outflow pathway, drain aqueous humor from the anterior chamber to prevent IOP from exceeding healthy levels. FIGS.47A-47Cillustrates embodiments of an IOP sensor implant housing with flow-enabling features. The flow-enabling features can enhance outflow of the aqueous, thereby reducing IOP levels. The flow enabling features may be, for example, external features of the IOP sensor implant housing which are not enclosed by the housing. Alternatively, and/or additionally, the flow enabling features may be at least partially enclosed by the IOP sensor implant housing. FIG.47Ais a perspective view of an example IOP sensor implant housing main body4702awith enclosed flow-enabling features.FIG.47Bis a cross-sectional view of the IOP sensor housing main body4702ashown inFIG.47A. The housing main body4702acan include a central main cavity4701to accommodate electrical components of the IOP sensor implant, as discussed elsewhere herein. In addition, the housing main body4702acan also include one or more flow pathways4703a. The flow pathways4703amay have, for example, a smaller diameter than the central cavity4701. In the embodiment illustrated inFIG.47B, the housing main body4702aincludes two flow pathways4703aon opposing sides of the central cavity4701. Each of these flow pathways4703can be, for example, an enclosed lumen running substantially the entire axial length of the main body4702aof the IOP sensor implant housing. When the housing is surgically implanted in, for example, a physiological outflow pathway of the eye, one end of each flow pathway4703acan be located in the anterior chamber, while the opposite end of each flow pathway can be located in the physiological outflow pathway. The flow pathways can enhance drainage by conducting aqueous out of the anterior chamber. As shown inFIG.47B, the enclosed flow pathways4703agive the main body4702of the implant housing a widened shape in the direction of the transverse axis. The flow pathways4703acan advantageously occupy gaps that may otherwise exist between layers of tissue when inserting the implant in, for example, the supraciliary/suprachoroidal space. FIG.47Cis a perspective view of an example IOP sensor implant housing main body4702bwith open, external flow-enabling features. Once again, the housing main body4702bcan include a central main cavity4701to accommodate electrical components of the IOP sensor implant. In addition, the housing main body4702bcan include one or more open, external flow-enabling features. In the illustrated embodiment, the open, external flow-enabling features are one or more ribs4703b, or alternatively grooves/channels, which run substantially the entire axial length of the main body4702bof the IOP sensor implant housing. The ribs4703can be in contact with eye tissue and aqueous can flow along the grooves/channels. Again, when the housing4702bis surgically implanted in, for example, a physiological outflow pathway of the eye, one end of each flow-enabling feature4703bcan be located in the anterior chamber, while the opposite end of each flow-enabling feature can be located in the physiological outflow pathway. In this way, drainage can be enhanced. In some embodiments, external flow-enabling features can be made out of or include a porous material, such as fritted glass, porous plastic such as polypropylene, polyethylene, etc., porous bonded polymer fibers such as polyethylene, polyester, etc. or other materials that are preferably hydrophilic and can be formed into an open-cell porous structure. Such porous materials provide a plurality of fluid handling capillary or pseudo-capillary structures that enable fluid transfer through the bulk structure of the material itself. For example, the porous material may be provided on substantially the entire exterior surface of the housing, in axial ribs or strips on the housing, in grooves/channels formed on the outside of the housing (e.g., between the ribs4703bshown inFIG.47C), etc. Intraocular Pressure Sensing Implant with Anchoring Tacks FIGS.48A and48Billustrate an example embodiment of an anchoring system for attaching an intraocular implant to eye tissue. This anchoring system can be used to attach IOP sensing implants like those described herein (e.g., IOP sensing implant2102) to tissue and/or anatomical structures inside the eye (e.g., in the anterior chamber). The anchoring system may include one, two, or more anchoring tethers4802. As shown in the figures, a first portion of each anchoring tether can be designed to attach to the intraocular implant that is to be anchored down, while a second portion of each anchoring tether can be designed to attach to an anchoring tack which is inserted into eye tissue. The anchoring tacks can be functional beyond simply serving as anchors in ocular tissue. For example, the anchoring tacks can also be implant devices which perform one or more functions which are complementary to, and/or in addition to, the function(s) performed by the intraocular implant that is being anchored to the eye tissue by the anchoring tacks. In the embodiment illustrated inFIG.48A, the anchoring system includes a first anchoring tether4802alocated at the tip end of the IOP sensing implant2102and a second anchoring tether4802blocated at the sensor end, though other embodiments could include a different number of anchoring tethers. It should be understood that while IOP sensing implant2102is shown in these figures, the illustrated anchoring tethers4802can be used on other designs of an IOP sensing implant and other types of implants as well. The anchoring tethers4802can be made of, for example, flexible wires or cords. Nitinol is a possible material due to its super-elasticity and biocompatibility. Also, thin wires or other loop structures made of titanium, gold, or stainless steel are also possible. Non-metallic cords made of nylon, polyester, polyvinylidene fluoride, polypropylene, etc. may also be used in some embodiments. Each anchoring tether4802can be attached to the IOP sensing implant2102. This can be done by, for example, providing an attachment loop portion4803which wraps around the housing of the IOP sensing implant. The housing of the IOP sensing implant may in turn include one or more circumferential ridges, flanges, or troughs, and/or one or more hooks, eyelets, etc. so as to help position the attachment loop portions4803and/or hold the attachment loop portions in place with respect to the IOP sensing implant housing. As illustrated inFIG.48A, in some embodiments the attachment loop portion4803of each anchoring tether can azimuthally wrap around the circumference of the implant body in a plane that is perpendicular to the axis of the implant body. The anchoring tethers4802can also each include an anchor loop portion4804which extends from the attachment loop portion4803at one or more connection points to form a loop which can receive an anchoring tack. In some embodiments the anchoring loop portion4804of each anchoring tether4802can extend from the attachment loop portion4803in a plane that is parallel with the axis of the implant body. In other words, the attachment loop portion4003and the anchoring loop portion4804of each anchoring tether4002can be oriented generally in planes that are orthogonal to one another. In other embodiments, an anchoring tether could be attached to the implant in different ways, such as by welding or brazing the tether to the housing, by use of adhesives such as epoxy, or by providing an eyelet or similar structure in the housing through which the anchoring tether can loop through, for example. FIG.48Aillustrates two example embodiments of anchoring tacks4810a,4810b. The first example anchoring tack4810ais a drug eluting intraocular implant. This implant can be similar to, for example, the one illustrated in FIG. 18 of U.S. Patent Publication 2015/0342875 (see accompanying appendix), filed May 28, 2015, and entitled “IMPLANTS WITH CONTROLLED DRUG DELIVERY FEATURES AND METHODS OF USING SAME,” the entire contents of which are hereby incorporated by reference herein. The second example anchoring tack4810bis a drainage stent which enhances outflow of aqueous humor from the eye. This implant can be similar to, for example, the one illustrated in FIG. 18 of U.S. Pat. No. 9,554,940 (see accompanying appendix), filed Mar. 14, 2013, and entitled “SYSTEM AND METHOD FOR DELIVERING MULTIPLE OCULAR IMPLANTS,” the entire contents of which are hereby incorporated by reference herein. Each of the anchoring tacks4810a,4810bcan include a penetrating tip which is designed to penetrate ocular tissue, such as the sclera, the trabecular meshwork, etc., and remain anchored therein after having been inserted. The penetrating tip of each anchoring tack4810can be inserted through the respective anchoring loop portion4804of the anchoring tethers4802, as illustrated by the arrows inFIG.48A. The body portions of the anchoring tacks4810can include one or more structural features designed such that the anchoring loop portions4804of the anchoring tethers4802are firmly retained once the tacks are inserted through the anchoring loop portions4804. For example, the body portions of the anchoring tacks4810can include one or more features (e.g., ridges, projections, flanges, etc.) which prevent the anchoring loop portions4804of the anchoring tethers4802from passing over the anchoring tacks once the anchoring tacks are inserted through the loops. For example, the feature(s) on the body portion of an anchoring tack4810can have at least one dimension that is larger than the diameter of the anchoring loop portion4804. Thus, the anchoring loop portions4804of the anchoring tacks4810can be firmly held between ocular tissue and the body portions of the anchoring tacks4810. FIG.48Billustrates an intraocular implant anchored inside the eye using the anchoring system shown inFIG.48A. AlthoughFIG.48Billustrates one example placement of the IOP sensing implant2102using the anchoring tethers4802, the illustrated anchoring system can also be used to attach various types of intraocular implants to various other locations within the eye. Sealed Battery with Through-Substrate Via Interconnects FIG.49Aillustrates a sealed thin-film battery4910mounted on a substrate4902and electrically connected to other components by through-substrate vias4904. The sealed thin-film battery4910may be, for example, a thin-film lithium-ion battery. Thin-film lithium-ion batteries can be advantageous because of their relatively high power density. But they can include very reactive materials and therefore should be well-sealed in order to provide a long-lasting useful lifetime. In some embodiments, the substrate4902upon which the thin-film battery4910is mounted is the carrier member572described elsewhere herein. As such, the substrate4902may be provided in an IOP sensing implant, as described herein. The battery4910may be electrically connected to other electrical components of an IOP sensing implant (e.g., controller, memory, IOP sensing module, etc.) by way of the through-substrate vias4904. In some embodiments, the substrate4902is made of glass, though it can also be made at least partially of other electrically insulating materials. The through-substrate vias4904are formed in the substrate4902on the side of the substrate upon which the battery4910is mounted. The vias4904include conductive structures or terminals (e.g., posts) which are oriented perpendicularly with respect to the bottom surface of the battery4910and are used to make electrical connections to the battery. The battery4910can be mounted, or fabricated in situ, flush with the surface of the substrate4902over the vias4904. As discussed further herein, this advantageously allows the physical interface between the battery4910and the substrate to be completely sealed. In some embodiments, the vias4904span the entire thickness of the substrate4902. In such embodiments, the vias404may allow the battery4910to be electrically connected with one or more conductive traces which are formed on the opposite side of the substrate from which the battery4910is mounted. In other embodiments, the vias4904may only partially span the thickness of the substrate. In such embodiments, the vias4904may allow the battery4910to be electrically connected with one or more conductive traces which are embedded in the substrate. FIG.49Bis a schematic cross-sectional view of an embodiment of the sealed thin-film lithium-ion battery4910mounted on the substrate4902. The thin-film battery4910can be made up of several electrically-active layers4916,4918,4920, and4922. For example, the thin-film battery4910can include a cathode current collector layer, a cathode layer, an electrolyte layer, and an anode current collector layer, depicted as layers4922,4920,4918, and4916, respectively, inFIG.49B. As shown in the drawing, the electrically-active layers may have somewhat different sizes, such that the peripheral edges of one layer may extend out from beyond another layer when they are provided in a stacked configuration. In other embodiments of thin-film batteries, different layers and/or layer configurations may be utilized beyond the ones illustrated inFIG.49B. For example, an anode layer may be included between the electrolyte layer and the anode current collector. In some embodiments, the anode layer is created during fabrication of the thin-film battery, while in other embodiments the anode layer is formed during the first instance of charging the battery. In some embodiments, the anode is Lithium metal. In a “Li-free” design, the anode can be plated onto the anode current collector during the charging of the battery. During discharge, the Li metal can be de-plated. After the first charge of the battery some Li metal may remain on the anode current collector even after battery discharge. In other embodiments, the Li anode can be deposited as part of the battery fabrication process and may be present even before first charge. The battery4910can be fabricated on the substrate itself (in situ). It can be produced in a batch process in a wafer format. The substrate can be made from the wafer material by cutting/releasing the individual substrates from the wafer after battery fabrication is complete. The electrically-conductive terminals of the thin-film battery4910are located at the bottom layer of the stack of electrically-active layers4916,4918,4920, and4922. These terminals make electrical connection to the through-substrate vias4904that are formed in the substrate4902upon which the thin-film battery4910is mounted (or fabricated in situ). In this way, the stack of electrically-active layers of the thin-film battery4910can be flush with the mounting surface of the substrate4902. FIG.49Balso illustrates an insulating layer4914which is formed over the stack of electrically-active layers4916,4918,4920, and4922. As shown in the drawing, the insulating layer4914can be formed not only over the surface of the top layer of the stack of electrically-active layers4916,4918,4920, and4922, but also over any portions of the layers in the stack which may extend beyond the layers above. The insulating layer may extend to the mounting surface of the substrate4902around the entire perimeter of the battery4910. The insulating layer4914can be made of, for example, any suitable electrically-insulating material, such as a polymer. Additionally,FIG.49Bshows a sealing layer4912which is formed over the insulating layer4914. In some embodiments, the sealing layer is an impermeable metal barrier layer which prevents atoms or molecules outside the battery4910from interacting with atoms or molecules inside the battery, and vice versa. The sealing layer may extend to the mounting surface of the substrate4902around the entire perimeter of the battery4910, including the perimeter of the insulating layer4914. Since the through-substrate via interconnects allow the thin-film battery4910to sit flush on the surface of the substrate4902, the sealing layer4912can be provided or formed without gaps between the substrate4902and the sealing layer4912. Thus, the illustrated battery architecture offers improved sealing performance which in turn improves the useful lifetime of the battery4910without requiring more complex sealing structures or techniques, specifically by not requiring lateral feedthroughs or interconnects that must transit the sealing layer4912. FIGS.49C-49Eare top views which further illustrate the architecture of the thin-film battery4910.FIG.49Cis a top view of the stack of electrically-active layers4916,4918,4920,4922of the thin-film battery4910. As illustrated, the stack of electrically-active layers is provided on the substrate4902and a through-substrate via4904(shown in phantom line) is provided under the stack.FIG.49Dshows the insulating layer4914provided over the stack of electrically-active layers4916,4918,4920,4922. As illustrated, the insulating layer4914extends all the way to the substrate4902, both in its lateral and longitudinal extent.FIG.49Eshows the metal sealing layer4912provided over the insulating layer4914. The insulating layer4914serves to separate the metal sealing layer4912from the electrically-active layers4916,4918,4920,4922. As illustrated inFIG.49E, the metal sealing layer4912extends all the way to the substrate4902, both in its lateral and longitudinal extent, completely covering the insulating layer4914and leaving no gaps between the sealing layer4912and of the substrate4902. The fact that there are no electrical interconnect structures which extend laterally outward from the battery4910on or over the mounting surface of the substrate4902means that the quality of the seal between the sealing layer4912and the substrate4902is enhanced. This is in contrast to the configuration shown inFIG.49F. FIG.49Fillustrates a thin-film battery architecture which includes a lateral electrical interconnect rather than a through-substrate via electrical interconnect. As illustrated, the lateral electrical interconnect extends laterally from the battery on the mounting side of the substrate. As a result of the lateral electrical interconnect, the battery shown inFIG.49Fis likely to have a less effective seal between the sealing layer4912and the substrate4902. This is because the sealing layer4912can extend completely down to the substrate on the sides of the lateral electrical interconnect but then must rise over the top of the lateral electrical interconnect, which extends from the battery underneath the sealing layer4912. This can result in the formation of a gas diffusion pathway through the insulating layer4914between the sealing layer4912and the substrate, which in turn can allow materials inside the battery to react with gases and water vapor entering the battery structure from the outside environment, therefore reducing the useful lifetime of the battery. Stacked IC and Battery Structure FIG.50illustrates a compact stacked integrated circuit and battery structure for an intraocular implant. This compact structure is advantageous because intraocular implants, such as IOP sensing implants, are typically quite small in size and therefore space inside the implant is limited. The illustrated stacked structure includes a substrate5002, which, in some embodiments, is the carrier member572described elsewhere herein. As such, the substrate5002may be provided in an IOP sensing implant, as described herein. A first battery5010is mounted to the top of the substrate5002and a second battery5010is mounted to the bottom of the substrate. The batteries5010may be mounted to the substrate5002by way of through-substrate vias5004, as described with respect toFIGS.49A and49B. In some embodiments, the first and second batteries each have a thickness of less than 50 μm. For example, the first and second batteries may each have a thickness of approximately 30μ or less. A first integrated circuit5012is mounted to the top surface of the substrate5002over, and spanning, the first battery5010which is likewise mounted on the top surface of the substrate. Although not illustrated, the structure could also include a second integrated circuit mounted to the bottom surface of the substrate5002over, and spanning, the second battery5010. The first integrated circuit5012is electrically connected to one or more conductive traces5014on the substrate5002by way of one or more solder bumps5013. The solder bumps have at least one dimension (e.g. a height) which is greater than the thickness of the battery5010over which the integrated circuit is mounted. For example, in some embodiments, the solder bumps have a height of 50 μm or more. The lateral dimensions of the integrated circuit are greater than those of the battery5010over which the integrated circuit is mounted. Thus, the integrated circuit5012can span the battery5010and can be supported by solder bumps5013located around the periphery of the integrated circuit beyond the lateral extent of the battery5010. Since the height of the solder bumps5013can be greater than the thickness of the battery5010, the battery can occupy the space underneath the integrated circuit which otherwise would not have been occupied by any component and would instead have been wasted. In other embodiments, the solder bumps can be replaced by stud bumps, such as gold stud bumps. Stud bumps may be used in conjunction with conductive epoxy to perform the same function as the solder bumps, but they can be smaller and can be processed at lower temperatures. Although a battery5010is illustrated as being mounted on the substrate5002below the integrated circuit5012, in other embodiments some other electrical component could be mounted under the integrated circuit. However, this mounting location is particularly suited for a thin-film battery due to its relatively small thickness in comparison to the size of the solder bumps5013which are used to connect the integrated circuit to the substrate5002. Similarly, although an integrated circuit5012is illustrated as being connected and mounted by one or more solder bumps, in other embodiments some other electrical component could be mounted over the battery5010using solder bumps, such as an additional battery. Antenna for Intraocular Implant Various embodiments of the intraocular implants described herein can include a transceiver module (and/or other wireless interface) and an antenna for wirelessly communicating with one or more external devices. The antenna can also be used for receiving power from an external device via inductive coupling. Any antenna that is used will have a natural or self-resonant frequency which is dependent upon the associated inductance and capacitance of the antenna design. The natural or self-resonant frequency is the frequency of electromagnetic radiation to which the antenna is most sensitive. Therefore, it is advantageous that there be a relative match between the self-resonant frequency of the antenna and the operating frequency of the transceiver module or other wireless interface used by the intraocular implant. FIG.24illustrates an example coil antenna2085which consists of loops of wire which spiral around the internal components of the intraocular implant as the coil antenna extends along the longitudinal axis of the implant housing. It is not unusual that this type of antenna design may have a self-resonant frequency of several hundred megahertz or that it even extend into the gigahertz range. These frequencies are typically much higher than the operating frequency of the transceiver module or other wireless interface used by the intraocular implant. Accordingly, it may be necessary to use additional circuit elements, such as a capacitor and/or an inductor, to tune the antenna so that it is more sensitive to the operating frequency of the transceiver module or other wireless interface. One disadvantage associated with this approach is that such circuit elements may occupy valuable space within the intraocular implant. If the antenna could be tuned in another manner without requiring the use of additional circuit elements, or if the antenna could be designed such that its self-resonant frequency naturally corresponded to the operating frequency of the transceiver module or other wireless interface, then the size of the intraocular implant could advantageously be reduced. FIG.51Aschematically illustrates cross-sectional views of three example coil antennas which may be used in an intraocular implant. The black dots represent cross-sections of coils of wire. Meanwhile, the arrows represent the magnetic field induced by the current flowing through the coils of wire.FIG.51Bis a photograph of example embodiments of the three coil antenna designs shown inFIG.51A. The left-hand, middle, and right-hand coil antennas inFIG.51Arespectively correspond to the top, middle, and bottom coil antennas inFIG.51B. The coil antenna design on the left inFIG.51Ais one in which the wire turns are spaced apart from one another along the longitudinal axis of the coil antenna. In addition, in the left-hand coil antenna design, there is only one layer (in the radial direction) of wire turns. The loops formed by the turns of wire result in an amount of inductance which impacts the self-resonant frequency of the antenna. In addition, the proximity of the turns of wire, as determined by the spacing between adjacent turns, results in some amount of parasitic capacitance which also impacts the self-resonant frequency of the antenna. As shown inFIG.51B, this coil antenna design may typically have a self-resonant frequency of about 1.2 GHz. The coil antenna design in the middle ofFIG.51Ais similar to the left-hand coil design except that the turns of wire are touching one another in the middle coil antenna design. The wire is tightly wrapped along the longitudinal axis of the coil antenna such that each turn of wire is in contact with the adjacent turn of wire in the longitudinal direction. (The wire may be coated with a thin insulator to allow the turns of wire to be in contact with one another without shorting out the coil.) The middle coil antenna design has certain advantages over the left-hand coil antenna design. These advantages include that a greater number of turns of wire can fit into a given longitudinal space because they are not spaced apart from one another. This can increase the self-inductance of the antenna and improve the inductive coupling performance of the coil antenna for purposes of, for example, wireless power transfer. In addition, the lack of separation between adjacent turns of wire increases the parasitic capacitance of the coil antenna. The increased parasitic capacitance and the increased self-inductance lower the self-resonant frequency of this coil antenna design. For example, as shown inFIG.51B, this coil antenna design may typically have a self-resonant frequency of about 500 MHz. This reduction in self-resonant frequency, as compared to the coil antenna with spaced apart wire turns, is advantageous because it can be tuned to the operating frequency of the transceiver module or other wireless interface using smaller capacitor and/or inductor circuit elements. The coil antenna design on the right-hand side inFIG.51Ais distinct from the middle coil antenna design in that it includes two (or more) layers of wire turns (in the radial direction). As indicated by the blue arrows, the wire turns are wrapped such that the electrical current through the first and second layers of wire turns flows in the same direction. As illustrated, in this design each turn of wire is now not only in contact with the adjacent turn in the longitudinal direction but it is also in contact with one or more adjacent turns in the radial direction. The close proximity of each turn of wire to multiple other turns of wire greatly increases the parasitic capacitance of the right-hand coil antenna design. This in turn greatly reduces the self-resonant frequency of the coil antenna. For example, as shown inFIG.51B, this coil antenna design may typically have a self-resonant frequency of about 47 MHz. Although the coil antenna design shown on the right-hand side ofFIG.51Atakes up more space in the radial direction because it has multiple layers of wire turns, which correspondingly either reduces the amount of space available for other components to be housed inside the coil or requires an increase in the size of the housing of the intraocular implant, it turns out that any drawbacks associated with this increase in the radial thickness of the coil antenna is more than compensated by the reduction in the self-resonant frequency of the antenna. The reduction in the self-resonant frequency means that the capacitor and/or inductor circuit elements which may otherwise be required so as to tune the antenna to the operating frequency of the transceiver module and/or other wireless interface can be reduced in size or even completely eliminated. The coil antenna design shown on the right-hand side ofFIG.51Aalso has an additional advantage which is illustrated inFIG.51C. FIG.51Cillustrates the electromagnetic shielding effect offered by the two-layer coil antenna design shown inFIG.51A. As already discussed previously herein, a carrier member with one or more electrical components can be provided in the open space in the interior of the coil antenna. The left-hand side ofFIG.51Cshows an integrated circuit component provided in the interior space of a coil antenna with a single layer of spaced apart wire turns (i.e., as in the left-hand side ofFIG.51A). Rays of electromagnetic radiation (e.g., background electromagnetic radiation in the environment) are incident upon the transverse side of the coil antenna. The electromagnetic radiation can penetrate the coil antenna due to the spacing between the coil turns. This electromagnetic radiation can then be incident upon the integrated circuit, causing electromagnetic interference which may be detrimental to the operation of the integrated circuit, particularly if low-power subthreshold transistors are used. In contrast, as shown on the right-hand side ofFIG.51C, the coil antenna with two or more layers of wire turns which are tightly wrapped, and touching one another, in the longitudinal direction is much more effective at shielding the interior integrated circuit from electromagnetic radiation. Antenna for Intraocular Implant Having Bi-Diameter Main Housing FIG.52Aillustrates the location of an antenna5285inside an embodiment of an intraocular implant with a bi-diameter main housing5202. The bi-diameter main housing5202of the intraocular implant is described herein with respect toFIG.42A. It has a first, larger diameter at the sensor cap end of the bi-diameter main housing5202and a second, smaller diameter at the tip cap end. As shown inFIG.52A, a coil antenna5285, such as the one illustrated on the right-hand side ofFIG.51A, can be provided at least partially in the sensor cap end of the bi-diameter main housing. This arrangement has multiple advantages. First, the diameter of the coil antenna can be made larger than if the antenna were provided in the smaller-diameter portion of the bi-diameter main housing. This increases the amount of electromagnetic flux which can pass through the coil during inductive power transfer from external device. Another advantage is illustrated inFIG.52B. FIG.52Bshows the intraocular implant ofFIG.52Aimplanted in the eye of a patient. In this embodiment, the intraocular implant is anchored in, for example, the suprachoroidal/superciliary space of the patient's eye. The left-hand side ofFIG.52Bshows a coil antenna5284that is narrower and longer than the coil antenna5285shown inFIG.52Adue to its being provided in the smaller-diameter portion of the bi-diameter housing5202. The charging coil5286of an external power device is also illustrated. The charging coil5286of the external power device is brought in proximity to the patient's eye so as to inductively couple with the coil antenna5284. The distal end of the coil antenna5284contributes less to the inductive power transfer than does the proximal end because it is located further away from the charging coil5286of the external power device. Thus, it would be advantageous if a greater portion of the coil antenna inside the intraocular implant could be positioned nearer the charging coil of the external device when the implant is installed at the desired location within the eye. As shown in the right-hand side ofFIG.52B, this aim is achieved by the configuration shown inFIG.52A. When the coil antenna5285is provided in the larger-diameter sensor cap end of the intraocular implant, a larger percentage of the coil is located nearer the charging coil5286of the external power device when the intraocular implant is installed at the desired location within the patient's eye. This improves inductive coupling between the antenna5285and the charging coil5286, thus improving wireless power transfer to the intraocular implant. IOP Sensing System Devices FIG.53is a table which describes several devices and systems which can be used in conjunction with the intraocular implants described herein. A physician diagnostic device can be used by a physician to download data (e.g., IOP measurements), wirelessly re-charge a patient's IOP sensing implant, perform implant system diagnostics, re-program the implant, etc. The physician diagnostic device may take the form of a pair of glasses, a soft mask, etc. An atmospheric pressure monitor device may be a patient-worn device which measures and records local atmospheric pressure readings which can be used together with readings from the implant to determine IOP gauge pressure values. This device may take the form of a wrist band, watch, pendant, smartphone application, etc. A patient device can be used to download absolute IOP measurements from the implant, re-sync timers and/or re-charge super capacitor power sources on the implant. The device can include a screen or other output device to provide information (IOP readouts, battery life, etc.) and reminders (to re-sync timers, re-charge super capacitors, etc.). This device can be combined with the atmospheric pressure monitor device in some embodiments. A patient at-home recharge device can be worn by the patient for minutes or hours to recharge the intraocular implant's battery and/or supercapacitor, and/or to download data from the implant. This device may also allow increased functionality from the IOP sensing implant, such as taking and transmitting continuous IOP readings, that may otherwise consume too much power to perform when the IOP sensing implant is operating under battery power alone. This device may take the form of a pair of glasses, soft mask, etc. An at-home link-box can connect to other patient devices, such as those described above, to transfer data collected by them to a central server. It can also include a re-charging station to re-charge the external devices. A central server can be provided to receive patient data from multiple patients via the internet. The central server can process raw data to provide processed, adjusted, and/or corrected measurements. The central server can also provide a web-based interface for patients and physicians to view and/or download data. The foregoing devices may each communicate with one another via network connectivity, such as a wired or wireless network interface. Example Embodiments In some embodiments, an intraocular pressure (IOP) sensing system may comprise: an intraocular pressure sensing implant to be implanted into the eye of a patient for capturing absolute intraocular pressure measurements; and an external device for capturing atmospheric pressure measurements, wherein the intraocular pressure sensing implant is configured to capture an absolute intraocular pressure measurement at an appointed time, and wherein the external device is configured to capture a plurality of atmospheric pressure measurements around the appointed time. In any of the preceding embodiments, the intraocular pressure sensing implant may include a first onboard timekeeping device, and the absolute intraocular pressure sensing implant may be configured to capture the intraocular pressure measurement at the appointed time, as indicated by the first onboard timekeeping device. In any of the preceding embodiments, the external device may include a second timekeeping device, and the external device may be configured to capture the plurality of atmospheric pressure measurements around the appointed time, as indicated by the second timekeeping device. In any of the preceding embodiments, the external device may be configured to capture the plurality of atmospheric pressure measurements during a window of time which extends before and after the appointed time. In any of the preceding embodiments, the IOP sensing system may further comprise a processing device configured to analyze the plurality of atmospheric pressure measurements to determine a measure of the variation between the plurality of atmospheric pressure measurements. In any of the preceding embodiments, the processing device may be configured to determine whether the variation is within a predetermined range. In any of the preceding embodiments, the processing device may be configured to correlate one or more of the plurality of atmospheric pressure measurements with an absolute intraocular pressure measurement if the variation is within the predetermined range. In any of the preceding embodiments, the processing device may be configured to calculate a gauge intraocular pressure measurement from the correlated atmospheric pressure and absolute intraocular pressure measurements. In any of the preceding embodiments, the processing device may be separate from the external device. In any of the preceding embodiments, the external device may be configured to execute a synchronization operation by wirelessly transmitting synchronization information to the intraocular pressure sensing implant to aid in correlating one or more atmospheric pressure measurements with one or more absolute intraocular pressure measurements. In any of the preceding embodiments, the synchronization information may comprise a unique identification value or a timestamp. In any of the preceding embodiments, the external device may initiate the synchronization operation automatically at a predetermined time or interval. In any of the preceding embodiments, the external device may be configured to prompt the patient to initiate the synchronization operation. In any of the preceding embodiments, the prompt may comprise an audible alarm. In any of the preceding embodiments, initiating the synchronization operation may comprise positioning the external device within 12 inches of the patient's eye. In any of the preceding embodiments, the synchronization operation may comprise synchronizing a first timekeeping device onboard the intraocular pressure sensing implant with a second timekeeping device onboard the external device. In any of the preceding embodiments, the external device may be configured to be worn by the patient. In some embodiments, an intraocular pressure (IOP) sensing method may comprise: receiving an absolute intraocular pressure measurement from an intraocular pressure sensing implant implanted in the eye of a patient, the absolute intraocular pressure measurement having been captured at an appointed time; and receiving a plurality of atmospheric pressure measurements from an external device outside of the eye, the plurality of atmospheric pressure measurement having been captured around the appointed time. In any of the preceding embodiments, the absolute intraocular pressure measurement may be captured at the appointed time, as indicated by a first onboard timekeeping device included with the intraocular pressure sensing implant. In any of the preceding embodiments, the plurality of atmospheric pressure measurements may be captured around the appointed time, as indicated by a second timekeeping device included with the external device. In any of the preceding embodiments, the plurality of atmospheric pressure measurements may be captured during a window of time which extends before and after the appointed time. In any of the preceding embodiments, the IOP sensing method may further comprise analyzing the plurality of atmospheric pressure measurements to determine a measure of the variation between the plurality of atmospheric pressure measurements. In any of the preceding embodiments, the IOP sensing method may further comprise determining whether the variation is within a predetermined range. In any of the preceding embodiments, the IOP sensing method may further comprise correlating one or more of the plurality of atmospheric pressure measurements with the absolute intraocular pressure measurement if the variation is within the predetermined range. In any of the preceding embodiments, the IOP sensing method may further comprise calculating a gauge intraocular pressure measurement from the correlated atmospheric pressure and absolute intraocular pressure measurements. In any of the preceding embodiments, the IOP sensing method may further comprise analyzing the plurality of atmospheric pressure measurements using a processing device that is separate from the external device. In any of the preceding embodiments, the IOP sensing method may further comprise executing a synchronization operation by wirelessly transmitting synchronization information to the intraocular pressure sensing implant to aid in correlating one or more atmospheric pressure measurements with the absolute intraocular pressure measurement. In any of the preceding embodiments, the synchronization information may comprises a unique identification value or a timestamp. In any of the preceding embodiments, the IOP sensing method may further comprise initiating the synchronization operation automatically at a predetermined time or interval. In any of the preceding embodiments, the IOP sensing method may further comprise prompting the patient to initiate the synchronization operation. In any of the preceding embodiments, the prompt may comprises an audible alarm. In any of the preceding embodiments, initiating the synchronization operation may comprise positioning the external device within 12 inches of the patient's eye. In any of the preceding embodiments, the synchronization operation may comprise synchronizing a first timekeeping device onboard the intraocular pressure sensing implant with a second timekeeping device onboard the external device. In any of the preceding embodiments, the external device may be configured to be worn by the patient. In some embodiments, an intraocular pressure (IOP) sensing system may comprise: an intraocular pressure sensing implant to be implanted into the eye of a patient for capturing intraocular pressure measurements; and a temperature sensor for capturing temperature measurements, wherein the temperature measurements are used to at least partially compensate for the effect of temperature variations on the intraocular pressure sensing implant. In any of the preceding embodiments, the temperature sensor may be onboard the intraocular pressure sensing implant. In any of the preceding embodiments, the temperature sensor may be provided as part of an external device and the temperature measurements may be ambient temperature measurements. In any of the preceding embodiments, wherein the ambient temperature measurements may be used to estimate intraocular temperature values. In any of the preceding embodiments, he IOP sensing system may further comprise a processor to perform one or more operations to compensate for the effect of temperature variations on the intraocular pressure sensing implant. In any of the preceding embodiments, the processor may be configured to adjust the intraocular pressure measurements based on the temperature measurements. In any of the preceding embodiments, the processor may be configured to adjust measurement times corresponding to the intraocular pressure measurements based on the temperature measurements. In any of the preceding embodiments, the processor may be configured to exclude one or more intraocular pressure measurements based on the temperature measurements. In some embodiments, an intraocular pressure (IOP) sensing method may comprise: capturing intraocular pressure measurements using an intraocular pressure sensing implant implanted in the eye of a patient; capturing temperature measurements using a temperature sensor; and using the temperature measurements to at least partially compensate for the effect of temperature variations on the intraocular pressure sensing implant. In any of the preceding embodiments, the temperature sensor may be onboard the intraocular pressure sensing implant. In any of the preceding embodiments, the temperature sensor may be provided as part of an external device and the temperature measurements may be ambient temperature measurements. In any of the preceding embodiments, the ambient temperature measurements may be used to estimate intraocular temperature values. In any of the preceding embodiments, the IOP sensing method may further comprise performing one or more operations, using a processor, to compensate for the effect of temperature variations on the intraocular pressure sensing implant. In any of the preceding embodiments, the IOP sensing method may further comprise adjusting the intraocular pressure measurements based on the temperature measurements. In any of the preceding embodiments, the IOP sensing method may further comprise adjusting measurement times corresponding to the intraocular pressure measurements based on the temperature measurements. In any of the preceding embodiments, the IOP sensing method may further comprise excluding one or more intraocular pressure measurements based on the temperature measurements. In some embodiments, an intraocular pressure (IOP) sensing system may comprise: an IOP sensing implant configured to be implanted into a patient's eye, the IOP sensing implant including a supercapacitor for supplying at least a portion of operating power for the IOP sensing implant; and an external charging device configured to charge the IOP sensing implant, the external charging device including an output device for providing a prompt to the patient to carry out a charging interaction between the external device and the IOP sensing implant. In any of the preceding embodiments, the IOP sensing implant may further include a battery for supplying at least a portion of the operating power for the IOP sensing implant. In any of the preceding embodiments, the external charging device may be configured to output the prompt at charging interaction times, and the storage capacity of the supercapacitor may be greater than the expected energy usage of the IOP sensing implant between charging interaction times. In any of the preceding embodiments, the external charging device may be configured to output the prompt at charging interaction times, and the storage capacity of the supercapacitor may be less than the expected energy usage of the IOP sensing implant between charging interaction times. In any of the preceding embodiments, the storage capacity of the storage capacitor may be at least 0.01 μAh. In any of the preceding embodiments, the storage capacity of the storage capacitor may be at least 0.10 μAh. In any of the preceding embodiments, the storage capacity of the storage capacitor may be at least 1 μAh. In any of the preceding embodiments, the prompt to carry out the charging interaction may coincide with a prompt to synchronize a timekeeping device onboard the IOP sensing implant. In any of the preceding embodiments, the prompt to carry out the charging interaction may coincide with a prompt to download measurement data from the IOP sensing implant. In some embodiments, an intraocular pressure (IOP) sensing method may comprise: providing an IOP sensing implant configured to be implanted into a patient's eye, the IOP sensing implant including a supercapacitor for supplying at least a portion of operating power for the IOP sensing implant; charging the IOP sensing implant using an external charging device; and providing a prompt to the patient, using an output device included with the external charging device, to carry out a charging interaction between the external device and the IOP sensing implant. In any of the preceding embodiments, the IOP sensing implant may further include a battery for supplying at least a portion of the operating power for the IOP sensing implant. In any of the preceding embodiments, the IOP sensing method may further comprise outputting the prompt at charging interaction times, and the storage capacity of the supercapacitor may be greater than the expected energy usage of the IOP sensing implant between charging interaction times. In any of the preceding embodiments, the IOP sensing method may further comprise outputting the prompt at charging interaction times, and the storage capacity of the supercapacitor may be less than the expected energy usage of the IOP sensing implant between charging interaction times. In any of the preceding embodiments, the storage capacity of the storage capacitor may be at least 0.01 μAh. In any of the preceding embodiments, the storage capacity of the storage capacitor may be at least 0.10 μAh. In any of the preceding embodiments, the storage capacity of the storage capacitor may be at least 1 μAh. In any of the preceding embodiments, the prompt to carry out the charging interaction may coincide with a prompt to synchronize a timekeeping device onboard the IOP sensing implant. In any of the preceding embodiments, the prompt to carry out the charging interaction may coincide with a prompt to download measurement data from the IOP sensing implant. In some embodiments, an intraocular pressure sensor implant may comprise: a tubular main body; a bi-diameter sensor cap with a plug portion and a head portion, the diameter of the plug portion being smaller than the inner diameter of the tubular main body and the diameter of the head portion being larger than the inner diameter of the tubular main body, the sensor cap having a shoulder where the head portion and the plug portion meet; and a metal interlayer provided at a junction between the tubular main body and the shoulder of the sensor cap. In some embodiments, a method of manufacturing an intraocular pressure sensor implant may comprise: providing a tubular main body; providing a bi-diameter sensor cap with a plug portion and a head portion, the diameter of the plug portion corresponding to the inner diameter of the tubular main body and the diameter of the head portion being larger than the inner diameter of the tubular main body, the sensor cap having a shoulder where the head portion and the plug portion meet; providing a metal interlayer between the tubular main body and the shoulder of the sensor cap; inserting the plug portion of the sensor cap into the tubular main body until the shoulder abuts against the tubular main body; heating the metal interlayer until it melts, thereby fusing the tubular main body and the sensor cap. In any of the preceding embodiments, the method may further comprise heating the metal interlayer with a laser. In any of the preceding embodiments, the sensor cap may be formed of a material that is substantially transparent to the laser. In any of the preceding embodiments, the method may further comprise providing the metal interlayer as a pre-formed component of annular shape. In any of the preceding embodiments, the method may further comprise providing the metal interlayer on an end surface of the tubular main body. In any of the preceding embodiments, the method may further comprise providing the metal interlayer on the shoulder of the sensor cap. In any of the preceding embodiments, an intraocular pressure sensor implant may comprise: an intraocular pressure sensing module; and a tubular main body, the tubular main body including a first portion having a first diameter and a second portion having a second diameter which is larger than the first diameter. In any of the preceding embodiments, the implant may further include a tip cap inserted into the first portion of the tubular main body. In any of the preceding embodiments, the implant may further include a sensor cap inserted into the first portion of the tubular main body, the intraocular pressure sensing module being provided in the sensor cap. In any of the preceding embodiments, the tubular main body may be elongate. In any of the preceding embodiments, the tubular main body may be sized and shaped to be inserted into the supraciliary/suprachoroidal space of a human eye. In any of the preceding embodiments, the first portion and the second portion of the tubular main body may be joined by a shoulder. In any of the preceding embodiments, the shoulder may be a step transition between the first portion and the second portion of the tubular main body. In any of the preceding embodiments, the shoulder may be a tapered transition between the first portion and the second portion of the tubular main body. In some embodiments, a method for surgically implanting an intraocular pressure (IOP) sensing implant may comprise: providing the IOP sensing implant, wherein the IOP sensing implant includes an IOP sensing module and a tubular main body, the tubular main body including a first portion having a first diameter and a second portion having a second diameter which is larger than the first diameter; and inserting the IOP sensing implant into eye tissue such that the first portion of the tubular main body is located in the eye tissue and the second portion of the tubular main body extends from the eye tissue. In any of the preceding embodiments, the eye tissue may comprise the supraciliary/suprachoroidal space of a human eye. In any of the preceding embodiments, the first portion and the second portion of the tubular main body may be joined by a shoulder, and inserting the IOP sensing implant into eye tissue may comprise abutting the shoulder against the eye tissue. In some embodiments, an intraocular pressure sensor implant may comprise: an intraocular pressure sensing module; and a housing having a depression, the intraocular pressure sensing module being located in the depression. In any of the preceding embodiments, the intraocular pressure sensor implant may further comprise a peripheral wall surrounding the depression. In any of the preceding embodiments, the housing may include a tubular main body and a sensor cap configured to be inserted into an end of the tubular main body, and the intraocular pressure sensing module may be located in the sensor cap. In any of the preceding embodiments, a hydrophilic material may be provided in the depression. In any of the preceding embodiments, the intraocular pressure sensing module may include a flexible diaphragm. In any of the preceding embodiments, the intraocular pressure sensor implant may further comprise a non-compressible, pressure-transmitting gel provided in the depression. In some embodiments, a system for surgically implanting an intraocular pressure (IOP) sensing implant may comprise: an intraocular pressure sensing implant having an intraocular pressure sensing module and a housing with a depression, the intraocular pressure sensing module being located in the depression; and a delivery apparatus having a distal portion configured to engage the intraocular pressure sensing implant, the distal portion including a projection configured to mate with the depression in the housing of the intraocular pressure sensing implant. In any of the preceding embodiments, the depression in the intraocular pressure sensing implant and the projection of the distal portion of the delivery apparatus may be physical complements of one another. In any of the preceding embodiments, the length of the projection may be less than or equal to the depth of the depression. In any of the preceding embodiments, the diameter of the projection may be no greater than the diameter of the depression. In any of the preceding embodiments, the distal portion of the delivery apparatus may include a main body having a diameter that is greater than the diameter of the depression. In some embodiments, a method for surgically implanting an intraocular pressure (IOP) sensing implant may comprise: providing an intraocular pressure sensing implant having an intraocular pressure sensing module and a housing with a depression, the intraocular pressure sensing module being located in the depression; providing a delivery apparatus having a distal portion configured to engage the intraocular pressure sensing implant, the distal portion including a projection configured to mate with the depression in the housing of the intraocular pressure sensing implant; engaging the depression with the distal portion of the delivery apparatus; and inserting the intraocular pressure sensing implant into the eye of a patient using the delivery apparatus. In any of the preceding embodiments, the method may further comprise removing the distal portion of the delivery apparatus from the depression after inserting the intraocular pressure sensing implant into the eye of the patient. In any of the preceding embodiments, removing the distal portion of the delivery apparatus from the depression may cause aqueous humor in the eye to be drawn into the depression. In any of the preceding embodiments, the depression in the intraocular pressure sensing implant and the projection of the distal portion of the delivery apparatus may be physical complements of one another. In any of the preceding embodiments, the length of the projection may be less than or equal to the depth of the depression. In any of the preceding embodiments, the diameter of the projection may be no greater than the diameter of the depression. In any of the preceding embodiments, the distal portion of the delivery apparatus may include a main body having a diameter that is greater than the diameter of the depression. In some embodiments, an intraocular pressure sensor implant may comprise: an intraocular pressure sensing module; and a multi-part housing, at least one of the parts of the multi-part housing including an injection port to facilitate injection of a sterilization agent after the parts of the multi-part housing have been assembled. In any of the preceding embodiments, the multi-part housing may include at least a tubular main body and one or more caps configured to mate with the tubular main body. In any of the preceding embodiments, the injection port may be provided in a tip cap. In any of the preceding embodiments, the multi-part housing may include one or more connecting structures to join parts of the multi-part housing, and the injection port may be physically separate from the one or more connecting structures. In some embodiments, a method for sterilizing an intraocular pressure sensing implant may comprise: assembling at least a first housing part and a second housing part to form a housing of the intraocular pressure sensing implant, the housing comprising an intraocular pressure sensing module, and either the first housing part or the second housing part including an injection port; forming a hermetic seal at a junction between the first housing part and the second housing part; introducing a sterilization agent into the housing through the injection port; and sealing the injection port. In any of the preceding embodiments, the method may further comprise evacuating the sterilization agent from the housing before sealing the injection port. In any of the preceding embodiments, the method may further comprise introducing an inert gas into the housing through the injection port before sealing the injection port. In any of the preceding embodiments, sealing the injection port may comprise inserting a plug into the injection port. In any of the preceding embodiments, sealing the injection port may comprise applying heat to the injection port. In some embodiments, an intraocular implant may comprise: a housing; a main cavity in the housing with one or more components provided therein; and a first enclosed lumen extending from a first opening located at a first end of the housing to a second opening located at a second end of the housing. In any of the preceding embodiments, the first enclosed lumen may run the entire axial length of the housing. In any of the preceding embodiments, the one or more components provided in the main cavity may include one or more electrical components. In any of the preceding embodiments, the intraocular implant may further comprise a second enclosed lumen extending from a third opening located at the first end of the housing to a fourth opening located at the second end of the housing. In any of the preceding embodiments, the first enclosed lumen and the second enclosed lumen may be provided on opposite sides of the main cavity. In any of the preceding embodiments, the diameter of the first enclosed lumen and the diameter of the second enclosed lumen may be smaller than the diameter of the main cavity. In any of the preceding embodiments, the housing may taper in size from the main cavity to the first enclosed lumen, and from the main cavity to the second enclosed lumen. In some embodiments, an intraocular implant may comprise: a housing; a main cavity in the housing with one or more components provided therein; and one or more external flow-enabling features configured to increase flow of aqueous humor in proximity to the housing. In any of the preceding embodiments, the one or more external flow-enabling features may comprise a rib projecting from an external surface of the housing. In any of the preceding embodiments, the one or more external flow-enabling features may comprise a groove or channel formed in an external surface of the housing. In any of the preceding embodiments, the one or more external flow-enabling features may extend the entire axial length of the housing. In any of the preceding embodiments, the one or more external flow-enabling features may comprise an open-cell porous material. In some embodiments, a system for anchoring an intraocular implant in the eye of a patient may comprise: the intraocular implant; a first anchoring tether attached to the intraocular implant, the first anchoring tether including an anchoring loop portion which extends from the intraocular implant; and an anchoring tack including a penetrating tip configured to be inserted into eye tissue and a body portion configured to hold the intraocular implant in place at the eye tissue via the first anchoring tether. In any of the preceding embodiments, the first anchoring tether may include an attachment loop portion wrapped around the intraocular implant. In any of the preceding embodiments, the attachment loop portion may be generally perpendicular to the anchoring loop portion. In any of the preceding embodiments, the anchoring tack may be configured to hold the intraocular implant in place at the eye tissue via the anchoring loop portion of the first anchoring tether. In any of the preceding embodiments, the anchoring tack may be configured to be inserted through the anchoring loop portion. In any of the preceding embodiments, the anchoring tack may include a structure with a dimension that is larger than the diameter of the anchoring loop portion. In any of the preceding embodiments, the anchoring tack may comprise a drug delivery implant. In any of the preceding embodiments, the anchoring tacks may comprise a drainage stent. In any of the preceding embodiments, the first anchoring tether may comprise a wire. In any of the preceding embodiments, the system may further comprise a second anchoring tether, and the first anchoring tether may be connected to the intraocular implant at a first end and the second anchoring tether may be connected to the intraocular implant at a second end. In any of the preceding embodiments, the first anchoring tether may be attached to the intraocular implant by welding or brazing it to the intraocular implant, by use of an adhesive, or by passing through an eyelet. In some embodiments, a method for anchoring an intraocular implant in the eye of a patient may comprise: providing the intraocular implant, the intraocular implant including a first anchoring tether with an anchoring loop portion which extends from the intraocular implant; providing a first anchoring tack which includes a penetrating tip configured to be inserted into eye tissue; inserting the intraocular implant and the first anchoring tack into the eye; and inserting the penetrating tip of the first anchoring tack through the anchoring loop portion of the first anchoring tether and into the eye tissue. In any of the preceding embodiments, the penetrating tip of the first anchoring tack may be inserted through the anchoring loop portion of the first anchoring tether before inserting the intraocular implant and the first anchoring tether into the eye. In any of the preceding embodiments, the penetrating tip of the first anchoring tack may be inserted through the anchoring loop portion of the first anchoring tether after inserting the intraocular implant and the first anchoring tether into the eye. In any of the preceding embodiments, the penetrating tip of the first anchoring tack may be inserted through the anchoring loop portion of the first anchoring tether and into eye tissue in one motion. In any of the preceding embodiments, the intraocular implant may further include a second anchoring tether, and the method may further comprise: providing a second anchoring tack with an anchoring loop portion which extends from the intraocular implant; and inserting at least a portion of the second anchoring tack through the anchoring loop portion of the second anchoring tether. In some embodiments, an intraocular implant component may comprise: a substrate with a mounting surface, the mounting surface including an electrically-conductive via formed therein; and a thin-film battery mounted on the mounting surface of the substrate, the battery comprising, one or more electrically-active layers, an electrical terminal on the surface of the battery in contact with the via, a sealing layer formed over the one or more electrically-active layers, the sealing layer extending to the mounting surface of the substrate around the entire perimeter of the battery without a gap between the sealing layer and the mounting surface. In any of the preceding embodiments, the sealing layer may comprise a metal. In any of the preceding embodiments, the intraocular implant component may further comprise an insulating layer formed between the one or more electrically-active layers and the sealing layer. In any of the preceding embodiments, the substrate may comprise glass and the via may comprise silicon or metal. In any of the preceding embodiments, the substrate may comprise ceramic and the via may comprise metal. In any of the preceding embodiments, the thin-film battery may comprise a lithium-ion battery. In any of the preceding embodiments, the via may be flush with the mounting surface. In any of the preceding embodiments, the via may extend through the entire thickness of the substrate. In any of the preceding embodiments, the one or more electrically-active layers may include a cathode current collector layer, a cathode layer, an electrolyte layer, an anode current collector layer, or an anode layer. In any of the preceding embodiments, the battery may be mounted over the via. In any of the preceding embodiments, the battery may not include an electrical interconnect extending laterally from the battery over the substrate. In any of the preceding embodiments, the battery may be fabricated on the mounting surface of the substrate over the via. In some embodiments, an intraocular implant may comprise: a substrate with a mounting surface for one or more electrical components; a first electrical component mounted on the substrate; a second electrical component mounted on the substrate over the first electrical component such that the second electrical component spans the first electrical component and the first electrical component is located in a space between the second electrical component and the substrate. In any of the preceding embodiments, the first electrical component may comprise a battery. In any of the preceding embodiments, the battery may comprise a thin-film battery. In any of the preceding embodiments, the thickness of the film-film battery may be 30 μm or less. In any of the preceding embodiments, the second electrical component may comprise an integrated circuit. In any of the preceding embodiments, the second electrical component may be connected to the substrate by one or more solder bumps. In any of the preceding embodiments, the second electrical component may be connected to the substrate by one or more stud bumps. In any of the preceding embodiments, the one or more solder bumps may have a dimension which is larger than the thickness of the first electrical component. In any of the preceding embodiments, the one or more solder bumps may have a diameter greater than 50 μm. In some embodiments, an intraocular implant comprises: a housing; and an antenna provided in the housing, the antenna comprising a first row of a plurality of turns of wire which form at least a portion of a coil extending in a longitudinal direction, each of the plurality of turns of wire in the first row being in contact with an adjacent turn of wire in the longitudinal direction, and a second row of a plurality of turns of wire which form at least a portion of the coil, each of the plurality of turns of wire in the second row being in contact with an adjacent turn of wire in the longitudinal direction and an adjacent turn of wire in the radial direction. In any of the preceding embodiments, the self-resonant frequency of the antenna may be less than 100 MHz. In any of the preceding embodiments, the self-resonant frequency of the antenna may be less than 50 MHz. In any of the preceding embodiments, the intraocular implant may further comprise one or more electrical components provided in an interior space of the coil. In any of the preceding embodiments, at least one of the electrical components may comprise an integrated circuit implemented using subthreshold transistors. In any of the preceding embodiments, the antenna may not be connected to a capacitor or inductor circuit element which is used to tune an operating frequency of the antenna. In any of the preceding embodiments, the first row and the second row of turns of wire may be arranged such that electrical current travels through the first row and the second row in the same direction. In any of the preceding embodiments, the intraocular implant may further comprise one or more additional rows of turns of wire radially beyond the first row and the second row. In some embodiments, an intraocular implant may comprise: a tubular main body, the tubular main body including a first portion having a first diameter and a second portion having a second diameter which is larger than the first diameter; and an antenna at least partially located in the second portion of the tubular main body. In any of the preceding embodiments, the antenna may be completely located in the second portion of the tubular main body. In any of the preceding embodiments, the antenna may be a coil antenna. In any of the preceding embodiments, the diameter of the coil antenna may be larger than the first diameter of the first portion of the tubular main body. In any of the preceding embodiments, the tubular main body may be elongate. In any of the preceding embodiments, the implant may be sized and shaped to be inserted into the suprachoroidal/supraciliary space of a patient's eye. In any of the preceding embodiments, the intraocular implant may further comprise an intraocular pressure sensing module located in the second portion of the tubular main body. In any of the preceding embodiments, the first portion and the second portion of the tubular main body may be joined by a shoulder. In any of the preceding embodiments, the shoulder may be a step transition between the first portion and the second portion of the tubular main body. In some embodiments, an intraocular implant may comprise: a first pressure sensing module; a separate second pressure sensing module; and at least one controller module configured to determine pressure measurements using each of the first and second pressure sensing modules. In any of the preceding embodiments, either the first pressure sensing module or the second pressure sensing module may be provided in a housing with a measurement storage module, a controller module, or a transceiver module. In any of the preceding embodiments, both the first pressure sensing module and the second pressure sensing module may be provided in one or more housings with a measurement storage module, a controller module, or a transceiver module. In any of the preceding embodiments, the first pressure sensing module and the second pressure sensing module may be joined by a common housing. In any of the preceding embodiments, the housing may comprise an elongate tube. In any of the preceding embodiments, the first pressure sensing module and the second pressure sensing module may be joined by a tether. In any of the preceding embodiments, the tether may comprise a communication cable to communicate pressure measurements between the first pressure sensing module and the second pressure sensing module. In any of the preceding embodiments, the first pressure sensing module may be configured to be located in a first pressure-transmitting medium of a human eye and the second pressure sensing module may be configured to be located in a second pressure-transmitting medium of the eye. In any of the preceding embodiments, the first pressure-transmitting medium may have a pressure that is correlated with intraocular pressure and the second pressure-transmitting medium may have a pressure that is correlated with atmospheric pressure. In any of the preceding embodiments, the first pressure-transmitting medium may comprise aqueous humor of the eye. In any of the preceding embodiments, the second pressure-transmitting medium may comprise fluid under the conjunctiva of the eye. In any of the preceding embodiments, the controller may be configured to take pressure measurements from the first and second pressure sensing modules within ten minutes of one another. In any of the preceding embodiments, the controller may be configured to take pressure measurements from the first and second pressure sensing modules within one minute of one another. In any of the preceding embodiments, the controller may be configured to take pressure measurements from the first and second pressure sensing modules substantially concurrently. In any of the preceding embodiments, the controller may be configured to subtract a first measurement taken using either the first or second pressure sensing modules from a second measurement taken using the other of the first and second pressure sensing modules. In some embodiments, a method for inserting an intraocular implant may comprise: providing an intraocular implant with a first pressure sensing module, a separate second pressure sensing module, and at least one controller module configured to determine pressure measurements using each of the first and second pressure sensing modules; positioning the first pressure sensing module in a first pressure-transmitting medium of the eye; and positioning the second pressure sensing module in a second pressure-transmitting medium of the eye. In any of the preceding embodiments, the method may further comprise inserting at least a portion of the intraocular implant through the sclera of the eye. In any of the preceding embodiments, inserting at least a portion of the intraocular implant through the sclera of the eye may comprise using an ab interno technique. In any of the preceding embodiments, inserting at least a portion of the intraocular implant through the sclera may comprise forming a tunnel through the sclera using a tool. In any of the preceding embodiments, the tunnel through the sclera may be accessed through the suprachoroidal space of the eye. In any of the preceding embodiments, the first pressure-transmitting medium may comprise aqueous humor of the eye. In any of the preceding embodiments, the second pressure-transmitting medium may comprise fluid under the conjunctiva of the eye. In some embodiments, an intraocular implant may comprise: a differential pressure sensing module; and at least one controller module configured to determine a pressure measurement using the differential pressure sensing module. In any of the preceding embodiments, the differential pressure sensing module may comprise at least one flexible diaphragm. In any of the preceding embodiments, the differential pressure sensor may be provided at least partially in a housing, and the at least one flexible diaphragm may have two sides, the sides being exposed to external pressure at different regions of the housing. In any of the preceding embodiments, the at least one flexible diaphragm may be exposed to pressure via one or more channels. In any of the preceding embodiments, the at least one flexible diaphragm may be exposed to pressure via one or more pressure-transmitting fluids sealed inside the housing. In any of the preceding embodiments, the different locations may comprise different pressure-transmitting mediums of a human eye. In some embodiments, a method for inserting an intraocular implant may comprise: providing an intraocular implant with a housing, a differential pressure sensing module at least partially provided in the housing, the differential pressure sensing module comprising at least one flexible diaphragm having two sides exposed to external pressure at first and second different regions of the housing, the intraocular implant further comprising at least one controller module configured to determine a pressure measurement using the differential pressure sensing module; positioning the first region of the housing in a first pressure-transmitting medium of the eye; and positioning the second region of the housing in a second pressure-transmitting medium of the eye. In any of the preceding embodiments, the method may further comprise inserting at least a portion of the intraocular implant through the sclera of the eye. In any of the preceding embodiments, inserting at least a portion of the intraocular implant through the sclera of the eye may comprise using an ab interno technique. In any of the preceding embodiments, inserting at least a portion of the intraocular implant through the sclera may comprise forming a tunnel through the sclera using a tool. In any of the preceding embodiments, the tunnel through the sclera may be accessed through the suprachoroidal space of the eye. In any of the preceding embodiments, the first pressure-transmitting medium may comprise aqueous humor of the eye. In any of the preceding embodiments, the second pressure-transmitting medium may comprise fluid under the conjunctiva of the eye. Additional Considerations Various embodiments of implantable physiological sensors, and associated methods, with a variety of features, have been described herein. Although not every embodiment has been illustrated with every feature, it should be understood that the features described herein can be freely combined with the various embodiments that are described and illustrated. The various physiological sensors described herein can also have any feature, characteristic, element, etc. that is disclosed in connection with the sensor devices described in the following U.S. patent documents, which are each hereby incorporated by reference in their entirety: U.S. Pat. Nos. 6,981,958; 7,678,065; U.S. Patent Publication 2010/0056979; and U.S. Patent Publication 2010/0106073. In addition, the various physiological sensors described herein can be used in, for example, any manner or application that is described in the foregoing patent documents. The various illustrative devices, logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein can be implemented as, for example, electronic hardware (e.g., analog and/or digital circuitry), computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. The described functionality can be implemented in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the disclosure. Some of the various illustrative logical blocks, modules, and circuits described in connection with the embodiments disclosed herein can be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. Embodiments have been described in connection with the accompanying drawings. However, it should be understood that the figures are not necessarily drawn to scale. Distances, angles, etc. are merely illustrative and do not necessarily bear an exact relationship to actual dimensions and layout of the devices illustrated. In addition, the foregoing embodiments have been described at a level of detail to allow one of ordinary skill in the art to make and use the devices, systems, etc. described herein. A wide variety of variation is possible. Components, elements, and/or steps can be altered, added, removed, or rearranged. While certain embodiments have been explicitly described, other embodiments will become apparent to those of ordinary skill in the art based on this disclosure. The scope of certain inventions disclosed herein is indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

11857263

DESCRIPTION OF THE INVENTION Variations in the anatomy of the left atrium and pulmonary vein anatomy are much more common than was once believed.FIG.1is a graphic representation of the variations in the left atrium and pulmonary vein anatomy, as reported by Sohns et al in World Journal of Radiology (Sohns et al, World J Radiol 2011 Feb. 28; 3(2): 41-46). In this study, only about 61.3 percent of patients were found to have the classic textbook anatomy with four pulmonary veins connected to the left atrium. In the second most common variant, approximately 26.6 percent of patients had a left common trunk connecting the left pulmonary veins to the left atrium. Approximately 1.3 percent of patients had a right common trunk connecting the right pulmonary veins to the left atrium. As shown, other variations included one or more smaller, accessory pulmonary veins. Other studies have found similar percentages of atypical anatomy. Furthermore, even within these categories of anatomical variants, there can be considerable variation in terms of the size and location of the ostia of the pulmonary veins. Any of the pulmonary veins can be the location of arrythmogenic foci that give rise to anomalous electrical signals that are the cause of atrial fibrillation. Hunter et al reported that the single-procedure success rate for ablation treatment of atrial fibrillation was approximately 10 percent lower in patients with atypical anatomy of the pulmonary veins (Europace (2010) 12, 1691-1697). To be fully effective, ablation treatment must take these variations of anatomy into account. The one-size-fits-all approach of many existing devices may leave a significant number of patients inadequately treated. FIG.2shows images derived from three-dimensional imaging data, such as a CT scan or MRI, illustrating two variants of pulmonary vein anatomy. The reconstructed view is looking up at the roof of the atrium from inside the chamber of the atrium. Image A on the left illustrates the most common variant having four pulmonary veins connected to the left atrium. Dark circles are drawn around the ostia of the four pulmonary veins to show the desired areas for ablation. Image B on the right illustrates a less common variant having a shared ostium or common trunk connecting the two right pulmonary veins to the left atrium. Dark circles are drawn around the two ostia of the left pulmonary veins and the shared ostium of the right pulmonary veins to show the desired areas for ablation. The present invention provides devices and methods for ablation treatment of atrial fibrillation that takes into account the variations of anatomy of the patient's left atrium and pulmonary veins for improved procedural efficacy.FIG.3shows an example of a personalized ablation catheter device100for treatment of atrial fibrillation manufactured according to the present invention.FIG.4is a side view of the personalized ablation catheter device100ofFIG.3. The personalized ablation catheter device100has an ablation panel102that is made up of multiple ablation elements. The number of ablation elements is determined by the number of pulmonary vein ostia connected to the atrium and any other desired areas for creating ablation lesions. In this illustrative example, a first ablation element104is configured to encircle the right superior pulmonary vein, a second ablation element106is configured to encircle the right inferior pulmonary vein, a third ablation element108is configured to encircle the left superior pulmonary vein, and a fourth ablation element110is configured to encircle the left inferior pulmonary vein. Naturally, if there are only three pulmonary vein ostia present because of a left or right common trunk, the ablation panel102would only have three of these ablation elements. More ablation elements can be added if there are other accessory pulmonary vein ostia present. Connecting members105,107,109,111connect the ablation elements104,106,108,110together to form the ablation panel102. Because of anatomical variations, the size, shape and number of ablation elements104,106,108,110and connecting members105,107,109,111will vary. In some cases, the connecting members105,107,109,111may be configured as linear ablation elements. These linear ablation elements can be used for example to create a box lesion to electrically isolate the entire area between the pulmonary veins when clinically indicated. These and other variations can be made to personalize the ablation catheter device100to the specific patient's anatomy. The ablation elements are made of an electrically conductive material and are connected to a source of ablation energy by an electrical lead in the shaft of the ablation catheter device (not shown in this view). The ablation elements can be formed from one continuous loop of wire or each ablation element can be formed from a separate wire so that each ablation element can be energized selectively. In an alternative configuration, the ablation elements may have a multiplicity of ring-shaped electrodes spaced along a polymer catheter body. The ring-shaped electrodes may be separately connected to the ablation energy source so that they can be selectively energized to create a desired pattern of ablation lesions. For effective ablation of the pulmonary veins, the ablation panel102must be well apposed to the wall of the atrium. For this purpose, the personalized ablation catheter device100includes a base ring112that is configured to seat around the periphery of the patient's mitral valve. The ablation panel102is connected to the ring112by spring members114that urge the ablation panel102into contact with the upper wall of the atrium. The base ring112and the spring members114can be constructed of a metal, such as stainless steel or a superelastic nickel-titanium alloy, a polymer, or a composite of different materials. Additional features help to keep the ablation panel102aligned and apposed to the upper wall of the atrium. Ostial fitment elements116are connected to each of the ablation elements104,106,108,110and are configured to engage each of the pulmonary veins to align the ablation elements with each of the ostia. The ostial fitment elements116protrude into the ostia of the pulmonary veins to help maintain this alignment. On each of the ostial fitment elements116is a trigger electrode118that contacts the tissue inside of the pulmonary veins. Additionally, there is at least one sensor electrode120on the device that contacts the wall of the atrium outside of the area to be electrically isolated by ablation. For example, a sensor electrode120may be located on one of the connecting members105,107,109,111. Preferably, the personalized ablation catheter device100also provides a neuroprotective element, such as a neuroprotective mesh122that attaches across the base ring112to prevent potential emboli from entering the mitral valve. The mesh122will be made of a suitable woven, nonwoven or perforated material with pores sized to allow unimpeded blood flow while preventing passage of clots or other embolic particles above a certain size. For example, the mesh122may be a woven or nonwoven textile fabric made from natural, synthetic, polymeric or metallic fibers. This feature is especially advantageous because patients with atrial fibrillation are prone to forming clots within the atrium due to the inefficient pumping caused by the fibrillation. If these clots were to dislodge and flow to the brain, an embolic stroke could occur. Preferably, the neuroprotective mesh122is also configured to capture and remove potential emboli.FIGS.5A-5C and6A-6Bshow two possible configurations for accomplishing this function. FIGS.5A-5Cshow a neuroprotective element with a first layer of mesh122attached to the ring112of the ablation device as described above and a second layer of mesh124that is attached to a foldable wire rim126. The foldable wire rim126is approximately semicircular with ends that are pivotally attached to the ring112. When the device is first deployed, the second layer of mesh124is folded to the side, as shown inFIG.5A, so that embolic particles can accumulate on the first layer of mesh122. At the end of the procedure, prior to withdrawing the ablation device, the second layer of mesh124is closed over the first layer of mesh122by pivoting the foldable wire rim126, as shown inFIG.5B. A pull string or similar mechanism will be used to actuate the closing action.FIG.5Cshows the neuroprotective element in a closed position with any potential emboli trapped between the first layer of mesh122and the second layer of mesh124. FIGS.6A-6Bshow a neuroprotective element with a purse string128around the periphery of the neuroprotective mesh122. The neuroprotective mesh122can be in a pouch-like configuration or it can be made in two layers as in the example described above. When the device is first deployed, the neuroprotective mesh122is gathered around the periphery of the ring112of the ablation device, as shown inFIG.6A. At the end of the procedure, prior to withdrawing the ablation device, the neuroprotective mesh122is closed to trap any potential emboli by pulling the purse string128, as shown inFIG.6B. FIGS.7and8show a flowchart representing a method according to the present invention. The flowchart is divided into three portions, indicated by the large boxes drawn with dashed lines. The first portion130on the top ofFIG.7shows the steps for manufacturing a personalized ablation catheter device. The second portion132on the bottom ofFIG.7shows the steps for catheter placement. The third portion134inFIG.8shows the steps of a procedure or method for ablation treatment of atrial fibrillation using the personalized ablation catheter device. The steps of the method shown in the flowchart will be described in connection withFIGS.9-24. A first step of the manufacturing method is depicted inFIG.9in which 3-D imaging is performed to determine the anatomy of the patient's heart, particularly the left atrium and pulmonary veins. The 3-D imaging may include computed axial tomography (CT) scanning, multidetector computed tomography (MDCT), magnetic resonance imaging (MRI), ultrasound cardiac imaging, transesophageal echocardiography (TEE) or other known imaging techniques. Optionally, the anatomical imaging of the patient's left atrium and pulmonary veins can be combined with electrophysical mapping of the electrical activity of the patient's left atrium and pulmonary veins to locate suspected arrythmogenic foci. Electrophysical mapping can be performed with a multi-electrode sensing catheter. A 3-D computer model of the patient's left atrium and pulmonary veins is reconstructed Based on the 3-D imaging study, as represented inFIG.10. Then, 3-D modeling is used to design a personalized ablation catheter device that will create a desired pattern of ablation lesions based on the 3-D computer model of the patient's left atrium and pulmonary veins. The device design process can be done interactively on a computer. Alternatively, some or all of the device design process can be performed automatically by a computer.FIG.11shows a computer monitor where an ablation panel102of the personalized ablation catheter device is being designed based on the three-dimensional model of the patient's heart. The ablation elements in the ablation panel can be designed from scratch for each patient or the ablation elements and other components can be selected from a library of predesigned components.FIG.12shows the mesh ring112and spring elements114of the personalized ablation catheter device100being designed based on the three-dimensional model of the patient's heart. Similarly, the ring and the spring members can be designed from scratch or selected from a library of predesigned components. Next, a personalized patient-specific customized ablation catheter device100is fabricated that will create a desired pattern of ablation lesions according to the design that was based on the 3-D computer model of the patient's left atrium and pulmonary veins.FIG.13represents the step of manufacturing the personalized ablation catheter device that has been designed based on the three-dimensional model of a patient's heart. The personalized ablation catheter device can be manufactured using additive manufacturing, also known as 3-D printing, or using conventional fabrication techniques. Other fabrication techniques can be used such as wire bending and forming, polymer extrusion, heat forming, injection molding and CNC machining. Joining techniques such as welding, soldering, adhesive joining and fastener application can also be utilized. Alternatively, 3-D printing or CNC machining can be used to create a physical model of the patient's atrium and pulmonary ostia as an aid to designing and fabricating a personalized ablation catheter device. As another alternative, 3-D printing or CNC machining can be used to create a mold for casting, molding or forming a personalized ablation catheter device or some of its components. The neuroprotective mesh122is attached to the ring112and the ablation panel102is assembled to a catheter shaft140with electrical conductors142that are connected to the ablation elements, as shown inFIG.14. The catheter shaft140will have suitable connectors on the proximal end for connecting to a source of ablation energy. After it is assembled, the personalized ablation catheter device100is compressed and loaded into a lumen of a delivery catheter150prior to use. The delivery catheter150can be seen inFIGS.15-24. In a variation of the manufacturing method, the personalized ablation catheter device can be fabricated from a catheter blank on which a desired curve is produced using mechanical and/or thermal shaping methods. The catheter blank is an electrode catheter that starts out straight or with no particular curve. Alternatively or in addition, the desired curve can be produced on a guidewire or stylet that is inserted into a flexible electrode catheter. 3-D printing can be used to add additional features, such as the base ring112and the spring members114, to the catheter blank after it has been formed into a desired 3-D curve. The method of catheter placement begins with the step of percutaneous delivery of the personalized ablation catheter device100into the patient's left atrium via a transeptal route. The delivery catheter150with the personalized ablation catheter device100compressed inside of the lumen is inserted percutaneously into a large vein such as the femoral vein or jugular vein and advanced to the patient's vena cava and into the right atrium under fluoroscopic guidance. The delivery catheter150is advanced across the atrial septum into the patient's left atrium. Next, the personalized ablation catheter device100is deployed outside of the delivery catheter150inside the patient's left atrium.FIG.15shows the personalized ablation catheter device100being delivered via a transeptal approach and deployed within the patient's left atrium. FIG.16shows the personalized ablation catheter device100released within the patient's left atrium. Once the personalized ablation catheter device100has expanded to its full size within the left atrium, the catheter device100is rotated until the protrusions of the ostial fitment members engage the ostia of the pulmonary veins and the ring112engages the periphery of the mitral valve for proper alignment and apposition of the ablation elements. The procedure or method for ablation treatment of atrial fibrillation described in the flowchart inFIG.8begins with the personalized ablation catheter device100in place within the patient's left atrium. As depicted inFIG.17, the sensing electrode(s) of the personalized ablation catheter device100are used to sense electrical signals indicative of the rhythm of the patient's heart beat. If the patient is experiencing an arrhythmia, such as atrial fibrillation, this information will be used to help diagnose and locate any arrythmogenic foci. Next, a triggering signal is delivered through the triggering electrodes on each of the ostial fitment elements to see if it can trigger the arrhythmia so that the specific focus will be found and a target ablation around the specific ostium can be performed.FIG.18shows the triggering electrode on the ostial fitment elements applying the triggering signals. As depicted inFIG.19, the sensing electrode(s) of the personalized ablation catheter device are used to sense electrical signals that would indicate an arrhythmia had been triggered. If a specific focus is identified, the area around the corresponding pulmonary vein ostium will be ablated, as shown inFIG.20. If a specific focus is not identified, then the area around all of the pulmonary vein ostia will be ablated. Ablation energy, for example radiofrequency energy, is applied through the ablation elements of the catheter to create a desired pattern of ablation lesions to block anomalous electrical signals that give rise to atrial fibrillation. Other modes of ablation energy can also be used, for example impulses of bipolar direct current can be applied through the ablation elements. Alternatively, cryogenic ablation energy can be used. In this case, the ablation catheter would be modified to allow a flow of cryogenic fluid through an internal lumen of the catheter for heat exchange with the wall of the atrium. During the procedure, any clots or other emboli that are created or dislodged within the atrium are caught by the neuroprotective mesh, as shown inFIG.21. After the ablation step, the trigger electrodes are used again to determine whether the pulmonary veins have been electrically isolated. As shown inFIG.22, triggering signals are applied in each of the pulmonary veins, either all together or separately, while the sensing electrode(s) monitor the electrical signals, as shown inFIG.23. If the sensing electrode(s) located outside of the ablation elements do not detect the triggering signal, it shows that the pulmonary veins have been electrically isolated and the procedure is completed. If, however, the triggering signal is detected by one or more of the sensing electrode(s), it shows that there is a current leak through or around one of the ablation lesions. In this case, the ablation is repeated in one or more of the pulmonary veins, as shown inFIG.24, until electrical isolation is achieved. Once electrical isolation of the pulmonary veins has been achieved, the personalized ablation catheter device is withdrawn into the delivery catheter. Prior to withdrawal, the neuroprotective mesh112is closed, as shown inFIG.5C or6B, to capture and remove any potential emboli. The delivery catheter is then withdrawn and the venous puncture site is closed to achieve hemostasis. It is expected that the devices and methods described herein will significantly reduce the procedure time required for atrial fibrillation ablation procedures while achieving greater procedural efficacy and reducing the need for repeat ablation procedures.

11857264

DETAILED DESCRIPTION Embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings in which like numerals represent like elements throughout the several figures, and in which example embodiments are shown. Embodiments of the claims may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. The examples set forth herein are non-limiting examples and are merely examples among other possible examples. The words “comprising,” “having,” “containing,” and “including,” and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. It must also be noted that as used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. Although any systems and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, the preferred, systems and methods are now described. FIG.1Aillustrates a system152for providing assistance prior to or during an implant surgery, according to an embodiment. The system152can improve surgeries that involve implants by guiding selection and application of implants, delivery instruments, navigation tools, or the like. The system152can comprise hardware components that improve surgeries using, for example, a surgical assistance system164. In various implementations, the surgical assistance system164can obtain implant surgery information, converting the implant surgery information into a form compatible with an analysis procedure, applying the analysis procedure to obtain results, and using the results to provide a configuration for the implant surgery. An implant configuration can include characteristics of an implant such as various dimensions, angles, materials, application features (e.g., implant sizes, implant functionality, anchoring features, suture type, etc.), and/or aspects of applying the implant such as insertion point, delivery path, implant position/angle, rotation, amounts of force to apply (e.g., torque applied to a screw, rotational speed of a screw, rate of expansion of expandable implants, and so forth), etc. In some implementations, the implant surgery information can include images of a target area, such as MRI scans of a spine, patient information such as sex, weight, etc., or a surgeon's pre-operative plan. The surgical assistance system164can convert the implant surgery information, for example, by converting images into arrays of integers or histograms, entering patient information into feature vectors, or extracting values from the pre-operative plan. In some implementations, surgical assistance system164can analyze one or more images of a patient to identify one or more features of interest. The features of interest can include, without limitation, implantation sites, targeted features, non-targeted features, access paths, anatomical structures, or combinations thereof. The implantation sites can be determined based upon one or more of risk factors, patient information, surgical information, or combinations thereof. The risk factors can be determined by the surgical assistant system based upon the patient's medical history. For example, if the patient is susceptible to infections, the surgical assistant system164can recommend a minimally invasive procedure whereas the surgical assistant system may recommend open procedure access paths for patients less susceptible to infection. In some implementations, the physician can provide the risk factors before or during the procedure. Patient information can include, without limitation, patient sex, age, health rating, or the like. The surgical information can include available navigation systems, robotic surgery platforms, access tools, surgery kits, or the like. In some implementations, surgical assistance system164can apply analysis procedures by supplying the converted implant surgery information to a machine learning model trained to select implant configurations. For example, a neural network model can be trained to select pedicle screw configurations for a spinal surgery. The neural network can be trained with training items each comprising a set of images scans (e.g. camera, MRI, CT, x-ray, etc.) and patient information, an implant configuration used in the surgery, and/or a scored surgery outcome resulting from one or more of: surgeon feedback, patient recovery level, recovery time, results after a set number of years, etc. This neural network can receive the converted surgery information and provide output indicating the pedicle screw configuration. In other implementations, surgical assistance system164can apply the analysis procedure by A) localizing and classifying a surgery target, B) segmenting the target to determine boundaries, C) localizing optimal implant insertion points, D) identifying target structures (e.g. pedicles and isthmus), and/or computing implant configurations based on results of A-D. In yet further implementations, surgical assistance system164can apply the analysis procedure by building a virtual model of a surgery target area, localizing and classifying areas of interest within the virtual model, segmenting areas of interest, localizing insertion points, and computing implant configurations by simulating implant insertions in the virtual model. Each of the individual steps of these implementations can be accomplished using a machine learning model trained (as discussed below) to identify appropriate results for that step or by applying a corresponding algorithm. For example, an algorithm can measure an isthmus by determining an isthmus width in various images and tracking the minimal value across the images in different planes. In another example, surgical assistance system164can apply the analysis procedure by performing a finite element analysis on a generated three-dimensional model (e.g., a model of the patient's anatomy) to assess stresses, strains, deformation characteristics (e.g., load deformation characteristics), fracture characteristics (e.g., fracture toughness), fatigue life, etc. A virtual representation of the implant or other devices could be generated. The surgical assistance system164can generate a three-dimensional mesh to analyze the model. Machine learning techniques to create an optimized mesh based on a dataset of vertebrae or other bones and implants or other devices. After performing the analysis, the results could be used to refine the selection of screws or other implant components. The surgical assistance system164can incorporate results from the analysis procedure in suggestions for the implant surgery. For example, the results can be used to indicate suggested implants for a procedure, to annotate an image with suggested insertions points and angles, to generate a virtual reality or augmented reality representation including the suggested implant configurations, to provide warnings or other feedback to surgeons during a procedure, to automatically order the necessary implants, to generate surgical technique information (e.g., insertion forces/torques, imaging techniques, delivery instrument information, or the like), etc. The surgical assistance system164can improve the efficiency, precision, and/or efficacy of implant surgeries by providing more optimal implant configuration guidance. This can reduce operational risks and costs produced by surgical complications, reduce the resources required for preoperative planning efforts, and reduce the need for extensive implant variety to be prepared prior to an implant surgery. The surgical assistance system164provides increased precision and efficiency for patients and surgeons. In orthopedic surgeries, the surgical assistance system164can select or recommend implants (e.g., permanent implants, removable implants, etc.), surgical techniques, patient treatment plans, or the like. For example, the implants can be joint replacements, hip implants, removable bone screws, or the like. The surgical techniques can include access instruments selected based on one or more criteria, such as risk of adverse events, optical implant position, protected zones (e.g., zones with nerve tissue), or the like. In spinal surgeries, the surgical assistance system164can reduce incorrect selection of pedicle screw types, dimensions, and trajectories while making surgeons more efficient and precise, as compared to existing surgical procedures. The surgical assistance system164can also improve surgical robotics/navigation systems, providing improved intelligence for selecting implant application parameters. For example, the surgical assistance system164empowers surgical robots and navigation systems for spinal surgeries to increase procedure efficiency and reduce surgery duration by providing information on types and sizes, along with expected insertion angles. In addition, hospitals benefit from reduced surgery durations and reduced costs of purchasing, shipping, and storing alternative implant options. Medical imaging and viewing technologies can integrate with the surgical assistance system164, to provide more intelligent and intuitive results. The surgical assistance system164can be incorporated in system152, which can include one or more input devices120that provide input to the processor(s)145(e.g. CPU(s), GPU(s), HPU(s), etc.), notifying it of actions. The actions can be mediated by a hardware controller that interprets the signals received from the input device and communicates the information to the processors145using a communication protocol. Input devices120include, for example, a mouse, a keyboard, a touchscreen, an infrared sensor, a touchpad, a wearable input device, a camera- or image-based input device, a microphone, or other user input devices. Processors145can be a single processing unit or multiple processing units in a device or distributed across multiple devices. Processors145can be coupled to other hardware devices, for example, with the use of a bus, such as a PCI bus or SCSI bus. The processors145can communicate with a hardware controller for devices, such as for a display130. Display130can be used to display text and graphics. In some implementations, display130provides graphical and textual visual feedback to a user. In some implementations, display130includes the input device as part of the display, such as when the input device is a touchscreen or is equipped with an eye direction monitoring system. In some implementations, the display is separate from the input device. Examples of display devices are: an LCD display screen, an LED display screen, a projected, holographic, or augmented reality display (such as a heads-up display device or a head-mounted device), and so on. Other I/O devices140can also be coupled to the processor, such as a network card, video card, audio card, USB, firewire or other external device, camera, printer, speakers, CD-ROM drive, DVD drive, disk drive, or Blu-Ray device. Other I/O140can also include input ports for information from directly connected medical equipment such as MRI machines, X-Ray machines, etc. Other I/O140can further include input ports for receiving data from these types of machine from other sources, such as across a network or from previously captured data, e.g. stored in a database. In some implementations, the system152also includes a communication device capable of communicating wirelessly or wire-based with a network node. The communication device can communicate with another device or a server through a network using, for example, TCP/IP protocols. System152can utilize the communication device to distribute operations across multiple network devices. The processors145can have access to a memory150in a device or distributed across multiple devices. A memory includes one or more of various hardware devices for volatile and non-volatile storage, and can include both read-only and writable memory. For example, a memory can comprise random access memory (RAM), various caches, CPU registers, read-only memory (ROM), and writable non-volatile memory, such as flash memory, hard drives, floppy disks, CDs, DVDs, magnetic storage devices, tape drives, device buffers, and so forth. A memory is not a propagating signal divorced from underlying hardware; a memory is thus non-transitory. Memory150can include program memory160that stores programs and software, such as an operating system162, surgical assistance system164, and other application programs166. Memory150can also include data memory170that can include, e.g. implant surgery information, configuration data, settings, user options or preferences, etc., which can be provided to the program memory160or any element of the system152. Some implementations can be operational with numerous other computing system environments or configurations. Examples of computing systems, environments, and/or configurations that may be suitable for use with the technology include, but are not limited to, personal computers, server computers, handheld or laptop devices, cellular telephones, wearable electronics, tablet devices, multiprocessor systems, microprocessor-based systems, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments that include any of the above systems or devices, or the like. FIG.1Billustrates a network connection diagram100of a system102for providing assistance to a surgeon during a spinal surgery, according to an embodiment. The system102may be connected to a communication network104. The communication network104may further be connected with a network in the form of a precision spine network106for allowing data transfer between the system102and the precision spine network106. The communication network104may be a wired and/or a wireless network. The communication network104, if wireless, may be implemented using communication techniques such as Visible Light Communication (VLC), Worldwide Interoperability for Microwave Access (WiMAX), Long term evolution (LTE), Wireless local area network (WLAN), Infrared (IR) communication, Public Switched Telephone Network (PSTN), Radio waves, and other communication techniques known in the art. In one embodiment, the precision spine network106may be implemented as a facility over “the cloud” and may include a group of modules. The group of modules may include a Precision Spine Network Base (PSNB) module108, an abnormalities module110, an XZ screw angle module112, an XY screw module114, and a screw size module116. The PSNB module108may be configured to store images of patients and types of spinal screws, required in spinal surgeries. In some implementations, a similar module can be used for other types of surgeries. While the PSNB is referred to below, in each instance other similar modules can be used for other types of surgeries. For example, a Precision Knee Network Based can be used to assist in anterior cruciate ligament (ACL) replacement surgeries. The images may be any of camera images, Magnetic Resonance Imaging (MRI) images, ultrasound images, Computerized Aided Tomography (CAT) scan images, Positron Emission Tomography (PET) images, and X-Ray images. In one case, the images may be analyzed to identify abnormalities and salient features in the images, for performing spinal surgeries on the patients. In some implementations, the PSNB module108can store additional implant surgery information, such as patient information, (e.g. sex, age, height, weight, type of pathology, occupation, activity level, tissue information, health rating, etc.), specifics of implant systems (e.g. types and dimensions), availability of available implants, aspects of a surgeon's preoperative plan (e.g. surgeon's initial implant configuration, detection and measurement of the patient's anatomy on images, etc.), etc. In some implementations, the PSNB module108can convert the implant surgery information into formats useable for implant suggestion models and algorithms. For example, the implant surgery information can be tagged with particular identifiers for formulas or can be converted into numerical representations suitable for supplying to a machine learning model. The abnormalities module110may measure distances between a number of salient features of one vertebra with salient features of another vertebra, for identifying disk pinches or bulges. Based on the identified disk pinches or bulges, herniated disks may be identified in the patients. It should be obvious to those skilled in the art, that given a wide variety of salient features and geometric rules, many spinal abnormalities could be identified. If the spinal abnormalities are identified, the PSNB module108may graphically identify areas having the spinal abnormalities and may send such information to a user device118. In one embodiment, information related to spinal surgeries may be displayed through a Graphical User Interface (GUI) of the user device118, as illustrated usingFIG.1B. A smart phone is shown as the user device118inFIG.1B, as an example. Further, the user device118may be any other device including a GUI, for example, a laptop, desktop, tablet, phablet, or other such devices known in the art. The XZ screw angle module112may determine an XZ angle of a spinal screw or other implant to be used during the surgery. Further, the XY screw angle module114may determine an XY angle of the implant. The XZ screw angle module112and the XY screw angle module114may determine a position entry point for at least one spinal screw. The XZ screw angle module112and the XY screw angle module114may graphically represent the identified data and may send such information to the user device118. The screw size module116may be used to determine a screw diameter (e.g., a maximum screw diameter) and a length of the screw based on the salient features identified from the images of the patients. In some implementations, the XZ screw angle module112, the XY screw angle module114, and the screw size module116can identify implant configurations for other types of implants in addition to, or other than screws (e.g., pedicle screws, facet screws, etc.) such as cages, plates, rods, disks, fusions devices, spacers, rods, expandable devices, etc. In addition, these modules may suggest implant configurations in relation to references other than an X, Y, Z, coordinate system. For example, in a spinal surgery, the suggestions can be in reference to the sagittal plane, mid-sagittal plane, coronal plane, frontal plane, or transverse plane. As another example, in an ACL replacement surgery, the suggestions can be an angle for a tibial tunnel in reference to the frontal plane of the femur. In various implementations, the XZ screw angle module112, the XY screw angle module114, or screw size module116can identify implant configurations using machine learning modules, algorithms, or combinations thereof, as described below in relation toFIGS.6-9. In one embodiment, referring toFIG.2, a block diagram showing different components of the system102is explained. The system102includes a processor202, interface(s)204, and a memory206. The processor202may execute an algorithm stored in the memory206for augmenting an implant surgery, e.g. by providing assistance to a surgeon during a spinal or other implant surgery, by providing controls to a robotic apparatus (e.g., robotic surgery systems, navigation system, etc.) for an implant surgery or by generating suggestions for implant configurations to be used in an implant surgery. The processor202may also be configured to decode and execute any instructions received from one or more other electronic devices or server(s). The processor202may include one or more general purpose processors (e.g., INTEL® or Advanced Micro Devices® (AMD) microprocessors) and/or one or more special purpose processors (e.g., digital signal processors or Xilinx® System On Chip (SOC) Field Programmable Gate Array (FPGA) processor). The processor202may be configured to execute one or more computer-readable program instructions, such as program instructions to carry out any of the functions described in this description. The interface(s)204may help a user to interact with the system102. The user may be any of an operator, a technician, a doctor, a doctor's assistant, or another automated system controlled by the system102. The interface(s)204of the system102may either accept an input from the user or provide an output to the user, or may perform both the actions. The interface(s)204may either be a Command Line Interface (CLI), Graphical User Interface (GUI), or a voice interface. The memory206may include, but is not limited to, fixed (hard) drives, magnetic tape, floppy diskettes, optical disks, Compact Disc Read-Only Memories (CD-ROMs), and magneto-optical disks, semiconductor memories, such as ROMs, Random Access Memories (RAMs), Programmable Read-Only Memories (PROMs), Erasable PROMs (EPROMs), Electrically Erasable PROMs (EEPROMs), flash memory, magnetic or optical cards, or other type of media/machine-readable medium suitable for storing electronic instructions. The memory206may include modules, implemented as programmed instructions executed by the processor202. In one case, the memory206may include a design module208for receiving information from the abnormalities module110. The design module208may poll the surgeon for an information request. The design module208may allow the surgeon to design the spinal screw and change the generated implant configurations, such as the entry point (e.g., entry point into the patient, entry points into a vertebra, entry points to the implantation site, etc.), and screw or other implant angles in any of various planes. If the surgeon changes the entry point or angles, the system can automatically update other features of the implant configuration to account for the changes, such as the implant dimensions (e.g. screw diameter, thread pitch, or length). The design module208may include patient data210. The patient data210may include images of patients and may allow the surgeon to identify the patients. A patient may refer to a person on whom and operations is to be performed. The patient data210may include images of patients, received from the user device118. In one embodiment, areas of interest may be defined in diagnostic data of a patient. In one case, the system102may determine the areas of interest based on pre-defined rules or using machine learning models, as described below in relation toFIGS.6-9. In another case, the areas of interest may be defined based on a surgeon's input. In one case, the diagnostic data may include images of the patient. The images may be any of camera images, Magnetic Resonance Imaging (MRI) images, ultrasound images, Computerized Aided Tomography (CAT) scan images, Positron Emission Tomography (PET) images, and X-Ray images. In one case, the images of the patients may be stored in the patient surgeon database210. Post defining the areas of interest, a screw bone type may be defined based on various models and/or the surgeon's input. Successively, salient features of the areas of interest may be identified in the images of the patients, e.g. by applying the procedures described below.FIG.3Ashows salient points present in a top view of a vertebra of the patient, according to an embodiment. The salient points are shown as bubbles i.e. ‘e1,’ ‘e2,’ and ‘f2.’ Further,FIG.3Bshows salient points present in a side view of the vertebra of the patient, according to an embodiment. The salient points are shown as bubbles i.e. ‘ki,’ ‘ku,’ ‘hu,’ ‘im,’ and ‘z’.′ Successively, based on the salient points of the areas of interest, the system102may determine implant configurations (e.g. angles and entry point, implant orientation, implant movement, etc.) using the analysis procedures.FIG.4Aillustrates computations for determining the XZ angle (ϕ)402using the salient points, according to an embodiment. It should be noted that positions of X and Y co-ordinates of the regions of interest may be determined based on a location of at least one salient feature present in the image. FIG.4Billustrates computations for determining the XY angle (θ)406using the salient points, according to an embodiment. It should be noted that positions of X and Y co-ordinates of the regions of interest may be determined based on a location of at least one salient feature present in the image. Further,FIG.4Aillustrates a position entry point404for the spinal screw, andFIG.4Billustrates a position entry point408for the spinal screw. Upon determining, MRI data including the XY angle, the XZ angle, and the position entry point for the spinal screw, may be stored in the abnormalities module110. Post identification of the angels and the entry point for an implant, the system102may determine additional implant configuration features. For example, the system102can determine a maximum implant (e.g. spinal screw) diameter, a minimum implant diameter, and a length of the implant to be used during a spinal surgery. For example, upon determining the maximum spinal screw diameter and the length of the spinal screw, the procedure MRI data may be updated in the abnormalities module110. In the spinal surgery example, the spinal screw having the determined maximum screw diameter and the length may be identified. The spinal screw may be suggested, to the surgeon, for usage during the spinal surgery. In one case, a spinal screw HA and dimensions of the spinal screw HA may be illustrated for the surgeon's selection, as shown inFIG.5. As illustrated inFIG.5, a schematic showing different parameters of the spinal screw HA, dimensions of the spinal screw HA, and a schematic of threads of the spinal screw HA are shown, according to an embodiment. Further, different such details related to spinal screws HB, spinal screws HD, and other known spinal screws may be presented to the surgeon for usage during the spinal surgery, thereby assisting the surgeon during the spinal surgery. As another example, for an ACL replacement, upon determining the entry point and angle for a tibial tunnel for attaching a replacement graft, the system102can identify a depth for the tibial tunnel such that it will end above the center of the knee joint without piercing surrounding tissue. In addition, dimensions for the ACL graft itself and/or for screws or other fastening components can be suggested. The flowchart600ofFIG.6shows the architecture, functionality, and operation for providing assistance to a surgeon during a spinal surgery, according to an embodiment. One skilled in the art will appreciate that, for this and other processes and methods disclosed herein, the functions performed in the processes and methods may be implemented in differing order. Furthermore, the outlined steps and operations are only provided as examples, and some of the steps and operations may be optional, combined into fewer steps and operations, or expanded into additional steps and operations without detracting from the essence of the disclosed embodiments. For example, two blocks shown in succession inFIG.6may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. Any process descriptions or blocks in flowcharts should be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps in the process, and alternate implementations are included within the scope of the example embodiments in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved. In addition, the process descriptions or blocks in flow charts should be understood as representing decisions made by a hardware structure such as a state machine. The flowchart600starts at step602and concludes at step610. At step602, areas of interest may be defined in diagnostic data of a patient and a screw bone type may be defined, during a spinal surgery. The diagnostic data may include images of the patient. The images may be any of camera images, Magnetic Resonance Imaging (MRI) images, ultrasound images, Computerized Aided Tomography (CAT) scan images, Positron Emission Tomography (PET) images, and X-Ray images. At step604, salient features of areas of interest may be identified from the diagnostic data. In one case, the images may be analyzed to identify abnormalities and the salient features, for performing spinal surgeries on the patients. At step606, an XZ angle, an XY angle, and a position entry point for an implant (e.g. a spinal screw) are determined. In one case, the XZ angle, the XY angle, and the position entry point may be determined based on the salient features. At step608, a maximum screw diameter and a length of the screw to be used during the spinal surgery may be determined based on the XY angle, the XZ angle, and the position entry point of the screw. Upon determining the maximum screw diameter and the length of the screw, the procedure MRI data may be updated in an abnormalities module110. At step610, the screw implant to be used during a surgery may be identified and suggested to a surgeon. The screw implant may be identified based on the maximum screw diameter and the length of the screw. FIG.7illustrates a flowchart showing a method700for generating implant configurations. At block702, method700can obtain implant surgery information such as images, patent history, circumstance, test results, biographic data, surgeon recommendations, implant specifics, etc. Implant surgery images can be of parts of a patient, such as camera images, Magnetic Resonance Imaging (MRI) images, ultrasound images, Computerized Aided Tomography (CAT) scan images, Positron Emission Tomography (PET) images, X-Ray images, 2D or 3D virtual models, CAD models, etc. Additional implant surgery information can include, e.g. sex, age, height, weight, type of pathology, occupation, activity level, implant types and dimensions, availability of available implants, or aspects of a surgeon's preoperative plan (e.g. surgeon's initial implant configuration, detection and measurement of the patient's anatomy on images, etc.) The implant surgery information can be obtained in various manners such as through direct user input (e.g. through a terminal or by interacting with a web service), through automatic interfacing with networked databases (e.g. connecting to patient records stored by a hospital, laboratory, medical data repositories, etc.), by scanning documents, or through connected scanning, imaging, or other equipment. The patient data can be gathered with appropriate consent and safeguards to remain HIPPA compliant. At block704, method700can convert the implant surgery information obtained at block702to be compatible with analysis procedures. The conversion can depend on the analysis procedure that will be used. As discussed below in relation to block706, analysis procedures can include directly applying a machine learning model, applying an algorithm with multiple stages where any of the stages can provide machine learning model predictions (seeFIG.8A), or applying a virtual modeling system (seeFIG.8B). In some implementations, the conversion of the implant surgery information can include formatting the implant surgery information for entry to a machine learning model. For example, information such as patient sex, height, weight, etc. can be entered in a feature vector, such as a sparse vector with values corresponding to available patient characteristics. In some implementations, the conversions can include transforming images from the implant surgery information into a format suitable for input to a machine learning model, e.g. an array of integers representing pixels of the image, histograms, etc. In some implementations, the conversion can include identifying surgery target features (detection and measurement of the patient's anatomy on images), characterizing surgery targets, or modeling (i.e. creating a virtual model of) the implant surgery target. For example, in a spinal surgery, this can include measuring vertebrae features on an image, converting 2D images of vertebrae into a 3D model, or identifying which vertebrae from a series of images are to be the target of the implant operation. As another example, in an ACL replacement surgery, this can include identifying and measuring features in an image such as location, size, and spacing of anatomy such as of the femur, patella, remaining portion of meniscus, other ligaments, etc., converting 2D images of the knee into a 3D model, or identifying other areas of damage (e.g. fractures, torn cartilage, other ligament tears, etc.). In various implementations, the conversion process can be automatic, human supervised, or performed by a human technician, e.g. using tools such as a digital ruler and a digital angle finder. Further in the spinal surgery example, the conversion can include identifying a target set of vertebrae, initially localizing and marking the target set of vertebrae, performing segmentation for each of the target set of vertebrae, and marking cortical boundaries. In some implementations, input for the spinal implant surgery can specify a target set of vertebrae, however the surgical assistance system164can automatically perform calculations for additional vertebrae that weren't specified in the inputs. This can give the surgeon an option to expand the set of vertebrae to be fused, either prior to the operation or even during the procedure. In the ACL replacement surgery example, the conversion can include identifying a graft type (e.g. patella tendon, hamstring, cadaver ACL, etc.), initially localizing or marking the target drilling sites, performing segmentation for the target features (e.g. end of the femur), and marking boundaries (e.g. bone edges, meniscus edges, synovial membrane, etc.). At block706, method700can apply analysis procedures, using the converted implant surgery information from block704, to identify implant configuration(s). In various implementations, the analysis procedures can include directly applying a machine learning model, applying a sequence of steps that can include one or more machine learning models, and/or generating a virtual model of the surgery target area and applying heuristics for implant configuration selection. To apply a machine learning model directly, method700can provide the converted implant information to a machine learning model trained to specify implant configurations. A machine learning model can be trained to take input such as representations of a series of images and a feature vector for the patient and other aspects of the surgery (e.g. implant availability, surgeon specialties or ability indicators, equipment available, etc.) and can produce results that implant configurations. For example, for a spinal surgery, the machine learning model can suggest pedicle screw configurations, e.g. characteristics such as screw diameter, length, threading and application parameters such as screw insertion point, angle, rotation speed, etc. As another example, for an ACL replacement surgery, the machine learning model can suggest graft type, attachment type (e.g. screw material, length, or configuration features), graft attachment locations, drill depths, etc. In some implementations, the converted implant information can be used in a multi-stage process for selecting aspects of an implant configuration. For example, for a spinal surgery, the multi-stage process can include method800or method850, discussed below. In various steps of this these processes, either an algorithm can be used to generate results for that step or a machine learning model, trained for that step, can be applied. In some implementations, the procedure for identifying implant configurations for a spinal surgery can include processing implant surgery information to locate targeted vertebrae and their pedicles in images, on available axes; identifying and tagging vertebrae characteristics; determining a preferred screw insertion point based on a mapping between tags and insertion point criteria (e.g. where the mapping can be a representation of a medical definition of a pedicle screw insertion point—described below); performing measurements, on the images, of the pedicle isthmus width and height and length of the pedicle and vertebral body, starting at the preferred insertion point; measuring the angle between the line used to determine length and the sagittal plane, in the axial view; and measuring the angle between that length line and the axial plane. In some implementations, machine learning models can be trained to perform some of these tasks for identifying implant configurations. For example, machine learning models can be trained to identify particular vertebral pedicles in various images, which can then be atomically measured and aggregated across images, e.g. storing minimal, maximal, median, or average values, as appropriate given the target being measured. As another example, a machine learning model can receive the set of images and determine an order or can select a subset of the images, for automatic or manual processing. In some implementations, a machine learning model can be used to localize and classify the target within an image, such as by identifying a target vertebra or localizing the end of the femur or meniscus edges. In some implementations, a machine learning model can be used to segment target vertebrae, femur, tibia, or other anatomical features in the target area, to determine their boundaries. In some implementations, a machine learning model can be used to localize insertion points. In some implementations, a machine learning model can be used to segment images to determine boundaries of anatomical structures (e.g., boundaries of bones, organs, vessels, etc.), density of tissue, characteristics of tissue, or the like. In various implementations, the results from the above stages can be used in inference formulae to compute the implant configurations. For example, a maximal screw diameter can be determined using the smallest pedicle isthmus dimension found across all the images of the target vertebrae (which can be adjusted to include a safety buffer). As another example, a maximal screw length can be determined using the smallest measurement of pedicle and vertebral body length, across all the target vertebra in question (which can be adjusted to include a safety buffer). Machine learning models, as used herein, can be of various types, such as Convolutional Neural Networks (CNNs), other types of neural networks (e.g. fully connected), decision trees, forests of classification trees, Support Vector Machines, etc. Machine learning models can be trained to produce particular types of results, as discussed below in relation toFIG.9. For example, a training procedure can include obtaining suitable training items with input associated with a result, applying each training item to the model, and updating model parameters based on comparison of model result to training item result. In some implementations, automated selection of implant configurations can be limited to only cases likely to produce good results, e.g. only for certain pathologies, types of patients, surgery targets (e.g. the part of the spine that needs to be fused), or where confidence scores associated with machine learning model outputs are above a threshold. For example, in the spinal surgery example, automation can be limited to common types of spinal fusions, such as L3/L4, L4/L5, or L5/S1, certain pathologies such as spondylolisthesis or trauma, or patients with certain characteristics, such as being in a certain age group. As another example, for an ACL replacement, automation can be limited to cases without other ligament tears. At block708, method700can provide results specifying one or more features of an implant configuration. For example, the results for a spinal surgery can include selection of pedicle screw type and dimensions for each vertebra and guidance on an insertion point and angle for each screw. As another example, results for an ACL replacement surgery can include selection of implant graft type, connection type, joint dimensions, and guidance on connection points such as drill locations and depths. In some implementations, the results can be specified in a natural language, e.g. using templates that can be filled in with recommendations. In some cases, the results from the analysis of block706can be mapped to particular reasons for the implant configuration recommendations, and these reasons can be supplied along with the recommendations. In some implementations, the results can be based on medical definitions of preferred implant configurations, where the preferred implant configurations can be mapped to a particular surgical target area based on the results from block706. For example, results for spinal surgery pedicle screws can include a preferred insertion point, e.g. defined, for lumbar vertebrae, at the intersection of the superior articular facet, transverse process, and pars interarticularis; and for thoracic spine or cervical spine, at the intersection of the superior articular facet plane and transverse process. As another example, a preferred screw angle can be, in axial view, the angle between the sagittal plane and the line defined by the insertion point and midpoint of the pedicle isthmus. In sagittal view the preferred screw angle can be parallel to the superior vertebral endplate. In addition, a maximal screw length can be defined as the distance between the insertion point and the far cortical boundary of the vertebra, at a particular screw angle. A maximal screw diameter can be the minimal width of the pedicle isthmus, on any axis. Each of these can be modified to include a certain safety buffer, which can vary depending on the size of the vertebra. The results from block706can identify features of an individual patient, which can be used in conjunction with the foregoing implant configuration definitions to specify patient specific implant configurations, e.g. in natural language, as image annotations, in a 3D model, as discussed below. The implant configuration results can be specified in various formats. For example, results can be in a natural language, coordinates one of various coordinate systems, as instructions for a robotic system, as annotations to one or more images, or as a virtual model of the surgery target area. The results can be used to augment the implant surgery in multiple ways. For example, results can be added to a preoperative plan. Results can trigger acquisition of implant materials, such as by having selected implants ordered automatically or having designs for patient-specific screws provided for 3D-printing. As another example, results can be used to provide recommendations during a surgical procedure, e.g. with text or visual annotations provided as overlies on a flat panel display, through auditory or haptic feedback alerts, or using an AR or VR system, e.g. to display an overlay of the implant on the patient anatomy or to display guidance on the suggested insertion point and angle. In some implementations, the results can be used to control robotic systems, e.g. causing a robotic arm to align itself according to the recommended insertion point and angle, which may be first confirmed by a surgeon. The method700can be used in a wide range of procedures, e.g. open procedures, minimally invasive procedures, orthopedic procedures, neurological procedures, reconstructive implants, maxillofacial procedures (e.g., maxillary implants), or other procedure. In some surgical procedures, the implant information at block702can include implant dimensions, material information (e.g., composition of implant), and images of the patient. At block706, the implant configuration can be implant dimensions (e.g., when in a delivery state or implanted state), implant functionality, or the like. FIG.8Aillustrates a flowchart showing a method800for applying analysis procedures that can utilize machine learning models, according to an embodiment. In some implementations, method800is performed as a sub-process of block706. At block802, method800can receive implant surgery information. This can be some of the converted implant surgery information from block704. In some implementations, the implant surgery information can include one or more images of the surgery target area, e.g. MRI scans of a spine, X-rays of a wrist, ultrasound images of an abdomen, etc. At block804, method800can localize and classify a target in one or more of the images of the surgery target area. In various implementations, this can be accomplished by applying a machine learning model trained for the particular target area to identify surgical targets or by finding a centroid point of each displayed vertebra, performing vertebral classification using image recognition algorithms, and determining whether the classified vertebrae match a list of vertebrae identified for the surgery. In some implementations, if the image does not contain at least one target of interest, the image can be disregarded from further processing. At block806, method800can segment the identified target(s) from block804to determine their boundaries. At block808, method800can localize implant insertion points. In some implementations, blocks806and808can be performed using machine learning models or algorithms, e.g. that identify particular patterns, changes in color, shapes, etc. At block810, method800can localize and segment individual target features. For example, in a spinal surgery where targets are vertebrae, at block810method800can identify vertebrae pedicles and their isthmus, and measure these features. In some implementations, this can be accomplished using a machine learning model trained to detect each type of feature. In some implementations, detecting the pedicle and the isthmus of vertebra from annotated images can include measuring the isthmus width and tracking the minimal value across images and planes, defining the angle between the line that passes through at least two midpoints in the pedicle, and the reference plane, measuring the maximal length through that line, and tracking the minimal value across measurements. In some implementations, isthmus determination and measurement can be accomplished by starting at a point inside a pedicle, computing the distance to pedicle borders in multiple directions, taking the minimum length. In other implementations, the isthmus determination and measurement can be accomplished by scanning, for example using horizontal lines that intersect with pedicle borders in an axial view, and finding the minimum-length line. In some implementations, the steps performed at any of blocks804-810can be repeated for each of multiple target area images, aggregating results from the multiple images. For example, in a step for identifying and measuring vertebrae pedicles, an aggregated measurement for a particular pedicle can be the minimum measured width of the pedicle from all of the images showing that particular pedicle. At block812, method800can use results from any of blocks804-810to compute an implant configuration (e.g. characteristics and application parameters). For example, the minimum width of a pedicle found across the images showing that pedicle, with some buffer added, can be the selected width characteristic of a pedicle screw implant. As another example, a screw angle could be determined using an identified insertion point and a center of the pedicle isthmus, with respect to center axis, depending on the image plane. The angles in axial and sagittal planes can be either the median or average angles across the multiple images. As a further example, a maximal screw length can be determined as the length of the line defined by the insertion point, the insertion angle, and the point where the line hits the cortical wall of the vertebra, minus some safety buffer. This length can be computed from multiple images and the minimum across all the images can be used for of this screw. FIG.8Billustrates a flowchart showing a method850for applying analysis procedures that can utilize virtual models, according to an embodiment. In some implementations, method850is performed as a sub-process of block706. At block852, method850can receive implant surgery information. This can be some of the converted implant surgery information from block704. In some implementations, the implant surgery information can include one or more images of the surgery target area. At block854, method850can build one or more virtual models of the target surgery area based on the images and/or other measurement data in the implant surgery information. A virtual model, as used herein, is a computerized representation of physical objects, such as the target area of a surgery (e.g. portions of a patient's spine) and/or implants (e.g. screws, rods, etc.). In some implementations, virtual models can be operated according to known physical properties, e.g. reactions to forces can be predicted according to known causal relationships. In various implementations, the virtual models generated by method850can be two-dimensional models or three-dimensional models. For example, a two-dimensional model can be generated by identifying portions of an image as corresponding to parts of a patient's anatomy, such that a computing system can determine how implant characteristics would fit in relation to the determined anatomy parts. As another example, a three-dimensional model can be generated by identifying shapes and features in individual images, from a set of successive images, and mapping the identified shapes and features into a virtual three-dimensional space, using relationships between images. Finite element analysis techniques can be used to predict stresses, strains, pressures, facture, and other information and be used to design implants, surgical tools, surgical techniques, etc. For example, the implant configuration can be determined based on predetermined stresses (e.g., maximum allowable stresses in the tissue and/or implant, yield strength of anatomical structures and/or implant components, etc.), fracture mechanics, or other criteria defined by the physician or automatically determined based on, for example, tissue characteristics, implant design, or the like. In some embodiments, fatigue life can be predicted using stress or strain based techniques. A virtual model can also analyze mechanical interaction between a patient's vertebrae, loading of implants, and other devices (e.g., rods, ties, brackets, plates, etc.) coupled to those implants. The output of these analyses can be used to select pedicle screw configurations, insertion trajectories, and placement location to optimize screw pull-out strength, maximum allowable loading (e.g., axial loads, shear loads, moments, etc.) to manage stresses between adjacent vertebrae, or maximum allowable stress in regions of the bone at risk for fracture. In some embodiments, a user could identify areas of weakened bone or areas on images of the patient where there is risk of a fracture due to the presence of a screw or other implant. This information can be provided to the virtual model. The virtual model can be used to evaluate whether the configuration or location of the implant would create an unacceptable risk of fracture in the identified region. If so, the system could alert the user to that risk or modify the implant configuration or the procedure to reduce the risk to an acceptable level. In other embodiments, the system could identify these areas of high fracture risk automatically. In yet another embodiment, the system could provide data to the user such as the maximum torque to apply to a given pedicle screw during the surgical procedure such that tissue trauma, risk of fracture, or adverse advents is minimized. At block856, method850can localize and classify areas of interest within the virtual model(s) from block854. This can be accomplished using object recognition that matches shapes of known objects to shapes within the virtual models. For example, in a virtual model for a spinal surgery, the images can be MRI images of vertebrae. The virtual vertebrae can be labeled (e.g. c1-s5) and virtual model vertebrae corresponding to the vertebrae for which the spinal procedure is planned can be selected as the areas of interest. In some implementations, additional areas around the selected areas can be added to the areas of interest, allowing the surgeon to select alternative options before or during the procedure. For example, the one or two vertebrae adjacent, on one or both sides, to the planned vertebrae can be additionally selected. At block858, method850can segment the areas of interest, identified at block856, to determine various boundaries and other features, such as the pedicle boundaries and the pedicle isthmus. In some implementations, the segmentation or boundary determinations can be performed using a machine learning model. The machine learning model can be trained, for the type of implant surgery to be performed, to receive a portion of a virtual model and identify target portion segmentations or boundaries. At block860, method850can localize an insertion point for the implant in the target area. In some implementations, this can be accomplished by applying a machine learning model trained to identify insertion points. In some implementations, localizing insertion points can be accomplish using an algorithm, e.g. that identify particular patterns, changes in color, shapes, etc. identified as corresponding to preferred implant insertion points. At block862, method850can compute an implant configuration based on the virtual model(s) and/or determinations made in blocks856-860. In some implementations, the implant can be associated with requirements for their application and properties to maximize or minimize. In these cases, the implant configuration can be specified as the configuration that fits with the virtual model, achieving all the requirements, and optimizing the maximizable or minimizable properties. For example, when method850is performed to determine pedicle screw configurations for a spinal surgery, virtual pedicle screws can be placed in a virtual model generated at block854, according to the insertion points determined at block860. The virtual pedicle screws can further be placed to: not breach cortical vertebral boundaries (e.g. determined at block858), with a specified amount of buffer, while maximizing the screw diameter and length, taking into consideration required buffers and close to optimal insertion angle, defined by the pedicle isthmus center and insertion point, for each vertebra (e.g. determined at block858). In some implementations, this placement of the implant can be performed as a constraint optimization problem. For example, a virtual screw can be placed inside the segmented vertebral body in the virtual model. The placement can then be adjusted until an equilibrium is reached that optimizes the parameters while conforming to the implant constraints. For example, method850can maximizing screw diameter and length while aligning with an optimal angle and avoiding cortical breaches. FIG.9illustrates a flowchart showing a method for training a machine learning model, according to an embodiment. Machine learning models, such as neural networks, can be trained to produce types of results. A neural network can be trained by obtaining, at block902, a quantity of “training items,” where each training item includes input similar to input the model will receive when in use and a corresponding scored result. At block904, the input from each training item can be supplied to the model to produce a result. At block906, the result can be compared to the scored result. At block908, model parameters can then be updated, based on how similar the model result is to the scored result and/or whether the score is positive or negative. For example, a model can be trained using sets of pre-operative MRI scans of vertebrae paired with pedicle screw placements used in the surgery and corresponding scores for the result of that surgery. The images can be converted to arrays of integers that, when provided to the machine learning model, produce values that specify screw placements. The screw placements can be compared to the actual screw placement used in the surgery that produced the training item. The model parameters can then be adjusted so the model output is more like the screw placement used in the surgery if the surgery was a success or less like the screw placement used in the surgery if the surgery was a failure. The amount of adjustment to the model parameters can be a function of how different the model prediction was from the actual screw configuration used and/or the level of success or failure of the surgery. As discussed above, machine learning models for the surgical assistance system can be trained to produce various results such as: to directly produce implant configurations upon receiving implant surgery information, to identify particular vertebral pedicles in various images, to determine an order or subset of images for processing, to localize and classify the target within an image, to segment target vertebrae, to determine boundaries or other features, to localize insertion points, etc. In various implementations, the training data for a machine learning model can include input data such as medical imaging data, other patient data, or surgeon data. For example, model input can include images of the patient, patient sex, age, height, weight, type of pathology, occupation, activity level, etc., specifics of implant systems (e.g. types and dimensions), availability of available implants, or aspects of a surgeon's preoperative plan (e.g. surgeon's initial implant configuration, detection and measurement of the patient's anatomy on images, etc.) In some implementations, model training data input can include surgeon specifics, such as statistics or preferences for implant configurations used by the surgeon performing the implant surgery or outcomes for implant usages. For example, surgeons may have better skill or experience with particular implant configurations, and the system can be trained to select implant configurations the particular surgeon is more likely to use successfully. The training data input can be paired with results to create training items. The results can be, for example, human annotated medical imaging data (as a comparison for identifications such as boundaries and insertion points identified by a model), human feedback to model outputs, surgeons' post-operative suggestion feedback (e.g. whether the surgeon accepted model provided recommendations completely, or made certain changes, or disregarded), surgeons post-operative operation outcome success score, post-operative images that can be analyzed to determine results, the existence of certain positive or negative patient results, such as cortical breaches or other complications that might have occurred in the procedure, overall level of recovery, or recovery time. In an illustrative embodiment, any of the operations, processes, etc. described herein can be implemented as computer-readable instructions stored on a computer-readable medium. The computer-readable instructions can be executed by a processor of a mobile unit, a network element, and/or any other computing device. There is little distinction left between hardware and software implementations of aspects of systems; the use of hardware or software is generally (but not always, in that in certain contexts the choice between hardware and software can become significant) a design choice representing cost vs. efficiency tradeoffs. There are various vehicles by which processes and/or systems and/or other technologies described herein can be effected (e.g., hardware, software, and/or firmware), and that the preferred vehicle will vary with the context in which the processes and/or systems and/or other technologies are deployed. For example, if an implementer determines that speed and accuracy are paramount, the implementer may opt for a mainly hardware and/or firmware vehicle; if flexibility is paramount, the implementer may opt for a mainly software implementation; or, yet again alternatively, the implementer may opt for some combination of hardware, software, and/or firmware. The foregoing detailed description has set forth various embodiments of the devices and/or processes via the use of block diagrams, flowcharts, and/or examples. Insofar as such block diagrams, flowcharts, and/or examples contain one or more functions and/or operations, it will be understood by those within the art that each function and/or operation within such block diagrams, flowcharts, or examples can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. In one embodiment, several portions of the subject matter described herein may be implemented via Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), digital signal processors (DSPs), or other integrated formats. However, those skilled in the art will recognize that some aspects of the embodiments disclosed herein, in whole or in part, can be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the subject matter described herein are capable of being distributed as a program product in a variety of forms, and that an illustrative embodiment of the subject matter described herein applies regardless of the particular type of signal bearing medium used to actually carry out the distribution. Examples of a signal bearing medium include, but are not limited to, the following: a recordable type medium such as a floppy disk, a hard disk drive, a CD, a DVD, a digital tape, a computer memory, etc.; and a transmission type medium such as a digital and/or an analog communication medium (e.g., a fiber optic cable, a waveguide, a wired communications link, a wireless communication link, etc.). Those skilled in the art will recognize that it is common within the art to describe devices and/or processes in the fashion set forth herein, and thereafter use engineering practices to integrate such described devices and/or processes into data processing systems. That is, at least a portion of the devices and/or processes described herein can be integrated into a data processing system via a reasonable amount of experimentation. Those having skill in the art will recognize that a typical data processing system generally includes one or more of a system unit housing, a video display device, a memory such as volatile and non-volatile memory, processors such as microprocessors and digital signal processors, computational entities such as operating systems, drivers, graphical user interfaces, and applications programs, one or more interaction devices, such as a touch pad or screen, and/or control systems including feedback loops and control motors (e.g., feedback for sensing position and/or velocity; control motors for moving and/or adjusting components and/or quantities). A typical data processing system may be implemented utilizing any suitable commercially available components, such as those typically found in data computing/communication and/or network computing/communication systems. The herein described subject matter sometimes illustrates different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely examples, and that in fact many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “operably connected”, or “operably coupled”, to each other to achieve the desired functionality, and any two components capable of being so associated can also be viewed as being “operably couplable”, to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and/or physically interacting components and/or wirelessly interactable and/or wirelessly interacting components and/or logically interacting and/or logically interactable components. All applications and patents referenced herein are incorporated by reference in their entireties. From the foregoing, it will be appreciated that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting.

11857265

DETAILED DESCRIPTION OF THE INVENTION Referring now to the figures, wherein like elements are numbered alike throughout, a surgical suite for computer assisted surgery is designated generally50. The suite50includes a first computer70for pre-operative use. For example, pre-operative analysis of the patient and selection of various elements may be performed on the first computer. The suite may also include a second computer80, referred to as the OR computer, which is used during a procedure to assist the surgeon and/or control one or more surgical instruments. In addition the suite may include a computer (standalone or collaborating with80) mounted on the surgical instrument. First computer70is provided in the present instance, but may be omitted in some configurations because the functions of computer70are also implemented on OR computer80, which can be a standalone. Moreover the whole ‘pre-surgical planning’ may happen instantaneously inside the OR. Nevertheless, if desired for particular applications, first computer70may be used. Furthermore, the micro-processing system of the system50can reside in the cutting instrument. In such a configuration, the computations and user interface can be performed within a computer on the surgical tool. Such system performs error analysis of location of the cutting instrument relative to the ideal cut to be performed, and displays corrective actions and other information on a screen mounted to the instrument. The suite50may include a tracking/navigation system that allows tracking in real time of the position in space of several elements, including: (a) the patient's structures, such as the bone or other tissue; (b) the navigable surgical tools, such as the bone saw100, which is controlled by the surgeon based on information from the OR computer80or (c) surgeon/assistants system specific tools, such as a pointer, registration tools, or other objects. The OR computer80may also perform some control on the cutting instrument trough the implemented of the present configuration of the system. Based on the location of the tool, the system80is able to vary the speed of the surgical tool100as well as turn the tool off to prevent potential damage. Additionally, the suite50may also include a surgical robot200that is controlled by the OR computer80. The features of the navigable tool100and the surgical robot200may vary. The details of several desirable features are described in greater detail below. The various features can be selected as desired for a particular practice or situation. In the following description, the only surgical instrument shown in figures is the navigated saw100. Nonetheless, many others instruments can be controlled and/or navigated as explained above, such as a drill, burr, scalpel, stylus, or other instrument. Therefore in the following discussion, the system is not limited to the particular tool described, but has application to a wide variety of instruments. As discussed further below, one exemplary use of the surgical suite incorporates the use of a virtual model of the portion of the patient upon which a procedure is to be performed. Specifically, prior to a procedure, a three dimensional model of the relevant portion of the patient is produced using CT scans, MRI scans or other techniques. Prior to surgery, the surgeon may view and manipulate the patient model to evaluate the strategy for proceeding with the actual procedure. One potential methodology uses the patient model as a navigation device during a procedure. For instance, prior to a procedure, the surgeon may analyze the virtual model of a portion of the patient and map out the tissue to be resected during a procedure. The model is then used to guide the surgeon during the actual procedure. Specifically, during the procedure a tracking mechanism monitors the progress of the procedure and the results are displayed in real time on the OR computer80so that the surgeon can see the progress relative to the patient model. Referring toFIGS.1-2, to provide navigation assistance during a procedure, the system50includes a position detection device120that monitors the position of the surgical tool100. The surgical tool100includes one or more position markers105that identify pre-defined points of reference on the tool. In the present instance the surgical tool includes several markers105which, together with some pre-defined points of reference on the tool, identify the tool and its location. Although a variety of position tracking systems can be used, one exemplary system is the NDI Polaris optical measurement system produced by Northern Digital Inc. The system uses a position sensor and both active and passive markers. The active markers may be wired sensors that are electrically connected to the system. The active markers emit infrared light that is received by the position sensor. The passive markers are wireless markers that need not be electrically connected to the system. The passive markers reflect infrared light back to the position sensor. Typically, when using passive markers, the position sensor floods the field of view with infrared light that is then reflected back to the position sensor from the passive markers. The position sensor includes an infrared receiver and it receives light emitted light from the active markers and reflected light from the passive markers. The position system triangulates the three dimensional position of the tool based on the position of the markers. In the present instance, the position detection device120is also operable to detect the orientation of the tool relative three orthogonal axes. In this way, the position detection device120determines the location and orientation of the tool100. The position detection device120is linked with the OR computer80so that the data regarding the position of the surgical tool100, the patient's anatomy, and other system specific tools, is communicated to the OR computer. The computer uses this information to track the progress of a procedure. To track the position of the surgical tool100relative to the patient, a position marker is attached to the portion of the patient on which the procedure is to be performed. The position marker attached to the patient may be similar to the position marker105attached to the surgical tool100, as shown inFIG.4. The position marker on the patient is correlated to a corresponding point on the virtual model of the patient. In this way, the registration point positions the tool relative to the patient and the patient relative to the virtual model. A series of points are used to register or correlate the position of the patient's anatomy with the virtual model of the patient. To gather this information, a navigated pointer is used to acquire points at an anatomical landmark or a set of points on a surface within the patient's anatomy. A process referred to morphing may be used to register the patient to the virtual model of the patient. During such a process, the surgeon digitizes parts of the patient and some strategic anatomical landmarks. The computer80analyzes the data and identifies common anatomical features to thereby identify the location of points on the patient that correspond to particular points on the virtual model. Accordingly, as set forth above, the position detector monitors the position of several items in real time, including: the position of the surgical tool100, the position of the patient and the position of items used during a procedure, such as a pen or marker as described further below. Accordingly, the computer combines the data regarding the position of the surgical tool100, the data regarding the position of the patient, and the data regarding the model of the patient. This combination is used to provide a real time model of the position of the tool relative to the patient, which can be viewed by the surgeon on the monitor. Further still, as previously described, prior to a procedure, the surgeon may analyze the patient model and identify the tissue that is to be resected. This information can then be used during the procedure to guide the surgeon. During the procedure, the monitor displays a model of the surgical tool relative to the patient model, which reflects the real time position of the tools, such as the surgical tool100, relative to the patient. The surgeon can align the position of the tool100by viewing the position of the image of the tool relative to the patient model on screen. Once the monitor shows the virtual tool to be aligned with the portion of the patient model identified for resection, the surgical tool is properly aligned on the patient. In this way, the doctor can align the tool without the need for complex jigs or fixtures. Further, as the tool100intersects the patient, the data regarding the position of the tool and the patient model is correlated to show the result of the tool intersecting the patient. In this way, the computer can analyze and display the progress of a procedure in real time. As the tool100cuts patient tissue, the monitor displays the tissue being removed from the patient model. Therefore, in addition to guiding the position of the tool, the OR computer can be used to guide the surgeon as to what tissue should be resected during a procedure. In addition to including a surgical tool controlled by the surgeon, the suite50may include a surgical robot200. The surgical robot can be programmed to perform one or more operations during a medical procedure. The surgical robot200is controlled by the OR computer, which is programmed with the instruction set for the procedure. As with the navigation system described above, when using the robot, the position detection device120monitors the position of the surgical robot, and prior to the procedure the location of the patient is identified so that the computer has data regarding the position of the surgical robot relative to the position of the patient. Controlling the Selection of View As previously discussed, information regarding the position of the surgical instrument can be combined with a model of the patient to guide the surgeon during a procedure. During a particular step in a procedure, the surgeon may desire to see a particular view or perspective with a certain combination of orientations of the patient model and the instrument, as well as two dimensional projections. For example when making planar bone cuts using an oscillating bone saw, the system may show simplified two dimensional views along with a three dimensional view. The simplified two-dimensional diagrams may be similar to those displayed on aircraft cockpits or flight simulators, which help align the cut and correct roll and pitch of the saw relative to the plane to be cut. Such diagrams dynamically update in real time and can be shown on the main display of the system and/or a secondary screen, including one mounted on the cutting instrument itself. Although a surgeon may desire to have control over the view, the surgeon normally does not want to be encumbered by manipulating system controls during a procedure. Accordingly, the system is configured to quickly and efficiently automatically change the relevant views and perspectives of the surgical scene. Additionally, the system allows the surgeon to manually select any view/perspective the surgeon may desire. In the present instance, the system is operable in three modes:a) manual view selection;b) pre-set view selection; andc) automatic view selection. Each of these is described further below. Manual View Selection In the manual view selection mode, the surgeon selects from among numerous parameters to define the exact view that the surgeon desires. The parameters include: the orientation (therefore perspective) of the 3D surgical scene as rendered on the computer screen in the form of an “image”, the orientation of the patient model, the surgical instrument to be illustrated, the zoom ratio of the image, the panning position of the image, the transparency of the patient anatomy models, the transparency of the surgical instrument, and the coloring of various items on the screen. These parameters are only examples of the types of parameters that that the surgeon can control to define a view. The system may include many other parameters that the surgeon can control. In the manual view selection, the surgeon selects and adjusts one or more of the parameters to define the view. For example, the system may include controls to rotate the image about one or more axes. The surgeon may rotate the image through varying degrees about one or more axes to display a particular orientation to see a particular feature of the patient. In this way, the surgeon can precisely define the orientation of the image. In addition to controlling the image orientation, the surgeon can control any other parameter to define a view. The system may include a variety of input devices in addition to or instead of a typical computer mouse and/or keyboard to allow the surgeon to enter the information to define the parameters for a particular view. For instance, the view screen may be a touch screen and the surgeon may enter the information through one or more menus. Alternatively, the system may include a voice recognition element so that the surgeon may enter the parameters by voice. Further still, the surgical instrument itself may be configured with controls that can be used to enter information regarding one or more of the parameters. In short, the system may include one or more of a variety of interfaces to allow the surgeon to input information to control the parameters that define a view. Pre-Set View Selection Although the manual view selection mode provides precise control of the various parameters that define the view for an image, the manual mode can be cumbersome if the surgeon must manually define the parameters for each view during a procedure. To make the view selection easier for the surgeon, the system may also include a pre-set view selection mode. In the pre-set view selection, the surgeon selects a view from a list of pre-set views. A pre-set view is one in which the parameters that define a view have been previously selected. The pre-set views are either programmed as defaults for the system, or are added as custom views by the user. For instance, a pre-set view may show the patient model in a particular orientation or perspective at a particular zoom and pan, with a particular bone transparency and coloring. Since the parameters are pre-set, the surgeon can simply select a pre-set view to see the image model. In this way, the surgeon can easily select from a number of views to quickly and easily view the patient model under a variety of conditions. By way of a simple example, in the case of a procedure to implant a knee prosthetic, the pre-set views may include a set of views of the femur, such as an anterior view, a posterior view, a medial view, a lateral view, and a distal view. The surgeon can quickly select from among these orientations simply by selecting one of the pre-set views. In this example the views are defined by the orientation of the patient model, however, each pre-set view includes a number of pre-set parameters (such as a suitable pan, zoom, relative transparency of the different objects, etc), the combination of which is designed to provide an optimized graphical environment for a particular bone preparation/cutting part with the surgical instrument, bone cut assessments, measurements, etc. As described above, the system may include a variety of different elements to allow the surgeon to select those parameters for the view. For instance, the system can use computer voice recognition or a touch screen or controls mounted directly on the surgical instrument to input data regarding the view. Any of these or other input mechanisms can be used to allow the surgeon to select a pre-set view. After the surgeon has selected a pre-set view, the surgeon may then manipulate one or more parameters to alter the view. Referring again to the list of pre-set views for a knee procedure, the surgeon may select an anterior view that illustrates, for example, the front of the femur. The pre-set view may be defined such that the patient model is illustrated at 100% magnification. After selecting the pre-set view the surgeon may alter the view to increase the zoom to 200% magnification. The surgeon can make this change using any of a variety of controls that the system may include, as discussed above. In the present instance, the system also includes the ability to add a view to the list of pre-set views. For example, as described above, the surgeon can use the manual view selection mode to define a view and then save the view as a pre-defined view. Similarly, the surgeon may select a pre-set view and alter one or more parameters to create a new view. The surgeon may then save the new view as an additional view. For instance, as described above, the surgeon may select a pre-set view entitled anterior view to show the front of the femur. After increasing the magnification of the pre-set view to 200%, the surgeon may choose to save the new view as “enlarged anterior view”. Therefore, the surgeon can readily bring up the anterior view with the magnification at 200% simply by selecting the view entitled “enlarged anterior view”. Although this example demonstrates how a pre-defined view can be created to provide a view with a different magnification, it should be appreciated that a new view may be defined having whatever combination of parameters the surgeon desires. Automatic View Selection Although the pre-set view mode makes it easier for a surgeon to select a desired view during a procedure, the surgeon must still take the step of selecting the view that the surgeon wants displayed. Since a surgeon normally will frequently switch among various views during different steps of a procedure, it may be desirable to provide an easier way of switching the view during a procedure. Therefore, the system may also include a mode in which the view is automatically selected by the computer depending on what part of the bone preparation process the surgeon intends to perform. In the automatic view selection mode the system automatically selects which view to show based on the current location of the surgical (or measuring) instrument relative to the bone. Specifically, as discussed previously, the system includes a mechanism for tracking the location of the surgical instrument relative to the patient. In response to the data regarding the position of the surgical instrument relative to the patient, its previous location, its approach to a new location and its motion, the system determines what the surgeon is attempting to do. The system then determines the appropriate/optimal view, and shows the view on the display. Referring again to the example of the knee procedure discussed above, if the surgeon positions the surgical instrument so that the cutting blade is close to the anterior portion of the femur and the plane of the blade of a cutting saw is approaching parallel to one of the desired planar cuts (such as the anterior cut), the system will detect the proximity of the instrument relative to the patient, and the orientation of the blade relative to the patient. Based on the proximity, orientation, and approach of the instrument to the anterior portion of the femur, the system will select the optimum view for this cutting process and show that view on the view screen. In this case that optimum could be (but not limited to) a sagittal view (lateral or medial) of the femur with pan, zoom and other transparency settings of bone and blade to focus on the anterior cut being performed. If the surgeon moves the surgical instrument so that the cutting blade is approaching closely and in the right orientation to perform the posterior cut of the femur, the system will sense the change in position and change the view to show the view appropriate for that specific cut. Although the system has been described as automatically selecting a view in response to the position of the surgical instrument, other data can be incorporated into the determination of the view that is automatically selected. The additional data may be information input into the system by the surgeon or otherwise. For example, referring again to the knee example, the surgeon may prefer to see the “enlarged anterior view” when the surgical instrument is adjacent the anterior portion of the femur rather than the default “anterior view”. Therefore, the surgeon may input information directing the system to use the “enlarged anterior view” instead of the default “anterior view”. Accordingly, during the procedure, when the surgical instrument is adjacent the anterior portion of the end of the femur, the system determines that the “enlarged anterior view” should be shown. This determination is made based on the combination of the data regarding the position of the surgical instrument and the data regarding the preferences of the surgeon. Since the system can account for the preferences of a surgeon, it is desirable to store the preferences for each surgeon in a user profile. As a surgeon saves pre-set views, the data regarding those pre-set views are added to a user profile for the surgeon and attributed or mapped to the exact types/steps of the procedure. Therefore, prior to performing a procedure, the surgeon selects the appropriate user profile and the data regarding the surgeon's preferences is loaded into the system. In the foregoing discussion, the surgeon took the effort to input the data regarding the preferences. Alternatively, the system may track a surgeon's usage to learn the preferences of a surgeon. This data is then used to control the image viewed during the automatic view selection mode. Specifically, the system can track data that is generated during a procedure and identify data that affects the view desired by a surgeon. One way that the system can track usage data is to identify correlations between the position of the surgical instrument and input received from the surgeon regarding the desired view. For example, as discussed above, a surgeon may routinely switch to an enlarged view when the surgical instrument is adjacent the anterior portion of the femur. By tracking the data regarding the relative position of the surgical instrument and the input from the surgeon regarding the desired view, the system can learn that the surgeon desires to see an enlarged view when the surgical instrument is adjacent the anterior portion of the femur. Therefore, during a procedure, when the user profile for the surgeon is loaded into the system, the system automatically displays an enlarged anterior view rather than the default anterior view when the surgical instrument is adjacent the anterior portion of the femur. The above example illustrates how the system can track data regarding a surgeon's use to automatically change the perspective/orientation of the scene, its pan, and zoom ratio of an image during automatic view selection mode. It should be understood however, that this is just a simplified example to illustrate a few parameters that the system can track to learn a surgeon's preferences. In actual practice, the system may track data regarding any number of the various parameters that the surgeon may control during a procedure. By tracking and processing the data, the system can learn various data about a surgeon usage. This data is indicative of a surgeon's preferences. By storing and using this data, the system can learn a surgeon's preferences and use the data regarding the preferences to control the image displayed during the Automatic View Selection mode. The data-set representing a given surgeon's user profile for a certain procedure can be transformed/loaded to be used for another surgeon should they desire this, and if they have permission. This is useful in training; to provide the know-how from expert surgeons to novice surgeons. The preferences of which exact views (and all detailed parameter combinations) to use during a given step of a surgical procedure can help novice surgeons start from an optimized set of views and improve upon them to suit their individual preferences. In case of a newer user of the system who has not defined preferences, the system will provide a default standard set, which is based on experiments and the experience of other surgeons collected by the developers of the system. As explained above, this default set can be modified/customized/enhanced afterwards by the new user. Bone Removal Simulation and Graphical Identification of Regions As described previously, the present system50can be utilized to perform guided freehand surgery. Specifically, a virtual representation or model of a portion of a patient is provided, along with a model of the surgical tool to guide the surgeon during a procedure. The patient model may include a portion identified as tissue to be resected or otherwise operated on during a procedure. The system tracks the movement of the surgical tool100, so that when the surgeon moves the tool, the system displays the movement of the tool in real time on a monitor, along with showing the removal of tissue that is resected in response to the movement of the tool. Accordingly, the surgeon can align the tool with the patient by aligning the model of the tool with the portion of the patient model identified for resection. Therefore, the surgeon can follow the onscreen guidance to resect a portion of tissue. The system may be configured to include various improvements to the processing and graphical representation of the patient model to improve the guidance and/or assistance that the system provides to the surgeon. For instance, various regions of the patient model may be graphically represented in different ways to aide the surgeon in viewing the patient model. One way the system can do this is to display different portions of the patient model in different colors. The different portions of the model are selected and assigned the various colors based on the procedure to be performed, as well as variables that are controllable by the surgeon. In one example, the system identifies various regions of a patient model based on a prosthetic to be implanted into a patient. The region to be resected will be determined based on the configuration of the prosthetic, variables specific to the procedure (e.g. whether the implant is to be cemented or not), and preferences of the surgeon that may be input into the system or stored in a user profile. Based on these and/or other variables, certain regions of the patient model may be identified as tissue to be resected. Certain other regions may be identified as tissue that may be resected; and certain other regions may be identified as tissue that should not be resected. By identifying the various regions of the patient model, the system can use this information to display the patient model in a manner that improves the surgeon's ability to process the graphical data. For instance, the regions of the virtual model representing tissue that should be resected can be illustrated in a first color, such as green, The regions of the virtual model representing tissue that may be resected, but do not need to be resected, can be illustrated in a second color, such as yellow. The regions of the patient model representing tissue that should not be resected can be illustrated in a third color, such as red. There could also be a gradient applied to the transitions from the boundary of one region to the boundary of the adjacent region. The color gradient would create a gradual change in color from one region to the next. For instance, the boundary area between the green region and the yellow region may be colored to follow a color gradient from green to yellow. The color gradients aide the surgeon in identifying transitions from one region to another. Alternatively, the different regions may be represented by uniform colors without color gradients between regions. In some instances, the use of uniform colors rather than color gradients can create a contrast that provides an alignment aide for the surgeon to use. The surgeon may align the surgical tool with a plane represented by the intersection of two regions. The color contrast of the different regions may create an easy to read graphical representation that the surgeon can use for alignment. In addition to providing alignment, the difference in color between the regions serves as an indication to the surgeon to proceed more slowly as the tool approaches the resection boundary. When resecting a portion of a bone a surgeon may cut more rapidly and aggressively when the cutting tool is relatively far from the boundary of the area to be resected. As the surgeon approaches the boundary of the resection area, the surgeon may slow the pace of cutting to ensure that the resection remains within the desired boundaries. By illustrating the different regions in different colors (or otherwise), the system provides a readily identifiable graphical display that informs the surgeon of the proximity of the surgical tool to a resection boundary. Similarly, the system can be used to identify the proximity of the surgical tool to sensitive anatomical structures, such as nerves, vessels, ligaments etc. The anatomical structures can be illustrated in red and the tissue proximate the structures can be identified in yellow as an indicator to the surgeon that the cutting tool is getting close to the sensitive structure. As discussed above, the contrasts between different representations of different regions of a patient model can be helpful to guide the surgeon in aligning the surgical instrument during a procedure. To further improve the alignment of the surgical instrument with a particular plane, the graphical representation of the surgical instrument may be altered. More specifically, the boundaries of the surgical instrument may be elongated along a line or along an entire plane. For instance, in the case of a bone cutting saw, the blade is a generally rectangular thin flat blade having a height, length and thickness or gauge. The thickness is normally the smallest of the three dimensions. When viewing the model of the blade on edge, the edge of the blade will generally look like a thick line. To improve the guidance provided to the surgeon, the height and length of the blade may be elongated. By elongating or enlarging the representation of the blade, the surgeon can more easily identify the plane of the blade to ensure that the plane of the blade is aligned with the proper plane for a cut. The extensions are particularly helpful in illustrating whether the cutting blade is rotated relative to a desired plane. The graphical extensions for the blade may be illustrated in the same color and style as the blade. In the present instance, the graphical extensions have some characteristics that are similar to the surgical instrument, but there are one or more characteristics that differ. For example, in the present instance, the cutting tool may be displayed on the screen as an opaque yellow item. The extensions may be a similar color but they may be semi-transparent, so that the surgeon can easily recognize that the extensions are related to the blade, while also easily distinguishing which part represents the cutting tool and which part represents the extensions. The system may provide controls to allow the surgeon to control characteristics of the extensions, such as the extent of the extensions (i.e. how much elongation along the height, how much elongation along the length), the color of the extensions and the opacity of the extensions, as well as other characteristics. The controls also allow the surgeon to manually turn the extensions on and off. In addition to manually controlling the characteristics of the extensions, the characteristics of the extensions may be defined by pre-set views. The operation of pre-set views are described in detail above. As an example of controlling the extensions using pre-set views, in a first pre-set view, the extensions may be illustrated in a certain manner with a certain color and opacity. In a second pre-set view, the extensions may not be displayed at all. By switching between the first and second pre-set views, the surgeon can control the display of the extensions. Further, as discussed above, the system may be configured to automatically change between pre-set views based on the location and/or orientation of the surgical instrument. Therefore, the pre-set views can be defined so that the extensions are automatically turned on or off depending on the location and/or orientation of the surgical instrument. As an alternative to illustrating the extensions as simply planar extensions, the cutting tool and/or extensions cutting blade may be illustrated as an oval on the display. The shape of the cutting blade then depends on the angle of the cutting blade relative to the proper plane. If the cutting blade is aligned properly, the cutting blade will look similar to a line. As the cutting blade is twisted relative to the proper cutting plane, the cutting blade appears more rounded and oval. In this way, the variation between the angle of the cutting blade and the angle of the proper cutting plane is readily apparent based on the ovality of the cutting tool on the display. The option of displaying the blade as an oval is another choice that can be selected for a particular view. Therefore, in one view, the blade may be illustrated without any extension. In another view, the blade may be illustrated with planar elongations. In yet a third view, the blade may be represented as an oval. The surgeon may switch between these representations within a view, or the representations may be defined in one or more pre-set views. In the description above, different regions of the patient model are identified and are illustrated differently to aide the surgeon during a procedure. In addition to providing a graphical representation of the different regions, the system may use the data regarding the different regions to provide a graphical and/or audible warning to the surgeon. For instance, as the system detects the surgical tool approaching the area proximate the resection boundary (e.g. the yellow zone), the system may display a graphical warning on the monitor85in addition to illustrating the surgical tool in the yellow zone of tissue on the model. Alternatively, or in addition to the graphical warning, the system may provide an audible warning indicating that the cutting tool is approaching the desired boundary. The system may provide yet another warning in the event the cutting tool is detected at or beyond the desired boundary. In other words, if the surgical tool enters the red zone the system may provide a further warning. In addition to providing warnings, the system may be configured to control the operation of the surgical tool in response to the position of the surgical tool relative to the desired boundary. Specifically, if the system determines that the tool is positioned within the tissue to be resected (e.g. in the green zone), the system may allow the surgical tool to be controlled as desired by the surgeon. If the system determines that the tool is positioned within the tissue that may be resected but is near the tissue that is identified as tissue that should not be resected (e.g. the yellow zone), the system may reduce or attenuate the operation of the surgical tool. For instance, if the tool is a saw, and it enters the yellow zone, the system may slow down the reciprocation of the saw as it moves close to the resection boundary. Further still, if the system detects that the tool is positioned at the boundary or in tissue that is not to be resected, the system may completely stop the tool. Although the system may automatically control the operation of the surgical tool, the system includes an override function that allows the surgeon to override the control of the tool. In this way, if the surgeon determines that a portion of tissue should be resected that was not previously identified for resection, the surgeon can override the system and resect the tissue during the procedure. In the discussion above, the system controls the display of various regions based on an identification of the regions prior to a procedure. The system may also allow regions to be identified and/or re-assessed during a procedure. For instance, as described in the section regarding assessment of bone preparation, the system may include features relating to assessing the cuts made during a procedure to determine whether further cuts need to be made. In response to the assessment, the system may determine which portions of the bone need to be cut to correct an inaccuracy in a resection procedure. This correction assessment may cause a change in the regions of the patient to be resected, which will cause a change in the identification of various portions of the patient model. For example, a region that was initially identified as a yellow region may be changed to a green region after the correction assessment. In this way, the identification of regions of a patient model may change during the course of a procedure. In the foregoing description the operation of the surgical instrument is controlled based on the region in which the instrument is operating. Additionally, the operation of the surgical instrument may be controlled based on how far into a region the instrument has traveled. For instance, the surgical instrument may not need to be significantly attenuated when it just enters the yellow region. However, the instrument may need to be significantly attenuated if it advances significantly through the yellow region toward the red region. Accordingly, the magnitude of control may relate to both the region that the instrument is positioned within and the degree to which the instrument extends into the region. Navigated Marking Pen As described previously, the OR computer80may display a virtual model of the portion of the patient on which the procedure is to be performed. In the discussions above, the patient model was utilized to guide the surgeon in manipulating surgical tool to perform a procedure. The following discussion describes how the patient model can be used to guide the surgeon in preparing the site for a procedure. Specifically, the system may guide the surgeon in marking lines on the patient to identify cut lines etc. for a procedure. The markings on the patient can then be used alone or in combination with the guided freehand procedure described above. Referring toFIG.13, a navigated marking pen250is illustrated. The marking pen250includes one or more elements for detecting the position and orientation of the marker. For instance, the marking pen may include a reference frame257and a plurality of position markers255similar to the frame107and position markers105described above in connection with the surgical tool. The marking pen250can be guided by viewing the display of the OR computer80as described above in connection with operation of the surgical tool100. The marking pen250is guided to draw lines on the bone at the appropriate locations as identified on the virtual model. The method for using the navigable marking pen250operates as follows. Prior to the procedure, a virtual model of the relevant portion of the patient is created as discussed above. The surgeon analyzes the patient model to determine the procedure to be performed and identifies the portion of the patient to be resected or otherwise operated upon during the procedure. For instance, in the instance of implanting a prosthetic device, a femoral prosthetic may be implanted. The surgeon selects the appropriate prosthetic and aligns a model of the prosthetic over the operation site. Based on the model of the prosthetic and the alignment, the Pre-op computer70may identify the tissue to be resected during the procedure. Prior to the procedure, the patient is registered as described previously, so that the patient position corresponds to the patient model. The OR computer80displays the patient model, identifying the tissue to be resected, and the position of the marking pen is also illustrated on the display. As the surgeon manipulates the marking pen250, the position detection device120detects the movement of the marking pen and provides data to the OR computer so that the model of the marking pen moves on the screen relative to the patient model in real time. Accordingly, the surgeon manipulates the marking pen so that the model of the marking pen aligns with the portion of the virtual model indicated for resection. The surgeon manipulates the marking pen250so that the model of the marking pen traces the area of the virtual model identified for resection or other procedure (such as drilling). In this way, the virtual model provides a guide for guiding the surgeon to mark the appropriate areas on the patient on which the procedure is to be performed. The surgeon may then simply perform the procedure freehand using the markings on the patient as a guide or the surgeon may perform the procedure using the markings and also using freehand navigation assistance as described above. FIG.13also illustrates another potential improvement, in that the marking pen250may include a retractable pen that retracts when the marking pen is not aligned with the proper area on the patient. By retracting, it is much less likely that the surgeon may mark an incorrect area. As shown inFIG.13, the marking pen250includes a hollow housing260having a generally open forward end. A displaceable pen275is disposed within the hollow housing260. The pen is displaceable between an extended position and a retracted position. In the extended position the tip of the pen extends from the housing so that the tip of the pen can be used to mark a surface. In the retracted position the pen is retracted into the housing so that the forward tip of the pen is within the housing so that the pen cannot mark a surface. A spring285connected to the pen275biases the pen toward the retracted position. An actuator280, such as a solenoid is operable to extend the pen forwardly against the bias of the spring. Specifically, when the solenoid is energized, the solenoid drives the pen to the extended position. When the solenoid is de-energized, the spring285retracts the pen into the housing. Alternatively, the solenoid can be configured to drive the pen in both directions, i.e. the solenoid can drive the pen forwardly and rearwardly as desired. The marking pen250is in communication with the OR computer80to receive signals indicating whether the pen275should be extended or retracted. The marking pen may include a wired connection to the OR computer, however, in the present instance, the OR computer80includes a transmitter, and the marking pen includes a wireless receiver for receiving signals from the computer. The marking pen250includes a processor270for receiving the signals from the computer and controlling the extension and retraction of the pen275in response to the signals. Specifically, the processor270controls the operation of the solenoid to selectively energize and de-energize the solenoid in response to signals received from the OR computer. The operation of the retractable marking pen250is similar to the operation described above. However, the OR computer correlates the data from the virtual model with the data regarding the position of the marking pen. If the OR computer determines that the marking pen is positioned over a portion of the patient that should be marked, the computer transmits a signal to the marking pen250indicating that the pen should be extended. The marking pen receives the signal and the processor270controls the solenoid, thereby energizing the solenoid to extend the pen tip275. If the OR computer determines that the marking pen is positioned over a portion of the patient that is not to be marked, the computer transmits a signal to the marking pen indicating that the pen should be retracted and the processor controls the solenoid to retract the pen. Alternatively, the processor may be configured so that the solenoid is energized only as long as the controller receives a signal indicating that the pen should be extended. In this way, the OR computer sends a signal to the marking pen as long as the computer determines that the marking pen is over a portion to be marked. As soon as the computer determines that the marker is over an area that is not to be marked, the computer ceases sending a signal to the marking pen. The processor then de-energizes the solenoid to retract the pen in response to the lack of signal. As an alternative to a retractable tip, the marker may use an inkjet, rather than a regular marker tip. Rather than controlling the extension or retraction of the marker tip, the ejection of the ink through the inkjet is controlled. Specifically, when the marker is over a portion of the portion of the patient to be marked, the marker may be enable so that ink may flow through the inkjet. However, when the marker is over a portion of the patient that is not to be marked, the marker is disabled, so that the flow of ink to the inkjet is shut off. As can be seen from the foregoing, the marking pen250can provide an accurate and efficient method for marking cut lines and other marking lines for performing a procedure. Prior to the procedure, the surgeon may utilize the guidance system to manipulate the marking pen by aligning the model of the pen with the area of the virtual model to be operated on. While the surgeon maintains alignment of the virtual pen with the portions of the model indicated as proper marking lines (such as the outline of a prosthetic), the OR computer sends a signal to the marking pen indicating that the pen element275should be extended. As the surgeon maintains the virtual pen aligned on proper parts of the virtual model, the marking pen250marks the patient. If the surgeon manipulates the pen so that the virtual pen moves out of alignment with the proper parts of the virtual model, the OR computer sends a signal to the marking pen (or ceases sending a signal to the pen as described above), and the pen tip275retracts into the housing so that the pen stops marking the patient. In this way, the surgeon controls the retraction of the pen by maintaining alignment of the virtual pen with the portion or portions of the model that were identified as portions to be marked. Registration Pointer with Surface Contact Detection Prior to or during a procedure, a digitizing pen or pointer may be used to identify the location of points of reference on a patient. Similarly, the pointer may be used to mark areas to identify a surface. The marked points identify the location of discrete points or areas on a patient to correlate or register the patient model with the actual position of the patient. Although a pointer can be helpful in registering the location of a patient, human error can lead to errors in properly registering the patient location. For instance, when the surgeon is tracing the surface of the patient tissue, the tip of the pointer may come out of contact with the surface of the tissue. This is particularly true when tracing over soft tissue or when tracing along curved surfaces. If the pointer is not in contact with the surface of the tissue, the resulting data points will be erroneous. To improve the accuracy of the data collected during registration, the system may include a pointer that incorporates a sensor that detects whether the pointer is in contact with the patient tissue. If the pointer is out of contact with the surface of the relevant portion of the patient, the points are ignored during the registration analysis. Additionally, the system may provide feedback to the surgeon to warn the surgeon that the point is out of contact with the patient tissue. Referring toFIG.15, an improved registration pointer is designated350. The pointer is an elongated element having a tip configured to contact the relevant portion of a patient. The pointer350is operatively linked with the position detection device120. The operative link may be a wireless connection in which the pointer includes a wireless transmitter. Alternatively, the pointer may be connected directly to the detection device via a cable. The pointer includes a sensor360for detecting whether the tip of the pointer is in engagement with the patient or whether the tip of the pointer is spaced apart from the patient. One possible sensor360is an impedance sensor. Alternatively, the sensor may be a simple force transducer. The pointer350includes a circuit365for analyzing the signal from the sensor and determining whether the pointer is in contact with the patient surface based on the signal from the sensor. The data for the point or points in which the pointer was out of contact with the patient surface are not utilized during the registration process. Specifically, the pointer circuit may identify valid and invalid data by various means. According to a first method, the pointer communicates the relevant data to the OR computer80via a wired or wireless connection. Alternatively, the pointer circuit may control the position tracking elements so that the pointer is out of view of the position detection device120when the pointer350is out of contact with the patient surface. According to the first method, the OR computer receives signals from both the pointer350and the position detection device120and processes the data. The pointer circuit provides a signal to the OR computer indicating whether the pointer is in contact with the patient tissue. The OR computer80receives the signals from the pointer circuit365along with signals from the position detection device120that indicate the position of the pointer. Based on the signal received from the pointer350, the OR computer80either accepts or rejects the position data received from the position detection device120. For instance, if the surgeon is tracing the pointer over an area of tissue, the OR computer will accept the position data regarding the area traced by the pointer as long as the sensor360detects that the pointer tip is in contact with the patient. If the sensor360detects that the pointer is out of contact, the OR computer discards or rejects the data from the position detection device120corresponding to the positions that the sensor detected the pointer is out of contact. In this way, as long as the pointer remains out of contact with the patient surface, the OR computer discards the corresponding position data from the position detection device. The system may be configured to process the signals from the pointer350and the position detection device120in a variety of ways. For instance, the OR computer may reject data from the position detection device unless the pointer sensor360provides a signal indicating that the pointer is in contact with the patient tissue. Alternatively, the OR computer may accept data from the position detection device unless the pointer sensor360provides a signal indicating that the pointer is out of contact with the patient tissue. In either alternative, the OR computer only records data for points in which the pointer is in contact with the patient tissue. In an alternative embodiment, the OR computer does not reject the data to eliminate erroneous data. Instead, the system alters the position detection device120to prevent the erroneous points from being detecting. Specifically, the system controls features of the position detection device120to essentially make the pointer disappear from view of the position detection device when the pointer is out of contact. Since the pointer is out of view when it is out of contact with the patient, no data is collected while the pointer is out of contact. The steps for rendering the position detection elements out of view of the detector varies depend on the type of detection element. For instance, as described previously, the position detection device may operate in conjunction with passive and active markers. An active marker is a marker that transmits an infrared signal to the detection device and the position of the marker is identified by triangulating the received signal. Accordingly, to control the active marker(s), the pointer circuit365controls the active markers by turning off the active markers so that they no longer emit an infrared signal when the pointer is out of contact with the relevant portion of the patient. When the emitter ceases emitting infrared light, the marker is hidden from the position detection device120so that the registration points are not detected. If the markers on the pointer are passive elements, the markers are detected by detecting the infrared light reflected back to the position detection device120. In order to hide such passive markers the pointer circuit may be used to control one or more elements including a displaceable opaque surface and an electronically/chromatically actuated effect to disable the infra-red reflectivity of the ball. Accordingly, for both passive marker systems and active marker systems, the system may control the position detection device120in response to signals from the pointer350indicating that the pointer is out of contact with the patient tissue. In addition to controlling whether or not data points are accepted or rejected, the system may provide feedback to the surgeon warning that the pointer is out of contact with the patient tissue. For instance, if the sensor360on the pointer350indicates that the pointer is out of contact with the patient tissue, the pointer circuit365may provide a signal to an indicator light, such as an LED on the pointer. Therefore, if the surgeon sees the LED illuminated, the surgeon will recognize that the pointer needs to be pressed against the patient. Alternatively, the signal from the sensor circuit can be communicated with the OR computer, so that a warning is displayed on the display screen. In addition to providing a visual warning, the system may provide an audible warning. Specifically, the pointer circuit365may provide a signal to an audio element to provide a warning signal, such as a beep when the pointer is out of contact with the patient. There may be instances in which the pointer is out of contact with the patient so often that it may be desirable to re-start the registration process. Accordingly, the system may track the number of times that the sensor360detects that the pointer is out of contact with the patient. If the number of times exceeds a pre-set threshold, the system may send a warning to the surgeon indicating that the registration process should be re-started. Combination Cutting and Filing Blade Referring toFIGS.18-19an alternate cutting blade102′ is illustrated. The cutting blade102′ includes both an edge that can be used for cutting, as well as a surface that can be used for filing. Specifically, the cutting blade102′ has a cutting edge with a plurality of cutting teeth103. The teeth are formed in a row and may have a set. The row of teeth are operable to cut when the blade is reciprocated. The blade also includes a surface that can be used for filing, such as filing a bone surface during a procedure. As shown inFIGS.18-19, the blade has two sides, A and B. Side A is a generally smooth surface. Side B is on the side opposite from side A, and is formed with a plurality of cutting surfaces that form a filing surface. Specifically, side B is a generally elongated planar surface having a length and a width. A plurality of spaced apart ridges or teeth101protrude upwardly from the surface of the blade. Each ridge extends across the width of the blade so that the ends of each ridge terminate at the edges of the blade. However, the ridges101need not extend across the entire width of the blade. The ridges101on side B of the blade102′ form a secondary cutting surface that can be used for different procedures than the row of cutting teeth103. Specifically, the row of teeth103can be used to make a cut in a bone. In contrast, the ridges101form a filing surface that can be used to file a bone surface. Further, the cutting blade102′ can be used in a computer assisted technique, similar to those described above. The row of teeth can be used in a computer guided procedure in which the computer aligns the cutting blade to cut a portion of bone. Similarly, the filing teeth can be guided using a computer guided procedure in which the computer guides the filing teeth to remove a portion of bone that is identified for removal. Tool Registration Head One step during navigated surgery is the registration of the surgical tools. Registration is the process of identifying the specific location and orientation of a surgical tool. If a tool is not properly registered the navigation of the tool will be flawed leading to errors during the procedure. As discussed previously, the system may provide guidance by displaying a graphical illustration of the position of the surgical instrument relative to the patient. The system provides this guidance by tracking the location and orientation of the surgical instrument. For example, in the present instance, the surgical instrument100includes a frame having a plurality of markers105that are used to track the position and orientation of the surgical instrument. By tracking the location and orientation of the reference frame, the system can track the location and orientation of the surgical instrument. Since the structure of the surgical instrument is generally fixed relative to the reference frame, identifying the location and orientation of the reference frame can be used to identify the location and orientation of the surgical instrument. Although the configuration and dimensions of the surgical instrument are generally fixed, the surgical instrument may be used with one or more of a variety of different cutting tools or accessories during a procedure. For instance, the surgical instrument may use any of a number of different sized saw blades or drill bits. Since the tool is typically the part of the surgical instrument that actually operates on the patient tissue, it is important to accurately identify the configuration of the tool, as well as the location and orientation of the tool. To properly track the position of the tool during a procedure, the registration process identifies the configuration of the tool, as well as the location and orientation of the tool relative to the position detection element(s) on the surgical instrument. Specifically, the registration process identifies the position and orientation of the tool relative to the frame and markers105on the surgical instrument100. Referring toFIG.14, a tool registration head300is illustrated. The registration head300is designed to quickly and easily register a tool so that the system can accurately track the position and orientation of the tool. In this way, the registration head allows a surgeon to change tools during a procedure without the undue delay involved in known processes for registering a tool. In the following discussion, the registration head300is described in connection with registering a variety of cutting tools. However, it should be understood that this is an example of one type of tools that the registration head may be configured to register. The registration head can be configured to register any of a variety of cutting tools and/or accessories that can be used in the surgical instrument. The registration head300includes a plurality of sockets that are configured to mate with a plurality of cutting tools that can be used in the surgical instrument. The sockets are configured so that each socket cooperates with a particular tool. In this way, the system identifies the tool type in response to a determination of the socket into which the tool is mounted. In the present instance, the registration head300includes three rows of sockets. The first row312a,b,cis configured to register drill bits. The second row314a,b,cis configured to register saw blades; and the third row316a,bis configured to register other tools. The first row includes three sockets,312a,312band312c. Each socket is cylindrical having a different diameter. In this way, inserting a tool in the first socket312aregisters the tool as a drill bit having a particular diameter, inserting the tool in the second socket312bregisters the tool as a drill bit having a particular diameter, which in the present instance is larger than the diameter of the first socket. As can be seen, the registration block may have a series of numerous cylindrical sockets for registering numerous different drill bits. Each socket would have a different diameter for registering a particular diameter drill bit. The second row of sockets in the registration head300is configured to register saw blades, such as sagittal blades. Such blades are generally thin flat blades having a row of teeth on one end. The second row of sockets includes a first socket314ain the form of a rectangular slot having a height and width. The height corresponds to the thickness of a particular saw blade and the width corresponds to the width of the saw blade. Therefore, inserting a tool into the first saw blade socket314aregisters the tool as a sagittal blade having a predetermined width and thickness. Similarly, inserting a tool into the second saw blade socket314bregisters the tool as a sagittal blade having a predetermined width and thickness that is larger than the blade corresponding to the first saw blade socket314a. As with the sockets for the drill bits, it should be appreciated that the registration block can include a number of different sized slots configured to mate with numerous different saw blades. Each slot would be configured to mate with a specific saw blade so that the blade can be uniquely identified and registered by simply inserting the blade into the appropriate slot. In addition to the sockets, the registration head300also includes a plurality of position detection elements310. The position detection elements may be either passive marker elements or active marker elements, as discussed previously. The type of position detection elements is selected to cooperate with the tracking system120that is used. For instance, in the present instance, the registration head300includes a plurality of spaced apart spherical reflective markers310. The spacing and the orientation of the position detection elements310are known. Therefore, the tracking system120can determine the position and orientation of the registration head300by detecting the location of each position detection element310. Additionally, the position and/or configuration of the registration sockets in the head300is known. Accordingly, as described above, the tracking system120can track the position detection elements310on the registration head300to determine the position and orientation of the registration block. Similarly, the tracking system120can track the position detection elements105on the surgical instrument100to determine the position and orientation of the surgical instrument. Since each socket in the registration head defines a unique location for a particular tool, the position of the surgical instrument relative to the registration block is unique for each particular tool. The unique spacial relationships between the registration block and the surgical instrument is predetermined for each tool that the registration block is configured to register. Part of the information that is determined during the registration process is the position of the tip of the tool relative to the position detection elements105on the surgical instrument. As discussed above, the configuration and orientation of each tool relative to the surgical instrument can be determined depending upon the socket into which the tool is inserted. However, this process does not necessarily identify the position of the tip of the tool. For instance, if a tool is registered when the tool is inserted only halfway into a socket, the system will incorrectly assume that the tip of the tool is at a position corresponding to where the tip would be if the tool was fully inserted into the socket. To properly identify the location of the tip of a tool, each socket has a bottom wall that acts as a stop. The location of each bottom wall is a fixed location relative to the position detection elements310, which is pre-determined for the registration head. Since it is a fixed and known location, the bottom wall operates as the assumed location of the tip of the tool when a tool is inserted into a socket. Therefore, to properly register a tool, the tool is inserted into a socket until the tip of the tool engages the bottom wall of the socket. Based on the foregoing, a tool, such as a saw blade can be easily registered by simply attaching the tool to the surgical instrument100and then inserting the tool into the proper socket in the registration head310. The tool is fully inserted into the socket until the tip of the tool engages the bottom of the socket. During the registration process, the tracking system120tracks the position and orientation of the registration block relative to the surgical instrument, which identifies the configuration and orientation of the tool relative to the position tracking elements105on the surgical instrument. For instance, in the case of a saw blade, if the blade is inserted into slot314a, the relative position between the registration block and the surgical instrument identifies the tool as a saw blade having a particular height and width. Furthermore, the saw blade fits into the slot in a particular orientation, so the orientation of the blade is also know. In other words, the tracking system120tracks the position detection elements310to track the position and orientation of the registration head. The tracking system also tracks the position detection elements105on the surgical instrument to determine the position and orientation of the surgical instrument. As discussed previously, the spacial orientation between the surgical instrument and the registration block is pre-determined and unique for each socket. Therefore, when a tool is inserted into a socket in the registration head, the spacial orientation between the surgical instrument and the registration head300defines the boundaries of the tool relative to the tracking elements105on the surgical tool. Accordingly, after the tool is registered, the system can accurately track the boundaries of the tool mounted in the surgical instrument by tracking the position of the tracking elements105on the surgical instrument. The process for registering a tool may be either manual or automatic. In a manual mode, the tool is inserted into the proper socket until the tip of the tool contacts the bottom wall of the socket. While the tip is in contact with the bottom wall of the socket, the surgeon presses a button to indicate that the tool is properly registered in a socket. The system uses the positional data from the tracking system120at the time when the button was pressed to determine the position of the tracking elements310on the registration head300and the position of the tracking elements105on the surgical instrument100. Based on the position data, the system calculates the location of the boundaries of the tool relative to the tracking elements105on the surgical instrument. In addition to pressing the button, the indicator signal for registering a tool can be other various forms of inputs. For instance, the input signal could be a voice signal that is recognized be voice recognition software. Alternatively, the input signal could be an area on a touch screen, a click of a mouse, an input mechanism on the surgical instrument itself, a keyboard stroke or otherwise. In an automatic mode the surgeon need not press a button to indicate that the tool is inserted into the registration head300. Instead, the system automatically determines that the tool is inserted into a socket and makes the registration calculations. One automatic mode relies upon sensors in the registration head300. Specifically, a sensor is located in each socket of the registration head. The sensors may be any of a variety of types of sensors, such as an impedance sensor or a load transducer. The sensor detects whether a tool is in contact with the bottom wall of the socket. When the sensor detects that the tool is in contact with the bottom wall, the sensor sends a signal to the OR computer or the tracking system120. The signal from the sensor operates similar to the surgeon pressing the button in the manual mode described above. A second automatic mode may be used instead of the first automatic mode described above. The second automatic mode automatically registers the tool without using sensors in the registration head. In the second mode, the tool is inserted into the registration head300and is held in the appropriate socket for a pre-determined time period, such as 1 or 2 seconds. The system tracks the location of the surgical instrument relative to the registration block and registers the position of the tool when the surgical instrument is at a fixed position for the pre-determined time period. In this way, the period of time that the surgical instrument is stationary relative to the registration block operates as the trigger for registering the tool. Although the second automatic mode may use a hold time as the trigger, the system may need to ignore positions that do not correspond to valid registration positions. For instance, if the surgical instrument is stationary on a surface sitting next to the registration head, the tool will be stationary for a sufficient period to trigger registration. However, when the surgical instrument is sitting next to the registration head, the position of the surgical instrument relative to the registration block does not correspond to a valid registration position. Therefore, in the second automatic mode, the system may reject registration data corresponding to positions that are invalid registration positions. In another alternative mode, rather than rely on a hold time as the trigger, the system may simply evaluate the positional data to register a tool. Specifically, the system may monitor the position of the surgical instrument relative to the registration head to determine which of the sockets the tool is inserted into, as described above. As the tool is inserted into the socket, the surgical instrument will move in a particular direction. For instance, in the example of registering a drill bit, the surgical instrument will move towards the registration block along an axis as the drill bit is inserted into the corresponding socket. Assuming that the surgeon inserts the tool until it touches the bottom wall of the socket, the registration position will relate to the maximum point of travel along the axis. As with the second mode above, the system will ignore data that does not correspond to a valid orientation of having a tool inserted into one of the sockets. Once the tool is registered, the system tracks the boundaries of the tool by tracking the location of the tracking elements105on the surgical instrument. If the surgeon desires to use a different tool during a procedure, the surgeon simply needs to replace the tool with the new tool, indicate to the system that a new tool is to be registered, such as by pressing a button or otherwise, and then inserting the new tool into the appropriate socket in the registration block as described above. Since the registration process is quick and easy, the overall procedure is not significantly delayed when a new tool is needed. As discussed above, the positional data regarding the dimensional configuration of the registration block is pre-determined, as is data regarding the positional relationship between the surgical instrument and the registration block for each socket. This data is stored in either a file on the OR computer or the position detection system120. Similarly, data regarding each type of tool that correlates to each socket may be stored in a data file on the OR computer. Assessing and Correcting Bone Cuts When implanting a prosthetic onto a bone, the surgeon must resect portions of the bone to prepare the bone to receive the prosthetic. Regardless of how the resection is performed, it is helpful to assess the quality of the cuts performed during a procedure prior implanting the prosthetic. Bad fit between the bone and the prosthetic causes a significant number of implant failures. Therefore, a close match between the shape and dimensions of the prepared bone and the prosthetic is important to the proper affixation and durability of the implant. The surgeon may rely upon experience and trial and error during a procedure, however, doing so does not provide a quantifiable method for ensuring that a resection is proper. Accordingly, it may be desirable to incorporate a method and apparatus for assessing the quality of bone cuts before a prosthetic is implanted. Additionally, after assessing the bone cuts, it may be desirable to provide feedback regarding any additional shaping that should be made to improve the bone cuts to prepare the bone to receive the implant. The assessment of bone cuts evaluates four aspects: surface finish, fit, alignment and accuracy. The surface finish relates to the smoothness of the cut surfaces. The fit relates to how closely the bone shape matches the shape of the implant. The alignment relates to whether or not the cuts are made so that the implant is positioned in the proper three rotations of alignment, including the flexion/extension axis, the anterior/posterior axis, and the proximal/distal axis. The accuracy relates to the angle and orientation of each cut relative to the plane of the ideal cut. During a procedure, bone is resected according to the geometry of the prosthetic to be implanted. After the resection, the cut bone is analyzed to evaluate the four aspects mentioned above: surface finish, fit, alignment, and accuracy. Referring toFIG.1, the system for assessing the bone cut comprises a scanning device320that communicates with a processor, such as a personal computer, which may be the OR computer80. The processor communicates with an output device, such as a monitor85to illustrate information about the assessment of the bone cuts. The scanning device320may be one of a number of various devices for acquiring information. For instance, the scanning device320may be a probe such as the smart probe discussed above. The probe is traced over the cut surfaces to obtain data regarding each surface. Analysis of Surface Finish The processor analyzes the scanned data to evaluate each cut of the resected bone. For instance, as shown inFIG.10, in the case of a TKR procedure, there are typically five separate cuts made to the femur when the bone is resected to accommodate the prosthetic (it may be considered seven cuts rather than five when considering the posterior condyle resection as two cuts, as well as the posterior chamfer). The image data for the resected bone is analyzed to assess the surface finish for each of the five cuts. The analysis of surface finish may include an analysis of one or more characteristics to evaluate whether the surface is of sufficient quality to bond well with the prosthetic. In the present instance, the system analyzes the roughness and/or the waviness of the resected surface to assess the surface finish. Roughness includes the finer irregularities of a surface that generally result from a particular cutting tool and material conditions. Waviness includes the more widely spaced deviation of a surface from the nominal or ideal shape of the surface. Waviness is usually produced by instabilities, such as blade bending, or by deliberate actions during the cutting process. As illustrated inFIG.7, waviness has a longer wavelength than roughness, which is superimposed on the waviness. Based on analysis of the 3D geometrical image data, the surface finish for each cut is analyzed and quantified. In the present instance, the surface finish may be quantified based on: (1) the roughness average, (2) an average of the heights of a select number of the worst peaks (i.e. highest surface peak relative to ideal surface); (3) an average of the heights of a select number of the worst valleys (i.e. deepest valley relative to ideal surface); and (4) a measure of the deviation from the average height of the worst peaks and the average depth of the worst valley (i.e. (2)-(3)). In some instances, it may be desirable to separate the quantification of the measure of waviness from the measure of roughness. However, in the present instance, roughness and waviness are evaluated together. An example of a resected femur having unacceptable surface finish is illustrated inFIG.8. As can be seen, the geometry of the resection is proper, so that the prosthetic would fit properly onto the resected bone and be properly aligned. However, due to the poor surface finish it is likely that the bond between the bone and the prosthetic will fail prematurely. Based on the surface finish analysis, the surgeon may decide that one or more of the cuts may need to be smoothed, such as by filing. Analysis of Fit The second characteristic evaluated for the bone cuts is fit. Fit represents the looseness or play between the implant and the resected bone shape prior to affixing the prosthetic to the bone. An example of a resected femur having an unacceptable fit error is illustrated inFIG.8. As can be seen, the surface of each cut is acceptable and the orientation of each cut is acceptable, however, the resultant shape leaves unacceptable gaps between the prosthetic and the resected bone. The gaps create play or looseness that will lead to misalignment and/or premature failure of the bond between the bone and the prosthetic. To measure the fit error, a fitness measuring block340may be utilized. The fitness measuring block340is a block having an internal shape corresponding to the internal shape of the prosthetic (i.e. the surface that will bond with the bone). A tracking element345for detecting displacement is attached to the fitness measuring block. In the present instance, the tracking element is an infrared tracking device similar to the frame and markers105that are used to track the surgical instrument, as described above. Alternatively, a navigated implant trial that is specific to each prosthetic implant may be used rather than a measuring block. The navigated implant trial is an implant similar to the prosthetic that is to be implanted into the patient. The navigated implant would also include an element for detecting the position of the implant trial, such as the tracking element345described above. The tracking system20(seeFIG.1) tracks the position of the tracking element345and communicates data to the processor that is indicative of displacement of the measuring block340relative to the resected bone. To use the measuring block340, the block is placed over the resected bone. The surgeon then attempts to move the measuring block in all directions relative to the bone to evaluate translational error based on the amount of translation possible between the measuring block and the resected bone. Specifically, the surgeon rotates the block in flexion and extension, as well as internally and externally. In other words, the surgeon rotates the blocks about several axis relative to the bone, such as an axis running generally parallel to the axis of the bone (i.e. rotation internally and externally) as well as an axis running generally transverse the axis of the bone (i.e. rotation in flexion and extension). As the surgeon moves the measuring block, the tracking system120tracks the translational and rotational movement of the measuring block relative to the bone. The tracking system communicates the data regarding the movement of the measuring block with the OR computer80. Based on the data from the tracking system120, the OR computer analyzes and quantifies the fit based on the measured translational error and the measured rotational error. Specifically, the OR computer80analyzes the data regarding movement of the measuring block to measure extremes of movement of the measuring block relative to the bone. The extremes of movement are measured in each of six direction of movement/rotation. The extremes of motion indicate the looseness of the fit. If the measuring block can move significantly relative to the bone, then the extremes of movement will be significant. This will reflect a loose fit. Conversely, if the measuring block cannot move significantly relative to the bone, then the extremes will be relatively small. This will reflect a tight fit. Analysis of Alignment A third characteristic for assessing the cuts is the alignment of the cuts. The alignment assessment can be performed using the same data set that was collected while analyzing the implant fit as described above. The alignment error is a quantification of the deviation of the location of the measuring block from the ideal location at which the implants are to be positioned for proper alignment. Specifically, in the present instance, the alignment error is based on three rotational deviations and three translational deviations from the ideal locations. The deviations of the measuring block from the ideal position(s) are based upon the data obtained by the tracking system120during tracking of the measuring block to evaluate the fit, described above. The OR computer80analyzes the data regarding the movement of the measuring block relative to the resected bone. The OR computer80analyzes the data to evaluate whether the measuring block passed through the ideal alignment position as the block was moved between the extremes of movement. If the measuring block passes through the ideal alignment during the test manipulation, the alignment is correct; if not, the alignment is off. To evaluate the alignment error, the computer analyzes the data from the tracking system to determine how close the measuring block came to the proper alignment position. This deviation is analyzed for the six parameters about the three rotational axes mentioned above. In other words, for each axis of rotation, the system determines the position that the measuring block should pass through to be ideally aligned in the axis of rotation. The system determines how close the measuring block came to the ideal position when the block was rotated along the same axis of rotation. The deviation is analyzed for each axis to obtain an overall error measurement. Analysis of Accuracy A fourth characteristic used in the present instance to evaluate the bone cuts is the accuracy of each cut. For example, in the instance of a TKR procedure, the accuracy of each cut is evaluated. The importance of the accuracy of the cuts is exemplified by the third sample illustrated inFIG.8. As can be seen, the sample has acceptable surface finish, fit and location. In other words, the prosthetic will fit well on the bone (i.e. it won't wiggle excessively), the surface finish is not too rough or wavy and the prosthetic will be properly aligned with the bone. However, due to the inaccuracy in one or more of the cuts, there will be gaps between the prosthetic and the bone that will increase the likelihood of premature failure. To evaluate the accuracy of the cuts, the deviation between the actual cuts and the ideal cuts for the particular prosthetic is measured. The ideal cuts are determined based on the geometry of the prosthetic to be implanted on the resected bone. For instance, in the example of a TKR, the ideal cuts for the femur are based on the internal configuration of the femoral prosthetic. One way of determining the ideal cuts is to create a model of the configuration of the ideal cuts for the patient. In the present instance, a scanner can be used to create a three dimensional model of the resected bone, as discussed further below. The data obtained from the scanner for each planar resected surface is compared with the data for the corresponding surface of the ideal resected model to evaluate the accuracy of the cuts. The quantification of the accuracy can be based on a variety of measurements regarding the deviation of each resected surface from the ideal surface. To assess accuracy, the plane of each cut is calculated using a best fit plane. The deviation of the best fit plane from the ideal plane is analyzed to determine accuracy. Specifically, in the present instance, four characteristics are measured to assess accuracy. The first characteristic is a translational measurement, and it is calculated as the distance between the best fit plane of the resected surface and the centroid of the corresponding ideal cut. The remaining three characteristics are rotational angles. The first rotational characteristic is the orientation of the resected surface relative to the ideal plane with respect to a first axis; the second rotational characteristic is relative to a second axis and the third rotational characteristic is relative to a third rotational axis. These characteristics are measured and correlated to quantify the accuracy of each planar cut of the resected bone. Each cut is analyzed independently in the accuracy assessment. Therefore, the assessment can be used to detect which adjustments need to be made to a cut if the cut exceeds an error threshold. The system can suggest one or more cuts or modifications to be made based on an analysis of the resected bone and the ideal cuts. In the foregoing description, the evaluation of the location error and fit error are based on measurements provided by manipulating the fit measurement block340relative to the resected bone. Alternatively, the fit and location errors may be evaluated using a virtual comparison of the resected bone and models of ideal location and fit for the bone. For instance, the resected bone may be scanned to create a three dimensional model of the resected bone. The scanner may use electromagnetic, ultrasonic/acoustic, mechanical, infra-red line-of site, or other elements. For instance, a three dimensional optical laser scanner, scriber, navigated digitizer, coordinate measuring machine or CT-based digitization can be used to create a digital model of the bone surface. Prior to the procedure a three dimensional model of the relevant portion of the patient can be created using any of a variety of techniques, including but not limited to CT scans and MRI images. The processor may include a database of models corresponding to various prosthetics. The surgeon selects the appropriate prosthetic model and positions it relative to the model of the relevant portion of the patient. The processor then modifies the patient model to reflect the ideal resected surfaces for the selected prosthetic. Using collision detection algorithms, the scanned data for the resected bone can be compared with the data for the model for the ideal resected bone to calculate the various criteria used to measure fit error, alignment error and/or accuracy error. Feedback from Assessment After the processor determines the various criteria to assess the quality of the cuts, the information regarding the criteria may be displayed on the monitor to indicate to the surgeon whether or not the cuts were of sufficient quality to proceed with implanting the prosthetic on the bone. Additionally, if the cuts are not of sufficient quality, the processor may evaluate the cuts to determine a strategy for modifying the resected bone to improve the quality of the cuts. For instance, based on a comparison of the scanned data for a resected bone with the data for the model of an ideal resected bone, the processor may determine the portion(s) of bone that should be re-shaped to improve the correlation between the resected bone and the model for the ideal resected bone. After determining the portions of the bone that should be re-shaped, such changes are displayed on the monitor to show the surgeon which portion(s) of the bone should be removed. For example, using a graphical output, the bone may be illustrated generally in white and the portion(s) of the bone that should be resected to improve the fit with the prosthetic may be shown in red. Intraoperative Surgical Motion Recording As discussed previously, during a procedure, the tracking system120tracks the position and orientation of the surgical instrument100. This tracking data is used to provide real-time feedback and/or guidance during the procedure. In addition, the system may store the tracking data for later review and/or analysis. For instance, after a procedure, a surgeon can review the stored data to see each step that was taken during a procedure and the order in which each step was taken. Such analysis can provide valuable insight into advantages and/or disadvantages of particular steps of particular procedures. The tracking system120is designed to track the movement of the tracking elements105of the surgical instrument. The tracking system is able to track the tilt, roll, pitch and offset of the surgical instrument as it in manipulated. Further, the tracking system120is able to track the position, and orientation of the surgical instrument and the speed of movement. Further still, the system is able to track the position of the surgical instrument relative to the bone. The tracking data is stored, so that it can be re-called to review a procedure. Specifically, the data can be re-called so that each step of a procedure can be reviewed in the sequence that each step was performed during the procedure. As discussed previously, the tracking system120tracks the position and orientation of the surgical instrument100and the system correlates the position of the instrument with the position of the patient. The system then displays an illustration of the position of the surgical instrument relative to the patient. Specifically, the system displays a model of the patient tissue and displays a model of the surgical instrument in a position and orientation relative to the model corresponding to the tracked position and orientation of the instrument relative to the patient. Since the stored data relates to the three-dimensional position and orientation of the surgical instrument relative to the patient, the data can be used to display a three-dimensional representation of the surgical procedure. For instance, similar to the playback of a movie, the stored data can be used to display an illustration of each step in a procedure in the sequence that each step occurred. Additionally, since the tracking data includes three-dimensional information, the illustration is not limited to the view that was displayed during the procedure, as would be the case if a movie was taken of the procedure and then watched later. In contrast, during the review of the procedure, the tracking data can be used to watch a step of the procedure from any desired perspective or view. For example, during a procedure, a certain cut may be guided by viewing the patient model from an anterior view. When reviewing the data stored for the procedure, the user may view the step from a posterior view, or any other view that the user desires. In this way, the user may evaluate each step from any number of perspectives to identify how a step was accomplished and/or the result of a particular step. The stored tracking data can be used in a variety of applications. For instance, a surgeon may review the tracking data to assess the efficiency or effectiveness of various procedures. Similarly, the data can be used to teach procedures to other surgeons, such as less experienced surgeons. The less experienced surgeon will be able to see exactly what steps were taken and the result of each step and the result of the overall procedure. In addition, to allowing the review of data from a procedure, the tracking system can be used to simulate a procedure. Using the patient model, the surgeon may manipulate the surgical instrument to simulate the steps taken during a procedure. The system tracks the manipulation of the surgical instrument and illustrates the effect of each manipulation on the patient model. The surgeon can see the effect of each manipulation on the patient model in real-time. In this way, the simulation allows a surgeon to test or evaluate a procedure on a model of the patient. The data regarding the simulation can be recalled during an actual procedure to guide the surgeon. In the alternative, the stored data can be used to guide a automated surgical instrument, such as a surgical robot. The surgeon can manipulate a surgical instrument to perform a simulated procedure, as discussed above. Once the surgeon has finalized and validated each step in a procedure, the data regarding the position and orientation of the surgical instrument at each step of a procedure is stored. The stored data is then used to guide an automated surgical instrument, such as a robot, to perform the procedure. The automated instrument will follow the guidance of the stored data, so that the surgical instrument is manipulated to track the actions of the surgical instrument during the simulated procedure. Anchoring Device for Surgical Tool When performing a navigated freehand, one of the issues is maintaining the alignment of the surgical instrument, particularly during the start of a cut. For instance, at the beginning of a cut the saw blade may tend to wander from the desired cut line or plane. However, once the cut begins, the blade creates a kerf, which tends to limit the movement of the saw blade. Unfortunately, if the saw moves out of alignment at the beginning of a cut, the saw kerf can constrain the saw blade in a plane that is out of alignment, thereby furthering the problem created when the saw moved at the start of the cut. To limit the misalignment that may occur at the beginning of a cut, the surgical tool may includes an anchoring device mounted on the surgical tool. Referring toFIG.4, the anchoring device115is an elongated element positioned adjacent the cutting tool102. The forward end of the anchoring device115is positioned so that the tip of the anchoring device protrudes beyond the tip of the cutting tool. In the present instance, the anchoring device115includes a plurality of pins or spikes116positioned at the end of the anchor. The pins116are configured to anchor the anchor115into bone, and the pins may retract after a cut begins. The anchoring device115may also include a recess for receiving the pins116when the pins retract so that the pins do not interfere with the cutting operation of the tool. Although the anchoring device115can be configured in a variety of shapes, in the present instance, the anchoring device is an elongated flat bar positioned parallel to the cutting blade102and in close proximity to the cutting blade. The anchor115preferably is more rigid than the cutting blade, and preferably is substantially rigid relative to the cutting blade. In this way, the anchoring device supports the cutting tool, limiting the deflection of the cutting blade toward the anchor. During a procedure, the anchoring device operates as follows. As described above, the surgeon views the monitor to properly align the surgical tool to perform the cut. After the surgical instrument is aligned, the surgical instrument is anchored to the bone by driving the instrument toward the patient bone to anchor the pins116in the bone. The surgical instrument may include an internal hammering device to lock the anchoring pins116to the bone when the alignment is correct, or the surgical instrument can include a portion, such as an anvil118, that can be hammered to drive the pins116into the bone. Once the anchoring device115is driven onto the bone, the anchoring device constrains the movement of the surgical instrument. Specifically, the anchoring device115limits lateral movement of the surgical instrument relative to the bone. However, the anchoring device allows the rotational of the surgical instrument relative to the bone, and preferably, at least some axial displacement of the surgical instrument toward the bone. In this way, the anchoring device allows the cutting blade to be aligned and maintained with the proper location to begin a cut. At the same time, the anchoring device115allows the surgical instrument to rotate so that the cutting blade can be aligned with the plane of the proper cut and advanced into the bone. As described below, during a cut, the anchor115may be configured to collapse. Accordingly, to anchor the pins into the bone, the anchor115includes a brake or a lock to lock the anchor in an extended position while the pins are anchored into the bone. Once the anchor115is anchored to the bone, the surgeon starts the tool and the cutting blade102is driven into the bone. The lock or brake on the anchor is released to allow the anchor to collapse during a cut. Specifically, the anchor115is configured so that it can collapse or telescope as the saw is moved forward during the procedure. In other words, the pins116remain in engagement with the tissue (e.g. bone) and the anchor115collapses as the saw move forward relative to the pins. In this way, the pins116anchor the cutting blade102as the cutting blade progresses through a cut. As described above, the anchoring device includes a flat bar and retractable pins. However, the configuration of the anchor can vary based on a number of criteria, including, but not limited to design, friction and heat requirements, sterilization needs etc. For instance, rather than being an elongated flat bar, the anchor may comprise a pair of elongated cylindrical rods spaced apart from one another. The ends of the rods may be pointed to facilitate anchoring the anchor into the bone, as shown inFIG.5. Additionally, the anchoring device need not include retractable elements. Instead, the anchoring device may be a rigid element that is removable from the surgical instrument. In use, the anchoring device is driven into the bone to anchor the surgical instrument relative to the bone. The surgical instrument is then operated to start a cut. After the cut is started, the surgical tool is withdrawn and the anchoring element is removed from the surgical tool. The saw kerf that was started is then used to guide the rest of the cut. Tool Bending & Deflection Correction As described above, the tracking system120can be used to detect and monitor the position of either a surgical tool100or a surgical robot200. One issue in correctly navigating the surgical tool or the robot is the need for an accurate assessment of the position and orientation of the surgical tool or robot. Specifically, although a number of markers105may be used to identify the position of a tool, markers are typically not applied to the tip of a tool, particularly if the tool is a cutting tool. Instead, the position of the tool is determined and the position of the cutting tip is calculated based on the known geometry of the tool, and the presumption that the tool is a rigid element. However, during use, the tool may deflect or deform so that the actual position of the cutting tip may not correspond to the presumed position of the cutting tip. Therefore, the correlation between the actual tissue being cut and the virtual model do not match. In other words, based on the data received from the position detection device the OR computer80may determine that a certain portion of tissue is resected, however, due to tool deflection the actual tissue resected may be different. The system may compensate for the tool bending or deflection in one of several ways. Using system compensation, the system can monitor and calculate the tool bending, and then manipulate the tracking data to compensate for the calculated bending. Alternatively, using on-board compensation, the compensation calculations are determined and affected on-board the surgical instrument. Using system compensation, the tool may include a sensor for detecting deflection or deformation of the tool. For instance, referring toFIG.2, a surgical tool100is illustrated, having a cutting blade102. The surgical tool100reciprocates the cutting blade during operation. A sensor in the form of a load-cell104included in the saw detects the force and/or torque applied to the blade. Alternatively, a piezoelectric sensor may be connected directly to the blade to detect the force and/or torque applied to the blade. The measured force or torque is used to predict the distance “d” that the blade bends. Specifically, properties of the cutting blade102are stored. Based on the predefined cutting tool properties and the measured force or torque, the amount of bending is calculated. The calculated amount of bending approximates the distance “d” and is used as a compensation factor to adjust the position and orientation of the cutting tool detected by the position detection device120. Specifically, not only will the system process the tracking data to compensate for the position of the cutting tool, the system will also process the tracking data to compensate for the angle of the deflected cutting tool. The advantage of using system compensation is that the alterations to the surgical instrument are minimized. However, system compensation requires that the system be programmed to alter the processing of the tracking data, as discussed above. While this may not be a barrier for a new system, users that already have a system with a tracking system may be hesitant to adopt a process that requires alteration of the tracking software or the software that processes the tracking data. Accordingly, it may be desirable to make the bending compensation adjustment on board the surgical instrument. The modified surgical instrument can then be used with the user's existing tracking system without any further modifications. In the on-board approach, the surgical instrument includes an onboard processor that calculates the tool deflection. Based on the calculated deflection, the surgical instrument manipulates the tracking element(s) to compensate for the deflection. In this way, the position detection device120will detect the compensated position of the cutting tool, which will reflect the actual position and orientation of the deflected cutting tool. Referring again toFIG.2, the surgical tool100may include a processor106operable to receive signals from the load cell104indicative of the force applied to the cutting blade. Based on the data received from the load cell, the processor106calculates the deflection “d” of the tip of the cutting tool102and the angle at which the blade is deflected. The system, then manipulates the tracking element on the surgical instrument. In the present instance, the surgical tool includes a reference frame onto which a plurality of markers105are mounted. As described previously, the tracking system120detects the position of the markers to determine the location and orientation of the surgical tool. In a system compensation design, the frame is typically rigidly mounted to the surgical tool so that the position of the markers relative to the rest of the tool is fixed. However, as shown inFIG.2, the frame107may be movably connected to the surgical tool100. Although the freedom of movement of the frame may be limited, preferably the frame is connected to the surgical frame by a connection that provides at least two degrees of freedom, such as a universal joint. Furthermore, in the present instance, the frame is extendable and retractable to alter the length of the frame to properly compensate for the position and orientation of the deflected blade. Connected to the frame107are a plurality of actuators or deflectors108that control the position of the frame. The actuators108are in electrical communication with the processor106, and preferably the processor106independently controls the operation of each actuator. The processor106controls the operation of the various deflectors108based on the signals received from the sensor104. Specifically, as described above, the processor106calculates the deflection “d” of the tip of the cutting tool based on the signal received from the sensor104. Based on the calculated deflection, the processor determines the appropriate compensation to the position of the frame to compensate for the deflection of the cutting tool102. The processor then controls the operation of the actuators108to re-position the frame. For instance, in the example illustrated inFIG.2, the cutting tool is deflected an amount “d” in a clockwise direction. Accordingly, the actuators108reposition the frame107to displace the markers105an amount “d” in a clockwise direction. Additionally, the vertical actuator is operated to alter the height of the frame107to compensate for the proper plane of the deflected tool. The position detection device120then detects the position of the surgical tool at the compensated position so that no further calculations are necessary to monitor the position of the deflected cutting tool. By utilizing an on board deflection compensation, the system can incorporate deflection compensation, while still allowing the surgical tool to be used with a variety of commercially available position detection devices without the need to modify the software used by such devices. Although the foregoing example describes the onboard compensation feature as utilizing a plurality of actuators to reposition a reference frame, the configuration of the compensation elements may vary depending on the configuration of the position detection elements used. For instance, other position detection devices may be used in the system, such as systems that include electromagnetic sensors, ultrasound elements or accelerometers. When such elements are utilized, the compensation features may either vary the position of the element or it may vary the data provided by such elements in response to the data received regarding the load on the cutting tool. Intelligent Control of Surgical Instrument As described previously, the present system50can be used to perform guided freehand surgery in which a model of the patient is provided, along with a model of the surgical tool and the models can be used to guide the surgeon during the actual procedure. For instance, the patient model may include a portion identified as tissue to be resected. The system tracks the movement of the surgical tool100, so that when the surgeon moves the tool, the system displays the movement of the tool in real time on the monitor. In this way, the surgeon can align the tool with the patient by aligning the model of the tool with the portion of the patient model identified for resection. In this way, the surgeon can follow the onscreen guidance to resect a portion of tissue. During the procedure, the system may control or modulate the surgical instrument in response to the position of the surgical instrument. Specifically, as discussed previously, the system may track the position and orientation of the surgical instrument relative to the patient. If the surgical instrument is not in the proper position or orientation relative to the patient, the system may control the surgical instrument, such as by stopping the instrument to ensure that the surgical instrument does not operate on the wrong portion of tissue. Further still, in an alternate design, the system can intelligently control the operation of the surgical instrument based on additional data, such as the degree of mis-alignment or the location of the incorrectly positioned instrument. For example, if the surgical instrument is in a position that does not correspond to the desired cut, it may not be a location that warrants automatically shutting off the instrument. For instance, the surgeon may be holding the surgical instrument so that the saw blade is away from the patient and in mid-air. In such a position, the instrument is not in the correct position to make a cut, but the instrument will not to any harm in the air. Therefore, there is no need for the system to control the operation of the instrument. Conversely, if the instrument is positioned adjacent the patient's tissue and it is improperly located and/or oriented. It may be desirable to control the operation of the instrument to prevent the surgeon from cutting tissue erroneously. Accordingly, the system may control the operation of the surgical instrument in response to the location and orientation of the surgical instrument relative to the patient, combined with data about the area around the surgical instrument and whether the area around the surgical instrument can be damaged. In addition, in some instances, the surgical instrument may not be properly oriented or positioned, however the misalignment/misorienatation may be minor. A minor error may not warrant the degree of automated override that a significant misalignment warrants. Accordingly, the operation of the surgical instrument may be controlled in response to the degree of deviation from the desired position or orientation of the surgical instrument. Specifically, the degree of control may correlate to the degree of error. The greater the error, the greater the control. For example, a minor error in alignment may cause the system to attenuate the rate of the saw by a minor amount, whereas a substantial misalignment of the saw in a critical area of tissue may cause the system to stop the saw. When controlling the operation of the surgical instrument, the control can either affect the range of modulation or the control can actually modulate the surgical instrument. For example, if the surgical instrument is improperly positioned, the saw may be controlled so that it can only be operated by 0-50% normal speed. In other words, the instrument can be operated in an attenuated range. Alternatively, the instrument could be controlled so that the instrument operates at an attenuated speed, such as 50%. The control or attenuation of the surgical instrument may be based on control signals received from the OR computer based on pre-defined data for the procedure and data from the tracking system. Alternatively, the surgical instrument may include an onboard processor that determines the proper control based on the tracking data and pre-defined data for the procedure. Optional Features for the Surgical Instrument As discussed previously, the surgical instrument100includes a cutting tool102and a tracking element, such as a frame107with passive markers105, as shown inFIGS.1&2. However, the surgical instrument may include a variety of optional features. For instance, referring toFIG.3an alternate embodiment of surgical instrument500is illustrated along with corresponding elements for a system. The surgical instrument500is operable to assist in automated surgery in a surgical suite as discussed above in connection with the surgical instrument100described above. For instance, as described above, the system may include a tracking system120that operates to detect the position of the surgical instrument500relative to the patient. In the present instance, the position detection device detects the position of one or more markers505on the surgical instrument and one or more markers connected to the patient. Although the instrument illustrates the markers on a frame as with the first embodiment, the markers need not be mounted on a frame. Instead, as shown inFIG.20, the markers605may be embedded in the structure of the surgical instrument600, such as on the housing610away from the gripping area602, or on the barrel or top portion of the surgical instrument. If embedded markers are utilized, the markers605include a portion that is readily visible to either transmit a signal or light if they are active markers, or reflect light or other signal if the markers are passive markers. In the present instance, the markers605are passive markers that are embedded in the surgical instrument. The markers are located on multiple positions of the instrument and on multiple faces, so that the tracking system can identify the orientation of the instrument regardless of which face of the instrument is facing the tracking system. In addition to other aspects, the surgical instrument500incorporates a number of features on board the instrument itself so that the instrument can be used to perform a number of functions independent of the processing done by the OR computer80. Additionally, the surgical instrument may incorporate wireless communication with the OR computer80. Referring toFIG.3the surgical instrument500includes a tool, such as a saw510, a microcontroller515for monitoring and controlling operation of the tool510, and a wireless unit520. The instrument500also includes an antenna525. The wireless unit520and antenna525allow the instrument to send data to the OR computer80regarding multiple status parameters, such as blade bending, saw speed and battery charge. In addition, the OR computer80includes a wireless unit86, such as a bluetooth wireless element, and an antenna87. The wireless unit86and antenna87allow the OR computer to send and receive data wirelessly to and from the surgical instrument500. As described previously, the OR computer80may be used to guide the surgeon's operation of the surgical tool during a procedure. For instance, the system may track the position of the surgical tool in real time and turn on or off the surgical tool depending on whether the tool is in proper alignment. For instance, if the system detects that the surgical tool is adjacent an area to be resected, the system may send a signal wirelessly to the tool. If the tool does not receive such a signal, the tool will not operate. Specifically, the surgical tool may have a manual switch that the surgeon can manually turn on to operate the tool. However, the tool will only run if both the manual switch is switched to the on position and if the tool also receives a signal indicating that the tool is properly positioned to perform a procedure. If either the surgeon switches the tool off or if the tool does not receive a signal indicating that the tool is properly positioned, the tool will not turn on for cutting. As described above, the tool500may receive signals wirelessly to control operation of the tool. In addition to signals controlling the on/off function of the tool, signals may also be used to control other operation of the tool. For instance, the tool may receive signals that operate to control the speed of the tool. For example, as described above, the system may track the position of the tool, so that the system can track whether the tool is adjacent a cutting boundary for a desired procedure. As the tool approaches the boundary, the system may send a signal to the tool indicating that the tool should be attenuated to reduce the speed of the tool. The circuitry in the tool500then attenuates the operation of the tool in response to the wireless signal. In addition to the system controlling the surgical instrument via wireless signals, the surgical instrument may control operation of the system via wireless signals For instance, the surgical tool may include various actuators, such as buttons, a joystick or a mouse ball. The operation of such actuators may be used as input signals to control operation of the OR computer. For example, operation of a joystick on the surgical tool500may send signals to the OR computer80, causing the graphics displayed on the display85to scroll in a particular direction. Similarly, one or more buttons can be programmed to send wireless signals to change the perspective or magnification of the graphic being displayed. In addition to including actuators, the surgical tool500may include a display530or view screen as shown inFIG.16. Specifically, as described above, the tool may include a wireless connection for receiving data from the OR computer80. The OR computer may transmit graphics data to the tool so that the display530may display the same graphics as are displayed on the main OR computer80display85. Alternatively, the display530may display an alternate view to the graphic being displayed on the OR computer display85. For instance, the small screen may show just a portion of the image shown on the large display85. The small area may be automatically determined based on the area of interest in the view on the main display. Alternatively, the system may incorporate a number of pre-defined or user defined views, similar to the pre-defined views discussed above. The pre-defined views may be an entire list of views that are defined for the small screen. Additionally, as with the main display, the surgical instrument may be configured to automatically change the view based on the position and orientation of the surgical instrument, or in response to the view being shown on the main display85. Further still, as shown inFIG.20, the onboard screen630may be positioned so that it is in-line with the cutting instrument, and the small display may include one or more alignment elements on the view. For instance, the view on the onboard display that includes alignment lines or indicators that show angular alignment, such as roll, pitch etc. Still further, the onboard display may include lines such as a line showing where the surgical instrument should be located along with a line showing where the surgical instrument is actually located. Further still, the onboard screen may be a touch screen to allow input controls directly through the onboard screen. In this way, the display screen530may be used to guide the surgeon during a procedure in the same way that the OR computer display85may be used to guide the surgeon. As previously discussed, preferably a pointer is provided for identifying reference points on the patient. Although the pointer has been described as a separate element, the pointer may be integrated into the surgical tool. For instance, since the configuration of the saw blade is known, the tip of the saw blade can operate as a pointer. Alternatively, a dedicated pointer may be incorporated onto the surgical tool. It may be desirable to configure the pointer so that it can be extended and retracted as necessary so that the pointer can be readily used, while not interfering with the operation of the cutting tool during a procedure. The operation of the pointer element may operate in conjunction with an actuator on the surgical tool. For instance, the tool may include a button for indicating that the pointer is positioned at a reference point. When the surgeon positions the pointing element at a point to be registered, the surgeon simultaneously presses the button, sending a signal to the OR computer indicating that the point is to be registered as a reference point. The OR computer detects the position of the surgical tool as determined by the position detection device, and stores the data regarding the location of the reference point. In this way, the OR computer stores information regarding the position of the surgical tool in response to actuation of the button on the surgical tool. It will be recognized by those skilled in the art that changes or modifications may be made to the above-described embodiments without departing from the broad inventive concepts of the invention. It should therefore be understood that this invention is not limited to the particular embodiments described herein, but is intended to include all changes and modifications that are within the scope and spirit of the invention as set forth in the claims.

11857266

DETAILED DESCRIPTION OF THE INVENTION It is to be understood that the present disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the description herein or illustrated in the drawings. The teachings of the present disclosure may be used and practiced in other embodiments and practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. The following discussion is presented to enable a person skilled in the art to make and use embodiments of the present disclosure. Various modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the principles herein can be applied to other embodiments and applications without departing from embodiments of the present disclosure. Thus, the embodiments are not intended to be limited to embodiments shown, but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the embodiments. Skilled artisans will recognize the examples provided herein have many useful alternatives and fall within the scope of the embodiments. Turning now to the drawing,FIGS.1and2illustrate a surgical robot system100in accordance with an exemplary embodiment. Surgical robot system100may include, for example, a surgical robot102, one or more robot arms104, a base106, a display110, an end effector112, for example, including a guide tube114, and one or more tracking markers118. The surgical robot system100may include a patient tracking device116also including one or more tracking markers118, which is adapted to be secured directly to the patient210(e.g., to the bone of the patient210). The surgical robot system100may also utilize a camera200, for example, positioned on a camera stand202. The camera stand202can have any suitable configuration to move, orient, and support the camera200in a desired position. The camera200may include any suitable camera or cameras, such as one or more infrared cameras (e.g., bifocal or stereophotogrammetric cameras), able to identify, for example, active and passive tracking markers118in a given measurement volume viewable from the perspective of the camera200. The camera200may scan the given measurement volume and detect the light that comes from the markers118in order to identify and determine the position of the markers118in three dimensions. For example, active markers118may include infrared-emitting markers that are activated by an electrical signal (e.g., infrared light emitting diodes (LEDs)), and passive markers118may include retro-reflective markers that reflect infrared light (e.g., they reflect incoming IR radiation into the direction of the incoming light), for example, emitted by illuminators on the camera200or other suitable device. FIGS.1and2illustrate a potential configuration for the placement of the surgical robot system100in an operating room environment. For example, the robot102may be positioned near or next to patient210. Although depicted near the head of the patient210, it will be appreciated that the robot102can be positioned at any suitable location near the patient210depending on the area of the patient210undergoing the operation. The camera200may be separated from the robot system100and positioned at the foot of patient210. This location allows the camera200to have a direct visual line of sight to the surgical field208. Again, it is contemplated that the camera200may be located at any suitable position having line of sight to the surgical field208. In the configuration shown, the surgeon120may be positioned across from the robot102, but is still able to manipulate the end effector112and the display110. A surgical assistant126may be positioned across from the surgeon120again with access to both the end effector112and the display110. If desired, the locations of the surgeon120and the assistant126may be reversed. The traditional areas for the anesthesiologist122and the nurse or scrub tech124remain unimpeded by the locations of the robot102and camera200. With respect to the other components of the robot102, the display110can be attached to the surgical robot102and in other exemplary embodiments, display110can be detached from surgical robot102, either within a surgical room with the surgical robot102, or in a remote location. End effector112may be coupled to the robot arm104and controlled by at least one motor. In exemplary embodiments, end effector112can comprise a guide tube114, which is able to receive and orient a surgical instrument608(described further herein) used to perform surgery on the patient210. As used herein, the term “end effector” is used interchangeably with the terms “end-effectuator” and “effectuator element.” Although generally shown with a guide tube114, it will be appreciated that the end effector112may be replaced with any suitable instrumentation suitable for use in surgery. In some embodiments, end effector112can comprise any known structure for effecting the movement of the surgical instrument608in a desired manner. The surgical robot102is able to control the translation and orientation of the end effector112. The robot102is able to move end effector112along x-, y-, and z-axes, for example. The end effector112can be configured for selective rotation about one or more of the x-, y-, and z-axis, and a Z Frame axis (such that one or more of the Euler Angles (e.g., roll, pitch, and/or yaw) associated with end effector112can be selectively controlled). In some exemplary embodiments, selective control of the translation and orientation of end effector112can permit performance of medical procedures with significantly improved accuracy compared to conventional robots that utilize, for example, a six degree of freedom robot arm comprising only rotational axes. For example, the surgical robot system100may be used to operate on patient210, and robot arm104can be positioned above the body of patient210, with end effector112selectively angled relative to the z-axis toward the body of patient210. In some exemplary embodiments, the position of the surgical instrument608can be dynamically updated so that surgical robot102can be aware of the location of the surgical instrument608at all times during the procedure. Consequently, in some exemplary embodiments, surgical robot102can move the surgical instrument608to the desired position quickly without any further assistance from a physician (unless the physician so desires). In some further embodiments, surgical robot102can be configured to correct the path of the surgical instrument608if the surgical instrument608strays from the selected, preplanned trajectory. In some exemplary embodiments, surgical robot102can be configured to permit stoppage, modification, and/or manual control of the movement of end effector112and/or the surgical instrument608. Thus, in use, in exemplary embodiments, a physician or other user can operate the system100, and has the option to stop, modify, or manually control the autonomous movement of end effector112and/or the surgical instrument608. Further details of surgical robot system100including the control and movement of a surgical instrument608by surgical robot102can be found in co-pending U.S. patent application Ser. No. 13/924,505, which is incorporated herein by reference in its entirety. The robotic surgical system100can comprise one or more tracking markers118configured to track the movement of robot arm104, end effector112, patient210, and/or the surgical instrument608in three dimensions. In exemplary embodiments, a plurality of tracking markers118can be mounted (or otherwise secured) thereon to an outer surface of the robot102, such as, for example and without limitation, on base106of robot102, on robot arm104, or on the end effector112. In exemplary embodiments, at least one tracking marker118of the plurality of tracking markers118can be mounted or otherwise secured to the end effector112. One or more tracking markers118can further be mounted (or otherwise secured) to the patient210. In exemplary embodiments, the plurality of tracking markers118can be positioned on the patient210spaced apart from the surgical field208to reduce the likelihood of being obscured by the surgeon, surgical tools, or other parts of the robot102. Further, one or more tracking markers118can be further mounted (or otherwise secured) to the surgical tools608(e.g., a screw driver, dilator, implant inserter, or the like). Thus, the tracking markers118enable each of the marked objects (e.g., the end effector112, the patient210, and the surgical tools608) to be tracked by the robot102. In exemplary embodiments, system100can use tracking information collected from each of the marked objects to calculate the orientation and location, for example, of the end effector112, the surgical instrument608(e.g., positioned in the tube114of the end effector112), and the relative position of the patient210. In exemplary embodiments, one or more of markers118may be optical markers. In some embodiments, the positioning of one or more tracking markers118on end effector112can maximize the accuracy of the positional measurements by serving to check or verify the position of end effector112. Further details of surgical robot system100including the control, movement and tracking of surgical robot102and of a surgical instrument608can be found in co-pending U.S. patent application Ser. No. 13/924,505, which is incorporated herein by reference in its entirety. Exemplary embodiments include one or more markers118coupled to the surgical instrument608. In exemplary embodiments, these markers118, for example, coupled to the patient210and surgical instruments608, as well as markers118coupled to the end effector112of the robot102can comprise conventional infrared light-emitting diodes (LEDs) or an Optotrak® diode capable of being tracked using a commercially available infrared optical tracking system such as Optotrak®. Optotrak® is a registered trademark of Northern Digital Inc., Waterloo, Ontario, Canada. In other embodiments, markers118can comprise conventional reflective spheres capable of being tracked using a commercially available optical tracking system such as Polaris Spectra. Polaris Spectra is also a registered trademark of Northern Digital, Inc. In an exemplary embodiment, the markers118coupled to the end effector112are active markers which comprise infrared light-emitting diodes which may be turned on and off, and the markers118coupled to the patient210and the surgical instruments608comprise passive reflective spheres. In exemplary embodiments, light emitted from and/or reflected by markers118can be detected by camera200and can be used to monitor the location and movement of the marked objects. In alternative embodiments, markers118can comprise a radio-frequency and/or electromagnetic reflector or transceiver and the camera200can include or be replaced by a radio-frequency and/or electromagnetic transceiver. Similar to surgical robot system100,FIG.3illustrates a surgical robot system300and camera stand302, in a docked configuration, consistent with an exemplary embodiment of the present disclosure. Surgical robot system300may comprise a robot301including a display304, upper arm306, lower arm308, end effector310, vertical column312, casters314, cabinet316, tablet drawer318, connector panel320, control panel322, and ring of information324. Camera stand302may comprise camera326. These components are described in greater with respect toFIG.5.FIG.3illustrates the surgical robot system300in a docked configuration where the camera stand302is nested with the robot301, for example, when not in use. It will be appreciated by those skilled in the art that the camera326and robot301may be separated from one another and positioned at any appropriate location during the surgical procedure, for example, as shown inFIGS.1and2.FIG.4illustrates a base400consistent with an exemplary embodiment of the present disclosure. Base400may be a portion of surgical robot system300and comprise cabinet316. Cabinet316may house certain components of surgical robot system300including but not limited to a battery402, a power distribution module404, a platform interface board module406, a computer408, a handle412, and a tablet drawer414. The connections and relationship between these components is described in greater detail with respect toFIG.5. FIG.5illustrates a block diagram of certain components of an exemplary embodiment of surgical robot system300. Surgical robot system300may comprise platform subsystem502, computer subsystem504, motion control subsystem506, and tracking subsystem532. Platform subsystem502may further comprise battery402, power distribution module404, platform interface board module406, and tablet charging station534. Computer subsystem504may further comprise computer408, display304, and speaker536. Motion control subsystem506may further comprise driver circuit508, motors510,512,514,516,518, stabilizers520,522,524,526, end effector310, and controller538. Tracking subsystem532may further comprise position sensor540and camera converter542. System300may also comprise a foot pedal544and tablet546. Input power is supplied to system300via a power source548which may be provided to power distribution module404. Power distribution module404receives input power and is configured to generate different power supply voltages that are provided to other modules, components, and subsystems of system300. Power distribution module404may be configured to provide different voltage supplies to platform interface module406, which may be provided to other components such as computer408, display304, speaker536, driver508to, for example, power motors512,514,516,518and end effector310, motor510, ring324, camera converter542, and other components for system300for example, fans for cooling the electrical components within cabinet316. Power distribution module404may also provide power to other components such as tablet charging station534that may be located within tablet drawer318. Tablet charging station534may be in wireless or wired communication with tablet546for charging table546. Tablet546may be used by a surgeon consistent with the present disclosure and described herein. Power distribution module404may also be connected to battery402, which serves as temporary power source in the event that power distribution module404does not receive power from input power548. At other times, power distribution module404may serve to charge battery402if necessary. Other components of platform subsystem502may also include connector panel320, control panel322, and ring324. Connector panel320may serve to connect different devices and components to system300and/or associated components and modules. Connector panel320may contain one or more ports that receive lines or connections from different components. For example, connector panel320may have a ground terminal port that may ground system300to other equipment, a port to connect foot pedal544to system300, a port to connect to tracking subsystem532, which may comprise position sensor540, camera converter542, and cameras326associated with camera stand302. Connector panel320may also include other ports to allow USB, Ethernet, HDMI communications to other components, such as computer408. Control panel322may provide various buttons or indicators that control operation of system300and/or provide information regarding system300. For example, control panel322may include buttons to power on or off system300, lift or lower vertical column312, and lift or lower stabilizers520-526that may be designed to engage casters314to lock system300from physically moving. Other buttons may stop system300in the event of an emergency, which may remove all motor power and apply mechanical brakes to stop all motion from occurring. Control panel322may also have indicators notifying the user of certain system conditions such as a line power indicator or status of charge for battery402. Ring324may be a visual indicator to notify the user of system300of different modes that system300is operating under and certain warnings to the user. Computer subsystem504includes computer408, display304, and speaker536. Computer504includes an operating system and software to operate system300. Computer504may receive and process information from other components (for example, tracking subsystem532, platform subsystem502, and/or motion control subsystem506) in order to display information to the user. Further, computer subsystem504may also include speaker536to provide audio to the user. Tracking subsystem532may include position sensor504and converter542. Tracking subsystem532may correspond to camera stand302including camera326as described with respect toFIG.3. Position sensor504may be camera326. Tracking subsystem may track the location of certain markers that are located on the different components of system300and/or instruments used by a user during a surgical procedure. This tracking may be conducted in a manner consistent with the present disclosure including the use of infrared technology that tracks the location of active or passive elements, such as LEDs or reflective markers, respectively. The location, orientation, and position of structures having these types of markers may be provided to computer408which may be shown to a user on display304. For example, a surgical instrument608having these types of markers and tracked in this manner (which may be referred to as a navigational space) may be shown to a user in relation to a three dimensional image of a patient's anatomical structure. Motion control subsystem506may be configured to physically move vertical column312, upper arm306, lower arm308, or rotate end effector310. The physical movement may be conducted through the use of one or more motors510-518. For example, motor510may be configured to vertically lift or lower vertical column312. Motor512may be configured to laterally move upper arm308around a point of engagement with vertical column312as shown inFIG.3. Motor514may be configured to laterally move lower arm308around a point of engagement with upper arm308as shown inFIG.3. Motors516and518may be configured to move end effector310in a manner such that one may control the roll and one may control the tilt, thereby providing multiple angles that end effector310may be moved. These movements may be achieved by controller538which may control these movements through load cells disposed on end effector310and activated by a user engaging these load cells to move system300in a desired manner. Moreover, system300may provide for automatic movement of vertical column312, upper arm306, and lower arm308through a user indicating on display304(which may be a touchscreen input device) the location of a surgical instrument or component on three dimensional image of the patient's anatomy on display304. The user may initiate this automatic movement by stepping on foot pedal544or some other input means. FIG.6illustrates a surgical robot system600consistent with an exemplary embodiment. Surgical robot system600may comprise end effector602, robot arm604, guide tube606, instrument608, and robot base610. Instrument tool608may be attached to a tracking array612including one or more tracking markers (such as markers118) and have an associated trajectory614. Trajectory614may represent a path of movement that instrument tool608is configured to travel once it is positioned through or secured in guide tube606, for example, a path of insertion of instrument tool608into a patient. In an exemplary operation, robot base610may be configured to be in electronic communication with robot arm604and end effector602so that surgical robot system600may assist a user (for example, a surgeon) in operating on the patient210. Surgical robot system600may be consistent with previously described surgical robot system100and300. A tracking array612may be mounted on instrument608to monitor the location and orientation of instrument tool608. The tracking array612may be attached to an instrument608and may comprise tracking markers804. As best seen inFIG.8, tracking markers804may be, for example, light emitting diodes and/or other types of reflective markers (e.g., markers118as described elsewhere herein). The tracking devices may be one or more line of sight devices associated with the surgical robot system. As an example, the tracking devices may be one or more cameras200,326associated with the surgical robot system100,300and may also track tracking array612for a defined domain or relative orientations of the instrument608in relation to the robot arm604, the robot base610, end effector602, and/or the patient210. The tracking devices may be consistent with those structures described in connection with camera stand302and tracking subsystem532. FIGS.7A,7B, and7Cillustrate a top view, front view, and side view, respectively, of end effector602consistent with an exemplary embodiment. End effector602may comprise one or more tracking markers702. Tracking markers702may be light emitting diodes or other types of active and passive markers, such as tracking markers118that have been previously described. In an exemplary embodiment, the tracking markers702are active infrared-emitting markers that are activated by an electrical signal (e.g., infrared light emitting diodes (LEDs)). Thus, tracking markers702may be activated such that the infrared markers702are visible to the camera200,326or may be deactivated such that the infrared markers702are not visible to the camera200,326. Thus, when the markers702are active, the end effector602may be controlled by the system100,300,600, and when the markers702are deactivated, the end effector602may be locked in position and unable to be moved by the system100,300,600. Markers702may be disposed on or within end effector602in a manner such that the markers702are visible by one or more cameras200,326or other tracking devices associated with the surgical robot system100,300,600. The camera200,326or other tracking devices may track end effector602as it moves to different positions and viewing angles by following the movement of tracking markers702. The location of markers702and/or end effector602may be shown on a display110,304associated with the surgical robot system100,300,600, for example, display110as shown inFIG.2and/or display304shown inFIG.3. This display110,304may allow a user to ensure that end effector602is in a desirable position in relation to robot arm604, robot base610, the patient210, and/or the user. For example, as shown inFIG.7A, markers702may be placed around the surface of end effector602so that a tracking device placed away from the surgical field208and facing toward the robot102,301and the camera200,326is able to view at least 3 of the markers702through a range of common orientations of the end effector602relative to the tracking device100,300,600. For example, distribution of markers702in this way allows end effector602to be monitored by the tracking devices when end effector602is translated and rotated in the surgical field208. In addition, in exemplary embodiments, end effector602may be equipped with infrared (IR) receivers that can detect when an external camera200,326is getting ready to read markers702. Upon this detection, end effector602may then illuminate markers702. The detection by the IR receivers that the external camera200,326is ready to read markers702may signal the need to synchronize a duty cycle of markers702, which may be light emitting diodes, to an external camera200,326. This may also allow for lower power consumption by the robotic system as a whole, whereby markers702would only be illuminated at the appropriate time instead of being illuminated continuously. Further, in exemplary embodiments, markers702may be powered off to prevent interference with other navigation tools, such as different types of surgical instruments608. FIG.8depicts one type of surgical instrument608including a tracking array612and tracking markers804. Tracking markers804may be of any type described herein including but not limited to light emitting diodes or reflective spheres. Markers804are monitored by tracking devices associated with the surgical robot system100,300,600and may be one or more of the line of sight cameras200,326. The cameras200,326may track the location of instrument608based on the position and orientation of tracking array612and markers804. A user, such as a surgeon120, may orient instrument608in a manner so that tracking array612and markers804are sufficiently recognized by the tracking device or camera200,326to display instrument608and markers804on, for example, display110of the exemplary surgical robot system. The manner in which a surgeon120may place instrument608into guide tube606of the end effector602and adjust the instrument608is evident inFIG.8. The hollow tube or guide tube114,606of the end effector112,310,602is sized and configured to receive at least a portion of the surgical instrument608. The guide tube114,606is configured to be oriented by the robot arm104such that insertion and trajectory for the surgical instrument608is able to reach a desired anatomical target within or upon the body of the patient210. The surgical instrument608may include at least a portion of a generally cylindrical instrument. Although a screw driver is exemplified as the surgical tool608, it will be appreciated that any suitable surgical tool608may be positioned by the end effector602. By way of example, the surgical instrument608may include one or more of a guide wire, cannula, a retractor, a drill, a reamer, a screw driver, an insertion tool, a removal tool, or the like. Although the hollow tube114,606is generally shown as having a cylindrical configuration, it will be appreciated by those of skill in the art that the guide tube114,606may have any suitable shape, size and configuration desired to accommodate the surgical instrument608and access the surgical site. FIGS.9A-9Cillustrate end effector602and a portion of robot arm604consistent with an exemplary embodiment. End effector602may further comprise body1202and clamp1204. Clamp1204may comprise handle1206, balls1208, spring1210, and lip1212. Robot arm604may further comprise depressions1214, mounting plate1216, lip1218, and magnets1220. End effector602may mechanically interface and/or engage with the surgical robot system and robot arm604through one or more couplings. For example, end effector602may engage with robot arm604through a locating coupling and/or a reinforcing coupling. Through these couplings, end effector602may fasten with robot arm604outside a flexible and sterile barrier. In an exemplary embodiment, the locating coupling may be a magnetically kinematic mount and the reinforcing coupling may be a five bar over center clamping linkage. With respect to the locating coupling, robot arm604may comprise mounting plate1216, which may be non-magnetic material, one or more depressions1214, lip1218, and magnets1220. Magnet1220is mounted below each of depressions1214. Portions of clamp1204may comprise magnetic material and be attracted by one or more magnets1220. Through the magnetic attraction of clamp1204and robot arm604, balls1208become seated into respective depressions1214. For example, balls1208as shown inFIG.9Bwould be seated in depressions1214as shown inFIG.9A. This seating may be considered a magnetically-assisted kinematic coupling. Magnets1220may be configured to be strong enough to support the entire weight of end effector602regardless of the orientation of end effector602. The locating coupling may be any style of kinematic mount that uniquely restrains six degrees of freedom. With respect to the reinforcing coupling, portions of clamp1204may be configured to be a fixed ground link and as such clamp1204may serve as a five bar linkage. Closing clamp handle1206may fasten end effector602to robot arm604as lip1212and lip1218engage clamp1204in a manner to secure end effector602and robot arm604. When clamp handle1206is closed, spring1210may be stretched or stressed while clamp1204is in a locked position. The locked position may be a position that provides for linkage past center. Because of a closed position that is past center, the linkage will not open absent a force applied to clamp handle1206to release clamp1204. Thus, in a locked position end effector602may be robustly secured to robot arm604. Spring1210may be a curved beam in tension. Spring1210may be comprised of a material that exhibits high stiffness and high yield strain such as virgin PEEK (poly-ether-ether-ketone). The linkage between end effector602and robot arm604may provide for a sterile barrier between end effector602and robot arm604without impeding fastening of the two couplings. The reinforcing coupling may be a linkage with multiple spring members. The reinforcing coupling may latch with a cam or friction based mechanism. The reinforcing coupling may also be a sufficiently powerful electromagnet that will support fastening end-effector102to robot arm604. The reinforcing coupling may be a multi-piece collar completely separate from either end effector602and/or robot arm604that slips over an interface between end effector602and robot arm604and tightens with a screw mechanism, an over center linkage, or a cam mechanism. Referring toFIGS.10and11, prior to or during a surgical procedure, certain registration procedures may be conducted in order to track objects and a target anatomical structure of the patient210both in a navigation space and an image space. In order to conduct such registration, a registration system1400may be used as illustrated inFIG.10. In order to track the position of the patient210, a patient tracking device116may include a patient fixation instrument1402to be secured to a rigid anatomical structure of the patient210and a dynamic reference base (DRB)1404may be securely attached to the patient fixation instrument1402. For example, patient fixation instrument1402may be inserted into opening1406of dynamic reference base1404. Dynamic reference base1404may contain markers1408that are visible to tracking devices, such as tracking subsystem532. These markers1408may be optical markers or reflective spheres, such as tracking markers118, as previously discussed herein. Patient fixation instrument1402is attached to a rigid anatomy of the patient210and may remain attached throughout the surgical procedure. In an exemplary embodiment, patient fixation instrument1402is attached to a rigid area of the patient210, for example, a bone that is located away from the targeted anatomical structure subject to the surgical procedure. In order to track the targeted anatomical structure, dynamic reference base1404is associated with the targeted anatomical structure through the use of a registration fixture that is temporarily placed on or near the targeted anatomical structure in order to register the dynamic reference base1404with the location of the targeted anatomical structure. A registration fixture1410is attached to patient fixation instrument1402through the use of a pivot arm1412. Pivot arm1412is attached to patient fixation instrument1402by inserting patient fixation instrument1402through an opening1414of registration fixture1410. Pivot arm1412is attached to registration fixture1410by, for example, inserting a knob1416through an opening1418of pivot arm1412. Using pivot arm1412, registration fixture1410may be placed over the targeted anatomical structure and its location may be determined in an image space and navigation space using tracking markers1420and/or fiducials1422on registration fixture1410. Registration fixture1410may contain a collection of markers1420that are visible in a navigational space (for example, markers1420may be detectable by tracking subsystem532). Tracking markers1420may be optical markers visible in infrared light as previously described herein. Registration fixture1410may also contain a collection of fiducials1422, for example, such as bearing balls, that are visible in an imaging space (for example, a three dimension CT image). As described in greater detail with respect toFIG.11, using registration fixture1410, the targeted anatomical structure may be associated with dynamic reference base1404thereby allowing depictions of objects in the navigational space to be overlaid on images of the anatomical structure. Dynamic reference base1404, located at a position away from the targeted anatomical structure, may become a reference point thereby allowing removal of registration fixture1410and/or pivot arm1412from the surgical area. FIG.11provides an exemplary method1500for registration consistent with the present disclosure. Method1500begins at step1502wherein a graphical representation (or image(s)) of the targeted anatomical structure may be imported into system100,300600, for example computer408. The graphical representation may be three dimensional CT or a fluoroscope scan of the targeted anatomical structure of the patient210which includes registration fixture1410and a detectable imaging pattern of fiducials1420. At step1504, an imaging pattern of fiducials1420is detected and registered in the imaging space and stored in computer408. Optionally, at this time at step1506, a graphical representation of the registration fixture1410may be overlaid on the images of the targeted anatomical structure. At step1508, a navigational pattern of registration fixture1410is detected and registered by recognizing markers1420. Markers1420may be optical markers that are recognized in the navigation space through infrared light by tracking subsystem532via position sensor540. Thus, the location, orientation, and other information of the targeted anatomical structure is registered in the navigation space. Therefore, registration fixture1410may be recognized in both the image space through the use of fiducials1422and the navigation space through the use of markers1420. At step1510, the registration of registration fixture1410in the image space is transferred to the navigation space. This transferal is done, for example, by using the relative position of the imaging pattern of fiducials1422compared to the position of the navigation pattern of markers1420. At step1512, registration of the navigation space of registration fixture1410(having been registered with the image space) is further transferred to the navigation space of dynamic registration array1404attached to patient fixture instrument1402. Thus, registration fixture1410may be removed and dynamic reference base1404may be used to track the targeted anatomical structure in both the navigation and image space because the navigation space is associated with the image space. At steps1514and1516, the navigation space may be overlaid on the image space and objects with markers visible in the navigation space (for example, surgical instruments608with optical markers804). The objects may be tracked through graphical representations of the surgical instrument608on the images of the targeted anatomical structure. FIGS.12A-12Billustrate imaging devices1304that may be used in conjunction with robot systems100,300,600to acquire pre-operative, intra-operative, post-operative, and/or real-time image data of patient210. Any appropriate subject matter may be imaged for any appropriate procedure using the imaging system1304. The imaging system1304may be any imaging device such as imaging device1306and/or a C-arm1308device. It may be desirable to take x-rays of patient210from a number of different positions, without the need for frequent manual repositioning of patient210which may be required in an x-ray system. As illustrated inFIG.12A, the imaging system1304may be in the form of a C-arm1308that includes an elongated C-shaped member terminating in opposing distal ends1312of the “C” shape. C-shaped member1130may further comprise an x-ray source1314and an image receptor1316. The space within C-arm1308of the arm may provide room for the physician to attend to the patient substantially free of interference from x-ray support structure1318. As illustrated inFIG.12B, the imaging system may include imaging device1306having a gantry housing1324attached to a support structure imaging device support structure1328, such as a wheeled mobile cart1330with wheels1332, which may enclose an image capturing portion, not illustrated. The image capturing portion may include an x-ray source and/or emission portion and an x-ray receiving and/or image receiving portion, which may be disposed about one hundred and eighty degrees from each other and mounted on a rotor (not illustrated) relative to a track of the image capturing portion. The image capturing portion may be operable to rotate three hundred and sixty degrees during image acquisition. The image capturing portion may rotate around a central point and/or axis, allowing image data of patient210to be acquired from multiple directions or in multiple planes. Although certain imaging systems1304are exemplified herein, it will be appreciated that any suitable imaging system may be selected by one of ordinary skill in the art. Referring now toFIGS.13A-15of the present disclosure, exemplary embodiments of a surveillance marker consistent with the present disclosure are illustrated.FIGS.13A-13Bdepicts a system2000including a surveillance maker2002, a dynamic reference base (DRB)2004, which may be a tracking array having array markers2006, a DRB post2008, and a surveillance marker post2010. Also depicted is a patient's bone2012. In this configuration, surveillance marker2002is on surveillance marker post2010that is within the hollow center or channel of the main shaft of the DRB post2008. Surveillance marker post2010could consist of hard metal with a sharp, smooth tip for driving into bone with a mallet, or an end-threaded tip for drilling into bone. If DRB2004is bumped or dislodged, the tracking array with array markers2006would shift relative to the position of surveillance marker2002despite the close proximity of the spikes holding DRB2004to bone2012and the tip of the surveillance post2010for the surveillance marker2002. Post2010to which surveillance marker2002is mounted is within the hollow main shaft of a spike or clamp to which DRB2004is mounted. There may be a loose tolerance between the wall of the hollow main shaft of DRB post2008and surveillance marker post2010. In the exemplary embodiment ofFIG.13A, with surveillance marker post2010encompassed by DRB post2008, dislodgment and bending movement of DRB2004may cause DRB2004to press against surveillance marker post2010and cause it to move as well. However, since the attachment or entry point to bone2012is different for DRB post2008and surveillance marker post2010, the axis of rotation of surveillance marker post2010and DRB2004may differ, meaning there may be a detectable change in position of surveillance marker2002relative to DRB2004even if the two structures touch. The amount of relative shift in position of surveillance marker2002and tracking markers2006if DRB2004is bumped may be greatest if surveillance marker post2010does not touch the inside wall of the hollow shaft of DRB post2008. It may be beneficial to have a loose tolerance between surveillance marker post2010and inside wall of the DRB post2010for a more easily detectable effect. It may also be beneficial to at least begin surveillance with a condition where surveillance marker post2010is not touching the hollow wall of DRB post2004, even if it will eventually touch during bending. To help ensure that surveillance marker post2010is not touching the hollow wall of DRB post2008during insertion, it may be beneficial to use a temporary centering guide such as a doughnut-shaped piece, through which surveillance marker post2008is inserted and which forces the surveillance marker post to the midline of the hollow shaft. After the post is inserted, the guide could be removed so that there remains loose tolerance between the hollow wall of the DRB post2008and surveillance marker post2010. Such a guide could be used at the top of the DRB's tube region, at the bottom of the tube region, or both. FIG.13Bis another configuration of system2000with surveillance marker2002offset from the midline of DRB post2008. This configuration may avoid inadvertent rotation of the clamped DRB2004about the axis of the shaft when bumped. Such rotation may occur if clamp2014holding DRB2004in place is not sufficiently tightened and DRB2004is disturbed, even slightly. In the exemplary embodiment ofFIG.13A, if rotation of DRB2004about DRB post2008occurred without any travel of DRB2004longitudinally along DRB post2008, there may be minimal or undetectable relative movement of surveillance marker2002during rotational dislodgement since the position of surveillance marker2002is on or close to the axis of rotation of DRB2004rotational movement. In this event, surveillance marker2002may be offset from the midline or longitudinal axis of DRB post2008(for example by 1 cm or more), as shown inFIG.13B. In this configuration, even a slight rotation of DRB2004about its mounting shaft would be detectable relative to the unmoved surveillance marker2002, since surveillance marker2002is not on the axis of rotation of DRB2004. This configuration may also give a distal region on surveillance marker post2010that can serve as the head to be struck with a hammer for driving it into bone, or a region to clamp in the chuck of a drill if it is to be drilled into bone. If surveillance marker2002is attached centrally to post2010, a cap or other feature may be added to allow it to be inserted without damaging the surface of surveillance marker2002, which may be coated with reflective paint. Additionally, during insertion, this configuration may allow surveillance marker2002to be manually rotated and positioned pointing toward the tracking cameras for better visibility. FIGS.14A-Billustrates an exemplary embodiment of a system2100that includes some components as previously described. System2100also includes a temporary grouping element2102. In system2100, surveillance marker2002may be attached through the same incision into a patient, but not physically connected to DRB2004or DRB post2008. One manner to do this may be to use temporary grouping element2102to hold surveillance post2010and DRB post2008so that these components may be inserted as a unit. These components may then become independent after temporary grouping element2102is removed as shown inFIG.14B. InFIG.14A, DRB post2008and surveillance marker post2010may be inserted into bone2012simultaneously while being held together at a desired spacing with temporary grouping element2102. After DRB post2008and surveillance marker post2010have been inserted, temporary grouping element2102may be removed, and DRB2004and surveillance marker2002may be attached, which may be anchored in independent pieces of bone. Temporary grouping element2102may also be an impaction cap to be struck by a hammer during insertion. FIG.15illustrates an exemplary embodiment2200. In this configuration it may be possible to attach surveillance marker2002through the same incision of the patient but not physically connected to DRB2004. InFIG.15, different insertion angles may be used, with trajectories of the surveillance marker post2010and DRB post2008within the same incision (not shown). The attachment of surveillance marker2002as described with regard toFIGS.13-15may allow application of a surveillance marker, which has demonstrated benefits, through a single incision instead of requiring multiple incisions which may result in less time in surgery and less discomfort for the patient. Now turning toFIGS.16A and16B, there is shown a surveillance marker2020that is used to detect any change of position of the dynamic reference base (DRB)2024, which is critical for navigational accuracy. In some situations, the surveillance marker2020may not be able to detect a position change correctly if a DRB rotates along an axis2026, and the surveillance marker2020is close to or on the axis of rotation2026. The change of position appears as a rotation of the surveillance marker2020, which does not register as a position change, since the surveillance marker2020is a configured as a sphere. The surveillance marker2020as illustrated inFIGS.16A and16B, uses a single optical marker2028, typically a sphere, ‘registered’ to the DRB2024. Both surveillance marker and DRB are securely attached to bony anatomy with a separate post or spike. The position of the surveillance marker is tracked with respect to the DRB2024coordinate system, so that any shift or rotation of the DRB2024(or any shift of the surveillance marker) can be detected, even if the camera is moved. This scheme works well in any situation involving a purely translational shift. FIGS.16A and16Bshow how a single surveillance marker fails to detect the rotation of an array on a DRB if the DRB mounts to the patient with a hinge mechanism and the hinge's axis of rotation intersects the surveillance marker. However, if more than one surveillance marker is used, the system can successfully detect a rotation, if the axis of rotation of the DRB does not pass through all the surveillance markers. In one exemplary embodiment, this mechanism would utilize two optical markers on the surveillance instrument, which could attach to the same post as shown inFIGS.17A and17Bto minimize surgical incisions or mounted to different posts. In this embodiment, a surveillance marker2030is provided with at least two optical markers2032,2034. The system could use the relative distance between each of optical markers2032,2034and the DRB, or between the line formed by the two markers2032,2034and the DRB markers, to calculate the amount of shift. Surveillance markers mounted to a post vertically or mostly vertically as shown inFIG.17will most likely not both be collinear with a hinge that is oriented horizontally. In other embodiments, three or more markers may be used to create accuracy through redundancy. Now turning toFIG.18, in a preferred embodiment, the system through a software element may alert the user that a single surveillance marker2040is in close proximity to the axis of rotation of the DRB2042if the location of the DRB's hinge2044is known relative to the tracked markers of the DRB2042and hinge location is extrapolated and compared to the surveillance marker position2040. If the surveillance marker2040is close to the hinge, for example in one embodiment less than 25 mm from the hinge, the system can alert the user to move the surveillance marker or use a secondary method such as landmark check to test whether there is any rotational movement. Similarly, the system can alert the user if dual surveillance markers form a line that is close to being collinear with the hinge of the DRB. In another embodiment, the system provides a method of ensuring that the DRB hinge does not intersect the surveillance marker by restricting where the user can mount the surveillance marker to force the surveillance marker to be located away from the DRB's hinge. In one particular embodiment, a collar clamp on the DRB shaft with a small post present for the attachment of a single surveillance marker is used (FIG.3). There are markings provided on the DRB shaft and physical stops along the shaft or collar, or in another embodiment a wide collar clamp design ensure that the surveillance marker is never able to be mounted far enough up the shaft that it would approach the location of the hinge. In another embodiment, there is a provided a method of preventing the surveillance marker from approaching the hinge. A temporary guide tube is utilized wherein the temporary guide tube has a minimum allowable radius to the hinge during setup, blocking the user from placing the surveillance marker within that radius of the hinge. In yet another embodiment, a chain or other tether to the base of the DRB with the surveillance marker attached to the other end could be used that will not allow the surveillance marker to approach the hinge location. When the DRB is displaced either accidentally or by need, the present system provides a method of monitoring skin movement. In one embodiment, the skin may be marked with ink2040or any other bio-compatible material or a second surveillance marker may be attached to the skin (FIG.3). If a first surveillance marker is already near the skin, like in the previous, embodiment, the mark on the skin can be placed very near the post-mounted marker. The system would be able to use the first surveillance marker mounted to the DRB post to track DRB shift and rotation, while the surgeon would visually monitor the patient's skin mark to track shift (tugging) of the skin immediately surrounding the DRB. The close proximity of the skin mark or the second surveillance market to the first surveillance marker makes it is easier to visualize for the surgeon to discern a shift. If the surgeon suspected that the ink mark or the second surveillance marker has shifted, the surgeon or user can point to the skin mark or the second surveillance marker with a tracked probe to determine how much it had moved relative to the location of the probe at the beginning of the case. If a tracked marker on the skin is used, this marker can continuously monitor the relationship between the DRB post and the skin to assess whether there is offset. The above embodiments provide the advantage of tracking the shift in the surveillance marker relative to the DRB even in the cases where the shift is in the surveillance marker. In addition, multiple surveillance markers provide redundancy to the system when line of sight is compromised. Now turning to another embodiment in which the system provides method for recovery of registration from DRBs and single optical markers. As discussed earlier, when navigating using a surgical robotic system, continuous tracking of a DRB array that is attached to the patient is required to determine the position of any navigated instrument or tool relative to the patient's anatomy. Under certain conditions, the DRB may sometimes be partially obscured thereby making the DRB untrackable. In other situations, the DRB may be dislodged from its mounting point on the bone, also making it untrackable. When the DRB is partially obstructed, tracking or navigating must be paused and the camera system modified to restore line of sight to the markers on the DRB. When the DRB is dislodged, a new imaging scan is required and registration of the patient to the camera coordinate system is done. The present system provides a method to recover the registration or enables the continual tracking of optical makers of the surgical robot and the one or more markers mounted elsewhere on the patient. Registration is synchronization of two coordinate systems, typically the tracking coordinate system, such as the coordinate space tracked by an optical system such as the Polaris Spectra (Northern Digital, Inc.), and the image coordinate system such as the coordinate system of a computed tomography (CT) scan. Registration is accomplished when the rigid body transformation to get from one coordinate system to the other is known. To achieve 3D registration, at least 3 reference points on a rigid body that is observed simultaneously in each coordinate system are found and the transformation of coordinates necessary to move the 3 reference points from one coordinate system to their corresponding coordinates in the other coordinate system is calculated. For example, if a tracking fixture has optical tracking markers that are in a known location (known from engineering design or located by any experimental means) in the fixture's local coordinate system and these tracking markers' xyz locations are tracked by the cameras, the transformation from camera coordinate system to fixture coordinate system can be calculated. In the field of 3D rigid body mechanics, transformations between coordinate systems are applied by multiplying each point to be transformed by a 4×4 transformation matrix. In such matrices, the first three columns describe the orientation of the rigid body and the 4th column describes the translational offset. The transformation matrix from the camera coordinate system to the fixture coordinate system may be represented as: TCamera-Fixture And to transform a point P from the camera coordinate system to the fixture coordinate system is represented as: PFixture=TCamera-Fixture×Pcamera There are provided several different methods for determining the 4×4 transformation matrix from sets of the same points in two coordinate systems. For example, the Kabsch algorithm is a method for calculating the optimal transformation matrix that minimizes the RMSD (root mean squared deviation) between two paired sets of points. Transformation matrices may be easily combined to achieve new useful transformation matrices. In one embodiment, the fixture described above may contain fiducials for detection within a CT volume. If the locations of these fiducials are known in the local coordinate system of the fixture, the transformation of coordinates from fixture to CT image coordinate system can be found as TFixture-Imageusing the Kabsch or similar algorithm. As a result, the transformation results from the camera coordinate system to the coordinate system of the medical image can be determined by combining two transformations: TCamera-Image=TCamera-Fixture×TFixture-Image If the DRB is dislodged, the relationship between fiducials and the CT are no longer the same as at the time the CT scan was taken, as a result the TFixture-Imageis incorrect and TCamera-Imageis not valid. In a preferred embodiment, a tracking array positioned on an end effector provides the location of the end effector in the coordinate system of the cameras. The robot system is equipped with encoders on each axis that precisely monitor the positions of each linkage of the robot arm. As the robot arm is moved, the position of the end effector is detected from tracking markers, but the positional change may also be calculated from kinematics by considering the geometry of each joint of the robotic arm and the amount of movement on each joint as monitored by the rotational or linear encoders. This ability to reference points in the tracking coordinate system from kinematic information provides an additional transformation calculation that can be utilized: the transformation from current tracked coordinates of the robot's end effector to a fixed reference in the camera coordinate system. That is, a frame of tracking data provides a snapshot of the tracked position of the robot end effector, but through a transformation derived from the axis encoder readings that account for the change in position due to movement of the joints, this moving frame of data can be transformed into the fixed reference frame of the robot despite any movement of the patient or camera that may occur. This transformation allows the moving array on the end effector to function the same as if another array were physically mounted to the base of the robot to track its position. TCamera-RobotBase=TCamera-EndEffector×TEndEffector-RobotBase As described in a previous embodiment a surveillance marker is used to continuously monitor the integrity of the DRB's attachment to bone. If the patient moves, both the DRB and the surveillance marker would move together without changing their relative position, but if the DRB or surveillance marker is dislodged, the relative position would change. In another embodiment, a method for recovering the registration that is based on the last known position of the DRB relative to the robot is provided. The system continuously updates the last valid location of the DRB relative to the robot base and stores this location in system memory for later usage if necessary. If the DRB becomes dislodged by inadvertent contact with medical personnel or equipment, the surveillance marker would show a change in offset of the DRB markers and would positively indicate that movement had occurred. If tracking data also shows that the distance between the robot's fixed reference frame and the surveillance marker on the patient have not moved, it can be safely assumed that the patient has not moved relative to the robot. As a result, the DRB may be reattached and a new registration established based on the tracked position of the robot. To establish a new registration, the new position of the DRB and robot's array would be tracked simultaneously, giving the transformation calculation from the end effector to the new DRB position. Additionally, the last known DRB location in the coordinate system of the robot would be recalled from the memory storage device. The new registration can therefore be established as: TCamera-Image=TCamera-RobotEE×TRobotEE-RobotBase×TRobotBase-LastKnownDRB×TLastKnownDRB-Image With the new DRB attachment, the following is also true: TCamera-Image=TCamera-DRB×TDRB-Image Setting the two equations equal to each other, the transformation from new location of the DRB to the image can be determined as TDRB-Image=TDRB-Camera×TCamera-RobotEE×TRobotEE-RobotBase×TRobotBase-LastKnownDRB×TLastKnownDRB−Image During collection of the new location of the DRB in the camera coordinate system, the location of the surveillance marker relative to the robot base would be continuously measured to ensure that the surveillance marker has not moved since before the DRB was dislodged. In another embodiment, if there is movement of the surveillance marker or movement of both the surveillance marker and the DRB at the time of dislodgment, a new scan and registration would be required. In another embodiment, the system provides a method for re-registering the patient when there is a partial obstruction of the DRB to where only 2 of the 4 optical markers on the DRB remain visible while 2 optical markers are blocked. If the robot is movement when there is a partial obstruction, the motion of the robot arm is stopped until the DRB becomes fully visualized by the camera system, or if a tool or instrument is being tracked, the tool or instrument would freeze in its display on the screen. However, the system will track the DRB, if the surveillance marker remains visible. The two visible optical markers of the DRB and the surveillance marker comprise 3 points, which is the minimum points to define a rigid body. If the distances of the surveillance marker relative to the two visible points have not changed, the DRB has not moved in bone. From any previous frame of data where all markers on the DRB were visible, the transformation of the surveillance marker into the DRB coordinate system could have been determined by applying the transformation from camera to DRB to the tracked position of the surveillance marker. This value is stored to the system memory. After the optical markers on the DRB are blocked, the 2 blocked optical markers can be “reconstructed” by applying a point matching algorithm where one point set is the tracked xyz coordinates of the two DRB optical markers plus the surveillance marker and the corresponding point set to be matched is the same two DRB markers and the surveillance marker in the coordinate system of the DRB. For example, Point set 1={Visible DRB marker 1,Visible DRB marker 2,Surveillance marker}DRB Point set 2={Visible DRB marker 1,Visible DRB marker 2,Surveillance marker}CameraTDRB-Camera The reconstructed DRB markers are determined as this transformation applied to the known locations of the missing DRB markers in the DRB coordinate system: PBlockedDRBmarker1,Camera=TDRB-Camera×PBlockedDRBmarker1,DRB PBlockedDRBmarker2,Camera=TDRB-Camera×PBlockedDRBmarker2,DRB Using a full set of the two previously visible DRB optical markers plus the two reconstructed markers, the normal sequence of transformations can be applied and standard tracking methods followed. While the invention has been disclosed in connection with the preferred embodiments shown and described in detail, various modifications and improvements thereon will become readily apparent to those skilled in the art. Accordingly, the spirit and scope of the present invention is not to be limited by the foregoing examples, but is to be understood in the broadest sense allowable by law.

11857267

Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. DETAILED DESCRIPTION Example embodiments will now be described more fully with reference to the accompanying drawings. Disclosed herein are exemplary embodiments, as discussed further herein. Generally, various embodiments may be disclosed relative to a human subject. It is understood, however, that various disclosed systems, such as navigation or tracking systems, may be used relative to any subject or system that may have an outer hull or shell that may encompass internal components or operations. For example, an air frame or automobile frame may obscure internal components, which may be selected to be operated on in a selected procedure. The selected procedure may include removal, replacement, or the like of various components of any non-animate or inanimate system. Accordingly, it is understood that a discussion herein relative to a subject, such as a human subject, is merely exemplary. Further, as discussed herein, a navigation system may include tracking various components, such as an instrument, relative to a reference frame within a coordinate system or space. In various embodiments, the coordinate space may include a subject coordinate space or a real space defined by real space relative to the subject. Additional coordinate spaces may include image space that has an image coordinate space defined an image of the subject. A pose of an instrument, as discussed above that may include a position and orientation of the instrument, may be illustrated relative to, for example superimposed on, the image with a graphical representation for viewing by a user. Such illustrations may require or use registration between a subject space or subject coordinate space and an image coordinate space or image space. A method to register a subject space defined by a subject to an image space may include those disclosed in U.S. Pat. Nos. 8,737,708; 9,737,235; 8,503,745; and 8,175,681; all incorporated herein by reference. FIG.1, according to various embodiments, is a diagrammatic view illustrating an overview of a procedure room or arena. In various embodiments, the procedure room may include a surgical suite. The surgical suite may include a navigation system26that can be used for various procedures, such as those relative to a subject30. The navigation system26can be used to track the pose of one or more tracking devices, and the tracking devices may include a subject tracking device or dynamic reference frame (DRF)58, an imaging system tracking device62, and/or a tool tracking device66. It is understood that other tracking devices may also be included, such as a user or clinician tracking device alone or in combination with other systems (e.g. augmented reality systems). A tool68may be any appropriate tool such as a drill, forceps, or other tool operated by a user72. The tool68may also include an implant, such as a spinal implant or orthopedic implant. It should further be noted that the navigation system26may be used to navigate any type of instrument, implant, or delivery system, including: guide wires, arthroscopic systems, orthopedic implants, spinal implants, deep brain stimulation (DBS) probes, etc. Moreover, the instruments may be used to navigate or map any region of the body. The navigation system26and the various instruments may be used in any appropriate procedure, such as one that is generally minimally invasive or an open procedure. An imaging device80may be used to acquire pre-, intra-, or post-operative or real-time image data of a subject, such as the subject30. It will be understood, however, that any appropriate subject can be imaged and any appropriate procedure may be performed relative to the subject. In the example shown, the imaging device80comprises an O-Arm® imaging device sold by Medtronic Navigation, Inc. having a place of business in Louisville, Colorado, USA. The imaging device80may have a generally annular gantry housing82in which an image capturing portion is moveably placed. The image capturing portion may include an x-ray source or emission portion and an x-ray receiving or image receiving portion located generally or as practically possible 180 degrees from each other and mounted on a rotor relative to a track or rail. The image capturing portion can be operable to rotate 360 degrees during image acquisition. The image capturing portion may rotate around a central point or axis, allowing image data of the subject30to be acquired from multiple directions or in multiple planes. The imaging device80can include those disclosed in U.S. Pat. Nos. 7,188,998; 7,108,421; 7,106,825; 7,001,045; and 6,940,941; all of which are incorporated herein by reference, or any appropriate portions thereof. In one example, the imaging device80can utilize flat plate technology having a 1,720 by 1,024 pixel viewing area. The position of the imaging device80, and/or portions therein such as the image capturing portion, can be precisely known relative to any other portion of the imaging device80. The imaging device80, according to various embodiments, can know and recall precise coordinates relative to a fixed or selected coordinate system. This can allow the imaging system80to know its position relative to the patient30or other references. In addition, as discussed herein, the precise knowledge of the position of the image capturing portion can be used in conjunction with a tracking system to determine the position of the image capturing portion and the image data relative to the tracked subject, such as the patient30. The imaging device80can also be tracked with the image tracking device62. The image data defining an image space acquired of the patient30can, according to various embodiments, be inherently or automatically registered relative to an object space. The object space can be the space defined by a patient30in the navigation system26. The automatic registration can be achieved by including the tracking device62on the imaging device80and/or the determinable precise pose of the image capturing portion. According to various embodiments, as discussed herein, imageable portions, virtual fiducial points and other features can also be used to allow for registration, automatic or otherwise. It will be understood, however, that image data can be acquired of any subject which will define subject space. Patient space is an exemplary subject space. Registration allows for a map between patient space and image space. The patient30can also be tracked as the patient moves with the patient tracking device, DRF, or tracker58. Alternatively, or in addition thereto, the patient30may be fixed within navigation space defined by the navigation system26to allow for registration. As discussed further herein, registration of the image space to the patient space or subject space allows for navigation of the instrument68with the image data. When navigating the instrument68, a pose of the instrument68can be illustrated relative to image data acquired of the patient30on a display device84. Various tracking systems, including at least one of an optical localizer88or an electromagnetic (EM) localizer94, can be used to track the instrument68. As discussed herein, in various embodiments, the localizer94may transmit a signal that is received by the tracking device66, or other appropriate tracking device. In addition, an appropriate antenna, e.g. a coil, may also be provided as a received. For example, a calibration receiver95(e.g. a coil) may be provided to receive a signal form the localizer94. The calibration receiver95may be included in any appropriate portion of the navigation system26, such as a controller110, as discussed further herein. It is understood by one skilled in the art that the calibration receiver95need not be incorporated into the navigation system26during a use, but may be provided or used during an initial (e.g. factory) production or calibration of the navigation system26. In various embodiments, the calibration receiver95may receive the signal from the localizer94in a manner similar to the tracking device66and be used for various purposes, as discussed herein. More than one tracking system can be used to track the instrument68in the navigation system26. According to various embodiments, tracking systems can include an electromagnetic tracking (EM) system having the EM localizer94and/or an optical tracking system having the optical localizer88. Either or both of the tracking systems can be used to tracked selected tracking devices, as discussed herein. It will be understood, unless discussed otherwise, that a tracking device can be a portion trackable with a selected tracking system. A tracking device need not refer to the entire member or structure to which the tracking device is affixed or associated. It is further appreciated that the imaging device80may be an imaging device other than the O-Arm® imaging device and may include in addition or alternatively a fluoroscopic C-arm. Other exemplary imaging devices may include fluoroscopes such as bi-plane fluoroscopic systems, ceiling mounted fluoroscopic systems, cath-lab fluoroscopic systems, fixed C-arm fluoroscopic systems, isocentric C-arm fluoroscopic systems, 3D fluoroscopic systems, etc. Other appropriate imaging devices can also include MRI, CT, ultrasound, etc. In various embodiments, an imaging device controller96may control the imaging device80and can receive the image data generated at the image capturing portion and store the images for later use. The controller96can also control the rotation of the image capturing portion of the imaging device80. It will be understood that the controller96need not be integral with the gantry housing82, but may be separate therefrom. For example, the controller may be a portion of the navigation system26that may include a processing and/or control system98including a processing unit or processing portion102. The controller96, however, may be integral with the gantry82and may include a second and separate processor, such as that in a portable computer. The patient30can be positioned, including fixed, on an operating table104. According to one example, the table104can be an Axis Jackson® operating table sold by OSI, a subsidiary of Mizuho Ikakogyo Co., Ltd., having a place of business in Tokyo, Japan or Mizuho Orthopedic Systems, Inc. having a place of business in California, USA. Patient positioning devices can be used with the table, and include a Mayfield® clamp or those set forth in U.S. Pat. App. Pub. No. 2004/0199072, published Oct. 7, 2004 (U.S. patent application Ser. No. 10/405,068) entitled “An Integrated Electromagnetic Navigation And Patient Positioning Device”, which is hereby incorporated by reference. The position of the patient30relative to the imaging device80can be determined by the navigation system26. The tracking device62can be used to track and determine a pose of at least a portion of the imaging device80, for example the gantry or housing82. The patient30can be tracked with the dynamic reference frame58, as discussed further herein. Accordingly, the position of the patient30relative to the imaging device80can be determined. Further, the pose of the imaging portion can be determined relative to the housing82due to its precise position on the rail within the housing82, substantially inflexible rotor, etc. The imaging device80can include an accuracy of within 10 microns, for example, if the imaging device80is an O-Arm® imaging device sold by Medtronic Navigation, Inc. having a place of business in Louisville, Colorado Precise positioning of the imaging portion is further described in U.S. Pat. Nos. 7,188,998; 7,108,421; 7,106,825; 7,001,045; and 6,940,941; all of which are incorporated herein by reference, According to various embodiments, the imaging device80can generate and/or emit x-rays from the x-ray source that propagate through the patient30and are received by the x-ray imaging receiving portion. The image capturing portion generates image data representing the intensities of the received x-rays. Typically, the image capturing portion can include an image intensifier that first converts the x-rays to visible light and a camera (e.g. a charge-coupled device) that converts the visible light into digital image data. The image capturing portion may also be a digital device that converts x-rays directly to digital image data for forming images, thus potentially avoiding distortion introduced by first converting to visible light. Two dimensional and/or three dimensional fluoroscopic image data that may be taken by the imaging device80can be captured and stored in the imaging device controller96. Multiple image data taken by the imaging device80may also be captured and assembled to provide a larger view or image of a whole region of a patient30, as opposed to being directed to only a portion of a region of the patient30. For example, multiple image data of the patient's30spine may be appended together to provide a full view or complete set of image data of the spine. The image data can then be forwarded from the image device controller96to the navigation computer and/or processor system102that can be a part of a controller or work station98having the display84and a user interface106. It will also be understood that the image data is not necessarily first retained in the controller96, but may also be directly transmitted to the work station98. The work station98can provide facilities for displaying the image data as an image108on the display84, saving, digitally manipulating, or printing a hard copy image of the received image data. The user interface106, which may be a keyboard, mouse, touch pen, touch screen or other suitable device, allows the user72to provide inputs to control the imaging device80, via the image device controller96, or adjust the display settings of the display84. The work station98may also direct the image device controller96to adjust the image capturing portion of the imaging device80to obtain various two-dimensional images along different planes in order to generate representative two-dimensional and three-dimensional image data. With continuing reference toFIG.1, the navigation system26can further include the tracking system including either or both of the electromagnetic (EM) localizer94and/or the optical localizer88. The tracking systems may include the controller and interface portion110. The controller110can be connected to the processor portion102, which can include a processor included within a computer. The EM tracking system may include the STEALTHSTATION® AXIEM™ Navigation System, sold by Medtronic Navigation, Inc. having a place of business in Louisville, Colorado; or can be the EM tracking system described in U.S. patent application Ser. No. 10/941,782, filed Sep. 15, 2004, and entitled “METHOD AND APPARATUS FOR SURGICAL NAVIGATION”; U.S. Pat. No. 5,913,820, entitled “Position Location System,” issued Jun. 22, 1999; and U.S. Pat. No. 5,592,939, entitled “Method and System for Navigating a Catheter Probe,” issued Jan. 14, 1997; all of which are herein incorporated by reference. It will be understood that the navigation system26may also be or include any appropriate tracking system, including a STEALTHSTATION® TREON® or S7™ tracking systems having an optical localizer, that may be used as the optical localizer88, and sold by Medtronic Navigation, Inc. of Louisville, Colorado Other tracking systems include an acoustic, radiation, radar, etc. The tracking systems can be used according to generally known or described techniques in the above incorporated references. Details will not be included herein except when to clarify selected operation of the subject disclosure. Wired or physical connections can interconnect the tracking systems, imaging device80, etc. Alternatively, various portions, such as the instrument68may employ a wireless communications channel, such as that disclosed in U.S. Pat. No. 6,474,341, entitled “Surgical Communication Power System,” issued Nov. 5, 2002, herein incorporated by reference, as opposed to being coupled directly to the controller110. Also, the tracking devices62,66, can generate a field and/or signal that is sensed by the localizer(s)88,94. In various embodiments, the instrument tracking device66, and/or other appropriate tracking devices, may communicate with a wireless signal113, as discussed herein, with the controller110and/or the array94. In various embodiments, the array94may operate with a spread spectrum signal to communicate with the tracking device66. Various portions of the navigation system26, such as the instrument68, and others as will be described in detail below, can be equipped with at least one, and generally multiple, of the tracking devices66. The instrument can also include more than one type or modality of tracking device66, such as an EM tracking device and/or an optical tracking device. The instrument68can include a graspable or manipulable portion at a proximal end and the tracking devices may be fixed near the manipulable portion of the instrument68. It is understood, however, that the tracking device may also be placed at a distal or intervention end of the instrument68. Additional representative or alternative localization and tracking system is set forth in U.S. Pat. No. 5,983,126, entitled “Catheter Location System and Method,” issued Nov. 9, 1999, which is hereby incorporated by reference. The navigation system26may be a hybrid system that includes components from various tracking systems. According to various embodiments, the navigation system26can be used to track the instrument68relative to the patient30. The instrument68can be tracked with the tracking system, as discussed herein, such as by tracking and determining a pose of the tracking device66. Image data of the patient30, or an appropriate subject, can be used to assist the user72in guiding the instrument68. The image data, however, is registered to the patient30. The image data defines an image space that is registered to the patient space defined by the patient30. The registration can be performed as discussed herein, automatically, manually, or combinations thereof. Generally, registration allows a map, also referred to as a registration map, to be generated of the physical pose of the instrument68relative to the image space of the image data. The map allows the tracked pose of the instrument68to be displayed on the display device84relative to the image data108. It is understood that the display device84may be any appropriate display device, or include more than a single display device, such as including augmented reality viewers, head mounted displays, etc. A graphical representation68i, also referred to as an icon, can be used to illustrate the pose (e.g. three-dimensional coordinate location and one or more degree of freedom orientation) of the instrument68relative to the image108. With continuing reference toFIG.1and additional reference toFIG.2, a subject registration system or method can use the subject tracking device58. The tracking device58may include portions or members120that may be trackable, but may also act as or be operable as a fiducial assembly. The fiducial assembly120can include a clamp or other fixation portion124and the imageable fiducial body120. It is understood, however, that the members120may be separate from the tracking device58. The fixation portion124can be provided to fix any appropriate portion, such as a portion of the anatomy. As illustrated inFIG.1, the fiducial assembly120can be interconnected with a portion of a spine such as a spinous process of the subject30. The fixation portion124can be interconnected with the spinous process in any appropriate manner. For example, a pin or a screw can be driven into the spinous process. Alternatively, or in addition thereto, a clamp portion124can be provided to interconnect the spinous process. The fiducial portions120may be imaged with the imaging device80. It is understood, however, that various portions of the subject (such as a spinous process) may also be used as a fiducial portion. In various embodiments, when the fiducial portions120are imaged with the imaging device80, image data is generated that includes or identifies the fiducial portions120. The fiducial portions120can be identified in image data automatically (e.g. with a processor executing a program), manually (e.g. by selection an identification by the user72), or combinations thereof (e.g. by selection an identification by the user72of a seed point and segmentation by a processor executing a program). Methods of automatic imageable portion identification include those disclosed in U.S. Pat. No. 8,150,494 issued on Apr. 3, 2012, incorporated herein by reference. Manual identification can include selecting an element (e.g. pixel) or region in the image data wherein the imageable portion has been imaged. Regardless, the fiducial portions120identified in the image data can be used as fiducial points or positions that can be used to register the image data or the image space of the image data with patient space. In various embodiments, to register an image space or coordinate system to another space or coordinate system, such as a navigation space, the fiducial portions120that are identified in the image108may then be identified in the subject space defined by the subject30, in an appropriate manner. For example, the user72may move the instrument68relative to the subject30to touch the fiducial portions120, if the fiducial portions are attached to the subject30in the same position during the acquisition of the image data to generate the image108. It is understood that the fiducial portions120, as discussed above in various embodiments, may be attached to the subject30and/or may include anatomical portions of the subject30. Additionally, a tracking device may be incorporated into the fiducial portions120and they may be maintained with the subject30after the image is acquired. In this case, the registration or the identification of the fiducial portions120in a subject space may be made. Nevertheless, according to various embodiments, the user72may move the instrument68to touch the fiducial portions120. The tracking system, according to various embodiments, may track the pose of the instrument68due to the tracking device66attached thereto. This allows the user72to identify in the navigation space (which may include or be a portion of the subject space) the poses (including, for example, six degree of freedom information including locating and orientation) of the fiducial portions120that are identified in the image108. After identifying the positions of the fiducial portions120in the navigation space, the map may be made between the subject space defined by the subject30in a navigation space and the image space defined by the image108. Accordingly, identical or known locations allow for registration as discussed further herein. During registration, the map is determined between the image data coordinate system of the image data such as the image108and the patient space defined by the patient30. Once the registration occurs, the instrument68can be tracked with the tracking system that is registered to the image data to allow an identification and illustration of a pose of the tracked instrument68as an icon superimposed on the image data. Registration of the image108(or any selected image data) to the subject30may occur at any appropriate time. In various embodiments, the image space108and the subject space defined by the subject30may be registered according to a method150. As discussed above, the image to patient registration may include acquiring and/or accessing (e.g. from a memory system having the image data stored thereon) image data of a subject, such as the subject30, with fiducials in block152. The image data of the subject30may be any appropriate image data, such as image data acquired with the imaging system80. Further, the fiducials may include the fiducial portions120, as discussed above, and/or appropriate anatomical portions of the subject30. For example the fiducial portions may include portions of the anatomy such as the spinous process of the subject30. Nevertheless, the acquired image data may include the fiducials therein. Once the image data is acquired of the subject with the fiducials, identification of the fiducials in the image space may occur in block154. The identification of the fiducials in the image space in block154may occur, as also discussed above. For example, an automatic identification of the fiducials may be made in the image data that defines the image space, such as through automatic segmentation of the fiducial portions within the image. Also manual identification and/or combination manual-and-automatic identification may be used to determine the fiducials in the image space. The combination may include the user72identifying one or more pixels as seed pixels and a processor executing a segmentation program based on the seed pixels. The identification of the fiducials in a subject space and/or navigation space occurs in block156. The subject space may be coextensive with the navigation space and/or may overlap. Generally, the navigation space is the volume that may be tracked with the tracking system, such as the localizer94and may encompass all or a portion of the subject or patient30. The identification of the fiducials in the navigation space may occur in various manners such as moving a trackable instrument, such as the instrument68, relative to the fiducial portions120(which may also be a tracking device) and/or the spinous process. The tracking system of the navigation system26may track the instrument68and the navigation system26may include an input to input the portions that are the fiducial portions120in the navigation space. The determination or identification of the pose (e.g. including at selected degree of freedom information including three dimensional location and orientation) of the fiducials in the navigation space may then be used to form the map, between two or more coordinate systems, in block160. Determination of the map determined in block160may be a correlation or registration of the coordinate system of the image space to the coordinate system of the navigation space relative to and/or including the subject30. The map allows for a determined pose of a tracked portion in the navigation space to be mapped to an equivalent or identical pose in the image. Once the mapped pose is determined, the pose may be illustrated or displayed with the display relative to the image108, such as by the superimposing of the icon68ion or relative to the image108. The image to patient registration allows for the illustration of tracked instruments or items relative to the image108. Without the registration, however, any element not trackable or registered to the image108may not be appropriately or precisely illustrated at a real world pose relative to the image108. Thus, registration may allow for illustration, such as with the icon68i, of a determined pose of the instrument68relative to the subject30. After the registration of the image space to the patient space, the instrument68can be tracked relative to the image108. As illustrated inFIG.1, the icon68irepresenting a pose (which may include a 6 degree of freedom pose (including 3 dimensional location and 3 degree of freedom orientation)) of the instrument68can be displayed relative to the image108on the display84. Due to the registration of the image space to the patient space, the pose of the icon68irelative to the image108can substantially identify or mimic the pose of the instrument68relative to the patient30in the patient space. As discussed above, this can allow a navigated procedure to occur. With additional reference toFIGS.2and3, and continuing reference toFIG.1, the localizer94, which may also be referred to as an array or an antenna array, may be provided in any physical configuration for use of a selected or appropriate procedure. For example, as illustrated inFIG.1, the localizer94is provided or formed to include a selected geometry, such as lobes. In various embodiments the localizer94, as illustrated inFIG.3, may be planar or more elongated in shape. The localizer94may include a plurality of coils, such as any appropriate number, to generate the navigation field or domain. The navigation field or domain may include a volume180. The navigation volume180is generally sized or moved or placed relative to the subject30to allow for navigation of one or more instruments, such as the instrument68relative to the subject30. The instrument68may include one or more tracking devices, such as the tool tracking device66. The array94may transmit a signal, as discussed further herein, which may be received by the tracking device66or other appropriate tracking devices, such as the subject tracker58and/or the imaging device tracker62. In various embodiments, the array94may be incorporated into the bed or support104. Alternatively, or in addition thereto, the array94may be configured into a shape or size such that the array may be placed below the subject30and the subject30is placed atop at least a portion of the array94. In various embodiments, for example, the array94may be placed (e.g. fixed) near a lumbar spine of the subject30and/or a head of the subject30to allow for the navigation field180to be centered and/or encompass the selected area of the subject30for navigation. The navigation system26may be operated in selected environments, such as in an operating room that includes various other components in addition to the instrument68. For example, the navigation system26may operate in an operating room including the imaging system80, the operating table104, and/or other components. Further, a plurality of instruments may be provided for a selected procedure such as the instrument68and additional or alternative instruments such as a drill motor69that may be placed in a storage or holding area71. The holding area71may include a conductive and/or magnetic material, such as a metal tray or a conductive polymer tray. The tray71may be formed of various or selected metal or metal alloys, such as aluminum or stainless steel. In various embodiments, the signal transmitted by the array94may be interfered with due to interactions or distortions from various metallic substances, such as the tray71, the drill69, the imaging system80, or other metal portions in the operating room in which the navigation system26is placed. Objects or items that may distort the field or signal may be referred to as distorting or distortion objects. The array94may be operated, as discussed further herein, to emit a signal or field. The field emitted by the localizer94may be sensed by one or more of the tracking devices, such as the instrument tracking device66. The field emitted by the array94, therefore, may be distorted due to the metallic objects in or near the navigation volume180. Accordingly, the signal received by the tracking device66, or other tracking devices in the navigation system26, may include both the emitted signal and distortion. Distortion may be generated by eddy currents in conductive items or magnetizations in magnetic items, which may be referred to herein as “distorting items”. The signal received by the tracking device66may be transmitted to an appropriate processing system such as one or more processors in the controller110and/or the processing unit102. The signal received may include distortion, if objects are near the navigation volume180that cause distortion. Accordingly, a distortion detection and correction (DDC) module190(which may include an equalization) may be incorporated or executed by the processing unit102. The DDC module190, as discussed further herein, may be used to assist in removing distortion from the signal received by the tracking device66. Once the distortion is removed in the DDC module190, a navigation module198may also be incorporated into the processing unit102and/or executed by the processing unit102. The navigate module198navigates with the corrected signal to determine a pose of the tracking device66in the navigation volume180. Thus, a tracking signal may be emitted by the localizer and received by the tracking device66. The received tracking signal may include distortion. As discussed above, the navigation of the instrument68including in the tracking device66may allow for an illustration of a graphical representation68iof the instrument68relative to the image108of the subject30. Due to the navigation registration, therefore, the user72may view a pose of the instrument68relative to the subject30with the monitor84. It is understood, by one skilled in the art, that the tracking device66may also transmit a signal that is received by the localizer94. The transmitted signal may be received by the localizer94and a similar equalizer and navigation module may be used to determine a pose of the tracking device66relative to the subject30in a similar manner but where the signal is received by the localizer94, rather than transmitted by the localizer94. Further, one skilled in the art will understand that the plurality of instruments may be navigated substantially simultaneously to allow for illustration of a plurality of instruments relative to the image108simultaneously when a plurality of instruments are tracked relative to the subject30in the navigation volume180substantially simultaneously. The localizer94, regardless of its configuration or external geometry may include one or more coils200. The localizer may include an appropriate number of coils200, such as enough to transmit a signal to resolved at the tracking device66to navigate the tracking device66. The localizer94, therefore, may include one or more coils200, including nine or more coils, 12 or more coils200, or up to 36 coils, or an appropriate number of the coils200The coils200may be provided in any appropriate number and the number discussed herein is merely exemplary. For example, the localizer94may include three coils that are substantially orthogonally oriented and placed relative to one another around a single center or origin. Alternatively, or in addition thereto, one or more coils may be placed and oriented at a selected angle relative to one another within the localizer94. Regardless of the configuration, the one or more coils generate a navigation field with an electromagnetic (EM) signal that may be sensed by the respective tracking devices, including the tracking device66, to allow for determination of a pose of the tracking device66in space. With continuing reference toFIG.1and additional reference toFIG.3, the localizer94may be configured in any appropriate manner, including those discussed herein. Exemplary illustrated inFIG.3is a rectangular localizer assembly. The localizer assembly94may include one or more coils200, such as a first coil200a. The coil200amay be included in the localizer94along with one or more other coils, such as a second coil200b. It is understood that any appropriate number of coils may be provided and two coils200a,200bis merely exemplary. Further, the localizer94may be controlled by the controller110and/or have an onboard controller such as a controller or control module110′. Further, in various embodiments a local power source or converter may be provided at the localizer94. For example, a power converter or battery may be provided to provide power to the controller110′ and/or the coils200to transmit the tracking signal. In various embodiments, an external power source, as an alternative to and/or in addition to the local power source, may transmit power to the controller110,110′ and/or the coils200from a location away from the localizer94. Regardless of the number or configuration, the respective coils, including the coils200, may be driven to transmit a signal that may be received by the tracking device66. In various embodiments, for example, the respective coils200a,200bmay be placed or incorporated into an “H” bridge configuration or switch system. With reference to the coil200a, and understanding of the second coil200bmay be incorporated into a similar configuration, the coil200amay be interconnected between a drive source and a ground with a plurality of switches. In various embodiments, for example, the coil200amay be integrated into an “H” bridge assembly220. The “H” bridge assembly220may include a plurality of switches including a first switch222, a second switch224, a third switch226and a fourth switch228. The switches222-228may selectively allow a current to be driven through the coil200afrom a source or voltage source230to a ground or outlet234. For example, the first switch222and the second switch224may be closed to allow a voltage to form across the coil220aand a current to flow through the coil200ain a first direction. Similarly the third switch226and the fourth switch228may be closed, with the respective first and second switches222,224being open, to allow current to be driven through the coil200ain a second direction. As discussed above, the controller110may be used to control selected switches to pass a current through the coil200a. The currents pass through the coil200ato cause signals to be emitted by the coil200aand to be received by the tracking device66. Similarly an “H” bridge220bmay be connected to the coil200band operate in a similar manner. The controller110and/or control110′ may operate both of the “H” bridge assemblies220a,220bto power or transmit a signal through the respective coils200a,200b. It is understood that the “H” bridge assemblies may be provided in any appropriate manner such as with manual or physical switches, transistors switches, or any appropriate switches relative to the respective coils. Moreover, as discussed above, any appropriate number of coils may be provided with the localizer94to generate navigation field as selected to generate or provide the navigation volume180. The schematic or illustration ofFIG.3is merely exemplary for the current discussion. The coils, such as the coil200a, may be powered via the “H” bridge assembly220ato provide a signal for navigation of the instrument68. The “H” bridge assembly220amay be provided in the localizer94to allow the coil200ato be driven while maintaining a selected energy or field emission and heat generation of the coil200aand localizer94. The localizer94, therefore, may include an appropriate number of coils such as between 1 and 36 coils, including three coils to 15 coils, while still maintaining a selected field emission and heat generation. The plurality of coils may be driven with the controller110,110′ in an appropriate manner, as discussed herein, to generate the navigation domain180. The tracking system may include the localizer94, as discussed above. The localizer94may be controlled by a controller110. The localizer94may transmit a field or emit a field113that may be sensed by the tracking device66of the instrument68. It is understood that other appropriate tracking devices or receiving devices (e.g. the calibration receiver95) may also sense the field113of the localizer94. The field113may be generated in an appropriate manner, such as including or having a spread spectrum. The field113may also have, in addition or alternatively, a modulation that may be sensed by the tracking device66. The field113may assist in reducing or eliminating distortion or interference of the filed sensed by the tracking device66, as discussed further herein, due to an interfering, also referred to as a distorting or distortion, object. As discussed above the localizer94may be controlled by the controller110,110′ (discussion herein related to the controller110is intended to encompass all appropriate controllers, including those discussed above, and reference to only controller110is merely for ease of the current discussion), according to an appropriate transmission system. As discussed above, the coil, such as the coil200a(also discussion herein to the single coil200ais merely exemplary and for ease of the current discussion), may be powered or connected with the “H” bridge configuration220a. The “H” bridge configuration220may be provided in any appropriate manner including switches (e.g. physical or manual) and/or transistors that may be operated with the controller110. Regardless, the coil or plurality of coils of the localizer94may be operated to transmit with a binary transmission system or scheme including a binary near orthogonal (BNO) transmission system or scheme. The coil or plurality of coils of the localizer94may be operated to transmit signals as sets of binary near orthogonal (BNO) sequences for efficient recovery of both the transmitted signals and the impulse responses of the system and the impulse responses of distorters (also referred to as distortion items) in the navigation field. Under the BNO scheme, a pseudorandom binary (PRB) sequence, also referred to as a pseudo-noise (PN) sequence with one such type being a maximum length (ML) sequence, may be generated with the controller110to be transmitted by the localizer94as the tracking signal113. The tracking signal113transmission may be also be a spread spectrum transmission such that it is spread across a large or broad frequency spectrum or over a large or broad frequency spectrum which may also be segmented due to time. The PN sequence may be provided in a generally orthogonal or near orthogonal manner to provide an appropriate transmission for receiving by the tracking device66, or other appropriate tracking device. The tracking signal113may be used for navigation of the tracking device66. Further, discussion of the single tracking device66, or any appropriate or single portion of the navigation system26herein, is merely exemplary and intended for the ease of the current discussion unless specifically indicated otherwise. In various embodiments, therefore, cyclic shifts or offsets of the same repeating PN sequence are transmitted, one on each transmit coil. Statistically, an autocorrelation function of the PN sequence is equal to 1 at an offset zero and -12n-1 at all other offsets, where the sequence length equals 2n−1 and the number of sequence generator bits equals n with n=14 useable in various embodiments. Cyclic shifts or offsets of the PN sequence may be understood to be nearly orthogonal to one another in the sense that any pair of distinct shifts of the sequence are poorly correlated for any sufficiently-large value “n”. Systems which demodulate all cyclic shift amplitudes in the repeating PN frame may recover the associated coil signal amplitudes by multiplying by the inverse of the PN leakage matrix, which has 1 on the diagonals and -12n-1 elsewhere. In addition, when the PN offsets of the transmit coils have spacings greater than distorter response durations (i.e. a time of receiving a distortion from a distorting object), this method may recover the distorter impulse response to each generator coil. In various embodiments, an offset may be 10 sequence generator bits. Select methods may be used to perform the calculations, discussed above, including the Walsh-Hadamard transform via the fast-Walsh-transform based method as described “Impulse response measurements using MLS”, by Jens Hee, http://www.jenshee.dk/signalprocessing/mls.pdf (2003). The method may be used to directly perform both the demodulation (multiplication by the PN sequence at all offsets) and the leakage inversion. As discussed above, the controller110may power the coil200ato transmit a signal that may be received by the tracking device66. It is understood, as discussed above, that the tracking device66may also transmit a signal in a similar manner, as discussed herein, that is received by the one or more coils of the localizer94. The tracking device66may also include a plurality of coils, such as coils that are oriented substantially orthogonally to one another around a central point and/or separated from one another. In various examples, the tracking device66may include a plurality of coils, such as three coils66a,66b, and66c. The tracking device66, or any appropriate receiving coil device (e.g. the calibration receiver95), however, may include a selected number of coils For example, one coil, more than one coil, at least three coils, or more than three coils, such as six coils. The number of receiving coils may be appropriate to navigate the tracking device66. Each of the coils may be formed of a selected conductive material to have a current induced therein by the signal from the localizer. In various embodiments the coils may include wire wrapped around a center and/or traces formed on a printed circuit board (PCB). Nevertheless, the tracking device66, as discussed herein, may receive a signal from the localizer94although it is understood by one skilled in the art that the localizer may receive a signal from the tracking device and vice versa. In various embodiments, as discussed above, the controller100may cause or signal the one or more coils, such as the coil200a, of the localizer94to transmit a signal which may also be referred to as a tracking signal, as discussed herein. The coils200may be formed of a selected conductive material, such as a coil of metal or metal alloy wire. An impulse response(s) is(are) calculated from the received, continuously-transmitted BNO signal set from the transmit coils. The tracking signals are a set of BNO signals that include the same binary PN signal that is delayed by a different amount for each coil of the localizer. An inter-coil offset may include a selected time delay spacing is greater than the length of the metallic distorter impulse response length. The signal delay or spacing may include a selected duration, such as about 1 to 20 milliseconds, including 5 to 10 milliseconds, with an equivalent or greater spacing between signals from each coil. The tracking signal transmitted may be in any appropriate frequency range such as in a frequency range of about 5 hertz (Hz) to about 30 megahertz (MHz), further including about 10 Hz to about 3 MHz, and further including about 10 Hz to about 400 kilohertz (kHz). The signal may be transmitted at a selected frequency or over a range of frequencies in a spread spectrum fashion in the selected range. For example, a spread spectrum signal may transmit a signal across a spectrum of about 1 Hz to 30 MHz, including about 10 Hz to about 400 kHz that is transmitted at a sample rate at or about 375 kHz. In various embodiments, the control over the signal is the sample rate and waveform, which may include a binary drive waveform. The spectrum may be flat from the direct current (D.C.) to the sample rate. In various embodiments, therefore, the spectrum is flat when navigating the instrument, as discussed above. The controller via the H-bridge configuration may drive the coils, such as the coil200a, at the selected frequency or across a spread spectrum of frequency near the selected frequency. As discussed above, the localizer94may transmit a signal from the controller110through one or more of the coils, such as the coil200a. As further discussed above the H-bridge configuration220amay be provide in any appropriate configuration such as including transistors at the switches222-228. Accordingly, the controller100may cause the coil200ato transmit a signal (e.g. an electromagnetic signal) to be received by the tracking device66. The navigation system26, however, may transmit a magnetic signal using any appropriate manner, including but not limited to, H-bridge circuits and closed loop analog circuits. With reference toFIG.4AandFIG.4B, a transmit to receive calibration and/or equalization (C/E) procedure300and related schematic thereof is illustrated. As discussed herein, with reference toFIGS.5A and5BandFIGS.6A and6B, various additional and/or alternative C/E methods and systems may be used. In various embodiments, the C/E may include or be performed as a full system C/E and/or as various sub-channels or components. With initiate reference toFIGS.4A and4B, the C/E procedure300may be a full system C/E also referred to as an end-to-end C/E include various procedural steps such as starting in start block310. After starting in the start block310, a calibration or equalization signal may be generated from the controller110and sent to the localizer94(which may also be referred to as a transmitter) in block311, illustrated schematically as311′. The calibration signal may then be transmitted from the localizer94in block314, illustrated schematically as314′, to be received, such as at the calibration receiving coil95and/or other appropriate receiver, such as the tracking device66. Transmission of the calibration signal in block314may include transmitting a calibration signal according to the spread spectrum scheme, as discussed above. Further, the transmission may include the PN signal from the coil200aand the other coils200of the localizer94. As discussed above the signal sent by the coils may be generated as a PN sequence. The PN sequence may include selected lengths, such as a length of 1023 to 16383 in a sequence. The various coils may be off-set relative to one another by an appropriate number such as about 1023 length to achieve a distinction between the several coils200of the localizer94. The PN sequence may be generated and transmitted with the controller110. The transmitted signal at the selected frequency or spread spectrum, as discussed above, is to be respectively received by the tracking device66and/or other appropriate receiver, such as the calibration receiver95(even with reference to only one receiver coil herein). The coils200, therefore, may generate or transmit the signal in an appropriate time, such as in sequence or substantially simultaneously to be received by the tracking device66. The PN sequence may be generated according to any appropriate technique. In various embodiments, for example, a PN sequence may be generated with an irreducible polynomial. The tracking device66may receive the transmitted calibration signal and transmit the received signal to the controller110in block318, illustrated schematically as318′. The received calibration signal in block318may then be sampled and various calculations may be performed by the controller120(or any appropriate processor system) to perform a calibration in block322. The calibration in block322may include calibration based upon various parameters such as transmission distance, field strength at a known pose, or other appropriate calibration parameters. Calibration in block322can be performed according to appropriate techniques, as discussed below. In various embodiments, calibration in block322could include impulse response normalization via placing the tracking device66(e.g. including coils) at a fixed pose with respect to the localizer94including one or more of the coils200. Transmission calibration could include transmitted magnetic field measurements via an external or separate magnetometer and/or as previously characterized at the tracking device66(e.g. sensing coil). Receiver coil calibration could include received voltage measurement via external multimeter at or near the tracking device and/or as previously characterized with the tracking device66(e.g. sensing coil). The calibration in block322may include ensuring a known or clean room field strengths at selected poses. The calibration may include placing the localizer94at a selected location, which may also be referred to as an origin, and moving the tracking device66or an appropriate receiving tracking device at a plurality of known poses (i.e. locations and orientations) relative to the origin. The signal received by the tracking device66may then be used in the calibration322. For example, the calibration may include or account for possible distortion or noise in the signal as the signal starts and travels through transmitter (e.g. localizer94) circuitry and filters, transmitter coils, air, tracking device66coils, circuitry and filters related to or included with the tracking device66, and then as the signal is received back at the controller. The calibration, regardless how determined including as discussed above, may then be equalized in an equalization step in block324. In the equalization in block324an equalization is determined between each of the coils200of the localizer94and the tracking device66. Each transmit coil200and the tracking device66may be equalized for impulse response recovery and normalization of the signal. It is understood that discussion of the tracking device66may include discussion of a plurality of coils in the tracking device66, such as three coils, as discussed above. Accordingly, equalization may be between each of the coils200of the localizer94and each of the coils of the tracking device66. For example, between the coil200aand each of the coils66a,66b, and66c. Equalization includes removing distortion and/or accounting for noise of the system, including from the controller110and the various circuits of the localizer94and receiver66to allow recovery of a discreet time binary signal from an interference free system. Generally, the equalization is performed by removing distortions of the drive and reception hardware and is to leave only the signal and noise from any external distortion responses. In particular, a binary unitary magnitude pseudo-noise signal measured as a voltage at the receive coil of the tracking device66may be measured and an inverse thereof is computed. The equalization then convolves the determined inverse with the signal received at the tracking device66(i.e. coils in the tracking device66) to remove the effects of the localizer94and the tracking device66and the hardware associated therewith to leave the drive signal from the controller110and noise or external distortions in the field. The equalization is performed by determining coefficients. In particular, an algorithm may be used to determine the coefficients in a test or calibration equalization determination. Equalization may be performed in any appropriate manner, including those generally understood by one skilled in the art. For example, optimize and combine finite impulse response (FIR) and bidirectional infinite impulse response (IIR) filters may be used to equalize channels. The determined coefficients may be used to remove hardware distortion in the equalization between the localizer coil200and any coil of the tracking device66. Therefore, equalization block324may be used to generate or determine a signal that is without distortion due to the hardware of the localizer94transmitting via the coils200and being received at the tracking device66and the coils included therein. Thus, the equalized signal may be used to determine a pose of the tracking device in a field generated by the localizer94. As discussed above, the localizer94may transmit a signal according to BNO scheme where each coil200is offset from another coil by about 1023 bits in the PN sequence. In various embodiments, as briefly noted above, a selected sub-channel or sub-portion of the navigation system26may be calibrated and equalized. For example, with reference toFIGS.5A and5B, the respective sub-channels of/to each the transmitter or localizer94and/or the receiver or tracking device66may be individually calibrated and equalized. This may be in addition to and/or alternatively to calibrating and equalizing the entire system, and end, as discussed above and illustrated inFIGS.4A and4B. With initial reference toFIG.5A, a method300afor calibration and equalization is illustrated. The method300amay include portions similar to those discussed above in the method300, and like reference numerals will be used augmented with a lowercase “a”. Accordingly, the method300amay begin at block310a. The process300amay then move to block311ato generate a signal with the controller, such as the controller110. The signal that is generated may include the PN sequence, as discussed above. Therefore, generating the signal at the controller in block311ais similar to the generation of the signal in block311as discussed above. The generation of the signal and the controller311amay then be sent through and/or to various components of the navigation system26, including those as discussed above. The calibration signal may be sent to the localizer in block326, illustrated schematically as line326′. The signal may be sent to the various components from the controller110to the localizer94, including various circuitry and filters, the transmitter coils (e.g. coils200), and other components between the controller110and the localizer94and/or including the localizer94. The signal sent to the localizer94may then be transmitted back to the controller110, after having passed through all of the components of the localizer portion of the navigation system26. Therefore, the controller110may receive a signal returned from the localizer components, such as transmitted from the coils and/or return through a return line to the controller110, after having passed through all of the components of the localizer94portion. The controller110may also transmit a signal to the receiving coils, such as the tracking device66and/or the calibration receiver95(also referred to herein as the receiver). The signal transmitted to the receiver66may be substantially identical to the signal transmitted to the localizer94. Moreover, the signals may be transmitted substantially simultaneously and/or sequentially. Thus, the signal generated from the controller110may also be transmitted to the receiver66such as through all of the components thereof, including the receiver circuitry and/or filters, the sensor receive coils (e.g. of the tracking device66) including all of the selected or appropriate components thereof. The signal may then be returned to the controller110after having passed through all of the components such as the controller110receives the return signal from the receiver66. Accordingly, both of the blocks326and328may include two components including a transmission and return signal from the respective components including the localizer and the receiver. In other words, the signal may be sent from the controller110and return to the controller110for calibration and equalization. Accordingly, rather than only or requiring a signal to be transmitted to the localizer94which is then transmitted and received by the receiver66, and then transmitted back to the controller110, the signal may be sent and returned from each of the separate components as a separate sub-channel calibration and equalization. The return signals may then be further processed by the controller110or appropriate processor system, as discussed above. Calibration may occur in block322ain a manner similar to that discussed above. The calibration may include various calibration techniques or measurements, similar to those discussed above. For example, the calibration can include measurements of fields such as with a selected magnetometer and/or as previously characterized by the respective coils in the localizer94and/or the receiver66. The calibration signal and/or information may then be used for equalization in block324a. Again the equalization in block324amay include that as discussed above for equalization of the signal in the navigation system26. Accordingly, calibration and equalization of the navigation system26may include separate or sub-channel calibration and equalization portions and/or steps as discussed above and as exemplary illustrated inFIGS.5A and5B. A further and/or alterative sub-channel calibration and equalization may include the method as illustrated inFIGS.6A and6B. Initially, a method300bmay include steps or portions that are similar to the method300and the method300a, as discussed above. Like portions will be referenced with like numerals augmented with a “b”. Accordingly the method300bmay begin in start block310band include generation of a signal at a controller in block311b. Generation of the signal at the controller may be similar or identical to the generation of the signal at the controller100as discussed above. The signal may be a PN sequence and may then be transmitted or sent to various components of the navigation system26. For example, the signal may be sent to the localizer94through the various components of the localizer system including the circuits, filters, transmitter coils, and the like. The sending of the signal to the localizer94in block326band the return of the signal to the controller may be similar to that as discussed above in block326. The signal sent to the localizer94may be sent through the various circuitry of the localizer from the controller110to the localizer94. The return signal, that is returned to the controller110for various calibration and equalization, as discussed above and further herein, may be returned in various selected manners. As discussed above the signal may be sent or returned to the controller through a various return path from the localizer94to the controller110. In addition or alternatively, various external components may receive the transmitted signal from the localizer94, such as a magnetometer or the like and the signal from the external components may be returned to the controller. The signal, however, need not be wirelessly transmitted. The signal after having been passed through the various components, such as the circuitry, filter, and coils of the localizer94, may have a signal that is then returned to the controller110. Further, the generated signal may be transmitted to various circuitry and components of the receive66channel, as illustrated inFIG.6B. For example, receive coil circuitry66′/95′ may include various circuitry, cables, filters, and the like that are associated with the tracking device66and/or the calibration coil95. The receive coil circuitry66′/95′ may include various hardware or components that are generally understood to be fixed with the navigation system26. For example, as discussed above, the controller110may be connected to various tracking devices and/or receive tracking device information from various selected tracking devices, such as the tracking device66. In addition and/or alternatively thereto, the various other tracking devices, such as the tracking device62may also be connected to the controller110. During a selected procedure, for example, the tracking device coils or components66,95may be interchangeably with the receiver electronics66′/95′ and, therefore, connected to the controller110. Further, as is understood by one skilled in the art, during a selected procedure or a plurality of procedures, more than one instruments may be individually and separately tracked. Therefore, a plurality of the tracking device66may be individually and separately tracked. At a selected time, therefore, the identity of the selected and attached tracking device66may be input. The system, such as the controller110, therefore, may recall from a storage system the characterization of the selected and input tracking device66. Accordingly the sub-component calibration and equalization of the receiving circuitry66′/95′, may allow for calibration of the navigation system26separate from the individual components that are tracked therein, such as with the tracking device66. In light of the above, the generated signal from block311bmay be transmitted to the receive circuitry in block330. The signal received from the receive circuitry66′/95′ may be received in any appropriate manner, such as in a return signal and/or received from external components including a voltage measurement from an external multimeter, or other appropriate sensors. The calibration and equalization of the navigation system26, therefore, may also include, therefore, recalling a characterization of a selected receiver, also referred to as a receiver coil or component. For example, as discussed above, various components may be interconnected with the navigation system26for navigation of the selected components. Accordingly, the navigation system26may be calibrated and equalized without the specific and selected tracking device66. During a selected time, such as during a procedure, when the specific tracking device is selected, the identity of the selected tracking device may be input (e.g. manually by the user72, automatically by sensing or receiving a signal from the tracking device, or other appropriate mechanism). The navigation system26may recall the previously made and predetermined characterization (including equalization) of the selected tracking device. The characterization of the tracking device, therefore, may have been completed at any prior time. The characterization may include calibration and equalization information may that is previously determined and stored in a selected memory, such as in a database and/or in the memory of the navigation system26including the workstation98or processor system98. The prior determined characterization may be recalled, such as manually and/or automatically and/or combinations thereof, for completing a calibration and an equalization of the entire navigation system26including the selected specific receive coil66/95. Accordingly, when the selected receiver is selected the recalled characterization may be incorporated and/or used with the received signal from the received circuitry in block330and the received signal from the localizer in block326bto allow for calibration and equalization. Thus, with the recalled characterization from block322, calibration may proceed in block322b. After calibration in block322bequalization may occur in block324b. Calibration and equalization may include such a procedure, as discussed above. Accordingly, calibration and equalization of the navigation system26may occur in an appropriate manner, including those discussed above such as described and illustrated in theFIGS.4A-6B. It is understood that a calibration and equalization of the navigation system26may occur in any appropriate manner and may include any one of the above described systems or methods and/or combinations thereof. For example, an end to end complete calibration and equalization may occur according to the method300. Further, during a selected procedure, the calibration method300bmay be used to augment and/or update a calibration equalization of the navigation system26when the tracking device is added and/or changed during a selected procedure and/or between procedures. Accordingly, it is understood that the calibration and equalization may occur in any appropriate manner and need not be limited to only a single one of the methods as discussed above, but may include a plurality and/or combination thereof, such as an end to end calibration and equalization according to the method300that may be supplemented and/or redone according to the sub-channel procedures according to either and/or both of the method300aand300b. According to various embodiments, including those discussed above, the signal received at the tracking device66may be equalized with the equalizer190in step324according to the equalization process discussed above. With reference toFIG.7, a non-equalized impulse response may include a causal portion340and anti-causal portion344. The anti-causal portion may be used to compensate for various components of the navigation system26and may vary in light thereof. Accordingly, various different components may be used in the navigation system26and allow or cause the causal portion340to vary. The causal portion340may be used to compensate for variation and phase in the system's pass band and also in various components of the circuitry of the localizer94. The equalized signal in block324, therefore, may use the pre-equalization impulse response as illustrated inFIG.7to calibrate and equalize the signal. The localizer94may transmit a signal to generate an electromagnetic field. The signal may be a spread spectrum signal that is transmitted with a BNO scheme. The signal, including the BNO scheme, may be referred to as a tracking signal that includes an binary signal. The binary signal may be measured at the tracking device66that relates to the transmitted signal. The received signal may include various components, as discussed further herein, due to various distortions as discussed above and also herein. The equalization may assist in ensuring the recovery of the impulse response transmitted by the localizer94. Turning reference toFIG.8andFIG.9, a pre-equalized signal is illustrated inFIG.8as received by the tracking device66. The pre-equalized signal inFIG.8illustrates different received signals due to system distortions and including distortion causing materials in the field or near the path of the tracking device66. For example, graph line350relates to a value over time of the pre-equalized signal received by the tracking device66with no distorting item. A second graph line354illustrates the received signal over time when a portion of aluminum is placed or located near or causes distortion in the received signal. A third graph line358illustrates the received signal when a selected steel material is located near the tracking device66. As illustrated inFIG.8, by the graph lines350-358, the signal received by the tracking device66may vary depending upon material located near the tracking device66and/or that would distort the signal transmitted by the localizer94. As discussed further herein, the distortion caused by selected materials may be removed by analyzing the received signal to determine whether distortion is present and, if present remove the same. As discussed herein, distortion, whether present or not, may be determined. If distortion is determined to be present, it may be removed to allow recovery of an undistorted tracking signal including the impulse response. With reference toFIG.9, a method or process of navigation370is illustrated. The navigation process can begin at start block374and include transmitting a signal or signals in block378. As discussed above the signal as transmitted may include the spread spectrum signal according to the BNO scheme, discussed above. The signal transmitted by the localizer94may be transmitted into the navigation volume180. As discussed above, the transmitted signal may generate near field magnetic fields with wavelengths greater than or equal to 10 meters. The navigation volume180may be dependent upon various factors such as the size of the coil200, the overall size of the localizer94, power transmission, and other factors. Nevertheless the navigation volume180may be a volume of about 0.001 m3to about 1 m3, including about 0.01 m3to about 0.5 m3. The transmitted signal or signals may be received by the tracking device66in block382. The received signal in block382may be received by the tracking device66and/or transmitted to the navigation processor102. It is understood that the method or process370may be executed by the processor102with a transmit signal378may be a signal to the localizer94to transmit a signal and may receive signal in block382may be the signal received and transmitted to the navigation processor102from the tracking device66. The method370may include a transmission of the signal by the localizer94and receiving the signal by the tracking device66, or vice versa, and the navigation processor102may execute instructions to make a determination of the navigation in the method370. After the signal or signals is received in block382, a signal may be processed, such as demultiplexed and equalized, in block386. As discussed above, the received signal is received with the BNO scheme and therefore each cyclically shifted or offset code, corresponding to each transmit coil, may be demultiplexed from the received signal for further analysis. Equalization in block386may be similar to the equalization block324, as discussed above. Generally, as discussed above, the localizer94may include the coil200aand the tracking device66may include the coil66a. It is understood that discussion herein to the coil66amay include or be similar to the discussion of a plurality of coils at the tracking device66and discussion of the single coils66aherein is merely exemplary. The equalization between the coil66aand the coil200amay allow for the impulse response recovery of the transmitted signal. After equalizing the signal in block386, as discussed above such as with the equalizer190, the equalized signal may be evaluated to allow for a determination in block390of whether distortion is present. The determination of whether distortion is present may be made based upon the received signal, for example as illustrated inFIG.10. The received signal, as illustrated inFIG.10, may include a determination or evaluation of an initial impulse as illustrated by a black dot394in the graph ofFIG.10. The impulse response may be the equalized impulse response from the received signal as equalized in block386. The impulse response may further include a residual or tail that is a non-impulse or distortion portion that may include one or more tail signals or points398. The tail points398may include a plurality of tail points in a tail portion402. The tail portion402, or a presence of a tail portion, may be used to determine whether distortion is present. Accordingly, if the signal, that includes an impulse response as illustrated inFIG.10, as graphed over time, includes substantially no tail, a determination that no distortion is made, and a no-distortion path410is followed. Calibration and equalization, as discussed above according to one or more of the various methods, may include a characterization of the system including a noise floor and a distortion limit. No presence of tails, i.e. distortion, may be defined as within these previously determined limits. If no distortion is found in the received signal after the equalization, such as determining that the tail402is not present in the signal, and the No distortion path410is followed, then a navigation of the tracking device66may be performed without correcting for a distortion. As discussed above, distortion may be present or found in the received signal due to various distorting items in the signal path, such as effecting the signal transmitted by the localizer94. Distortion may be caused by various items such as items in or near the navigation system26, as discussed above including the imaging device80, the instrument68, the operating or patient support table104, or other items. Further, distortion may occur due to other items actively transmitting a field, such as an electrical field from an electrically powered drill, other coils in the localizer94other than the pair being resolved or evaluated at a time, or other items. The equalization may be made on a pairwise (e.g. single coil200aof the localizer94and single coil66aand the tracking device66) basis. Accordingly, a determined pose of the tracking device66may be made by determining a pose of each of the coils66a-66cand the tracking device66for each of the coils200a-200nof the localizer94. It is understood, however, that tracking of the instrument68with the tracking device66may include navigation between a selecting number of coils of the localizer and the tracking device66. Thus, for example, navigation may occur with one tracking device and using nine or twelve transmit coils in the localizer94. Other examples may include combinations of one receive coil using five transmit coils to three receive coils using three transmit coils to twelve receive coils using one transmit coil. After determining there is no distortion, an evaluation of whether certain metrics are accepted may be made in block414. Metrics may include signal metrics, or any other appropriate metrics. Further predetermined acceptable ranges or thresholds for the metrics may be made and saved to be accessed by the navigation processor102. In various examples, predetermined signal strength values that are above or below a threshold may be determined. Thus, if a signal received is above a threshold it may be determined that a tracking device is too near the localizer and if a signal received is below a threshold the tracking device may be too far from the localizer. The threshold, however, may relate to localizer size and/or power, tracking device configuration, etc. Accordingly the metrics may be analyzed and determined in block414. If it is determined that the metrics are not acceptable in block414, a return or loop path418may be followed to transmit the signal in block378and/or to the receive signal again in block382. In various embodiments, the transmission may repeat automatically, thus looping to transmission may not be necessary or desirable and looping to receiving in block382may be appropriate. By receiving the signal again at the tracking device66, the signal may be reanalyzed. The transmitted signal may be transmitted over a selected span of time such as milliseconds, including a sequence of 1 to 100 milliseconds including about 30 milliseconds that may or may not be followed by a break or pause in a transmission. Therefore, the determination of whether the metrics are acceptable in block414, if not found to be acceptable, may allow for receiving a signal again in block382but not distributing navigation of the navigation system26in a time acceptable by the user72. However, if the metrics are not found to be acceptable over a reasonable period of time, such as about 30 to 500 milliseconds, the navigation system26may provide an output, such as with the display device84that may identify to the user72that an error has occurred and must be resolved. If the metrics are acceptable in block414a YES or solve path422may be followed. The solve path422may lead to a navigation solve or pose determination in block428. The navigation solve in block428may allow for illustration of the representation68ion the display device relative to the image data108on the display device84. The navigation solve allows for illustration and/or determination of a pose of the tracking device66relative to the subject30. Thus, navigation may occur of the instrument68relative to the subject30. With continuing reference toFIG.9, the navigation method370may also follow a distortion determined or distortion found path440, if distortion is found to be present in block390. The Yes distortion path440may lead to or enter a distortion correction, also referred to as remove, subroutine460. The subroutine460may include various procedures or processes to identify and correct for selected distortion, as discussed herein. In the subroutine, it is understood by one skilled in the art, that the herein described processes may be carried out sequentially and/or simultaneously, as discussed herein. Accordingly, whileFIG.9illustrates that the subroutine in a selected order, the processes in the subroutine460may occur substantially simultaneously. The cause of distortion may be any cause of distortion, including those discussed above. For example, a metal object that is conductive may be in the path of the field generated by the localizer94. For example, as illustrated inFIG.1, an aluminum object, such as the tray71that may be formed therefrom, may be in the path of the signal from the localizer94to the tracking device66. The aluminum tray71may cause the tail402, as illustrated inFIG.10. The tail402may include a plurality of response data points separated by time as illustrated along the x-axis inFIG.10. As exemplary illustrated inFIG.10the time may be separated by increments of microseconds but may also be any appropriate time segmentation. Nevertheless, the determination and identification of the tail402may be used to ensure or determine an appropriate magnitude of the initial impulse394. Generally, the initial impulse394occurs at a time “zero” when receiving the signal in block382. In particular, the signal is transmitted in block378and received in block382and the receiving of the signal in block382would be time zero which is also understood to be the start of the PN code or signal or shifts of the PN code. Any trailing or residual signal received signal thereafter may be caused due to distortion or a distorting object within the field along the signal path, such as the tray71. Thus, the initial impulse394may be distorted, such as in magnitude, and this distortion noted by the distortion tail402. With continuing reference toFIG.10the initial impulse394, may be illustrated on a graph for ease of discussion and calculation, as discussed herein. The initial impulse394is illustrated at zero time response to exemplary illustrate the initial impulse at time zero on the X-axis. Further, the initial impulse is shown at zero magnitude to better illustrate the value of the residual or tail response received in block382if distortion is present. The corrected or non-distorted dimension of the initial impulse394may be determined by calculating the tail402into the initial impulse394. The initial impulse and the tail may generally be a causal response where the tail402may be used to determine the expected or un-distorted impulse magnitude. The distortion present path440may first go to a residual or tail separation in block444. The residual separation may include a determination of all of the tail portion. As discussed above, the initial impulse at time zero may be determined such as based upon a determined or selected amount of time between the transmit signal and the received signal in block378,382respectively. For example, it may be determined that the time between the transmitting of the signal from the localizer94and the receiving of the signal at the tracking device66may be much less than microseconds. Accordingly, the navigation system26may determine that a received signal at the selected amount of time after transmission of the signal in block378, may be a zero time and the initial impulse. Any recovered impulse response thereafter may be determined to be the tail402. The determination of the tail402, however, may be in any appropriate manner, such as any recovered signal after the identified initial impulse. Regardless, the tail402, that may be determined or detected in block390when determining whether a distortion is present, may be separated from the initial impulse or first impulse394. The separation of the residuals provides separation of the tail dimensions or magnitude for further reconstruction. After separation of the tail in block444, a reconstruction may be performed in block448. The reconstruction block448may include reconstruction the distortion impulse response. As discussed above, the initial or zero time impulse394may be distorted and this distortion may be determined by the tail402, if present. Accordingly, once the tail is separated in block444the separated tail may be reconstructed into the distortion initial impulse to determine an actual or corrected impulse. The reconstruction may be in any appropriate type of reconstruction. For example a direct reconstruction may include an addition or additive reconstruction by adding the values of the tail402for a selected amount of time, such as about 1 to 10 milliseconds including 5 milliseconds, to the value of the distortion initial or zero time impulse. The direct reconstruction may allow for a fast reconstruction of the distortion impulse and may be appropriate for selected materials, such as conductive materials such as certain plastics or polymers, metal alloys or the like. Reconstruction may also include a modeled reconstruction of the impulse response that may be based upon weighting certain portions of the tail, adding or eliminating certain portions of the tail402, or other appropriate modeling techniques. In various embodiments, the reconstruction may not include first removing the tail in block444, but may include simultaneous separation and modeling. IN various embodiments, the tail may be summed and added to the impulse, particularly for conductive distortion materials. In other words, as a function of the residuals in a direct calculation summing the residuals to determine the distortion initial impulse. In a modeled or indirect calculation, the tail may be decomposed into separate functions and then fit for determining the distortion effect. For example, the decomposed functions may be fit to pre-determined or measured distorting materials or items. In other words, residuals may be modeled with a combination of parameterized impulse responses having conductive and conductive and magnetic contributions and/or with a combination of measured impulse responses including expected conductive and conductive and magnetic contributions. The reconstruction may be made in block448to determine the corrected or undistorted impulse response in block454. Following the reconstruction of the distortion impulse response in block448, a removal or deconvolution of the impulse response is made in block454. The removal or deconvolution of the impulse response in block454may include separating the distortion impulse response from the full impulse response via removal or deconvolution to determine the corrected or undistorted impulse response and impulse. Following the removal or deconvolution in block454, the navigation method370may then enter the determination of whether selected metrics are acceptable in block414. Similar to that discussed above, the determination of whether the metrics are acceptable in block414may allow for receiving an additional signal in the loop path418and/or navigation solving in block428. Accordingly, the method370may follow a no distortion path410and/or a distortion path440to solve a navigation and determine the pose of the tracking device66in space relative to the subject30. The method370may include the no-distortion path410and the distortion path440, the distortion path may include the distortion correction subroutine460. The distortion correction subroutine460may be executed by the controller110or navigation processor102to allow for removal or correction of the distortion from a distorting object to determine a true or correct pose of the tracking device66. The distortion may be detected in block390and removed in the distortion correction subroutine460as discussed above. As briefly discussed above, the subroutine460may be substantially sequential as discussed above. Thus, the various calculations may be processed, such as with a processor executed instructions, in the order as discussed above and illustrated directly inFIG.9. In various embodiments, however, all of the processes in the subroutine460may occur simultaneously or selected plurality of the processes may occur simultaneously. In other words, the subroutine460may occur via concurrent separation444, reconstruction448, and removal or deconvolution454. The subroutine460may, however, still follow the decision of wherein the recovered impulse response includes a distortion tail in block390. Then, the subroutine460may include simultaneous separation and deconvolution of reconstructed distortion impulse responses from the recovered impulse response to find a corrected impulse response and impulse. The corrected impulse response and impulse may be determined with a fit of the residuals to a combination of measured or modeled impulse responses including expected conductive and conductive and magnetic contributions. Accordingly, the navigation system26, as discussed above, may be used to determine a pose of the tracking device66that is associated, such as connected to, the instrument68. The navigation system26may therefore track the tracking device66and navigate the instrument68such as by illustrating the instrument68as the representation68ion the display device84. The use of the spread spectrum transmission may allow for a low power and high fidelity signal transmission with select electronics, such as the “H” bridge configuration discussed above. Further a selected scheme, such as the BNO scheme, may allow for transmission of a signal based substantially free of distortion or confusion with extraneous signals relative to the tracking device66. Further the received signal may be analyzed or reconstructed to determine is distortion is present or has been caused by distorting object and, if present, may be removed. Thus the pose of the tracking device66may be determined with a selected preciseness and correctness due to the received signal at the tracking device66. The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the invention, and all such modifications are intended to be included within the scope of the invention. It should be understood that various aspects disclosed herein may be combined in different combinations than the combinations specifically presented in the description and accompanying drawings. It should also be understood that, depending on the example, certain acts or events of any of the processes or methods described herein may be performed in a different sequence, may be added, merged, or left out altogether (e.g., all described acts or events may not be necessary to carry out the techniques). In addition, while certain aspects of this disclosure are described as being performed by a single module or unit for purposes of clarity, it should be understood that the techniques of this disclosure may be performed by a combination of units or modules associated with, for example, a medical device. In one or more examples, the described techniques may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit. Computer-readable media may include non-transitory computer-readable media, which corresponds to a tangible medium such as data storage media (e.g., RAM, ROM, EEPROM, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer). Instructions may be executed by one or more processors, such as one or more digital signal processors (DSPs), general purpose microprocessors, graphic processing units (GPUs), application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry. Accordingly, the term “processor” as used herein may refer to any of the foregoing structure or any other physical structure suitable for implementation of the described techniques. Also, the techniques could be fully implemented in one or more circuits or logic elements.

11857268

DETAILED DESCRIPTION The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the present invention are shown. The present invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided as teaching examples of the invention. Generally, FBGs may be integrated into OSS devices for force sensing. That is, FBGs can be used to measure axial strain in an optical fiber, where axial strain is a measure of temperature changes and axial force. When temperature is decoupled from the measurement, axial strain can be used to determine the axial force applied to the optical fiber; or if multiple FBGs are located along the length of an optical fiber, the shape of the optical fiber may be determined. At positions between FBGs or beyond the tip of the optical fiber, the shape can be estimated, projected, averaged, or the like. In multicore optical fiber with FBGs along the entire length of the optical fiber, signal losses at the distal tip of the optical fiber can obscure the FBG signals, diminishing shape sensing quality at the distal tip. A termination piece that is bound to a multicore optical fiber improves signal quality at the distal tip of the multicore optical fiber, thereby permitting shape sensing to be performed all the way to the distal tip of the multicore optical fiber. The term “shape sensing” used herein includes estimation, projection, and averaging of shape beyond the optical fiber, particularly with regard to projecting shape to a distal tip of the termination piece. The shape of the termination piece, or the remainder of the distal OSS device (the end of which may substantially correspond to the distal tip of the termination piece), may be determined in various ways, such as projecting the shape in a straight line from the distal tip of the multicore optical fiber to the distal tip of the termination piece. The termination piece may be broken by sufficient forces applied to the distal tip, in which case shape sensing to the distal end of the corresponding OSS device cannot be done simultaneously with measuring applied axial forces. Therefore, according to various embodiments, force sensing is enabled using a multicore optical fiber (e.g., of a guidewire or other OSS device) and a termination piece attached thereto, without breaking the termination piece while being able to shape sense all the way to the tip of the termination piece or the OSS device. Also, flexibility sufficient to navigate the OSS device through small spaces or passages is maintained. According to a representative embodiment, an OSS device includes an elongated outer body comprising flexible tubing configured to maneuver through a passage; an optical fiber extending through the elongated outer body, and enabling shape sensing by tracking deformation of the optical fiber along a length of the optical fiber; a termination piece attached to a distal tip of the optical fiber, the termination piece comprising a distal tip; and a force sensing region integrated with the elongated outer body and configured to sense an axial force exerted on a distal end of the elongated outer body via changes in axial strain on the optical fiber. The shape sensing occurs along the optical fiber to the distal tip of the termination piece. It should be understood that the disclosure is provided in terms of medical instruments; however, the present teachings are much broader and are applicable to any imaging instruments and imaging modalities. In some embodiments, the present principles are employed in tracking or analyzing complex biological or mechanical systems. In particular, the present principles are applicable to internal tracking procedures of biological systems and procedures in all areas of the body such as the lungs, gastro-intestinal tract, excretory organs, blood vessels, etc. The elements depicted in the figures may be implemented in various combinations of hardware and software and provide functions which may be combined in a single element or multiple elements. It should be further understood that the terminology used herein is for purposes of describing particular embodiments only, and is not intended to be limiting. Any defined terms are in addition to the technical and scientific meanings of the defined terms as commonly understood and accepted in the technical field of the present teachings. As used in the specification and appended claims, the terms “a”, “an” and “the” include both singular and plural referents, unless the context clearly dictates otherwise. Thus, for example, “a device” includes one device and plural devices. The statement that two or more parts or components are “coupled” shall mean that the parts are joined or operate together either directly or indirectly, i.e., through one or more intermediate parts or components, so long as a link occurs. Directional terms/phrases and relative terms/phrases may be used to describe the various elements' relationships to one another, as illustrated in the accompanying drawings. These terms/phrases are intended to encompass different orientations of the device and/or elements in addition to the orientation depicted in the drawings. A “computer-readable storage medium” encompasses any tangible storage medium which may store instructions which are executable by a processor of a computing device. The computer-readable storage medium may be referred to as a non-transitory computer-readable storage medium, to distinguish from transitory media such as transitory propagating signals. The computer-readable storage medium may also be referred to as a tangible computer-readable medium. In some embodiments, a computer-readable storage medium may also be able to store data which is able to be accessed by the processor of the computing device. Examples of computer-readable storage media include, but are not limited to: a floppy disk, a magnetic hard disk drive, a solid state hard disk, flash memory, a USB thumb drive, Random Access Memory (RAM), Read Only Memory (ROM), an optical disk, a magneto-optical disk, and the register file of the processor. Examples of optical disks include Compact Disks (CD) and Digital Versatile Disks (DVD), for example CD-ROM, CD-RW, CD-R, DVD-ROM, DVD-RW, or DVD-R disks. The term computer readable-storage medium also refers to various types of recording media capable of being accessed by the computer device via a network or communication link. For example, data may be retrieved over a modem, over the internet, or over a local area network. References to a computer-readable storage medium should be interpreted as possibly being multiple computer-readable storage mediums. Various executable components of a program or programs may be stored in different locations. The computer-readable storage medium may for instance be multiple computer-readable storage medium within the same computer system. The computer-readable storage medium may also be computer-readable storage medium distributed amongst multiple computer systems or computing devices. “Memory” is an example of a computer-readable storage medium. Computer memory is any memory which is directly accessible to a processor. Examples of computer memory include, but are not limited to RAM memory, registers, and register files. References to “computer memory” or “memory” should be interpreted as possibly being multiple memories. The memory may for instance be multiple memories within the same computer system. The memory may also be multiple memories distributed amongst multiple computer systems or computing devices. Computer storage is any non-volatile computer-readable storage medium. Examples of computer storage include, but are not limited to: a hard disk drive, a USB thumb drive, a floppy drive, a smart card, a DVD, a CD-ROM, and a solid state hard drive. In some embodiments computer storage may also be computer memory or vice versa. References to “computer storage” or “storage” should be interpreted as possibly including multiple storage devices or components. For instance, the storage may include multiple storage devices within the same computer system or computing device. The storage may also include multiple storages distributed amongst multiple computer systems or computing devices. A “processor” as used herein encompasses an electronic component which is able to execute a program or machine executable instruction. References to the computing device comprising “a processor” should be interpreted as possibly containing more than one processor or processing core. The processor may for instance be a multi-core processor. A processor may also refer to a collection of processors within a single computer system or distributed amongst multiple computer systems. The term computing device should also be interpreted to possibly refer to a collection or network of computing devices each comprising a processor or processors. Many programs have instructions performed by multiple processors that may be within the same computing device or which may even be distributed across multiple computing devices. A “processing unit” as used herein encompasses one or more processors, computers, application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or combinations thereof, using software, firmware, hard-wired logic circuits, or combinations thereof. That is, a processing unit may be constructed of any combination of hardware, firmware or software architectures, and may include its own memory (e.g., nonvolatile memory), computer-readable storage medium and/or computer storage for storing executable software/firmware executable code and/or data that allows it to perform the various functions. In an embodiment, processing unit may include a central processing unit (CPU), for example, executing an operating system. A “user interface” or “user input device” as used herein is an interface which allows a user or operator to interact with a computer or processing unit (computer system). A user interface may provide information or data to the operator and/or receive information or data from the operator. A user interface may enable input from an operator to be received by the computer and may provide output to the user from the computer. In other words, the user interface may allow an operator to control or manipulate a computer system and the interface may allow the computer system indicate the effects of the user's control or manipulation. The display of data or information on a display or a graphical user interface is an example of providing information to an operator. The receiving of data through a touch screen, keyboard, mouse, trackball, touchpad, pointing stick, graphics tablet, joystick, gamepad, webcam, headset, gear sticks, steering wheel, wired glove, wireless remote control, and accelerometer are all examples of user interface components which enable the receiving of information or data from a user. A “hardware interface” encompasses an interface which enables the processor of a computer system to interact with and/or control an external computing device and/or apparatus. A hardware interface may allow a processor to send control signals or instructions to an external computing device and/or apparatus. A hardware interface may also enable a processor to exchange data with an external computing device and/or apparatus. Examples of a hardware interface include, but are not limited to: a universal serial bus, IEEE 1394 port, parallel port, IEEE 1284 port, serial port, RS-232 port, IEEE-488 port, Bluetooth connection, Wireless local area network connection, TCP/IP connection, Ethernet connection, control voltage interface, MIDI interface, analog input interface, and digital input interface. A “display” or “display device” or “display unit” as used herein encompasses an output device or a user interface adapted for displaying images or data, e.g., from a computer system. A display may output visual, audio, and or tactile data. Examples of a display include, but are not limited to: a computer monitor, a television screen, a touch screen, tactile electronic display, Braille screen, Cathode ray tube (CRT), Storage tube, Bistable display, Electronic paper, Vector display, Flat panel display, Vacuum fluorescent display (VF), Light-emitting diode (LED) displays, Electroluminescent display (ELD), Plasma display panels (PDP), Liquid crystal display (LCD), Organic light-emitting diode displays (OLED), a projector, and Head-mounted display. Multiple, illustrative embodiments of an OSS device which integrates optical fiber and a termination piece into a structure that enables force sensing via changes in axial strain. The embodiments are intended to be illustrative, and not exhaustive, such that the additional related configurations may be included. In all of the embodiments, the termination piece of the optical fiber is protected from axial forces being applied directly to a tip of the termination piece. As discussed above, direct axial force on the termination piece can cause the termination piece or the multicore optical fiber to break, and thereby prevent shape sensing of the OSS device all the way to the distal end. Throughout the disclosure, like numbered elements in these figures are either equivalent elements or perform the same function. Elements which have been discussed previously will not necessarily be discussed in later figures if the function is equivalent. FIG.1is a simplified cross-sectional diagram of an optical shape sensing device including a force sensing region, according to a representative embodiment. Referring toFIG.1, optical shape sensing device100is an elongated, primarily flexible device configured for navigation through narrow passages, although rigid portion(s) may be included for purposes of measuring axial force Fz, as discussed below. For example, the optical shape sensing device100may be configured as a shape-sensed guidewire or catheter used for navigation through vasculature of a patient during interventional medical procedures, although other configurations and/or uses may be incorporated without departing from the scope of the present teachings. In the depicted embodiment, the optical shape sensing device100includes an elongated outer body110, which includes flexible tubing, e.g., to enable maneuvering of the optical shape sensing device100through a passage, as discussed above. The optical shape sensing device100also includes a multicore optical fiber120extending longitudinally through the elongated outer body110, and a termination piece130attached to a distal tip124of the multicore optical fiber120. The termination piece130includes a distal tip135, which may substantially coincide with a distal end115of the elongated outer body110(as well as the distal end of the optical shape sensing device100). Since the termination piece130is bound to the mutlicore optical fiber120, shape sensing is enabled by the optical shape sensing device100along the length of the multicore optical fiber120and to the distal tip135of the termination piece130. As discussed above, this means that optical fiber shape sensing is performed to the distal tip124of the multicore optical fiber120and projected to the distal tip135of the termination piece130(collectively referred to as shape sensing). A typical conventional optical shape sensing device differs in that, without a termination piece, good shape sensing data cannot be obtained even to the distal tip of the multicore optical fiber. Also, there is a risk of breakage, since conventional optical shape sensing devices do not include termination pieces, and/or the termination pieces cannot tolerate axial forces, as discussed above. Generally, the multicore optical fiber120may include a central optical core and at least two additional optical cores (not shown) helically wrapped around the central optical core, as would be apparent to one of ordinary skill in the art. The multicore optical fiber120enables shape sensing by tracking deformation along its length. The optical shape sensing device100further includes a force sensing region140integrated with the elongated outer body110. The force sensing region140, together with a processing unit150, is configured to sense an amount of axial force exerted on the distal end115of the elongated outer body110. In various configurations, the amount of axial force exerted on the distal end115may be determined by measuring changes in axial strain on the multicore optical fiber120at the force sensing region140, or by measuring torsion (twist) of the helically wrapped optical fibers of multicore optical fiber120at the force sensing region140, although other types of measurements may be incorporated without departing from the scope of the present teachings. The amount axial force exerted on the distal end115of the elongated outer body110is determined by the processing unit150, for example, which applies the axial strain measurement and/or the torsion measurement received from the force sensing region140to corresponding known algorithms. The axial strain, in particular, measured using the multicore optical fiber120is directly related to temperature changes and forces applied to the multicore optical fiber120. When constant temperature is assumed, then the measured axial strain on the central optical fiber is proportional to the axial force on the distal end115of the elongated outer body110. FBGs are well known to be capable of measuring forces exerted on FBG enabled devices in biological settings, for example. Usage of guidewires or other interventional instruments, configured according to various embodiments of the disclosure to measure axial forces for cardiovascular procedures, for example, such as chronic total occlusion (CTO) crossings, confirming tissue contact for ablations in the heart, transeptal puncture, and vessel wall interactions, helps to prevent tissue damage, since the amount of axial force being applied is accurately determined. FIG.2is a simplified schematic diagram of a cut-away view of an optical shape sensing device including a force sensing region, according to a representative embodiment. Referring toFIG.2, optical shape sensing device200includes an elongated outer body210, which includes flexible tubing211and rigid tube212attached to the flexible tubing211. In the depicted embodiment, the rigid tube212is attached to a distal end213of the flexible tubing211. The flexible tubing211enables the maneuvering of the optical shape sensing device200through a passage, as discussed above. The flexible tubing211may be formed of various flexible materials, such as polyethylene, polyether ether ketone, polypropylene, nylon, polyimide, acetal or acrylonitrile butadiene styrene, and the rigid tube212may be formed of various less flexible materials, such as nitinol, stainless steel, titanium, aluminum, and various metal or plastics, such as polyether ether ketone, polypropylene, nylon, polyimide, acetal, and acrylonitrile butadiene styrene, although different materials may be incorporated without departing from the scope of the present teachings. The optical shape sensing device200also includes multicore optical fiber120extending longitudinally through the elongated outer body210, and a termination piece130attached to a distal tip124of the multicore optical fiber120, as discussed above. The termination piece130is positioned within the rigid tube212, and includes the distal tip135, which may substantially coincide with a distal end215of the elongated outer body210. Shape sensing is enabled by the optical shape sensing device200along the multicore optical fiber120to the distal tip135of the termination piece130. The optical shape sensing device200further includes a force sensing region240integrated with the elongated outer body210. For example, the rigid tube212may be micromachined to have a proximal rigid section212A, a distal rigid section212B, and a middle elastic segment245located in between. Thus, the elastic segment245is located proximally from the termination piece130. In the depicted embodiment, the force sensing region240of the optical shape sensing device200coincides with the elastic segment245. The elastic segment245enables axial compression and expansion of the rigid tube212of the elongated outer body210responsive to an axial force Fzexerted on the distal end215of the elongated body210. Adhesive217binds the multicore optical fiber120to an inner surface of both the proximal rigid section212A of the rigid tube212(at a proximal side of the elastic segment245), and the distal rigid section212B of the rigid tube212(at a distal side of the elastic segment245). The adhesive217also binds the multicore optical fiber120to an inner surface of the termination piece130in the distal rigid section212B. The adhesive217may be an epoxy or an anaerobic adhesive material, for example, although different materials may be incorporated without departing from the scope of the present teachings. The design of the elastic segment245dictates the degree to which the optical shape sensing device200compresses or bends. In the depicted embodiment the elastic segment245comprises a pattern of slits formed around an outer circumference of the rigid tube212. The pattern of slits may be formed in the rigid tube212by3D printing, laser cutting, micro-machining, casting, or lithographic techniques, for example, although other slit formation techniques may be incorporated without departing from the scope of the present teachings. Also, the pattern of slits may be formed prior to attachment of the rigid tube212to the flexible tubing211. In alternative embodiments, the elastic segment245may comprise other types of flexible structures, such as a laser cut design (not shown) formed around the outer circumference of the rigid tube212, or a coil spring, as discussed below with reference toFIGS.6and7, for example. The force sensing region240, together with the processing unit150(not shown inFIG.2), is configured to sense the amount of axial force exerted on the distal end215of the elongated outer body210, which corresponds to the distal end of the rigid tube212. When the elastic segment245compresses, the bare (without adhesive217) multicore optical fiber120between the proximal and distal rigid sections212A and212B also compresses, and the axial strain in this area is used to calculate the applied force. Determination of the amount of axial force exerted on the distal end215involves measuring changes in axial strain on the central optical fiber of the multicore optical fiber120at the force sensing region240, as discussed above. FIG.3is a simplified schematic diagram of a cut-away view of an optical shape sensing device including a force sensing region, according to a representative embodiment. Referring toFIG.3, optical shape sensing device300is substantially the same as the optical shape sensing device200, except that a force sensing region340is located in a portion of the flexible tubing211immediately adjacent to a proximal end of the rigid tube212, next to the proximal rigid section212A, as opposed to coinciding with the elastic segment245. That is, the optical shape sensing device300includes the elongated outer body210, which includes the flexible tubing211and the rigid tube212attached to the flexible tubing211. The optical shape sensing device200also includes the multicore optical fiber120extending through the elongated outer body210, and a termination piece130attached to a distal tip124of the multicore optical fiber120, as discussed above, and positioned within the rigid tube212. As in the previous embodiment, shape sensing is enabled by the optical shape sensing device300along the multicore optical fiber120to the distal tip135of the termination piece130. The optical shape sensing device300further includes the elastic segment245located in the rigid tube212proximally from the termination piece130. Adhesive317binds the multicore optical fiber120to the inner surface of the proximal rigid section212A of the rigid tube212, but not to the distal rigid section212B. Accordingly, the multicore optical fiber120and the termination piece130are free to float within the distal rigid segment212B and the elastic segment245. Any compression (and axial strain) of the multicore optical fiber120responsive to an axial force Fzexerted on the distal end215of the elongated body210would therefore occur just proximally to the proximal rigid section212A of the rigid tube212, which is fixed to the multicore optical fiber120by the adhesive317. This compression (and axial strain) would be sensed through the force sensing region340. Determination of the amount of axial force exerted on the distal end215involves measuring changes in the axial strain on the central optical fiber of the multicore optical fiber120at the force sensing region340, as discussed above. The adhesive317may be an epoxy or an anaerobic adhesive material, for example, although different materials may be incorporated without departing from the scope of the present teachings. In some applications, the rigidity of the rigid tube212at the distal end215of the elongated outer body210inFIGS.2and3, for example, may limit the ability to maneuver the optical shape sensing device200or300in small lumens. Therefore, the force sensing region may be moved more proximally along the length of the multicore optical fiber120. However, in order to determine axial forces at the distal end215of the elongated outer body210, the axial forces must be transmitted along the flexible tubing211to the rigid tube212. FIG.4is a simplified schematic diagram of a cut-away view of an optical shape sensing device including a more proximally located force sensing region, according to a representative embodiment. Referring toFIG.4, optical shape sensing device400is substantially the same as the optical shape sensing device200, except that the relative locations of the flexible tubing211and the rigid tube212are reversed, with additional flexible tubing (not shown) on the proximal end of the rigid tube212, enabling the flexibility for navigation through passages. The elastic segment245is located between the proximal rigid section212A and the distal rigid section212B of the rigid tube212, and a force sensing region440of the optical shape sensing device400coincides with the elastic segment245. That is, the optical shape sensing device400includes the elongated outer body210′, which includes the flexible tubing211and the rigid tube212attached to the flexible tubing211at a proximal end216of the flexible tubing211(as opposed to being attached to the distal end213). The optical shape sensing device400also includes the multicore optical fiber120extending through the elongated outer body210′, and a termination piece130attached to a distal tip124of the multicore optical fiber120, as discussed above. The termination piece130is positioned within the flexible tubing211. Shape sensing is enabled by the optical shape sensing device400along the multicore optical fiber120to the distal tip135of the termination piece130. The optical shape sensing device400further includes the elastic segment245located in the rigid tube212proximally from the termination piece130and the flexible tubing211. Adhesive217binds the multicore optical fiber120to an inner surface of both the proximal rigid section212A of the rigid tube212, and the distal rigid section212B of the rigid tube212. The elastic segment245enables axial compression and expansion of the rigid tube212of the elongated outer body210′ responsive to an axial force Fzexerted on the distal end215of the elongated body210. No adhesive binds the termination piece130to the flexible tubing211. Accordingly, the multicore optical fiber120and the termination piece130are free to float within the flexible tubing211and the elastic segment245. Any compression (and axial strain) of the multicore optical fiber120responsive to an axial force Fzexerted on the distal end215of the elongated outer body210would therefore occur in the elastic segment245. Determination of the amount of axial force exerted on the distal end215involves measuring changes in the axial strain on the central optical fiber of the multicore optical fiber120at the force sensing region340, as discussed above. FIG.5is a simplified schematic diagram of a cut-away view of an optical shape sensing device including a force sensing region, according to a representative embodiment. Referring toFIG.5, optical shape sensing device500does not include a rigid tube, such rigid tube212. The multicore optical fiber120therefore extends entirely through flexible tubing (flexible tubing511). A force sensing region540of the optical shape sensing device500is located proximally to a section of adhesive517between the multicore optical fiber120and the inner surface of the flexible tubing511. More particularly, the optical shape sensing device500includes an elongated outer body510, which includes the flexible tubing511. The multicore optical fiber120extends through the flexible tubing511, and a termination piece130is attached to a distal tip124of the multicore optical fiber120, as discussed above. The termination piece130is also located within the flexible tubing511. Shape sensing is enabled by the optical shape sensing device500along the multicore optical fiber120to the distal tip135of the termination piece130. Adhesive517binds the multicore optical fiber120to the inner surface of the flexible tubing511proximally from the termination piece130. In the depicted embodiment, the adhesive517is not immediately adjacent to the termination piece130, but rather is located a distance from the termination piece130, which is sufficient to allow some floating of the multicore optical fiber120before the location of the adhesive517. In other words, the multicore optical fiber120and the termination piece130are free to float within the flexible tubing511prior to the adhesive517, and the multicore optical fiber120is free to float within the flexible tubing511after the adhesive517, as well. Any compression (and axial strain) of the multicore optical fiber120responsive to an axial force Fzexerted on the distal end515of the elongated outer body510would therefore occur just proximally to the proximal to the location at which the multicore optical fiber120is fixed to the inner surface of the flexible tubing511by the adhesive517. This compression (and axial strain) would be sensed through the force sensing region540. Determination of the amount of axial force exerted on the distal end515involves measuring changes in the axial strain on the central optical fiber of the multicore optical fiber120at the force sensing region540, as discussed above. The adhesive517may be an epoxy or an anaerobic adhesive material, for example, although different materials may be incorporated without departing from the scope of the present teachings. FIG.5shows a similar concept asFIG.4, but without the rigid tube212. The multicore optical fiber120is fixed directly to the flexible tubing511in one location by the adhesive517, and then any compression in the flexible tubing511will be transmitted to the fixed segment. Hence, the force sensing region540would occur proximally to the fixed section. Applying the adhesive517in a middle portion, for example, of a long elongated outer body510may be challenging, though. The fixed section defined by the adhesive517should be very small in comparison to the length of the elongated outer body510, and placing the adhesive517involves the multicore optical fiber120being pushed through several centimeters of the flexible tubing511. Alternative materials to the adhesive517may be, such as UV curable or heat curable glue, which would allow a smaller diameter elongated outer body510to be used. Accordingly, the multicore optical fiber120may be fixed to the flexible tubing511after it has been pushed through the flexible tubing511. In other words, use of UV curable or heat curable glue, for example, enables external determination of the location(s) at which the multicore optical fiber120is fixed to the flexible tubing511, even if the glue is located (but not cured) outside that location(s). FIG.6is a plan view of an optical shape sensing device including a force sensing region having a coil spring, according to a representative embodiment. Referring toFIG.6, optical shape sensing device600includes an elongated outer body610, which includes flexible tubing611and rigid tube612attached to the flexible tubing611. In the depicted embodiment, the rigid tube612is attached to a distal end613of the flexible tubing611. The flexible tubing611enables the maneuvering of the optical shape sensing device600through a passage, as discussed above. The optical shape sensing device600also includes multicore optical fiber120extending longitudinally through the elongated outer body610, and a termination piece (e.g., termination piece130, not shown inFIG.6) attached to a distal tip of the multicore optical fiber120, as discussed above. The termination piece is positioned within the rigid tube612, and includes the distal tip135, which may substantially coincide with a distal end615of the elongated outer body610. Shape sensing is enabled by the optical shape sensing device600along the multicore optical fiber120clear to the distal tip135of the termination piece. The optical shape sensing device600further includes a force sensing region640integrated with the rigid tube612of the elongated outer body610. The rigid tube612has a proximal rigid section612A, a distal rigid section612B, and a multithread coil spring645located in between, where the multicore optical fiber runs through the coil spring645. In the depicted embodiment, the force sensing region640of the optical shape sensing device600coincides with the coil spring segment645, which is the elastic segment of the elongated outer body610. That is, the coil spring645enables axial compression and expansion of the rigid tube612responsive to an axial force Fzexerted on the distal end615of the elongated body610. Use of the coil spring645enables the elastic segment to be longer than other types of elastic segments, such as a pattern of slits (e.g., elastic segment245) or a laser cut design. The force sensing region640, together with the processing unit150(not shown inFIG.6), is configured to sense the amount of axial force Fzexerted on the distal end615of the elongated outer body610, which corresponds to the distal end of the rigid tube612. When the coil spring645compresses, the optical fiber120between the proximal and distal rigid sections612A and612B also compresses, and the axial strain in this area is used to calculate the applied force. The optical fiber120may be fixed to the proximal and distal rigid sections612A and612B using adhesive (not shown inFIG.6), similar to the adhesive217discussed above. Determination of the amount of axial force exerted on the distal end615involves measuring changes in axial strain on the central optical fiber of the multicore optical fiber120at the force sensing region640, as discussed above. FIG.7is a simplified schematic diagram of a cut-away view of an optical shape sensing device including a force sensing region having a coil spring, according to a representative embodiment. Referring toFIG.7, optical shape sensing device700is substantially the same as the optical shape sensing device600, with the addition of proximal and distal rigid extensions614A and614B that extend within the coil spring645from the proximal and distal rigid sections612A and612B. Extending these solid parts (proximal and distal rigid extensions614A and614B) inside the coil spring645results in the axial strain induced in the multicore optical fiber120by the axial force Fzbeing larger than the axial strain induced in the coil spring645. More particularly, application of an axial force Fzresults in a compression of the rigid tube612assembly indicated by δd. The axial strain over the length (d2) of the coil spring645is ε2=δd/d2, whereas the axial strain over the length (d1) of the exposed portion of the multicore optical fiber120(i.e., the space within the coil spring645between proximal and distal rigid extensions614A and614B) is ε1=δd/d1. Since d2>d1, it follows that ε1>ε2, which will result effectively in increased force sensitivity in the force sensing region740of the optical shape sensing device700, e.g., as compared to the force sensing region640of the optical shape sensing device600. FIG.8Ais a simplified cross-sectional diagram of an optical shape sensing device including a force sensing region in which optical fiber has helical pattern, according to a representative embodiment. Referring toFIG.8A, optical shape sensing device800A includes an elongated outer body810, which includes proximal flexible tubing811, distal flexible tubing812attached to the proximal flexible tubing811, and distal tube813attached to the distal flexible tubing812. The proximal and distal flexible tubing811and812enable the maneuvering of the optical shape sensing device800A through a passage, as discussed above. The optical shape sensing device800A also includes multicore optical fiber820extending longitudinally through the elongated outer body810, and a termination piece830attached to a distal tip824of the multicore optical fiber820, as discussed above. The termination piece830is located within the distal tube813and includes a distal tip835, which may substantially coincide with a distal end815of the elongated outer body810. Shape sensing is enabled by the optical shape sensing device800along the multicore optical fiber820to the distal tip835of the termination piece830. The composition of the multicore optical fiber820is substantially the same as the multicore optical fiber120, discussed above. In the depicted embodiment, the multicore optical fiber820includes a helical portion821having a helical pattern. The helical portion821is embedded in compliant material812′ within the distal flexible tubing812, which increases axial sensitivity in multiple directions over other embodiments in which the multicore optical fiber has no helical patter. The helical portion821defines a deformation region845, and the force sensing region840of the optical shape sensing device800coincides with the deformation region845. The compliant material812′ may be silicon (Si), for example, although other materials with similar compliant properties may be incorporated without departing from the scope of the present teachings. Incorporation of the helical portion821engages multiple modes of deformation to provide higher resolution force-from-strain sensing. The deformation region845enables axial compression and expansion of the distal flexible tubing812(and the compliant material812′ therein) of the elongated outer body810responsive to an axial force Fzexerted on the distal end815of the elongated body810. The force sensing region840, together with the processing unit150(not shown inFIG.8), is configured to sense the amount of axial force exerted on the distal end815of the elongated outer body810. When the deformation region845compresses, the helical portion821of the multicore optical fiber820deforms in a manner reflected by the compliant material812′, and thus captured by the force sensing region840. Due to freedom of movement of the helical portion821within the compliant material812′, forces in directions other than an axial direction may be detected via the force sensing region840. FIG.8Bis a simplified cross-sectional diagram of an optical shape sensing device including a force sensing region in which optical fiber has helical pattern, according to a representative embodiment. Referring toFIG.8B, optical shape sensing device800B is substantially the same as the optical shape sensing device800A, with the addition of stiffening members818, formed along the distal flexible tubing812to increase lateral stiffness. The stiffening members818may be formed of any lightweight, substantially rigid material, such as titanium, polyether ether ketone, polypropylene, nylon, polyimide, acetal, or acrylonitrile butadiene styrene, for example. Also, the stiffening members818may be arranged on an outer surface of the distal flexible tubing812, as shown, or between the distal flexible tubing812and the compliant material812′, although other arrangements of the distal flexible tubing812may be incorporated without departing from the scope of the present teachings. FIG.9is a simplified cross-sectional diagram of an optical shape sensing device including a force sensing region for sensing torsion, according to a representative embodiment. Referring toFIG.9, optical shape sensing device900includes an elongated outer body910configured to maneuver through a passage, as discussed above. The elongated outer body910includes a proximal (first) substantially rigid portion911and a distal (second) substantially rigid portion912, separated by a space913between the proximal and distal substantially rigid portions911and912. The proximal and distal substantially rigid portions911and912may be formed of the same material(s) as the rigid tube212, for example, discussed above with reference toFIG.2. The optical shape sensing device900also includes multicore optical fiber120extending longitudinally through the elongated outer body910, and a termination piece130attached to the distal tip124of the multicore optical fiber120, as discussed above. The termination piece130is positioned within the distal substantially rigid portion92, and includes the distal tip135, which may substantially coincide with a distal end915of the elongated outer body910. Shape sensing is enabled by the optical shape sensing device900along the multicore optical fiber120to the distal tip135of the termination piece130. Adhesive917binds the multicore optical fiber120to portions of the inner surfaces of the proximal substantially rigid portion911and the distal substantially rigid portion912, respectively, adjacent the space913. The adhesive917prevents the multicore optical fiber120from sliding within the proximal and distal substantially rigid portions911and912. The adhesive917may be an epoxy or an anaerobic adhesive material, for example, although different materials may be incorporated without departing from the scope of the present teachings. In the depicted embodiment, the proximal substantially rigid portion911has a first angled edge911′ and the distal substantially rigid portion912has a second angled edge912′ complementary to the first angled edge911′. The first and second angled edges911′ and912′ face one another across the space913, and are shaped so that, when the elongated outer body910is compressed, the first and second angled edges911′ and912′ rotate with respect to one another, causing the multicore optical fiber120(adhered to the inner surfaces of the proximal and distal substantially rigid portions911and912) to twist within the space913. A force sensing region940, which substantially coincides with the space913, is configured to sense the amount of twisting (torsion) of the multicore optical fiber120in response to the axial force Fzexerted on the distal end915of the elongated body910. Generally, the twisting of the multicore optical fiber120causes the at least two additional optical fibers, helically wrapped around the central optical fiber of the multicore optical fiber120, to unravel or tighten to an extent proportional to the amount of axial force being exerted on the distal end915. Thus, in an embodiment, the extent of unraveling or tightening may be used to determine the axial force Fz. The force sensing region940, together with the processing unit150(not shown inFIG.9), is configured to sense the amount of axial force exerted on the distal end915of the elongated outer body910, which corresponds to the distal end of the distal substantially rigid portion912. When the proximal and distal substantially rigid portions911and912rotate with respect to one another, the multicore optical fiber120twists, the amount of twisting is used by the processing unit150to calculate the applied axial force, in accordance with a predetermined algorithm. Determination of torsion is described, for example, in U.S. Pat. No. 8,773,650 to Froggatt et al. (Jul. 8, 2014), and in U.S. Pat. No. 7,772,541 to Froggatt et al. (Aug. 10, 2010), both of which are hereby incorporated by reference in their entireties. FIG.10is a simplified cross-sectional diagram of an optical shape sensing device including a force sensing region for sensing buckling of the optical shape sensing device, according to a representative embodiment. Referring toFIG.10, optical shape sensing device1000includes an elongated outer body1010configured to maneuver through a passage, as discussed above. The elongated outer body1010includes a proximal (first) substantially rigid portion1011and a distal (second) substantially rigid portion1012, and flexible tubing1013connected between the proximal and distal substantially rigid portions1011and1012. The flexible tubing1013enables the proximal and distal substantially rigid portions1011and1012to move relative to one another, enabling bending or buckling of the elongated outer body1010. The proximal and distal substantially rigid portions1011and1012may be formed of the same material(s) as the rigid tube212, for example, and the flexible tubing1013may by formed of the same material(s) as the flexible tubing211, for example, discussed above with reference toFIG.2. The optical shape sensing device1000also includes multicore optical fiber120extending longitudinally through the elongated outer body1010, and a termination piece130attached to the distal tip124of the multicore optical fiber120, as discussed above. The termination piece130is positioned within the distal substantially rigid portion1012, and includes the distal tip135, which may substantially coincide with a distal end1015of the elongated outer body1010. Shape sensing is enabled by the optical shape sensing device1000along the multicore optical fiber120to the distal tip135of the termination piece130. The optical shape sensing device1000further includes a force sensing region1040integrated with the elongated outer body1010. More particularly, the force sensing region1040substantially coincides with a bendable portion of the flexible tubing1013(e.g., where there is no overlap between the flexible tubing1013and either of the proximal substantially rigid portion1011or the distal substantially rigid portion1012). The force sensing region1040is configured to sense an axial force exerted Fzon the distal end1015of the elongated body1010based on determining an amount of buckling experienced by the flexible tubing1013and sensed by the force sensing region1040in response to the axial force Fz. That is, the force sensing region1040senses the axial force Fzvia changes in curvature of the multicore optical fiber120, or strain on the multicore optical fiber120, within the flexible tubing1013resulting from buckling. Adhesive1017binds the multicore optical fiber120to portions of the inner surfaces of the proximal substantially rigid portion1011and the distal substantially rigid portion1012, respectively, adjacent the flexible tubing1013. The adhesive1017prevents the multicore optical fiber120from sliding within the proximal and distal substantially rigid portions1011and1012to enable a more accurate determination of buckling caused by application of the axial force Fz. The adhesive1017may be an epoxy or an anaerobic adhesive material, for example, although different materials may be incorporated without departing from the scope of the present teachings. The force sensing region1040, together with the processing unit150(not shown inFIG.10), is configured to sense the amount of axial force exerted on the distal end1015of the elongated outer body210, which corresponds to the distal end of the distal substantially rigid portion1012. When the flexible tubing1013buckles, the bare multicore optical fiber120also buckles, and the amount (or degree) of buckling is used by the processing unit150to calculate the applied axial force, in accordance with a predetermined algorithm. Buckling may be sensed, for example, through a change in the curvature of the multicore optical fiber. The greater the amount of buckling, the greater the curvature change. A calibration procedure may be used to model force as a function of curvature. Determination of curvature and changes thereto is described, for example, in U.S. Pat. No. 8,773,650 to Froggatt et al. (Jul. 8, 2014), and in U.S. Pat. No. 7,772,541 to Froggatt et al. (Aug. 10, 2010), both of which are hereby incorporated by reference in their entireties. In other embodiments, the design of the outer surface of a conventional optical shape sensing device (e.g., a guidewire or catheter shaft) may be modified. For example, conventional guidewires and catheters may be made of nitinol, which is “braided,” and then coated with different types of materials (e.g., soft and flexible or more rigid). That is, the entire outer surface or outer body of the optical sensing device may be braided in the same (conventional) manner, but the material covering the braided design may differ in flexibility in various sections, depending on anticipated functionality, respectively. Alternatively, or in addition, construction the braided design may differ in various sections to change flexibility. That is, the conventional braided design may still be used in the majority of the optical sensing device, while a relatively small section the nitinol may be formed into a spring-like design that compresses in response to applied axial forces. FIG.11Ais a simplified transparent plan view of an optical shape sensing device including a force sensing region, according to a representative embodiment. Referring toFIG.11A, optical shape sensing device1100A includes an elongated outer body1110, which includes braided design portions1111and a spring design portion1112formed integrally with and between the braided design portions1111. The spring design portion1112compresses in response to applied axial forces, such as axial force Fz. A multicore optical fiber (not shown) runs longitudinally through the elongated outer body1110, and is fixed to the braided design portions1111, e.g., using adhesive, on either end of the spring design portion1112. A termination piece130is attached to a distal tip of the multicore optical fiber, and includes a distal tip135, which may substantially coincide with a distal end1115of the elongated outer body1110. A force sensing region1140A of the optical shape sensing device1100substantially coincides with the spring design portion1112. The force sensing region1140, together with the processing unit150(not shown inFIG.11A), is configured to determine the amount of axial force exerted on a distal end1115of the elongated outer body1110by sensing compression of the spring design portion1112responsive to the axial force Fz. FIG.11Bis a simplified transparent plan view of an optical shape sensing device including a force sensing region, according to a representative embodiment. Referring toFIG.11B, optical shape sensing device1100B includes an elongated outer body1110′, which includes a braided design portion1111along substantially the entire length (i.e., there is not spring design portion). Rather, an elastic segment of the elongated outer body1110′ is provided by use of different materials covering the braided design portion1111. In the depicted embodiment, the elongated outer body1110′ is covered by a first material in first material segment1151, a second material in second material segment1152, a third material in third material segment1153, and a fourth material in fourth material segment1154. The first and third materials, which may be the same, are rigid or substantially rigid materials, and the third material is a standard material for covering a termination piece (e.g., termination piece130), such as standard PTFE, for example. The second material covering the second material segment1152is an elastic material, such as silicone or any biocompatible rubber-like material, for example. Accordingly, the second material segment1152compresses in response to applied axial forces, such as axial force Fz. A multicore optical fiber (not shown) runs longitudinally through the elongated outer body1110′, and is fixed to at least the first and third material segments1151and1153, e.g., using adhesive, on either side of the end of the second material segment1152. A termination piece130is attached to a distal tip of the multicore optical fiber, and includes a distal tip135, which may substantially coincide with a distal end1115′ of the elongated outer body1110′. A force sensing region1140B of the optical shape sensing device1100B substantially coincides with the second material segment1152. The force sensing region1140B, together with the processing unit150(not shown inFIG.11B), is configured to determine the amount of axial force exerted on a distal end1115′ of the elongated outer body1110′ by sensing compression of the second material segment1152responsive to the axial force Fz. FIG.12is a simplified cross-sectional diagram of an optical shape sensing device including multiple force sensing regions embedded in compliant material, according to a representative embodiment. Referring toFIG.12, optical shape sensing device1200includes an elongated outer body1210, which includes proximal flexible tubing1211, distal flexible tubing1212attached to the proximal flexible tubing1211, and distal tube1213attached to the distal flexible tubing1212. The proximal and distal flexible tubing1211and1212enable the maneuvering of the optical shape sensing device1200through a passage, as discussed above. The optical shape sensing device1200also includes multicore optical fiber1220extending longitudinally through the elongated outer body1210, and a termination piece1230attached to a distal tip1224of the multicore optical fiber1220, as discussed above. In the depicted embodiment, a portion of the multicore optical fiber1220is embedded in compliant material1212′ within the distal flexible tubing1212. The termination piece1230is located within the distal tube1213, and includes a distal tip1235, which may substantially coincide with a distal end1215of the elongated outer body1210. Shape sensing is enabled by the optical shape sensing device1200along the multicore optical fiber1220to the distal tip1235of the termination piece1230. The composition of the multicore optical fiber1220is substantially the same as the multicore optical fiber120, discussed above. The optical shape sensing device1200further includes multiple force sensing regions1241,1242,1243,1244and1245embedded in the compliant material1212′, surrounding the multicore optical fiber1220. Each of the force sensing regions1241to1245includes a solid element1248inside a corresponding perforation1249through the distal flexible tubing1212and the compliant material1212′. The solid element1248may be a metal bead, for example, and the compliant material1212′ may be silicon (Si), for example, although other compliant materials with similar properties, respectively, may be incorporated, without departing from the scope of the present teachings. The force of a contact on the termination piece1230and/or the distal flexible tubing1212(axial or lateral) pushes one or more of the solid elements1248inside the distal flexible tubing1212. This changes the position of the one or more solid elements1248, and thus the shape of the compliant material1212′, creating a small change in the shape of the optical shape sensing device1200corresponding to the contact point. In the example depicted inFIG.12, a substantial lateral force (not shown) has displaced at least the solid element1248of the force sensing region1245, such that it is in contact with the multicore optical fiber1220(changing the shape of the multicore optical fiber1220, as well as the shape of the compliant material1212′). The extent of the displacement is sensed by at least the force sensing region1245(and possibly one or more of the other force sensing regions1241-1244). Therefore, the force sensing regions124-1245, together with the processing unit150(not shown inFIG.12), are configured to sense the amount of lateral forces, as well as axial force, exerted on the termination piece1230and/or the distal flexible tubing1212. FIG.13is a simplified schematic diagram of a cut-away view of an optical shape sensing device including a force sensing region and a stopper, according to a representative embodiment. Referring toFIG.13, optical shape sensing device1300includes an elongated outer body1310, which includes flexible tubing1311and substantially rigid tube1312attached to the flexible tubing1311. In the depicted embodiment, the rigid tube1312is attached to a distal end of the flexible tubing1311, and may have varying degrees of rigidity, although the rigid tube1312is less flexible than the flexible tubing1311. The flexible tubing1311enables the maneuvering of the optical shape sensing device1300through a passage, as discussed above. The optical shape sensing device1300further includes a disk1358attached to distal inner tubing1357, which extends into a distal side of the rigid tube1312through a distal end1315of the elongated outer body1310. In an uncompressed state, the disk1358is spaced apart from the distal end1315(which may also be referred to as a stopper) by gap1318, as shown inFIG.13. The optical shape sensing device1300also includes multicore optical fiber120extending longitudinally through the elongated outer body1310, and termination piece130attached to the distal tip124of the multicore optical fiber120, as discussed above. The termination piece130is positioned within the rigid tube1312, and has a distal tip135. More particularly, the termination piece130and at least a portion of the multicore optical fiber120are positioned within the distal inner tubing1357, which is inside the rigid tube1312. The termination piece130and the at least a portion of the multicore optical fiber120are bound to the inside surface of the distal inner tubing1357using adhesive1316. In the uncompressed stated, the distal tip135(inside the distal inner tubing1357) extends beyond the distal end1315(stopper) of the elongated outer body1310, as discussed below. Shape sensing is enabled by the optical shape sensing device1300along the multicore optical fiber120clear to the distal tip135of the termination piece130. A force sensing region1340is integrated with the elongated outer body1310in the rigid tube1357. In an embodiment, the force sensing region1340is located between a proximal end of the distal inner tubing1357and a distal end of additional inner tubing1356located at a proximal side of the rigid tube1312. A portion of the multicore optical fiber120extends through the additional inner tubing1356, and is bound to an inner surface of the additional inner tubing1356by adhesive1317. Thus, the force sensing region1340is effectively defined by an area between the proximal end of the distal inner tubing1357and the distal end of the additional inner tubing1356. This focuses axial compression and expansion in the force sensing region1340within the defined area responsive to an axial force Fzexerted on the disk1358. The adhesive1316and1317may be an epoxy or an anaerobic adhesive material, for example, although different materials may be incorporated without departing from the scope of the present teachings. Accordingly, when the axial force Fzis exerted on the disk1358, the rigid tube1312and the multicore optical fiber120compress within the force sensing region120, and the gap1318becomes smaller (closes). Depending on the magnitude of the axial force Fz, the compression continues until the gap1318closes completely, that is, the disk1358is in physical contact with the distal end1315. Thus, the size of the gap1318limits the amount of axial force (and the extent of compression of the force sensing region1340) exerted on the termination piece130and the multicore optical fiber120, thereby protecting the multicore optical fiber120from breakage in the force sensing region1340or elsewhere. The gap size may be selected based on mechanical properties of the multicore optical fiber120and the termination piece130, as well as the maximum amount of force a user wants to detect. In addition, the force sensing region1340, together with the processing unit150(not shown inFIG.13), are configured to sense the compression and determine the amount of axial force exerted on the disk1358and/or the distal end1315of the elongated outer body1310. The axial strain in the area of the force sensing region1340is used to calculate the applied force. Determination of the amount of axial force exerted on the disk1358and/or the distal end1315involves measuring changes in axial strain on the central optical fiber of the multicore optical fiber120, as discussed above. While various embodiments have been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. A computer program may be stored/distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. Any reference signs in the claims should not be construed as limiting the scope.

11857269

DETAILED DESCRIPTION The various embodiments will be described in detail with reference to the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. References made to particular examples and implementations are for illustrative purposes, and are not intended to limit the scope of the invention or the claims. Various embodiments are directed to an integrated system for performing robotically-assisted surgery in conjunction with intra-operative imaging. In recent years, there has been increased interest in the field of robotically-assisted surgery in which robotic systems are used to aid in surgical procedures. However, such systems are generally characterized by high-cost and complexity and may also be limited in the types of procedures they can perform. Various embodiments include systems and methods for performing robotically-assisted surgery that may be characterized by improved usability, workflow and ease of use. The systems and methods of various embodiments may be used to perform a wide variety of surgical procedures in virtually any part of a patient's anatomy. A system100for performing robotically-assisted surgery according to one embodiment is shown inFIGS.1A-1C.FIGS.1A and1Care perspective views showing the first (i.e., front) side of the system100andFIG.1Bis a perspective view showing a second (i.e., rear) side of the system100. The system100includes at least one robotic arm101that is movable with respect to a patient103. In this embodiment, the system100includes two robotic arms101a,101bthat may be moved independently of one another. It will be understood that in other embodiments, the system100may include a single robotic arm or more than two robotic arms. The movements of the robotic arm(s)101a,101bmay be controlled by a controller105(e.g., a computer including a memory and processor for executing software instructions) that may be coupled to the robotic arm(s)101a,101bvia a wired or wireless link107. In this embodiment, the controller105for the robotic arms101a,101bis located in a workstation/mobile cart109that may include a display111and one or more user input devices100(e.g., touchscreen controller, keyboard, mouse, buttons, switches, etc.) to enable a user to control the operation of the system100. In this embodiment, each of the robotic arms101a,101bcomprises a multijoint arm that includes a plurality of linkages113connected by joints115having actuator(s) and optional encoder(s) to enable the linkages to bend, rotate and/or translate relative to one another in response to control signals from the control system105. A first end117of the robotic arm101a,101bmay be fixed to a structure40and a second end119of the arm may be freely movable with respect to the first end117. An end effector121is attached to the second end119of the robotic arm101a,101b. In some embodiments, the end effector121may be an invasive surgical tool, such as a needle, a cannula, a cutting or gripping instrument, an endoscope, etc., that may be inserted into the body of the patient. In other embodiments, as described in further detail below, the end effector121of the robotic arm101a,101bmay be a hollow tube or cannula that may receive an invasive surgical tool122(seeFIG.1C), including without limitation a needle, a cannula, a tool for gripping or cutting, an electrode, an implant, a radiation source, a drug and an endoscope. The invasive surgical tool122may be inserted into the patient's body through the hollow tube or cannula by a surgeon. An end effector121comprising a hollow tube or cannula may be made of a radiolucent material, such as a carbon-fiber or thermoplastic material. The patient103, which may be a human or animal patient, may be located on a suitable patient support60, which may be a surgical table as shown inFIGS.1A-1C. The patient support60in this embodiment is raised off the ground by a support column50. During a surgical procedure, the robotic arms101a,101bmay be located partially or completely within the sterile surgical field, and thus may be covered by a surgical drape or other sterile barrier (not shown for clarity). In embodiments, the end effector121(e.g., a hollow tube or cannula) may be a sterilized component that may be attached (e.g., snapped into) the end119of the robotic arm101over the drape. The end effector121may be a sterile, single-use (i.e., disposable) component that may be removed and discarded after use. The system100also includes an imaging device125that may be used to obtain diagnostic images of the patient103. The imaging device125may be located in proximity to both the patient103and the at least one robotic arm101a,101b(e.g., within 10 meters, such as less than 5 meters, including 0-3 meters from the patient103and arm(s)101a,101b), and is preferably located within the same room (e.g., an operating room). In the embodiment ofFIGS.1A-1C, the imaging device125includes a base20and a gantry40located above the base20. The gantry40in this embodiment includes a substantially O-shaped housing (i.e., a ring) defining a bore16. The gantry40includes one or more imaging components (not shown for clarity) located within the housing of the gantry40that are configured to obtain image data of at least a portion of an object (e.g., patient103) positioned within the bore16. In this embodiment, the first end117of each of the robotic arms101a,101bis attached to the imaging device125. In particular, each of the robotic arms101a,101bare attached to a first (i.e., front) side127of the gantry40, although it will be understood that the robotic arms101a,101bmay be mounted at other portions of the imaging device125or system100. In embodiments, the imaging device125may include one or more adaptors configured to receive a robotic arm101at one or more locations on the device125. The adaptor(s) may be molded or affixed (e.g., using fasteners or adhesive) to an outer surface of the device125. The first end117of a robotic arm101may be inserted into and secured by the adaptor. After use, the robotic arm(s)101may be released from the adaptor and removed from the imaging device125for transport and/or storage. For example, the robotic arms101a,101bmay be stored on and/or transported by the cart109. In embodiments, the imaging device125may be an x-ray computed tomography (CT) imaging device. The imaging components within the gantry40may include an x-ray source and an x-ray detector. The x-ray source and optionally the detector may rotate within the gantry40around the bore16to obtain x-ray image data (e.g., raw x-ray projection data) of an object located within the bore16. The collected image data may be processed using a suitable processor (e.g., computer) to perform a three-dimensional reconstruction of the object, which may be, for example, rendered on the display111. Examples of x-ray CT imaging devices that may be used according to various embodiments are described in, for example, U.S. Pat. No. 8,118,488, U.S. Patent Application Publication No. 2014/0139215, U.S. Patent Application Publication No. 2014/0003572, U.S. Patent Application Publication No. 2014/0265182 and U.S. Patent Application Publication No. 2014/0275953, the entire contents of all of which are incorporated herein by reference. It will be understood that these embodiments are provided as illustrative, non-limiting examples of imaging systems suitable for use in the present systems and methods, and that the present systems and methods may utilize various types of medical imaging devices. For example, alternatively or in addition to an x-ray CT device, the imaging device125may be an x-ray fluoroscopic imaging device, a magnetic resonance (MR) imaging device, a positron emission tomography (PET) imaging device, a single-photon emission computed tomography (SPECT), an ultrasound imaging device, etc. In embodiments, the imaging system125may be configured to move with respect to the patient103. For example, at least a portion of the imaging system125(e.g., the gantry40) may move with respect to the patient103to obtain images of a particular region of the patient's body, and may also be moved away from the region to facilitate a surgical procedure being performed within the region. In the embodiment shown inFIGS.1A-1C, the patient support60on which a patient103may be located is secured to the base20of the imaging system125by the column50, and the gantry40may translate with respect to the base20, the column50and the patient support60. This is illustrated inFIGS.2A-2C, which show the gantry40translated on the base20so that a portion of the patient103and patient support60are located within the bore16of the gantry40. In the embodiment ofFIGS.1A-2C, the column50is located on a first end of the base20and the patient support60attached to the column50is cantilevered over the base20so that the gantry40may translate over substantially the entire length of the patient support60. The gantry40is supported by a gimbal30that includes a pair of arms31,33that extend upwards from the base20and are connected to opposite sides of the gantry40. The gimbal30may include bearing surfaces that travel on rails23on the base20to provide the translation motion of the gimbal30and gantry40. A drive mechanism (not shown for clarity) may drive the translation of the gimbal30and gantry40. An encoder or similar sensing device may determine the translation position of the gantry40on the base20. In embodiments, the gantry40may tilt with respect to the gimbal30. In some embodiments, the patient support60and/or the column50may be translated as an alternative or in addition to translating the gantry40of the imaging system125. For example, the patient support60may be translated with respect to the column50, or the entire column50and patient support60may be translated with respect to the base20. In this way, the patient103may be moved into and out of the bore16of the gantry40. In some embodiments, the column50may be configured to raise and lower the height of the patient support60with respect to the base20. The patient support60may also be rotatable with respect to the base20, either by rotating the patient support60on the column50or by rotating the column50and patient support60with respect to the base20. The system100may also include a motion tracking apparatus129for tracking the position of at least one of the robotic arm(s)101a,101band the imaging system125in three-dimensional space. The tracking apparatus129may also track the position of the patient103as well as other objects, such as the patient support50and/or surgical tools122within the surgical area. Various systems and technologies exist for tracking the position (including location and/or orientation) of objects as they move within a three-dimensional space. Such systems may include a plurality of active or passive markers fixed to the object(s) to be tracked and a sensing device that detects radiation emitted by or reflected from the markers. A 3D model of the space may be constructed in software based on the signals detected by the sensing device. In the embodiment shown inFIGS.1A-2C, the motion tracking apparatus129is an optically-based motion tracking apparatus that includes an optical sensor (i.e. camera)131and one or more markers133. In this embodiment, the camera131is attached to the gantry40of the imaging device125and is oriented such that the camera131may look directly into the sterile surgical field. In other embodiments, the camera131may be mounted to another portion of the imaging device125or to another component of the system100, such as the patient support60, or may be mounted to a separate support structure. An advantage of the configuration shown inFIGS.1A-2Cis that the camera131may look down directly into the surgical field without being blocked. In embodiments, the camera131may be mounted to the end of an arm135that may include actuator(s) for moving the camera131so that the surgical field is maintained within the camera's field of view. For example, as the gantry40moves (e.g., translates) with respect to the patient103, the camera131may swivel on the arm135and/or the arm135itself may pivot, bend, extend and/or contract to maintain the surgical field within the field of view of the camera131. The markers133may comprise any active or passive marker that may be detected by the camera131. The markers133may be fixed to various objects to be tracked, such as the end effectors121of the robotic arms101a,101b, as shown inFIG.1C. One or more markers133may also be attached to surgical tools122to enable the position and orientation of the various surgical tools122within the surgical field to be tracked in real time during a surgical procedure. One or more markers133may also be attached to other objects, such as the patient103, the patient support60and/or the imaging device125. In embodiments, the markers133may be moire pattern markers that may provide measurement data for position and orientation using a single camera131using Moire Phase Tracking (MPT) technology. Each marker133may also include a unique identifier or code that may enable different objects within the camera's field of view to be uniquely identified and tracked. An example of an MPT-based tracking system is available from Metria Innovation Inc. of Milwaukee, Wisconsin. FIG.3is a system block diagram that schematically illustrates various components of the system100according to one embodiment. As discussed above, a first controller105may control the operation of one or more robotic arms101a,101b. The first controller105may receive feedback data (indicated by arrow201) from the robotic arm(s)101a,101bregarding the status and operation of the arms101a,101b. The feedback data may include sensor (e.g., encoder) data that may be used to determine the position and orientation of each of the joints115of the robotic arms101a,101b. The first controller105may send control signals (indicated by arrow203) to the robotic arm(s)101a,101bto control the movements of the arms101a,101b. The system100may also include a second controller205for controlling the operation of the imaging device125. The second controller205may receive feedback data (indicated by arrow207) regarding the status and operation of the imaging device125. The feedback data may include information as to the position and orientation of the imaging device125, such as the position (translation or tilt) of the gantry40and/or the position of the patient support60. The second controller205may also send control signals (indicated by arrow209) to various components of the imaging device125to control the operation of the imaging device125, including controlling the imaging device125to obtain image data211(e.g., a three-dimensional CT reconstruction) of an object located within the bore16of the gantry40. The image data211may be displayed on a display111. The system100may also include a third controller213for controlling the operation of the motion tracking apparatus129. The third controller213may receive data sensed by the camera131(indicated by arrow215) and based on this data may determine position and/or orientation data for each of the markers133within the field of view of the camera131. Based on the determined position and/or orientation of the markers133, a three-dimensional model219of various objects within the surgical space (e.g., the patient103, surgical tool(s)122, the end effector(s)121of the robotic arm(s)101a,101b, the imaging device125, etc.) may be generated. The third controller213may also send control signals (indicated by arrow217) to the camera131to control the operation of the camera131, such as by adjusting the camera's field of view. The first, second and third controllers105,205,213may communicate and share various data with one another, as indicated by arrows221,223and225. The sharing of data including positional data enables the controllers to operate in a common coordinate system. For example, the image data211of the patient103obtained by the imaging device125may be registered to the position data obtained by the motion tracking apparatus129, as is known in the field of surgical navigation systems. The position of one or more objects tracked by the motion tracking apparatus129may be shown on the display111, such as overlaying the display of image data211from the imaging device125. Further, the first controller105may determine the position of the robotic arm(s)101a,101bwith respect to the rest of the system100based on position data from the motion tracking apparatus129and/or the imaging device125. In embodiments, each of the controllers105,205,213may comprise separate computing devices, each including a memory and processor for performing the various functions described herein. The separate computing devices may communicate with one another via a suitable data link (e.g., Ethernet). In other embodiments, two or more of the controllers105,205,213may be integrated in a single computing device. A system100as described above may be used for performing surgical procedures on a patient103, which may be a human or animal patient. For example, the patient103may be provided on a patient support60(e.g., a surgical table), and the imaging device125may be used to obtain images of the patient103, such as a CT scan of a particular region of the patient's anatomy. This may include moving the gantry40of the imaging device125(e.g., translating the gantry40on the base20) so that a region of interest of the patient103is located within the bore16of the gantry40and operating the imaging components (e.g., x-ray source and detector) to obtain image data of the patient103. Alternately, the patient103may be moved into the bore16, such as by translating the patient support60into the bore16of the gantry40. The image data obtained by the imaging device125may be displayed on a display, such as the display111on the mobile cart109shown inFIGS.1A-2C. In embodiments, a surgeon or other clinician may interact with the image data shown in the display111using a suitable user interface/input device110(e.g., keyboard, mouse, touchpad, trackball, touchscreen, etc.). The clinician may be able to modify the image data displayed on the screen of the display111, such as by zooming in or out of a particular region, selecting or changing the particular projection angle(s) or slices in the case of a three-dimensional tomographic reconstruction. In embodiments, a surgeon/clinician may also select particular points on the displayed image using an input device. This is schematically illustrated inFIG.4, which shows a display111that displays an image401(e.g., a cross-sectional slice) of a region of interest of a patient103obtained using an imaging device125. The surgeon/clinician may identify and select at least one target point403in the displayed image401. The target point403may represent an end point for the insertion of a particular surgical tool122into the patient's body during a surgical procedure. The surgeon/clinician may also identify and select at least one entrance point405on the displayed image401. The entrance point405may represent a point on the exterior of the patient's body (e.g., the skin) through which the surgeon will insert the particular surgical tool122. The target point403and corresponding entrance point405thus define a unique trajectory407through the body of the patient103, as schematically illustrated by the dashed line inFIG.4. In embodiments, the surgeon may select the entrance point405and the trajectory407within the patient's body in order to facilitate the insertion of the surgical tool122to the target point403while minimizing damage to other tissue or organs of the patient103. As also shown inFIG.4, the trajectory407may also be extended outside of the patient's body to define a unique vector409in three-dimensional space extending from the selected entrance point405, as indicated by the dashed-dotted line inFIG.4. FIG.5is a process flow diagram that illustrates a method500for operating a robotic arm101to perform robotically-assisted surgery according to one embodiment. The method500may be performed using the system100described above with reference toFIGS.1A-4. For example, the system100may include at least one robotic arm101a,101bhaving an end effector121. The end effector121may comprise a hollow tube or cannula, as described above. Each of the robotic arms101a,101bmay be moveable with respect to a patient103and an imaging device125, where at least a portion of the imaging device125, such as a gantry40, is moveable with respect to the patient103to obtain imaging data of the patient103. The system100may also include a controller105for controlling the movements of the at least one robotic arm101a,101b. In block501of method500, the controller105may control the at least one robotic arm101to move the end effector121of the robotic arm101to a pre-determined position and orientation with respect to the patient103. The pre-determined position and orientation may be based on imaging data obtained by the imaging system125. For example, the imaging data may be used to determine a unique vector409in three-dimensional space corresponding to a desired insertion trajectory407for a surgical tool, as described above with reference toFIG.4. The controller105of the at least one robotic arm101a,101bmay translate this vector409into a coordinate system used for controlling the position and movement of the robotic arm101a,101bbased on positional information received from the imaging device125and/or from a motion tracking apparatus129, as described above with reference toFIG.3. The controller105may move the at least one first robotic arm101a,101bso that the end effector121of the robotic arm101a,101bis oriented along a pre-defined vector409. For example, as shown inFIG.1A, the end effector121of a first robotic arm101ais oriented along a first vector409a. The end effector121of a second robotic arm101bis oriented along a second vector409b. Each of the end effectors121may be positioned adjacent to a desired entrance point405for a surgical tool. A surgeon may then perform an invasive surgical procedure, which may include inserting one or more surgical tools through the end effectors121and into the body of the patient103. The position and orientation of the end effectors121may ensure that the surgical tools121follow the desired trajectory407(seeFIG.4) through the patient's body to reach the target area. In embodiments, a motion tracking apparatus129such as described above may be configured to track the at least one robotic arm101a,101bto ensure that the end effector(s)121maintain the pre-determined position and orientation with respect to the patient103. If an end effector121moves from the pre-determined position and orientation (e.g., due to the robotic arm being accidentally bumped), the motion tracking apparatus129may detect this movement and alert the surgeon or other clinician. Alternately or in addition, the motion tracking apparatus129may send a message to the controller105of the at least one robotic arm101a,101bindicating a detected deviation from the pre-determined position and orientation of the end effector121. The controller105may then move the robotic arm101a,101bto compensate for the detected deviation. In some embodiments, the motion tracking apparatus129may also track the patient103(e.g., where a plurality of markers133are placed on the patient103) to determine whether the patient103has moved relative to the end effector121. The motion tracking apparatus129may notify the surgeon when the patient103moves by more than a predetermined amount. In some embodiments, the motion tracking apparatus129may send message(s) to the controller105of the robotic arms(s)101a,101bregarding detected movements of the patient103. Such movements may include, for example, motion of the patient103corresponding to the patient's breathing. The controller105may move the robotic arm(s)101a,101bto compensate for any such movement (e.g., to maintain the end effector121in the same position and orientation with respect to the selected entrance point405on the patient's body). During a surgical procedure, the motion tracking apparatus129may also be used to track a variety of objects, including surgical tools122, within the surgical area. For example, as discussed above, various surgical tools122may be provided with markers122that enable the motion tracking system129to identify the tools and continually track their movements in three-dimensional space. Thus, as a tool122is inserted through an end effector121and into the patient's body, the motion tracking system129may use the detected position of the marker(s)133and a known geometry of the tool122to determine the depth of insertion of the tool122into the body. This may be displayed on the display111of the system100(e.g., overlaying the image data previously obtained from the imaging device125) and may aid the surgeon in determining whether the surgical tool122has been inserted to the desired depth in the patient's body. In block503of method500, the controller105may determine that at least a portion of the imaging device125is moving with respect to the patient103. For example, after obtaining imaging data of the patient103, the gantry40of the imaging device125may be translated away from the surgical area as shown inFIGS.1A-1Cto provide easier access to the surgical area for performing a surgical procedure. The robotic arm(s)101a,101bmay then be moved to a first position as shown inFIGS.1A-1C, with the end effector(s)121arranged in a pre-determined position and orientation with respect to the patient103. At a later time, the surgeon may wish to obtain additional image data of the patient103(e.g., to confirm the location of a surgical tool122within the patient103), and the gantry40may be translated back over the surgical area such as shown inFIGS.2A-2Cto perform an updated imaging scan. Alternately, following the initial imaging scan, the robotic arm(s)101a, and101bmay be moved into position on the patient103as shown inFIGS.1A-1Cwhile the gantry40is still located over the surgical area. The gantry40may then be moved (e.g., translated) out of the surgical area as shown inFIGS.2A-2Cbefore performing the surgical procedure. In either case, the controller105may determine that at least a portion of the imaging device (e.g., the gantry40) is moving with respect to the patient103based on a signal that may be received, for example, from the imaging device125, the motion tracking system129and/or from a user via a user input mechanism. In block505of method500, the controller105may control the at least one robotic arm101a,101bto move a first portion of the at least one robotic arm101a,101bwhile the imaging device125moves with respect to the patient103while maintaining the end effector121of the arm in the pre-determined position and orientation (e.g., vector409) with respect to the patient103. Thus, in an embodiment such as shown inFIGS.1A-2C, where the first end117of the arm101is attached to the portion of the imaging device125that moves with respect to the patient103(i.e., the gantry40), the controller105may control the movements of the arm101such that as the first end117of the arm moves towards or away from the patient103, the end effector121maintains its original position and orientation with respect to the patient103. In embodiments, the controller105may control the movement of the first portion of the arm101a,101bsuch that the arm101a,101bdoes not collide with either the imaging device125or the patient103during the movement of the arm. For example, as the imaging device125and robotic arms101a,101bmove from the position as shown inFIGS.1A-1Cto the position as shown inFIGS.2A-2C, at least a portion of the arms101a,101bincluding the end effectors121are located inside the bore16of the gantry40. The controller105may control the movement of each of the arms101a,101bso that as the gantry40advances towards the patient, none of the joints115of the arms101a,101bcollide with the side wall or inner diameter of the ring or with the patient103. The controller105may control the movement(s) of the arm(s)101a,101bin accordance with a motion planning algorithm that utilizes inverse kinematics to determine the joint parameters of the robotic arm that maintain the position and orientation of the end effector121while avoiding collisions with the imaging device125and the patient103. In embodiments, the controller105may determine the position of each of the robotic arms101a,101bin relation to the gantry40based on position data received from the imaging device125(e.g., indicating the translation and/or tilt position of the gantry40with respect to the base20). Alternately or in addition, the controller105may utilize position information received from the motion tracking apparatus125. As discussed above, the motion tracking system129may be used to construct a three-dimensional model (e.g., a CAD model) of the various objects being tracked by the motion tracking apparatus129. The sharing of data between the robotic system, the imaging device and the motion tracking apparatus may enable these systems to operate in a common coordinate system. In some embodiments, the position of the patient103may be defined using a freehand technique. For example, prior to commencement of the surgical procedure, the surgeon or other clinician may use the second (i.e., distal) end119of a robotic arm101to manually trace across the external surface of the patient103, such as around the surgical area. This may be used to define a three-dimensional boundary surface in the common coordinate system into which no portion of the at least one robotic arm101a,101bmay enter. This technique may also be used to define boundary surfaces corresponding to other objects and components of the system100proximate to the surgical area, such as the patient support60or portions of the imaging system125. In other embodiments, the motion tracking apparatus129may be used to define the boundary surface corresponding to the patient103, such where a plurality of markers133are placed in different locations on the patient103proximate to the surgical area and are tracked by the camera131. The positions of the markers133tracked by the motion tracking apparatus129may be used to define a three-dimensional boundary surface into which the robotic arm101a,101bmay not enter. In some cases, the controller105of the at least one robotic arm101a,101bmay determine that it is not possible to move a robotic arm without either changing the position or orientation of the end effector121with respect to the patient103, or some part of the arm colliding with the imaging device125or the patient103. For example, a translation of the gantry40may result in the arm101being extended beyond its maximum length. In other cases, the controller105may determine that no set of joint movements are possible to avoid collisions while maintaining the end effector in a fixed position and orientation. In such a case, the controller105may issue an alert that may be perceived by the surgeon or other clinician, and may preferably also send a signal to the imaging device125to stop the motion of the gantry40. As the gantry40moves with respect to the patient103, the camera131may also move to maintain the surgical area within the field-of-view of the camera131. In the embodiment ofFIGS.1A-2C, for example, where the camera131is attached to the gantry40by arm135, the camera131may include an actuator (e.g., a DC motor-based actuator) that causes the camera131to pivot on the arm135to keep the camera131pointed down into the surgical area while the camera131moves with the gantry40. This may enable the motion tracking apparatus129to continually track the position of objects within the surgical area as the gantry40and robotic arms101a,101bmove. Thus, the motion tracking apparatus129may provide a redundant safety feature in that if the motion tracking apparatus129detects a movement of an end effector121from the pre-determined position and orientation with respect to the patient103, the surgeon or other clinicians may be promptly notified. In embodiments, when the motion tracking apparatus129detects a change in position or orientation of the end effector121with respect to the patient103by more than a threshold amount, the motion tracking apparatus129may send a message to the imaging system125and the controller105of the robotic arm(s) to stop all motion of the system100. When the gantry40is moved such that the patient103is located in the bore16of the gantry40, the imaging device125may be operated to obtain imaging data of the patient103(e.g., a CT scan of at least a portion of the patient103). The system100may therefore be configured as shown inFIGS.2A-2C, with the gantry40moved over the surgical area and at least a portion of the robotic arms101a,101bincluding the end effectors121are located within the bore16. In embodiments, the end effectors121may comprise a radiolucent material so as not to block x-rays. The updated image data may be shown on the display111, and may enable the surgeon to confirm the location of a surgical tool122inserted into the patient103. After the image(s) are acquired by the imaging device125, the gantry40may be moved out of the surgical area, such as by translating the gantry40to the position as shown inFIGS.1A-1C. The controller105of the robotic arms101a,101bmay again control the robotic arms to maintain the predetermined position and orientation of the end effectors121with respect to the patient103while the gantry40translates with respect to the patient. An alternative embodiment of a system100for robotically-assisted surgery is shown inFIGS.6A-6C and7A-7C. The system100in this embodiment is substantially identical to the system100described above with reference toFIGS.1A-2C. This embodiment differs from the embodiments described above in that there is a single robotic arm101(rather than the pair of arms101a,101bshown inFIGS.1A-2C). Similar to the embodiment ofFIGS.1A-2C, the robotic arm101aand the camera131for the motion tracking system129are attached to the gantry40of the imaging device125. However, in this embodiment, the robotic arm101and the camera131are attached to the side of the gantry that faces away from the patient103. The configuration as shown inFIGS.6A-6C and7A-7Cmay be advantageously used, for example, for a cranial surgical procedure (e.g., neurosurgery, deep brain stimulation, insertion of an external ventricular drain, etc.). As shown inFIGS.6A-6C, for example, the head601of the patient103may be stabilized at one end of the patient support60. The head601may be located within the bore16of the gantry40of the imaging device125for obtaining pre-operative or intra-operative image data. The robotic arm101may be moved to a position such that the end effector121is in a predetermined position and orientation with respect to the patient103, as described above. The gantry40may be moved down along the length of the patient's body to provide easier access to the surgical area, as shown inFIGS.7A-7C. The controller105of the robotic arm101may control the movements of robotic arm101such that the end effector121is maintained in the pre-determined position and orientation with respect to the patient103while the gantry40moves. As shown inFIGS.7A-7C, this may include a stretching out or unfolding of the arm. Similarly, as the gantry40translates towards the head601of the patient103the joints of the arm101may be folded up as shown inFIGS.6A-6C. In either case, the controller105of the robotic arm101may use inverse kinematics to ensure that the position and orientation of the end effector121with respect to the patient103is maintained without any portion of the arm101colliding with either the imaging device125or the patient103. As shown inFIGS.6A-7C, the camera131of the motion tracking apparatus129and/or the arm135to which the camera131is attached may move in response to the movement of the gantry40to maintain the surgical area within the field-of-view of the camera131. Yet another embodiment of a system100for robotically-assisted surgery is shown inFIGS.8A-8D and9A-9B. The system100in this embodiment is substantially identical to the system100as previously described. This embodiment differs from those described above in that a pair of robotic arms101a,101bare attached to the patient support60rather than to the gantry40of the imaging device125. The camera131for the motion tracking system129is attached to the gantry40of the imaging device125. The robotic arms101a,101bmay be attached at any suitable location on the patient support60, such as on surgical rails801that extend along the sides of the patient support60. In embodiments, an adaptor803may be secured to a surgical rail801, and the robotic arm may be snapped into or otherwise secured to the adaptor. The operation of the embodiment shown inFIGS.8A-8D and9A-9Bmay be similar to the previous embodiments.FIGS.8A-8Dshow the gantry40translated over the surgical area andFIGS.9A-9Bshow the gantry40translated away from the surgical area in order to allow the surgeon access to the surgical area. In this embodiment, the robotic arms101a,101bare attached proximate to the distal end of the patient support60(i.e., opposite the support column50). Thus, as shown inFIGS.8A-8D and9A-9B, the robotic arms101a,101bextend into or through the bore16of the gantry40in order to move the end effectors121to the pre-determined position and orientation with respect to the patient103. A difference between the embodiment shown inFIGS.8A-8Dand the previous embodiments is that because the robotic arms101a,101bare attached to the patient support60rather than the gantry40, the robotic arms101a,101bmay not need to move with respect to the patient103once the end effectors121are moved to the predetermined position and orientation. The controller105of the robotic arms101a,101bmay move the end effectors121to the pre-determined position and orientation such as shown inFIGS.8A-8D and9A-9Bwithout colliding the arms101a,101bwith either the imaging system125or the patient103. The arms101a,101bmay be moved to a configuration such that they will not collide with the gantry40as the gantry40moves (e.g., translates) with respect to the patient103, such as between the positions shown inFIGS.8A-8D and9A-9B, respectively. Alternately, the arms101a,101bmay be moved to an initial configuration with the end effectors121in the pre-determined position and orientation with respect to the patient103, and a portion of the arm(s)101a,101bmay be moved to avoid colliding with the gantry40and the patient103while maintaining the position and orientation of the end effectors121when the gantry40moves with respect to the patient. In this embodiment, the camera121of the motion tracking apparatus129is attached to the gantry40by arm135. As shown inFIGS.8A-8D and9A-9B, the camera131and/or the arm135may move in response to the movement of the gantry40to maintain the surgical area within the field-of-view of the camera131. Yet another embodiment of a system100for robotically-assisted surgery is shown inFIGS.10A-10C and11A-11C. In this embodiment, the patient support60is configured for a patient103in a seated position. A robotic arm101and a camera131for the motion tracking apparatus129are both mounted to the patient support60. In this embodiment, the robotic arm101and camera131are attached to surgical rails801extending along opposite sides of the patient support60.FIGS.10A-10Cshow the gantry40of the imaging device125translated away from the patient103, andFIGS.11A-11Cshow the gantry40translated to the patient103such that the surgical area is located within the bore16. The gantry40is tilted with respect to the gimbal30in this embodiment. The operation of the system100in the embodiment shown inFIGS.10A-10C and11A-11Bmay be substantially identical to the embodiments described above. The robotic arm101may be moved to a position such that the end effector121is in a predetermined position and orientation with respect to the patient103, as described above. The camera131and arm135may be positioned such that the camera131is looking into the surgical area. If an imaging scan is desired, the gantry40which is tilted on the gimbal30may be translated towards the patient103, such as shown inFIGS.11A-11C. The controller105of the robotic arm101may use inverse kinematics to move the robotic arm101to maintain the position and orientation of the end effector121with respect to the patient103without any portion of the arm101colliding with either the imaging device125or the patient103. In some embodiments, the patient support60may be rotatable with respect to the imaging device125, such as shown inFIGS.12A-12B, which may provide the surgeon with additional space for performing a surgical procedure.FIGS.12A-12Bshow the patient support60rotated 90° with respect to the imaging device125. When an additional imaging scan is desired, the patient support60may be rotated back to the position as shown inFIGS.10A-10C, and the gantry40may be translated over the patient103to obtain the imaging scan, as shown inFIGS.11A-11C. In this embodiment, the robotic arm101is mounted to the patient support60and thus moves with the patient support60as it rotates. In other embodiments, the robotic arm101may be mounted to another structure, such as the imaging device125or to a separate support structure, and the controller105of the robotic arm101may be configured to move the robotic arm101to maintain the end effector121in the pre-determined position and orientation with respect to the patient103as the patient support60rotates. As discussed above, the robotic arm101may be attached anywhere on the system100, such as the on the gantry40, the patient support60, the support column50, the base20or the gimbal30. Mounting a robotic arm on the gimbal30may enable the robotic arm101to remain in close proximity to the gantry40and easily extend into the bore16of the gantry40without the weight of the robotic arm101being distributed onto the gantry40itself, which may be weight balanced. In addition, attaching the robotic arm101to the gimbal30may enable the gantry40to be tilted with respect to the patient without also tilting the first end117of the robotic arm101with respect to the patient. One or more robotic arms101may be mounted directly to the gimbal30(e.g., proximate to the end(s) of one or both of the arms31,33that attach to opposing sides of the gantry40). Alternately, a plate or other support member may be attached to and extend from an arm31,33of the gimbal30, and the robotic arm101may be mounted to the plate/support member. In an embodiment shown inFIGS.13A-13D, a support member1300may extend from the gimbal30(e.g., from the end of an arm31,33of the gimbal30) and at least one robotic arm101may be mounted to the support member1300. In embodiments, the support member1300may extend at least partially around an outer circumference of the gantry40. In the embodiment ofFIGS.13A-13D, the support member1300comprises a curved rail that extends around the outer circumference of the gantry40. In this embodiment, the support member1300forms a semicircular arc that extends between the ends of the respective arms31and33of the gimbal30. The semicircular support member1300may be concentric with the outer circumference of the gantry40. A bracket mechanism1301may be located on the support member1300and may include a mounting surface1303for mounting the first end117of the robotic arm101to the bracket mechanism1301. As shown inFIGS.13A-13D, the mounting surface1303may project from the side of the support member and may be upwardly angled as shown inFIGS.13A-13D. This may provide additional clearance for the “tilt” motion of the gantry40relative to the gimbal30. The bracket mechanism1301and the robotic arm101attached thereto may be moved to different positions along the length of support member1300(e.g., any arbitrary position between the ends of the arms31,33of the gimbal30) and may be fixed in place at a particular desired position along the length of the support member1300. This is schematically illustrated inFIGS.13C and13Dwhich are perspective and front views of the system100illustrating the bracket mechanism1301and the robotic arm101in a first position and a second position (indicated by phantom) on the support member1300. In some embodiments, the bracket mechanism1301may be moved manually (e.g., positioned by an operator at a particular location along the length of the support member1301and then clamped or otherwise fastened in place). Alternately, the bracket mechanism1301may be automatically driven to different positions using a suitable drive mechanism (e.g., a motorized belt drive, friction wheel, gear tooth assembly, cable-pulley system, etc., not shown inFIGS.13A-13D). The drive mechanism may be located on the bracket mechanism1301, the support member1300and/or the gimbal30, for example. An encoder mechanism may be utilized to indicate the position of the bracket mechanism1301and the first end117of the robotic arm101on the support member1300. Although the embodiment ofFIGS.13A-13Dillustrates one robotic arm101mounted to the support member1300, it will be understood that more than one robotic arm may be mounted to the support member1300via respective bracket mechanisms1301. FIG.13A-13Dalso illustrates a motion tracking apparatus1305which is similar to the motion tracking apparatus described above. In this embodiment, the motion tracking apparatus1305includes a stereoscopic optical sensor device1304that includes two or more IR cameras1306,1308attached to the gantry40of the imaging device. The optical sensor device1304may include one or more IR sources (e.g., diode ring(s)) that direct IR radiation into the surgical field, where the IR radiation may be reflected by markers and received by the cameras1306,1308. As shown inFIG.13A, a plurality of markers1307may be attached to the patient to form a “reference arc” that enables the cameras1306,1308to track the patient. The optical sensor device1305may include a two-axis robotic system to enable the cameras1306,1308to tilt and pan (i.e., rotate up-and-down and side-to-side) such that the reference arc on the patient may be maintained in the center of the cameras' field of view. A second set of markers1309may be attached to the second end119of the robotic arm101or to the end effector121to enable the tracking system to track the end effector121. The second set of markers1309preferably comprises four or more non-coplanar markers in a fixed, known geometric relationship with each other and to the end effector121, which enables both the position (x, y, z) and the orientation (yaw, pitch, roll) of the end effector121to be fully resolved. Similar sets of markers may be provided on any instruments or other objects brought into the surgical field to allow these objects to be tracked. In the embodiment ofFIGS.13A-13D, the optical sensor device1304is mounted to the first (i.e., front) side127of the gantry40via a second support member1311. The second support member1311may be a curved (e.g., semicircular) rail that may be attached to an upper portion of the gantry40to enable the cameras1306,1308to look down into the surgical field. The optical sensor device1304may be movable to different positions along the second support member1311, either manually or using a drive system. This may provide flexibility so that the robotic arm101may be translated to any location on support member1300while the optical sensor device1304may be translated to one side or the other of the robotic arm axis so that the cameras1306,1308may remain pointed down into the surgical field without being occluded by the end of the robotic arm101. Other motion tracking apparatuses, such as the apparatus129described above with reference toFIGS.1A-12B, could be utilized in the system ofFIGS.13A-13D. FIGS.14A-14Cillustrate an alternative embodiment of a system100for performing robotically-assisted surgery that includes at least one robotic arm101mounted to an imaging system1400. In this embodiment, the imaging system1400includes an O-shaped imaging gantry1401that is mounted to a support structure1403in a cantilevered fashion. The imaging system1400may be an x-ray imaging system that may be used to obtain 2D fluoroscopic images and/or 3D tomographic images of an object located within the bore16of the gantry. At least one of an x-ray source and an x-ray detector (not visible inFIGS.14A-14C) may rotate around the interior of the gantry1401to obtain images of an object within the bore16from different projection angles. The support structure1403may comprise a mobile cart1406that is attached to one side of the gantry1401via an attachment mechanism1405. The attachment mechanism1405may include one or more motorized systems that enable the gantry1401to translate and/or rotate with respect to at least a portion of the cart1406. For example, in embodiments the gantry1401may be raised or lowered relative to the cart1406and/or may be translated over a limited range-of-motion along the z-axis (i.e., into and out of the page inFIG.14A) relative to the cart1406. In addition, in some embodiments the gantry1401may be rotated with respect to the cart1406along one or more axis. For example, the gantry1401may be tilted with respect to the cart1406about a horizontal axis extending through the attachment point between the gantry1401and cart1406and/or may have a “wag” rotation about a vertical axis with respect to the cart1406. One or more robotic arms101may be attached anywhere on the imaging system1400ofFIGS.14A-14C, such as the on the gantry1401, the cart1406or the attachment mechanism1405. In an embodiment shown inFIGS.14A-14C, the robotic arm101is attached to a support member1407which may be similar to the support member1300described above with reference toFIGS.13A-13D. In this embodiment, the support member1407extends from the attachment mechanism1405, although the support member1407may extend from any portion of the cart1406. The support member1407in this embodiment is a semicircular segment that extends concentrically over an upper portion of the gantry1401. The support member1407and the robotic arm101secured thereto may translate with the translation of the gantry1401along at least one axis (e.g., up and down translation) relative to the cart1406. In embodiments, the gantry1401may be able to rotate (e.g., tilt) with respect to the cart1406without the support member1407and robotic arm101also rotating. The robotic arm101may be attached to the support member1407using a bracket mechanism1301as described above. The bracket mechanism1301and robotic arm may be moved to any arbitrary position along the length of the support member1407. In addition, the system may include a tracking system comprising an optical sensor device1304mounted to a side of the gantry1401via a second support member1313, as is described above with reference toFIGS.13A-13D. The optical sensor device1304may be moveable to different positions along the length of the second support member1313, as described above. Other motion tracking apparatuses, such as the apparatus129described above with reference toFIGS.1A-12B, could be utilized in the system ofFIGS.14A-14C. FIGS.15A-15Dillustrate another alternative embodiment of a system100for performing robotically-assisted surgery that includes at least one robotic arm101mounted to an imaging system1500. In this embodiment, the imaging system1500is a C-arm device that includes an x-ray source1501and a detector1503connected to one another by a C-shaped connecting member1505. The C-shaped connecting member1505is coupled to a support structure1507, which in this embodiment comprises a mobile cart1509. An attachment mechanism1511attaches the C-shaped connecting member1505to the cart1509such that the attachment mechanism1511together with the source1501, detector1503and C-shaped connecting member1505may be rotated in a first direction (i.e., into and out of the page inFIG.15A) relative to the cart1509. In some embodiments, the source1501, detector1503and C-shaped connecting member1505may also rotate in a second direction (i.e., within the plane of the page inFIG.15A) relative to the attachment mechanism1511and the cart1509. As discussed above, the cart1509may be a mobile cart and may be used to move the entire imaging system1500to a desired position and orientation. The source1501and detector1503may be used to obtain x-ray images, such as 2D fluoroscopic images, of an object positioned between the source1501and detector1503from a variety of different projection angles. One or more robotic arms101may be attached anywhere on the imaging system1500ofFIGS.15A-15D, such as the on the cart1509, the attachment mechanism1511or the C-shaped connecting member1505. In an embodiment shown inFIGS.15A-15D, the robotic arm101is attached to a support member1513which may be similar to the support members1300and1407described above with reference toFIGS.13A-13D and14A-14C. In this embodiment, the support member1513extends from the cart1509. The support member1513in this embodiment is a curved (e.g., semicircular) segment that extends from the cart1509at least partially above the source1501, detector1503and the C-shaped connecting member1505. The support member1513may be concentric with the C-shaped connecting member1505. The support member1513may be located such that the source1501and detector1503may freely rotate about one or more axes without contacting the support member1513. The robotic arm101may be attached to the support member1513using a bracket mechanism1301as described above. The bracket mechanism1301and robotic arm101may be moved to any arbitrary position along the length of the support member1513. In addition, the system may include a tracking system comprising an optical sensor device1304mounted to a side of the gantry1401via a second support member1515. The second support member1515may be a second curved (e.g., semicircular) segment that extends from the cart1509at least partially above the source1501, detector1503and the C-shaped connecting member1505. The second support member1515may extend parallel to support member1513, as shown inFIGS.15A-15C. In this embodiment, the second support member1515extends for a shorter length than support member1513, although it will be understood that the second support member1515may extend for the same or a greater length than support member1513. The optical sensor device1304may be moveable to different positions along the length of the second support member1515, as described above. Alternately, both the robotic arm101and the optical sensor device1304may be mounted to the same support member (e.g., support member1513). Also, other motion tracking apparatuses, such as the apparatus129described above with reference toFIGS.1A-12B, could be utilized in the system ofFIGS.15A-15D. FIG.16is a system block diagram of a computing device useful to perform functions of a processing control unit, such as controllers105,205and213described above. While the computing device1600is illustrated as a laptop computer, a computing device providing the functional capabilities of the computer device1600may be implemented as a workstation computer, an embedded computer, a desktop computer or a handheld computer (e.g., tablet, a smartphone, etc.). A typical computing device may include a processor1601coupled to an electronic display1604, a speaker1606and a memory1602, which may be a volatile memory as well as a nonvolatile memory (e.g., a disk drive). When implemented as a laptop computer or desktop computer, the computing device1600may also include a floppy disc drive, compact disc (CD) or DVD disc drive coupled to the processor1601. The computing device1600may include an antenna1610, a multimedia receiver1612, a transceiver1618and/or communications circuitry coupled to the processor1601for sending and receiving electromagnetic radiation, connecting to a wireless data link, and receiving data. Additionally, the computing device1600may include network access ports1624coupled to the processor for establishing data connections with a network (e.g., LAN coupled to a service provider network, etc.). A laptop computer or desktop computer1600typically also includes a keyboard1614and a mouse pad1616for receiving user inputs. The foregoing method descriptions are provided merely as illustrative examples and are not intended to require or imply that the steps of the various embodiments must be performed in the order presented. As will be appreciated by one of skill in the art the order of steps in the foregoing embodiments may be performed in any order. Words such as “thereafter,” “then,” “next,” etc. are not necessarily intended to limit the order of the steps; these words may be used to guide the reader through the description of the methods. Further, any reference to claim elements in the singular, for example, using the articles “a,” “an” or “the” is not to be construed as limiting the element to the singular. The various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention. The hardware used to implement the various illustrative logics, logical blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but, in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. Alternatively, some steps or methods may be performed by circuitry that is specific to a given function. In one or more exemplary aspects, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on as one or more instructions or code on a non-transitory computer-readable medium. The steps of a method or algorithm disclosed herein may be embodied in a processor-executable software module executed which may reside on a non-transitory computer-readable medium. Non-transitory computer-readable media includes computer storage media that facilitates transfer of a computer program from one place to another. A storage media may be any available media that may be accessed by a computer. By way of example, and not limitation, such non-transitory computer-readable storage media may comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that may be used to carry or store desired program code in the form of instructions or data structures and that may be accessed by a computer. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of non-transitory computer-readable storage media. Additionally, the operations of a method or algorithm may reside as one or any combination or set of codes and/or instructions on a machine readable medium and/or computer-readable medium, which may be incorporated into a computer program product. The preceding description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects without departing from the scope of the invention. Thus, the present invention is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

11857270

DETAILED DESCRIPTION Before turning to the figures, which illustrate the exemplary embodiments in detail, it should be understood that the application is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology is for the purpose of description only and should not be regarded as limiting. The present disclosure introduces a robotic assisted approach to support a revision procedure of a joint, such as the knee joint or the hip joint, by allowing precise removal of a primary implant with minimal bone loss and while reducing the time needed to remove the primary implant. When bone loss is minimized, the number of revision procedures that may be performed on an individual patient during their lifetime increases. Though the present disclosure makes reference to the knee and the hip joint, and revisions for the knee and the hip, the systems and methods disclosed herein are equally applicable to other orthopedic revision surgeries for other bones or joints, including, but not limited to, the shoulder, the wrist, the ankle, the spine, etc. The robotic-assisted surgery system of the present disclosure is designed to assist revision procedures to minimize the amount of bone removed and/or the damage on the bone. The robotic assisted surgery system is also designed to shorten the lengthy learning curve for the surgeon for performing a revision procedure. The robotic assisted surgery system may help in reducing the time to perform a revision, and allow a better recovery of the bone because the bone may be less “damaged” as a result of the use of the robotic system. In addition, the disclosure addresses one major issue of the previously used systems which is visibility of the progress of the breakdown of the interface. In certain embodiments, the robotic system can provide the user with a plan to remove the interface entirely, and then help the user execute the plan while providing feedback during the removal process. Exemplary Robotic System Various features of a robotic assisted surgery system and methods according to the present disclosure will now be described in greater detail.FIG.1provides a schematic diagram of an exemplary computer-assisted surgery (CAS) system100, in which processes and features associated with certain disclosed embodiments may be implemented. Surgical system100may be configured to perform a wide variety of orthopedic surgical procedures such as, for example, knee revision procedures. Surgical system100includes a tracking system101, computing system102, one or more display devices103a,103b, and a robotic system104. It should be appreciated that system100, as well as the methods and processes described herein, may be applicable to many different types of joint revision procedures. Although certain disclosed embodiments may be described with respect to knee revision procedures, the concepts and methods described herein may be applicable to other types of orthopedic surgeries, such as hip revisions, shoulder revision procedures, and other types of orthopedic procedures. Further, surgical system100may include additional elements or fewer elements than those described, to aid in surgery (e.g., surgical bed, etc.). Robotic system104can be used in an interactive manner by a surgeon to perform a surgical procedure, such as a revision procedure, on a patient. As shown inFIG.1, robotic system104includes a base105, an articulated arm106, a force system (not shown), and a controller (not shown). A surgical tool110(e.g., an end effector having an operating member, such as a saw, reamer, or burr) may be coupled to the articulated arm106. The surgeon can manipulate the surgical tool110by grasping and manually moving the articulated arm106and/or the surgical tool110. The force system and controller are configured to provide a cutting restraint guide via control or guidance to the surgeon during manipulation of the surgical tool. The force system is configured to provide at least some force to the surgical tool via the articulated arm106, and the controller is programmed to generate control signals for controlling the force system. In one embodiment, the force system includes actuators and a back-driveable transmission that provide haptic (or force) feedback to constrain or inhibit the surgeon from manually moving the surgical tool beyond predefined haptic boundaries defined by haptic objects as described, for example, in U.S. Pat. No. 8,010,180 and/or U.S. patent application Ser. No. 12/654,519 (U.S. Patent Application Pub. No. 2010/0170362), filed Dec. 22, 2009, each of which is hereby incorporated by reference herein in its entirety. The force system and controller may be housed within the robotic system104. In some embodiments, cutting restraint or guidance is provided though a handheld manipulator or handheld robotic device, such as described in U.S. Pat. No. 9,399,298 entitled “Apparatus and Method for Providing an Adjustable Positive Stop in Space,” U.S. Pat. No. 9,060,794 entitled “System and Method for Robotic Surgery,” and U.S. Patent Publication No. 2013/0060278 entitled “Surgical instrument including housing, a cutting accessory that extends from the housing and actuators that establish the position of the cutting accessory relative to the housing,” each of which is incorporated herein by reference in its entirety. Tracking system101is configured to determine a pose (i.e., position and orientation) of one or more objects during a surgical procedure to detect movement of the object(s). For example, the tracking system101may include a detection device that obtains a pose of an object with respect to a coordinate frame of reference of the detection device. As the object moves in the coordinate frame of reference, the detection device tracks the pose of the object to detect (or enables the surgical system100to determine) movement of the object. As a result, the computing system102can capture data in response to movement of the tracked object or objects. Tracked objects may include, for example, tools/instruments, patient anatomy, implants/prosthetic devices, and components of the surgical system100. Using pose data from the tracking system101, the surgical system100is also able to register (or map or associate) coordinates in one space to those in another to achieve spatial alignment or correspondence (e.g., using a coordinate transformation process as is well known). Objects in physical space may be registered to any suitable coordinate system, such as a coordinate system being used by a process running on a surgical controller and/or the computer device of the robotic system104. For example, utilizing pose data from the tracking system101, the surgical system100is able to associate the physical anatomy, such as the patient's tibia, with a representation of the anatomy (such as an image displayed on the display device103). Based on tracked object and registration data, the surgical system100may determine, for example, a spatial relationship between the image of the anatomy and the relevant anatomy. Registration may include any known registration technique, such as, for example, image-to-image registration (e.g., monomodal registration where images of the same type or modality, such as fluoroscopic images or MR images, are registered and/or multimodal registration where images of different types or modalities, such as MM and CT, are registered), image-to-physical space registration (e.g., image-to-patient registration where a digital data set of a patient's anatomy obtained by conventional imaging techniques is registered with the patient's actual anatomy), combined image-to-image and image-to-physical-space registration (e.g., registration of preoperative CT and MM images to an intraoperative scene), and/or registration using a video camera or ultrasound. The computing system102may also include a coordinate transform process for mapping (or transforming) coordinates in one space to those in another to achieve spatial alignment or correspondence. For example, the surgical system100may use the coordinate transform process to map positions of tracked objects (e.g., patient anatomy, etc.) into a coordinate system used by a process running on the computer of the haptic device and/or a surgical controller. As is well known, the coordinate transform process may include any suitable transformation technique, such as, for example, rigid-body transformation, non-rigid transformation, affine transformation, and the like. In some embodiments, the video camera includes a tracker and a scan of the bone to obtain a model and register the model. For example, an initial 3D model can be created and automatically registered. In some embodiments, the video camera can be used to register a 3D model corresponding to a CT scan. According to some embodiments, a video camera or ultrasound can be used for both initial model creation and registration. The tracking system101may be any tracking system that enables the surgical system100to continually determine (or track) a pose of the relevant anatomy of the patient. For example, the tracking system101may include a non-mechanical tracking system, a mechanical tracking system, or any combination of non-mechanical and mechanical tracking systems suitable for use in a surgical environment. The non-mechanical tracking system may include an optical (or visual), magnetic, radio, or acoustic tracking system. Such systems typically include a detection device adapted to locate in predefined coordinate space specially recognizable trackable elements (or trackers) that are detectable by the detection device and that are either configured to be attached to the object to be tracked or are an inherent part of the object to be tracked. For example, a trackable element may include an array of markers having a unique geometric arrangement and a known geometric relationship to the tracked object when the trackable element is attached to the tracked object. The known geometric relationship may be, for example, a predefined geometric relationship between the trackable element and an endpoint and axis of the tracked object. Thus, the detection device can recognize a particular tracked object, at least in part, from the geometry of the markers (if unique), an orientation of the axis, and a location of the endpoint within a frame of reference deduced from positions of the markers. The markers may include any known marker, such as, for example, extrinsic markers (or fiducials) and/or intrinsic features of the tracked object. Extrinsic markers are artificial objects that are attached to the patient (e.g., markers affixed to skin, markers implanted in bone, stereotactic frames, etc.) and are designed to be visible to and accurately detectable by the detection device. Intrinsic features are salient and accurately locatable portions of the tracked object that are sufficiently defined and identifiable to function as recognizable markers (e.g., landmarks, outlines of anatomical structure, shapes, colors, or any other sufficiently recognizable visual indicator). The markers may be located using any suitable detection method, such as, for example, optical, electromagnetic, radio, or acoustic methods as are well known. For example, an optical tracking system having a stationary stereo camera pair sensitive to infrared radiation may be used to track markers that emit infrared radiation either actively (such as a light emitting diode or LED) or passively (such as a spherical marker with a surface that reflects infrared radiation). Similarly, a magnetic tracking system may include a stationary field generator that emits a spatially varying magnetic field sensed by small coils integrated into the tracked object. Computing system102may be communicatively coupled to tracking system101and may be configured to receive tracking data from tracking system101. Based on the received tracking data, computing system102may determine the position and orientation associated with one or more registered features of the surgical environment, such as surgical tool110or portions of the patient's anatomy. Computing system102may also include surgical planning and surgical assistance software that may be used by a surgeon or surgical support staff during the surgical procedure. For example, during a joint replacement procedure, computing system102may display images related to the surgical procedure on one or both of the display devices103a,103b. Computing system102(and/or one or more constituent components of surgical system100) may include hardware and software for operation and control of the surgical system100. Such hardware and/or software is configured to enable the system100to perform the techniques described herein. FIG.2illustrates a block diagram of the computing system102according to an exemplary embodiment. The computing system102includes a surgical controller112, a display device103(e.g., display devices103aand103b), and an input device116. The surgical controller112may be any known computing system but is preferably a programmable, processor-based system. For example, the surgical controller112may include a microprocessor, a hard drive, random access memory (RAM), read only memory (ROM), input/output (I/O) circuitry, and any other known computer component. The surgical controller112is preferably adapted for use with various types of storage devices (persistent and removable), such as, for example, a portable drive, magnetic storage, solid state storage (e.g., a flash memory card), optical storage, and/or network/Internet storage. The surgical controller112may comprise one or more computers, including, for example, a personal computer or a workstation operating under a suitable operating system and may include a graphical user interface (GUI). Still referring toFIG.2, in an exemplary embodiment, the surgical controller112includes a processing circuit120having a processor122and memory124. Processor122can be implemented as a general purpose processor executing one or more computer programs to perform actions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit), a group of processing components, or other suitable electronic processing components. Generally, a processor will receive instructions and data from a read only memory or a random access memory or both. Memory124(e.g., memory, memory unit, storage device, etc.) comprises one or more devices (e.g., RAM, ROM, Flash-memory, hard disk storage, etc.) for storing data and/or computer code for completing or facilitating the various processes described in the present application. Memory124may be or include volatile memory or non-volatile memory. Memory124may include database components, object code components, script components, or any other type of information structure for supporting the various activities described in the present application. According to an exemplary embodiment, memory124is communicably connected to processor122and includes computer code for executing one or more processes described herein. The memory124may contain a variety of modules, each capable of storing data and/or computer code related to specific types of functions. In one embodiment, memory124contains several modules related to surgical procedures, such as a planning module124a, a navigation module124b, a registration module124c, and a robotic control module124d. Alternatively, or in addition, the program instructions can be encoded on an artificially generated propagated signal, e.g., a machine-generated electrical, optical, or electromagnetic signal, that is generated to encode information for transmission to suitable receiver apparatus for execution by a data processing apparatus. A computer storage medium can be, or be included in, a computer-readable storage device, a computer-readable storage substrate, a random or serial access memory array or device, or a combination of one or more of them. Moreover, while a computer storage medium is not a propagated signal, a computer storage medium can be a source or destination of computer program instructions encoded in an artificially generated propagated signal. The computer storage medium can also be, or be included in, one or more separate components or media (e.g., multiple CDs, disks, or other storage devices). Accordingly, the computer storage medium may be tangible and non-transitory. A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, declarative or procedural languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, object, or other unit suitable for use in a computing environment. A computer program may, but need not, correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto optical disks, or optical disks. However, a computer need not have such devices. Moreover, a computer can be embedded in another device, e.g., a mobile telephone, a tablet, a personal digital assistant (PDA), a mobile audio or video player, a game console, a Global Positioning System (GPS) receiver, or a portable storage device (e.g., a universal serial bus (USB) flash drive), to name just a few. Devices suitable for storing computer program instructions and data include all forms of non-volatile memory, media and memory devices, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto optical disks; and CD ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry. Embodiments of the subject matter described in this specification can be implemented in a computing system that includes a back end component, e.g., as a data server, or that includes a middleware component, e.g., an application server, or that includes a front end component, e.g., a client computer having a graphical user interface or a Web browser through which a user can interact with an embodiment of the subject matter described in this specification, or any combination of one or more such back end, middleware, or front end components. The components of the system can be interconnected by any form or medium of digital data communication, e.g., a communication network. Referring to the embodiment of surgical system100depicted inFIG.2, the surgical controller112further includes a communication interface130. The communication interface130of the computing system102is coupled to a computing device (not shown) of the robotic system104via an interface and to the tracking system101via an interface. The interfaces can include a physical interface and a software interface. The physical interface of the communication interface130can be or include wired or wireless interfaces (e.g., jacks, antennas, transmitters, receivers, transceivers, wire terminals, etc.) for conducting data communications with external sources via a direct connection or a network connection (e.g., an Internet connection, a LAN, WAN, or WLAN connection, etc.). The software interface may be resident on the surgical controller112, the computing device (not shown) of the robotic system104, and/or the tracking system101. In some embodiments, the surgical controller112and the computing device (not shown) are the same computing device. The software may also operate on a remote server, housed in the same building as the surgical system100, or at an external server site. Computing system102also includes display device103. The display device103is a visual interface between the computing system102and the user. The display device103is connected to the surgical controller112and may be any device suitable for displaying text, images, graphics, and/or other visual output. For example, the display device103may include a standard display screen, a touch screen, a wearable display (e.g., eyewear such as glasses or goggles), a projection display, a head-mounted display, a holographic display, and/or any other visual output device. The display device103may be disposed on or near the surgical controller112(e.g., on the cart as shown inFIG.1) or may be remote from the surgical controller112(e.g., mounted on a stand with the tracking system101). The display device103is preferably adjustable so that the user can position/reposition the display device103as needed during a surgical procedure. For example, the display device103may be disposed on an adjustable arm (not shown) or to any other location well-suited for ease of viewing by the user. As shown inFIG.1there may be more than one display device103in the surgical system100. The display device103may be used to display any information useful for a medical procedure, such as, for example, images of anatomy generated from an image data set obtained using conventional imaging techniques, graphical models (e.g., CAD models of implants, instruments, anatomy, etc.), graphical representations of a tracked object (e.g., anatomy, tools, implants, etc.), constraint data (e.g., axes, articular surfaces, etc.), representations of implant components, digital or video images, registration information, calibration information, patient data, user data, measurement data, software menus, selection buttons, status information, and the like. In addition to the display device103, the computing system102may include an acoustic device (not shown) for providing audible feedback to the user. The acoustic device is connected to the surgical controller112and may be any known device for producing sound. For example, the acoustic device may comprise speakers and a sound card, a motherboard with integrated audio support, and/or an external sound controller. In operation, the acoustic device may be adapted to convey information to the user. For example, the surgical controller112may be programmed to signal the acoustic device to produce a sound, such as a voice synthesized verbal indication “DONE,” to indicate that a step of a surgical procedure is complete. Similarly, the acoustic device may be used to alert the user to a sensitive condition, such as producing a tone to indicate that a surgical cutting tool is nearing a critical portion of soft tissue or is approaching a virtual control boundary. To provide for other interaction with a user, embodiments of the subject matter described in this specification can be implemented on a computer having input device116that enables the user to communicate with the surgical system100. The input device116is connected to the surgical controller112and may include any device enabling a user to provide input to a computer. For example, the input device116can be a known input device, such as a keyboard, a mouse, a trackball, a touch screen, a touch pad, voice recognition hardware, dials, switches, buttons, a trackable probe, a foot pedal, a remote control device, a scanner, a camera, a microphone, and/or a joystick. For example, input device116can allow the user manipulate a virtual control boundary. Other kinds of devices can be used to provide for interaction with a user as well, for example, feedback provided to the user can be any form of sensory feedback, e.g., visual feedback, auditory feedback, or tactile feedback, and input from the user can be received in any form, including acoustic, speech, or tactile input. In addition, a computer can interact with a user by sending documents to and receiving documents from a device that is used by the user, for example, by sending web pages to a web browser on a user's client device in response to requests received from the web browser. General surgical planning and navigation to carry out the exemplary methods described above, and including haptic control and feedback as described in connection with surgical system100, may be performed by a computerized surgical system such as that described in U.S. Pat. No. 8,010,180 “Haptic Guidance System and Method” to Quaid et al., which is incorporated herein by reference in its entirety. Virtual Objects for Robotic Assisted Surgery FIGS.3A-3Billustrate an example x-ray showing a femur (F), a tibia (T), a femoral implant302and a tibial implant306, according to an exemplary embodiment. While an x-ray image is shown inFIGS.3A and3B, other images can be acquired and used to generate bone models using any of a variety of imaging techniques (e.g., CT, MRI, ultrasound, video camera, etc.) As shown, the femoral implant302includes projections, such as a peg304extending into the femur F, and the tibial implant306includes, for example, a keel308. During implantation, cement is provided under flat portions of a baseplate of the tibial implant306and along flat surfaces of the femoral implant302. In some embodiments, the femoral implant302includes 5 flat portions, portion ab, portion bc, portion cd, portion de, and portion ef. In some embodiments, cement is located on some or all of the flat portions of the femoral implant302. During a revision surgery, the implants302and306must be cut around for removal, including the peg304and the keel308. However, over time, the keel308may have ingrowth with the tibia T that may cause bone pieces to break off during removal. To reduce the bone loss during removal, an image of the implant (e.g., obtained by CT, MRI, video, ultrasound, etc.), can be used to create a model of the bones and the implants for generation of surgical plans for removal. In some embodiments, a tracking probe can be used to probe, for example, areas near points a, b, c, d, e and f or along the edges of portions ab, bc, cd, de and ef to generate a model of the interface between the femoral implant302and the bone. FIG.4illustrates a graphical user interface showing a model of a bone402and a model of an implant404during a primary partial knee procedure, according to an exemplary embodiment. Specifically,FIG.4depicts a distal end of a femur402that received the femoral implant404. As shown, the femoral implant404includes elongated projections406(e.g., pegs, screws, keels, etc.) that were received by apertures in the femur. The elongated projections406further secure the femoral implant404to the bone402and help resist movement between the implant404and the bone402. The bone may have been prepared with keels (not shown), which interface with keels on the femoral implant404to improve security between the bone402and the implant404. The model may allow a user to modify the view of the implant model through rotation of the model or selection of different viewing modes. In some embodiments, the model may allow a user to view different cross sectional views of the implant, bone, or a combination thereof. In some embodiments, the model may also provide information to aid in planning a revision surgery (e.g., size, location, material, etc.). The surgical system100ofFIG.1may be configured to establish a virtual control object associated with the current prosthetic implant component and associated with or relative to one or more features of a patient's anatomy. The surgical system100may be configured to create a virtual representation of a surgical site that includes, for example, virtual representations of a patient's anatomy, a surgical instrument to be used during a surgical procedure, a probe tool for registering other objects within the surgical site, and any other object associated with a surgical site. In addition to physical objects, the surgical system100may be configured to generate virtual objects that exist in software and may be useful during the performance of a surgical procedure. For example, surgical system100may be configured to generate virtual boundaries or virtual control boundaries, that correspond to a surgeon's plan for preparing a bone, such as boundaries defining areas of the bone that the surgeon plans to cut, remove, or otherwise alter. In the case of a revision surgery, the virtual boundaries may correspond to a surgeon's plan for removing the cement and the necessary bone making up the interface between an implanted prosthetic component and the bone on which it is implanted. Alternatively, or additionally, surgical system100may define virtual objects that correspond to a desired path or course over which a portion of surgical tool110(e.g., end effector200) should navigate to perform a particular task. The surgical system100may also be configured to generate virtual objects or boundaries as part of a specific surgical plan. In some embodiments, the surgical plan is generated based on a database of implants where the surgical plans correspond to registered models of implants or bones. If an implant is known in the database, a surgical plan can be proposed to the user. The surgical plan may include which tools should be used, what access is needed to get around parts of the implant, virtual boundaries, etc. The proposed surgical plan may include virtual objects around keels and pegs, and may propose tool changes for cutting around these implant features. In some embodiments, the surgical plans are modifiable by the user including, but not limited to, the tools to be used, the access needed, the shape of the implant and the virtual boundaries. In some embodiments, a generic surgical plan can be automatically modified based on a model capture of the patient's anatomy or implant, or on the specific implant. Virtual boundaries and other virtual objects may define a point, line, or surface within a virtual coordinate space (typically defined relative to an anatomy of a patient) that serves as a boundary at which a constraint is provided to a surgical instrument when the tracked position of the surgical instrument interacts with the virtual boundary or object. In some embodiments, the constraint is provided through haptic or force feedback. For example, as the surgeon performs a bone cutting operation, a tracking system of the surgical system100tracks the location of the cutting tool and, in most cases, allows the surgeon to freely move the tool in the workspace. However, when the tool is in proximity to a virtual boundary (that has been registered to the anatomy of the patient), surgical system100controls the force feedback system to provide guidance that tends to constrain the surgeon from penetrating the virtual boundary with the cutting tool. For example, a virtual boundary may be associated with the geometry of a virtual model of a prosthetic implant, and the haptic guidance may comprise a force and/or torque that is mapped to the virtual boundary and experienced by the surgeon as resistance to constrain tool movement from penetrating the virtual boundary. Thus, the surgeon may feel as if the cutting tool has encountered a physical object, such as a wall. Accordingly, the force feedback system of the surgical system100communicates this information to the surgeon regarding the location of the tool relative to the virtual boundary, and provides physical force feedback to guide the cutting tool during the actual cutting process. In this manner, the virtual boundary functions as a virtual cutting guide. The force feedback system of the surgical system100may also be configured to limit the user's ability to manipulate the surgical tool. The robotic system or manual tools could be attached to the implant to measure an applied force for removal. Monitoring the position of the implant with respect to the bone and the force applied could give the surgeon an indication of the ease of removal. This may indicate additional cutting is required to minimize unintentional bone loss. In some embodiments, the virtual boundaries define autonomous cutting controls allowing a surgical robot to perform all or some of the steps of the surgical plan autonomously. In some embodiments, the virtual boundaries define a combination of autonomous and manual cutting boundaries. In some embodiments, when using autonomous cutting controls, feedback can be used to indicate contact is made with the implant (e.g., contact made with a peg when the tool is cutting along a flat interface surface) and the surgical plan or boundaries could be adjusted to avoid the portion of the implant based on the feedback. For example, this may be particularly useful where a shape of a keel is not known or identifiable prior to beginning cutting, so the original boundaries do not take the keel into account. A surgical plan or virtual boundaries could be modified based on detected differences in the surgical plan and/or virtual boundary and the keel. In some embodiments, the virtual boundaries correspond to haptic boundaries defining a haptic object. In some embodiments, the haptic boundary is configured to provide haptic feedback when the haptic boundary is encountered. The haptic boundary can result in haptic feedback that is tactile, audible, visual, olfactory (i.e., smell), or other mean of providing feedback. In some embodiments, the rendering application also creates a virtual object (not shown) that represents a pathway from a first position to a second position. For example, the virtual object may include a virtual guide wire (e.g., a line) defining a pathway from a first position (e.g., a position of a tool in physical space used with the surgical system100) to a second position that includes a target (e.g., a target object such as the virtual object). The virtual object may be activated so that movement of the tool is constrained along the pathway defined by the virtual object. The surgical system100may deactivate the object when the tool reaches the second position and activates the target object (e.g., the virtual object). The tool may be automatically placed in a control, such as haptic control, (or burring) mode when the objectis activated. In a preferred embodiment, the object may be deactivated to enable the tool to deviate from the pathway. Thus, the user can override the guidance associated with the object to deviate from the guide wire path and maneuver the tool around untracked objects (e.g., screws, retractors, lamps, etc.) that may not be accounted for when the virtual guide wire is generated. In the control mode, the robotic system104is configured to provide guidance to the user during a surgical activity such as bone preparation. In one embodiment, the rendering application may include the virtual object defining a cutting volume on the tibia T. The virtual object may have a shape that substantially corresponds to a shape of a surface of a tibial component such as when preparing for implantation. In revision surgery, the virtual object may have a shape that substantially corresponds to a shape of the interface between, for example, the tibial component and the tibia on which it is implanted or the path for bone removal to be followed. The robotic system104may enter the control mode automatically, for example, when the tip of the tool approaches a predefined point related to a feature of interest. In some embodiments, the tool can be disabled whenever the tool is outside the virtual object. In another embodiment, the tool can be disabled unless the robotic system104is generating control feedback forces. In operation, the surgical system100may be used for surgical planning and navigation. In addition to preparing a revision surgery, the surgical system100may be used, for example, to perform a knee replacement procedure or other joint replacement procedure involving installation of an implant. The implant may include any implant or prosthetic device, such as, for example, a total knee implant; a unicondylar knee implant; a modular knee implant; implants for other joints including hip, shoulder, elbow, wrist, ankle, and spine; and/or any other orthopedic and/or musculoskeletal implant, including implants of conventional materials and more exotic implants, such as orthobiologics, drug delivery implants, and cell delivery implants. Robotic Revision Surgery Revision surgery, such as knee revision, is a complex procedure and requires a very high level of expertise. There are several reasons that make the procedure more complex. The surgeon has to remove the original implant, which may be cemented or uncemented. The implant could have bone grown into it, and while removing the original implant, the surgeon has to try and conserve as much bone as possible. Furthermore, the implant(s) may include surfaces, keels, pegs, screws, or other components that need to be cut around, or through. In some embodiments, the implant may be multiple implants that individually need to be cut around and removed. Surgeons have to ensure that most of the bonds between the cement and the bone and/or between the implant and the bone are broken, resulting in a time consuming and complex process. Pre-existing solutions requires surgeons to chip away at the interface of bone-implant or bone-cement with manual or powered instruments. These include osteotomes, gigli saws and punches. Powered instrumentation is also available, for example power saws and burrs or ultrasonic devices. Despite attempts to preserve bone, there is always some amount of bone loss, and the surgeon must accurately fill in all the bone defects due to bone loss during removal of the implant. There may also be pre-existing bone defects that require attention after removal of the implant. The robotic system and specialized instrumentation of the present disclosure can help to resolve some of the issues faced during explantation. The need for a revision can include, for example, infections, misalignment, and wear. In knee revision due to infection, the surgery may be a two stage surgery. In the first stage, the infected implant is removed, and the wound is cleaned. A spacer block is added to the joint and the wound is closed. The second stage removes the spacer and adds the new revision implant. The present disclosure addresses the previously-faced issues of knee and/or hip revision by using a robotic-assisted approach. The present disclosure also describes a flexible end effector carrying a high-speed cutting burr. The flexible end effector is very dexterous to allow access to small areas such as the tibia posterior surface to remove the implant. Referring toFIGS.5A-5C, a flexible end effector200which may be used with the robotic arm106to perform a robotic assisted hip and knee revision procedure is shown, according to an exemplary embodiment. In some embodiments, the flexible end effector200may be an end effector according to any of the embodiments described in U.S. patent application Ser. No. 15/436,460, which is herein incorporated by reference in its entirety. Removing the implant manually can be difficult due to the limited access to the curtain bone area, such as a tibia posterior surface. The flexible end effector200is able to extend the robotic arm capability and allow access to those small areas. As shown inFIGS.5A and5B, the flexible end effector200includes two flexible bending elements202and204. Each element has two degrees of freedom and can be bent less or over 90 degrees in a three-dimensional space, as shown inFIG.5C. The end effector200may include a large internal channel to carry a flexible shaft. The flexible shaft is, for example, a hollow tube with a small wall thickness and is capable of spinning a cutting burr. In some embodiments, the hollow tube is capable of spinning the cutting burr at 60000 rpm. The flexible shaft's internal channel may also be used for an irrigation or suction channel. In some embodiments, the flexible elements202and204provide increased access for areas that are otherwise difficult to reach. The end effector200includes a housing206with a base208and a mount210. The base208secures the end effector200to the robotic arm106and provides stability to the end effector200. Mount210secures a shaft212of the end effector200. The shaft212houses a motor214that provides power to a cutting tool216located at a distal end of the end effector200. In some embodiments, the end effector200also includes a suction hole218. Suction hole218connects to the flexible shaft's internal channel. In some embodiments, the robotic arm106may be fixed and the end effector200may move autonomously to perform planned cuts, as described below. A variety of cutting tools216could be selected for the type of bone cut to be completed. A saw could be used for a planar cut, a burr for a curved surface, a curved saw may be used to obtain access around pegs, keels and/or screws (can be cut around or cut through and removed separately, or another cutting tool could be used that is better suited for the access to the bone and the type of cut to be created. A curved tool, or a tool capable of performing a curved cut is preferred for the critical posterior portions of the knee. In an exemplary embodiment, a saw could be used to perform initial cuts, and then more specific cuts could be performed using the specialized end effector200. In some embodiments, ultrasonic tools can be used to vibrate and break up bone cement for removal. In some embodiments, a laser can be used to melt cement. In some embodiments, a waterjet can be used to cut or break up cement. FIGS.6A-6Cillustrate various views of a femur F, a femoral implant302and another exemplary embodiment of an end effector200. End effector200inFIGS.6A-6Cmay include a base208, a mount210and a cutting tool216. The end effector200may be a vibratory chisel. In some embodiments, the cutting tool is capable of chipping and cutting away cement between bone and implant. The end effector200may be controlled and advanced by the surgeon, but may be constrained by a haptic boundary located between the bone and the implant to reduce skiving effect and ensure that all of the cement attachment would be accessed to preserve as much bone as possible. The end effector200may be used during the revision surgery to remove the implant by cutting along portions ab, bc, cd, de, and ef. The end effector can further by used to prepare the bone for a new implant. The bone may be prepared by creating surfaces ab, bc, cd, de, and ef in addition to a peg hole310for receiving peg304using cutting tool216or a variety of other cutting tools. FIGS.7A and7Bshow a femoral implant302after removal from a femur, when the removal is performed manually or without the use of a robotic system. As can be seen in the figures, in some revision surgeries, excess bone is removed when the implant302is removed, shown as bone312remaining on the implant302. When excess bone is removed, uneven surfaces314are created on the bone. Often, the excess bone removal occurs directly around a keel, peg or on the back side of the implant where it is difficult to cut the cement. In order to properly prepare the bone for a new implant, defects may need to be filled using augments, cones, or other filling methods. Video or ultrasound techniques may be used after removal of the implant to determine the characteristics of the remaining bone, to assist with correction of defects and planning re-implantation. The surgeon may execute the revision procedure using a robotic system to aid the surgeon in removal of the primary implant using various methods, described below. FIG.8is a flow chart of a method800of performing a revision surgery, according to an exemplary embodiment. Before beginning the procedure, information related to an interface area between an implanted implant component and the bone on which it is implanted must be obtained. This can be accomplished using images of the revision site or using other tools to understand the relationship other than by images. These variations for obtaining the interface information, depicted by optional steps802,804, and806inFIG.8, are described below. A first exemplary embodiment of the revision surgery method utilizes images of the patient's anatomy to plan the revision. When a patient's primary case (e.g., initial surgery) is performed by a robotic-assisted system, the bone model and implant information may already be available and there is no need to recapture images to perform a revision. At the time of the revision surgery, the patient's primary knee and hip bone model and implant information are available for the robotic assisted system, as depicted inFIG.4. In addition, models of the implant may be known and stored in a library of the surgical system for use during planning. In other cases, patient imaging data may not be available or it is desired to obtain new images. Accordingly, initial or new scans must be performed before planning and executing the revision procedure. In such embodiments, as shown by optional step802, the patient's anatomy is imaged using any preferred imaging modality, such as a CT or MRI scan, fluoroscopy, ultrasound, tracked markers, or by using a video camera. The images captured by the imaging device are used to create bone and implant models for use in the planning stages. (In some embodiments, in a case of a two stage revision, imaging can also be done after a spacer block is implanted. The spacer block may have features that will enable registration of the spacer block during the implantation surgery.) In some embodiments, a robotic device can be attached to an imagining device for intraoperative registration and tracking. The scan is then segmented or converted to bone models, at optional step804. The scan may be segmented in a predefined manner, or the surgeon may be able to select segmentation parameters. In some embodiments, when using a video camera, a 3D model can be created without segmentation. In some embodiments, a 3D model can be created using imaging, a statistical model, etc. As described above, registration of the images to the physical space/anatomy is executed by the surgical system100. In another exemplary embodiment, where image data is not captured on the patient's anatomy or is not used, the method may capture data intraoperatively with optional step806. In this step, the perimeter of the cement to bone or implant to bone interface is digitized using a tracked probe. Positional data of the tracked probe is captured by a tracking system, such as tracking system101to determine the location of the interface to be released. Digitizing the interface may also be performed in addition to models when image data, bone models, and/or implant models are available and/or used for the planning. The implant can then be registered to the primary bone model. In yet another embodiment, a camera or optical sensor may be coupled to the robotic arm to scan the implant surface and register it to the bone model. In another embodiment, a video camera can be moved around the patient to scan the bone and implant surface and create a 3D model. The surface of the implant can be probed to register the known implant location, or known features of the implant. In some embodiments, if the implant is known, probing can identify and register the implant with an implant model. Planning the implant removal cuts is performed at step808. In an embodiment where the image data is available from a pre-operative scan (whether it be recent scans or scans from the primary implantation surgery), the removal cuts may be based upon the images and the location of the interface between the cement and bone or the implant and bone. In some embodiments, a video camera is used to define planes and virtual boundaries. In some embodiments, a probe can be used to define planes and virtual boundaries. Alternatively, the removal cuts may be based on the intended replacement implant. In this way, the planned resection cuts may be planned to properly accommodate the new implant while also removing the current implant. In some embodiments, the planning software generates the bone preparation plan to achieve the right alignment for the patient, such as a proper alignment of the tibia and femur. According to some embodiments, the robotic system104helps the surgeon plan and execute the right alignment for the knee in 3D. The bone preparation plan may be carried out automatically by the planning software, or the surgeon can aid in creating the bone preparation plan. Using previous image data (x-ray, CT, MM, fluroscopic, video, etc.) and intra-operative landmarks, a visualization of ideal native anatomy can be constructed, such as joint line, etc. The system can use range of motion and soft tissue compliance as input to assist with planning the procedure, as well. In some embodiments, fiducials may be placed in the spacer block to speed registration for the re-implantation surgery. After implant removal, the robot or manual tools could be used to remove remaining cement. Hand held tracked probes or probe attachments to the robot arm could be used to identify remaining cement in a 3D model. The model can be used to create another robotic cutting path for cement removal. In other embodiments, planning the implant removal cuts at step808can be based on the data collected by the digitized probe. Typically, total knee arthroscopy implant designs can include several flat bone facing surfaces. During digitization, points on each side of the implant could be collected to identify the planar surfaces. Using the perimeter data, the robotic system calculates a plan to separate the interface of interest. Using a probe to collect points to define planes that can be used for virtual boundaries. Probing the transition areas of the implant (the points between two flat surfaces can help identify the virtual boundaries). Intra-operative imaging or the use of a video camera can create models of the bone defect after implant removal. Updates to the existing model can be made by probing the defect to indicate where there is additional bone loss. This defect model can be used in the revision implant planning to assure proper implant selection to cover the defect. The defect model indicates the need for additional augment devices required to fill the defect. After the revision implants are selected, virtual boundaries are created for cutting the bone for implant insertion. Once the models and defects are created, a new plan can be generated to implement the modification and additions that need to be made to bone due to bone loss to accommodate insertion of a new implant. As part of this planning step808, as described above, the surgical system100generates a control object, such as a haptic object. The control object may define virtual boundaries that correspond to the surgeon's plan for preparing a bone. In particular, for a revision procedure, the virtual boundary is associated with a portion of the interface area that the surgeon plans to cut, remove, or otherwise alter in order to remove the current implant from the bone. A revision virtual boundary is created around the at least a portion of the interface area to allow the surgeon to precisely cut the bonding area between the bone and implant. In preferred embodiments, the virtual boundary for revision is created adjacent to the implant surface to protect from overcutting the bone. In this way, the revision boundary will minimize the bone removed, will reduce the risk of tear off the bone, and could increase the number of potential additional revision procedures which could be operated on patient in his/her lifetime. The boundary may be a planar boundary to which the cutting tool will be constrained by the virtual boundary, or a contoured boundary of any shape. The boundary may be created automatically by the system based on that image and positional data received, or may be manually created based on user input. In other embodiments, the boundary may be customizable or adjustable, for example, a surgeon may choose to move the boundary closer or further away from the interface to accommodate the quality of the bone. Using the control objects defining the virtual boundaries, the robotic system can ensure that the cutting tool does not migrate outside of a desired cutting area, the minimal bone is removed, and that the cuts are executed accurately. If the implant is known, virtual boundaries can be identified with a proposed surgical plan. The proposed surgical plan can be used as a starting template for the surgeon that can be modified to fit specific needs and/or conditions of the operation. In some embodiments, the proposed plans are generic. In some embodiments, the proposed plans provide proposed tools and/or proposed access locations for preparing the bone for implant features, such as keels, pegs, or any other structures or shapes that need to be avoided. In some embodiments, a generic template of shapes can be used in the virtual boundary planning or custom shapes can be drawn, created or selected during the surgical planning. In particular, the surgical plan may need to be customized based on the characteristics of the remaining bone after the initial implant has been removed. In some embodiments, access locations and dimensions can be identified in the proposed surgical plan. In some embodiments, entry paths can be outlined in the proposed surgical plan. In some embodiments, the planning software can also determine the size and number of augments needed, at step810. The planning software may select an augmentation size based on a database of information. In another embodiment, the planning software allows the user to enter the size and number of augments needed. For example, a surgeon can tell the system, via the graphical user interface, to add a 5 mm posterior augment or a medial 20 deg tibia wedge, and the planning software allows for such cuts to be executing by a surgical tool coupled to the robotic arm, instead of thru jigs. Pre-operative augment sizing and planning, made possible by using a robotic system according to the exemplary embodiments disclosed herein, save valuable operating room time and make the procedure more efficient and precise. In step812, the robotic system104tracks movement of the cutting tool, using the navigation system101, and guides the surgeon while the planned cuts are performed. The system104can guide the execution of the cuts by providing a constraint on the cutting tool based on a relationship between the virtual tool (associated with the cutting tool) and the virtual boundary. The guide can be provided using haptics or the system can autonomously perform the cuts, based on the control objects generated by the system that correspond with the surgical plan. When haptics are used, the surgeon will receive feedback indicating when a haptic boundary is reached, preventing the surgeon from removing excessive bone. In some embodiments, the surgeon can use a combination of haptic control and autonomous action to perform the cuts. In some embodiments, the robotic system may also provide feedback related to the bone implant or bone cement breaking up process. For example, the robotic system may provide the surgeon with information on the progress of the cement bone or implant bone interface break. This may prevent any unintentional loss of bone while pulling out the implant if the interface is not yet properly broken. In some embodiments, the robotic system104may remove hardware thru impaction. The robotic system can use the force of robot arm to “jolt” implants loose or through use of the end effector acting like a wood pecker. Use of a robotic system allows for use of a variety of cutting tools, based on the type of bone cut to be completed. A saw could be used for a planar cut, a burr for a curved surface, a curved saw may be used to obtain access around pegs or keels, and/or access around or through screws or another cutting tool could be used that is better suited for the access to the bone and the type of cut to be created. The robotic system tracks the cutting tools and the patient to monitor the cutting procedure and provide the user with information on the progress of the cement bone or implant bone interface break. Again, this reduces unintentional loss of bone that may occur while pulling out the implant prior to properly releasing the interface. In some embodiments, a value, such as a percentage, of the surface resection can be displayed. This can give the surgeon an indication of the appropriate time to attempt implant removal. In some embodiments, if the surgeon is concerned about bone loss in a specific area, the display could show an amount of bone removal for a specific area of interest. In some embodiments, the surgeon can identify the specific area of interest to be calculated before or during surgery. Furthermore, the robotic system or manual tools could be attached to the implant to measure an applied force for removal. Monitoring the position of the implant with respect to the bone and the force applied could give the surgeon an indication of the ease of removal. This may indicate when additional cutting is required to minimize unintentional bone loss. After implant removal, if there are any bone defects that the planning software did not take into account, the bone defect may be digitized or identified by another means at optional step814. At step816, the planning software may generate the sizing information for filling the defect with various implant or biomaterial fillers. The implants and/or biomaterial fillers may be selected from a database of available implants or fillers. In some embodiments, the software can generate plans and create custom implants or fillers for filling the defect. In some embodiments, the software selects implants and/or biomaterial filler based on several factors (e.g., defect size, bone density, etc.). According to some embodiments, the robotic system104is able to determine the correct size of cones used to fill defects. In other embodiments, bone filler materials could be cut to the size of the defect, or the system could be configured to inject liquid fillers into the defect that could be solidified inside the patient. In step818, the planning software determines a desired pose of the replacement implant in the bone, and plans bone preparation for receiving the replacement implant. The planning may be carried out, and control objects created, in a similar manner as described in step808. There are several additional ways in which the robotic system can assist with a revision procedure, in addition to executing those steps discussed above. With respect to planning and preparing for implantation of a new implant component, the display device103may display limb alignment/balancing screens for an assessment of how implants are installed, which will help with planning the adjustment. Furthermore, the system may help assess stem length, straight vs. bowed, cemented vs. press-fit based on bone morphology, quality, and adjacent hardware, etc. The assessment may be patient specific or predictive from a pre-defined data set. In another embodiment, the robotic system may apply distraction through a leg holder, spread, balancer, etc. to assess and define collateral tension. This can be performed at a plurality of poses, and the graphical user interface or internal algorithm can be employed to calculate joint line placement and component sizes to best restore kinematics and function. In yet another embodiment, the robotic system may be used to assist in revision surgeries from partial knee, bicompartmental, or tricompartmental into cruciate retaining, cruciate substituting, or posterior stabilized. A video camera may also be used in step814to create a model of the bone after the implant has been removed. This identifies the current bone geometry without the implant, including any bone defects that require attention. The video camera and the images obtained therefrom can then be used in step818for planning the bone cuts, in step820(described below) for executing the bone cuts to prepare the bone for the replacement implant, and for placing the implant. In some embodiments, the video camera can be used during other phases of the procedure, such as for model creation, registration, or tracking the positions of the anatomy or the surgical tool(s) used during the procedure. In some embodiments, the model may also include identification of the incisions, either by selecting the edge in the system software, using color identification, image detection of retractors holding the incision open, or applying a material around the incision that can be detected by the camera. The video camera may then also be used to track the location of the incision during the procedure. In step820, the cuts for preparing the bone surface for placing augments, cones, fillers, and the final implant are executed. The surgeon can perform the bone preparation cuts using guidance from the system such as haptic feedback. In another embodiment, the robotic system104may autonomously perform the preparation cuts. As described above, the system can resect the bone for the new plan as a step to remove the existing hardware. Therefore, instead of sawing/chipping away at the existing implant, a resection is made that will help remove the implant but also be the proper cuts for the next implant. In some embodiments, the robotic system can be used in additional ways while performing cuts to the bone. For example, the system can assist with executing adaptive cuts where subsequent cuts are made may be based on a variety of possible inputs of prior cut data or other landmarks/objectives. For example, a probe may define the distal plane and posterior tangent for example and for a defined size implant make the rest of the cuts (femur or tibia or patella). The input can be an existing resection or a target articular tangency. The computed cuts can be programmed based on inputs to create a desired outcome. In addition, the system can be used for cut refinement. A surface is probed and then skim cut, (e.g., 0.5-1 mm cut). Control boundaries, such as haptics, can be updated or generated intra-operatively as the cuts are made. In another example, the robotic system104can control saw performance based on bone quality. Super soft/spongy bone or hard sclerotic bone might need a “lighter” or “harder” touch in speeds and/or feeds, or even different blades. The robotic system can also assist with placement of the implant and assessment after the implant has been replaced. For example, the display device showing a graphical user interface may be used to guide a surgeon on placement of the femoral or tibial components with stems, in terms of the offset or angled couplers or manipulating the anterior-posterior or medial-lateral position slightly to achieve less tip or cortical stress points. Furthermore, the robotic arm can be used to hold the implant in place relative to the bone while the cement is curing. In yet another embodiment, the system can help assess, via a range of motion/balancing graphical user interface, if the new construct is stable enough. In some embodiments, the robotic system104may visualize implant paths or cement areas when considering other aspects of surgery, for example when a tibia tuberosity is translated and the window of tibia sectioned and moved, where the hardware is, be it trauma plates, etc. relative to knee implants, etc. The construction and arrangement of the systems and methods as shown in the various exemplary embodiments are illustrative only. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, use of materials, colors, orientations, etc.). For example, the position of elements may be reversed or otherwise varied and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of the present disclosure. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present disclosure. The present disclosure contemplates methods, systems and program products on any machine-readable media for accomplishing various operations. The embodiments of the present disclosure may be implemented using existing computer processors, or by a special purpose computer processor for an appropriate system, incorporated for this or another purpose, or by a hardwired system. Embodiments within the scope of the present disclosure include program products comprising machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media can be any available media that can be accessed by a general purpose or special purpose computer or other machine with a processor. By way of example, such machine-readable media can comprise RAM, ROM, EPROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage, other magnetic storage devices, solid state storage devices, or any other medium which can be used to carry or store desired program code in the form of machine-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer or other machine with a processor. When information is transferred or provided over a network or another communications connection (either hardwired, wireless, or a combination of hardwired or wireless) to a machine, the machine properly views the connection as a machine-readable medium. Thus, any such connection is properly termed a machine-readable medium. Combinations of the above are also included within the scope of machine-readable media. Machine-executable instructions include, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing machines to perform a certain function or group of functions. Although a specific order of method steps may be described, the order of the steps may differ from what is described. Also, two or more steps may be performed concurrently or with partial concurrence. Such variation will depend on the software and hardware systems chosen and on designer choice. All such variations are within the scope of the disclosure. Likewise, software implementations could be accomplished with standard programming techniques with rule based logic and other logic to accomplish any connection steps, processing steps, comparison steps, and decision steps.

11857271

DETAILED DESCRIPTION Provided herein are devices, systems, and methods for a three-dimensional registering, tracking, and/or guiding an object of interest, such a body part, a surgical tool, or an implant, during a surgical procedure. Such devices, systems, and methods may offer minimally invasive, high precision registering, tracking, and/or guiding of the object of interest using a patterned light beam, including but not limited to a crosshair pattern, and data processing using artificial intelligence. The devices, systems, and methods disclosed herein may provide an accurate, real-time, three-dimensional surgical navigation for a system for robotic surgery or robotic-assisted surgery. This may improve the ability of the system for robotic surgery or robotic-assisted surgery to understand its operating room environment and the accuracy of the surgery performance. Such improvements may lead to shorter surgical time and better surgical outcome for the patient. Disclosed herein are methods, devices, and systems for three-dimensional registering, tracking, and/or guiding of the object of interest without using a marker. Alternatively, the methods, devices, and systems disclosed herein may be compatible with a simple marker or markers placed by a minimally invasive method on the object of interest. The ability to register, track, and/or guide without large markers, which sometimes are drilled into place at or near the object of interest in the patient and/or protrude out from their placement site, can be valuable. The methods, devices, and systems described herein for registering, tracking, and/or guiding without a marker or with a simple marker may avoid an invasive procedure to place the marker and damage to tissue at and around the object of interest. Usually, robot-assisted surgical systems rely on a marker-based tracking and a triangulation approach to track tools and body parts.FIG.1Bshows an example of protruding marker arrays drilled into a patient's leg in an invasive procedure to track the patient's leg, which can cause tissue damage at and near the drilled sites and extend the surgical procedure time. Such invasive fixation of markers to bones may lead to complications, infections, nerve injury, and bone fracture and may reduce the flexibility during the procedure. Accordingly, the methods, devices, and systems described herein may require shorter surgical time as the additional time to invasively place the large markers is not needed. Often, a shorter surgical procedure time may result in better surgical outcomes and less complications for the patient. Provided herein are methods, devices, and systems for minimally invasive, high precision, three-dimensional registering, tracking, and/or guiding of an object of interest during a surgical procedure to improve the performance of the surgery. The three-dimensional navigation based on the registering, tracking, and/or guidance may provide a real-time analysis of the body part to be operated on, such as the location, rotation, and orientation of bones of a joint in a total joint arthroplasty, which may aid the surgeon or healthcare professional in their performance of the surgery. The three-dimensional navigation may be used to make recommendations, guidance, and/or instruction on the surgical procedure, such as a location for making a cut on a body part or a choice of an implant or a device to use in the surgical procedure. The three-dimensional navigation may be used to provide recommendations or instructions to a robotic or robotic-assisted surgery system in performing the surgery. The three-dimensional navigation may provide a more accurate recommendation or instructions than by eye of the healthcare professional or without the navigation. As such, methods, devices, and systems provided herein may result in improvement performance of the surgery by the healthcare professional or a robotic system. The methods, devices, and systems described herein provide for registering and tracking an object of interest, such as a body part of a patient, and providing guidance to a surgeon or healthcare professional performing a surgical procedure during the surgical procedure. The devices and system may comprise a light source, an imaging module, and a processor having a software module and are interconnected to perform the methods described herein. Often, the methods, devices, and systems disclosed herein comprise steps of aiming a light beam from a light source at the object of interest, projecting the light beam onto a contour of the object of interest, obtaining an image of the light beam projected onto the contour of the object of interest using an imaging module, inputting data of the image into a software module for a processor, and analyzing the data of the image to determine at least one of orientation, rotation, and location of the object of interest in three-dimensional space using the software module. Usually, the light source, the imaging module, the processor, and the software module are interconnected and integrated into a system. Sometimes, the object of interest comprises more than one object, such as femur and tibia of a knee joint. Often, the light beam from the light source may pass through a patterned filter before being projected onto the object of interest. In some embodiments, the patterned filter has a patterned slit, and the resulting light beam has the pattern of the slit. In some embodiments, the pattern is a crosshair shape. In some embodiments, the patterned light beam provides a structured light that facilitates processing using artificial intelligence (AI) and machine learning (ML) for registering, tracking, and/or guiding. In some embodiments, the information of orientation, rotation, and/or location of the object of interest is used to provide guidance and recommendation to the surgeon or healthcare professional performing a surgical procedure. In some embodiments, the guidance and recommendation are displayed on a screen with a graphic user interface. In some embodiments, the guidance and recommendation comprise how to perform at least one surgical step in a surgical procedure. In some embodiments, the guidance and recommendation comprise displaying where to make cuts for an osteotomy or a joint replacement or resurfacing. In some embodiments, guidance and recommendation comprise which joint replacement or resurfacing implant to use based on the dimension of the implant or where and/or how to place the implant in the joint of the patient. In some embodiments, the object of interest is imaged and analyzed throughout the surgical procedure using the methods, devices, and systems described herein. Provided herein are methods, devices, and systems using AI and ML tracking and registering an object of interest and providing guidance to a surgeon during a surgical procedure. The methods, devices, and systems described herein comprise inputting data of an image comprising a light beam projected onto a contour of an object of interest into a software module using a processor; applying a convolution filter to the data of the image using the software module; quantizing the data of the image by dividing the data of the image into M bins using a comb mask having M teeth and selecting for pixel data above a threshold in the data divided into M bins using the software module; reconstructing a three-dimensional profile from the image using the software module; converting the three-dimensional profile to a two-dimensional profile using the software module; generating a feature vector by normalizing and concatenating the two-dimensional profile using the software module; and generating a pose vector by inputting the feature vector to a machine learning model, wherein the pose vector provides at least one of orientation, location, and rotation of the object of interest. In some case, the convolution filter comprises a set of convolution filters. In some cases, the convolution filter is applied to the image data to segment the image data into segments that are easier to analyze. In some cases, converting the three-dimensional profile to a two-dimensional profile comprises transforming the three-dimensional profile into a local coordinate system. In some cases, transformation into the local coordinate system reduces the dependency of the image data analysis on the location and orientation of the imaging module and allows for analysis irrespective of the location of the imaging module. In some cases, the pose vector is analyzed to provide guidance and recommendation for the surgeon or healthcare professional during the surgical procedure. Markerless Navigation Device and System The methods, devices, and systems provided herein comprise a light source, an imaging module, and a processor having a software module, and are interconnected and integrated to perform the methods described herein.FIG.2shows an example of an overview of the system comprising a light source having a patterned filter and a lens, a camera, and a processor having AI software for the navigation methods described herein. In some embodiments, navigation by the methods, devices, and systems provided herein comprises at least one of registering, tracking, and guiding the object of interest. In some embodiments, the object of interest comprises a body part of the patient or a surgical tool or instrument. In some embodiments, the object of interest comprises a joint of the patient. In some embodiments, the object of interest comprises the bones of the joint. In some embodiments, the surgical tool or instrument may be a part of a robotic surgical system. In some embodiments, registering comprises determining the position of the object of interest in comparison to a prior imaging or visualization of the object of interest. In some embodiments, prior imaging or visualization may include but is not limited to computer tomography (CT) scan, magnetic resonance imaging (MRI) scan, x-ray, positron emission tomography (PET), or ultrasound. In some embodiments, registering refers to relating one or more of the prior imaging or visualization to the location, orientation, and/or rotation of the object of interest generated by the methods, devices, system described herein. In some embodiments, the registration synchronizes the images and information obtained from various imaging modalities. The registration may facilitate the navigation of surgical instruments and tools by the robotic surgical system. In some embodiments, the registration facilitates recommendations of surgical steps provided by the methods, devices, and systems provided herein. In some embodiments, tracking refers to following the location, rotation, and/or orientation of a body part or a surgical tool during a surgical procedure. In some embodiments, tracking comprises following the relative location, rotation, and/or orientation of a surgical tool to a body part during a surgical procedure. Usually, the surgical tool that is tracked during a surgical procedure is a part of the robotic surgical system. In some embodiments, tracking provides real-time information of location, rotation, and/or orientation of the body part or the surgical tool during the surgical procedure. In some embodiments, location refers to a position of the object of interest in space. In some embodiments, location may be given in relation to an objective reference point. In some embodiments, orientation refers to relative position and/or direction of the object of interest. In some embodiments, orientation may be given in relation to a local coordinate to the object of interest. In some embodiments, rotation describes the movement of the object of interest about a point or an axis of rotation. In some embodiments, translation refers to movement of every point of the object of interest by the same distance in a given direction. Light Source Usually, the light source provides a light beam having a high-intensity radiance and a fixed wavelength. In some instances, the light source comprises a light-emitting diode (LED). In some instances, the light source comprises a laser. In some instances, the light source may be chosen based on light intensity or wavelength. In some instances, the light source emits a light beam at one wavelength. In some instances, the light source emits a light beam comprising at least two wavelengths. In some instances, the light source provides a light beam comprising wavelengths in the red, infrared, or green ranges. In some instances, the light source provides a light beam at least one of 530 nm (green), 625 nm (red), and 850 nm (infrared). In some instances, the light source provides a light beam having a wavelength in between about 900 nm to about 500 nm, about 900 nm to about 800 nm, about 700 nm to about 600 nm, or about 600 nm to about 500 nm. Often, the light beam provided the light source may pass through a lens. In some cases, the lens comprises an optical lens. In some cases, the lens comprises a patterned filter. In some cases, the patterned filter may shape the light beam to a particular pattern.FIG.3illustrates examples of lenses and patterns that can be used for the filter for the light source. In some cases, the filter pattern maybe at least one of a line, a grid, a cross, multiple lines, a half sphere, a thin line, a chessboard, a right angle, or a full sphere. In some cases, the filter pattern is a cross, also referred herein as crosshair. In some embodiments, the light beam is projected onto the object of interest. Usually, the light beam has a pattern that creates a unique projected pattern on the object of interest that can be used to identify the location, orientation, and/or rotation of the object. In some embodiments, the object of interest comprises at least two objects of interest that are tracked. In some embodiments, the object of interest comprises a plurality of objects of interest that are tracked. In some embodiments, the locations, orientations, and/or rotations of the plurality of objects can be tracked. Imaging Module The imaging module of the methods, devices, and systems provided herein is used to capture an image of the light beam projected onto the object of interest. In some instances, the imaging module comprise a camera. In some instances, the imaging module comprises a standard area scan camera. In some embodiments, the camera is a monochrome area scan camera. In some embodiments, the imaging module comprises a CMOS sensor. In some instances, the imaging module is selected for its pixel size, resolution, and/or speed. In some instances, pixel size and resolution affect the final tracking accuracy. In some instances, the camera speed (capturing and data transfer) determines the frame rate (latency). In some instances, the imaging module captures the images in compressed MPEG or uncompressed raw format. In some instances, the image comprises a data file in an image file format, including but not limited to JPEG, TIFF, or SVG. In some instances, the image comprises a data file in a video file format, including but not limited to MPEG or raw video format. In some instances, the image comprises video frames. In some instances, the imaging module is positioned and oriented at a different angle from the light source. In some instances, the imaging module is positioned and oriented to wholly capture the patterns projected on the object of interest. In some instances, the imaging module is configured to make the projected patterned light beam clearly visible and dim the rest of the environment, including the object.FIG.1Ashows an exemplary image of the crosshair-patterned projected light beam on the object captured by the imaging module. In some instances, images are captured by a standard area scan camera, which streams video frames in compressed MPEG or uncompressed raw format to a computer via an ethernet connection. In some instances, the captured image is transferred to a computer. In some instances, the image transfer to a computer occurs by an ethernet connection. In some instances, the image transfer to a computer occurs wirelessly, including but not limited to Wi-Fi or Bluetooth. In some instances, the power is supplied via Power-over-Ethernet protocol (PoE). The imaging module may need to be calibrated prior to use. In some embodiments, the imaging module may be calibrated so that the imaging module is configured for use with complex light beam patterns. Some calibration methods generally work with a line, stripes or a grid and are not compatible with more complex patterns. Various methods of calibrating laser scanning systems often may rely on scanning a known object and recovering the relative poses of both the laser (e.g. light source) and the camera (e.g. imaging module). In some cases, scanning objects may require a conveyor system, which may be error-prone and time consuming. The calibration method may allow for a highly accurate, simpler, and easier to implement calibration approach. Image Processing Workflow The image taken by the imaging module may be inputted into a computer comprising a software module and a processor.FIG.4illustrates an exemplary workflow of image data processing, where the system takes the images from the imaging module as an input and outputs the orientations and locations of the objects within the image. The input image may be segmented into at least two images, one for each leg of the crosshair, referred herein as U and V image. The segmented U and V images may be quantized by sampling bright pixels in the images. The quantized images may be converted to three-dimensional lines by using triangulation techniques. The three-dimensional points may be transformed into local coordinate systems of light sheets from the crosshair patterned light beam to obtain a two-dimensional point cloud. These two-dimensional point cloud points may be concatenated to form a feature vector, which can be input into a pose predictor. The pose predictor can predict a pose vector, representing location, rotations, and/or translations of the object of interest. The object of interest may be visualized in its current state. In some embodiments, when the light beam has a crosshair-pattern, the two legs of the crosshair may be referred to as “U” and “V” and the 2 planes defined by the light sheets as U plane and V plane respectively. In some embodiments, the intersection of the two planes is referred herein as the central ray, which shown in yellow or light gray inFIG.5. In some embodiments, in the context of knee joint tracking, the U line may span the femur and the tibia in near vertical directions and the V line may cut either femur or tibia horizontally as shown inFIG.5. Image Segmentation Usually, the image may be segmented to capture the salient features of the unique pattern of the projected light beam on the object of interest. In some embodiments, the image may be segmented to simplify the image and to make the image data easier to analyze in subsequent steps. An exemplary workflow for image segmentation by convolution is shown inFIG.6. In an image segmentation workflow, the images may be preprocessed by thresholding followed by blurring. In some cases, the image may be segmented by convolving it with at least one set of convolution filters. In some cases, the image may be segmented by convolving it with multiple sets of convolution filters at different stages of the workflow. In some embodiments, the convolution filters are two-dimensional filters. In some embodiments, the convolution filters are a set (N) of D×D×1 filters. In some embodiments, the image may be segmented by partitioning the image into different groups focused on different features of the image, including but not limited to the features that help identify an object in the image or boundaries of the object in the image. In some embodiments, the image may be segmented into a plurality of images. In some embodiments, the image may be segmented into at least two images. In some embodiments, the input image having a crosshair pattern may be segmented into two images, each image corresponding to one of the legs of the crosshair. In some embodiments, the segmented images corresponding to each leg of the crosshair are referred to as U and V images. In some embodiments, the segmentation uses a threshold-based approach using a single threshold or multiple thresholds. In some embodiments, the segmentation uses an edge-based approach to detect the edges in the input image. In some embodiments, the segmentation uses a region-based approach to detect region boundaries in the input image. In some embodiments, one of the segmentation algorithms, as shown inFIGS.7A and7B, may be used. As shown inFIG.7A, a convolutional architecture similar to that of a standard convolutional neural network (CNN) may be used to segment the image. In some embodiments, the image may be convolved with a first set (N) of first two-dimensional D×D×1 convolution filters, producing N filtered images. In some embodiments, the N filtered images are then convolved with one D×D×N filter to merge the N filtered images together to produce an intermediate filtered image. This process is performed for each segmented image that is generated. In some embodiments, the process described inFIG.7Ais repeated for U and V image separately for the image of the crosshair patterned light beam projected on to the object of interest. In some embodiments, the intermediate filtered images are concatenated to form an image with two channels. The intermediate filtered images are also referred herein as first merged images. In some embodiments, the merged image is convolved with a subsequent set of N second convolution filters having a dimension of D×D×2 and followed by a D×D×N filter in a second stage. In some embodiments, the weights of the filters are learned in a supervised manner with a dataset of input and output images. In some embodiments, the workflow undergoes training using a training dataset of input and output images to calculate the weights of the filters. In some embodiments, multiple convolution layers are applied to the image. In some embodiments, the first set of convolution filters and the subsequent set of convolutions filters may have the same dimensions or different dimensions. FIG.7Bshows a segmentation algorithm using a convolutional architecture. In some embodiments, the image may be convolved with a first set (N) of two-dimensional D×D×1 filters to produce N filtered images. In some embodiments, the filtered images may be averaged piecewise to produce the filtered image. In some embodiments, the filtered image comprises the segmented image. This process is performed for each segmented image that is generated. In some embodiments, the process described inFIG.7Bis repeated for U and V image separately for the image of the crosshair patterned light beam projected on to the object of interest. The segmentation algorithm as shown inFIG.7Bproduces two intermediate filtered images. The intermediate filtered images are also referred herein as first merged images. In some embodiments, the intermediate filtered images are concatenated to form an image with two channels. In some embodiments, the merged image is convolved with a subsequent set of N D×D×2 filters and followed by a D×D×N filter in a second stage. In some embodiments, multiple convolution layers are applied to the image. In some embodiments, the first set of convolution filters and the subsequent set of convolutions filters may have the same dimensions or different dimensions. The convolution filters used for methods and systems described herein and as shown inFIGS.7A and7Bmay have a variety of dimensions. In some embodiments, D is determined by the thickness of the projected light beam in the image. In some embodiments, D is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. In some embodiments, D is at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. In some embodiments, D is at no more than 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. In some embodiments, N is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100. In some embodiments, D is 5. In some embodiments, N is at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100. In some embodiments, N is no more than 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100. In some embodiments, the parameters of the filter are learned in a supervised manner. In some embodiments, the training dataset may be built by collecting a small number of image frames containing the light beam pattern of interest, such as the crosshair pattern, at various poses of object of interest. In some embodiments, the training dataset may be built by collecting a small number of image frames containing the crosshair light beam at various poses of the femur and tibia or various bones of a joint. In some embodiments, the original image may be segmented using an image editing software. In some embodiments, the segmented images comprise U and V images that are segmented using an image editing software. In some embodiments, pairs of input-output data (input_image, output_u, output_v) are used to train the filters in a supervised fashion. In some embodiments, the training is performed using automatic differentiation and adaptive optimization approaches. In some embodiments, Tensorflow 2.0 with Adam optimizer may be used to train the filters using the training dataset. Image Quantitation and Three-Dimensional Reconstruction The segmented images from the original image may be quantized and converted into a three-dimensional profile to prepare the image data for further processing to determine location, orientation, and/rotation information of the object of interest. In some embodiments, the image is quantized to compress the image in size. The smaller image file size facilitates faster processing and easier handling of the image by the processor. In some embodiments, each of the segmented images is quantized and converted to a three-dimensional profile. In some embodiments, some of the segmented image are quantized and converted to a three-dimensional profile. Sometimes, quantization comprises applying a comb mask to the segmented image to divide up image into sections, selecting for bright pixels above a threshold within a divided segmented image section, and averaging the bright pixel clusters in the section. In some embodiments, the segmented images are quantized by applying a bitwise operator on the segmented image and a template image. The resulting quantized image comprises one or more pixel clusters. In some embodiments, the resulting quantized image comprises a plurality of pixel clusters. In some embodiments, the mean of each pixel cluster is calculated to generate a list of two-dimensional image points. In some embodiments, the list of two-dimensional image points can be converted to three-dimensional points. In some embodiments, a triangulation technique is used to convert the two-dimensional image points to three-dimensional points. In some embodiments, the segmented U and V images are quantized by applying a bitwise AND operator on the segmented U and V images and a template image. In some embodiments, the template image comprises a comb mask. In some embodiments, the comb mask is generated by projecting a three-dimensional comb in the image plane. In some embodiments, the comb mask is generated beforehand the quantization step. In some embodiments, the comb mask comprises a plurality of teeth. In some embodiments, the teeth of the comb mask are chosen to be reasonably large to cover the variations of the light beam pattern projected on to the object of interest. In some embodiments, the teeth of the comb mask may be reasonably large to cover the variations of the crosshair-patterned light beam projected on to the object of interest. In some embodiments, the comb mask comprises at least 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, or 500 teeth. In some embodiments, the comb mask comprises no more than 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, or 500 teeth. In some embodiments, the comb mask comprises 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, or 500 teeth. In some embodiments, the bitwise operator comprises at least one of a bitwise AND operator, bitwise OR operator, bitwise NOT operator, bitwise XOR operator, bitwise complement operator, bitwise shift left operator, or bitwise shift right operator. In some embodiments, the bitwise operator comprises bitwise AND operator. In some embodiments, the bitwise AND operator selects for bright pixels that belong to a comb mask section, where the bright pixels have values above a threshold. In some embodiments, the comb mask section may coincide with a light plane, also referred herein as a light sheet. In some embodiments, the comb mask section refers to a section of the segmented image divided by the teeth of the comb mask. In some embodiments, the comb mask section is also referred to as regular comb. In some embodiments, the bitwise AND operator selecting for bright pixels in the comb section results in a quantized version of the segmented image. In some embodiments, the threshold is predetermined. In some embodiments, the threshold is adjusted for each individual image. In some embodiments, the threshold is a percentage of the brightest pixel in the image. In some embodiments, the threshold is at least about 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% of the brightest pixel in the image. In some embodiments, the threshold is no more than about 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% of the brightest pixel in the image. In some embodiments, the threshold is 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% of the brightest pixel in the image. FIG.8shows an exemplary workflow for image quantization. The workflow starts with generating a comb mask by projecting a three-dimensional comb on the image plane, shown as green vertical lines along the femur and tibia of a joint inFIG.8. The workflow comprises taking the segmented U image, applying a template image, which is shown as a U comb mask inFIG.8, and applying AND operator to select the bright pixels that belong to a regular comb, which coincides with a light plane. This results in a quantized version of the segmented image comprising multiple pixel clusters. Usually, the mean of each pixel cluster may be calculated to generate a list of two-dimensional image points. A triangulation technique may be used to convert the two-dimensional image points to three-dimensional points.FIG.9shows an example of the standard triangulation technique that may be used to convert the two-dimensional image points to three-dimensional points. Converting Three-Dimensional Profiles to Two-Dimensional Profiles The reconstructed three-dimensional points, also referred herein as a three-dimensional profile, may be converted to a two-dimensional profile by transforming the reconstructed three-dimensional points to a local coordinate system. The transformation of the three-dimensional points to a local coordinate system can remove the dependency of the reconstructed three-dimensional points on the location and orientation of the imaging module. In some embodiments, the transformation allows for the imaging module to be flexible and not fixed to an operating room or a location. In some embodiments, the transformation allows for the imaging module to be repositioned during a surgical procedure or in between procedures and still allow the images taken after repositioning to be compared to the images taken prior to repositioning of the imaging module. In some embodiments, the transformation to a local coordinate system allows for image data taken at different times by the imaging module that was repositioned to be compared to each other. In some embodiments, the reconstructed three-dimensional profile is converted to a two-dimensional profile by transforming them to a local coordinate system. In some embodiments, the conversion is performed for all of the three-dimensional profiles generated from quantization and three-dimensional reconstruction. In some embodiments, the conversion is performed for some of the three-dimensional profiles generated from quantization and three-dimensional reconstruction. In some embodiments, the local coordinate system is determined by the corresponding light sheets, also referred herein as light planes formed by the light beam projected on to the object of interest. In some embodiments, the local coordinate system is set in spatial relation to the light beam projected on to the object of interest. In some embodiments, the local coordinate system is set such that each of the two-dimensional profiles are connected to each other. The left panel A ofFIG.10shows an exemplary image of the patterned light beam projected onto a knee joint. The middle panel B ofFIG.10shows a local coordinate system determined by the V light sheet, shown by a dashed triangle. In some embodiments, the local coordinate system is defined by 3 basis vectors, Ox, Oy and Oz. In some embodiments, Oz coincides with the central ray, or the intersection of two light sheets. In some embodiments, Oy belongs to the V plane, defined by V light sheet, and is perpendicular to Oz. In some embodiments, Ox is orthogonal to the Oxy plane and belongs to the U plane that is defined by U light sheet. In some embodiments, the exact location of O is chosen according to the actual setup. In some embodiments, the exact location of O may be a point on a physical surface, including but not limited to a table top, an operating table, or a fixed object. The right panel C ofFIG.10shows exemplary two-dimensional profiles. Forming Feature Vector from Two-Dimensional Profiles Usually, the transformed two-dimensional profiles using local coordinate systems are normalized and concatenated to form a single feature vector. In some embodiments, each of the transformed two-dimensional profiles are normalized and concatenated. In some embodiments, concatenation converts the two-dimensional profiles into a single one-dimensional vector, also referred to as a string vector. In some embodiments, the concatenation reduces the dimension of the image data to facilitate the downstream processing steps. In some embodiments, the feature vector may be used as input to machine learning models in downstream steps. In some embodiments, the normalization of the concatenation of the two-dimensional profiles facilitates handling of the feature vector f by the downstream machine learning steps. In some embodiments, the transformed two-dimensional profiles may be written as ordered sets of y and z coordinates Cuand Cvas follows: Cu={uyi, uzi}, Cv={vyi, vzi}, i∈[1, N], where N is the number of teeth in the comb mask from segmentation step. In some embodiments, the two-dimensional profiles comprise U and V two-dimensional profiles. In some embodiments, the feature vector may be formed by dropping the y-coordinates and concatenating Cu, Cvand normalizing the concatenated vector as follows: f=[uz1, . . . , uzN, vz1, . . . , vzN]/λ, where λ is a normalizing constant. In some embodiments, the values in vector f is normalized to the [0, 1] range. In some embodiments, λ is the highest value in the two-dimensional profiles. In some embodiments, λ is at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 times the highest value in the two-dimensional profiles. In some embodiments, λ is a normalizing vector. In some embodiments, λ vector has the same length as the feature vector. Predicting Object Poses with Machine Learning The feature vector f may be input into a machine learning (ML) model that outputs a pose vector of the object of interest. The pose vector comprises information about the object of interest, including but not limited to position, location, rotation, and/or orientation of the object of interest. In some embodiments, the machine learning model (ML Model) takes the feature vector f as input and outputs the pose vector of the object of interest. In some embodiments, the pose vector comprises information on rotations and locations of the bones of a joint. In some embodiments, the pose vector represents rotations and locations of the femur and the tibia in the context of knee joint tracking. In some embodiments, the pose vector comprises a 14-element vector to represent the poses of the bones with a portion of the vector comprising information on rotation and location of each bone. In some embodiments, the pose vector comprises a 14-element vector to represent the poses of the femur and the tibia as follows: P=[qfx, qfy, qfz, qfw, lfx, lfy, lfz, qtx, qty, qtz, qtw, ltx, lty, ltz], where qf=[qfx, qfy, qfz, qfw] is femoral rotations in quaternion representation, l=[lfx, lfy, lfz] is the normalized location of femur, qt=[qtx, qty, qtz, qtw] is tibial rotations in quaternion representation, and l=[ltx, lty, ltz] is the normalized location of tibia. In some embodiments, the relationship between the feature vector f and pose vector P may be described as P=G(f), where G comprises a neural network for pose prediction. In some embodiments, the neural network for pose prediction comprises an one-dimensional convolutional neural network having additional fully connected layers for regression of the pose vector. In some embodiments, the neural network for pose prediction comprises a multilayer perceptron. In some embodiments,FIGS.12A and12Bprovide an exemplary architecture of a neural network for pose prediction. The design of the network may follow best practices such as interleaving convolution layers with max-pooling layers to simplify network complexity and improve robustness. In some embodiments, two convolution layers are followed by a max-pooling layer as shown inFIGS.12A and12B. In some embodiments, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 convolution layers are followed by a max-pooling layer. In some embodiments, at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 convolution layers are followed by a max-pooling layer. In some embodiments, no more than 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 convolution layers are followed by a max-pooling layer. In some embodiments, each subsequent layer has a higher number of filters than previous layer to account for different characteristics of the data at different scales. In some embodiments, the number of filters increases by a factor of 2. In some embodiments, techniques including but not limited to dilational convolution, strided convolution, or depth-wise convocation may be used to further improve performance and latency. In some embodiments, the pose vector of the object of interest may be used to provide a three-dimensional visual representation of the object of interest on a display. In some embodiments, initial location and rotation of the object of interest may be taken from the output of the machine learning model. In some embodiments, the poses of the bones may be refined further by applying a point cloud fitting method. In some embodiments, the point cloud fitting method comprises such an iterative closest point (ICP) algorithm. In some embodiments, the point cloud fitting method is applied to register the light beam pattern point cloud on a three-dimensional model of the object of interest. In some embodiments, the ICP algorithm may be applied to register the crosshair point cloud and a three-dimensional model of the corresponding bones as shown inFIG.11. In some embodiments, the three-dimensional model of the object of interest comprises a computer-aided design (CAD) model. In some embodiments, the application of the point cloud fitting method results in full registration of the light beam pattern and the object of interest together. In some embodiments, the application of the ICP algorithm results in full registration of the crosshair and the bones together. In some embodiments, the pose vector of the object of interest may be used to provide a three-dimensional visual representation of the object of interest on a display. In some embodiments, the visual representation of the object of interest may be manipulated by a user, such as rotating, zooming in, or moving the visual representation. In some embodiments, the visual representation of the object of interest may have recommendations on steps of the surgical procedure. In some embodiments, the recommendation comprises location and orientation of a cut to make on a bone for an arthroplasty or an orthopedic procedure. The ML algorithm for pose prediction may be trained. In some embodiments, the ML algorithm for pose prediction is trained with a training dataset. In some embodiments, a synthetic training dataset is used to train the pose prediction neural network. In some embodiments, the ML algorithm for pose prediction is trained with an experimental dataset or a real dataset. In some embodiments, the images of light beam pattern, such as the crosshair pattern, may be generated using software such as Blender and Unity. In some embodiments, ground-truth pose vectors may be used to train the neural network. In some embodiments, data augmentation may be used to simulate real-world distortions and noises. In some embodiments, a training set comprising augmented data simulating distortion and noises is used to train the pose prediction neural network. In some embodiments, the pose prediction neural network is trained using automatic differentiation and adaptive optimization. In some embodiments, Tensorflow 2.0 with Adam optimizer may be used to train the pose prediction neural network. FIG.13shows an exemplary embodiment of a method1300for markerless tracking and registering an object of interest. In step1302, a light beam is projected onto a contour of an object of interest. In step1304, an image of the light beam projected onto the contour of the object is obtained using an imaging module. In step1306, the image is input into a software module for a processor. In step1308, the image is segmented by applying convolution filters into segmented images. In step1310, the segmented images are quantized and 3D profiles are reconstructed from the quantized images. In step1312, the reconstructed 3D profiles are converted to 2D profiles by transformation to a local coordinate system. In step1314, a feature vector is formed from the 2D profiles by concatenation and normalization. In step1316, object poses are predicted by applying machine learning to the feature vector. In some embodiments, the computer program is further configured to cause the processor to identify the location, orientation, and/or rotation of the object of interest within the image. In some embodiments, the orientation and/or rotation of the object of interest is expressed as an angle. In some embodiments, the location, orientation, and/or rotation of the object of interest frame is expressed as a distance, a ratio, a code, or a function. In some embodiments, the imaging module captures the object of interest within the frame. In some embodiments, the object of interest comprises a joint of an individual. In some embodiments, the joint comprises at least one of a knee joint, a hip joint, an ankle joint, a hand joint, an elbow joint, a wrist joint, an axillary articulation, a stemoclavicular joint, a vertebral articulation, a temporomandibular joint, and articulations of a foot. In some embodiments, the joint comprises at least one of joint of a shoulder, elbow, hip, knee, or ankle. In some embodiments, the surgical procedure includes but is not limited to osteotomy, joint arthroplasty, total joint replacement, partial joint replacement, joint resurfacing, joint reconstruction, joint arthroscopy, joint replacement revision, meniscectomy, repair of a bone fracture, tissue grafting, and laminectomy. In some embodiments, the surgical procedure comprises repair of a ligament in a joint. In some embodiments, the surgical procedure comprises anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) repair. In some embodiments, the surgical procedure comprises a knee or a hip replacement. In some embodiments, the methods, devices, and systems provided herein provides guidance or recommendation on various steps in the surgical procedure, including but not limited to where the cut a bone, where to place a joint replacement prothesis or graft, and determine the effectiveness of the placement of the prothesis or graft. In some embodiments, the guidance provided by the methods, devices, and systems provided herein improves the accuracy of the surgical procedure step. In some embodiments, the guidance provided by the methods, devices, and systems provided herein improves the accuracy of the surgical procedure step by at least 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%. In some embodiments, the guidance provided by the methods, devices, and systems provided herein improves the accuracy of bone cutting by at least 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%. In some embodiments, accuracy of the procedure is measured by deviation of at least one of location, rotation, or orientation of the body part before the surgical step and the after performing the guided or recommended step in the procedure. In some embodiments, the methods provided herein are repeated throughout the surgical procedure to obtain information on location, rotation, and/or orientation of the object of interest during the surgical procedure. In some embodiments, the methods described herein provide a real-time or near real-time information on location, rotation, and/or orientation of the object of interest during the surgical procedure. In some embodiments, the methods described herein provide a real-time or near real-time tracking of the object of interest during the surgical procedure. In some embodiments, the methods provided herein are performed continuously during the surgical procedure. In some embodiments, the methods, devices, and systems described herein may be used with multiple light beams. In some embodiments, the methods, devices, and systems described herein may be used with multiple crosshair-patterned light beams. In some embodiments, the use of multiple light beam patterns allows the methods, devices, and systems provided herein to expand the field of view and analyze a larger field of view. In some embodiments, minimally invasive surface markers may be used alternatively or in combination with the patterned light beam for the methods, devices, and systems described herein. In some embodiments, minimally invasive surface markers may be used similarly to the pattern from the light beam by the methods, devices, and systems described herein. Processor The methods, devices, and systems provided herein comprises a processor to control and integrate the function of the various components to register, track, and/or guide the object of interest. Provided herein are computer-implemented systems comprising: a digital processing device comprising: at least one processor, an operating system configured to perform executable instructions, a memory, and a computer program. The methods, devices, and systems disclosed herein are performed using a computing platform. A computing platform may be equipped with user input and output features. A computing platform typically comprises known components such as a processor, an operating system, system memory, memory storage devices, input-output controllers, input-output devices, and display devices. In some instances, a computing platform comprises a non-transitory computer-readable medium having instructions or computer code thereon for performing various computer-implemented operations. FIG.14shows an exemplary embodiment of a system as described herein comprising a device such as a digital processing device1401. The digital processing device1401includes a software application configured to monitor the physical parameters of an individual. The digital processing device1401may include a processing unit1405. In some embodiments, the processing unit may be a central processing unit (“CPU,” also “processor” and “computer processor” herein) having a single-core or multi-core processor, or a plurality of processors for parallel processing or a graphics processing unit (“GPU”). In some embodiments, the GPU is embedded in a CPU die. The digital processing device1401also includes either memory or a memory location1410(e.g., random-access memory, read-only memory, flash memory), electronic storage unit1415(e.g., hard disk), communication interface1420(e.g., network adapter, network interface) for communicating with one or more other systems, and peripheral devices, such as a cache. The peripheral devices can include storage device(s) or storage medium(s)1465which communicate with the rest of the device via a storage interface1470. The memory1410, storage unit1415, interface1420and peripheral devices are configured to communicate with the CPU1405through a communication bus1425, such as a motherboard. The digital processing device1401can be operatively coupled to a computer network (“network”)1430with the aid of the communication interface1420. The network1430can comprise the Internet. The network1430can be a telecommunication and/or data network. The digital processing device1401includes input device(s)1445to receive information from a user, the input device(s) in communication with other elements of the device via an input interface1450. The digital processing device1401can include output device(s)1455that communicates to other elements of the device via an output interface1460. The CPU1405is configured to execute machine-readable instructions embodied in a software application or module. The instructions may be stored in a memory location, such as the memory1410. The memory1410may include various components (e.g., machine readable media) including, by way of non-limiting examples, a random-access memory (“RAM”) component (e.g., a static RAM “SRAM”, a dynamic RAM “DRAM, etc.), or a read-only (ROM) component. The memory1410can also include a basic input/output system (BIOS), including basic routines that help to transfer information between elements within the digital processing device, such as during device start-up, may be stored in the memory1410. The storage unit1415can be configured to store files, such as image files and parameter data. The storage unit1415can also be used to store operating system, application programs, and the like. Optionally, storage unit1415may be removably interfaced with the digital processing device (e.g., via an external port connector (not shown)) and/or via a storage unit interface. Software may reside, completely or partially, within a computer-readable storage medium within or outside of the storage unit1415. In another example, software may reside, completely or partially, within processor(s)1405. Information and data can be displayed to a user through a display1435. The display is connected to the bus1425via an interface1440, and transport of data between the display other elements of the device1401can be controlled via the interface1440. Methods as described herein can be implemented by way of machine (e.g., computer processor) executable code stored on an electronic storage location of the digital processing device1401, such as, for example, on the memory1410or electronic storage unit1415. The machine executable or machine-readable code can be provided in the form of a software application or software module. During use, the code can be executed by the processor1405. In some cases, the code can be retrieved from the storage unit1415and stored on the memory1410for ready access by the processor1405. In some situations, the electronic storage unit1415can be precluded, and machine-executable instructions are stored on memory1410. In some embodiments, a remote device1402is configured to communicate with the digital processing device1401, and may comprise any mobile computing device, non-limiting examples of which include a tablet computer, laptop computer, smartphone, or smartwatch. For example, in some embodiments, the remote device1402is a smartphone of the user that is configured to receive information from the digital processing device1401of the device or system described herein in which the information can include a summary, sensor data, or other data. In some embodiments, the remote device1402is a server on the network configured to send and/or receive data from the device or system described herein. Definitions Unless defined otherwise, all terms of art, notations and other technical and scientific terms or terminology used herein are intended to have the same meaning as is commonly understood by one of ordinary skill in the art to which the claimed subject matter pertains. In some cases, terms with commonly understood meanings are defined herein for clarity and/or for ready reference, and the inclusion of such definitions herein should not necessarily be construed to represent a substantial difference over what is generally understood in the art. In the present description, any percentage range, ratio range, or integer range is to be understood to include the value of any integer within the recited range and, when appropriate, fractions thereof (such as one tenth and one hundredth of an integer), unless otherwise indicated. Throughout this application, various embodiments may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the disclosure. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range. As used in the specification and claims, the singular forms “a”, “an” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “a sample” includes a plurality of samples, including mixtures thereof. The use of the alternative (e.g., “or”) should be understood to mean either one, both, or any combination thereof of the alternatives. As used herein, the terms “include” and “comprise” are used synonymously. The term “about” or “approximately” can mean within an acceptable error range for the particular value as determined by one of ordinary skill in the art, which will depend in part on how the value is measured or determined, e.g., the limitations of the measurement system. For example, “about” can mean plus or minus 10%, per the practice in the art. Alternatively, “about” can mean a range of plus or minus 20%, plus or minus 10%, plus or minus 5%, or plus or minus 1% of a given value. Where particular values are described in the application and claims, unless otherwise stated, the term “about” means within an acceptable error range for the particular value that should be assumed. Also, where ranges and/or subranges of values are provided, the ranges and/or subranges can include the endpoints of the ranges and/or subranges. The terms “determining”, “measuring”, “evaluating”, “assessing,” and “analyzing” are often used interchangeably herein to refer to forms of measurement and include determining if an element is present or not (for example, detection). These terms can include quantitative, qualitative or quantitative and qualitative determinations. Assessing is alternatively relative or absolute. The terms “subject,” “individual,” or “patient” are often used interchangeably herein. A “subject” can be an animal. The subject can be a mammal. The mammal can be a human. The subject may have a disease or a condition that can be treated by a surgical procedure. In some cases, the subject is not necessarily diagnosed or suspected of being at high risk for the disease or a condition but undergoes a surgical procedure. The term “in vivo” is used to describe an event that takes place in a subject's body. The term “ex vivo” is used to describe an event that takes place outside of a subject's body. An “ex vivo” assay is not performed on a subject. Rather, it is performed upon a sample separate from a subject. An example of an “ex vivo” assay performed on a sample is an “in vitro” assay. The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described. Examples The following examples are included for illustrative purposes only and are not intended to limit the scope of the invention. Example 1: Tracking and Registering Using Markers Provided herein is an exemplary embodiment of workflow for tracking and registering a knee joint using markers that are drilled into the in tibia and femur of the knee joint in the patient and protrude out from their placement site. The placement of the marker in order to track and register the bones of the knee joint is an invasive procedure that damages the tissue at and around the knee joint. The marker is used in marker-based tracking to track and register the knee joint and in robot-assisted surgical systems. Such invasive fixation of markers to bones may lead to complications, infections, nerve injury, and bone fracture. The marker fixation may reduce the flexibility during the procedure as the protruding markers may get in the way during the procedure. The surgical procedure may take longer to fix the marker into place than a markerless approach. Example 2: Markerless Tracking and Registering Provided herein is an exemplary embodiment of a method for markerless tracking and registering an object of interest. A light beam was projected onto a contour of an object of interest. Then, an image of the light beam projected onto the contour of the object was obtained using an imaging module. The obtained image was input into a software module for a processor. The image was segmented by applying convolution filters into segmented images. The segmented images were quantized, and 3D profiles were reconstructed from the quantized images. The reconstructed 3D profiles were converted to 2D profiles by transformation to a local coordinate system. Then, a feature vector was formed from the 2D profiles by concatenation and normalization. The object poses were predicted by applying machine learning to the feature vector. The methods and systems described herein requires shorter surgical time as the additional time to invasively place the large markers is not needed. The shorter surgical procedure time can result in better surgical outcomes, less tissue damage, and less complications for the patient. While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.

11857272

DETAILED DESCRIPTION FIGS.1-3show an implanted article physical referencing apparatus100configured in accordance with an embodiment of the present invention. The implanted article physical referencing apparatus100is an example of a variable implant article placement guide assembly configured in accordance with one or more embodiments of the present invention. The implanted article physical referencing apparatus100provide utility in surgical procedures in a manner that overcomes drawbacks that limit utility and beneficial attributes of prior art variable implant article placement guides. More specifically, the implanted article physical referencing apparatus100enables its use in minimally-invasive procedures, enables a single guide to be useful even where expected differences in patient anatomy exist (e.g., depth of surgical site associated with body fat and/or body volume) and limits the potential for human error in achieving accuracy of an intended dimensional distance between placed implant articles. The implanted article physical referencing apparatus100includes a guide body105, a first guide shaft110, a second guide shaft115and a guide body lock120. As discussed below in greater detail, the first guide shaft110and the second guide shaft115are attached to the guide body105in a spaced apart manner. In preferred embodiments, the first guide shaft110is movable between a plurality of spaced apart positions on the guide body105for enabling distance between implanted articles or locating structure for placing an implanted article (e.g., a Steinmann pin) to be selectively adjusted between a plurality of discrete guide shaft positions. The lock body120can be used to inhibit unrestricted axial movement of the first and second guide shafts110,115relative to the guide body105. In contrast to prior art devices, adjustment of the first guide shaft between a plurality of discrete location is advantageous relative to infinite adjustability over a provided range of adjustment. The first and second guide shafts110,115each have a central passage125,130that extends at least partially through the first and second guide shafts110,115along the respective longitudinal axis L1, L2thereof. In preferred embodiments, the central passages125,104of the first and second guide shafts110,115extends through an entire length thereof. When the first and second guide shafts110,115are mounted on the guide body105(e.g., when the implanted article physical referencing apparatus100is in use), the longitudinal axis L1of the first guide shaft110extends substantially parallel to the longitudinal axis L2of the second guide shaft115. As best shown inFIGS.3-5, the guide body105includes a plurality of target location guide shaft receptacles135and a reference location guide shaft receptacle140and. A longitudinal axis of all of the guide shaft receptacles extends substantially parallel to a longitudinal reference axis L1of the guide body105. Each of the target location guide shaft receptacles135is spaced-apart from each adjacent one of the target location guide shaft receptacles135. The reference location guide shaft receptacle140can be spaced away from all of the target location guide shaft receptacles135. In one or more embodiments, as shown, the longitudinal axis of each of all of the guide shaft receptacles135,140lie on a transverse reference axis T1of the guide body and two or more of the target location guide shaft receptacles140(e.g., all of the target location guide shaft receptacles140) intersect each other. The first and second guide shafts110,115each have a proximate end portion110A,115A and a distal end portion110B,115B. The proximate end portion110A of the first guide shaft110and the proximate end portion115A of the second guide shaft115each include an exterior surface engaged with any selected one of the target location guide shaft receptacles140. To this end, the proximate end portion110A of the first guide shaft110is configured to constrain unrestricted relative movement between the first guide shaft and the guide body. For example, as shown inFIG.3, the first and second guide shafts110,115can each include a cylindrical sidewall142,143having a shoulder145,150extending therefrom. The target location guide shaft receptacles135and the reference location guide shaft receptacle140can be configured mating structure such as a cylindrical, stepped sidewall passages that receive the respective one of the guide shafts110,115. The cylindrical, stepped sidewall passages of each of the shaft receptacles135,140can include a shoulder155,160that is matingly engaged by the shoulder145,150for limiting unrestricted axial displacement of the guide shafts110,115relative to the guide body105. In one or more embodiments, as best shown inFIGS.4and5, the guide shafts110,115each have a cylindrical side wall and the shaft receptacles135,140each have a mating cylindrical side wall. It is desirable to secure the first and second guide members110,115in their seated positions relative to the guide body105to provide fixed position relative to each other and relative to the guide body105. In one or more embodiments, the guide shaft lock120, guide body105and guide shafts110,115can be jointly configured for securing the first and second guide members110,115in their seated positions relative to the guide body105. In one of more other embodiments, the guide body105and guide shafts110,115can be jointly configured with mating structures (e.g., interlocking protrusions and/or groves, interference fit, snap fit, or the like) for securing the first and second guide members110,115in their seated positions relative to the guide body105without the use of the guide shaft lock120. In a preferred embodiment, as shown inFIGS.3and6-7, the guide shaft lock120has a guide body engaging portion165, a first guide shaft engaging portion170and a second guide shaft engaging portion175. The guide body engaging portion165engages a mating portion of the guide body105to constrain relative movement between the guide shaft lock and120the guide body105(e.g., in a direction along the longitudinal reference axis L1of the guide body105). In one or more embodiments, as shown, the guide body engaging portion165includes an elongated protrusion180that engages a mating groove182of the guide body105. As best shown inFIGS.3,4,7and8, the guide body engaging portion165can include one or more retention members (e.g., one or more projection184) that engage a mating structure of the guide body (e.g., one or more recesses186) for inhibiting limiting unrestricted movement guide body lock120relative to the guide body105. In one embodiment, as best shown inFIGS.6and7, the first guide shaft engaging portion170includes an elongated aperture188with an intersecting shoulder passage190and the second guide shaft engaging portion175includes an open-ended aperture192. Though engagement of the guide body engaging portion165with the mating portion of the guide body105, the guide lock120can be moved (e.g., slid) along a length of the guide body105between a guide shaft insertion position P2(FIG.2) and a lock position P1(FIG.1). In the guide shaft insertion position P2(FIG.2), the shoulder passage190is aligned with a selected one of the target location guide shaft receptacles135for allowing the first guide shaft110to be seated in the selected on of the target location guide shaft receptacles135and (to the extent necessary) for allowing the second guide shaft115to be seated in the reference location guide shaft receptacle140. When seated in the reference location guide shaft receptacle140, a longitudinal axis of the second guide shaft115extends substantially colinear with the longitudinal reference axis L1of the guide body105. Moving the guide body lock to the lock position P1(FIG.1) causes the shoulders145,150to become trapped under a respective overlying portion of the first and second guide shaft engaging portions170,175, thereby constraining relative movement between the guide body105and the first and second guide shafts110,115in a direction along the longitudinal reference axis L1of the guide body105to prevent the first and second guide shafts110,115from becoming unseated from within the respective guide shaft receptacle135,140. In use, the guide body lock120is engaged with the guide body105such that the intersecting shoulder passage190is aligned with a selected one of the target location guide shaft receptacles135of the guide body105. The first guide shaft110can then be inserted into the selected on of the target location guide shaft receptacles135and the second guide shaft115can be inserted into the reference location guide shaft receptacle140. The guide shafts110,115are each inserted to a seated position at which the shoulder145,150thereof engages the shoulder155,160of the respective shaft receptacle135,140, as shown inFIG.2. In the seated position, the guide shafts110,115are in a fixed position relative to the guide body105. The guide body lock is then moved to the lock position P2, as shown inFIG.1. Advantageously, embodiments of the present invention can permit the guide shafts110,115to be selected from a respective set of guide shafts having different configuration (e.g., length, exterior diameter, etc.). The selected guide shafts be inserted in the respective guide shaft receptacle135,140(before and/or during a surgical procedure) for use with the guide body105and secured in place using the guide body lock (or other retention means). Alternatively, in one or more embodiments, the first guide shaft110and/or the second guide shaft115can be double ended with respect to the respective shoulder145,150such that insertion from a first end provides a first effective guide shaft length and insertion from a second end provides a second effective guide shaft length. Components of implanted article physical referencing apparatuses configured in accordance with embodiments of the present invention (e.g., guide body, guide hafts, guide body lock) can be made from any suitable material using any suitable fabrication process. Examples of suitable materials include, but are not limited to, polymeric materials and metallic materials. Examples of suitable fabrication processes include, but are not limited to, molding, machining, 3-D printing, extrusion, casting and the like. Although the invention has been described with reference to several exemplary embodiments, it is understood that the words that have been used are words of description and illustration, rather than words of limitation. Changes may be made within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the invention in all its aspects. Although the invention has been described with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed; rather, the invention extends to all functionally equivalent technologies, structures, methods and uses such as are within the scope of the appended claims.

11857273

DETAILED DESCRIPTION It is to be understood that the present disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the description herein or illustrated in the drawings. The teachings of the present disclosure may be used and practiced in other embodiments and practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. The following discussion is presented to enable a person skilled in the art to make and use embodiments of the present disclosure. Various modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the principles herein can be applied to other embodiments and applications without departing from embodiments of the present disclosure. Thus, the embodiments are not intended to be limited to embodiments shown, but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the embodiments. Skilled artisans will recognize the examples provided herein have many useful alternatives and fall within the scope of the embodiments. Turning now to the drawing,FIGS.1and2illustrate a surgical robot system100in accordance with an example embodiment. Surgical robot system100may include, for example, a surgical robot102, one or more robot arms104, a base106, a display110, an end-effector112, for example, including a guide tube114, and one or more tracking markers118. The surgical robot system100may include a patient tracking device116also including one or more tracking markers118, which is adapted to be secured directly to the patient210(e.g., to the bone of the patient210). The surgical robot system100may also utilize a camera200, for example, positioned on a camera stand202. The camera stand202can have any suitable configuration to move, orient, and support the camera200in a desired position. The camera200may include any suitable camera or cameras, such as one or more infrared cameras (e.g., bifocal or stereophotogrammetric cameras), able to identify, for example, active and passive tracking markers118in a given measurement volume viewable from the perspective of the camera200. The camera200may scan the given measurement volume and detect the light that comes from the markers118in order to identify and determine the position of the markers118in three-dimensions. For example, active markers118may include infrared-emitting markers that are activated by an electrical signal (e.g., infrared light emitting diodes (LEDs)), and passive markers118may include retro-reflective markers that reflect infrared light (e.g., they reflect incoming IR radiation into the direction of the incoming light), for example, emitted by illuminators on the camera200or other suitable device. FIGS.1and2illustrate a potential configuration for the placement of the surgical robot system100in an operating room environment. For example, the robot102may be positioned near or next to patient210. Although depicted near the head of the patient210, it will be appreciated that the robot102can be positioned at any suitable location near the patient210depending on the area of the patient210undergoing the operation. The camera200may be separated from the robot system100and positioned at the foot of patient210. This location allows the camera200to have a direct visual line of sight to the surgical field208. Again, it is contemplated that the camera200may be located at any suitable position having line of sight to the surgical field208. In the configuration shown, the surgeon120may be positioned across from the robot102, but is still able to manipulate the end-effector112and the display110. A surgical assistant126may be positioned across from the surgeon120again with access to both the end-effector112and the display110. If desired, the locations of the surgeon120and the assistant126may be reversed. The traditional areas for the anesthesiologist122and the nurse or scrub tech124remain unimpeded by the locations of the robot102and camera200. With respect to the other components of the robot102, the display110can be attached to the surgical robot102and in other example embodiments, display110can be detached from surgical robot102, either within a surgical room with the surgical robot102, or in a remote location. End-effector112may be coupled to the robot arm104and controlled by at least one motor. In example embodiments, end-effector112can comprise a guide tube114, which is able to receive and orient a surgical instrument608(described further herein) used to perform surgery on the patient210. As used herein, the term “end-effector” is used interchangeably with the terms “end-effectuator” and “effectuator element.” The term “instrument” is used in a non-limiting manner and can be used interchangeably with “tool” to generally refer to any type of device that can be used during a surgical procedure in accordance with embodiments disclosed herein. Example instruments include, without limitation, drills, screwdriver s, saws, dilators, retractors, implant inserters, and implants such as a screws, spacers, interbody fusion devices, plates, rods, etc. Although generally shown with a guide tube114, it will be appreciated that the end-effector112may be replaced with any suitable instrumentation suitable for use in surgery. In some embodiments, end-effector112can comprise any known structure for effecting the movement of the surgical instrument608in a desired manner. The surgical robot102is able to control the translation and orientation of the end-effector112. The robot102is able to move end-effector112along x-, y-, and z-axes, for example. The end-effector112can be configured for selective rotation about one or more of the x-, y-, and z-axis, and a Z Frame axis (such that one or more of the Euler Angles (e.g., roll, pitch, and/or yaw) associated with end-effector112can be selectively controlled). In some example embodiments, selective control of the translation and orientation of end-effector112can permit performance of medical procedures with significantly improved accuracy compared to conventional robots that utilize, for example, a six degree of freedom robot arm comprising only rotational axes. For example, the surgical robot system100may be used to operate on patient210, and robot arm104can be positioned above the body of patient210, with end-effector112selectively angled relative to the z-axis toward the body of patient210. In some example embodiments, the pose of the surgical instrument608can be dynamically updated so that surgical robot102can be aware of the pose of the surgical instrument608at all times during the procedure. Consequently, in some example embodiments, surgical robot102can move the surgical instrument608to the desired pose quickly without any further assistance from a physician (unless the physician so desires). As used herein, the term “pose” refers to the position and/or the rotational angle of one object (e.g., dynamic reference array, end-effector, surgical instrument, anatomical structure, etc.) relative to another object and/or to a defined coordinate system. A pose may therefore be defined based on only the multidimensional position of one object relative to another object and/or relative to a defined coordinate system, based on only the multidimensional rotational angles of the object relative to another object and/or to a defined coordinate system, or based on a combination of the multidimensional position and the multidimensional rotational angles. The term “pose” therefore is used to refer to position, rotational angle, or combination thereof. In some further embodiments, surgical robot102can be configured to correct the path of the surgical instrument608if the surgical instrument608strays from the selected, preplanned trajectory. In some example embodiments, surgical robot102can be configured to permit stoppage, modification, and/or manual control of the movement of end-effector112and/or the surgical instrument608. Thus, in use, in example embodiments, a physician or other user can operate the system100, and has the option to stop, modify, or manually control the autonomous movement of end-effector112and/or the surgical instrument608. Further details of surgical robot system100including the control and movement of a surgical instrument608by surgical robot102can be found in U.S. patent application Ser. No. 13/924,505, which is incorporated herein by reference in its entirety. The robotic surgical system100can comprise one or more tracking markers118configured to track the movement of robot arm104, end-effector112, patient210, and/or the surgical instrument608in three dimensions. In example embodiments, a plurality of tracking markers118can be mounted (or otherwise secured) thereon to an outer surface of the robot102, such as, for example and without limitation, on base106of robot102, on robot arm104, or on the end-effector112. In example embodiments, at least one tracking marker118of the plurality of tracking markers118can be mounted or otherwise secured to the end-effector112. One or more tracking markers118can further be mounted (or otherwise secured) to the patient210. In example embodiments, the plurality of tracking markers118can be positioned on the patient210spaced apart from the surgical field208to reduce the likelihood of being obscured by the surgeon, surgical instruments, or other parts of the robot102. Further, one or more tracking markers118can be further mounted (or otherwise secured) to the surgical instruments608(e.g., a screwdriver, dilator, implant inserter, or the like). Thus, the tracking markers118enable each of the marked objects (e.g., the end-effector112, the patient210, and the surgical instruments608) to be tracked by the robot102via the camera200. In example embodiments, system100can use tracking information collected from each of the marked objects to calculate the pose (e.g., orientation and location), for example, of the end-effector112, the surgical instrument608(e.g., positioned in the tube114of the end-effector112), and the relative position of the patient210. The markers118may include radiopaque or optical markers. The markers118may be suitably shaped include spherical, spheroid, cylindrical, cube, cuboid, or the like. In example embodiments, one or more of markers118may be optical markers. In some embodiments, the positioning of one or more tracking markers118on end-effector112can maximize the accuracy of the positional measurements by serving to check or verify the position of end-effector112. Further details of surgical robot system100including the control, movement and tracking of surgical robot102and of a surgical instrument608can be found in U.S. patent application Ser. No. 13/924,505, which is incorporated herein by reference in its entirety. Example embodiments include one or more markers118coupled to the surgical instrument608. In example embodiments, these markers118, for example, coupled to the patient210and surgical instruments608, as well as markers118coupled to the end-effector112of the robot102can comprise conventional infrared light-emitting diodes (LEDs) or an Optotrak® diode capable of being tracked using a commercially available infrared optical tracking system such as Optotrak®. Optotrak® is a registered trademark of Northern Digital Inc., Waterloo, Ontario, Canada. In other embodiments, markers118can comprise conventional reflective spheres capable of being tracked using a commercially available optical tracking system such as Polaris Spectra. Polaris Spectra is also a registered trademark of Northern Digital, Inc. In an example embodiment, the markers118coupled to the end-effector112are active markers which comprise infrared light-emitting diodes which may be turned on and off, and the markers118coupled to the patient210and the surgical instruments608comprise passive reflective spheres. In example embodiments, light emitted from and/or reflected by markers118can be detected by camera200and can be used to monitor the pose and movement of the marked objects. In alternative embodiments, markers118can comprise a radio-frequency and/or electromagnetic reflector or transceiver and the camera200can include or be replaced by a radio-frequency and/or electromagnetic transceiver. Similar to surgical robot system100,FIG.3illustrates a surgical robot system300and camera stand302, in a docked configuration, consistent with an example embodiment of the present disclosure. Surgical robot system300may comprise a robot301including a display304, upper arm306, lower arm308, end-effector310, vertical column312, casters314, cabinet316, tablet drawer318, and ring324of information. Camera stand302may comprise camera326. These components are described in greater with respect toFIG.5.FIG.3illustrates the surgical robot system300in a docked configuration where the camera stand302is nested with the robot301, for example, when not in use. It will be appreciated by those skilled in the art that the camera326and robot301may be separated from one another and positioned at any appropriate pose during the surgical procedure, for example, as shown inFIGS.1and2. FIG.4illustrates a base400consistent with an example embodiment of the present disclosure. Base400may be a portion of surgical robot system300and comprise cabinet316. Cabinet316may house certain components of surgical robot system300including but not limited to a battery402, a power distribution module404, a platform interface board module406, a computer408, a handle412, and a tablet drawer414. The connections and relationship between these components is described in greater detail with respect toFIG.5. FIG.5illustrates a block diagram of certain components of an example embodiment of surgical robot system300. Surgical robot system300may comprise platform subsystem502, computer subsystem504, motion control subsystem506, and tracking subsystem532. Platform subsystem502may further comprise battery402, power distribution module404, platform interface board module406, and tablet charging station534. Computer subsystem504may further comprise computer408, display304, and speaker536. Motion control subsystem506may further comprise driver circuit508, motors510,512,514,516,518, stabilizers520,522,524,526, end-effector310, and controller538. Tracking subsystem532may further comprise position sensor540and camera converter542. System300may also comprise a foot pedal544and tablet546. Input power is supplied to system300via a power supply548which may be provided to power distribution module404. Power distribution module404receives input power and is configured to generate different power supply voltages that are provided to other modules, components, and subsystems of system300. Power distribution module404may be configured to provide different voltage supplies to platform interface board module406, which may be provided to other components such as computer408, display304, speaker536, driver circuit508to, for example, power motors512,514,516,518and end-effector310, motor510, ring324, camera converter542, and other components for system300for example, fans for cooling the electrical components within cabinet316. Power distribution module404may also provide power to other components such as tablet charging station534that may be located within tablet drawer318. Tablet charging station534may be in wireless or wired communication with tablet546for charging tablet546. Tablet546may be used by a surgeon consistent with the present disclosure and described herein. Power distribution module404may also be connected to battery402, which serves as temporary power source in the event that power distribution module404does not receive power from power supply548. At other times, power distribution module404may serve to charge battery402if necessary. Other components of platform subsystem502may also include connector panel320, control panel322, and ring324. Connector panel320may serve to connect different devices and components to system300and/or associated components and modules. Connector panel320may contain one or more ports that receive lines or connections from different components. For example, connector panel320may have a ground terminal port that may ground system300to other equipment, a port to connect foot pedal544to system300, a port to connect to tracking subsystem532, which may comprise position sensor540, camera converter542, and cameras326associated with camera stand302. Connector panel320may also include other ports to allow USB, Ethernet, HDMI communications to other components, such as computer408. Control panel322may provide various buttons or indicators that control operation of system300and/or provide information regarding system300. For example, control panel322may include buttons to power on or off system300, lift or lower vertical column312, and lift or lower stabilizers520-526that may be designed to engage casters314to lock system300from physically moving. Other buttons may stop system300in the event of an emergency, which may remove all motor power and apply mechanical brakes to stop all motion from occurring. Control panel322may also have indicators notifying the user of certain system conditions such as a line power indicator or status of charge for battery402. Ring324may be a visual indicator to notify the user of system300of different modes that system300is operating under and certain warnings to the user. Computer subsystem504includes computer408, display304, and speaker536. Computer504includes an operating system and software to operate system300. Computer504may receive and process information from other components (for example, tracking subsystem532, platform subsystem502, and/or motion control subsystem506) in order to display information to the user. Further, computer subsystem504may also include speaker536to provide audio to the user. Tracking subsystem532may include position sensor540and camera converter542. Tracking subsystem532may correspond to camera stand302including camera326as described with respect toFIG.3. Position sensor540may be camera326. Tracking subsystem may track the pose of certain markers that are located on the different components of system300and/or instruments used by a user during a surgical procedure. This tracking may be conducted in a manner consistent with the present disclosure including the use of infrared technology that tracks the pose of active or passive elements, such as LEDs or reflective markers, respectively. The pose of structures having these types of markers may be provided to computer408which may be shown to a user on display304. For example, a surgical instrument608having these types of markers and tracked in this manner (which may be referred to as a navigational space) may be shown to a user in relation to a three dimensional image of a patient's anatomical structure. Motion control subsystem506may be configured to physically move vertical column312, upper arm306, lower arm308, or rotate end-effector310. The physical movement may be conducted through the use of one or more motors510-518. For example, motor510may be configured to vertically lift or lower vertical column312. Motor512may be configured to laterally move upper arm308around a point of engagement with vertical column312as shown inFIG.3. Motor514may be configured to laterally move lower arm308around a point of engagement with upper arm308as shown inFIG.3. Motors516and518may be configured to move end-effector310in a manner such that one may control the roll and one may control the tilt, thereby providing multiple angles that end-effector310may be moved. These movements may be achieved by controller538which may control these movements through load cells disposed on end-effector310and activated by a user engaging these load cells to move system300in a desired manner. Moreover, system300may provide for automatic movement of vertical column312, upper arm306, and lower arm308through a user indicating on display304(which may be a touchscreen input device) the pose of a surgical instrument or component on three dimensional image of the patient's anatomy on display304. The user may initiate this automatic movement by stepping on foot pedal544or some other input means. FIG.6illustrates a surgical robot system600consistent with an example embodiment. Surgical robot system600may comprise end-effector602, robot arm604, guide tube606, instrument608, and robot base610. Instrument instrument608may be attached to a tracking array612including one or more tracking markers (such as markers118) and have an associated trajectory614. Trajectory614may represent a path of movement that instrument608is configured to travel once it is positioned through or secured in guide tube606, for example, a path of insertion of instrument608into a patient. In an example operation, robot base610may be configured to be in electronic communication with robot arm604and end-effector602so that surgical robot system600may assist a user (for example, a surgeon) in operating on the patient210. Surgical robot system600may be consistent with previously described surgical robot system100and300. A tracking array612may be mounted on instrument608to monitor the pose (e.g., location and orientation) of instrument608. The tracking array612may be attached to an instrument608and may comprise tracking markers804. As best seen inFIG.8, tracking markers804may be, for example, light emitting diodes and/or other types of reflective markers (e.g., markers118as described elsewhere herein). The tracking devices may be one or more line of sight devices associated with the surgical robot system. As an example, the tracking devices may be one or more cameras200,326associated with the surgical robot system100,300and may also track tracking array612for a defined domain or relative orientations of the instrument608in relation to the robot arm604, the robot base610, end-effector602, and/or the patient210. The tracking devices may be consistent with those structures described in connection with camera stand302and tracking subsystem532. FIGS.7A,7B, and7Cillustrate a top view, front view, and side view, respectively, of end-effector602consistent with an example embodiment. End-effector602may comprise one or more tracking markers702. Tracking markers702may be light emitting diodes or other types of active and passive markers, such as tracking markers118that have been previously described. In an example embodiment, the tracking markers702are active infrared-emitting markers that are activated by an electrical signal (e.g., infrared light emitting diodes (LEDs)). Thus, tracking markers702may be activated such that the infrared markers702are visible to the camera200,326or may be deactivated such that the infrared markers702are not visible to the camera200,326. Thus, when the markers702are active, the end-effector602may be controlled by the system100,300,600, and when the markers702are deactivated, the end-effector602may be locked in position and unable to be moved by the system100,300,600. Markers702may be disposed on or within end-effector602in a manner such that the markers702are visible by one or more cameras200,326or other tracking devices associated with the surgical robot system100,300,600. The camera200,326or other tracking devices may track end-effector602as it moves to different positions and viewing angles by following the movement of tracking markers702. The pose of markers702and/or end-effector602may be shown on a display110,304associated with the surgical robot system100,300,600, for example, display110as shown inFIG.2and/or display304shown inFIG.3. This display110,304may allow a user to ensure that end-effector602is in a desirable position in relation to robot arm604, robot base610, the patient210, and/or the user. For example, as shown inFIG.7A, markers702may be placed around the surface of end-effector602so that a tracking device placed away from the surgical field208and facing toward the robot102,301and the camera200,326is able to view at least 3 of the markers702through a range of common orientations of the end-effector602relative to the tracking system100,300,600. For example, distribution of markers702in this way allows end-effector602to be monitored by the tracking devices when end-effector602is translated and rotated in the surgical field208. In addition, in example embodiments, end-effector602may be equipped with infrared (IR) receivers that can detect when an external camera200,326is getting ready to read markers702. Upon this detection, end-effector602may then illuminate markers702. The detection by the IR receivers that the external camera200,326is ready to read markers702may signal the need to synchronize a duty cycle of markers702, which may be light emitting diodes, to an external camera200,326. This may also allow for lower power consumption by the robotic system as a whole, whereby markers702would only be illuminated at the appropriate time instead of being illuminated continuously. Further, in example embodiments, markers702may be powered off to prevent interference with other navigation instruments, such as different types of surgical instruments608. FIG.8depicts one type of surgical instrument608including a tracking array612and tracking markers804. Tracking markers804may be of any type described herein including but not limited to light emitting diodes or reflective spheres. Markers804are monitored by tracking devices associated with the surgical robot system100,300,600and may be one or more of the line of sight cameras200,326. The cameras200,326may track the pose of instrument608based on the poses of tracking array612and markers804. A user, such as a surgeon120, may orient instrument608in a manner so that tracking array612and markers804are sufficiently recognized by the tracking device or camera200,326to display instrument608and markers804on, for example, display110of the example surgical robot system. The manner in which a surgeon120may place instrument608into guide tube606of the end-effector602and adjust the instrument608is evident inFIG.8. The hollow tube or guide tube114,606of the end-effector112,310,602is sized and configured to receive at least a portion of the surgical instrument608. The guide tube114,606is configured to be oriented by the robot arm104such that insertion and trajectory for the surgical instrument608is able to reach a desired anatomical target within or upon the body of the patient210. The surgical instrument608may include at least a portion of a generally cylindrical instrument. Although a screwdriver is exemplified as the surgical instrument608, it will be appreciated that any suitable surgical instrument608may be positioned by the end-effector602. Further examples of the surgical instrument608include one or more of a guide wire, cannula, a retractor, a drill, a reamer, a screwdriver, an insertion instrument, and a removal instrument. Although the guide tube114,606is generally shown as having a cylindrical configuration, the guide tube114,606may have any suitable shape, size and configuration desired to accommodate the surgical instrument608and access the surgical site. FIGS.9A-9Cillustrate end-effector602and a portion of robot arm604consistent with an example embodiment. End-effector602may further comprise body1202and clamp1204. Clamp1204may comprise handle1206, balls1208, spring1210, and lip1212. Robot arm604may further comprise depressions1214, mounting plate1216, lip1218, and magnets1220. End-effector602may mechanically interface and/or engage with the surgical robot system and robot arm604through one or more couplings. For example, end-effector602may engage with robot arm604through a locating coupling and/or a reinforcing coupling. Through these couplings, end-effector602may fasten with robot arm604outside a flexible and sterile barrier. In an example embodiment, the locating coupling may be a magnetically kinematic mount and the reinforcing coupling may be a five bar over center clamping linkage. With respect to the locating coupling, robot arm604may comprise mounting plate1216, which may be non-magnetic material, one or more depressions1214, lip1218, and magnets1220. Magnet1220is mounted below each of depressions1214. Portions of clamp1204may comprise magnetic material and be attracted by one or more magnets1220. Through the magnetic attraction of clamp1204and robot arm604, balls1208become seated into respective depressions1214. For example, balls1208as shown inFIG.9Bwould be seated in depressions1214as shown inFIG.9A. This seating may be considered a magnetically-assisted kinematic coupling. Magnets1220may be configured to be strong enough to support the entire weight of end-effector602regardless of the orientation of end-effector602. The locating coupling may be any style of kinematic mount that uniquely restrains six degrees of freedom. With respect to the reinforcing coupling, portions of clamp1204may be configured to be a fixed ground link and as such clamp1204may serve as a five bar linkage. Closing clamp handle1206may fasten end-effector602to robot arm604as lip1212and lip1218engage clamp1204in a manner to secure end-effector602and robot arm604. When clamp handle1206is closed, spring1210may be stretched or stressed while clamp1204is in a locked position. The locked position may be a position that provides for linkage past center. Because of a closed position that is past center, the linkage will not open absent a force applied to clamp handle1206to release clamp1204. Thus, in a locked position end-effector602may be robustly secured to robot arm604. Spring1210may be a curved beam in tension. Spring1210may be comprised of a material that exhibits high stiffness and high yield strain such as virgin PEEK (poly-ether-ether-ketone). The linkage between end-effector602and robot arm604may provide for a sterile barrier between end-effector602and robot arm604without impeding fastening of the two couplings. The reinforcing coupling may be a linkage with multiple spring members. The reinforcing coupling may latch with a cam or friction based mechanism. The reinforcing coupling may also be a sufficiently powerful electromagnet that will support fastening end-effector112to robot arm604. The reinforcing coupling may be a multi-piece collar completely separate from either end-effector602and/or robot arm604that slips over an interface between end-effector602and robot arm604and tightens with a screw mechanism, an over center linkage, or a cam mechanism. Referring toFIGS.10and11, prior to or during a surgical procedure, certain registration procedures may be conducted in order to track objects and a target anatomical structure of the patient210both in a navigation space and an image space. In order to conduct such registration, a registration system1400may be used as illustrated inFIG.10. In order to track the position of the patient210, a patient tracking device116may include a patient fixation instrument1402to be secured to a rigid anatomical structure of the patient210and a dynamic reference array1404(also referred to as dynamic reference base (DRB)) may be securely attached to the patient fixation instrument1402. For example, patient fixation instrument1402may be inserted into opening1406of dynamic reference array1404. Dynamic reference array1404, also referred to as a dynamic reference base, may contain markers1408that are visible to tracking devices, such as tracking subsystem532. These markers1408may be optical markers or reflective spheres, such as tracking markers118, as previously discussed herein. Patient fixation instrument1402is attached to a rigid anatomy of the patient210and may remain attached throughout the surgical procedure. In an example embodiment, patient fixation instrument1402is attached to a rigid area of the patient210, for example, a bone that is located away from the targeted anatomical structure subject to the surgical procedure. In order to track the targeted anatomical structure, dynamic reference array1404is associated with the targeted anatomical structure through the use of a registration fixture that is temporarily placed on or near the targeted anatomical structure in order to register the dynamic reference array1404with the pose of the targeted anatomical structure. A registration fixture1410is attached to patient fixation instrument1402through the use of a pivot arm1412. Pivot arm1412is attached to patient fixation instrument1402by inserting patient fixation instrument1402through an opening1414of registration fixture1410. Pivot arm1412is attached to registration fixture1410by, for example, inserting a knob1416through an opening1418of pivot arm1412. Using pivot arm1412, registration fixture1410may be placed over the targeted anatomical structure and its pose may be determined in an image space and navigation space using tracking markers1420and/or fiducials1422on registration fixture1410. Registration fixture1410may contain a collection of markers1420that are visible in a navigational space (for example, markers1420may be detectable by tracking subsystem532). Tracking markers1420may be optical markers visible in infrared light as previously described herein. Registration fixture1410may also contain a collection of fiducials1422, for example, such as bearing balls, that are visible in an imaging space (for example, a three dimension CT image). As described in greater detail with respect toFIG.11, using registration fixture1410, the targeted anatomical structure may be associated with dynamic reference array1404thereby allowing depictions of objects in the navigational space to be overlaid on images of the anatomical structure. Dynamic reference array1404, located at a position away from the targeted anatomical structure, may become a reference point thereby allowing removal of registration fixture1410and/or pivot arm1412from the surgical area. FIG.11provides example operations1500for registration consistent with the present disclosure. The illustrated operations1500begins at step1502wherein an image volume containing a graphical representation (or image(s)) of the targeted anatomical structure may be imported into system100,300600, for example computer408. The image volume may be three dimensional CT or a fluoroscope scan of the targeted anatomical structure of the patient210which includes registration fixture1410and a detectable imaging pattern of markers1420, e.g., fiducials. At step1504, an imaging pattern of markers1420(e.g., fiducials) is detected and registered in the imaging space and stored in computer408. Optionally, at this time at step1506, a graphical representation of the registration fixture1410may be overlaid on the images of the targeted anatomical structure. At step1508, a navigational pattern of registration fixture1410is detected and registered by recognizing markers1420. Markers1420may be optical markers that are recognized in the navigation space through infrared light by tracking subsystem532via position sensor540. Thus, the pose and other information of the targeted anatomical structure is registered in the navigation space. Therefore, registration fixture1410may be recognized in both the image space through the use of fiducials1422and the navigation space through the use of markers1420. At step1510, the registration of registration fixture1410in the image space is transferred to the navigation space. This transferal is done, for example, by using the relative position of the imaging pattern of fiducials1422compared to the position of the navigation pattern of markers1420. At step1512, registration of the navigation space of registration fixture1410(having been registered with the image space) is further transferred to the navigation space of dynamic registration array1404attached to patient fixation instrument1402. Thus, registration fixture1410may be removed and dynamic reference array1404may be used to track the targeted anatomical structure in both the navigation and image space because the navigation space is associated with the image space. At steps1514and1516, the navigation space may be overlaid on the image space and objects with markers visible in the navigation space (for example, surgical instruments608with optical markers804). The objects may be tracked through graphical representations of the surgical instrument608on the images of the targeted anatomical structure. FIGS.12A-12Billustrate imaging systems1304that may be used in conjunction with robot systems100,300,600to acquire pre-operative, intra-operative, post-operative, and/or real-time image data of patient210. Any appropriate subject matter may be imaged for any appropriate procedure using the imaging system1304. The imaging system1304may be any imaging device such as imaging device1306and/or a C-arm1308device. It may be desirable to take x-rays of patient210from a number of different positions, without the need for frequent manual repositioning of patient210which may be required in an x-ray system. As illustrated inFIG.12A, the imaging system1304may be in the form of a C-arm1308that includes an elongated C-shaped member terminating in opposing distal ends1312of the “C” shape. C-shaped member1130may further comprise an x-ray source1314and an image receptor1316. The space within C-arm1308of the arm may provide room for the physician to attend to the patient substantially free of interference from x-ray support structure1318. As illustrated inFIG.12B, the imaging system may include imaging device1306having a gantry housing1324attached to a support structure imaging device support structure1328, such as a wheeled mobile cart1330with wheels1332, which may enclose an image capturing portion, not illustrated. The image capturing portion may include an x-ray source and/or emission portion and an x-ray receiving and/or image receiving portion, which may be disposed about one hundred and eighty degrees from each other and mounted on a rotor (not illustrated) relative to a track of the image capturing portion. The image capturing portion may be operable to rotate three hundred and sixty degrees during image acquisition. The image capturing portion may rotate around a central point and/or axis, allowing image data of patient210to be acquired from multiple directions or in multiple planes. Although certain imaging systems1304are exemplified herein, it will be appreciated that any suitable imaging system may be selected by one of ordinary skill in the art. Turning now toFIGS.13A-13C, the surgical robot system100,300,600relies on accurate positioning of the end-effector112,602, surgical instruments608, and/or the patient210(e.g., patient tracking device116) relative to the desired surgical area. In the embodiments shown inFIGS.13A-13C, the tracking markers118,804are rigidly attached to a portion of the instrument608and/or end-effector112. FIG.13Adepicts part of the surgical robot system100with the robot102including base106, robot arm104, and end-effector112. The other elements, not illustrated, such as the display, marker tracking cameras, etc. may also be present as described herein.FIG.13Bdepicts a close-up view of the end-effector112with guide tube114and a plurality of tracking markers118rigidly affixed to the end-effector112. In this embodiment, the plurality of tracking markers118are attached to the end-effector112configured as a guide tube.FIG.13Cdepicts an instrument608(in this case, a probe608A) with a plurality of tracking markers804rigidly affixed to the instrument608. As described elsewhere herein, the instrument608could include any suitable surgical instrument, such as, but not limited to, guide wire, cannula, a retractor, a drill, a reamer, a screwdriver, an insertion instrument, a removal instrument, or the like. When tracking an instrument608, end-effector112, or other object to be tracked in 3D, an array of tracking markers118,804may be rigidly attached to a portion of the instrument608or end-effector112. Preferably, the tracking markers118,804are attached such that the markers118,804are out of the way (e.g., not impeding the surgical operation, visibility, etc.). The markers118,804may be affixed to the instrument608, end-effector112, or another object to be tracked, for example, with an array612. Usually three or four markers118,804are used with an array612. The array612may include a linear section, a cross piece, and may be asymmetric such that the markers118,804are at different relative poses with respect to one another. For example, as shown inFIG.13C, a probe608A with a 4-marker tracking array612is shown, andFIG.13Bdepicts the end-effector112with a different 4-marker tracking array612. InFIG.13C, the tracking array612functions as the handle620of the probe608A. Thus, the four markers804are attached to the handle620of the probe608A, which is out of the way of the shaft622and tip624. Stereophotogrammetric tracking of these four markers804allows the instrument608to be tracked as a rigid body and for the tracking system100,300,600to precisely determine the location of the tip624and the orientation of the shaft622while the probe608A is moved around within view of tracking cameras200,326. To enable automatic tracking of one or more instruments608, end-effector112, or other object to be tracked in 3D (e.g., multiple rigid bodies), the markers118,804on each instrument608, end-effector112, or the like, are arranged asymmetrically with a known inter-marker spacing. The reason for asymmetric alignment is so that it is unambiguous which marker118,804corresponds to a particular pose on the rigid body and whether markers118,804are being viewed from the front or back, i.e., mirrored. For example, if the markers118,804were arranged in a square on the instrument608or end-effector112, it would be unclear to the system100,300,600which marker118,804corresponded to which corner of the square. For example, for the probe608A, it would be unclear which marker804was closest to the shaft622. Thus, it would be unknown which way the shaft622was extending from the array612. Accordingly, each array612and thus each instrument608, end-effector112, or other object to be tracked should have a unique marker pattern to allow it to be distinguished from other instruments608or other objects being tracked. Asymmetry and unique marker patterns allow the system100,300,600to detect individual markers118,804then to check the marker spacing against a stored template to determine which instrument608, end-effector112, or another object they represent. Detected markers118,804can then be sorted automatically and assigned to each tracked object in the correct order. Without this information, rigid body calculations could not then be performed to extract key geometric information, for example, such as instrument tip624and alignment of the shaft622, unless the user manually specified which detected marker118,804corresponded to which position on each rigid body. These concepts are commonly known to those skilled in the operations of 3D optical tracking. Turning now toFIGS.14A-14D, an alternative version of an end-effector912with moveable tracking markers918A-918D is shown. InFIG.14A, an array with moveable tracking markers918A-918D are shown in a first configuration, and inFIG.14Bthe moveable tracking markers918A-918D are shown in a second configuration, which is angled relative to the first configuration.FIG.14Cshows the template of the tracking markers918A-918D, for example, as seen by the cameras200,326in the first configuration ofFIG.14A; andFIG.14Dshows the template of tracking markers918A-918D, for example, as seen by the cameras200,326in the second configuration ofFIG.14B. In this embodiment, 4-marker array tracking is contemplated wherein the markers918A-918D are not all in fixed position relative to the rigid body and instead, one or more of the array markers918A-918D can be adjusted, for example, during testing, to give updated information about the rigid body that is being tracked without disrupting the process for automatic detection and sorting of the tracked markers918A-918D. When tracking any instrument, such as a guide tube914connected to the end-effector912of a robot system100,300,600, the tracking array's primary purpose is to update the pose of the end-effector912in the camera coordinate system. When using the rigid system, for example, as shown inFIG.13B, the array612of reflective markers118rigidly extend from the guide tube114. Because the tracking markers118are rigidly connected, knowledge of the marker poses in the camera coordinate system also provides exact pose of the centerline, tip, and tail of the guide tube114in the camera coordinate system. Typically, information about the pose of the end-effector112from such an array612and information about the pose of a target trajectory from another tracked source are used to calculate the required moves that must be input for each axis of the robot102that will move the guide tube114into alignment with the trajectory and move the tip to a particular pose along the trajectory vector. Navigation information can be generated based on the calculated moves, which can be displayed for guiding an operator's movement of the end-effector112and/or instrument, and/or can be provided to one or more motors that can automatically or semi-automatically cause movement of the end-effector112. Sometimes, the desired trajectory is in an awkward or unreachable pose, but if the guide tube114could be swiveled, it could be reached. For example, a very steep trajectory pointing away from the base106of the robot102might be reachable if the guide tube114could be swiveled upward beyond the limit of the pitch (wrist up-down angle) axis, but might not be reachable if the guide tube114is attached parallel to the plate connecting it to the end of the wrist. To reach such a trajectory, the base106of the robot102might be moved or a different end-effector112with a different guide tube attachment might be exchanged with the working end-effector. Both of these solutions may be time consuming and cumbersome. As best seen inFIGS.14A and14B, if the array908is configured such that one or more of the markers918A-918D are not in a fixed position and instead, one or more of the markers918A-918D can be adjusted, swiveled, pivoted, or moved, the robot102can provide updated information about the object being tracked without disrupting the detection and tracking process. For example, one of the markers918A-918D may be fixed in position and the other markers918A-918D may be moveable; two of the markers918A-918D may be fixed in position and the other markers918A-918D may be moveable; three of the markers918A-918D may be fixed in position and the other marker918A-918D may be moveable; or all of the markers918A-918D may be moveable. In the embodiment shown inFIGS.14A and14B, markers918A,918B are rigidly connected directly to a base906of the end-effector912, and markers918C,918D are rigidly connected to the guide tube914. Similar to array612, array908may be provided to attach the markers918A-918D to the end-effector912, instrument608, or another object to be tracked. In this case, however, the array908is comprised of a plurality of separate components. For example, markers918A,918B may be connected to the base906with a first array908A, and markers918C,918D may be connected to the guide tube914with a second array908B. Marker918A may be affixed to a first end of the first array908A and marker918B may be separated a linear distance and affixed to a second end of the first array908A. While first array908is substantially linear, second array908B has a bent or V-shaped configuration, with respective root ends, connected to the guide tube914, and diverging therefrom to distal ends in a V-shape with marker918C at one distal end and marker918D at the other distal end. Although specific configurations are exemplified herein, it will be appreciated that other asymmetric designs including different numbers and types of arrays908A,908B and different arrangements, numbers, and types of markers918A-918D are contemplated. The guide tube914may be moveable, swivelable, or pivotable relative to the base906, for example, across a hinge920or another connector to the base906. Thus, markers918C,918D are moveable such that when the guide tube914pivots, swivels, or moves, markers918C,918D also pivot, swivel, or move. As best seen inFIG.14A, guide tube914has a longitudinal axis916which is aligned in a substantially normal or vertical orientation such that markers918A-918D have a first configuration. Turning now toFIG.14B, the guide tube914is pivoted, swiveled, or moved such that the longitudinal axis916is now angled relative to the vertical orientation such that markers918A-918D have a second configuration, different from the first configuration. In contrast to the embodiment described forFIGS.14A-14D, if a swivel existed between the guide tube914and the arm104(e.g., the wrist attachment) with all four markers918A-918D remaining attached rigidly to the guide tube914and this swivel was adjusted by the user, the robotic system100,300,600would not be able to automatically detect that the guide tube914orientation had changed. The robotic system100,300,600would track the positions of the marker array908and would calculate incorrect robot axis moves assuming the guide tube914was attached to the wrist (the robot arm104) in the previous orientation. By keeping one or more markers918A-918D (e.g., two markers918C,918D) rigidly on the guide tube914and one or more markers918A-918D (e.g., two markers918A,918B) across the swivel, automatic detection of the new position becomes possible and correct robot moves are calculated based on the detection of a new instrument or end-effector112,912on the end of the robot arm104. One or more of the markers918A-918D are configured to be moved, pivoted, swiveled, or the like according to any suitable means. For example, the markers918A-918D may be moved by a hinge920, such as a clamp, spring, lever, slide, toggle, or the like, or any other suitable mechanism for moving the markers918A-918D individually or in combination, moving the arrays908A,908B individually or in combination, moving any portion of the end-effector912relative to another portion, or moving any portion of the instrument608relative to another portion. As shown inFIGS.14A and14B, the array908and guide tube914may become reconfigurable by simply loosening the clamp or hinge920, moving part of the array908A,908B relative to the other part908A,908B, and retightening the hinge920such that the guide tube914is oriented in a different position. For example, two markers918C,918D may be rigidly interconnected with the guide tube914and two markers918A,918B may be rigidly interconnected across the hinge920to the base906of the end-effector912that attaches to the robot arm104. The hinge920may be in the form of a clamp, such as a wing nut or the like, which can be loosened and retightened to allow the user to quickly switch between the first configuration (FIG.14A) and the second configuration (FIG.14B). The cameras200,326detect the markers918A-918D, for example, in one of the templates identified inFIGS.14C and14D. If the array908is in the first configuration (FIG.14A) and tracking cameras200,326detect the markers918A-918D, then the tracked markers match Array Template 1 as shown inFIG.14C. If the array908is the second configuration (FIG.14B) and tracking cameras200,326detect the same markers918A-918D, then the tracked markers match Array Template 2 as shown inFIG.14D. Array Template 1 and Array Template 2 are recognized by the system100,300,600as two distinct instruments, each with its own uniquely defined spatial relationship between guide tube914, markers918A-918D, and robot attachment. The user could therefore adjust the position of the end-effector912between the first and second configurations without notifying the system100,300,600of the change and the system100,300,600would appropriately adjust the movements of the robot102to stay on trajectory. In this embodiment, there are two assembly positions in which the marker array matches unique templates that allow the system100,300,600to recognize the assembly as two different instruments or two different end-effectors. In any position of the swivel between or outside of these two positions (namely, Array Template 1 and Array Template 2 shown inFIGS.14C and14D, respectively), the markers918A-918D would not match any template and the system100,300,600would not detect any array present despite individual markers918A-918D being detected by cameras200,326, with the result being the same as if the markers918A-918D were temporarily blocked from view of the cameras200,326. It will be appreciated that other array templates may exist for other configurations, for example, identifying different instruments608or other end-effectors112,912, etc. In the embodiment described, two discrete assembly positions are shown inFIGS.14A and14B. It will be appreciated, however, that there could be multiple discrete positions on a swivel joint, linear joint, combination of swivel and linear joints, pegboard, or other assembly where unique marker templates may be created by adjusting the position of one or more markers918A-918D of the array relative to the others, with each discrete position matching a particular template and defining a unique instrument608or end-effector112,912with different known attributes. In addition, although exemplified for end-effector912, it will be appreciated that moveable and fixed markers918A-918D may be used with any suitable instrument608or other object to be tracked. When using an external 3D tracking system100,300,600to track a full rigid body array of three or more markers attached to a robot's end-effector112(for example, as depicted inFIGS.13A and13B), it is possible to directly track or to calculate the 3D pose of every section of the robot102in the coordinate system of the tracking cameras200,326. The geometric orientations of joints relative to the tracker are known by design, and the linear or angular positions of joints are known from encoders for each motor of the robot102, fully defining the 3D positions of all of the moving parts from the end-effector112to the base116. Similarly, if a tracker were mounted on the base106of the robot102(not shown), it is likewise possible to track or calculate the 3D position of every section of the robot102from base106to end-effector112based on known joint geometry and joint positions from each motor's encoder. In some situations, it may be desirable to track the poses of all segments of the robot102from fewer than three markers118rigidly attached to the end-effector112. Specifically, if an instrument608is introduced into the guide tube114, it may be desirable to track full rigid body motion of the robot902with only one additional marker118being tracked. Turning now toFIGS.15A-15E, an alternative version of an end-effector1012having only a single tracking marker1018is shown. End-effector1012may be similar to the other end-effectors described herein, and may include a guide tube1014extending along a longitudinal axis1016. A single tracking marker1018, similar to the other tracking markers described herein, may be rigidly affixed to the guide tube1014. This single marker1018can serve the purpose of adding missing degrees of freedom to allow full rigid body tracking and/or can serve the purpose of acting as a surveillance marker to ensure that assumptions about robot and camera positioning are valid. The single tracking marker1018may be attached to the end-effector1012as a rigid extension to the end-effector1012that protrudes in any convenient direction and does not obstruct the surgeon's view. The tracking marker1018may be affixed to the guide tube1014or any other suitable pose of on the end-effector1012. When affixed to the guide tube1014, the tracking marker1018may be positioned at a location between first and second ends of the guide tube1014. For example, inFIG.15A, the single tracking marker1018is shown as a reflective sphere mounted on the end of a narrow shaft1017that extends forward from the guide tube1014and is positioned longitudinally above a mid-point of the guide tube1014and below the entry of the guide tube1014. This position allows the marker1018to be generally visible by cameras200,326but also would not obstruct vision of the surgeon120or collide with other instruments or objects in the vicinity of surgery. In addition, the guide tube1014with the marker1018in this position is designed for the marker array on any instrument608introduced into the guide tube1014to be visible at the same time as the single marker1018on the guide tube1014is visible. As shown inFIG.15B, when a snugly fitting instrument608is placed within the guide tube1014, the instrument608becomes mechanically constrained in 4 of 6 degrees of freedom. That is, the instrument608cannot be rotated in any direction except about the longitudinal axis1016of the guide tube1014and the instrument608cannot be translated in any direction except along the longitudinal axis1016of the guide tube1014. In other words, the instrument608can only be translated along and rotated about the centerline of the guide tube1014. If two more parameters are known, such as (1) an angle of rotation about the longitudinal axis1016of the guide tube1014; and (2) a position along the guide tube1014, then the position of the end-effector1012in the camera coordinate system becomes fully defined. Referring now toFIG.15C, the system100,300,600should be able to know when an instrument608is actually positioned inside of the guide tube1014and is not instead outside of the guide tube1014and just somewhere in view of the tracking cameras200,326. The instrument608has a longitudinal axis or centerline616and an array612with a plurality of tracked markers804. The rigid body calculations may be used to determine where the centerline616of the instrument608is located in the camera coordinate system based on the tracked position of the array612on the instrument608. The fixed normal (perpendicular) distance DF from the single marker1018to the centerline or longitudinal axis1016of the guide tube1014is fixed and is known geometrically, and the position of the single marker1018can be tracked. Therefore, when a detected distance DD from instrument centerline616to single marker1018matches the known fixed distance DF from the guide tube axis1016(e.g., guide tube centerline) to the single marker1018, it can be determined that the instrument608is either within the guide tube1014(axis616,1016of instrument608and guide tube1014coincident) or happens to be at some point in the locus of possible positions where this distance DD matches the fixed distance DF. For example, inFIG.15C, the normal detected distance DD from instrument centerline616to the single marker1018matches the fixed distance DF from guide tube axis1016to the single marker1018in both frames of data (tracked marker coordinates) represented by the transparent instrument608in two positions, and thus, additional considerations may be needed to determine when the instrument608is located in the guide tube1014. Turning now toFIG.15D, programmed logic can be used to look for frames of tracking data in which the detected distance DD from instrument centerline616to single marker1018remains fixed at the correct length despite the instrument608moving in space by more than some minimum distance relative to the single sphere1018to satisfy the condition that the instrument608is moving within the guide tube1014. For example, a first frame F1 may be detected with the instrument608in a first position and a second frame F2 may be detected with the instrument608in a second position (namely, moved linearly with respect to the first position). The markers804on the instrument array612may move by more than a given amount (e.g., more than 5 mm total) from the first frame F1 to the second frame F2. Even with this movement, the detected distance DD from the instrument centerline vector C′ to the single marker1018is substantially identical in both the first frame F1 and the second frame F2. Logistically, the surgeon120or user could place the instrument608within the guide tube1014and slightly rotate it or slide it down into the guide tube1014and the system100,300,600would be able to detect that the instrument608is within the guide tube1014from tracking of the five markers (four markers804on instrument608plus single marker1018on guide tube1014). Knowing that the instrument608is within the guide tube1014, all 6 degrees of freedom may be calculated that define the position and orientation of the end-effector1012in space. Without the single marker1018, even if it is known with certainty that the instrument608is within the guide tube1014, it is unknown where the guide tube1014is located along the instrument's centerline vector C′ and how the guide tube1014is rotated relative to the centerline vector C′. With emphasis onFIG.15E, the presence of the single marker1018being tracked as well as the four markers804on the instrument608, it is possible to construct the centerline vector C′ of the guide tube1014and instrument608and the normal vector through the single marker1018and through the centerline vector C′. This normal vector has an orientation that is in a known orientation relative to the forearm of the robot distal to the wrist (in this example, oriented parallel to that segment) and intersects the centerline vector C′ at a specific fixed position. For convenience, three mutually orthogonal vectors k′, j′, can be constructed, as shown inFIG.15E, defining rigid body position and orientation of the guide tube1014. One of the three mutually orthogonal vectors k′ is constructed from the centerline vector C′, the second vector j is constructed from the normal vector through the single marker1018, and the third vector i′ is the vector cross product of the first and second vectors k′, j′. The robot's joint positions relative to these vectors k′, j′, i′ are known and fixed when all joints are at zero, and therefore rigid body calculations can be used to determine the pose of any section of the robot relative to these vectors k′, j′, i′ when the robot is at a home position. During robot movement, if the positions of the instrument markers804(while the instrument608is in the guide tube1014) and the position of the single marker1018are detected from the tracking system, and angles/linear positions of each joint are known from encoders, then position and orientation of any section of the robot can be determined. In some embodiments, it may be useful to fix the orientation of the instrument608relative to the guide tube1014. For example, the end-effector guide tube1014may be oriented in a particular position about its axis1016to allow machining or implant positioning. Although the orientation of anything attached to the instrument608inserted into the guide tube1014is known from the tracked markers804on the instrument608, the rotational orientation of the guide tube1014itself in the camera coordinate system is unknown without the additional tracking marker1018(or multiple tracking markers in other embodiments) on the guide tube1014. This marker1018provides essentially a “clock position” from −180° to +180° based on the orientation of the marker1018relative to the centerline vector C′. Thus, the single marker1018can provide additional degrees of freedom to allow full rigid body tracking and/or can act as a surveillance marker to ensure that assumptions about the robot and camera positioning are valid. FIG.16is a block diagram of operations1100for navigating and moving the end-effector1012(or any other end-effector described herein) of the robot102to a desired target trajectory. Another use of the single marker1018on the end-effector1012or guide tube1014is as part of the operations1100enabling the automated safe movement of the robot102without a full tracking array attached to the robot102. These operations1100function when the tracking cameras200,326do not move relative to the robot102(i.e., they are in a fixed position), the tracking system's coordinate system and robot's coordinate system are co-registered, and the robot102is calibrated such that the position and orientation of the guide tube1014can be accurately determined in the robot's Cartesian coordinate system based only on the encoded positions of each robotic axis. For these operations1100, the coordinate systems of the camera based tracker and the robot should be co-registered, meaning that the coordinate transformation from the tracking system's Cartesian coordinate system to the robot's Cartesian coordinate system is needed. For convenience, this coordinate transformation can be a 4×4 matrix of translations and rotations that is well known in the field of robotics. This transformation will be termed Tcr to refer to “transformation—camera to robot”. Once this transformation is known, any new frame of tracking data, which is received as x, y, z coordinates in vector form for each tracked marker, can be multiplied by the 4×4 matrix and the resulting x, y, z coordinates will be in the robot's coordinate system. To obtain Tcr, a full tracking array on the robot is tracked while it is rigidly attached to the robot at a pose that is known in the robot's coordinate system, then known rigid body operations are used to calculate the transformation of coordinates. It should be evident that any instrument608inserted into the guide tube1014of the robot102can provide the same rigid body information as a rigidly attached array when the additional marker1018is also read. That is, the instrument608need only be inserted to any position within the guide tube1014and at any rotation within the guide tube1014, not to a fixed position and orientation. Thus, it is possible to determine Tcr by inserting any instrument608with a tracking array612into the guide tube1014and reading the instrument's array612plus the single marker1018of the guide tube1014while at the same time determining from the encoders on each axis the current pose of the guide tube1014in the robot's coordinate system. Logic for navigating and moving the robot102to a target trajectory is provided in the operations1100ofFIG.16. Before entering the loop1102, it is assumed that the transformation Tcr was previously stored. Thus, before entering loop1102, in step1104, after the robot base106is secured, greater than or equal to one frame of tracking data of an instrument inserted in the guide tube while the robot is static is stored; and in step1106, the transformation of robot guide tube position from camera coordinates to robot coordinates Tcr is calculated from this static data and previous calibration data. Tcr should remain valid as long as the cameras200,326do not move relative to the robot102. If the cameras200,326move relative to the robot102, and Tcr needs to be re-obtained, the system100,300,600can be made to prompt the user to insert an instrument608into the guide tube1014and then automatically perform the necessary calculations. In the flowchart of operations1100, each frame of data collected includes the tracked position of the DRB1404on the patient210, the tracked position of the single marker1018on the end-effector1014, and a snapshot of the positions of each robotic axis. From the positions of the robot's axes, the pose of the single marker1018on the end-effector1012is calculated. This calculated position is compared to the actual position of the marker1018as recorded from the tracking system. If the values agree, it can be assured that the robot102is in a known pose. The transformation Tcr is applied to the tracked position of the DRB1404so that the target for the robot102can be provided in terms of the robot's coordinate system. The robot102can then be commanded to move to reach the target. After steps1104,1106, loop1102includes step1108receiving rigid body information for DRB1404from the tracking system; step1110transforming target tip and trajectory from image coordinates to tracking system coordinates; and step1112transforming target tip and trajectory from camera coordinates to robot coordinates (apply Tcr). Loop1102further includes step1114receiving a single stray marker position for robot from tracking system; and step1116transforming the single stray marker from tracking system coordinates to robot coordinates (apply stored Tcr). Loop1102also includes step1118determining current pose of the single robot marker1018in the robot coordinate system from forward kinematics. The information from steps1116and1118is used to determine step1120whether the stray marker coordinates from transformed tracked position agree with the calculated coordinates being less than a given tolerance. If yes, proceed to step1122, calculate and apply robot move to target x, y, z and trajectory. If no, proceed to step1124, halt and require full array insertion into guide tube1014before proceeding; step1126after array is inserted, recalculate Tcr; and then proceed to repeat steps1108,1114, and1118. These operations1100have advantages over operations in which the continuous monitoring of the single marker1018to verify the pose is omitted. Without the single marker1018, it would still be possible to determine the position of the end-effector1012using Tcr and to send the end-effector1012to a target pose but it would not be possible to verify that the robot102was actually in the expected pose. For example, if the cameras200,326had been bumped and Tcr was no longer valid, the robot102would move to an erroneous pose. For this reason, the single marker1018provides value with regard to safety. For a given fixed position of the robot102, it is theoretically possible to move the tracking cameras200,326to a new pose in which the single tracked marker1018remains unmoved since it is a single point, not an array. In such a case, the system100,300,600would not detect any error since there would be agreement in the calculated and tracked poses of the single marker1018. However, once the robot's axes caused the end-effector102, i.e., guide tube, to move to a new pose, the calculated and tracked poses would disagree and the safety check would be effective. The term “surveillance marker” may be used, for example, in reference to a single marker that is in a fixed pose relative to the DRB1404. In this instance, if the DRB1404is bumped or otherwise dislodged, the relative pose of the surveillance marker changes and the surgeon120can be alerted that there may be a problem with navigation. Similarly, in the embodiments described herein, with a single marker1018on the robot's guide tube1014, the system100,300,600can continuously check whether the cameras200,326have moved relative to the robot102. If registration of the tracking system's coordinate system to the robot's coordinate system is lost, such as by cameras200,326being bumped or malfunctioning or by the robot malfunctioning, the system100,300,600can alert the user and corrections can be made. Thus, this single marker1018can also be thought of as a surveillance marker for the robot102. It should be clear that with a full array permanently mounted on the robot102(e.g., the plurality of tracking markers702on end-effector602shown inFIGS.7A-7C) such functionality of a single marker1018as a robot surveillance marker is not needed because it is not required that the cameras200,326be in a fixed position relative to the robot102, and Tcr is updated at each frame based on the tracked position of the robot102. Reasons to use a single marker1018instead of a full array are that the full array is more bulky and obtrusive, thereby blocking the surgeon's view and access to the surgical field208more than a single marker1018, and line of sight to a full array is more easily blocked than line of sight to a single marker1018. Turning now toFIGS.17A-17B and18A-18B, instruments608, such as implant holders608B,608C, are depicted which include both fixed and moveable tracking markers804,806. The implant holders608B,608C may have a handle620and an outer shaft622extending from the handle620. The shaft622may be positioned substantially perpendicular to the handle620, as shown, or in any other suitable orientation. An inner shaft626may extend through the outer shaft622with a knob628at one end. Implant10,12connects to the shaft622, at the other end, at tip624of the implant holder608B,608C using typical connection mechanisms known to those of skill in the art. The knob628may be rotated, for example, to expand or articulate the implant10,12. U.S. Pat. Nos. 8,709,086 and 8,491,659, which are incorporated by reference herein, describe expandable fusion devices and operations for installation. When tracking the instrument608, such as implant holder608B,608C, the tracking array612may contain a combination of fixed markers804and one or more moveable markers806which make up the array612or is otherwise attached to the implant holder608B,608C. The navigation array612may include at least one or more (e.g., at least two) fixed position markers804, which are positioned with a known pose relative to the implant holder instrument608B,608C. These fixed markers804would not be able to move in any orientation relative to the instrument geometry and would be useful in defining where the instrument608is in space. In addition, at least one marker806is present which can be attached to the array612or the instrument itself which is capable of moving within a pre-determined boundary (e.g., sliding, rotating, etc.) relative to the fixed markers804. The system100,300,600(e.g., the software) correlates the position of the moveable marker806to a particular position, orientation, or other attribute of the implant10(such as height of an expandable interbody spacer shown inFIGS.17A-17Bor angle of an articulating interbody spacer shown inFIGS.18A-18B). Thus, the system and/or the user can determine the height or angle of the implant10,12based on the pose of the moveable marker806. In the embodiment shown inFIGS.17A-17B, four fixed markers804are used to define the implant holder608B and a fifth moveable marker806is able to slide within a pre-determined path to provide feedback on the implant height (e.g., a contracted position or an expanded position).FIG.17Ashows the implant10(e.g., expandable spacer) at its initial height, andFIG.17Bshows the implant10(e.g., expandable spacer) in the expanded state with the moveable marker806translated to a different position. In this case, the moveable marker806moves closer to the fixed markers804when the implant10is expanded, although it is contemplated that this movement may be reversed or otherwise different. The amount of linear translation of the marker806would correspond to the height of the implant10. Although only two positions are shown, it would be possible to have this as a continuous function whereby any given expansion height could be correlated to a specific position of the moveable marker806. Turning now toFIGS.18A-18B, four fixed markers804are used to define the implant holder608C and a fifth, moveable marker806is configured to slide within a pre-determined path to provide feedback on the implant articulation angle.FIG.18Ashows the articulating spacer12at its initial linear state, andFIG.18Bshows the spacer12in an articulated state at some offset angle with the moveable marker806translated to a different position. The amount of linear translation of the marker806would correspond to the articulation angle of the implant12. Although only two positions are shown, it would be possible to have this as a continuous function whereby any given articulation angle could be correlated to a specific position of the moveable marker806. In these embodiments, the moveable marker806slides continuously to provide feedback about an attribute of the implant10,12based on position. It is also contemplated that there may be discreet positions that the moveable marker806must be in which would also be able to provide further information about an implant attribute. In this case, each discreet configuration of all markers804,806correlates to a specific geometry of the implant holder608B,608C and the implant10,12in a specific orientation or at a specific height. In addition, any motion of the moveable marker806could be used for other variable attributes of any other type of navigated implant. Although depicted and described with respect to linear movement of the moveable marker806, the moveable marker806should not be limited to just sliding as there may be applications where rotation of the marker806or other movements could be useful to provide information about the implant10,12. Any relative change in position between the set of fixed markers804and the moveable marker806could be relevant information for the implant10,12or other device. In addition, although expandable and articulating implants10,12are exemplified, the instrument608could work with other medical devices and materials, such as spacers, cages, plates, fasteners, nails, screws, rods, pins, wire structures, sutures, anchor clips, staples, stents, bone grafts, biologics, cements, or the like. Turning now toFIG.19A, it is envisioned that the robot end-effector112is interchangeable with other types of end-effectors112. Moreover, it is contemplated that each end-effector112may be able to perform one or more functions based on a desired surgical procedure. For example, the end-effector112having a guide tube114may be used for guiding an instrument608as described herein. In addition, end-effector112may be replaced with a different or alternative end-effector112that controls a surgical device, instrument, or implant, for example. The alternative end-effector112may include one or more devices or instruments coupled to and controllable by the robot. By way of non-limiting example, the end-effector112, as depicted inFIG.19A, may comprise a retractor (for example, one or more retractors disclosed in U.S. Pat. Nos. 8,992,425 and 8,968,363) or one or more mechanisms for inserting or installing surgical devices such as expandable intervertebral fusion devices (such as expandable implants exemplified in U.S. Pat. Nos. 8,845,734; 9,510,954; and 9,456,903), stand-alone intervertebral fusion devices (such as implants exemplified in U.S. Pat. Nos. 9,364,343 and 9,480,579), expandable corpectomy devices (such as corpectomy implants exemplified in U.S. Pat. Nos. 9,393,128 and 9,173,747), articulating spacers (such as implants exemplified in U.S. Pat. No. 9,259,327), facet prostheses (such as devices exemplified in U.S. Pat. No. 9,539,031), laminoplasty devices (such as devices exemplified in U.S. Pat. No. 9,486,253), spinous process spacers (such as implants exemplified in U.S. Pat. No. 9,592,082), inflatables, fasteners including polyaxial screws, uniplanar screws, pedicle screws, posted screws, and the like, bone fixation plates, rod constructs and revision devices (such as devices exemplified in U.S. Pat. No. 8,882,803), artificial and natural discs, motion preserving devices and implants, spinal cord stimulators (such as devices exemplified in U.S. Pat. No. 9,440,076), and other surgical devices. The end-effector112may include one or instruments directly or indirectly coupled to the robot for providing bone cement, bone grafts, living cells, pharmaceuticals, or another deliverable to a surgical target. The end-effector112may also include one or more instruments designed for performing a discectomy, kyphoplasty, vertebrostenting, dilation, or other surgical procedure. The end-effector itself and/or the implant, device, or instrument may include one or more markers118such that the pose (e.g., location and position) of the markers118may be identified in three-dimensions. It is contemplated that the markers118may include active or passive markers118, as described herein, that may be directly or indirectly visible to the cameras200. Thus, one or more markers118located on an implant10, for example, may provide for tracking of the implant10before, during, and after implantation. As shown inFIG.19B, the end-effector112may include an instrument608or portion thereof that is coupled to the robot arm104(for example, the instrument608may be coupled to the robot arm104by the coupling mechanism shown inFIGS.9A-9C) and is controllable by the robot system100. Thus, in the embodiment shown inFIG.19B, the robot system100is able to insert implant10into a patient and expand or contract the expandable implant10. Accordingly, the robot system100may be configured to assist a surgeon or to operate partially or completely independently thereof. Thus, it is envisioned that the robot system100may be capable of controlling each alternative end-effector112for its specified function or surgical procedure. Although the robot and associated systems described herein are generally described with reference to spine applications, it is also contemplated that the robot system is configured for use in other surgical applications, including but not limited to, surgeries in trauma or other orthopedic applications (such as the placement of intramedullary nails, plates, and the like), cranial, neuro, cardiothoracic, vascular, colorectal, oncological, dental, and other surgical operations and procedures. Ultrasonic Tracking of Surgical Robot End-Effector and Surgical Instrument Relative to Patient Image Volume Numerous embodiments have been described above that utilize optical based tracking of markers. Those robotic systems utilized optical tracking registered to a medical image as feedback for positioning the robotic arm104while also displaying graphical representations of instruments and anatomical structure captured in patient image volumes to enable user visualization of instrument poses relative to the anatomical structure. Although optical-based tracking can be fast and accurate, the tracking is interrupted by blockage of line-of-sight from the markers, e.g., on patient reference array and/or the robot, to the tracking cameras200,326. Additionally, many surgical workflows with these robotic systems require x-rays or CT scans for operation and/or registration. Various embodiments of the present disclosure are directed to using a US transducer to track the pose of the surgical robot end-effector relative to patient anatomical structure captured in an image volume. A surgical robot system is provided that is positioned relative to anatomical structure by US feedback. The surgical robot system may operate without optical tracking or may be configured to operate in conjunction with optical tracking. As will be explained below, optical tracking may be used to assist in localizing anatomical structure being imaged by a US transducer and to provide operational redundancy to take over when, for example, the US transducer ceases to contact the patient and therefore no longer outputs US imaging data of the anatomical structure. In one embodiment, a surgical robot system comprises a robot, a US transducer, and at least one processor. The robot has a robot base, a robot arm coupled to the robot base, and an end-effector coupled to the robot arm, such as explained above in accordance with some embodiments. The end-effector is configured to guide movement of a surgical instrument. The US transducer is coupled to the end-effector and operative to output US imaging data of anatomical structure proximately located to the end-effector. The at least one processor is operative to obtain a 3D image volume, such as MRI or CT, for the patient and to track pose of the end-effector relative to the anatomical structure captured in the image volume based on the US imaging data. The at least one processor may include one or more data processing circuits (e.g., microprocessor and/or digital signal processor), which may be collocated or distributed across one or more data networks. The at least one processor is configured to execute program code in one or more memories to perform some or all of the operations and methods for one or more of the embodiments disclosed herein. The at least one processor may be part of the one or more the controllers disclosed herein. The end-effector can be located at the distal end of the moving arm and include a guide tube through which surgical procedures are performed. FIG.20depicts a guide tube2000configured to guide movement of a surgical instrument through the guide tube, and a US transducer unit2010formed by an array of US transducers spaced apart along a leading edge of the guide tube2000. In the example embodiment illustrated inFIG.20, the US transducers are spaced apart to form a ring-shape and are at least partially disposed within a leading edge of the guide tube2000. A ring-shaped US transducers layout may be especially operationally accurate because the ring can provide improved US visualization of anatomical structure, e.g., bone and tissues, that are distal, medial, and lateral proximately located to the guide tube2000. Other configurations of US transducers may be used with the guide tube2000. For example, a plurality of US transducers can spaced apart on the leading edge of the guide tube2000or near the leading edge of the guide tube2000, such as being mounted on a support base that is connected to the guide tube2000or another part of the end-effector. In one embodiment, the US transducer comprises a planar array of US transducers that are connected by a mounting arm to the guide tube2000or another part of the end-effector. When performing surgery, particularly cranial surgery, the inability to track the instrument (e.g., probe or tool) tip can leave the surgeon prone to coming into contact with various structures that are not the intended target, therefore risking harm to the patient. By having some trackable instrument reference able to be located on a live ultrasound, the surgeon has an understanding of the instrument tip location relative to the point of interest in the image during the procedure. In accordance with some further embodiments, the US transducer can be configured to also sense the position of a surgical instrument that is passed through the guide tube2000, such as through the ring-shaped US transducers2010. A US visible reference on a surgical instrument would limit dangers arising if the surgical instrument is not tracked, such as inaccurate instrument trajectories, instruments appearing to be bending off along trajectories, or moving the instrument too deep or shallow relative to a desired location. By utilizing live US while the tracked instrument progresses through the surgical site, the instrument's fiducials not only give information of general positioning relative to the surgical site from above, but depending on the type and number of fiducials used, more information can be given. The details of what information is identifiable in the US imaging data depends on characteristics of the fiducials formed on the tool. One type of fiducial may enable tracking of instrument depth, while a pattern of fiducials may enable tracking of instrument rotation and tracking trajectory, such as relating to skiving, bending, etc. Discrete fiducial features such as protrusions, slots, holes or indentations could be formed on the surface of the shaft of a surgical instrument, such as a screwdriver, drill, awl, tap, etc. The US transducer can be configured to output US imaging data that captures locations of the discrete features on the surgical instrument and captures anatomical structure proximately located to the guide tube2000. At least one processor (also referred to herein as “processor” below for brevity) is operative to identify in the US imaging data locations of the discrete features which are spaced apart along the surgical instrument and sensed by the US transducer, and to determine pose of the surgical instrument relative to the end-effector based on the locations of the discrete features identified in the US imaging data. In one embodiment, the processor compares a template of defined locations of the markings the instrument shaft to the locations of markings identified in the US imaging data, and can determine there from the exact longitudinal and rotational position of the surgical instrument within the guide tube2000. The processor may be configured to graphically display a representation of the surgical instrument with a determined pose overlaid on a graphical representation of anatomical structure captured in a medical image volume. This functionality can be advantageous over systems that require optical or other tracking to visualize the surgical instrument during insertion. FIGS.21A-21Cdepict differently configured surgical instruments, which have shafts configured to be tracked relative to the guide tube2000using the US transducer. FIG.21Adepicts a surgical instrument2100with patterned indentations2102at calibrated longitudinal and radial positions on the shaft. The indentations2112are configured to be detectable by the ring-shaped US transducers2010and captured in the US imaging data to enable the processor to determine the depth and rotational pose of the surgical instrument2100within the guide tube2000as the instrument shaft passes through the ring-shaped array of US transducers2010. A surgical instrument can have discrete features configured in other manners to be detectable by the US transducers2010. In some embodiments, the discrete features are configured as indentations, protrusions, slots, and/or holes spaced apart along a surface of the surgical instrument. As explained above, the US transducer can comprise an array of US transducers. To determine pose of the surgical instrument relative to the end-effector based on the locations of the discrete features identified in the US imaging data, the processor can be operative to determine depth of the surgical instrument relative to a location on the end-effector based on counting a number of the discrete features identified in the US imaging data from individual ones of the US transducers. Alternatively or additionally, when determining pose of the surgical instrument relative to the end-effector, the processor can determine rotation of the surgical instrument relative to the end-effector based on identifying rotation of the discrete features identified in the US imaging data between adjacent US transducers in the array. In a further embodiment, to determine pose of the surgical instrument relative to the end-effector based on the locations of the discrete features identified in the US imaging data, the processor is operative to match a spatial pattern of the locations of the discrete features identified in the US imaging data to content of a template for the surgical instrument which defines a pattern of the discrete features arranged around the surface of the surgical instrument as a function of locations along a length of the surgical instrument. In the example ofFIG.21A, the indentations2102are formed with alternating patterns2104aand2104balong a length of the shaft. Pattern2104aincludes a group of indentations2102which are circumferentially spaced around the shaft and spirally offset in a rotational direction along the length of the shaft. In contrast, pattern2104bincludes another group of indentations2102which are circumferentially spaced around the shaft and spirally offset in an opposite rotational direction along the length of the shaft relative to the pattern2104a. The processor can operate to match a spatial pattern of the locations of the discrete features identified in the US imaging data to content of a template for the surgical instrument which defines the alternating patterns2104aand2104b, to track the depth and rotation of the shaft relative to the guide tube2000. FIG.22depicts the surgical instrument2100ofFIG.21Aat three different depths and rotations relative to the guide tube2000. The pose of the surgical instrument2100relative to the guide tube2000is being detected by the US transducer2010. Because the indentations2102in the instrument shaft are at calibrated locations along the shaft and have a calibrated spatially shifting pattern that can be matched by the processor to a template, the surgical instrument's2100depth within the guide tube2000can be tracked using the US imaging data. As shown inFIG.22, the US signals emitted from each US transducer2010fan out and the indentations2102in the passing instrument surface reflect back US signals which are sensed by the US transducers2010and captured in the US imaging data output by the US transducers2010. In some other embodiments, the processor is operative to identify in the US imaging data locations of layers of materials of the surgical instrument, where adjacent layers of the materials have different reflectivity to US. The processor determines pose of the surgical instrument relative to the end-effector based on the locations of the layers of materials of the surgical instrument identified in the US imaging data. FIG.21Bdepicts a surgical instrument2110having a shaft with alternating layers of materials, e.g.,2112,2114,2112,2114, and so-on, stacked along a primary axis of the shaft, where adjacent layers2112and2114of the materials have different reflectivity to US. For example, layers2112may be substantially non-reflective to US and layers2114may be substantially reflective to US. In this manner, the differing reflectivity of the alternating layers2112and2114generates a pattern of US reflections which are identifiable in the US imaging data from the US transducer. The processor can track depth of the surgical instrument2110relative to the guide tube2100based on the pattern. The processor can count the stripes as they go by to determine depth or spacing between layers could be varied to provide a detectable depth pattern corresponding to different tool depth within a guide tube. FIG.21Cdepicts a surgical instrument2110having a shaft with alternating layers of materials, e.g.,2122,2124,2122,2124, and so-on, forming helical stripes spiraling about a primary axis of the shaft, where adjacent layers2122and2124of the materials have different reflectivity to US. For example, layers2122may be substantially non-reflective to US and layers2124may be substantially reflective to US. In this manner, the differing reflectivity of the alternating layers2122and2124generates a pattern of US reflections that are identifiable in the US imaging data from the US transducer. The processor can track depth and rotation of the surgical instrument2110relative to the guide tube2100based on the pattern. The processor can count the helix stripes as they pass by the US transducers or the pitch (stripes per cm) of the helix can be configured differently at different longitudinal positions to provide markers of specific depths. In another embodiment, a surgical instrument2110has a shaft with layers of materials forming stripes extending parallel to a primary axis of the shaft, where adjacent layers of the materials have different reflectivity to US. In this manner, the differing reflectivity of the alternating layers generates a pattern of US reflections which are identifiable in the US imaging data from the US transducer. The processor can track rotation of the surgical instrument relative to the guide tube2100based on the pattern. Some further embodiments are directed to using US imaging data from a US transducer in combination with at least one processor (“processor) to track pose of the robot end-effector relative to anatomical structure captured in an image volume for the patient. FIG.23depicts a flowchart of operations that can be performed by a processor to track pose of the end-effector relative to anatomical structure captured in an image volume based on US imaging data from a US transducer. Referring toFIG.23, the processor generates2300US images of the anatomical structure based on the US imaging data, and matches2302the anatomical structure captured in one of the US images to the anatomical structure captured in the image volume. The processor then determines2304the pose of the end-effector relative to the anatomical structure captured in the image volume based on the matching and the known orientation of the end-effector relative to the US transducers. Some further embodiments are directed to generating steering information based on the target pose for surgical instrument in a presently tracked pose of the end-effector relative to the anatomical structure captured in the image volume, such as according to the flowchart of operations depicted in the flowchart ofFIG.24. Referring toFIG.24, a processor is operative to determine2400a target pose for the surgical instrument based on a surgical plan defining where a surgical procedure is to be performed using the surgical instrument on the anatomical structure captured in the image volume. The processor is further operative to generate2402steering information based on the target pose for the surgical instrument and a present tracked pose of the end-effector relative to the anatomical structure captured in the image volume, the steering information indicating where the surgical instrument and/or the end-effector need to be moved. In a further embodiment, the processor is operative to control movement of at least one motor, which is operatively connected to move the robot arm relative to the robot base, based on the steering information to guide movement of the end-effector so the surgical instrument becomes positioned with the target pose FIG.25depicts a more detailed flowchart of operations and be performed by at least one processor (“processor”) to generate navigation information that can be used to guide movement of the robot end-effector toward a target pose, in accordance with some embodiments. Referring toFIG.25, the processor obtains2400a 3D MRI or CT image volume of the patient. The processor receives2402input from a surgeon who inputs a trajectory plan on anatomical structure captured in an image volume, or the surgical plan may be auto-generated by a surgical planning computer and or by the processor. For example, the surgeon may use an electronic pen to draw on a graphical representation of anatomical structure captured in the image volume to input the surgical trajectory. The robot arm is manually or automatically positioned2404by the processor so that the US transducer becomes in contact with the patient's skin surface. The processor registers2406(synchronizes coordinate systems) between coordinate systems of the US transducer, the robot, and the anatomical structure captured in the image volume. The processor displays2408a current pose (e.g., position and rotational orientation) of the end-effector, e.g., guide tube2000, relative to the anatomical structure captured in the image volume. The processor determines2410whether the end-effector is aligned with a target pose and, if so, the processor performs further operations2414associated with being on-target, such as tracking depth and rotation of a surgical instrument guided by the end-effector. In contrast, when the determination2410is that the end-effector is not aligned with the target pose, the processor generates2412navigation information computed to indicate a direction of movement as needed for the end-effector to reach the target pose and initiates further guided movement of the end-effector toward the target pose using the navigation information. In one embodiment, the US transducer must remain in contact with the patient's skin while moving so that the US imaging data from the US transducer continuously captures anatomical structure of the patient under the skin. A 6-axis load cell at or near the leading edge of the robot arm may be used to sense pressure of the US transducer and/or end-effector against the patient and ensure that the US transducer stays in gentle contact with the skin. As transitional robot movement occurs while traveling to the target pose, force feedback at the end-effector can be monitored from the load cell and robot arm angle and position can be responsively adjusted by the processor to maintain a light force on the skin surface while minimizing shear forces, such as described below with regard toFIGS.26A-C. The force feedback can also be utilized to ensure that, during this transitional movement, the US transducer remains normal to the skin surface to provide the clearest imaging of the anatomical structures in the US imaging data. FIGS.26A-Cdepicts a sequence of snapshots of a robotic arm104of the surgical robot system100moving laterally to a target pose while automatically maintaining contact between the US transducer2010and the patient's skin2600and normal to the body surface. Responsive to a leading edge of the guide tube2000reaching a trajectory at a target location, the processor can operate to automatically adjust the robot arm104so that the guide tube2000becomes oriented with a pose that matches the target trajectory. Optical tracking may be used to assist in localizing anatomical structure being imaged by a US transducer and to provide operational redundancy to take over when, for example, the US transducer ceases to contact the patient and therefore no longer outputs US imaging data of the anatomical structure. During a surgical procedure, the surgical robot system100may plan or predict a series of arm movements required to move from a current position to a new position with the expectation that the US transducer will lose contact with the patient's skin and, therefore, cease outputting US imaging data of the anatomical structure which is used for tracking location relative to the anatomical structure captured an image volume for the patient. It is further anticipated that the US transducer will eventually come back in contact with the skin again near a target location and therefore resume outputting US imaging data of the anatomical structure in a region near the target location. As with a continuous contact mode (e.g., where the US transducer maintains contact patient's skin), force feedback from one or more sensors can be used to interrupt controlled movement of the end-effector to ensure safe movement without unexpected collision with the patient or other obstacle. Processor operations can be configured to enter a “floating” mode in case of detected collision where the robot arm104is controlled to be easily moved in any direction with light applied force by a user and/or wait for user intervention. To clearly indicate to the user when the robot is in contact with the patient or is unable to determine pose based on US imaging data (e.g., US transducer has ceased contacting skin) and is estimating where the robot is based on the last known location, the surgical robot system100can be configured to display anatomical structure in different shades, such as grayscale, and/or different colors to visually differentiate between when the US transducer is properly contacting a patient to provide US imaging data that is being used to identify pose of the US transducer versus when the US transducer is not satisfying that condition. Displaying the anatomical structure in different shades and/or colors notifies the user when the displayed navigation information can be most accurately relied upon for precise navigation (i.e., when relying upon US imaging data of anatomical structure matching anatomical structure captured in the image volume) and when the navigation information is a rougher estimate (i.e., when not relying upon such US imaging data) but may still be useful for planning or non-surgical localization. In either of these modes (accurate or estimate), once the end-effector112control by the surgical robot102approaches the target location, the surgical robot102will adjust the arm104orientation to match the desired trajectory orientation while also monitoring feedback from the load cell. Load feedback would be used to adjust the end-effector112pose so that the desired orientation is achieved while maintaining constant low applied force between the US transducer and the patient's skin. During any phase of movement where the US transducer is in contact with the patient's skin, accuracy of the displayed information depends upon rapid re-registration (e.g., matching2302inFIG.23) of the anatomical structure captured in the US images generated (2300inFIG.23) based on the US imaging data to the anatomical structure captured an image volume for the patient. For example, the anatomical structure captured in a US image generated based on the US imaging data from the US detector is rapidly re-registered (matched2302inFIG.23) with the anatomical structure captured in the CT or MM scan volume so that the pose of the end-effector112(e.g., guide tube2000) relative to the patient's anatomical structure is known in near real time. For each of the US images, e.g., “frame”, which is generated based on the US imaging data, the US image is registered to the CT or MRI scan volume, providing an updated computed pose of the US transducer relative to anatomical structure captured in the scan (image) volume. Knowing the pose of the end-effector112(e.g., guide tube2000) relative to the US transducer and the pose of the anatomical structure captured in the CT or MRI scan volume relative to the US transducer, it is then possible to determine the pose of the end-effector112(e.g., guide tube2000) relative to the anatomical structure captured in the CT or MRI scan volume. The end-effector112(e.g., guide tube2000) can then be visualized by rendering a graphic representation of the end-effector112(e.g., guide tube2000) relative to (e.g., as a graphical overlay) the anatomical structure captured in the CT or MM scan volume. For clear visualization of the end-effector112(e.g., guide tube2000) relative to the anatomical structure, the scan volume can be displayed as a multiplanar reconstruction (MPR) view showing three mutually orthogonal slice views, two parallel and one perpendicular to the end-effector as is currently used in the Globus Excelsius GPS system. Registration of the pose of the US transducer to the CT volume may be computationally intensive and have relatively lower reliability if the registration is not initiated with direction or seeding to a carefully selected portion of the CT volume, such as if the registration operations attempted to look for a match across a large region of the CT volume. Therefore, the first registration may be computationally intensive or may require user intervention to achieve desired accuracy or successful completion. However, once the first registration has been completed, subsequent re-registrations can be performed with less computational resources needed because the system uses knowledge of exactly where the end-effector112(e.g., guide tube2000) has moved in its coordinate system via kinematics. When moving to a new target location, the system can assume that the patient anatomy is in a fixed location to get within a few millimeters of the target location and then focus the registration matching search to within a small range of the predicted target anatomy for a registration match between the structure of the anatomical structure captured in one of the US images to structure of the anatomical structure captured in the selected portion of the CT volume. The system can then refine its determination of the end-effector112(e.g., guide tube2000) pose and reach final alignment between target trajectory and end-effector112(e.g., guide tube2000) pose. In accordance with some further embodiments, the surgical robot system uses kinematic sensors on the robot, e.g., at pivot joints of the robot arms104and end-effector112, providing kinematic movement data to continue to track pose of the end-effector112during period while the US transducer is not outputting US imaging data of the anatomical structure, e.g., while the US transducer is lifted not in contact with the patient. The surgical robot system subsequently resumes using the US imaging data, and may cease any further concurrent use of kinematic movement data, when the US transducer has again contacted the patient and become re-registered to the CT volume or other image volume for the patient. In one embodiment, the surgical robot system includes kinematic sensors connected to the robot arm and which are operative to output kinematic movement data indicating change in pose of the robot arm relative to the robot base. The at least one processor (“processor”) is operative to, after tracking pose of the end-effector relative to the anatomical structure captured in the image volume based on the US imaging data for a period of time and responsive to the US transducer ceasing to output US imaging data of the anatomical structure proximately located to the end-effector, trigger continued tracking of the pose of the end-effector relative to the anatomical structure captured in the image volume based on the kinematic movement data. The processor is further operative to respond to the US transducer resuming output of US imaging data of the anatomical structure proximately located to the end-effector, by triggering continued tracking of the pose of the end-effector relative to the anatomical structure captured in the image volume based on the US imaging data. In a further related embodiment, the processor may cease tracking of the pose of the end-effector relative to the anatomical structure captured in the image volume based on the kinematic movement data, responsive to the US transducer resuming output of US imaging data of the anatomical structure proximately located to the end-effector. In a further related embodiment, the processor can be configured to constrain the search space for matching the anatomical structure captured in one of the US images to the anatomical structure captured in the image volume, based on a current pose tracked based on the kinematic movement data (position encoders at each robotic joint). The processor can operate to trigger continued tracking of the pose of the end-effector relative to the anatomical structure captured in the image volume based on the US imaging data, by operations which include generating US images of the anatomical structure based on the US imaging data, selecting a portion of the image volume based on a present pose of the end-effector as tracked relative to the anatomical structure captured in the image volume based on the kinematic movement data, and matching structure of the anatomical structure captured in one of the US images to structure of the anatomical structure captured in the selected portion of the image volume. The processor determines the pose of the end-effector relative to the anatomical structure captured in the selected portion of the image volume based on the matching. In some other related embodiments, the surgical robot system uses a different color and/or shading to visually indicate to a user when the tracking is performed based on US imaging data distinguished from when the tracking is performed based on kinematic movement data. In one embodiment, the processor is further operative to display a graphical representation of the end-effector with the determined pose relative to a graphical representation of the anatomy captured in the image volume. The processor uses a different color and/or shading to display the graphical representation of the end-effector relative to the graphical representation of the anatomy captured in the image volume to visually indicate to a user when the pose of the end-effector relative to the anatomical structure captured in the image volume is being tracked based on the US imaging data distinguishable by the user from when the pose of the end-effector relative to the anatomical structure captured in the image volume is being tracked based on the kinematic movement data. Some other embodiments are directed to using machine vision to ensure that the US transducer remains in contact with the patient's skin surface while the end-effector is moved to a target pose via a determined navigated pathway, and while avoiding collisions with other objects or body surfaces. The surgical robot system may further utilize machine learning in combination with machine vision. Visible light cameras could detect and map the surface of the patient's body and use a machine learning model, such as a neural network model, to determine an optimal pathway through which the end-effector is to be moved. For example, when moving across the spine from left to right, the computer operations can process the surface map and the starting and target locations through a machine learning model that has been trained on spinous (e.g., indicating that skin surface contours rise to a peak and then descend) and other body geometries to output a preferred navigation pathway for the end-effector to be moved to the target location. The robot movement would be responsively controlled for the end-effector and US transducer to rise-up and rotationally angle over the spine and then decline back down without having to rely solely on force feedback, thereby making the movement smoother and more reliable for maintaining desired contact between the US transducer and the patient's skin during the movement. Additionally, the prediction of how movement should occur can come from transducer feedback and fitting of the patient to a body model. For example, the US imaging data from the US transducer may be used to register the bony anatomy of the patient to an existing CT volume, but the CT volume may poorly capture the body surface. Accordingly, by fitting the patient's body to a computerized model that is based on age, gender, weight, ethnicity, etc. the body surface contours relative to the current location of the end-effector can be predicted and used when generating the preferred navigation pathway. In another embodiment, the surgical robot system operates using a combination of optical tracking input and US transducer input. In one embodiment, the surgical robot system only utilizes the US imaging data from the US transducer while the US transducer is close to a target location, e.g., where registration is performed with at least a threshold accuracy. All secondary transitional movement can be guided by optical feedback. For example, in some embodiments the surgical robot system switches from US tracking to optical tracking responsive to the US transducer ceasing to output US imaging data of the anatomical structure (e.g., losing contact with the patient). In one embodiment, the surgical robot system includes a tracking camera operative to track pose of markers on the robot arm and/or the end-effector. The at least one processor (“processor”) is operative to, after tracking pose of the end-effector relative to the anatomical structure captured in the image volume based on the US imaging data for a period of time and responsive to the US transducer ceasing to output US imaging data of the anatomical structure proximately located to the end-effector, trigger continued tracking of the pose of the end-effector relative to the anatomical structure captured in the image volume based on output of the tracking camera. The processor also responds to the US transducer resuming output of US imaging data of the anatomical structure proximately located to the end-effector, by triggering continued tracking of the pose of the end-effector relative to the anatomical structure captured in the image volume based on the US imaging data. In a further embodiment, the surgical robot system ceases tracking of the pose of the end-effector relative to the anatomical structure captured in the image volume based on output of the tracking camera. In another embodiment, the surgical robot system switches from optical tracking back to US tracking responsive to the US transducer resuming output of US imaging data of the anatomical structure (e.g., resuming contact with the patient). In one embodiment, the tracking camera operative to capture location of markers on the robot arm and/or the end-effector. The processor is operative to track pose of the markers. The processor, after tracking pose of the end-effector relative to the anatomical structure captured in the image volume based on the US imaging data for a period of time and responsive to the US transducer ceasing to output US imaging data of the anatomical structure proximately located to the end-effector, is operative to trigger continued tracking of the pose of the end-effector relative to the anatomical structure captured in the image volume based on output of the tracking camera. Responsive to the US transducer resuming output of US imaging data of the anatomical structure proximately located to the end-effector, the processor triggers continued tracking of the pose of the end-effector relative to the anatomical structure captured in the image volume based on the US imaging data. In a further embodiment, the surgical robot system ceases tracking of the pose of the end-effector relative to the anatomical structure captured in the image volume based on output of the tracking camera. Some further embodiments are directed to the surgical robot system initially using optical tracking to track pose of the end-effector while moving to a target region of the patient and then switching to tracking pose of the end-effector using US tracking and constraining the search space for the matching. In one embodiment, the surgical robot system includes a tracking camera operative to output optical tracking data indicating pose of a reference array on the robot arm and/or the end-effector and further indicating pose of a reference array at a defined location on the patient that is approximately correlated to a defined location in the anatomical structure captured in the image volume. The at least one processor (“processor”) is operative to track pose of the end-effector relative to the anatomical structure captured in the image volume based on the optical tracking data, while the end-effector is moved toward the patient for the US transducer to contact the patient. Responsive to the US transducer contacting the patient and beginning to output US imaging data of the anatomical structure proximately located to the end-effector, the processor generates US images of the anatomical structure based on the US imaging data. The processor selects a portion of the image volume based on a present pose of the end-effector as tracked relative to the anatomical structure captured in the image volume based on the optical tracking data, and matches structure of the anatomical structure captured in one of the US images to structure of the anatomical structure captured in the selected portion of the image volume. The processor determines the pose of the end-effector relative to the anatomical structure captured in the selected portion of the image volume based on the matching. In another related embodiment, the processor is operative to determine a target pose for the surgical instrument based on a surgical plan defining where a surgical procedure is to be performed using the surgical instrument on the anatomical structure captured in the image volume. The processor generates steering information based on the target pose for the surgical instrument and a present tracked pose of the end-effector relative to the anatomical structure captured in the image volume, the steering information indicating where the surgical instrument and/or the end-effector need to be moved. The pose of the end-effector relative to the anatomical structure captured in the image volume is tracked using the optical tracking data during a time period while the US transducer is not outputting US imaging data of the anatomical structure proximately located to the end-effector. In contrast, the pose of the end-effector relative to the anatomical structure captured in the image volume is tracked using the US imaging data and without using the optical tracking data during another time period while the US transducer is outputting the US imaging data of the anatomical structure proximately located to the end-effector. FIG.27depicts a flowchart of operations for controlling movement of the robot arm to a target pose using a combination of optical feedback control and US transducer feedback control, in accordance with some embodiments. Referring toFIG.27, the processor obtains2700a 3D MRI or CT image volume of the patient. The processor receives2702input from a surgeon who inputs a trajectory plan on anatomical structure captured in an image volume, or the surgical plan may be auto-generated by a surgical planning computer and or by the processor. For example, the surgeon may use an electronic pen to draw on a graphical representation of anatomical structure captured in the image volume to input the surgical trajectory. The processor performs coarse registration2704(synchronizes coordinate systems) between coordinate systems of the optical tracking system (e.g., tracking cameras200,326), the robot, and the anatomical structure captured in the image volume. The registration2704performed for optical tracking can be relatively roughly approximate while still being able to obtain successful navigated movement of the end-effector to a target pose. For example in a difficult case, if the registration2704has an error of several millimeters or is registered to the wrong level, the registration error is substantially reduced by further re-registration responsive to when the US images are generated from the US transducer (once the US transducer comes in skin contact) and structure of the anatomical structure captured in one of the US images is matched to structure of the anatomical structure captured in a selected portion of the image volume. Operations can therefore automatically adjust optical registration to continuously improve accuracy once US imaging data capturing anatomical structure of the patient is obtained from the US transducer. In the example operational flow, the robot arm is moved2706under optical tracking to be close to the target pose. Responsive to when the US imaging becomes activated, it is determined that the target pose is actually shifted to the left by 5 mm. Since the end-effector attached to the robot arm is tracked, the software would then immediately be able to update the optical-tracking-to-CT registration to synchronize with the newly found US-to-CT registration. For example, when the US imaging becomes activated and registration operations match structure of the anatomical structure captured in one of the US images to structure of the anatomical structure captured in the selected portion of the image volume, the operations being performing registration2708between coordinate systems of the US tracking system (e.g., US transducer), the robot, and the anatomical structure captured in the image volume. The operations can use the US based registration to improve accuracy of the earlier optical registration between coordinate systems of the optical tracking system (e.g., tracking cameras200,326), the robot, and the anatomical structure captured in the image volume through the registration operations2710using the determined registration between the US tracking system (e.g., US transducer) and the anatomical structure captured in the image volume. When initially preforming registration of the US transducer, the search region in the image volume can be selected based on the optical tracked location of end-effector. Because US registration is ultimately what is used to perform surgery and accuracy of the optical system is less important due to its lower accuracy and being prone to line-of-sight blockage, skin-mounted arrays tracked by the tracking cameras to simplify the entire registration and navigation process. Alternately, visible light tracking of the patient's body or of visible markings created on the patient's skin (e.g., using ink) provide adequately accurate optical tracking in this workflow. The processor displays2712a current pose (e.g., position and rotational orientation) of the end-effector, e.g., guide tube2000, relative to the anatomical structure captured in the image volume. The processor determines2714whether the end-effector is aligned with a target pose and, if so, the processor performs further operations2716associated with being on-target, such as tracking depth and rotation of a surgical instrument guided by the end-effector. In contrast, when the determination2714is that the end-effector is not aligned with the target pose, the processor generates2718navigation information computed to indicate a direction of movement as needed for the end-effector to reach the target pose and initiates further guided movement of the end-effector toward the target pose using the navigation information. Hybrid Patient Tracker Utilizing Optical Tracking and US for Noninvasively Tracking Patient Anatomical Structure As explained above, image-guided surgery often requires an invasive surgical process exposing bone to mount a patient reference tracker. Exposing the bone can lead to damage to the bone and soft tissues and infection. It is also time consuming to surgically clear a path to the bone. Some further embodiments of the present disclosure are directed to an anatomical structure tracker apparatus that includes both a US transducer and an optical tracking array. In some embodiments, the optical tracking array includes a plurality of spaced apart markers. The US transducer is rigidly coupled to and spaced apart from optical tracking array, and is operative to output US imaging data of anatomical structure. The optical tracking array may be configured as an array of, e.g.,3or4reflective optical markers that are tracked as a rigid body by a stereo camera tracking system. Or, the tracking array, which is combined with the US transducer, can be an electromagnetic sensor that electronically streams its 3D position within an electromagnetic field (e.g., Aurora by Northern Digital, Inc.). Additional options exist for tracking such as radiofrequency time-of-flight. The tracking array is mounted rigidly to an array of 1 or more US transducers. One problem with tracking the spine using camera optical tracking arrays is that the bone must be invasively exposed in order to temporarily attach an optical tracking array to the bone for monitoring movement of the bone, e.g., patient body movement. For example, the optical tracking array is typically attached to a spinous process clamp or to a spike that is driven into the ilium or other bony region near the surgical site. In contrast using an anatomical structure tracker apparatus in accordance with various present embodiments, it is possible to mount the optical tracking array on the skin surface and then to use US transducer rigidly affixed to the optical tracking array to determine pose of the optical tracking array relative to the bone. When the US tracking is performed continuously, the movement of the optical tracking array can be tracked in real time to improve tracking accuracy without requiring a rigid interconnection between the bone and the optical tracking array. FIG.28depicts an anatomical structure tracker apparatus that is configured in accordance with some embodiments. Referring toFIG.28, the apparatus includes an optical tracking array2810comprising a plurality of spaced apart markers2812. Apparatus further includes a two-dimensional planar array of US transducers2802, supported by a rigid base2800, and connected by a connecting arm to the optical tracking array2810. Each of the US transducers2802is configured to output US pulses and detect returned US reflections of the anatomical structure. Separation between the US transducers2802in the array may preferably be as small as possible to maximize resolution of the detected bone surface below the array. A US tracker computer2820, which may be part of the surgical robot system100, is configured to receive US imaging data from the US transducers and generate US images of the anatomical structure based on the US imaging data. The two-dimensional planar array of US transducers2802illustrated inFIG.28can be, for example, a 7×6 rectangular array of parallel linear US transducers2802. Each US transducer2802is capable of emitting US pulses and detecting reflected US. Operations for mounting the US transducers2802to skin could use adhesive gel, adhesive tape, elastic bands, or other means. As explained above, because of the ability to perform continuous monitoring of movement of the optical tracking array2810relative to US tracked anatomical structure, e.g., bone, it is not important for the apparatus to be rigidly mounted to bone and is only necessary that it be mounted so that the US transducers2802remain in contact with skin and the optical tracking array2810remains in range of and visible to the tracking cameras. Since US transducers generally require gel to conduct US waves from the skin to the probe, a layer of gel could be provided in a center portion of rectangular or ring-shaped adhesive grommets around each individual US transducer to adhere the US transducer to the skin surface. Alternately, gel could be provided in the center of a larger adhesive rectangular or ring-shaped grommet around the entire array of US transducers adhering the array to the skin surface while also maintaining a gel pocket between the skin and transducer. With the apparatus attached to the patient's skin, each US transducer can operate to detect underlying bone and detect the distance to the underlying bone according to the known speed of sound in the connective tissue below skin surface and dorsal to the vertebrae. With each parallel US transducer detecting the closest proximate contour of the underlying bone, a map of the bony surface could be generated by the US tracker computer2820. In some other related embodiments, instead of using an array of parallel linear US transducers, one or more “convex” or “sector” US transducers are used. These US transducers emit US pulses in a fan pattern. When utilizing more than one US transducer, some fan planes can be aligned perpendicular to others, such as shown inFIG.29. As with the linear array of US transducers, e.g., as shown inFIG.28, such an array would also be able to detect 3D location of bony prominences under the surface of the skin based on the known pattern and geometry of the fan planes, but would be able to detect bone over a wider region than the linear probe array. FIG.29depicts another anatomical structure tracker apparatus that is configured in accordance with some other embodiments. Referring toFIG.29, the apparatus includes the optical tracking array2810comprising the plurality of spaced apart markers2812. The apparatus further includes a US transducer having a linear array of US transducers2902each having a major axis and a minor axis, where the major axes of the US transducers in the linear array are parallel. The US transducer also has at least one pair of other US transducers2904spaced apart on opposite sides of the linear array of US transducers2902. Each of the US transducers2904in the at least one pair have a major axis and a minor axis, where the major axes of the US transducers2904in the at least one pair are parallel and extend in a direction that is substantially perpendicular to a direction of the major axes of the US transducers2902in the linear array. A US tracker computer2820, which may be part of the surgical robot system100, is configured to receive US imaging data from the US transducers2902and2904and generate 3D US images of the anatomical structure based on the US imaging data. The US transducers2902and2904are mounted to a base plate2900. In the example ofFIG.29, linear array of US transducers2902has 8 convex US transducers which are oriented such that the planes of the fan pattern of emitted US waves from the US transducers2902are parallel and are oriented along a first axis of the base plate. There are also two pairs of US transducers2904spaced apart on opposite sides of the linear array of US transducers2902, and which are oriented such that the planes of the fan pattern of emitted US waves from the US transducers2904are oriented along another a second axis of the base plate which is perpendicular to the first axis. The fan-shaped planes of US pulse emission are illustrated inFIG.29for two of the eight US transducers. As an alternate to either of the US transducers configurations illustrated inFIGS.28and29, any 3D US transducer can be used to identify 3D locations of detected structures relative to the optical tracking array2810. With the surface of a vertebra mapped according using the US transducer(s), the US tracker computer can track movement of the vertebra. In one embodiment, the bony structures detected by US transducer can be treated as natural fiducials. That is, a bony prominence that has a unique structure such as an outcropping or dimple can be identified automatically and then followed from frame to frame of US images generated based on the US imaging data, to keep track of the bone relative to the optical tracking array. If three or more such natural fiducials are identified and followed, there is enough data to compute full rigid body movement of the bone under the skin according to known operations. In this embodiment, the system does not have any information on what part of the anatomy is being imaged, it is simply using the bone as a rigid fixed reference. Therefore, when the patient is in a particular position such as the position at which registration is recorded, the natural fiducials can be considered to be at their zero location. Any movement of the natural fiducials relative to the US transducer can be tracked essentially by detecting the natural fiducial's x, y, z location from the linear US transducer. Then at any given frame of tracking data containing both optical tracking and US tracking, the vertebra position is the hybrid (optical and US) anatomical structure tracker apparatus position as detected by the optical data plus the offset as detected based on the US imaging data. In another embodiment for tracking movement of the vertebra, the US imaging data is used for registration instead of only being used to follow natural fiducials. That is, the contours of the bony surface as detected by the US transducer are matched against the known bony contours from another medical image such as a CT scan. Bony contours in the CT or MRI image volume are detected using image processing edge detection algorithms. The medical image becomes registered to the tracker as soon as a unique match between bone contours detected by US and bone contours detected in the medical image volume is determined. That is, when the system identifies a contour match, the transformation to get from the medical image coordinate system to the hybrid (optical and US) anatomical structure tracker apparatus coordinate system becomes known. Since the US transducer is in a known position relative to the optical tracking array, i.e., through the rigid coupling therebetween, the camera coordinate system and the CT coordinate system are then co-registered. Thus, the hybrid anatomical structure tracker apparatus serves not only as a non-invasive patient reference array, but also as a means of registration. By using this registration method, no x-rays or additional ionizing radiation are needed to achieve registration. The workflow for using the hybrid anatomical structure tracker apparatus in registration and tracking could be as follows, and according to some embodiments. First, the patient receives a 3D scan such as a MRI or a CT scan. Then, in the operating room, a hybrid anatomical structure tracker apparatus is adhered to the skin, superficial to the spine level to be operated, with a layer of gel captured between the US transducer the skin. The US transducer is activated, detecting the bones underneath and generating a surface contour map. An algorithm then compares the surface contours as detected from the US transducer to the contours found on the preoperative MM or CT scan, iteratively comparing different regions at different orientations until a match is found. Once a match is found, registration has been achieved between medical image volume and the optical/electromagnetic/radiofrequency tracking coordinate system and other tools such as drills, probes, and screwdrivers can be tracked and images of the tools overlaid on the MRI or CT volume as is commonly done with surgical navigation. After registration, the hybrid anatomical structure tracker apparatus remains in place and serves as a patient tracker, accurately tracking the location of bone by combining optical tracking data with US tracking data. In some cases, the hybrid anatomical structure tracker apparatus may become obtrusive to the surgeon if it is located directly over the site at which surgery is being performed. In such cases, the hybrid anatomical structure tracker apparatus can be used to register the level of interest and additional similar trackers could be placed nearby over regions that are less obtrusive but still relatively close to the surgical site. After registration is established with the primary device, the transformation between the secondary tracker(s) and primary tracker can be recorded (“registration transfer” as described elsewhere) and then the primary tracker removed. This method assumes that any movement of bone at the location where the primary tracker was mounted would result in equivalent movement of bone at the region where the secondary tracker is mounted. In cases where large bending of the spine may occur, a secondary tracker rostral to the primary site and a tertiary tracker caudal to the primary site could be used and the movement at the primary site calculated as the average of the secondary and tertiary movements. It may be undesirable to apply US continuously for a long period to the patient. The skin-mounted device could therefore function in different modalities. When needed for registration, the device could apply continuous energy. When monitoring location, the device could pulse intermittently as needed, for example one 100 ms pulse every 2 seconds. Other factors may also be used to trigger when a higher frequency of sampling is needed. For example, if tracking cameras detect acceleration or movement exceeding some threshold, the system could be put into continuous sampling mode until movement ceases. Additionally, if a US pulse detects movement beyond some threshold of the last position, the monitoring algorithm could trigger the system to switch to continuous sampling mode until movement ceases. Finally, an additional sensor such as an accelerometer sensing movement of the apparatus or pressure sensor sensing a change in pressure of the gel chamber could trigger the system to enter continuous sampling mode until a stable state is reached again. Monitoring Sensitive Anatomical Structures During Spine Surgery In minimally invasive spine surgery (MIS), sequential dilation is used to gain access from an incision to a surgical target, typically the intervertebral disc space. During dilation the surgeon must monitor the location of sensitive structures, such as nerves, veins, and arteries, in order to avoid serious complications caused by compromising those structures. The specific structures are dependent on the anatomy traversed in a given approach. The sensitive structures of common approaches are described below. In MIS transforaminal lumbar interbody fusion (TLIF), the intervertebral disc space is commonly accessed through Kambin's Triangle, an anatomical corridor defined by the triangular shape formed by the exiting nerve root, traversing nerve root, and superior vertebral end plate. The surgeon uses this corridor as a safe access space to perform the discectomy and place the interbody device. Accurate targeting of this corridor is crucial to avoid damage to the adjacent nerves. In lateral lumbar interbody fusion (LLIF), the disc space is commonly accessed through a retroperitoneal approach where the dilator is placed posterior to the peritoneum and traversed through the psoas muscle. In this approach, the disc space must be accurately targeted without violating the peritoneum and lumbar plexus. The sensitive anatomical structures are typically monitored through direct visualization and/or intraoperative neuromonitoring. Direct visualization involves creating a clear line of sight between the structure and the surgeon's eyes. This approach typically requires a larger incision and access corridor, which is in opposition with benefits of minimally invasive surgery. Intraoperative neuromonitoring is used to identify real-time damage or insult to nerves by monitoring the electrical activity of the nervous system. Stimulated electromyography (EMG) is a common neuromonitoring modality employed for monitoring the proximity of or irritation to individual nerve roots associated with motor function during spine surgery. The system monitors the change in nerve activity relative to an established baseline. In some systems, the status is reported as color indicators which represent grades of change. Less than 100 mA change is reported as a green indicator, greater than 100 mA change is reported as a yellow indicator, and the lack of a response is indicated as a red indicator. This information is limited as it communicates a relative, quantitative status and does not provide intuitive visualization of the nerve location. In addition, neuromonitoring is limited to monitoring nerve activity and is not capable of monitoring blood vessels. Various further embodiments of the present disclosure are directed to detecting and providing user notification of the location of nerves, blood vessels, and other sensitive structures using intraoperative US imaging. Detecting these structures with US enables the surgeon to be aware of the structure and its location while accessing the disc space in a minimally invasive approach, rather than relying on larger incisions as in direct visualization or relative status information as in neuromonitoring. Further embodiments are directed to US transducer apparatuses and operations for detecting blood vessels with traditional and navigated access instruments capable of US imaging. One US imaging modality for non-invasive visualization of anatomical structures, includes nerves and blood vessels. One such application is US guided nerve block, where US is used to identify the target nerve and guide the needle placement. Another application is the use of Doppler US to measure the amount of blood flow through veins and arteries. Doppler US may be coupled with US guided nerve block to monitor the position of a critical vein or artery while the needle is placed. Machine learning can be implemented to generate 3D models from US scans and to measure and visualize bladder volume. US transducers are available in a variety beam shapes. Traditional handheld US transducers are most commonly convex or linear. Convex transducers contain a curved array of piezoelectric transducers that emit and receive US signals in a convex beam shape. Similarly, linear transducers contain a linear array of transducers that emit and receive signals in a linear beam shape. Endoscopic transducers are significantly smaller, approximately 2 mm in diameter, for use in endoscopic or endobronchial applications. These probes can be provided with convex and radial beam shapes. In endobronchial US (EBUS) lung biopsy applications, the radial EBUS probe spins to generate a radial beam shape and is used locate the tumor in the bronchial tube. The convex EBUS probe is then used to target the tumor with the biopsy needle. Some embodiments are directed to US transducer apparatuses and operations for visualizing sensitive structures in spine surgery by combining US imaging with traditional and navigated spine access instrumentation. These embodiments may replace or supplement neuromonitoring by providing the surgeon the ability to visualize the location of nerves relative to instrumentation rather than solely depending on relative indicators (i.e. red, yellow, green). The application of US Doppler imaging, which can identify fluid movement, can also be used to provide the surgeon the ability to visualize the location of veins and arteries relative to instrumentation. In addition, machine learning may be implemented to compute 3D models of spine anatomy, including discectomy volume. Each of the modalities may be combined with navigation to register and augment the US image with CT, MM or fluoroscopic images. In one embodiment of the present disclosure, a US transducer apparatus includes a support wire and a US transducer attached to an end of the support wire. The support wire may be a rigid support wire, such as a “Kirschner wire” or “K-wire” probe. The US transducer may be one of a convex US transducer, a radial US transducer, and a linear US transducer. An interface is provided for communicating US data through a flexible signal wire, which may extend through the support wire, to a computer configured to process the US data. The computer may be configured to process the US data to generate a graphical representation of anatomical structure sensed by US signals emitted by the US transducer. Alternatively or additionally, the computer may be configured to process the US data to identify nerves and/or blood vessels within the anatomical structure sensed by US signals emitted by the US transducer. The computer includes at least one processor and circuitry configured to drive the US transducer to generate US signal emissions and to condition the return US signals received by the US transducer for processing by the at least one processor. In spine surgery, long rigid wires, commonly called “Kirschner wires” or “K-wires”, are used to probe anatomy and guide instruments and implants to the anatomical targets. K-wires are typically guided to the target using fluoroscopic imaging. Once the K-wire is placed, larger profile instruments or implants are guided over the K-wire, which is typically anchored in the anatomy. For example, K-wires are used to guide cannulated pedicle screws safely through the pedicle trajectory. K-wires are also commonly inserted into the intervertebral disc and used to guide sequential dilators and maintain the position of the dilator relative to the disc during retractor or port placement. Various embodiments the present disclosure may remove the need for or supplement fluoroscopy by allowing the surgeon to monitor the location of nerves and blood vessels while guiding the K-wire into position. The present wire-like US transducer apparatus and the operationally coupled computer are configured to provide visualization of the position of anatomical structures through 2D US imaging, identifying nerves and blood vessels apart from other anatomy, identifying blood flow using US Doppler imaging, and constructing 3D models of anatomical structures including discectomy volume using 3D US imaging. As described above, a flexible signal wire is used to transfer the US data (e.g., US wave signals) to a computer for processing. The support wire can be flexible to facilitate tip positioning during a procedure. In some embodiments, a wireless communication interface may be provided between the US transducer and the computer, thereby eliminating or reducing the length of the flexible signal wire extending between the US transducer and a wireless transmitter. In one embodiment, a processor is mounted on the proximal end of the support wire and coupled to the US transducer to receive US data and further coupled to a wireless transmitter to transmit the US data to the computer. As used herein, US data may be an analog US signal or digital representation thereof. The US transducer, the processor, and the wireless transmitter may be powered by a proximally located battery. A machine learning model may be used to process the US data to identify specific types of anatomical structures. The machine learning model may be a neural network or other computer algorithm that is trained to identify the US reflection appearance of specific types of anatomical structures. The machine learning model may be trained to differentiate among learned US reflection appearances of different types of anatomical structures, which may be obtained a database, to identify which type of anatomical structure is likely the source of the observed US reflection. The machine learning model can be trained using data characterizing US reflection appearances of known anatomical structures, which could be provided through computational modeling of the anatomical structures or through expert US users labeling the anatomical structures in US images generated from US data. The US transducer apparatus may require rotation during a surgical procedure. Rotation at the tip may be manually applied by rotating the entire apparatus or rotating a mechanism at the base of the apparatus that extends within the support wire, e.g., with rotation of the US transducer occurring within a sheath across a bearing surface. Alternately, US transducer rotation may be provided using a miniature motor mounted near the tip of the support wire, between the support wire and the US transducer, that is powered using, e.g., electrical wires that traverse the shaft alongside the US signal wires. FIG.30depicts a US transducer apparatus which includes a support wire3000connected to a convex US transducer3002which communicates US image data through a flexible signal wire3004to a computer, in accordance with some embodiments.FIG.30also depicts another US transducer apparatus which includes a support wire3010connected to a radial US transducer3012which communicates US image data through a flexible signal wire3014to a computer, in accordance with some embodiments. FIG.31depicts another embodiment of a US transducer apparatus3100which includes a support wire (which may be similar to a “K-wire”), which is temporarily inserted through a dilator (Cannula)3104having an inner void through which the support wire extends and can be removed. The apparatus further includes a convex US transducer3102attached to a distal tip of the support wire and/or the cannulated dilator3104. A flexible signal wire3106or other communication interface carries the US data from the US transducer3102to the computer. FIG.31also depicts another embodiment of a US transducer apparatus3110which includes a support wire (which may be similar to a “K-wire”), which is temporarily inserted through a dilator (Cannula)3114having an inner void through which the support wire extends and can be removed. The apparatus3110further includes a radial US transducer3112attached to a distal tip of the support wire and/or the cannulated dilator3114. A flexible signal wire3116or other communication interface carries the US image data from the US transducer3112to the computer. These removable US transducer apparatuses3102,3112can be connected to the computer configured to generate the graphical visualizing of the position of anatomical structures since using ultrasound, to identify nerves and blood vessels apart from other anatomy (which may use machine learning), to identify blood flow using Doppler imaging, and to construct 3D models of anatomical structures including discectomy volume. The US transducers3102,3112may be attached to the cannulated dilator3104,3114through various mechanisms, including threads, friction, magnets, clamps, etc. The attachment mechanism can include a bearing surface or sheath to allow the US transducers3102,3112to rotate during imaging as required for radial transducers. A potential advantage of one or more of these embodiments is that a US transducer apparatus is provided that can be inserted by a surgeon using a surgical procedure developed for rigid wires, such as K-wires. FIG.32illustrates another US transducer apparatus3200configured in accordance with some embodiments. The US transducer apparatus3200includes a dilator (Cannula)3214containing a permanent integrated rigid wire, which may be similar to a “K-wire”. The apparatus3200further includes a convex US transducer3212attached to a distal tip of the cannulated dilator3214. A flexible signal wire3216or other communication interface carries the US data from the US transducer3212to the computer. The computer may be configured to process the US data to generate graphical visualization of the position of anatomical structures, identify nerves and blood vessels apart from other anatomy using machine learning, identify blood flow using Doppler imaging, and construct 3D models of anatomical structures including discectomy volume. FIG.33illustrates another US transducer apparatus3300configured in accordance with some embodiments. The US transducer apparatus3300includes a dilator (Cannula)3314containing a permanent integrated rigid wire, which may be similar to a “K-wire”. The apparatus3300further includes a convex US transducer3312is attached to the dilator3314through a bearing3314or sheath which allows rotation of the US transducer3312relative to the dilator3314. A flexible signal wire3316or other communication interface carries the US data from the US transducer3312to the computer. The computer may be configured to process the US data to generate graphical visualization of the position of anatomical structures, identify nerves and blood vessels apart from other anatomy using machine learning, identify blood flow using Doppler imaging, and construct 3D models of anatomical structures including discectomy volume. FIG.34depicts a US transducer apparatus which includes a support wire3400and a convex US transducer3402connected to the support wire3400. The convex US transducer3402is operable to communicate US data through a flexible signal wire3406to a computer. In accordance with some embodiments, an optical tracking array3404comprising a plurality of spaced apart markers is attached to the support wire3400at a location spaced apart from the convex US transducer3402. FIG.34also depicts another US transducer apparatus which includes a support wire3410and a radial US transducer3412connected to the support wire3410. The radial US transducer3412is operable to communicate US data through a flexible signal wire3416to a computer. In accordance with some embodiments, an optical tracking array3414comprising a plurality of spaced apart markers is attached to the support wire3410at a location spaced apart from the radial US transducer3412. By integrating an optical tracking array into the US transducer apparatus, the US transducer pose may be tracked using a surgical navigation system. Tracking pose of the US transducer enables the processor to computationally merge the US image with the primary navigation image, such as CT, MRI, or fluoroscopy. Navigation also allows the US transducer to be graphically represented relative to the primary navigation image. In addition, by using the optical tracking array to track the US transducer the computer can be configured to generate 3D US images. 3D US images can be used as the stand-alone navigation image or could be used to update the registration of the primary navigation image. Updating registration is useful because the US transducer apparatus itself can alter the configuration of anatomical structures through normal pressure applied, reducing accuracy of primary rigid body navigation. Even if the US transducer apparatus causes changes to the deep anatomy relative to the surface, by providing a rough location within the image volume of the tool tip, it is computationally easier to find a match of the US image contours to the CT or MRI image contours within the search area defined by navigation than if the entire image volume is searched. Finally, integrating navigation is useful because tracking the US transducer during US scanning facilitates measuring volumes from the 3D US images. For example, it would be possible to measure the size of tumors or the extent of a discectomy. The following embodiments build on those described above with the addition of optical tracking arrays, which may be detachable or permanently fixed to the US transducer apparatus. FIG.35depicts a US transducer apparatus3500which includes a support wire3503extending from a flexible signal wire3508through a dilator3504to connect to a convex US transducer3502. The convex US transducer3502is operable to communicate US data through the flexible signal wire3508to a computer. In accordance with some embodiments, an optical tracking array3506comprising a plurality of spaced apart markers is attached to the support wire3503at a location spaced apart from the convex US transducer3502. FIG.35also depicts another US transducer apparatus3510which includes a support wire3513extending from a flexible signal wire3518through a dilator3514to connect to a radial US transducer3512. The radial US transducer3512is operable to communicate US data through the flexible signal wire3518to a computer. In accordance with some embodiments, an optical tracking array3516comprising a plurality of spaced apart markers is attached to the support wire3513at a location spaced apart from the convex US transducer3512. FIG.36depicts another US transducer apparatus3610which is permanently integrated into a dilator3614connected to a convex US transducer3612. The convex US transducer3612is operable to communicate US data through a flexible signal wire3618to a computer. In accordance with some embodiments, an optical tracking array3616comprising a plurality of spaced apart markers is attached to the dilator3614at a location spaced apart from the convex US transducer3612. FIG.37depicts another US transducer apparatus3700which is permanently integrated into a dilator3714connected to a radial US transducer3712through a bearing3713which allows rotation of the radial US transducer3712relative to the dilator3714. The radial US transducer3712is operable to communicate US data through a flexible signal wire3718to a computer. In accordance with some embodiments, an optical tracking array3716comprising a plurality of spaced apart markers is attached to the dilator3714at a location spaced apart from the radial US transducer3712. Some embodiments of US transducer apparatuses described above have utilized rigid dilators and support wires. In some other embodiments the support wire and dilator are flexible to allow curvature during surgical procedures. Allowing curvature can allow more adaptable positioning to reach certain anatomical structures, such as the underside of ribs, while still being trackable using a combination of US and optical tracking. FIG.38depicts a US transducer apparatus3800which includes a dilator or semi-rigid tube3814connected to a radial US transducer3812through a bearing3813which allows rotation of the radial or convex US transducer3812relative to the dilator3814. The radial or convex US transducer3812is operable to communicate US data through a flexible signal wire3818to a computer. In accordance with some embodiments, an optical tracking array3816comprising a plurality of spaced apart markers is attached to the dilator3814at a location spaced apart from the radial US transducer3812. Positional tracking of the tip of the US transducer3812can be performed using a sensor that senses the position of the dilator without relying on a rigid extension to extrapolate the tip position from the optical tracking array3816. Some embodiments track the tip of the US transducer3812connected to the flexible dilator3814using electromagnetic tracking, radiofrequency time-of-flight tracking, or fiber-optic tracking to augment optical tracking of the optical tracking array3816. In one embodiment, a fiber optic element extends down a length of the flexible dilator or tube3814or other flexible support wire connected to the US transducer3812, and is configured to sense variation in curvature of the flexible dilator or tube3814or other flexible support wire. The fiber optic element may include a Fiber Bragg Grating sensor (FBGS)3820configured to sense variation in curvature of the flexible dilator or tube3814or other flexible support wire. The fiber optic element can be configured to communicate curvature sensing data through the flexible signal wire3818to the computer which is configured to track location of the fiber optic element. In a further embodiment which uses fiber-optic tracking to augment optical tracking, a fiber-optic element such as a FBGS element extends down the length of the probe alongside the US signal wires. Using methods described for FBGS, the bending of the flexible dilator3814to track the tip position and, thereby, the proximal position of an attached US transducer3812. After registration of tracking to MM or CT image volume, the processor can be configured to navigate the US transducer3812within the body, approximating where within the MM or CT image volume the tip is located. Because the tissue pathway within the body deforms in response to pressure from the US transducer3812and flexible dilator3814, the position would not be exact. However, the processor can use a shape-matching algorithm to determine which anatomical structures from the MM or CT are being imaged by the US transducer3812, further refining the navigated probe tip location accuracy. Further Definitions and Embodiments In the above-description of various embodiments of present inventive concepts, it is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of present inventive concepts. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which present inventive concepts belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense expressly so defined herein. When an element is referred to as being “connected”, “coupled”, “responsive”, or variants thereof to another element, it can be directly connected, coupled, or responsive to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected”, “directly coupled”, “directly responsive”, or variants thereof to another element, there are no intervening elements present. Like numbers refer to like elements throughout. Furthermore, “coupled”, “connected”, “responsive”, or variants thereof as used herein may include wirelessly coupled, connected, or responsive. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Well-known functions or constructions may not be described in detail for brevity and/or clarity. The term “and/or” includes any and all combinations of one or more of the associated listed items. It will be understood that although the terms first, second, third, etc. may be used herein to describe various elements/operations, these elements/operations should not be limited by these terms. These terms are only used to distinguish one element/operation from another element/operation. Thus, a first element/operation in some embodiments could be termed a second element/operation in other embodiments without departing from the teachings of present inventive concepts. The same reference numerals or the same reference designators denote the same or similar elements throughout the specification. As used herein, the terms “comprise”, “comprising”, “comprises”, “include”, “including”, “includes”, “have”, “has”, “having”, or variants thereof are open-ended, and include one or more stated features, integers, elements, steps, components or functions but does not preclude the presence or addition of one or more other features, integers, elements, steps, components, functions or groups thereof. Furthermore, as used herein, the common abbreviation “e.g.”, which derives from the Latin phrase “exempli gratia,” may be used to introduce or specify a general example or examples of a previously mentioned item, and is not intended to be limiting of such item. The common abbreviation “i.e.”, which derives from the Latin phrase “id est,” may be used to specify a particular item from a more general recitation. Example embodiments are described herein with reference to block diagrams and/or flowchart illustrations of computer-implemented methods, apparatus (systems and/or devices) and/or computer program products. It is understood that a block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by computer program instructions that are performed by one or more computer circuits. These computer program instructions may be provided to a processor circuit of a general purpose computer circuit, special purpose computer circuit, and/or other programmable data processing circuit to produce a machine, such that the instructions, which execute via the processor of the computer and/or other programmable data processing apparatus, transform and control transistors, values stored in memory locations, and other hardware components within such circuitry to implement the functions/acts specified in the block diagrams and/or flowchart block or blocks, and thereby create means (functionality) and/or structure for implementing the functions/acts specified in the block diagrams and/or flowchart block(s). These computer program instructions may also be stored in a tangible computer-readable medium that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable medium produce an article of manufacture including instructions which implement the functions/acts specified in the block diagrams and/or flowchart block or blocks. Accordingly, embodiments of present inventive concepts may be embodied in hardware and/or in software (including firmware, resident software, micro-code, etc.) that runs on a processor such as a digital signal processor, which may collectively be referred to as “circuitry,” “a module” or variants thereof. It should also be noted that in some alternate implementations, the functions/acts noted in the blocks may occur out of the order noted in the flowcharts. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality/acts involved. Moreover, the functionality of a given block of the flowcharts and/or block diagrams may be separated into multiple blocks and/or the functionality of two or more blocks of the flowcharts and/or block diagrams may be at least partially integrated. Finally, other blocks may be added/inserted between the blocks that are illustrated, and/or blocks/operations may be omitted without departing from the scope of inventive concepts. Moreover, although some of the diagrams include arrows on communication paths to show a primary direction of communication, it is to be understood that communication may occur in the opposite direction to the depicted arrows. Many variations and modifications can be made to the embodiments without substantially departing from the principles of the present inventive concepts. All such variations and modifications are intended to be included herein within the scope of present inventive concepts. Accordingly, the above disclosed subject matter is to be considered illustrative, and not restrictive, and the appended examples of embodiments are intended to cover all such modifications, enhancements, and other embodiments, which fall within the spirit and scope of present inventive concepts. Thus, to the maximum extent allowed by law, the scope of present inventive concepts are to be determined by the broadest permissible interpretation of the present disclosure including the following examples of embodiments and their equivalents, and shall not be restricted or limited by the foregoing detailed description.

11857274

DETAILED DESCRIPTION In this specification, reference is made in detail to specific embodiments of the invention. Some of the embodiments or their aspects are illustrated in the drawings. For clarity in explanation, the invention has been described with reference to specific embodiments, however it should be understood that the invention is not limited to the described embodiments. On the contrary, the invention covers alternatives, modifications, and equivalents as may be included within its scope as defined by any patent claims. The following embodiments of the invention are set forth without any loss of generality to, and without imposing limitations on, the claimed invention. In the following description, specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may be practiced without some or all of these specific details. In addition, well known features may not have been described in detail to avoid unnecessarily obscuring the invention. As shown inFIG.1, an embodiment of a localizer (or a sheath as described herein) may have a main tubular body100and a code platform102. The code platform102may include one or more codes104,106. In some embodiments, the codes104,106may be different hamming codes. A padding108may further be disposed on the code platform102. For example, the padding108may border one or more edges of each of the codes104,106on the code platform102. The one or more codes104,106may be composed of a non-reflective material that absorbs light. As such, various embodiments of the physical instrument may be tracked by a visible light camera, thereby alleviate the requirement of utilizing an infrared tracking system typically found in conventional systems. In some embodiments, the physical instrument may be composed of a plastic nylon material, stainless steel or aluminum. In some embodiments, the physical instrument may be a medical instrument with a composition that includes a sterilized material, such as a material sterilized via gamma-sterilization or auto-clave. As shown inFIG.2, the code platform102may have a top surface114. The top surface114may include a first fiducial marker region116and a second fiducial marker region118. It is understood that, in various embodiments, the first and second fiducial marker regions116,118may be the one or more codes104,106—respectively. A portion of the code platform102that includes the first fiducial marker region116may be disposed on the localizer such that region116is parallel to the main tubular body100. The main tubular body100may have a first terminal portion110and a second terminal portion112. The code platform102may be connected to the first terminal portion110. The second fiducial marker region118may be angled towards the first terminal portion110such that a degree amount150that is greater than 180 exists between the respective fiducial marker regions116,118. In various embodiments, the tubular body100may have one or more measurement markings representing distance from the tip. As shown inFIG.3, a bottom surface120of the code platform102may be connected to the first terminal portion110. As shown inFIG.4, the second terminal portion112may include a tapered tubular segment122. The tapered tubular segment122may further include a flat tip124of the main tubular body100. As shown inFIG.5, the main tubular body100may include a tubular segment126and one or more tapered tubular segments122,122-1,122-2. It is understood that all of the tapered tubular segments122,122-1,122-2illustrated inFIG.5may be interpreted as each being a respective part of a single tapered tubular segment that is adjacent to the tubular segment126. The tapered tubular segment122may have a first segment portion with a first diameter that is larger than a second diameter at a second segment portion, whereby the second diameter is substantially similar to a diameter of the flat tip124. FIGS.6-7each illustrate a hand position for holding an embodiment of the localizer. It is understood that while various portions and/or segments of the physical instrument are described herein as having a tubular shape(s). Various embodiments of the physical instrument are not restricted or limited to only having tubular portions and/or tubular segments. As shown inFIG.8, an embodiment of the localizer may include a main tubular body200. The main tubular body200may have a first terminal portion210and a second terminal portion212. The second terminal portion212may and in a flat tip224. A code platform202may be proximate to the first terminal portion210. The code platform202may have a top surface that includes one or more codes204,206and a padding208that surrounds and borders the respective edges of the codes204,206. The one or more codes204,206may be angled away from the main tubular body200. For example, each code204,206may be a respective fiducial marker region disposed on the top surface214of the code platform202. As shown inFIG.8, wherein the localizer is oriented in a vertical position with the code platform202above the flat tip224, the code platform202may be shaped according to a “V” formation such that a central portion of the code platform202is attached to the first terminal portion210and a degree amount250that is less than 180° exists between the fiducial marker regions on the top surface214. In other embodiments, the degree amount250may be larger than 180°, to result in an “upside down V” formation. As shown inFIG.9, the code platform202may have a bottom surface220that is attached to the first terminal portion210.FIGS.10-11each illustrate a hand position for holding an embodiment of the localizer.FIG.10provides a perspective view directly above the top surface214of the code platform202resulting from the hand position for holding the localizer.FIG.11provides a perspective side view of the localizer resulting from the hand position for holding the localizer. As shown inFIG.12, an embodiment of a sheath may include a main tubular body300. The main tubular body300may include a first terminal portion310and a second terminal portion312. An arm350may extend perpendicularly away from the main tubular body300. The arm350may be attached to the main tubular body300proximate to the first terminal portion310. The arm350may be connected to a code platform302. The code platform302may have a top surface314upon which one or more codes304,306are disposed. The top surface314may have a padding308that surrounds the respective codes304,306and borders the respective codes304,306. The one or more codes304,306may be angled downwards and towards the direction of the second terminal portion312. The main tubular body300may include a first opening of internal passage360that extends from an edge of the first terminal portion310to an edge of the second terminal portion312. As shown inFIG.13, a second opening of the internal passage360-1may be included at the edge of the second terminal portion312. As the codes304,306on the top surface314are angled away from each other, a degree amount370less than 180° exists between a first portion of the bottom surface320and a second portion of the bottom surface320. In other embodiments, the degree amount250may be larger than 180°, whereby the code platform302comprises a “V” formation. As shown inFIG.14, the arm350connects the code platform302to the main tubular body300. An internal passage extends throughout and within the main tubular body300. The internal passage is accessible via openings360,360-1at terminal portions of the main tubular body300. The main tubular body300further includes a tapered tubular segment322and a tubular segment326. The tapered tubular segment322includes the flat tip324. A first diameter328of the tapered tubular segment322may be equal to a diameter of a portion of the first tubular segment326. A second diameter330of the tapered tubular segment322may be a diameter of the flat tip itself324. A particular passage opening360-1may be accessible at the flat tip324. FIG.15provides a perspective side view of a hand position for holding the sheath. In the foregoing disclosure, implementations of the disclosure have been described with reference to specific example implementations thereof. It will be evident that various modifications may be made thereto without departing from the broader spirit and scope of implementations of the disclosure as set forth in the following claims. The disclosure and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.

11857275

DETAILED DESCRIPTION Mental health conditions and other neurological problems are a significant field of medicine with profound importance for both patients and society as a whole. For example, depression and suicidal ideation represent chronic public health issues. However, treatment for these conditions have conventionally been addressed with pharmaceuticals, and in some treatment resistant cases, using surgery and/or electroconvulsive therapy (ECT). These methods can have significant side effects that are both mental and physical. In contrast, a form of therapy called transcranial magnetic stimulation (TMS) has arisen as a viable non-invasive treatment option with minimal side effects reported. TMS involves applying a magnetic field to a particular region of the brain in order to depolarize or hyperpolarize neurons at the target region. Generally, the target region is selected by a medical professional based on its relationship with the patient's condition. For example, the dorsolateral prefrontal cortex (DLPFC) is known to be involved with major depressive disorder. However, the exact location of the DLPFC in an individual can be difficult to manually identify. Even when it can be identified, there may in fact be a particular subregion of the DLPFC which would be the most effective target for the individual patient based on their idiosyncratic brain. Further, there may even be other regions in the brain that would provide better stimulation targets for the patient. As every brain is at least slightly different, a personalized way of generating stimulation targets for an individual can provide better treatment outcomes. An additional limitation of many TMS devices is the depth at which they can induce a current in a patient's brain. Often, TMS devices cannot target deep brain structures. However, there are numerous large-scale networks throughout the brain that have been identified. For example, the default mode network (DMN) is a network which appears to be involved with numerous tasks such as wakeful rest. By way of further example, the dorsal attention network (DAN) is thought to be key in voluntary orienting of visuospatial attention, and similarly the ventral attention network (VAN) reorients attention towards salient stimuli. Connectivity between different regions of the brain can provide an opportunity in TMS and other brain stimulation therapies whereby a more surface brain structure which is strongly connected to a deeper brain structure can be stimulated to effect change in the deeper brain region. Further, stimulation of connected networks can have significant impacts on structures within or otherwise connected to the network. Some networks in particular such as (but not limited to) the DMN, the DAN, and the VAN have particular experimentally determined relationships to major depressive disorder and suicidal ideation. Networks with relationships to a particular mental condition to be treated can be given additional priority. Given the complex nature of the brain, when applying a neuromodulation therapy (like TMS), the location at which the stimulation is delivered can have a significant impact on the outcome of the treatment. Targeting as discussed herein refers to the process of identifying target structures within a patient's brain for stimulation in order to treat mental health conditions. While current targeting methods can yield workable targets, many conventional methods have significant failings. For example, targeting often takes place using one scan from a patient and cannot incorporate multiple scans over time. Due to scanning noise and limited test-retest reliability of fMRI, deriving a target based on a single scan is more likely to be affected by noise and lead to a compromised levels of target reliability. Reliability limitation may be even more prominent for methods that employ voxel clustering for target detection, especially if clustering procedure is highly sensitive to noise and signal loss. Further, clustering procedures used for this purpose do not always consider the spatial relations between the voxels, which may lead to impractical results. Turning now to the drawings, systems and methods described herein seek to address these limitations, and provide a more robust targeting framework that produces more effective individualized stimulation targets for more effective treatment. In many embodiments, the targets produced using systems and methods described herein are subsequently used as the target in a neuromodulation therapy such as (but not limited to), TMS, transcranial direct current stimulation (tDCS), as the implantation location for one or more stimulation electrodes, and/or as the target for any number of different neuromodulation modalities as appropriate to the requirements of specific applications of embodiments of the invention. Targeting systems in accordance with embodiments of the invention are discussed below. Targeted Neuromodulation Systems Targeted neuromodulation systems are capable of obtaining and/or accessing scans of a patient's brain, and identifying one or more individualized targets for brain stimulation therapy. In many embodiments, targeting systems may be integrated into other medical devices, such as (but not limited to) TMS devices or neuronavigation devices. In various embodiments, targeting systems not only can generate individualized targets, but also include or be integrated with neuronavigation devices to identify where a TMS coil should be placed to correctly stimulate the target. In many embodiments, targeted neuromodulation systems can further apply neuromodulation to the generated target via a neuromodulation device such as (but not limited to) a TMS device, a tDCS device, an implantable neurostimulator, and/or any other neurostimulation device as appropriate to the requirements of specific applications of embodiments of the invention. Turning now toFIG.1, a targeted neuromodulation system in accordance with an embodiment of the invention is illustrated. Targeted neuromodulation system100includes a target generator110. Targeting generators can be implemented using any number of different computing platforms such as (but not limited to) desktop computers, laptops, server computers and/or clusters, smartphones, tablet PCs, and/or any other computing platform capable of executing logic instructions as appropriate to the requirements of specific applications of embodiments of the invention. In many embodiments, target generators determine personalized and/or partially-personalized targets within an individual's brain. Targeted neuromodulation system100further includes an fMRI machine120and a TMS device130. In many embodiments, the fMRI machine is capable of obtaining both structural and functional MRI images of a patient. The TMS device130can deliver brain stimulation therapy to the target selected by the target generator110. However, as can readily be appreciated, alternative imaging modalities (e.g. computed tomography, positron emission tomography, electroencephalography, etc.), and alternative brain stimulation devices can be used (e.g. implantable stimulators) as appropriate to the requirements of specific applications of embodiments of the invention; alternatively, the targeting system100may not include its own imaging equipment, and may receive imaging or other brain data from one or more imaging systems that are distinct from the neuromodulation system100. In many embodiments, the targeted neuromodulation system100includes a neuronavigation device which guides delivery of brain stimulation therapy by TMS device130to a target selected by the target generator110. This neuronavigation device may be integrated into the targeting generator110or separate (not shown) from the targeting system110. In numerous embodiments, neuronavigation devices assist in delivering brain stimulation therapy to one or more targets generated by a targeting system; for instance, by determining the rotational and translational position of a stimulating coil and head and displaying an image to guide a user to position the stimulating coil correctly, or by additionally using a mechanical actuator such as a robotic arm to position the stimulating coil correctly. As can be readily appreciated the specific function of a neuronavigation device can be varied depending on the type of neuromodulation being applied. In many embodiments, the fMRI, TMS device, targeting system, and/or neuronavigation device are connected via a network140. The network can be a wired network, a wireless network, or any combination thereof. Indeed, any number of different networks can be combined to connect the components. However, it is not a requirement that all components of the system be in communication via a network. Target generators are capable of performing without operative connections between other components. Indeed, as can be readily appreciated, while a specific targeted neuromodulation system is illustrated inFIG.1, any number of different system architectures can be used without departing from the scope or spirit of the invention. For example, in many embodiments, targeted neuromodulation systems can include different neuromodulation devices that provide different stimulation modalities. When targeting systems are provided with patient brain data, they are capable of generating individualized targets. Turning now toFIG.2, a target generator architecture in accordance with an embodiment of the invention is illustrated. Target generator200includes a processor210. However, in many embodiments, more than one processor can be used. In various embodiments, the processor can be made of any logic processing circuitry such as (but not limited to) central processing units (CPUs), graphics processing units (GPUs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), and/or any other circuit as appropriate to the requirements of specific applications of embodiments of the invention. The target generator200further includes an input/output (I/O) interface220. I/O interfaces are capable of transferring data between connected components such as (but not limited to) displays, TMS devices, fMRI machines, other treatment devices and/or imaging devices, and/or any other computer component as appropriate to the requirements of specific applications of embodiments of the invention. The target generator further includes a memory230. The memory can be implemented using volatile memory, non-volatile memory, or any combination thereof. As can be readily appreciated, any machine-readable storage media can be used as appropriate to the requirements of specific applications of embodiments of the invention. The memory230contains a targeting application232. The targeting application is capable of directing the processor to execute various target generation processes. The memory230is also capable of storing patient brain data234. Patient brain data describes brain scans of the patient such as, but not limited to, structural MRI and functional MRI scans. In numerous embodiments, the memory230can further contain normative connectivity data236describing expected generalized connectivity networks for a standard brain model. While particular target generator architectures and target generators are discussed in accordance with embodiments of the invention above, any number of different architectures and hardware designs can be used without departing from the scope or spirit of the invention. For example, in many embodiments, different stimulation modalities can be used. In various embodiments, transcranial direct current stimulation is used. In numerous embodiments, implantable electrical neurostimulators are used to directly stimulate brain tissue. Target generation processes for generating individualized stimulation targets are discussed in further detail below. Generating Individualized Stimulation Targets Some brain stimulation methods will work with some degree of efficacy without individualized, precision targeting. However, providing stimulation to a particular region of the brain to attempt to maximize the impact of treatment for an individual is highly beneficial. Various existing methodologies that attempt to generate personalized targets fail to fully consider the existing network connectivity in the brain and/or naïvely cluster regions within the brain. Target identification processes described herein can provide higher accuracy stimulation targets for an individual based on their personal brain network connectivity. Turning now toFIG.3, a flow chart of a target identification process for generating an individualized stimulation target for a patient in accordance with an embodiment of the invention is illustrated. Process300includes obtaining (310) patient brain data. As noted above, patient brain data can include structural and/or functional brain scans. In many embodiments, patient brain data includes both a structural MRI and a functional MRI scan. In various embodiments, multiple structural and/or functional MRI scans are included in the patient brain data which may have been captured at different times. MRI scans can be checked for quality. In various embodiments, scan quality is examined using commonly used fMRI quality control (QC) tools, and/or by matching whole brain connectivity structure against expected normative connectivity structure. Target identification processes for performing quality control using expected normative connectivity structure are discussed in further detail in a below section with reference toFIG.4. Process300further includes mapping (320) search and reference regions of interest (ROIs) onto the patient's brain. ROIs can be any brain structure, substructure, or group of structures of interest in the brain as decided by a user. Reference ROIs are ROIs that describe a region that the brain stimulation therapy should indirectly affect. In contrast, search ROIs describe regions in which individualized brain stimulation targets may reside. In this way, applying stimulation to an individualized brain stimulation target in a search ROI has an effect on the reference ROI. ROIs can be made up of one or more voxels depending on the size of the particular ROI. In some embodiments, ROIs may overlap. In numerous embodiments, a brain atlas is used to map ROIs onto a structural scan of the patient's brain. In various embodiments, target ROIs are indicated by applying a mask to the brain structure, where the mask flags desired target ROIs. In various embodiments, the mask can have different weight metrics for different desired target ROIs. ROIs can also be mapped onto functional scans. In various embodiments, a structural scan can be used as a template to align other functional scans. In various embodiments, multiple fMRI scans can be combined by integrating functional connectivity data to yield a “combined fMRI”. In this way, multiple fMRIs taken of a patient with similar or identical protocols can be merged to yield a more complete picture of an individual's network connectivity. fMRI signals (i.e. activity levels for a particular voxel or set of voxels over time) are extracted (330) from the ROIs. Voxels with poor signal quality can be excluded (335) and/or discarded. In numerous embodiments, poor quality signal can be caused due to various scanner limitations, scanning parameters and/or movement during the scanning process. In various embodiments, poor quality signals are detected by calculating voxel-level signal-to-noise ratio (SNR). By removing low quality signals from consideration, targeting accuracy can greatly increase. An individualized map of ROI parcellation is derived (340) from the extracted fMRI signals. The individualized map of ROI parcellations describes multiple parcels (or groups of adjacent voxels). Candidate parcels are derived from search ROIs, and constitute candidate targets for brain stimulation therapy. Reference parcels are derived from the reference ROI, and constitute areas of the reference ROI which will be impacted by the stimulation. Methods for deriving ROI parcellations in accordance with embodiments of the invention are discussed in further detail below with respect toFIG.5. Relationships between potential candidate and reference parcels are extracted (350) and a target score for potential candidate parcels are generated (360). In many embodiments, the functional connectivity between two parcels (a candidate and a reference) is measured and the target score is based on the strength of the functional connection. A target which has a stronger functional connectivity to a reference ROI (e.g. any parcel within the reference ROI), and therefore impacts functioning of the reference more strongly, can be given a higher target score. In many embodiments, other factors contribute to the score including (but not limited to) parcel depth, other functions of the parcel and/or surrounding brain structures, size, shape, and homogeneity of the parcel, fit to known/expected system/network-level connectivity profile, as well as numerous other factors can be considered as appropriate to the requirements of specific applications of embodiments of the invention. For example, a larger target may not have as strong functional connectivity to the reference, but is much larger and therefore easier to target with a specific brain stimulation device. By way of additional example, a network connectivity score can be included which incorporates network-level expectations regarding which brain region to target can be included. If, in the literature, the field believes that a particular brain structure or network (i.e. set of structures) is involved with a particular condition, parcels that interact strongly with that brain structure/network may be weighted more heavily as potential targets. As noted above, the DLPFC is believed to be strongly linked to clinical depression and suicidal ideation, and therefore targets that strongly interact with that region may be more desirable based on current expectations. As an example, in numerous embodiments, for each parcel, the difference between the functional connectivity to the DAN and the DMN can be calculated. Anticorrelation between the DAN and the DMN can be used as the network connectivity score, where a higher degree of anticorrelation suggests a stronger candidate parcel. In various embodiments, the difference between functional connectivity to the VAN and the DMN is calculated and used as a network connectivity score. In some embodiments, a weighted average of the network connectivity scores for different networks can be used as an overall network connectivity score, where the weights are based on the relevance of particular networks to a condition at issue. In various embodiments, the functional connectivities are calculated on a per-voxel basis and averaged to get an overall parcel score. An individualized target parcel is then selected (370) from the group of candidate parcels based on the target scores. In many embodiments, the highest scored candidate parcel is selected. In many embodiments, the center for the target parcel is extracted (380) in order to more precisely determine TMS coil alignment. In many embodiments, the center is calculated by averaging the position of each voxel making up the target candidate. While a particular method for generating an individualized target is illustrated inFIG.3, as can be readily appreciated, any number of different modifications can be made without departing from the scope or spirit of the invention. For example, not every quality control step needs to be taken or every parameter considered for generating a network score as appropriate to the requirements of specific applications of embodiments of the invention. Further, different weights may be given to different parameters as to their relative importance in calculating a target score. Additional description of various steps of the above processes are found below. Network Connectivity Quality Control Patient brain data can include one or more fMRI scans, however there is rarely an immediate guarantee that the data is high quality (e.g. having a high SNR). Measurement noise and head movement are known causes of fMRI reliability limitation and are thus estimated and partially addressed as common practice during data preprocessing. However, in some cases, poor scan quality and or preprocessing errors are missed which can lead to deriving a target based of faulty brain functional connectivity structure. To prevent making clinical decisions based on faulty data, additional means are desirable. Under the probable and acceptable assumption of overall preservation in system-level organization of the human brain, matching measured whole-brain connectivity against expected normative connectivity can reduce errors from bad scans and, in some cases, provide a flag to medical professionals the presence of atypical brains for further manual scrutiny. In many embodiments, identified bad scans are discarded. Turning now toFIG.4, a target identification process for measuring expected network connectivity in accordance with an embodiment of the invention is illustrated. Process400includes assigning (410) each voxel to a predefined network. Many large-scale brain networks are known and have been mapped based on large samples of the population such as (but not limited to) the visual network (VIS), the sensorimotor network (SMN), the dorsal attention network (DAN), the ventral attention network (VAN), the limbic network, the frontoparietal control network (FPCN), and the default mode network (DMN). These networks can be overlaid onto an MRI of a patient such that each voxel is assigned to at least one network. For each voxel pair, a functional connectivity score (FC) can be calculated (420), where the FC represents the strength of the connectivity between the voxels in an fMRI (including a combined fMRI). All of the FC values that link voxels that are assigned to the same network are averaged (430) to yield a “within FC” value. A “between FC” value is obtained by averaging (440) all FC values that link voxels from different networks. The between FC value is subtracted (450) from the within FC value to obtain a network fit for the voxel. While individual voxels may vary in their network association due to expected individual differences in brain function and structure, the average network fit across voxels (termed network quality control (QC) metric) is expected to remain positive (within FC>between FC) If the network QC metric is not significantly positive (mean between FC>=within FC), it is an indicator that there may be something either wrong with the scan, the preprocessing procedure or a significantly atypical structural issue occurring within the patient's brain. A statistical significance of network QC metric can be obtained by randomly permuting the data while considering voxel spatial positions and repeating the network QC estimation process. In this way, intake fMRIs can be cleared for quality. If an fMRI scan is flagged as having a poor overall network fit it can allow detailed inspection by a medical professional of the data and prevent deriving a target from faulty information. While a particular method for QC control based on brain network connectivity is illustrated in accordance with an embodiment of the invention inFIG.4, network connectivity can be used as a control using any of a number of different algorithms as appropriate to the requirements of specific applications of embodiments of the invention. Ensuring quality data can increase the accuracy of generated targets. A discussion of how to parcellate the brain into individualized ROIs is discussed further below. ROI Parcellation It is well known that while the overall structure of the human brain is relatively conserved across individuals, each person has idiosyncratic brain functionality and circuitry based on any number of factors both environmental and genetic. As such, merely dividing the brain based on a standardized model can yield inaccurate or insufficient results. While previous attempts have been made at parcellating the brain into ROIs, the particular methodologies used have often failed to robustly cluster voxels in an effective manner. Turning now toFIG.5, a target identification process for deriving an individualized map of ROI parcellation in accordance with an embodiment of the invention is discussed. Process500includes randomly subsampling (510) a percentage of all voxels. In many embodiments, the percentage is any number greater than 80%, however depending on the amount of data and compute available, this number can be less than 80%. The fMRI signals within the subsampled voxels are then clustered based on signal similarity (520). Any number of different clustering processes can be used including (but not limited to) agglomerative (hierarchical) clustering, Cluster Identification via Connectivity Kernels (CLICK) clustering, k-means clustering, and/or Spectral clustering. In some embodiments, clustering methods that incorporate spatial information (e.g. spatially constrained spectral clustering) can be used. The clustering assignment is recorded (530) and a new random subsampling (510) is obtained. The process can be repeated many times to increase accuracy. In many embodiments, this process is repeated 100 or more times to ensure enough data, although fewer can suffice. The subsample clustering solutions are then merged (540). In many embodiments, they are merged using a consensus clustering approach. Any resulting spatially disjoint clusters can then be split (550) into sub-clusters. The clusters (and any sub-clusters) are then labeled (560) as parcels, either reference or search based on their locations within reference and search ROIs. By repeatedly subsampling and clustering, noise in the neural signals can be accounted for and a more accurate picture of the individual's true brain connectivity can emerge. Furthermore, multiple fMRI scans can be run through this process and the resulting clusters can be integrated using consensus clustering. In this way, multiple fMRIs, including those taken on different days, can contribute to the overall dataset used for targeting. In various embodiments, spatially disjoint clusters can be avoided by using a spatially constrained clustering process. However, depending the requirements of specific applications of embodiments of the invention, it may be desirable to select a spatially unconstrained clustering process, which may yield spatially disjoint clusters. A target identification process for splitting spatially disjoint clusters in accordance with an embodiment of the invention is illustrated inFIG.6. Process600includes recording (610) the spatial position of each voxel in the spatially disjoint cluster. A distance matric indicating the physical distance between every two voxels is generated (620) which is then converted (630) into a graph representation. Long edges in the graph (edges that exceed a predefined threshold) are pruned (640) to yield a partially connected graph that is then split into connected sub-graphs (components) if such emerge. The set of voxels in each connected component can then be defined as a separate cluster (650). In this way, a disjoint cluster can be split and separately used as potential candidate parcels for stimulation. In many embodiments, these disjoint clusters are problematic the “center” of a disjoint cluster may be outside any part of the disjoint cluster and nowhere near a viable target location. Processes300,400,500, and/or600, and their variations, may be performed by a target identification system in order to provide a target parcel which then may be archived, stored for later use, transmitted to a neuronavigation device, used in further analysis, or combined with one or more other target parcels (for example, by union or intersection) to yield a composite target parcel. The target identification system may be distinct from, separate from, and/or integrated or partially integrated with a neuronavigation device. The target identification system may be implemented on a cloud computing platform, on a computing platform local to the site of treatment, on a computing platform incorporated into or part of a neuronavigation device, or any combination of such platforms. Although specific methods of ROI parcellation are discussed above, many different methods can be implemented in accordance with many different embodiments of the invention, such as (but not limited to) those that use different specific clustering processes, and/or utilize different thresholds and parameters. It is therefore to be understood that the present invention may be practiced in ways other than specifically described, without departing from the scope and spirit of the present invention. Thus, embodiments of the present invention should be considered in all respects as illustrative and not restrictive. Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their equivalents.

11857276

DETAILED DESCRIPTION The disclosure relates to systems and methods for internally guided navigation of catheters based on a model generated from CT image data. In the past, scanned two-dimensional (2D) images of the lungs have been used to aid in visualization. In order to obtain the 2D images, a patient undergoes a CT scans. In addition to using scanned 2D images, three-dimensional (3D) models may also be used to virtually navigate through the body. The use of 3D models for navigation is more complex than using 2D images and includes several challenges. One challenge involves guiding a catheter to the target in 3D. Many views have been developed, some of them using cross-sections, and a proposed view is designed to assist with guidance. However, when one tries to look through the whole volume from a point of view instead of looking at a cross-section, the view may be obstructed and objects, which are behind other objects, might not be seen. Methods have been developed to alleviate the obstructed view problem, such as adding transparency to some of the volume or highlighting farther objects. One of the known methods involves Maximum Intensity Projection (MIP) which is a volume rendering method for 3D data that projects in the visualization plane the voxels with maximum intensity that fall in the way of parallel rays traced from the viewpoint to the plane of projection. However, when using MIP to align an electromagnetic navigation catheter towards a lesion, traditional methods may result in lesions located beyond objects, such as bones or other non-soft tissue, not being visible. Therefore, there is a need to develop new view development techniques that improve upon MIP. The disclosure is related to devices, systems, and methods for internally guided navigation of catheters based on a model generated from CT image data to guide a catheter to a target. In the disclosure, the system provides a view of a defined section of a volume from the perspective of the catheter. To achieve the view disclosed in the current application, two filters are separately applied to a rendered 3D volume. The filters isolate airway tissue and lesion tissue from the 3D rendering so that it can be combined in order to generate a view which presents only airways and lesions and eliminates obstacles such as bones which would ordinarily obscure a view from the catheter. Alignment of catheter102may be a necessary component of pathway planning for performing an ELECTROMAGNETIC NAVIGATION BRONCHOSCOPY® (ENB) procedure using an electromagnetic navigation (EMN) system. An ENB procedure generally involves at least two phases: (1) planning a pathway to a target located within, or adjacent to, the patient's lungs; and (2) navigating a probe to the target along the planned pathway. These phases are generally referred to as (1) “planning” and (2) “navigation.” The planning phase of an ENB procedure is more fully described in commonly-owned U.S. Pat. Nos. 9,459,770; and 9,639,666 and U.S. Patent Publication No. 2014/0270441, all entitled “Pathway Planning System and Method,” filed on Mar. 15, 2013, by Baker, the entire contents of which are hereby incorporated by reference. An example of the navigation software can be found in commonly assigned U.S. Patent Publication No. 2016/0000302 entitled “SYSTEM AND METHOD FOR NAVIGATING WITHIN THE LUNG” the entire contents of which are incorporated herein by reference. Prior to the planning phase, the patient's lungs are imaged by, for example, a computed tomography (CT) scan, although additional applicable methods of imaging will be known to those skilled in the art. The image data assembled during the CT scan may then be stored in, for example, the Digital Imaging and Communications in Medicine (DICOM) format, although additional applicable formats will be known to those skilled in the art. The CT scan image data may then be loaded into a planning software application (“application”) to be used during the planning phase of the ENB procedure. Embodiments of the systems and methods are described with reference to the accompanying drawings. Like reference numerals may refer to similar or identical elements throughout the description of the figures. This description may use the phrases “in an embodiment,” “in embodiments,” “in some embodiments,” or “in other embodiments,” which may each refer to one or more of the same or different embodiments in accordance with the disclosure. FIG.1illustrates an electromagnetic navigation (EMN) system10in accordance with the disclosure. Among other tasks that may be performed using the EMN system10are planning a pathway to target tissue, navigating a positioning assembly to the target tissue, navigating a catheter102to the target tissue to obtain a tissue sample from the target tissue using catheter102, and digitally marking the location where the tissue sample was obtained, and placing one or more echogenic markers at or around the target. EMN system10generally includes an operating table40configured to support a patient; a bronchoscope50configured for insertion through the patient's mouth and/or nose into the patient's airways; monitoring equipment60coupled to bronchoscope50for displaying video images received from bronchoscope50; a tracking system70including a tracking module72, a plurality of reference sensors74, and an electromagnetic field generator76; a workstation80including software and/or hardware used to facilitate pathway planning, identification of target tissue, navigation to target tissue, and digitally marking the biopsy location FIG.1also depicts two types of catheter guide assemblies90,100. Both catheter guide assemblies90,100are usable with the EMN system10and share a number of common components. Each catheter guide assembly90,100includes a handle91, which is connected to an extended working channel (EWC)96. The EWC96is sized for placement into the working channel of a bronchoscope50. In operation, a locatable guide (LG)92, including an electromagnetic (EM) sensor94, is inserted into the EWC96and locked into position such that the sensor94extends a desired distance beyond the distal tip93of the EWC96. The location of the EM sensor94, and thus the distal end of the EWC96, within an electromagnetic field generated by the electromagnetic field generator76can be derived by the tracking module72, and workstation80. FIG.2illustrates a system diagram of workstation80. Workstation80may include memory202, processor204, display206, network interface208, input device210, and/or output module212. Workstation80implements the methods that will be described herein. FIG.3depicts a method of navigation using the navigation workstation80and the user interface216. At step S300user interface216presents the clinician with a view (not shown) for the selection of a patient. The clinician may enter patient information such as, for example, the patient name or patient ID number, into a text box to select a patient on which to perform a navigation procedure. Alternatively, the patient may be selected from a drop down menu or other similar methods of patient selection. Once the patient has been selected, the user interface216presents the clinician with a view (not shown) including a list of available navigation plans for the selected patient. At step S302, the clinician may load one of the navigation plans by activating the navigation plan. The navigation plans may be imported from a procedure planning software and include CT images of the selected patient. Once the patient has been selected and a corresponding navigation plan has been loaded, the user interface216presents the clinician with a patient details view (not shown) At step S304which allows the clinician to review the selected patient and plan details. Examples of patient details presented to the clinician in the timeout view may include the patient's name, patient ID number, and birth date. Examples of plan details include navigation plan details, automatic registration status, and/or manual registration status. For example, the clinician may activate the navigation plan details to review the navigation plan, and may verify the availability of automatic registration and/or manual registration. The clinician may also activate an edit button edit the loaded navigation plan from the patient details view. Activating the edit button of the loaded navigation plan may also activate the planning software described above. Once the clinician is satisfied that the patient and plan details are correct, the clinician proceeds to navigation setup at step S306. Alternatively, medical staff may perform the navigation setup prior to or concurrently with the clinician selecting the patient and navigation plan. During navigation setup at step S306, the clinician or other medical staff prepares the patient and operating table by positioning the patient on the operating table over the electromagnetic field generator76. The clinician or other medical staff position reference sensors74on the patient's chest and verify that the sensors are properly positioned, for example, through the use of a setup view presented to the clinician or other medical staff by user interface216. Setup view may, for example, provide the clinician or other medical staff with an indication of where the reference sensors74are located relative to the magnetic field generated by the electromagnetic field generator76. Patient sensors allow the navigation system to compensate for patient breathing cycles during navigation. The clinician also prepares LG92, EWC96, and bronchoscope50for the procedure by inserting LG92into EWC96and inserting both LG92and EWC96into the working channel of bronchoscope50such that distal tip93of LG92extends from the distal end of the working channel of bronchoscope50. For example, the clinician may extend the distal tip93of LG9210 mm beyond the distal end of the working channel of bronchoscope50. Once setup is complete, workstation80presents a view400, as shown inFIG.4, via the user interface216. CT image data is acquired and displayed at step308. At step310, the CT image data is registered with the selected navigation plan. An example method for registering images with a navigation plan is described in the aforementioned U.S. Patent Publication No. 2016/0000302. At step S312, workstation80performs a volume rendering algorithm based on the CT image data included in the navigation plan and position signals from sensor94to generate a 3D view404of the walls of the patient's airways as shown inFIG.4. The 3D view404uses a perspective rendering that supports perception of advancement when moving closer to objects in the volume. The 3D view404also presents the user with a navigation pathway providing an indication of the direction along which the user will need to travel to reach the lesion410. The navigation pathway may be presented in a color or shape that contrasts with the 3D rendering so that the user may easily determine the desired path to travel. Workstation80also presents a local view406as shown inFIG.4that includes a slice of the 3D volume located at and aligned with the distal tip93of LG92. Local view406shows the lesion410and the navigation pathway414overlaid on slice416from an elevated perspective. The slice416that is presented by local view406changes based on the location of EM sensor94relative to the 3D volume of the loaded navigation plan. Local view406also presents the user with a virtual representation of the distal tip93of LG92in the form of a virtual probe418. The virtual probe418provides the user with an indication of the direction that distal tip93of LG92is facing so that the user can control the advancement of the LG92in the patient's airways. At step S314, catheter102is navigated through the airways. Catheter102may be navigated through catheter guide assemblies90,100until catheter102approaches the target. Alternatively, catheter102may be navigated independently of catheter guide assemblies90,100. Catheter102is navigated via manipulation of handle91which can be manipulated by rotation and compression. Once catheter102is located approximate the target, steps S314-S316begin in order to render a 3D volume including locations of one or more airways and one or more targets. Until catheter102is located at the target, catheter102is further navigated, at step S314, using the 3D volume and locations of one or more airways and one or more targets continually generated in steps S314-S316. At steps S316and S320, a view including lungs and lesions is rendered by projecting, from the location and orientation (i.e., the perspective) of catheter102, parallel beams which accumulate densities until they encounter an opaque object (e.g., bone). The volume rendering is performed in two steps: 1) collecting voxel data and 2) accumulating the voxel data in the direction of the beams, which is projected from the location and orientation of catheter102, until the beam is stopped, at which point the voxel data is added together. Further at step S316, workstation80applies a first transfer function to the volume rendered at step S314. The first transfer function is applied to a limited range projected from the position of catheter102. The limited range may be predefined or be dynamically calculated based on a location of and/or distance to the target. Along the limited range projected from the position of catheter102, the first transfer function accumulates voxels which have a density and/or a color within a certain range indicating that the pixel represents a wall of a patient's airways. As a result of applying the first transfer function, workstation80generates a filtered volume rendering preferably showing the patient's airways. Further at step S318, workstation80assesses the result of applying the first transfer function to the rendered volume. Workstation80may use, for example, image recognition software to determine whether recognizable, airway-shaped elements are visible in the filtered volume rendering. Alternatively, the filtered volume rendering may be presented to the clinician such that the clinician may inspect the filtered volume rendering and determine whether airways are visible. The clinician may then indicate on the user interface whether airways are visible. If either workstation80or the clinician determines that airways are not visible, the process returns to step S316wherein the first transfer function is re-applied to the volume rendering with a modified filtering threshold, a modified accumulation of voxels, or a modified projection range. If, at step S316, either workstation80or the clinician determines that a requisite number of airways are visible, the process proceeds to step S320. At step S320, workstation80applies a second transfer function to the volume rendered at step S314. The second transfer function is applied to an unlimited range projected from the position of catheter102. Though, as a practical matter, it is likely that the projected range will be limited by the size of the rendered volume. The second transfer function may also be applied to a limited range projected from the position of catheter102. Along the range projected from the position of catheter102, the second transfer function accumulates voxels which have a density and/or a color within a certain range indicating that the pixel represents a target tissue such as a lesion. Applying the second transfer function to an unlimited range from the position of catheter102allows voxels representing target tissue such as a lesion to be detected and shown beyond opaque objects (e.g., bones). As a result of applying the second transfer function to the rendered volume, workstation80generates a filtered volume rendering preferably showing target tissues, including those located beyond bones and other opaque objects. At steps S322, workstation80assesses the result of applying the second transfer function to the rendered volume. Workstation80may use, for example, image recognition software to determine whether recognizable, airway-shaped elements are visible in the filtered volume rendering. Alternatively, the filtered volume rendering may be presented to the clinician such that the clinician may inspect the filtered volume rendering and determine whether airways are visible. The clinician may then indicate on the user interface whether target tissue is visible. If either workstation80or the clinician determines that target tissue is not visible, the process returns to step S320wherein the second transfer function is re-applied to the volume rendering with a modified filtering threshold, a modified accumulation of voxels, or a modified projection range. If, at step S322, either workstation80or the clinician determines that a target tissue is visible, the process proceeds to step S324. Limiting the transfer functions to highlighted structures within the limited range of the distal tip93may reduce the load on processor204. By using a limited range, denser structures that may obscure the lesion may be omitted permitting the lesion to be displayed. The second transfer function may be configured to cause lesions within the range to be displayed in their maximal surface size permitting the user to aim for the center of the target. As shown in alignment view402, the second transfer functions may be tuned to highlight lesion-density tissue and filter out most other densities in the CT volume, creating a clearer picture in which lung lesions stand out over dark background. A marking408, e.g., a sphere or ellipsoid, may be used to represent the planned target and is overlaid on the rendered volume to reduce risk of aligning to the wrong object. A crosshair415in the center of the view assists the user in aligning distal tip93with the center of the target. The distance412from the distal tip93to the center of the marked target is displayed next to the crosshair415, permitting the user to find the best balance between alignment and proximity At step S324, the filtered volume rendering generated by applying the first transfer function and the filtered volume rendering generated by applying the second transfer function are combined in order to generate a display showing the patient's airways and target tissue. An example displays resulting from the combination are shown atFIG.4. At step S326, the clinician or workstation80determines whether the catheter is a located at the target. If the catheter is not located at the target, the process returns to step S314wherein the clinician continues to navigate the catheter toward the target. As the catheter is navigated toward the target, the display volume is continually rendering and the first and the second transfer functions are applied to generate a view showing airways and the target. In the embodiments, the alignment of catheter102using CT image data and 3D models permits a better aiming experience over other CT volume representations. Target areas of lesions may be shown from a distance, where a normal CT slice would not be useful. The embodiments permit a user to assess optimal balance between alignment/proximity, which defines the best location for catheter introduction. The view looks similar to CT images thereby assuring clinicians that the information they are looking at is real, permits aiming to various parts of the lesion structure, and assures users that they are at the planned target. In the 3D models, irrelevant structures in the range are reduced or eliminated, permitting the user to clearly identify the target. FIG.4shows 3D view404which show walls of the patient's airways. The 3D view404uses a perspective rendering that supports perception of advancement when moving closer to objects in the volume. The 3D view404also presents the user with a navigation pathway providing an indication of the direction along which the user will need to travel to reach the lesion410. The navigation pathway may be presented in a color or shape that contrasts with the 3D rendering so that the user may easily determine the desired path to travel. Workstation80also presents a local view406as shown inFIG.4that includes a slice of the 3D volume located at and aligned with the distal tip93of LG92. Local view406shows the lesion410and the navigation pathway414overlaid on slice416from an elevated perspective. The slice416that is presented by local view406changes based on the location of EM sensor94relative to the 3D volume of the loaded navigation plan. Local view406also presents the user with a virtual representation of the distal tip93of LG92in the form of a virtual probe418. The virtual probe418provides the user with an indication of the direction that distal tip93of LG92is facing so that the user can control the advancement of the LG92in the patient's airways. Referring back toFIG.1, catheter guide assemblies90,100have different operating mechanisms, but each contain a handle91that can be manipulated by rotation and compression to steer the distal tip93of the LG92, extended working channel96. Catheter guide assemblies90are currently marketed and sold by Covidien LP under the name SUPERDIMENSION® Procedure Kits, similarly catheter guide assemblies100are currently sold by Covidien LP under the name EDGE™ Procedure Kits, both kits include a handle91, extended working channel96, and locatable guide92. For a more detailed description of the catheter guide assemblies90,100reference is made to commonly-owned U.S. patent application Ser. No. 13/836,203 filed on Mar. 15, 2013 by Ladtkow et al., the entire contents of which are hereby incorporated by reference. InFIG.1, the patient is shown lying on operating table40with bronchoscope50inserted through the patient's mouth and into the patient's airways. Bronchoscope50includes a source of illumination and a video imaging system (not explicitly shown) and is coupled to monitoring equipment60, e.g., a video display, for displaying the video images received from the video imaging system of bronchoscope50. Catheter guide assemblies90,100including LG92and EWC96are configured for insertion through a working channel of bronchoscope50into the patient's airways (although the catheter guide assemblies90,100may alternatively be used without bronchoscope50). The LG92and EWC96are selectively lockable relative to one another via a locking mechanism99. A six degrees-of-freedom electromagnetic tracking system70, e.g., similar to those disclosed in U.S. Pat. No. 6,188,355 and published PCT Application Nos. WO 00/10456 and WO 01/67035, the entire contents of each of which is incorporated herein by reference, or any other suitable positioning measuring system, is utilized for performing navigation, although other configurations are also contemplated. Tracking system70is configured for use with catheter guide assemblies90,100to track the position of the EM sensor94as it moves in conjunction with the EWC96through the airways of the patient, as detailed below. As shown inFIG.1, electromagnetic field generator76is positioned beneath the patient. Electromagnetic field generator76and the plurality of reference sensors74are interconnected with tracking module72, which derives the location of each reference sensor74in six degrees of freedom. One or more of reference sensors74are attached to the chest of the patient. The six degrees of freedom coordinates of reference sensors74are sent to workstation80, which includes application81where sensors74are used to calculate a patient coordinate frame of reference. Also shown inFIG.1is catheter102which is insertable into the catheter guide assemblies90,100following navigation to a target and removal of the LG92. The catheter102is used to collect one or more tissue samples from the target tissue. As detailed below, catheter102is further configured for use in conjunction with tracking system70to facilitate navigation of catheter102to the target tissue, tracking of a location of catheter102as it is manipulated relative to the target tissue to obtain the tissue sample, and/or marking the location where the tissue sample was obtained. Although navigation is detailed above with respect to EM sensor94being included in the LG92it is also envisioned that EM sensor94may be embedded or incorporated within catheter102where catheter102may alternatively be utilized for navigation without need of the LG or the necessary tool exchanges that use of the LG requires. A variety of useable catheters are described in U.S. Patent Publication Nos. 2015/0141869 and 2015/0141809 both entitled DEVICES, SYSTEMS, AND METHODS FOR NAVIGATING A CATHETER TO A TARGET LOCATION AND OBTAINING A TISSUE SAMPLE USING THE SAME, filed Nov. 20, 2013 and U.S. Patent Publication No. 2015/0265257 having the same title and filed Mar. 14, 2014, the entire contents of each of which are incorporated herein by reference and useable with the EMN system10as described herein. During procedure planning, workstation80utilizes computed tomographic (CT) image data for generating and viewing a three-dimensional model (“3D model”) of the patient's airways, enables the identification of target tissue on the 3D model (automatically, semi-automatically or manually), and allows for the selection of a pathway through the patient's airways to the target tissue. More specifically, the CT scans are processed and assembled into a 3D volume, which is then utilized to generate the 3D model of the patient's airways. The 3D model may be presented on a display monitor81associated with workstation80, or in any other suitable fashion. Using workstation80, various slices of the 3D volume and views of the 3D model may be presented and/or may be manipulated by a clinician to facilitate identification of a target and selection of a suitable pathway through the patient's airways to access the target. The 3D model may also show marks of the locations where previous biopsies were performed, including the dates, times, and other identifying information regarding the tissue samples obtained. These marks may also be selected as the target to which a pathway can be planned. Once selected, the pathway is saved for use during the navigation procedure. An example of a suitable pathway planning system and method is described in the aforementioned U.S. Pat. Nos. 9,459,770; and 9,639,666 and U.S. Patent Publication No. 2014/0270441. During navigation, EM sensor94, in conjunction with tracking system70, enables tracking of EM sensor94and/or catheter102as EM sensor94or catheter102is advanced through the patient's airways. Referring back toFIG.2, memory202includes any non-transitory computer-readable storage media for storing data and/or software that is executable by processor204and which controls the operation of workstation80. In an embodiment, memory202may include one or more solid-state storage devices such as flash memory chips. Alternatively or in addition to the one or more solid-state storage devices, memory202may include one or more mass storage devices connected to the processor204through a mass storage controller (not shown) and a communications bus (not shown). Although the description of computer-readable media contained herein refers to a solid-state storage, it should be appreciated by those skilled in the art that computer-readable storage media can be any available media that can be accessed by the processor204. That is, computer readable storage media includes non-transitory, volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules or other data. For example, computer-readable storage media includes RAM, ROM, EPROM, EEPROM, flash memory or other solid state memory technology, CD-ROM, DVD, Blu-Ray or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by workstation80. Memory202may store application81and/or CT data214. Application81may, when executed by processor204, cause display206to present user interface216. Network interface208may be configured to connect to a network such as a local area network (LAN) consisting of a wired network and/or a wireless network, a wide area network (WAN), a wireless mobile network, a Bluetooth network, and/or the internet. Input device210may be any device by means of which a user may interact with workstation80, such as, for example, a mouse, keyboard, foot pedal, touch screen, and/or voice interface. Output module212may include any connectivity port or bus, such as, for example, parallel ports, serial ports, universal serial busses (USB), or any other similar connectivity port known to those skilled in the art. Any of the described methods, programs, algorithms or codes may be converted to, or expressed in, a programming language or computer program. A “Programming Language” and “Computer Program” is any language used to specify instructions to a computer, and includes (but is not limited to) these languages and their derivatives: Assembler, Basic, Batch files, BCPL, C, C+, C++, Delphi, Fortran, Java, JavaScript, Machine code, operating system command languages, Pascal, Perl, PL1, scripting languages, Visual Basic, metalanguages which themselves specify programs, and all first, second, third, fourth, and fifth generation computer languages. Also included are database and other data schemas, and any other meta-languages. For the purposes of this definition, no distinction is made between languages which are interpreted, compiled, or use both compiled and interpreted approaches. For the purposes of this definition, no distinction is made between compiled and source versions of a program. Thus, reference to a program, where the programming language could exist in more than one state (such as source, compiled, object, or linked) is a reference to any and all such states. The definition also encompasses the actual instructions and the intent of those instructions. Although embodiments have been described in detail with reference to the accompanying drawings for the purpose of illustration and description, it is to be understood that the inventive processes and apparatus are not to be construed as limited thereby. It will be apparent to those of ordinary skill in the art that various modifications to the foregoing embodiments may be made without departing from the scope of the disclosure.

11857277

DETAILED DESCRIPTION 1. Overview. Aspects of the present disclosure may be integrated into a robotically-enabled medical system capable of performing a variety of medical procedures, including both minimally invasive, such as laparoscopy, and non-invasive, such as endoscopy, procedures. Among endoscopy procedures, the system may be capable of performing bronchoscopy, ureteroscopy, gastroscopy, etc. In addition to performing the breadth of procedures, the system may provide additional benefits, such as enhanced imaging and guidance to assist the physician. Additionally, the system may provide the physician with the ability to perform the procedure from an ergonomic position without the need for awkward arm motions and positions. Still further, the system may provide the physician with the ability to perform the procedure with improved ease of use such that one or more of the instruments of the system can be controlled by a single user. Various embodiments will be described below in conjunction with the drawings for purposes of illustration. It should be appreciated that many other implementations of the disclosed concepts are possible, and various advantages can be achieved with the disclosed implementations. Headings are included herein for reference and to aid in locating various sections. These headings are not intended to limit the scope of the concepts described with respect thereto. Such concepts may have applicability throughout the entire specification. A. Robotic System—Cart. The robotically-enabled medical system may be configured in a variety of ways depending on the particular procedure.FIG.1illustrates an embodiment of a cart-based robotically-enabled system10arranged for a diagnostic and/or therapeutic bronchoscopy procedure. During a bronchoscopy, the system10may comprise a cart11having one or more robotic arms12to deliver a medical instrument, such as a steerable endoscope13, which may be a procedure-specific bronchoscope for bronchoscopy, to a natural orifice access point (i.e., the mouth of the patient positioned on a table in the present example) to deliver diagnostic and/or therapeutic tools. As shown, the cart11may be positioned proximate to the patient's upper torso in order to provide access to the access point. Similarly, the robotic arms12may be actuated to position the bronchoscope relative to the access point. The arrangement inFIG.1may also be utilized when performing a gastro-intestinal (GI) procedure with a gastroscope, a specialized endoscope for GI procedures.FIG.2depicts an example embodiment of the cart in greater detail. With continued reference toFIG.1, once the cart11is properly positioned, the robotic arms12may insert the steerable endoscope13into the patient robotically, manually, or a combination thereof. As shown, the steerable endoscope13may comprise at least two telescoping parts, such as an inner leader portion and an outer sheath portion, each portion coupled to a separate instrument driver from the set of instrument drivers28, each instrument driver coupled to the distal end of an individual robotic arm. This linear arrangement of the instrument drivers28, which facilitates coaxially aligning the leader portion with the sheath portion, creates a “virtual rail”29that may be repositioned in space by manipulating the one or more robotic arms12into different angles and/or positions. The virtual rails described herein are depicted in the Figures using dashed lines, and accordingly the dashed lines do not depict any physical structure of the system. Translation of the instrument drivers28along the virtual rail29telescopes the inner leader portion relative to the outer sheath portion or advances or retracts the endoscope13from the patient. The angle of the virtual rail29may be adjusted, translated, and pivoted based on clinical application or physician preference. For example, in bronchoscopy, the angle and position of the virtual rail29as shown represents a compromise between providing physician access to the endoscope13while minimizing friction that results from bending the endoscope13into the patient's mouth. The endoscope13may be directed down the patient's trachea and lungs after insertion using precise commands from the robotic system until reaching the target destination or operative site. In order to enhance navigation through the patient's lung network and/or reach the desired target, the endoscope13may be manipulated to telescopically extend the inner leader portion from the outer sheath portion to obtain enhanced articulation and greater bend radius. The use of separate instrument drivers28also allows the leader portion and sheath portion to be driven independent of each other. For example, the endoscope13may be directed to deliver a biopsy needle to a target, such as, for example, a lesion or nodule within the lungs of a patient. The needle may be deployed down a working channel that runs the length of the endoscope to obtain a tissue sample to be analyzed by a pathologist. Depending on the pathology results, additional tools may be deployed down the working channel of the endoscope for additional biopsies. After identifying a nodule to be malignant, the endoscope13may endoscopically deliver tools to resect the potentially cancerous tissue. In some instances, diagnostic and therapeutic treatments can be delivered in separate procedures. In those circumstances, the endoscope13may also be used to deliver a fiducial to “mark” the location of the target nodule as well. In other instances, diagnostic and therapeutic treatments may be delivered during the same procedure. The system10may also include a movable tower30, which may be connected via support cables to the cart11to provide support for controls, electronics, fluidics, optics, sensors, and/or power to the cart11. Placing such functionality in the tower30allows for a smaller form factor cart11that may be more easily adjusted and/or re-positioned by an operating physician and his/her staff. Additionally, the division of functionality between the cart/table and the support tower30reduces operating room clutter and facilitates improving clinical workflow. While the cart11may be positioned close to the patient, the tower30may be stowed in a remote location to stay out of the way during a procedure. In support of the robotic systems described above, the tower30may include component(s) of a computer-based control system that stores computer program instructions, for example, within a non-transitory computer-readable storage medium such as a persistent magnetic storage drive, solid state drive, etc. The execution of those instructions, whether the execution occurs in the tower30or the cart11, may control the entire system or sub-system(s) thereof. For example, when executed by a processor of the computer system, the instructions may cause the components of the robotics system to actuate the relevant carriages and arm mounts, actuate the robotics arms, and control the medical instruments. For example, in response to receiving the control signal, the motors in the joints of the robotics arms may position the arms into a certain posture. The tower30may also include a pump, flow meter, valve control, and/or fluid access in order to provide controlled irrigation and aspiration capabilities to the system that may be deployed through the endoscope13. These components may also be controlled using the computer system of tower30. In some embodiments, irrigation and aspiration capabilities may be delivered directly to the endoscope13through separate cable(s). The tower30may include a voltage and surge protector designed to provide filtered and protected electrical power to the cart11, thereby avoiding placement of a power transformer and other auxiliary power components in the cart11, resulting in a smaller, more moveable cart11. The tower30may also include support equipment for the sensors deployed throughout the robotic system10. For example, the tower30may include opto-electronics equipment for detecting, receiving, and processing data received from the optical sensors or cameras throughout the robotic system10. In combination with the control system, such opto-electronics equipment may be used to generate real-time images for display in any number of consoles deployed throughout the system, including in the tower30. Similarly, the tower30may also include an electronic subsystem for receiving and processing signals received from deployed electromagnetic (EM) sensors. The tower30may also be used to house and position an EM field generator for detection by EM sensors in or on the medical instrument. The tower30may also include a console31in addition to other consoles available in the rest of the system, e.g., console mounted on top of the cart. The console31may include a user interface and a display screen, such as a touchscreen, for the physician operator. Consoles in system10are generally designed to provide both robotic controls as well as pre-operative and real-time information of the procedure, such as navigational and localization information of the endoscope13. When the console31is not the only console available to the physician, it may be used by a second operator, such as a nurse, to monitor the health or vitals of the patient and the operation of system, as well as provide procedure-specific data, such as navigational and localization information. In other embodiments, the console30is housed in a body that is separate from the tower30. The tower30may be coupled to the cart11and endoscope13through one or more cables or connections (not shown). In some embodiments, the support functionality from the tower30may be provided through a single cable to the cart11, simplifying and de-cluttering the operating room. In other embodiments, specific functionality may be coupled in separate cabling and connections. For example, while power may be provided through a single power cable to the cart, the support for controls, optics, fluidics, and/or navigation may be provided through a separate cable. FIG.2provides a detailed illustration of an embodiment of the cart from the cart-based robotically-enabled system shown inFIG.1. The cart11generally includes an elongated support structure14(often referred to as a “column”), a cart base15, and a console16at the top of the column14. The column14may include one or more carriages, such as a carriage17(alternatively “arm support”) for supporting the deployment of one or more robotic arms12(three shown inFIG.2). The carriage17may include individually configurable arm mounts that rotate along a perpendicular axis to adjust the base of the robotic arms12for better positioning relative to the patient. The carriage17also includes a carriage interface19that allows the carriage17to vertically translate along the column14. The carriage interface19is connected to the column14through slots, such as slot20, that are positioned on opposite sides of the column14to guide the vertical translation of the carriage17. The slot20contains a vertical translation interface to position and hold the carriage at various vertical heights relative to the cart base15. Vertical translation of the carriage17allows the cart11to adjust the reach of the robotic arms12to meet a variety of table heights, patient sizes, and physician preferences. Similarly, the individually configurable arm mounts on the carriage17allow the robotic arm base21of robotic arms12to be angled in a variety of configurations. In some embodiments, the slot20may be supplemented with slot covers that are flush and parallel to the slot surface to prevent dirt and fluid ingress into the internal chambers of the column14and the vertical translation interface as the carriage17vertically translates. The slot covers may be deployed through pairs of spring spools positioned near the vertical top and bottom of the slot20. The covers are coiled within the spools until deployed to extend and retract from their coiled state as the carriage17vertically translates up and down. The spring-loading of the spools provides force to retract the cover into a spool when carriage17translates towards the spool, while also maintaining a tight seal when the carriage17translates away from the spool. The covers may be connected to the carriage17using, for example, brackets in the carriage interface19to ensure proper extension and retraction of the cover as the carriage17translates. The column14may internally comprise mechanisms, such as gears and motors, that are designed to use a vertically aligned lead screw to translate the carriage17in a mechanized fashion in response to control signals generated in response to user inputs, e.g., inputs from the console16. The robotic arms12may generally comprise robotic arm bases21and end effectors22, separated by a series of linkages23that are connected by a series of joints24, each joint comprising an independent actuator, each actuator comprising an independently controllable motor. Each independently controllable joint represents an independent degree of freedom available to the robotic arm. Each of the arms12have seven joints, and thus provide seven degrees of freedom. A multitude of joints result in a multitude of degrees of freedom, allowing for “redundant” degrees of freedom. Redundant degrees of freedom allow the robotic arms12to position their respective end effectors22at a specific position, orientation, and trajectory in space using different linkage positions and joint angles. This allows for the system to position and direct a medical instrument from a desired point in space while allowing the physician to move the arm joints into a clinically advantageous position away from the patient to create greater access, while avoiding arm collisions. The cart base15balances the weight of the column14, carriage17, and arms12over the floor. Accordingly, the cart base15houses heavier components, such as electronics, motors, power supply, as well as components that either enable movement and/or immobilize the cart. For example, the cart base15includes rollable wheel-shaped casters25that allow for the cart to easily move around the room prior to a procedure. After reaching the appropriate position, the casters25may be immobilized using wheel locks to hold the cart11in place during the procedure. Positioned at the vertical end of column14, the console16allows for both a user interface for receiving user input and a display screen (or a dual-purpose device such as, for example, a touchscreen26) to provide the physician user with both pre-operative and intra-operative data. Potential pre-operative data on the touchscreen26may include pre-operative plans, navigation and mapping data derived from pre-operative computerized tomography (CT) scans, and/or notes from pre-operative patient interviews. Intra-operative data on display may include optical information provided from the tool, sensor and coordinate information from sensors, as well as vital patient statistics, such as respiration, heart rate, and/or pulse. The console16may be positioned and tilted to allow a physician to access the console from the side of the column14opposite carriage17. From this position, the physician may view the console16, robotic arms12, and patient while operating the console16from behind the cart11. As shown, the console16also includes a handle27to assist with maneuvering and stabilizing cart11. FIG.3illustrates an embodiment of a robotically-enabled system10arranged for ureteroscopy. In a ureteroscopic procedure, the cart11may be positioned to deliver a ureteroscope32, a procedure-specific endoscope designed to traverse a patient's urethra and ureter, to the lower abdominal area of the patient. In a ureteroscopy, it may be desirable for the ureteroscope32to be directly aligned with the patient's urethra to reduce friction and forces on the sensitive anatomy in the area. As shown, the cart11may be aligned at the foot of the table to allow the robotic arms12to position the ureteroscope32for direct linear access to the patient's urethra. From the foot of the table, the robotic arms12may insert the ureteroscope32along the virtual rail33directly into the patient's lower abdomen through the urethra. After insertion into the urethra, using similar control techniques as in bronchoscopy, the ureteroscope32may be navigated into the bladder, ureters, and/or kidneys for diagnostic and/or therapeutic applications. For example, the ureteroscope32may be directed into the ureter and kidneys to break up kidney stone build up using a laser or ultrasonic lithotripsy device deployed down the working channel of the ureteroscope32. After lithotripsy is complete, the resulting stone fragments may be removed using baskets deployed down the ureteroscope32. FIG.4illustrates an embodiment of a robotically-enabled system similarly arranged for a vascular procedure. In a vascular procedure, the system10may be configured such that the cart11may deliver a medical instrument34, such as a steerable catheter, to an access point in the femoral artery in the patient's leg. The femoral artery presents both a larger diameter for navigation as well as a relatively less circuitous and tortuous path to the patient's heart, which simplifies navigation. As in a ureteroscopic procedure, the cart11may be positioned towards the patient's legs and lower abdomen to allow the robotic arms12to provide a virtual rail35with direct linear access to the femoral artery access point in the patient's thigh/hip region. After insertion into the artery, the medical instrument34may be directed and inserted by translating the instrument drivers28. Alternatively, the cart may be positioned around the patient's upper abdomen in order to reach alternative vascular access points, such as, for example, the carotid and brachial arteries near the shoulder and wrist. B. Robotic System—Table. Embodiments of the robotically-enabled medical system may also incorporate the patient's table. Incorporation of the table reduces the amount of capital equipment within the operating room by removing the cart, which allows greater access to the patient.FIG.5illustrates an embodiment of such a robotically-enabled system arranged for a bronchoscopy procedure. System36includes a support structure or column37for supporting platform38(shown as a “table” or “bed”) over the floor. Much like in the cart-based systems, the end effectors of the robotic arms39of the system36comprise instrument drivers42that are designed to manipulate an elongated medical instrument, such as a bronchoscope40inFIG.5, through or along a virtual rail41formed from the linear alignment of the instrument drivers42. In practice, a C-arm for providing fluoroscopic imaging may be positioned over the patient's upper abdominal area by placing the emitter and detector around table38. FIG.6provides an alternative view of the system36without the patient and medical instrument for discussion purposes. As shown, the column37may include one or more carriages43shown as ring-shaped in the system36, from which the one or more robotic arms39may be based. The carriages43may translate along a vertical column interface44that runs the length of the column37to provide different vantage points from which the robotic arms39may be positioned to reach the patient. The carriage(s)43may rotate around the column37using a mechanical motor positioned within the column37to allow the robotic arms39to have access to multiples sides of the table38, such as, for example, both sides of the patient. In embodiments with multiple carriages, the carriages may be individually positioned on the column and may translate and/or rotate independent of the other carriages. While carriages43need not surround the column37or even be circular, the ring-shape as shown facilitates rotation of the carriages43around the column37while maintaining structural balance. Rotation and translation of the carriages43allows the system to align the medical instruments, such as endoscopes and laparoscopes, into different access points on the patient. In other embodiments (not shown), the system36can include a patient table or bed with adjustable arm supports in the form of bars or rails extending alongside it. One or more robotic arms39(e.g., via a shoulder with an elbow joint) can be attached to the adjustable arm supports, which can be vertically adjusted. By providing vertical adjustment, the robotic arms39are advantageously capable of being stowed compactly beneath the patient table or bed, and subsequently raised during a procedure. The arms39may be mounted on the carriages through a set of arm mounts45comprising a series of joints that may individually rotate and/or telescopically extend to provide additional configurability to the robotic arms39. Additionally, the arm mounts45may be positioned on the carriages43such that, when the carriages43are appropriately rotated, the arm mounts45may be positioned on either the same side of table38(as shown inFIG.6), on opposite sides of table38(as shown inFIG.9), or on adjacent sides of the table38(not shown). The column37structurally provides support for the table38, and a path for vertical translation of the carriages. Internally, the column37may be equipped with lead screws for guiding vertical translation of the carriages, and motors to mechanize the translation of said carriages based the lead screws. The column37may also convey power and control signals to the carriage43and robotic arms39mounted thereon. The table base46serves a similar function as the cart base15in cart11shown inFIG.2, housing heavier components to balance the table/bed38, the column37, the carriages43, and the robotic arms39. The table base46may also incorporate rigid casters to provide stability during procedures. Deployed from the bottom of the table base46, the casters may extend in opposite directions on both sides of the base46and retract when the system36needs to be moved. Continuing withFIG.6, the system36may also include a tower (not shown) that divides the functionality of system36between table and tower to reduce the form factor and bulk of the table. As in earlier disclosed embodiments, the tower may provide a variety of support functionalities to table, such as processing, computing, and control capabilities, power, fluidics, and/or optical and sensor processing. The tower may also be movable to be positioned away from the patient to improve physician access and de-clutter the operating room. Additionally, placing components in the tower allows for more storage space in the table base for potential stowage of the robotic arms. The tower may also include a master controller or console that provides both a user interface for user input, such as keyboard and/or pendant, as well as a display screen (or touchscreen) for pre-operative and intra-operative information, such as real-time imaging, navigation, and tracking information. In some embodiments, the tower may also contain holders for gas tanks to be used for insufflation. In some embodiments, a table base may stow and store the robotic arms when not in use.FIG.7illustrates a system47that stows robotic arms in an embodiment of the table-based system. In system47, carriages48may be vertically translated into base49to stow robotic arms50, arm mounts51, and the carriages48within the base49. Base covers52may be translated and retracted open to deploy the carriages48, arm mounts51, and arms50around column53, and closed to stow to protect them when not in use. The base covers52may be sealed with a membrane54along the edges of its opening to prevent dirt and fluid ingress when closed. FIG.8illustrates an embodiment of a robotically-enabled table-based system configured for a ureteroscopy procedure. In a ureteroscopy, the table38may include a swivel portion55for positioning a patient off-angle from the column37and table base46. The swivel portion55may rotate or pivot around a pivot point (e.g., located below the patient's head) in order to position the bottom portion of the swivel portion55away from the column37. For example, the pivoting of the swivel portion55allows a C-arm (not shown) to be positioned over the patient's lower abdomen without competing for space with the column (not shown) below table38. By rotating the carriage35(not shown) around the column37, the robotic arms39may directly insert a ureteroscope56along a virtual rail57into the patient's groin area to reach the urethra. In a ureteroscopy, stirrups58may also be fixed to the swivel portion55of the table38to support the position of the patient's legs during the procedure and allow clear access to the patient's groin area. In a laparoscopic procedure, through small incision(s) in the patient's abdominal wall, minimally invasive instruments may be inserted into the patient's anatomy. In some embodiments, the minimally invasive instruments comprise an elongated rigid member, such as a shaft, which is used to access anatomy within the patient. After inflation of the patient's abdominal cavity, the instruments may be directed to perform surgical or medical tasks, such as grasping, cutting, ablating, suturing, etc. In some embodiments, the instruments can comprise a scope, such as a laparoscope.FIG.9illustrates an embodiment of a robotically-enabled table-based system configured for a laparoscopic procedure. As shown inFIG.9, the carriages43of the system36may be rotated and vertically adjusted to position pairs of the robotic arms39on opposite sides of the table38, such that instrument59may be positioned using the arm mounts45to be passed through minimal incisions on both sides of the patient to reach his/her abdominal cavity. To accommodate laparoscopic procedures, the robotically-enabled table system may also tilt the platform to a desired angle.FIG.10illustrates an embodiment of the robotically-enabled medical system with pitch or tilt adjustment. As shown inFIG.10, the system36may accommodate tilt of the table38to position one portion of the table at a greater distance from the floor than the other. Additionally, the arm mounts45may rotate to match the tilt such that the arms39maintain the same planar relationship with table38. To accommodate steeper angles, the column37may also include telescoping portions60that allow vertical extension of column37to keep the table38from touching the floor or colliding with base46. FIG.11provides a detailed illustration of the interface between the table38and the column37. Pitch rotation mechanism61may be configured to alter the pitch angle of the table38relative to the column37in multiple degrees of freedom. The pitch rotation mechanism61may be enabled by the positioning of orthogonal axes1,2at the column-table interface, each axis actuated by a separate motor3,4responsive to an electrical pitch angle command. Rotation along one screw5would enable tilt adjustments in one axis1, while rotation along the other screw6would enable tilt adjustments along the other axis2. In some embodiments, a ball joint can be used to alter the pitch angle of the table38relative to the column37in multiple degrees of freedom. For example, pitch adjustments are particularly useful when trying to position the table in a Trendelenburg position, i.e., position the patient's lower abdomen at a higher position from the floor than the patient's lower abdomen, for lower abdominal surgery. The Trendelenburg position causes the patient's internal organs to slide towards his/her upper abdomen through the force of gravity, clearing out the abdominal cavity for minimally invasive tools to enter and perform lower abdominal surgical or medical procedures, such as laparoscopic prostatectomy. FIGS.12and13illustrate isometric and end views of an alternative embodiment of a table-based surgical robotics system100. The surgical robotics system100includes one or more adjustable arm supports105that can be configured to support one or more robotic arms (see, for example,FIG.14) relative to a table101. In the illustrated embodiment, a single adjustable arm support105is shown, though an additional arm support can be provided on an opposite side of the table101. The adjustable arm support105can be configured so that it can move relative to the table101to adjust and/or vary the position of the adjustable arm support105and/or any robotic arms mounted thereto relative to the table101. For example, the adjustable arm support105may be adjusted one or more degrees of freedom relative to the table101. The adjustable arm support105provides high versatility to the system100, including the ability to easily stow the one or more adjustable arm supports105and any robotics arms attached thereto beneath the table101. The adjustable arm support105can be elevated from the stowed position to a position below an upper surface of the table101. In other embodiments, the adjustable arm support105can be elevated from the stowed position to a position above an upper surface of the table101. The adjustable arm support105can provide several degrees of freedom, including lift, lateral translation, tilt, etc. In the illustrated embodiment ofFIGS.12and13, the arm support105is configured with four degrees of freedom, which are illustrated with arrows inFIG.12. A first degree of freedom allows for adjustment of the adjustable arm support105in the z-direction (“Z-lift”). For example, the adjustable arm support105can include a carriage109configured to move up or down along or relative to a column102supporting the table101. A second degree of freedom can allow the adjustable arm support105to tilt. For example, the adjustable arm support105can include a rotary joint, which can allow the adjustable arm support105to be aligned with the bed in a Trendelenburg position. A third degree of freedom can allow the adjustable arm support105to “pivot up,” which can be used to adjust a distance between a side of the table101and the adjustable arm support105. A fourth degree of freedom can permit translation of the adjustable arm support105along a longitudinal length of the table. The surgical robotics system100inFIGS.12and13can comprise a table supported by a column102that is mounted to a base103. The base103and the column102support the table101relative to a support surface. A floor axis131and a support axis133are shown inFIG.13. The adjustable arm support105can be mounted to the column102. In other embodiments, the arm support105can be mounted to the table101or base103. The adjustable arm support105can include a carriage109, a bar or rail connector111and a bar or rail107. In some embodiments, one or more robotic arms mounted to the rail107can translate and move relative to one another. The carriage109can be attached to the column102by a first joint113, which allows the carriage109to move relative to the column102(e.g., such as up and down a first or vertical axis123). The first joint113can provide the first degree of freedom (Z-lift) to the adjustable arm support105. The adjustable arm support105can include a second joint115, which provides the second degree of freedom (tilt) for the adjustable arm support105. The adjustable arm support105can include a third joint117, which can provide the third degree of freedom (“pivot up”) for the adjustable arm support105. An additional joint119(shown inFIG.13) can be provided that mechanically constrains the third joint117to maintain an orientation of the rail107as the rail connector111is rotated about a third axis127. The adjustable arm support105can include a fourth joint121, which can provide a fourth degree of freedom (translation) for the adjustable arm support105along a fourth axis129. FIG.14illustrates an end view of the surgical robotics system140A with two adjustable arm supports105A,105B mounted on opposite sides of a table101. A first robotic arm142A is attached to the bar or rail107A of the first adjustable arm support105B. The first robotic arm142A includes a base144A attached to the rail107A. The distal end of the first robotic arm142A includes an instrument drive mechanism146A that can attach to one or more robotic medical instruments or tools. Similarly, the second robotic arm142B includes a base144B attached to the rail107B. The distal end of the second robotic arm142B includes an instrument drive mechanism146B. The instrument drive mechanism146B can be configured to attach to one or more robotic medical instruments or tools. In some embodiments, one or more of the robotic arms142A,142B comprises an arm with seven or more degrees of freedom. In some embodiments, one or more of the robotic arms142A,142B can include eight degrees of freedom, including an insertion axis (1-degree of freedom including insertion), a wrist (3-degrees of freedom including wrist pitch, yaw and roll), an elbow (1-degree of freedom including elbow pitch), a shoulder (2-degrees of freedom including shoulder pitch and yaw), and base144A,144B (1-degree of freedom including translation). In some embodiments, the insertion degree of freedom can be provided by the robotic arm142A,142B, while in other embodiments, the instrument itself provides insertion via an instrument-based insertion architecture. C. Instrument Driver & Interface. The end effectors of the system's robotic arms comprise (i) an instrument driver (alternatively referred to as “instrument drive mechanism” or “instrument device manipulator”) that incorporate electro-mechanical means for actuating the medical instrument and (ii) a removable or detachable medical instrument, which may be devoid of any electro-mechanical components, such as motors. This dichotomy may be driven by the need to sterilize medical instruments used in medical procedures, and the inability to adequately sterilize expensive capital equipment due to their intricate mechanical assemblies and sensitive electronics. Accordingly, the medical instruments may be designed to be detached, removed, and interchanged from the instrument driver (and thus the system) for individual sterilization or disposal by the physician or the physician's staff. In contrast, the instrument drivers need not be changed or sterilized, and may be draped for protection. FIG.15illustrates an example instrument driver. Positioned at the distal end of a robotic arm, instrument driver62comprises of one or more drive units63arranged with parallel axes to provide controlled torque to a medical instrument via drive shafts64. Each drive unit63comprises an individual drive shaft64for interacting with the instrument, a gear head65for converting the motor shaft rotation to a desired torque, a motor66for generating the drive torque, an encoder67to measure the speed of the motor shaft and provide feedback to the control circuitry, and control circuity68for receiving control signals and actuating the drive unit. Each drive unit63being independent controlled and motorized, the instrument driver62may provide multiple (four as shown inFIG.15) independent drive outputs to the medical instrument. In operation, the control circuitry68would receive a control signal, transmit a motor signal to the motor66, compare the resulting motor speed as measured by the encoder67with the desired speed, and modulate the motor signal to generate the desired torque. For procedures that require a sterile environment, the robotic system may incorporate a drive interface, such as a sterile adapter connected to a sterile drape, that sits between the instrument driver and the medical instrument. The chief purpose of the sterile adapter is to transfer angular motion from the drive shafts of the instrument driver to the drive inputs of the instrument while maintaining physical separation, and thus sterility, between the drive shafts and drive inputs. Accordingly, an example sterile adapter may comprise of a series of rotational inputs and outputs intended to be mated with the drive shafts of the instrument driver and drive inputs on the instrument. Connected to the sterile adapter, the sterile drape, comprised of a thin, flexible material such as transparent or translucent plastic, is designed to cover the capital equipment, such as the instrument driver, robotic arm, and cart (in a cart-based system) or table (in a table-based system). Use of the drape would allow the capital equipment to be positioned proximate to the patient while still being located in an area not requiring sterilization (i.e., non-sterile field). On the other side of the sterile drape, the medical instrument may interface with the patient in an area requiring sterilization (i.e., sterile field). D. Medical Instrument. FIG.16illustrates an example medical instrument with a paired instrument driver. Like other instruments designed for use with a robotic system, medical instrument70comprises an elongated shaft71(or elongate body) and an instrument base72. The instrument base72, also referred to as an “instrument handle” due to its intended design for manual interaction by the physician, may generally comprise rotatable drive inputs73, e.g., receptacles, pulleys or spools, that are designed to be mated with drive outputs74that extend through a drive interface on instrument driver75at the distal end of robotic arm76. When physically connected, latched, and/or coupled, the mated drive inputs73of instrument base72may share axes of rotation with the drive outputs74in the instrument driver75to allow the transfer of torque from drive outputs74to drive inputs73. In some embodiments, the drive outputs74may comprise splines that are designed to mate with receptacles on the drive inputs73. The elongated shaft71is designed to be delivered through either an anatomical opening or lumen, e.g., as in endoscopy, or a minimally invasive incision, e.g., as in laparoscopy. The elongated shaft71may be either flexible (e.g., having properties similar to an endoscope) or rigid (e.g., having properties similar to a laparoscope) or contain a customized combination of both flexible and rigid portions. When designed for laparoscopy, the distal end of a rigid elongated shaft may be connected to an end effector extending from a jointed wrist formed from a clevis with at least one degree of freedom and a surgical tool or medical instrument, such as, for example, a grasper or scissors, that may be actuated based on force from the tendons as the drive inputs rotate in response to torque received from the drive outputs74of the instrument driver75. When designed for endoscopy, the distal end of a flexible elongated shaft may include a steerable or controllable bending section that may be articulated and bent based on torque received from the drive outputs74of the instrument driver75. Torque from the instrument driver75is transmitted down the elongated shaft71using tendons along the shaft71. These individual tendons, such as pull wires, may be individually anchored to individual drive inputs73within the instrument handle72. From the handle72, the tendons are directed down one or more pull lumens along the elongated shaft71and anchored at the distal portion of the elongated shaft71, or in the wrist at the distal portion of the elongated shaft. During a surgical procedure, such as a laparoscopic, endoscopic or hybrid procedure, these tendons may be coupled to a distally mounted end effector, such as a wrist, grasper, or scissor. Under such an arrangement, torque exerted on drive inputs73would transfer tension to the tendon, thereby causing the end effector to actuate in some way. In some embodiments, during a surgical procedure, the tendon may cause a joint to rotate about an axis, thereby causing the end effector to move in one direction or another. Alternatively, the tendon may be connected to one or more jaws of a grasper at distal end of the elongated shaft71, where tension from the tendon cause the grasper to close. In endoscopy, the tendons may be coupled to a bending or articulating section positioned along the elongated shaft71(e.g., at the distal end) via adhesive, control ring, or other mechanical fixation. When fixedly attached to the distal end of a bending section, torque exerted on drive inputs73would be transmitted down the tendons, causing the softer, bending section (sometimes referred to as the articulable section or region) to bend or articulate. Along the non-bending sections, it may be advantageous to spiral or helix the individual pull lumens that direct the individual tendons along (or inside) the walls of the endoscope shaft to balance the radial forces that result from tension in the pull wires. The angle of the spiraling and/or spacing there between may be altered or engineered for specific purposes, wherein tighter spiraling exhibits lesser shaft compression under load forces, while lower amounts of spiraling results in greater shaft compression under load forces, but also exhibits limits bending. On the other end of the spectrum, the pull lumens may be directed parallel to the longitudinal axis of the elongated shaft71to allow for controlled articulation in the desired bending or articulable sections. In endoscopy, the elongated shaft71houses a number of components to assist with the robotic procedure. The shaft may comprise of a working channel for deploying surgical tools (or medical instruments), irrigation, and/or aspiration to the operative region at the distal end of the shaft71. The shaft71may also accommodate wires and/or optical fibers to transfer signals to/from an optical assembly at the distal tip, which may include of an optical camera. The shaft71may also accommodate optical fibers to carry light from proximally-located light sources, such as light emitting diodes, to the distal end of the shaft. At the distal end of the instrument70, the distal tip may also comprise the opening of a working channel for delivering tools for diagnostic and/or therapy, irrigation, and aspiration to an operative site. The distal tip may also include a port for a camera, such as a fiberscope or a digital camera, to capture images of an internal anatomical space. Relatedly, the distal tip may also include ports for light sources for illuminating the anatomical space when using the camera. In the example ofFIG.16, the drive shaft axes, and thus the drive input axes, are orthogonal to the axis of the elongated shaft. This arrangement, however, complicates roll capabilities for the elongated shaft71. Rolling the elongated shaft71along its axis while keeping the drive inputs73static results in undesirable tangling of the tendons as they extend off the drive inputs73and enter pull lumens within the elongated shaft71. The resulting entanglement of such tendons may disrupt any control algorithms intended to predict movement of the flexible elongated shaft during an endoscopic procedure. FIG.17illustrates an alternative design for an instrument driver and instrument where the axes of the drive units are parallel to the axis of the elongated shaft of the instrument. As shown, a circular instrument driver80comprises four drive units with their drive outputs81aligned in parallel at the end of a robotic arm82. The drive units, and their respective drive outputs81, are housed in a rotational assembly83of the instrument driver80that is driven by one of the drive units within the assembly83. In response to torque provided by the rotational drive unit, the rotational assembly83rotates along a circular bearing that connects the rotational assembly83to the non-rotational portion84of the instrument driver. Power and controls signals may be communicated from the non-rotational portion84of the instrument driver80to the rotational assembly83through electrical contacts may be maintained through rotation by a brushed slip ring connection (not shown). In other embodiments, the rotational assembly83may be responsive to a separate drive unit that is integrated into the non-rotatable portion84, and thus not in parallel to the other drive units. The rotational mechanism83allows the instrument driver80to rotate the drive units, and their respective drive outputs81, as a single unit around an instrument driver axis85. Like earlier disclosed embodiments, an instrument86may comprise an elongated shaft portion88and an instrument base87(shown with a transparent external skin for discussion purposes) comprising a plurality of drive inputs89(such as receptacles, pulleys, and spools) that are configured to receive the drive outputs81in the instrument driver80. Unlike prior disclosed embodiments, instrument shaft88extends from the center of instrument base87with an axis substantially parallel to the axes of the drive inputs89, rather than orthogonal as in the design ofFIG.16. When coupled to the rotational assembly83of the instrument driver80, the medical instrument86, comprising instrument base87and instrument shaft88, rotates in combination with the rotational assembly83about the instrument driver axis85. Since the instrument shaft88is positioned at the center of instrument base87, the instrument shaft88is coaxial with instrument driver axis85when attached. Thus, rotation of the rotational assembly83causes the instrument shaft88to rotate about its own longitudinal axis. Moreover, as the instrument base87rotates with the instrument shaft88, any tendons connected to the drive inputs89in the instrument base87are not tangled during rotation. Accordingly, the parallelism of the axes of the drive outputs81, drive inputs89, and instrument shaft88allows for the shaft rotation without tangling any control tendons. FIG.18illustrates an instrument having an instrument based insertion architecture in accordance with some embodiments. The instrument150can be coupled to any of the instrument drivers discussed above. The instrument150comprises an elongated shaft152, an end effector162connected to the shaft152, and a handle170coupled to the shaft152. The elongated shaft152comprises a tubular member having a proximal portion154and a distal portion156. The elongated shaft152comprises one or more channels or grooves158along its outer surface. The grooves158are configured to receive one or more wires or cables180therethrough. One or more cables180thus run along an outer surface of the elongated shaft152. In other embodiments, cables180can also run through the elongated shaft152. Manipulation of the one or more cables180(e.g., via an instrument driver) results in actuation of the end effector162. The instrument handle170, which may also be referred to as an instrument base, may generally comprise an attachment interface172having one or more mechanical inputs174, e.g., receptacles, pulleys or spools, that are designed to be reciprocally mated with one or more torque couplers on an attachment surface of an instrument driver. In some embodiments, the instrument150comprises a series of pulleys or cables that enable the elongated shaft152to translate relative to the handle170. In other words, the instrument150itself comprises an instrument-based insertion architecture that accommodates insertion of the instrument, thereby minimizing the reliance on a robot arm to provide insertion of the instrument150. In other embodiments, a robotic arm can be largely responsible for instrument insertion. E. Controller. Any of the robotic systems described herein can include an input device or controller for manipulating an instrument attached to a robotic arm. In some embodiments, the controller can be coupled (e.g., communicatively, electronically, electrically, wirelessly and/or mechanically) with an instrument such that manipulation of the controller causes a corresponding manipulation of the instrument e.g., via master slave control. FIG.19is a perspective view of an embodiment of a controller182. In the present embodiment, the controller182comprises a hybrid controller that can have both impedance and admittance control. In other embodiments, the controller182can utilize just impedance or passive control. In other embodiments, the controller182can utilize just admittance control. By being a hybrid controller, the controller182advantageously can have a lower perceived inertia while in use. In the illustrated embodiment, the controller182is configured to allow manipulation of two medical instruments, and includes two handles184. Each of the handles184is connected to a gimbal186. Each gimbal186is connected to a positioning platform188. As shown inFIG.19, each positioning platform188includes a SCARA arm (selective compliance assembly robot arm)198coupled to a column194by a prismatic joint196. The prismatic joints196are configured to translate along the column194(e.g., along rails197) to allow each of the handles184to be translated in the z-direction, providing a first degree of freedom. The SCARA arm198is configured to allow motion of the handle184in an x-y plane, providing two additional degrees of freedom. In some embodiments, one or more load cells are positioned in the controller. For example, in some embodiments, a load cell (not shown) is positioned in the body of each of the gimbals186. By providing a load cell, portions of the controller182are capable of operating under admittance control, thereby advantageously reducing the perceived inertia of the controller while in use. In some embodiments, the positioning platform188is configured for admittance control, while the gimbal186is configured for impedance control. In other embodiments, the gimbal186is configured for admittance control, while the positioning platform188is configured for impedance control. Accordingly, for some embodiments, the translational or positional degrees of freedom of the positioning platform188can rely on admittance control, while the rotational degrees of freedom of the gimbal186rely on impedance control. F. Navigation and Control. Traditional endoscopy may involve the use of fluoroscopy (e.g., as may be delivered through a C-arm) and other forms of radiation-based imaging modalities to provide endoluminal guidance to an operator physician. In contrast, the robotic systems contemplated by this disclosure can provide for non-radiation-based navigational and localization means to reduce physician exposure to radiation and reduce the amount of equipment within the operating room. As used herein, the term “localization” may refer to determining and/or monitoring the position of objects in a reference coordinate system. Technologies such as pre-operative mapping, computer vision, real-time EM tracking, and robot command data may be used individually or in combination to achieve a radiation-free operating environment. In other cases, where radiation-based imaging modalities are still used, the pre-operative mapping, computer vision, real-time EM tracking, and robot command data may be used individually or in combination to improve upon the information obtained solely through radiation-based imaging modalities. FIG.20is a block diagram illustrating a localization system90that estimates a location of one or more elements of the robotic system, such as the location of the instrument, in accordance to an example embodiment. The localization system90may be a set of one or more computer devices configured to execute one or more instructions. The computer devices may be embodied by a processor (or processors) and computer-readable memory in one or more components discussed above. By way of example and not limitation, the computer devices may be in the tower30shown inFIG.1, the cart shown inFIGS.1-4, the beds shown inFIGS.5-14, etc. As shown inFIG.20, the localization system90may include a localization module95that processes input data91-94to generate location data96for the distal tip of a medical instrument. The location data96may be data or logic that represents a location and/or orientation of the distal end of the instrument relative to a frame of reference. The frame of reference can be a frame of reference relative to the anatomy of the patient or to a known object, such as an EM field generator (see discussion below for the EM field generator). The various input data91-94are now described in greater detail. Pre-operative mapping may be accomplished through the use of the collection of low dose CT scans. Pre-operative CT scans are reconstructed into three-dimensional images, which are visualized, e.g. as “slices” of a cutaway view of the patient's internal anatomy. When analyzed in the aggregate, image-based models for anatomical cavities, spaces and structures of the patient's anatomy, such as a patient lung network, may be generated. Techniques such as center-line geometry may be determined and approximated from the CT images to develop a three-dimensional volume of the patient's anatomy, referred to as model data91(also referred to as “preoperative model data” when generated using only preoperative CT scans). The use of center-line geometry is discussed in U.S. patent application Ser. No. 14/523,760, the contents of which are herein incorporated in its entirety. Network topological models may also be derived from the CT-images, and are particularly appropriate for bronchoscopy. In some embodiments, the instrument may be equipped with a camera to provide vision data92. The localization module95may process the vision data to enable one or more vision-based location tracking. For example, the preoperative model data may be used in conjunction with the vision data92to enable computer vision-based tracking of the medical instrument (e.g., an endoscope or an instrument advance through a working channel of the endoscope). For example, using the preoperative model data91, the robotic system may generate a library of expected endoscopic images from the model based on the expected path of travel of the endoscope, each image linked to a location within the model. Intra-operatively, this library may be referenced by the robotic system in order to compare real-time images captured at the camera (e.g., a camera at a distal end of the endoscope) to those in the image library to assist localization. Other computer vision-based tracking techniques use feature tracking to determine motion of the camera, and thus the endoscope. Some features of the localization module95may identify circular geometries in the preoperative model data91that correspond to anatomical lumens and track the change of those geometries to determine which anatomical lumen was selected, as well as the relative rotational and/or translational motion of the camera. Use of a topological map may further enhance vision-based algorithms or techniques. Optical flow, another computer vision-based technique, may analyze the displacement and translation of image pixels in a video sequence in the vision data92to infer camera movement. Examples of optical flow techniques may include motion detection, object segmentation calculations, luminance, motion compensated encoding, stereo disparity measurement, etc. Through the comparison of multiple frames over multiple iterations, movement and location of the camera (and thus the endoscope) may be determined. The localization module95may use real-time EM tracking to generate a real-time location of the endoscope in a global coordinate system that may be registered to the patient's anatomy, represented by the preoperative model. In EM tracking, an EM sensor (or tracker) comprising of one or more sensor coils embedded in one or more locations and orientations in a medical instrument (e.g., an endoscopic tool) measures the variation in the EM field created by one or more static EM field generators positioned at a known location. The location information detected by the EM sensors is stored as EM data93. The EM field generator (or transmitter), may be placed close to the patient to create a low intensity magnetic field that the embedded sensor may detect. The magnetic field induces small currents in the sensor coils of the EM sensor, which may be analyzed to determine the distance and angle between the EM sensor and the EM field generator. These distances and orientations may be intra-operatively “registered” to the patient anatomy (e.g., the preoperative model) in order to determine the geometric transformation that aligns a single location in the coordinate system with a position in the pre-operative model of the patient's anatomy. Once registered, an embedded EM tracker in one or more positions of the medical instrument (e.g., the distal tip of an endoscope) may provide real-time indications of the progression of the medical instrument through the patient's anatomy. Robotic command and kinematics data94may also be used by the localization module95to provide localization data96for the robotic system. Device pitch and yaw resulting from articulation commands may be determined during pre-operative calibration. Intra-operatively, these calibration measurements may be used in combination with known insertion depth information to estimate the position of the instrument. Alternatively, these calculations may be analyzed in combination with EM, vision, and/or topological modeling to estimate the position of the medical instrument within the network. AsFIG.20shows, a number of other input data can be used by the localization module95. For example, although not shown inFIG.20, an instrument utilizing shape-sensing fiber can provide shape data that the localization module95can use to determine the location and shape of the instrument. The localization module95may use the input data91-94in combination(s). In some cases, such a combination may use a probabilistic approach where the localization module95assigns a confidence weight to the location determined from each of the input data91-94. Thus, where the EM data may not be reliable (as may be the case where there is EM interference) the confidence of the location determined by the EM data93can be decrease and the localization module95may rely more heavily on the vision data92and/or the robotic command and kinematics data94. As discussed above, the robotic systems discussed herein may be designed to incorporate a combination of one or more of the technologies above. The robotic system's computer-based control system, based in the tower, bed and/or cart, may store computer program instructions, for example, within a non-transitory computer-readable storage medium such as a persistent magnetic storage drive, solid state drive, or the like, that, upon execution, cause the system to receive and analyze sensor data and user commands, generate control signals throughout the system, and display the navigational and localization data, such as the position of the instrument within the global coordinate system, anatomical map, etc. 2. Introduction to Robotically Controlled Clot Manipulation and Removal. Embodiments of the disclosure relate to systems and methods for robotically controlled clot manipulation and removal. Acute ischemic strokes present a major health issue facing the general populace. These strokes can be caused by large vessel occlusions due to clots formed in blood vessels. Current procedures for clot removal are performed manually by a vascular/neurovascular surgeon that has to navigate a tortuous path to access cerebrovasculature. These manual procedures can face a number of challenges, including incomplete clot removal (25% of cases), multiple catheter passes (50% of cases), emboli disruption, and vessel dissection/perforation. In addition, the time for performing such a procedure can be quite long, with the result being rapid loss of neurons as each minute passes. Furthermore, in addition to a vascular surgeon, multiple other personnel may be needed to complete a stroke procedure, including neurologists, radiologists, nurses and catheter lab clinicians, thereby consuming a large number of resources. Often times, physicians who are capable of performing stroke care are often in limited supply or not readily available at a time of need for a patient seeking treatment. Embodiments described herein cover systems and methods for robotically controlled manipulation and removal of clots that address issues described above. The systems are configured such that at least a portion of the clot removal procedure can be performed robotically, thereby making clot removal more accurate and faster to perform. While the systems and methods described herein often refer to clots in the cerebrovasculature, one skilled in the art will appreciate that the systems and methods described can also apply to clots found anywhere in the body, including in the peripheral and pulmonary arteries. A. Robotic Systems for Performing Clot Removal. Robotic systems for performing clot removal will now be described. These systems can be used to control at least some portion of a clot removal instrument robotically. As shown inFIGS.26-29C, clot removal instruments can take many forms, and can include multiple elongate members, including one or more sheaths, catheters, disruptors and guidewires. In some embodiments, the robotic systems can be used to navigate, steer and/or articulate one or more of these sheaths, catheters, disruptors and guidewires robotically via telemanipulation. FIG.21illustrates an embodiment of a robotic system200for performing clot removal. The robotic system200comprises a console220, a processor240, a patient platform201and an instrument drive system250. The instrument drive system250is configured to manipulate a clot removal instrument300through a patient to remove a clot e.g., in cerebrovasculature, in peripheral vasculature or in a pulmonary vessel. While the application refers to reference numeral300as a clot removal instrument composed of multiple components (e.g., elongate members), one skilled in the art can appreciate that reference numeral300can also be viewed alternatively as a clot removal system comprised of a number of elongate instruments therein. As shown inFIG.21, a patient is configured to reside on a patient platform201. The patient platform201can be in the form of a bed that is capable of tilting in multiple degrees of freedom. For example, in some embodiments, the bed is capable of Trendelenburg tilt and/or lateral tilt. The patient platform201is capable of support an instrument drive system250. In some embodiments, the patient platform201is capable of support a pair of instrument drive systems250. The instrument drive system250comprises a set-up arm including a set-up joint260and an instrument driver270. The instrument driver270comprises a base269that supports a proximal instrument driver271and a distal instrument driver273for driving instruments attached thereto via drive shafts (similar to the driver shown inFIG.15). The proximal instrument driver271is connected to a proximal instrument splayer or handle272of the clot removal instrument300, while the distal instrument driver273is connected to a distal instrument splayer or handle274of the clot removal instrument300. In some embodiments, the proximal instrument driver271and distal instrument driver273are capable of aligning and/or translating relative to each other, such as along a track or rail. In other embodiments, the proximal instrument driver271and distal instrument driver273are capable of aligning and/or translating relative to each other via a virtual track via algorithm. The clot removal instrument300comprises one or more elongate members capable of robotic control. In some embodiments, the one or more elongate members can be used for any of the following functions, including access, navigation, irrigation, suction, clot modification, and/or removal. In some embodiments, the clot removal instrument300can comprise a telescoping sheath or catheter that can serve as a conduit for a clot modifying or removal device that can remove a clot via any combination of aspiration, stent deployment, energy delivery, or drug delivery. In some embodiments, the clot removal instrument300can comprise at least one elongate member coupled to a proximal instrument handle272and at least one elongate member coupled to a distal instrument handle274. As noted above, the proximal instrument handle272is connected to a proximal instrument driver271, while the distal instrument handle274is connected to a distal instrument driver273, thereby enabling driving and articulation of the respective elongate members. The clot removal instrument300can be remotely and/or teleoperatively operated via a physician or clinician. The physician can be positioned at a console station220that includes one or more viewing screens210and a controller230. The controller230can be used to drive, manipulate, and articulate the clot removal instrument300. In some embodiments, the controller230can be in the form of a joystick, a pendant, or a gimbal. Advantageously, the viewing screens210can present one or more views to the user to assist in the navigation of the clot removal instrument300, including but not limited to first-person, third-person, picture-in-picture, zoomed-out, and isometric views of the clot removal instrument300within a vessel. In addition, the viewing screens210can be touch screens whereby the user can interact with the screens to switch between images, modify image quality, and perform any other function to assist in imaging and navigation. As the physician manipulates the controller230, signals are sent to a processor240, which then controls movement of the clot removal instrument300. FIG.22illustrates a drive system250of the robotic system ofFIG.21for performing clot removal within a patient's vasculature5. As shown in this figure, the drive system250can be coupled to a clot removal instrument300via its proximal and distal handles272,274, which are capable of translating relative to one another (e.g., via a rail, track or virtually). The clot removal instrument300is configured to extend through an incision formed in the patient. In some embodiments, the clot removal instrument300enters into a patient via the groin or femoral artery, as shown inFIG.22. In other embodiments, the clot removal instrument300enters into a patient radially or peripherally, such as through an incision along or near a patient's arm. The drive system250is capable of navigating the clot removal instrument300through vessels that can extend into the cerebrovasculature of the patient. As shown inFIG.22, the vessels can reduce in size from the femoral region to the brain region. Advantageously, the clot removal instrument300is designed to have features for conveniently navigating vessels that reduce in size, as will be discussed further below. FIG.23illustrates a drive system250of the robotic system ofFIG.21. From this view, one can see the base269of the drive system250including a proximal instrument driver271for driving an elongated instrument attached to a proximal instrument splayer or handle272and a distal instrument driver273for driving an elongated instrument attached to a distal instrument splayer or handle274. In some embodiments, the elongated instrument attached to the proximal instrument handle272comprises an aspiration catheter, while the elongate instrument attached to the distal instrument handle274comprises an access sheath through which the aspiration catheter translates. In other embodiments, the elongate instrument attached to the proximal instrument handle272comprises an access catheter, while the elongate instrument attached to the distal instrument handle274comprises an access sheath that is capable of telescoping relative to the access catheter to provide a conduit and/or working channel for other instruments that serve as a clot remover (e.g., a clot retriever, aspiration catheter, or other mechanical thrombectomy device). In some embodiments, a sterile adapter can be positioned between the proximal and distal instrument handles and their respective drivers. In some embodiments, at least one of the proximal instrument driver271and the distal instrument driver273is capable of movement or translation. In some embodiments, both of the proximal instrument driver271and the distal instrument driver273are capable of movement or translation. In the present embodiment, the proximal instrument driver271is fixed, while the distal instrument driver273is capable of translation. As shown inFIG.23, at least one of the proximal instrument driver271and the distal instrument driver273is capable of translation along a track or rail279of the drive system250. In other embodiments, such as shown inFIG.41, instrument drivers can be positioned on robotic arms that align along a virtual rail, such that there is no physical track or rail for translation. FIG.41illustrates an embodiment of a dual robotic system250a,250bfor performing clot removal. The dual robotic system250a,250bcomprises a first robotic system250aand a second robotic system250b, each of which is similar to the robotic system250shown inFIG.21. The first robotic system250aincludes a proximal instrument driver271afor driving a first elongate member attached thereto and a distal instrument driver273afor driving a second elongate member attached thereto. Similarly, the second robotic system250bincludes a proximal instrument driver271bfor driving a third elongate member attached thereto and a distal instrument driver273bfor driving a fourth elongate member attached thereto. Accordingly, by providing the dual robotic system250a,250b, more than two elongate members can be robotically controlled as part of a clot removal procedure. For example, in one embodiment, the distal instrument driver273acan drive an access sheath, the proximal instrument driver271acan drive an aspiration catheter within the access sheath, the distal instrument driver273bcan drive a clot disruptor within the aspiration catheter and the access sheath, and the proximal instrument driver271bcan drive a guidewire within the clot disruptor, aspiration catheter and access sheath. In other embodiments, while the dual robotic system250a,250benables robotic control of at least four elongate members, in some embodiments, not all of the instrument drivers need be used. For example, in some embodiments, the dual robotic system250a,250bcan utilize three of the four drivers273a,271a, and273bto robotically control an access sheath, an aspiration catheter and a guide wire, without having to use the fourth driver. FIG.42illustrates an alternative embodiment of a robotic system500for performing a clot removal. In the present embodiment, the robotic system500comprises a patient platform501(e.g., a bed) for receiving a patient thereon. A mobile cart502having one or more robotic arms512,514,516is capable of being positioned next to the patient platform501. Each of the robotic arms512,514,516includes instrument drivers522,524,526that is capable of driving an elongate member attached thereto. For example, in the present embodiment, the robotic arms512,514,516are capable of driving different elongate members of a clot removal instrument300via the instrument drivers522,524,526. In one embodiment, the robotic arm512and its associated instrument driver522are capable of positioning and driving an access sheath, the robotic arm514and its associated instrument driver524are capable of positioning and driving an aspiration catheter within the access sheath, and the robotic arm516and its associated instrument driver526are capable of positioning and driving a clot disruptor or guidewire within the aspiration catheter and the access sheath. In some embodiments, the instruments drivers522,524,526can be aligned via a “virtual rail” in which the robotic arms512,514,516position them in alignment. Advantageously, as the cart502is mobile, it is capable of being moved to different positions relative to the patient. For example, the cart502can be positioned such that the robotic arms512,514,516can perform a clot removal through a femoral artery of the patient. The cart502can also be positioned such that the robotic arms512,514,516can perform a clot removal through a radial or peripheral entry of the patient on or near an arm of the patient. In addition, one skilled in the art will appreciate that the cart502can include less than (e.g., 2 or less) or more than (e.g., 4 or more) three arms. In addition, a clot removal procedure can be performed using a pair of carts with multiple arms, or using a cart combined with a laparoscopic bed having multiple arms, as described below. FIG.43illustrates a yet another alternative embodiment of a robotic system600for performing a clot removal. The robotic system600comprises a plurality of robotic arms612,614,616,613,615,617that are each coupled to an adjustable arm support605,607similar to those described inFIGS.12and13. As shown in the figure, the robotic system600comprises six robotic arms, in which three612,614,616are coupled to a first adjustable arm support605and another three613,615,617are coupled to a second adjustable arm support607. Each of the robotic arms612,614,616,613,615,617is respectively coupled to an instrument driver622,624,626,623,625,627that is optionally coupled to a sterile adapter. The instrument drivers622,624,626,623,625,627are each capable of attachment to a handle of an instrument, thereby allowing for driving and articulation of the instrument. As the robotic system600includes six robotic arms, there can advantageously be up to six instruments of an instrument system300that can be advantageously controlled. The instruments can include various types of elongate members, including but not limited to one or more access sheaths, clot removal catheters (e.g., aspiration catheters, stent deployment catheters), clot disruptors (e.g., including mechanical disruptors and energy disruptors), laser catheters, water jet catheters, and guide wires. One skilled in the art will appreciate that not all of the arms of the robotic system600need to be used, but that the system provides the option to use all if recommended by a physician. For example, in one embodiment, five of the robotic arms can be used, with the first robotic arm612used to control an wide access sheath (e.g., one that stops at or near the femoral artery), a second robotic arm614used to control a narrower access sheath (e.g., one that stops at or near the carotid artery), a third robotic arm616used to control a clot removal catheter (e.g., capable of moving beyond the carotid artery if needed), a fourth robotic arm613used to control a clot disruptor to reduce the size of the clot, and a fifth robotic arm615used to control a guidewire. In an alternative embodiment, one of the arms can be used to stabilize an instrument system300as it is being inserted into a patient. For example, in one embodiment, first robotic arm612can be used to stabilize an instrument system300as it is inserted through a femur or radially. In some embodiments, the first robotic arm612can serve as and/or be coupled to an introducer that allows for stabile insertion of the instrument system300through an incision. In such an embodiment in which the first robotic arm612is used as an instrument stabilizer, the second robotic arm614can be used to control a wide access sheath (e.g., one that stops at or near the carotid artery), the third robotic arm616can be used to control a narrower access sheath (e.g., one that stops at or near the carotid artery), a fourth robotic arm613can be used to control a clot removal catheter (e.g., capable of moving beyond the carotid artery if needed), a fifth robotic arm615can be used to control a clot disruptor to modify the clot, and a sixth robotic arm617can be used to control a guidewire. Thus, the availability of multiple arms, such as six or more, certainly increases the options for use for a clinician or physician. In the present embodiment, the robotic arms612,614,616are coupled to a first adjustable arm support605, while the robotic arms613,615,617are coupled to a second adjustable arm support607. Each of the arm supports605,607resides on opposing sides of the patient, such that the procedure can be performed bilaterally. Both the first set of robotic arms612,614,616and the second set of robotic arms613,615,617are capable of translating relative to one another. Each of the robotic arms can move in multiple degrees of freedom (e.g., six, seven, eight or more), which advantageously helps to avoid collisions between one another. The robotic systems described herein can be found in hospital and emergency centers. Advantageously, at least some of the systems are mobile such that they can be transported into different rooms. In addition, the robotic systems described herein can also be incorporated into a mobile vehicle, such as an emergency vehicle. This can be particularly useful to patients that may need immediate care that are not close to an emergency center, such as patients in rural areas. One skilled in the art will appreciate that the robotic systems described herein are not limited to performing clot removal. For example, the system shown and described inFIG.43can also be used to perform a concomitant endoscopic and laparoscopic procedure, such as an escalated colon polyp resection. Accordingly, the robotic systems described herein provide great versatility in performing various types of surgeries beyond those described in detail herein. In addition, the robotic systems described herein can be used to treat various maladies, including stroke, myocardial infarction, cardiac arrest, or other types medical issues. B. Instrument Systems for Clot Removal. This section describes various types of instrument systems that can be used for clot removal. While the devices described herein may be referred to as “instruments systems,” as they often include multiple elongate members that may be independently controlled from one another, one skilled in the art can appreciate that they can also be considered simply as “instruments” having multiple independently controlled components. These instrument systems can include one or more elongate members that can be robotically operated, navigated, and/or articulated using any of the systems described herein, such as shown inFIGS.23,41,42, and43. In some embodiments, an instrument system can include multiple elongate members. For example, in one embodiment, an instrument system includes a first elongate member comprising an access sheath, a second elongate member comprising a clot removing (e.g., aspiration) catheter, a third elongate member comprising a clot modifier (e.g., disruptor), and a fourth elongate member comprising a guide wire. At least one or more of the elongate members of the instrument systems can include one or more drive or articulating wires. In some embodiments, one or more elongate members can include four articulating wires. These articulating wires can be spaced evenly relative to one another about a circumference of the elongate member. In other embodiments, one or more of the elongate members can include less than four articulating wires (e.g., such as a three, two or a single articulating wire). By having a relatively small number of articulating wires, this allows an elongate member to have a reduced diameter, which can be advantageous for robotically navigating smaller and smaller vessels. FIG.24illustrates an instrument system300for performing clot removal. The instrument system300comprises a first elongate member304(e.g., an access sheath) and a second elongate member302(e.g., a clot removing catheter such as an aspiration catheter) that extends through a lumen of the first elongate member304. The first elongate member304is coupled to the distal instrument handle274, while the second elongate member302is coupled to the proximal instrument handle272. The distal instrument handle274is configured to articulate the first elongate member304via one or more pull or articulating wires, while the proximal instrument handle272is configured to articulate the second elongate member302via one or more pull or articulating wires. The distal instrument handle274and proximal instrument handle272are configured to removably attach to distal and proximal instrument drivers273,271including motors, drive shafts, and sensors (e.g., torque sensors) as discussed above. These instrument drivers273,271can be found in any of the systems described herein, as shown inFIGS.23,41,42, and43. In some embodiments, the first elongate member304comprises an access sheath. The access sheath serves as a guide that can be parked anywhere along a vessel that leads into cerebrovasculature of the patient. For example, in some embodiments, the first elongate member304comprises an access sheath that can be parked at or near the carotid artery, thereby serving as a conduit for even smaller elongate members to access cerebrovasculature. In some embodiments, the first elongate member304comprises one or more pull or articulating wires to articulate the first elongate member304through tortuous anatomy. In some embodiments, the second elongate member302comprises a clot removing catheter such as an aspiration catheter. The second elongate member302can be used to retain a clot via vacuum or suction. Upon aspiration, the second elongate member302can then be retracted back and out through the vascular system of the patient, thereby removing the clot from the patient. In some embodiments, the second elongate member302is capable of moving within a lumen of the first elongate member304. Accordingly, the second elongate member302can have a diameter that is less than a diameter of the first elongate member304such that it can telescope in and out of the first elongate member304. Like the first elongate member304, the second elongate member302comprises one or more pull or articulating wires to articulate the second elongate member304through tortuous anatomy. In some embodiments, the first elongate member304and the second elongate member302each share an equal number of pull or articulating wires. In other embodiments, the first elongate member304and the second elongate member302each have a different number of pull or articulating wires. For example, the first elongate member304can have a greater number of pull wires (e.g., up to four) than the second elongate member302(e.g., up to two). This advantageously allows the second elongate member302to have a lesser diameter such that it can navigate even smaller tortuous vessels than the first elongate member304. As shown inFIG.24, a hub306can be coupled to one or more of the first elongate member304and second elongate member302. The hub306comprises one or more lines308for performing suction or irrigation via the first and/or second elongate members304,302. In some embodiments, the one or more lines308can be attached to a pump for providing suction capabilities by the first and/or second elongate members304,302. FIG.25illustrates an alternative embodiment of an instrument system300for performing clot removal. The instrument system300is similar to the system inFIG.24in that it includes a distal instrument handle274coupled to a first elongate instrument (e.g., an access sheath304) and a proximal instrument handle272coupled to a second elongate instrument (e.g., a clot removal catheter302that travels through the access sheath304). In the present embodiment, however, the instrument system300further comprises one or more anti-buckling devices276positioned adjacent the instrument handles274,272. The anti-buckling devices276advantageously reduce the risk of buckling that can occur as an elongate member is fed through a patient. In some embodiments, one or more of the anti-buckling devices276can be replaced with a feed roller that helps to feed an elongate member into the patient. In some embodiments, the anti-buckling devices276advantageously provide for stabilization of the instrument system300upon insertion into an incision (e.g., via the femur or radially). FIG.26illustrates a catheter instrument300for performing clot removal.FIG.27illustrates a different front perspective view of the catheter instrument300ofFIG.26. The catheter instrument300comprises a plurality of elongate members including an access sheath304, a clot removal catheter302, and a clot disruptor312. A guide wire, which can be guided through the clot disruptor312, is not shown. In some embodiments, each of these elongate members is controlled robotically. In some embodiments, only some of the elongate members is controlled robotically, while others can be controlled manually. For example, in some embodiments, the access sheath304and the clot removal catheter302can be robotically and telescopically controller, while the clot disruptor312and the guide wire can controlled manually. In other embodiments, only the guide wire can be delivered robotically, while the access sheath304, clot removal catheter302, and clot disruptor312can be delivered manually thereover. The access sheath304comprises an elongate member that is capable of insertion through a femoral artery. The access sheath304is configured to serve as a conduit for one or more elongate members that are received therein, including the clot removal catheter302and the clot disruptor312. The access sheath304comprises a flexible shaft or tube that can be formed at least in part by a braided structure. In some embodiments, the access sheath304comprises nylon with a stainless steel braid. The access sheath304is advantageously capable of having both structure and flexibility to maneuver through different vessels of a patient. The clot removal catheter302comprises an elongate member that is capable of telescoping through the access sheath304. In some embodiments, the clot removal catheter302comprises an aspiration catheter for aspirating and suctioning a clot therein. In some embodiments, the clot removal catheter302can be coupled to a stent, net, basket, or other 3-D structure (shown inFIG.29A) that is capable of physically capturing a clot therein for removal. In some embodiments, rather than serving as a clot remover, the catheter302can be used to administer thrombolytics (e.g., streptokinase, urokinase, tPA) and/or other anticoagulants to help break down clots via drug administration. In other words, one or the objectives of the clot removal catheter302is to provide reperfusion of an affected vessel by mechanical thrombectomy, administration of thrombolytics, or any combination thereof. Like the access sheath304, the clot removal catheter302advantageously has both structure and flexibility to maneuver through different vessels of a patient. In some embodiments, the clot removal catheter302can also be formed in part of polymer that is coupled to a stainless steel braid. In embodiments in which the clot removal catheter302is an aspiration catheter, the clot removal catheter302can be coupled to an aspiration pump (not shown). The pump can be coupled to a flow meter to control the amount of pressure provided to the clot removal catheter302. In some embodiments, the clot removal catheter302can be controlled to a feedback loop in a processor (e.g.,240inFIG.21) that constantly monitors and maintains an appropriate pressure in the clot removal catheter302. In addition, such a processor240can be used to determine whether the clot removal catheter302should be used for one function (e.g., aspiration) or another (e.g., irrigation). The clot disruptor312comprises an elongate member that is capable of maneuvering through the lumens of the clot removal catheter302and access sheath304. The clot disruptor312can be used to modify a clot to make it easier for removal by the clot removal catheter302. For example, in some embodiments, the clot disruptor312comprises a shaft that is capable of piercing through a clot. The shaft can be coupled to an optional disruptor or cutter312(e.g., a dull blade or propeller). The shaft is capable of rotation such that the clot can be modified or disrupted, thereby reducing the clot to smaller particles. In some cases, this can make a clot easier to be removed by the clot removal catheter302. In some embodiments, the clot disruptor312can be formed of stainless steel or nitinol. The clot disruptor312can have a blunt distal tip so as to pass through a clot with minimal risk of harm to a patient's vessel, thereby advantageously reducing the risk of inadvertent vessel scraping. A guidewire (not shown inFIG.26) capable of insertion into a patient's vasculature can also be part of the instrument300. The guidewire can be inserted either manually or robotically, with one or more of the access sheath304, clot removal catheter302, and/or the clot disruptor312being delivered thereover. In some embodiments, the guidewire can be formed of a thin, flexible biocompatible material, such as stainless steel or nitinol, and can serve as a guide to target clot of the patient. FIG.28illustrates a cross-sectional view of an elongate member of the catheter instrument300ofFIG.26. The cross-sectional view can be representative, for example, of a cross-section of the access sheath304. From this view, one can see how the elongate member comprises a working lumen or channel340for guiding one or more catheters or instruments therethrough. While in the present embodiment, the working channel340is illustrated as having a singular circular cross-section, in other embodiments, the working channel340can have a cross-section that is oval in shape. In some embodiments, the working channel340can be of a dual connecting oval with a narrower width between them. The elongate member comprises one or more drive or articulating cables or wires322. In the present embodiment, the elongate member comprises four articulating wires322that are distributed about a circumference of the elongate member. In some embodiments, the four articulating wires322are distributed approximately 90 degrees from one another. The articulating wires322can be received within coil pipes320. While in the present embodiment, the elongate member includes four articulating wires322, in other embodiments, the elongate member can include less than four articulating wires322, such as three, two, one or none at all. By minimizing the number of articulating wires322, this can be particularly helpful for maintaining a smaller diameter for elongate members that are used to navigate smaller vessels (e.g., in the cerebrovasculature). Accordingly, one skilled in the art will appreciate that the cross-sectional view of the elongate member inFIG.28is representative of one possible embodiment, and that other embodiments may include a different number of articulating wires322. The elongate member further comprises a pair of sensors345. In some embodiments, the sensors345can comprise EM sensors that can be used, for example, to detect and measure roll of the elongate member. In some embodiments, one or more of the elongate members can include a sensor that can be used to identify concentricity within a vessel during navigation (e.g., via ultrasound), as discussed below with respect toFIG.33B. In some embodiments, in addition to or in place of the sensors345, the elongate member can comprise one or more shape sensing fibers. The shape sensing fibers can be used to provide localization information for an elongate member as it travels through the patient's vasculature. In the present embodiment, the elongate member comprises a spine321that serves as a backbone for the elongate member. In some embodiments, the spine can be formed of a biocompatible material such as nitinol. In some embodiments, the elongate member comprises one or more braided features that extend along a length of the elongate member. FIG.29Aillustrates an alternative embodiment of a catheter instrument300for performing clot removal including an inflation member305. The catheter instrument300is similar to the catheter instrument shown inFIG.26in that it includes an access sheath304, a clot removal catheter302and a clot disruptor312. In the present embodiment, however, the catheter instrument300includes additional features, including an inflatable member305for vessel occlusion, a 3-D structure316for clot retrieval, and a clot cutter314. In the illustrated embodiment, the catheter instrument300comprises an inflatable member305that is coupled to the outer body of the access sheath304. The inflatable member305is capable of inflation to thereby occlude a vessel. The advantage of the inflatable member305is that it can stabilize the catheter instrument300within a patient's vasculature, such that it allows for one or more elongate members to be delivered accurately and with precision. In some embodiments, the inflatable member305comprises a balloon that can be expanded to occlude a vessel. In the illustrated embodiment, the catheter instrument300further comprises a 3-D structure316, such as a stent, net, basket, or retriever that is used to capture a clot. In some embodiments, the 3-D structure316is coupled to the clot removal catheter302, and can be deployed via a physician. In other embodiments, the 3-D structure316is coupled to the clot disruptor312and can be deployed as the clot disruptor312is moved far enough out of the clot removal catheter302. In the illustrated embodiment, the catheter instrument300further comprises a clot modifier or disruptor312that includes a clot manipulator in the form of a propeller or cutter314. The cutter314can help to disrupt a clot and to turn it into smaller particles if desired. In some embodiments, the clot disruptor312is capable of rotation, thereby causing disruption of the clot structure. FIG.29Billustrates an alternative embodiment of a catheter instrument300for performing clot removal including a distal protector313. The catheter instrument300is similar to the catheter instrument inFIG.26in that it includes an access sheath304, a clot removal catheter302and a clot disruptor312. In the present embodiment, however, the clot disruptor312is coupled to a multi-functional distal guard313. The distal guard313can serve multiple functions. First, it can be used to protect clot material from being distributed downstream from the catheter instrument300. This advantageously helps prevent loosened clot material from flowing beyond the distal guard313, thereby reducing the risk of subsequent strokes from occurring. Second, the distal guard313can be used to retrieve the clot back towards the clot removal catheter302. This can help, for example, in the event that a clot is positioned too far from aspiration by the clot removal catheter302. In this event, the clot disruptor312can be used to pierce a clot, whereby the distal guard313can be deployed or inflated beyond the clot. As the clot disruptor312is retracted through the clot removal catheter302, the distal guard313helps to physical move any clot material back towards the clot removal catheter302. One skilled in the art will appreciate that the distal guard313can be attached to any of the instruments described within this application, and is not limited to the embodiment ofFIG.29B. FIG.29Cillustrates an alternative embodiment of a catheter instrument300for performing clot removal including a dual lumen catheter. The catheter instrument300is similar to the catheter instrument inFIG.26in that it includes an access sheath304, a clot removal catheter302and a clot disruptor312. The catheter instrument300also includes a distal guard303coupled to the clot removal catheter302, as described with respect toFIG.29B. In the present embodiment, however, the clot removal catheter302is in the form of a dual-lumen comprised of a first lumen307of a first diameter and a second lumen309of a second diameter separated by a valve315. By providing these different lumens307,309, the aspiration capabilities of the clot removal catheter302can be modified, and in some cases, enhanced relative to a single lumen catheter. In some embodiments, the clot removal catheter302can be viewed as having a tapered tip separated by a wider proximal lumen. The catheter instruments300described herein can be used with any of the systems described above. As noted above, in some embodiments, each of the elongate members of the instruments300can be robotically controlled, while in other embodiments, some of the elongate members can be robotically controlled while some of the elongate members can be manually controlled. C. Navigation and Imaging Systems for Clot Removal. Below are various imaging and navigation systems that can accompany any of the systems and instruments described above. Advantageously, many of these imaging and navigation systems can be used not only with robotically-controlled instruments (such as those described above), but can also be used to better guide and navigate non-robotically controlled (e.g., manual) instruments through tortuous vessels. Improved imaging systems and methods can be provided to assist in the navigation of one or more clot removal instruments. The imaging systems can take images both pre-procedurally and during a procedure to help aid in the navigation of a clot removal instrument. FIG.30Aillustrates a 3-D model380that can be generated using pre-operational or pre-procedure images.FIG.30Billustrates an example pre-operational image385that can be used to generate a 3-D model. Pre-procedural imaging can be done by one or more of computerized tomography (CT), CT angiography (CTA), magnetic resonance angiography (MRA), or fluoroscopy. In an embodiment that uses multiple pre-procedural imaging approaches, a physician can switch the source of his/her navigation from one imaging approach to another (e.g., switch between CT-based navigation to CTA-based navigation). In another embodiment, navigation software can combine pre-procedural image data from multiple approaches to improve the quality and amount of information that is displayed to a clinician or physician. This can include creating a manipulatable 3-D reconstruction of vasculature from the images. InFIG.30A, a 3-D model or reconstruction380of vasculature that has been generated from one or more imaging scans (e.g., fluoroscopy, CT, CTA, or MRA), such as the image385shown inFIG.30B. Once a 3-D reconstruction380of vasculature has been created, a clinician or physician can utilize the 3-D reconstruction380to navigate through tortuous vessels leading up to and through the cerebrovasculature. In some embodiments, an occlusion site (e.g., location of a clot) can be identified on the 3-D model or reconstruction of the vasculature. In some embodiments, the occlusion site can be optionally identified via software and added to the 3-D model. In some embodiments, identification of the occlusion site is performed by a physician in a pre-procedural planning step. In other embodiments, identification of the occlusion site is performed automatically by software with little or no help from the physician. As it is crucial to identify an occlusion site, particularly during an acute ischemic stroke, there can be significant value in using software to automate the location of an occlusion site. The 3-D model (such as the model380shown inFIG.30A), which can include an optional occlusion site, can be available for viewing on a screen by a clinician or physician. For example, the 3-D model can be viewed on a screen210of a console220as shown, for example, inFIG.21. In addition to the 3-D model380shown inFIG.30A, additional virtual models can be generated and displayed on the same or different screen of a console, such as those shown inFIGS.31and32. FIG.31illustrates a first-person view410of a generated model of a vessel415. The generated model can be constructed using any of the imaging modalities described above, and includes a model of a vessel415viewed from a first-person. From this view, a physician can navigate a clot removal instrument from a current location to an occlusion site. From this first-person view410, one can see a virtual, generated model of a catheter400as it is being driven into a virtual, generated model of vessel415. An optional ring indicator that includes a right marker417and a left marker419of different colors can be provided. The optional right and left markers417,419advantageously assist a clinician or physician that is controlling the instrument (e.g., via a controller or pendant) to know which way to steer and/or navigate the instrument within the vessel. FIG.32illustrates a third-person view420of a generated model of a vessel. The generated model can be constructed using any of the imaging modalities described above, and includes a model of a vessel415viewed from a third-person. From this view, a physician can navigate a clot removal instrument from a current location to an occlusion site. The third-person view420shows a virtual, generated model of a catheter400as it is being driven into a virtual, generated model of vessel415. The ring indicator including the right marker417and left marker419is also shown herein. Advantageously, a clinician or physician can switch between any of the different views, such as the first-person view410and third-person view420. In some embodiments, a picture-in-picture view can be displayed on a viewing screen in which a first-person view410is provided within a third-person view420, or vice versa. Other possible views that can be generated besides a first-person view and a third-person view include zoomed-out and isometric views, all of which may be helpful at various points in a procedure. A clinician or physician can use one or more of the generated models described above to navigate an instrument through a vessel to manipulate or remove a clot. Following initial access (e.g., through an incision), a physician can navigate and follow a predetermined path to a site of occlusion using pre-procedural and intra-procedural imaging. Live navigation data can be provided to the physician during a procedure to better navigate a tortuous path of the vessels. The live navigation data can be used to create a view or display as shown inFIGS.31and32. Before and during navigation, data can be collected to generate a “navigation model” and a “localization model.” A navigation model is a collection of data that can be used to guide a physician to a site of occlusion. This model can include position coordinates of an occlusion, or a complex 3-D reconstruction of vascular anatomy, blood flow rates, occlusion size and composition, and optimal path to access an occlusion site. A localization model is a collection of data that can be used to determine the location of an instrument within a vessel. This model can be generated using information gathered from, for example, various sensors (e.g., EM or ultrasound) and/or shape sensing technology. The images shown above, including the 3-D reconstruction inFIG.30A, the first person view inFIG.31and the third person view inFIG.32, can all be considered navigation models available to a clinician or physician. Such navigation models can be available to a physician during a clot removal procedure. During such a procedure, intra-procedure localization data can be collected. This localization data can be collected via electromagnetic sensing, shape-sensing technology, or image analysis based of fluoroscopic images. In embodiments involving robotic control, motor output and position, force, and torque sensing may also be inputs to the localization system. Once localization of an instrument within a vessel has been established, the collected localization information may be reconciled with pre-procedural images. In some embodiments, the reconciliation is performed using a registration step. In some embodiments, registration can involve moving an instrument to one or more predetermined positions on/in a patient, or placing electromagnetic patches on specific parts of a patient. In some embodiments, data from CT and fluoroscopic imaging can be collected both prior to and during a procedure, and intra-procedure images can be registered to pre-procedure images. In some embodiments, intra-procedure imaging can be used to improve the navigation model. For example, in some embodiments, intra-procedure imaging techniques can include fluoroscopy or intravascular ultrasound (IVUS). In some embodiments, IVUS in particular may enable concentric viewing a vascular lumen, thereby enabling a first person endoluminal camera view. FIG.33Aillustrates two side-by-side concentric views generated by IVUS to assist in navigation. The first concentric view450on the left shows a concentric image of a vessel to be navigated. The second concentric view450on the right shows the same concentric image of a vessel, but with an optional virtual image overlay460positioned thereover. The optional virtual image overlay460advantageously identifies areas of stenosis and plaque that can be useful to a clinician or physician that is navigating through a vessel. Such an overlay460may better an enable an operator to navigate tortuous sections of vasculature to avoid regions of stenosis on the vessel walls. FIG.33Billustrates a generated model accompanied by an indicator431for catheter concentricity within a vessel. In this embodiment, a third person view430of a model vessel415(e.g., generated from any of the pre-procedural or intra-procedural imaging techniques described above) including a catheter instrument300for clot removal is shown therein. The catheter instrument300comprises the access sheath304, clot removal catheter302(e.g., aspiration catheter), and clot disruptor312. A virtual indicator overlay431overlays the third person view430. The indicator431shows a representation of a vessel wall432and a representation of a tip of the catheter instrument434. In some embodiments, the indicator431can be generated via one or more sensors positioned on or within the catheter instrument, as described above. Advantageously, the indicator431helps a clinician or physician to ensure that the driven catheter instrument300is concentric within a vessel415, thereby reducing the risk of inadvertent vessel scraping and intra-operative strokes. While in the present embodiment, a virtual indicator431is overlay on top of a generated third person view of a vessel, in other embodiments, a virtual indicator431is overlay on top of a live or camera image of a vessel. D. Methods for Clot Removal. The systems and devices described above can be used to modify and remove clots. Below are some exemplary methods for performing clot modification and removal. These methods can be performed after performing pre-operational and/or intra-operational imaging on a patient's vasculature. As discussed above, in some embodiments, a virtual model or representation of the patient's vasculature can be generated based on the pre-operational and/or intra-operational imaging. The virtual model of the vasculature can then be displayed on a viewing screen for a physician. Upon registration of a catheter instrument for clot removal, a virtual model or representation of the catheter instrument can then be displayed on the virtual model of the vasculature. A clinician or physician can then use a controller (e.g., pendant, gimbal, or joystick) of a robotic system to drive the catheter instrument through the vasculature, using any of the steps or sequences described below. FIGS.34-36illustrate a sequence of steps for clot modification and removal. In the present embodiment, a catheter instrument300including a clot removal catheter302in the form of an aspiration catheter is provided to suction and remove a clot. In other embodiments, the clot removal catheter302can deploy a 3-D structure such as a stent, net, basket or retriever to assist with clot removal. In some embodiments, the clot removal instrument302can both aspirate and deploy a 3-D structure. FIG.34illustrates the delivery of a catheter instrument300to a position near a clot390. The catheter instrument300comprises an access sheath304, a clot removal catheter302, a clot disruptor312, and a guidewire318. In some embodiments, the guidewire318(which is optional) can be delivered first through a vessel (e.g., via a femoral or radial incision) to a location adjacent the clot390. The guidewire318can be delivered manually and/or robotically to a desired location. In other embodiments, other elongate members, such as the access sheath304, can be delivered first through an incision, and the guidewire318can be delivered thereafter. In the present embodiment, an access sheath304can be inserted into a patient, either before or after insertion of the guidewire318. The access sheath304can be navigated and parked anywhere in the vasculature of a patient, such as at or near the carotid artery. In some embodiments, an inflatable member (e.g., balloon)305of the access sheath304can be deployed to assist in the stabilization of the access sheath304within a vessel5. The access sheath304can be delivered manually and/or robotically to a desired location. The access sheath304can move in tandem and/or independently with the clot removal catheter302. The clot removal catheter302can be delivered through a lumen of the access sheath304and over the guidewire318. In some embodiments, the clot removal catheter302can move in a telescoping fashion relative to the access sheath304. While in the present embodiment, the clot removal catheter302comprises an aspiration catheter, in other embodiments, the clot removal catheter302can comprise a deployable 3-D structure (e.g., stent, net or basket), or a combination of an aspirator and deployable 3-D structure for clot capture. The clot removal catheter302can be delivered manually and/or robotically to a desired location. Advantageously, the clot removal catheter302can be of a smaller diameter than the access sheath304, such that it can navigate even smaller vessels (e.g., beyond the carotid artery). Accordingly, in some embodiments, the clot removal catheter302can be positioned more distal than the access sheath304and closer to the clot390in some embodiments. With the access sheath304and clot removal catheter302in place, a clot disruptor312can be inserted therethrough. Like the guidewire318, the clot disruptor312is optional. In some embodiments, the clot disruptor312comprises an elongate member that is capable of modifying the size and shape of the clot390. InFIG.34, the access sheath304, clot removal catheter302, clot disruptor312, and guidewire318have been navigated through a vessel5to a location adjacent the clot390. FIG.35illustrates the catheter instrument300ofFIG.34suctioning the clot390. At this time, the clot disruptor312, including the optional guide wire314therein, have pierced the clot390. The clot removal catheter302has been positioned adjacent the clot390such that it is capable of suctioning the clot390. A vacuum pump can be turned on, thereby generating suction energy in the clot removal catheter302to suction the clot390. FIG.36illustrates the catheter instrument300ofFIG.34being retracted from a vessel5after suctioning the clot390. At this time, the clot390has been suctioned by the clot removal catheter302, and the entire catheter instrument300is being retracted through the vasculature of the patient. FIGS.37-39illustrate an alternative sequence of steps for clot modification and removal using a catheter instrument300that is different from that shown inFIGS.34-36. In the present embodiment, a catheter instrument300such as shown inFIG.29Bis used for clot removal. FIG.37illustrates the delivery of a catheter instrument300to a position near a clot390. The catheter instrument300comprises an access sheath304, a clot removal catheter302, and a clot disruptor312. In some embodiments, an optional guidewire (not shown) can be delivered first through a vessel (e.g., via a femoral or radial incision) to a location adjacent the clot390. The guidewire can be delivered manually and/or robotically to a desired location. In other embodiments, other elongate members, such as the access sheath304, can be delivered first through an incision, and the guidewire can be delivered thereafter. In the present embodiment, an access sheath304can be inserted into a patient, either before or after insertion of the guidewire. The access sheath304can be navigated and parked anywhere in the vasculature of a patient, such as at or near the carotid artery. The access sheath304can be delivered manually and/or robotically to a desired location. The access sheath304can move in tandem and/or independently with the clot removal catheter302. The clot removal catheter302can be delivered through a lumen of the access sheath304and over the guidewire318. In some embodiments, the clot removal catheter302can move in a telescoping fashion relative to the access sheath304. While in the present embodiment, the clot removal catheter302comprises an aspiration catheter, in other embodiments, the clot removal catheter302can comprise a deployable 3-D structure (e.g., stent, net or basket), or a combination of an aspirator and deployable 3-D structure for clot capture. The clot removal catheter302can be delivered manually and/or robotically to a desired location. Advantageously, the clot removal catheter302can be of a smaller diameter than the access sheath304, such that it can navigate even smaller vessels (e.g., beyond the carotid artery). Accordingly, in some embodiments, the clot removal catheter302can be positioned more distal than the access sheath304and closer to the clot390in some embodiments. With the access sheath304and clot removal catheter302in place, a clot disruptor312can be inserted therethrough. In some embodiments, the clot disruptor312comprises an elongate member that is capable of modifying the size and shape of the clot390. In the present embodiment, the clot disruptor312comprises a multi-functional distal guard313(shown inFIGS.38and39) that has yet to be deployed. FIG.38illustrates the catheter instrument300ofFIG.37after deploying a distal guard313in a position distal of the clot390. At this time, the clot disruptor312has pierced the clot390. A distal guard313has been deployed along the clot disruptor312in a distal location from the clot390. The distal guard313advantageously serves to block embolic material from the clot390that may inadvertently drift into the vessel5, thereby reducing the risk of a downstream stroke. Advantageously, the distal guard313can work in conjunction with the aspirator of the clot removal catheter302to remove the clot390. As shown inFIG.39, the distal guard313is multi-functional in that it also helps to physically retract and remove the clot390from the vasculature. Advantageously, either before, during or after the clot disruptor312has pierced the clot390, the vacuum pump can be turned on to provide for aspiration from the clot removal catheter302. For example, advantageously, in some embodiments, the suctioning capabilities of the clot removal catheter302can be turned on during the piercing of the clot390by the clot disruptor312so that it can help to prevent movement of the clot390while it is being pierced. This is beneficial as any contact with the clot390(e.g., via the clot disruptor312) can cause the clot390and smaller particles of the clot to drift to undesirable locations. As such, applying suction from the clot removal catheter302before, during, or after piercing of the clot can provide a number of advantages. FIG.39illustrates the catheter instrument300ofFIG.37being retracted from a vessel5after capturing the clot390in the distal guard313. As the catheter instrument300is retracted, the distal guard313physically retracts the clot390from the vessel5. In some embodiments, during the retraction, the clot removal catheter302is also in the process of aspiration. By providing aspiration, this advantageously reduces the risk of the clot390drifting inadvertently into adjacent vessels of the patient, thereby reducing the risk of downstream strokes. WhileFIGS.34-36and37-39illustrate sequences of particular methods of clot removal, one skilled in the art will appreciate that the sequences are exemplary, and that the systems and methods described herein are not limited to such procedures. FIG.40is a flowchart illustrating an example method4000for clot removal. The method4000can be implemented in certain robotic systems, such as the robotic systems illustrated inFIGS.1-15and21and others. In some implementations, one or more computer devices may be configured to execute the method4000. The computer devices may be embodied by one or more processors (such as that represented by240inFIG.21) that can be used to execute the method4000. The computer-readable memory may store instructions that may be executed by the processor(s) to perform the method4000. The instructions may include one or more software modules as described more below. By way of example and not limitation, the computer devices may be in the tower30shown inFIG.1, the cart shown inFIGS.1-4,21, and42, the beds shown inFIGS.5-10,21, and41-43, etc. As described previously, certain parts of the robotically controlled instrument system300may be robotically or manually controlled. The method4000begins at block4001, at which a robotically controlled instrument system300is driven toward a clot390within vasculature5of a patient. The robotically controlled system300may include at least the first elongate member304and the second elongate member302positioned coaxially with the first elongate member304. The robotically controlled instrument system300may include additional elongate members and other features, as described previously. The first elongate member304may be an access sheath and the second elongate member302may be a clot removing (e.g., aspiration) catheter. At block4003, the method4000involves applying a pump of the second elongate member302to aspirate the clot390. As described previously, a vacuum pump can be turned on, thereby generating suction energy in the clot removal catheter302to suction the clot390. E. Software. Various aspects of the systems, devices and methods described above can be robotically controlled. Advantageously, one or more processors (such as that represented by240inFIG.21) can be used to assist in the imaging, driving and navigation of the systems and devices described above. In related aspects, the one or more processors may be implemented as any of a variety of suitable circuitry, such as one or more microprocessors, application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), discrete logic, software, hardware, firmware or any combination thereof. When the techniques are implemented partially in software, a device may store instructions for the software in a suitable, non-transitory computer-readable medium and execute the instructions in hardware using one or more processors to perform the techniques of this disclosure. In some embodiments, one or more processors can be used to prioritize cases of complex or multi-vessel occlusion. This can be important, for example, in the event that there multiple sites of occlusion due to multiple clots. In some embodiments, the processors can be used to identify sites of lesser perfusion due to clotting using pre-operational images, such as CT and CTA. In other embodiments, in addition to using pre-operational images, one or more processors can be used to prioritize cases of complex or multi-vessel occlusion based on information related to clot size, flow or perfusion, and blockage location. Such sites of lesser perfusion can be identified to a physician, who can then prioritize treatment. In some embodiments, upon identifying a site of lesser perfusion, a physician can manually move a clot removing instrument from one location to another to address the site of lesser perfusion. In other embodiments, a clot removing instrument can be automatically moved from one location to another, with little to no input from a physician. In some embodiments, one or more processors can also assist in navigation. As noted above, a navigation model can be provided that includes a virtual representation of relevant vasculature. Image processing and computer vision algorithms can be used to identify the site of an occlusion, quantify the size and severity of the blockage, and evaluate perfusion. In some embodiments, a path can be generated anywhere along an access site (e.g., femoral or radial) to the site of the occlusion, either before or during a procedure. The path can be generated on a viewing screen for a clinician or physician. Advantageously, as a physician drives a catheter instrument including a clot removal catheter towards the clot, the location of the catheter instrument along the path can be updated. The location can be updated with the help of various types of technology, including EM and ultrasound sensors, as well as fiber optic shape sensing technology. In some embodiments, the processor can be regularly updated with localization information until a surgeon completes a clot removing procedure. In some embodiments, the path that the catheter instrument took can be recorded and stored on a computer-readable medium. In some embodiments, this information can help a catheter instrument to be more easily retracted from the vasculature. 3. Implementing Systems and Terminology. Implementations disclosed herein provide systems, devices and methods for the modification and removal of clots. One skilled in the art will appreciate that any of the systems described above can be used to drive any of the instruments to perform any of the methods described above. It should be noted that the terms “couple,” “coupling,” “coupled” or other variations of the word couple as used herein may indicate either an indirect connection or a direct connection. For example, if a first component is “coupled” to a second component, the first component may be either indirectly connected to the second component via another component or directly connected to the second component. Any parameters related to robotic motion, imaging and navigation, and task prioritization as described above, may be stored as one or more instructions on a processor-readable or computer-readable medium. The term “computer-readable medium” refers to any available medium that can be accessed by a computer or processor. By way of example, and not limitation, such a medium may comprise random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory, compact disc read-only memory (CD-ROM) or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer. It should be noted that a computer-readable medium may be tangible and non-transitory. As used herein, the term “code” may refer to software, instructions, code or data that is/are executable by a computing device or processor. The methods disclosed herein comprise one or more steps or actions for achieving the described method. The method steps and/or actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is required for proper operation of the method that is being described, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims. As used herein, the term “plurality” denotes two or more. For example, a plurality of components indicates two or more components. The term “determining” encompasses a wide variety of actions and, therefore, “determining” can include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, a database or another data structure), ascertaining and the like. Also, “determining” can include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory) and the like. Also, “determining” can include resolving, selecting, choosing, establishing and the like. The phrase “based on” does not mean “based only on,” unless expressly specified otherwise. In other words, the phrase “based on” describes both “based only on” and “based at least on.” The previous description of the disclosed implementations is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these implementations will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other implementations without departing from the scope of the invention. For example, it will be appreciated that one of ordinary skill in the art will be able to employ a number corresponding alternative and equivalent structural details, such as equivalent ways of fastening, mounting, coupling, or engaging tool components, equivalent mechanisms for producing particular actuation motions, and equivalent mechanisms for delivering electrical energy. Thus, the present invention is not intended to be limited to the implementations shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

11857278

With reference to the figures,FIG.1shows in schematic form a robotized surgery system, denoted generally by10, provided according to the invention. The system10comprises at least one robot arm11which acts under the control of a control console12managed by the surgeon who is for example sat in a comfortable working position. The console may also be mounted on wheels so that it can be easily displaced. The robot arm will be of the substantially known type suitable for the specific use. In the system10shown here the robot arms are three in number, although a different number may be easily used. The robot arm (or each robot arm) terminates in a wrist piece which is able to support and operate a surgical instrument for use on a patient13. This instrument will usually be a known instrument for endoscopic, and in particular laparoscopic, operations. One of the instruments is advantageously a telecamera14which records the operating field (in this particular case, the patient's interior), while the other instruments may be suitable known surgical tools15,16(forceps, aspirators, scalpels, etc.). The robot arms, the instruments and the actuators for manoeuvring these instruments will not be described and illustrated further here, since they are known and may be easily imagined by the person skilled in the art. The surgical operations which are possible with the system and the methods for performing them are also not further described here, since they may be easily imagined by the person skilled in the art. The robot arms are operated by a suitable known electronic control unit30so as to perform the movements entered via the console12. The unit30will receive the high-level movement commands (for example, desired position and inclination of the tool supported by the robot) and will execute them, converting them into the corresponding sequences of signals to be sent to the individual motors of the robot arm articulations. The robot arms may also be provided with known force sensors, used both by the unit30to prevent damage due to collision of the arm with objects in the working space, and in order to provide suitable feedback to the operator at the console, as will be clarified below. The connections between the console and the unit for controlling the robots may be advantageously of the optical fibre type, in order to reduce the possibility of interference with the signals transmitted. Suitable robot arms and control systems are, for example, described in WO2007/088208, WO2008/049898 and WO2007/088206. In order to perform the movements of the surgical instruments, the console may advantageously comprise a pair of known manipulators17,18which can be gripped by the surgeon and the movements of which are suitably reproduced by the surgical instruments by means of movement of the robot arms11. Advantageously, the manipulators may be of the known “reactive” type (i.e. with a tactile interface which provides a weighted movement and tactile sensing) such that the surgeon is also able to feel on the manipulators the forces exerted by the robotized surgical instruments on the patient's tissues. Suitable tactile interfaces are well-known in the sector of robotized endoscopic surgery. Usually, each manipulator will operate a robot arm. Advantageously, in the case of more than two arms, a control will be provided on the console so as to be able to assign, as required, each manipulator to a desired robot arm, as will be explained further below. A keyboard19and other command input devices, for example also comprising a pedal device20, may also be envisaged. The device20may comprise one or more pedals for activating, for example, the supply of power for monopolar and bipolar instruments, the irrigation and aspiration functions, if envisaged for a specific instrument, etc. The console12also comprises an eye movement tracking system21or so-called “eye tracker” for detecting the direction of the surgeon's gaze towards the console and for controlling the surgical system also depending on the gaze directions detected. In this way, the surgeon may control functions of the system by means of movement of the eyes. Advantageously, the console comprises a video screen22with at least one zone23for showing a view of the operating field. This view is provided by the telecamera14which may be supplemented (for example so as to provide the surgeon with additional information and/or improve his/her understanding of the operating field) with artificial pictures generated by a computerized system24, known per se, for managing the console, which will be further described below. As will become clear below, the computerized system24generates and manages a human machine interface (HMI) which allows the surgeon to interact with the surgical system. For conventional two-dimensional viewing, the picture supplied by the endoscope may be directly viewed on the screen22. Advantageously, however, a three-dimensional system for viewing the operating field may be envisaged. In this case, the telecamera14may be of a known stereoscopic type which provides suitable signals25,26representing two different “right-hand” and “left-hand” pictures which are recorded spatially offset. The signals25,26are processed by an electronic device27so that the 3D picture may be shown to the surgeon by means of a stereoscopic viewing system. From among the various known stereoscopic viewing systems a polarized filter system has been found to be particularly advantageous; in this system the electronic device27comprises a known stereo mixer which alternates lines of the right-hand and left-hand pictures received from the telecamera so as to display them interlaced in the viewing area23of the screen. Alternate odd and even horizontal lines of the picture on the screen thus represent alternately lines of the right-hand and left-hand pictures recorded by the telecamera. A known filter provided with two different polarization modes for the even interlaced lines and the odd interlaced lines is provided in the area23for viewing this interlaced picture. In order to view the picture, the surgeon wears glasses28with the two lenses polarized in a manner corresponding to the two polarization modes of the filter on the screen, so as to direct towards the right eye only the lines of the picture belonging to the original right-hand picture recorded by the telecamera, while the left-hand eye receives only the lines of the picture belonging to the original left-hand picture recorded by the telecamera. It is thus possible to show the surgeon the desired 3D picture of the operating field. If desired, using a similar procedure, artificial stereoscopic pictures produced by the computerized system24may also be shown in 3D form. In any case, by means of the tracking system21it is possible to detect the direction of the surgeon's gaze towards the screen22and define which zone of the screen he/she is looking at or not looking at. Using a 3D viewing system with polarized glasses there is no interference with the tracking system. Moreover, glasses with polarized lenses for 3D viewing can be easily designed so as to be compatible with the normal eyeglasses. It has been found to be particularly advantageous for the tracking system to send a command which disables the movement of the robot arms when a direction of the gaze which falls outside of the screen, or at least outside of the screen zone which reproduces the operating field, is detected. SeeFIG.4C. In this way, a safety system preventing movements of the arms without direct supervision of the surgeon is provided. A so-called “dead man's” function is thus obtained for activating the robot and keeping it activated while the user is looking at the screen. Advantageously, for additional safety, a further control means may be provided (for example a pushbutton31on a handgrip or a pedal device20) where it is required to give a dual consent for enabling the movement commands so that, in order to reactivate the movement, the surgeon must look at the picture on the screen and also give a manual consent command, while the movement may be interrupted by simply looking away from the picture. Advantageously, the screen22shows, in addition to the view from the endoscope, also at least part of the human machine interface. The computerized system24which provides the interface shows on a screen selection areas29associated with system commands. Advantageously, the selection areas may be arranged on the same screen22which shows the view of the operating field. For example, these selection areas may be arranged in the bottom part of the screen, underneath the area23for viewing the operating field. The tracking system estimates the direction of the surgeon's gaze and performs selection of the commands associated with a selection area when it detects a gaze direction which falls within this area. The commands associated with the various selection areas may be of any type considered to be useful. For example, these commands may be chosen from among those which are frequently used when performing a robotized surgery operation. It has been found to be particularly advantageous (in particular when the console comprises two operating manipulators and more than two robot arms) if the commands associated with the selection areas comprise the commands for assigning the manipulators to the robot arms. The surgeon may thus alternate control of the various robot arms on the two manipulators, without letting go of the manipulators, but instead simply looking at the corresponding selection areas. For example, the surgeon may temporarily switch over to control of the arm with the telecamera, in order to modify the view of the operating field, and then rapidly return to control of the robot arm with which he/she was operating. For additional safety, the console may advantageously comprise a device for inputting a special command confirming execution of the command associated with the selection area looked at. This device may advantageously be a pushbutton31which is arranged on one or both the manipulators, so as to be pressed, for example, using the thumb of the hand gripping the manipulator. It is thus possible to confirm easily the actions activated by the eyes via the eye tracking system, for example in order to select a robot to be associated with the manipulator, open/close the surgical instruments and modify the settings of the robot which is being operated. Another use of the pushbutton may also be that of controlling the degree of freedom of a twisting movement on the instrument (if available). It is also possible to envisage advantageously that the procedure for assigning a robot may be performed by visually selecting the picture of the new robot which is to be assigned, confirming the selection by means of the pushbutton and then dragging the picture selected into the position where the picture of the robot currently assigned to the right-hand grip or left-hand grip is shown. Dragging is performed by keeping the pushbutton pressed and directing one's gaze towards the robot position. In order to end the dragging operation, the pushbutton must be released while keeping one's gaze focused on the previously indicated zone. The eye tracking system may be one of the many types which are known per se. However, an eye tracking system which has been found to be particularly advantageous is one comprising at least one telecamera for recording the picture of at least the surgeon's eyes and means for calculating the direction of the gaze depending on the picture taken. In particular, as shown schematically inFIG.2, the tracking system21may comprise two telecameras32,33which are arranged alongside each other at a suitable distance so as to record two spatially offset pictures of the surgeon's eyes. The calculation means (for example comprising a suitably programmed microprocessor) present in the tracking system21may thus perform a triangulation of the gaze direction depending on the comparison of the two recorded pictures. Again advantageously, the tracking system may also comprise an infrared light source34for infrared illumination of the eyes, this facilitating detection thereof in the picture recorded. Advantageously the eye tracking system may be integrated with the monitor so that if the latter is moved, the eye tracker may continue to operate correctly. Still with reference toFIG.2, a block diagram of a possible advantageous embodiment of the console is schematically shown. In this embodiment, the system is divided up for the sake of clarity into three main functional blocks or groups. The first block, indicated by40, comprises the components which are involved directly in the movement of the robot arms. The block40contains a first industrial computer41, known per se, provided with a real-time operating system (for example, RT-LINUX) for carrying out in a given predefinable time the commands associated with control of the robots. The computer41is connected to the robot control unit (or units)30via the communications network42. The computer41receives the movement commands from the manipulators17and18, sending them to the robots and emitting signals for operation of the reactive devices43of the manipulators for tactile feedback. Those manual controls which require an immediate system response, such as the pedals20, if used to send, among other things, commands for stopping the movement of the robot, are also advantageously connected to the computer41. The second functional block, which is indicated by44, comprises a second industrial computer45which produces and controls the human machine interface (HMI) which does not require strictly real-time operation. The eye tracking system21, the keyboard19(where necessary) and the other interface controls are connected to this second computer. The computer45also produces the artificial video pictures to be reproduced on the screen22(for example the visual control areas31) and may control any functions for varying the enlargement of the operating field picture. The computers41and45form the computerized system24for controlling the console. The computers41and45and the robot control unit30may communicate with each via the network42. The HMI application managed by the computer45thus allows the robots to be assigned to the manipulators, as well as display of the data relating to each robot, such as the instruments currently mounted, the movement state, the feedback state, the position of rotational fulcrums of the instruments inserted inside the patient's body, the robot condition, the robot connection state, any emergency conditions, etc. The third functional block, indicated by46, deals with reproduction of the pictures on the screen, providing for example the PiP (Picture-in-Picture) function using the signal supplied by the telecamera14recording the operating field and the picture signal47produced in order to display the HMI interface. The third block also comprises the stereo mixer27for three-dimensional viewing. Advantageously, for the PiP function the monitor22is designed with two separate inputs. The main source is displayed in full screen mode by means, for example, of a DVI connection, while at the same time another video input (for example a VGA connection) is displayed as an inset window. The main source (full screen) consists of the 2-dimensional or 3-dimensional view of the endoscope which is received from the endoscope system. The second source comes from the computer45which produces the human machine interface (HMI). During calibration of the eye tracking system21, the full-screen view may also be switched dynamically (for example, by means of a serial command sent from the HMI application to the monitor) to the video signal produced by the computer45. Advantageously, the console may also comprise a system for detecting the distance between screen and surgeon's eyes in order to vary enlargement of the picture of the operating field shown on the screen depending on a variation in the distance detected. Thus, the surgeon may intuitively perform enlargement of the picture by simply moving his/her face towards the screen and, vice versa, increase the viewing area of the operating field, thus reducing enlargement, by moving his/her face away from the screen. The distance detection system may be achieved in various ways, known per se, for example using telemetric ultrasound measurement devices. Advantageously, however, the eye tracking system21may be used, owing to the stereoscopic recording system which allows calculation, by means of triangulation, of the distance of the surgeon's face. This, together with the associated eye detection function of the eye tracking system, allows an accurate real measurement of the distance of the surgeon's viewpoint from the screen to be performed. In addition to an enlargement, the system may also produce a displacement of picture, for example so as to centre the picture, or displace the picture, by means of the gaze, to the right, to the left, upwards or downwards. When the operating field is recorded by a telecamera, preferably an endoscopic telecamera, mounted on one of the robot arms, it has been found to be advantageous for the gaze detection tracking system to allow also control of the movement of this telecamera in the manner depicted inFIGS.4A,3A and3B. When this function is enabled (for example, by entering, by means of visual selection of a suitable area29, the associated activation command), the movement of the eyes over the picture of the operating field causes the movement of the robot arm so as to displace, and advantageously centre on the screen, the zone focused on. Control of the actual movement of the telecamera may also be performed only following pressing of a confirmation pedal or pushbutton, as already described above. In this way, the surgeon is free to move his/her eyes over the picture without displacement of the viewing frame unless the confirmation pedal or pushbutton is simultaneously pressed. If the movement and enlargement functions described above are combined, the system becomes very easy to control, the movements of the gaze displacing the viewing frame on the screen, while the movement of the eyes towards or away from the screen enlarges or diminishes the picture shown. When three-dimensional viewing of the operating field is used, the distance detection system may also be used to signal to the surgeon when he/she is within the optimum distance range from the screen. In fact, usually three-dimensional systems have an optimum distance interval from the screen where the three-dimensional effect is best. Moreover, the combination of 3D and eye tracking system imposes certain constraints with regard to the position and the distance from the screen, said constraints depending on the position of the surgeon, the tracker and the viewing device. The HMI application of the console may be set so as to indicate to the surgeon, by means of various known acoustic and/or optical systems, when he/she is situated in the optimum position with respect to the screen. Moreover, it is also possible to provide a function which indicates whether the distance with respect to the eye tracker is adequate. When the 3D and eye tracker are used together, the appropriate working space may be the same for both of them and the same indicator may perform both functions. The working area of the eye tracker21will generally be chosen so as to be much greater than that for optimum viewing of the three-dimensional picture. For example, an operating range of the tracker lying between 40 and 75 cm has been found to be advantageous, with the possibility of tracking the eyes within a vertical angle of +30° and −10°. The optimum 3D view is obtained at 60-70 cm from the screen (in this range, the information will be perfectly differentiated between right eye and left eye) and therefore falls well within the operating zone of the tracker. However, it will still be possible to view in 3D outside of this range, provided that the surgeon respects the vertical constraint. Beyond the top end and bottom end of the screen, the 3D is lost. At this point it is clear how the predefined objects have been achieved. With the control system and method described it is possible to control the robot arms with tactile sensing, display the view provided by the endoscope in two or three dimensions, together with the HMI application, and activate certain functions using an eye movement tracker. Owing to the use of the eye tracking system, various interesting control possibilities exist. Firstly, among the various functions associated with the eye tracking system, there is that of being able to stop safely the movement of the robot arms if the surgeon is not looking at the picture of the operating field, with movement of the robot arm which is prevented or allowed automatically when the gaze direction detected does not fall or falls within the predetermined zone of the screen. Moreover, the HMI application is intuitive and easy to use since it may be controlled by the surgeon's gaze (together with or without an activation confirmation device). The main advantages are that the surgeon is able to use his/her eyes in order to select and assign the robot arms to the manipulators without removing his/her hands from the manipulators. Obviously, the above description of an embodiment applying the innovative principles of the present invention is provided by way of example of these innovative principles and must therefore not be regarded as limiting the scope of the rights claimed herein. For example, the console forms a remote operation surgical workstation for the robotized system which may be in the same room or at a distance, also using a connection via geographic networks or the like. The main control console is in fact a remote control device which also allows a patient to be operated on outside of the operating theatre and in any location, as long as the communications time delays are limited. The remote surgery system will be suitable for any type of laparoscopic or similar operation. Obviously, here the term “surgeon” is understood as meaning any person who controls the robot system by means of the console. It must be noted that, as can now be easily imagined by the person skilled in the art, the system according to the invention is modular and may for example be configured to use a greater number of robots (for example up to five robots) and also one or two control consoles.

11857279

DETAILED DESCRIPTION 1. Overview. Aspects of the present disclosure may be integrated into a robotically-enabled medical system capable of performing a variety of medical procedures, including both minimally invasive, such as laparoscopy, and non-invasive, such as endoscopy, procedures. Among endoscopic procedures, the system may be capable of performing bronchoscopy, ureteroscopy, gastroscopy, etc. In addition to performing the breadth of procedures, the system may provide additional benefits, such as enhanced imaging and guidance to assist the physician. Additionally, the system may provide the physician with the ability to perform the procedure from an ergonomic position without the need for awkward arm motions and positions. Still further, the system may provide the physician with the ability to perform the procedure with improved ease of use such that one or more of the instruments of the system can be controlled by a single user. Various embodiments will be described below in conjunction with the drawings for purposes of illustration. It should be appreciated that many other implementations of the disclosed concepts are possible, and various advantages can be achieved with the disclosed implementations. Headings are included herein for reference and to aid in locating various sections. These headings are not intended to limit the scope of the concepts described with respect thereto. Such concepts may have applicability throughout the entire specification. A. Robotic System—Cart. The robotically-enabled medical system may be configured in a variety of ways depending on the particular procedure.FIG.1illustrates an embodiment of a cart-based robotically-enabled system10arranged for a diagnostic and/or therapeutic bronchoscopy. During a bronchoscopy, the system10may comprise a cart11having one or more robotic arms12to deliver a medical instrument, such as a steerable endoscope13, which may be a procedure-specific bronchoscope for bronchoscopy, to a natural orifice access point (i.e., the mouth of the patient positioned on a table in the present example) to deliver diagnostic and/or therapeutic tools. As shown, the cart11may be positioned proximate to the patient's upper torso in order to provide access to the access point. Similarly, the robotic arms12may be actuated to position the bronchoscope relative to the access point. The arrangement inFIG.1may also be utilized when performing a gastro-intestinal (GI) procedure with a gastroscope, a specialized endoscope for GI procedures.FIG.2depicts an example embodiment of the cart in greater detail. With continued reference toFIG.1, once the cart11is properly positioned, the robotic arms12may insert the steerable endoscope13into the patient robotically, manually, or a combination thereof. As shown, the steerable endoscope13may comprise at least two telescoping parts, such as an inner leader portion and an outer sheath portion, each portion coupled to a separate instrument driver (also referred to as an instrument drive mechanism (IDM)) from the set of instrument drivers28, each instrument driver coupled to the distal end of an individual robotic arm. This linear arrangement of the instrument drivers28, which facilitates coaxially aligning the leader portion with the sheath portion, creates a “virtual rail”29that may be repositioned in space by manipulating the one or more robotic arms12into different angles and/or positions. The virtual rails described herein are depicted in the Figures using dashed lines, and accordingly the dashed lines do not depict any physical structure of the system. Translation of the instrument drivers28along the virtual rail29telescopes the inner leader portion relative to the outer sheath portion or advances or retracts the endoscope13from the patient. The angle of the virtual rail29may be adjusted, translated, and pivoted based on clinical application or physician preference. For example, in bronchoscopy, the angle and position of the virtual rail29as shown represents a compromise between providing physician access to the endoscope13while minimizing friction that results from bending the endoscope13into the patient's mouth. The endoscope13may be directed down the patient's trachea and lungs after insertion using precise commands from the robotic system until reaching the target destination or operative site. In order to enhance navigation through the patient's lung network and/or reach the desired target, the endoscope13may be manipulated to telescopically extend the inner leader portion from the outer sheath portion to obtain enhanced articulation and greater bend radius. The use of separate instrument drivers28also allows the leader portion and sheath portion to be driven independently of each other. For example, the endoscope13may be directed to deliver a biopsy needle to a target, such as, for example, a lesion or nodule within the lungs of a patient. The needle may be deployed down a working channel that runs the length of the endoscope to obtain a tissue sample to be analyzed by a pathologist. Depending on the pathology results, additional tools may be deployed down the working channel of the endoscope for additional biopsies. After identifying a nodule to be malignant, the endoscope13may endoscopically deliver tools to resect the potentially cancerous tissue. In some instances, diagnostic and therapeutic treatments can be delivered in separate procedures. In those circumstances, the endoscope13may also be used to deliver a fiducial to “mark” the location of the target nodule as well. In other instances, diagnostic and therapeutic treatments may be delivered during the same procedure. The system10may also include a movable tower30, which may be connected via support cables to the cart11to provide support for controls, electronics, fluidics, optics, sensors, and/or power to the cart11. Placing such functionality in the tower30allows for a smaller form factor cart11that may be more easily adjusted and/or repositioned by an operating physician and his/her staff. Additionally, the division of functionality between the cart/table and the support tower30reduces operating room clutter and facilitates improving clinical workflow. While the cart11may be positioned close to the patient, the tower30may be stowed in a remote location to stay out of the way during a procedure. In support of the robotic systems described above, the tower30may include component(s) of a computer-based control system that stores computer program instructions, for example, within a non-transitory computer-readable storage medium such as a persistent magnetic storage drive, solid state drive, etc. The execution of those instructions, whether the execution occurs in the tower30or the cart11, may control the entire system or sub-system(s) thereof. For example, when executed by a processor of the computer system, the instructions may cause the components of the robotics system to actuate the relevant carriages and arm mounts, actuate the robotics arms, and control the medical instruments. For example, in response to receiving the control signal, the motors in the joints of the robotics arms may position the arms into a certain posture. The tower30may also include a pump, flow meter, valve control, and/or fluid access in order to provide controlled irrigation and aspiration capabilities to the system that may be deployed through the endoscope13. These components may also be controlled using the computer system of the tower30. In some embodiments, irrigation and aspiration capabilities may be delivered directly to the endoscope13through separate cable(s). The tower30may include a voltage and surge protector designed to provide filtered and protected electrical power to the cart11, thereby avoiding placement of a power transformer and other auxiliary power components in the cart11, resulting in a smaller, more moveable cart11. The tower30may also include support equipment for the sensors deployed throughout the robotic system10. For example, the tower30may include optoelectronics equipment for detecting, receiving, and processing data received from the optical sensors or cameras throughout the robotic system10. In combination with the control system, such optoelectronics equipment may be used to generate real-time images for display in any number of consoles deployed throughout the system, including in the tower30. Similarly, the tower30may also include an electronic subsystem for receiving and processing signals received from deployed electromagnetic (EM) sensors. The tower30may also be used to house and position an EM field generator for detection by EM sensors in or on the medical instrument. The tower30may also include a console31in addition to other consoles available in the rest of the system, e.g., console mounted on top of the cart. The console31may include a user interface and a display screen, such as a touchscreen, for the physician operator. Consoles in the system10are generally designed to provide both robotic controls as well as preoperative and real-time information of the procedure, such as navigational and localization information of the endoscope13. When the console31is not the only console available to the physician, it may be used by a second operator, such as a nurse, to monitor the health or vitals of the patient and the operation of the system10, as well as to provide procedure-specific data, such as navigational and localization information. In other embodiments, the console30is housed in a body that is separate from the tower30. The tower30may be coupled to the cart11and endoscope13through one or more cables or connections (not shown). In some embodiments, the support functionality from the tower30may be provided through a single cable to the cart11, simplifying and de-cluttering the operating room. In other embodiments, specific functionality may be coupled in separate cabling and connections. For example, while power may be provided through a single power cable to the cart11, the support for controls, optics, fluidics, and/or navigation may be provided through a separate cable. FIG.2provides a detailed illustration of an embodiment of the cart11from the cart-based robotically-enabled system shown inFIG.1. The cart11generally includes an elongated support structure14(often referred to as a “column”), a cart base15, and a console16at the top of the column14. The column14may include one or more carriages, such as a carriage17(alternatively “arm support”) for supporting the deployment of one or more robotic arms12(three shown inFIG.2). The carriage17may include individually configurable arm mounts that rotate along a perpendicular axis to adjust the base of the robotic arms12for better positioning relative to the patient. The carriage17also includes a carriage interface19that allows the carriage17to vertically translate along the column14. The carriage interface19is connected to the column14through slots, such as slot20, that are positioned on opposite sides of the column14to guide the vertical translation of the carriage17. The slot20contains a vertical translation interface to position and hold the carriage17at various vertical heights relative to the cart base15. Vertical translation of the carriage17allows the cart11to adjust the reach of the robotic arms12to meet a variety of table heights, patient sizes, and physician preferences. Similarly, the individually configurable arm mounts on the carriage17allow the robotic arm base21of the robotic arms12to be angled in a variety of configurations. In some embodiments, the slot20may be supplemented with slot covers that are flush and parallel to the slot surface to prevent dirt and fluid ingress into the internal chambers of the column14and the vertical translation interface as the carriage17vertically translates. The slot covers may be deployed through pairs of spring spools positioned near the vertical top and bottom of the slot20. The covers are coiled within the spools until deployed to extend and retract from their coiled state as the carriage17vertically translates up and down. The spring-loading of the spools provides force to retract the cover into a spool when the carriage17translates towards the spool, while also maintaining a tight seal when the carriage17translates away from the spool. The covers may be connected to the carriage17using, for example, brackets in the carriage interface19to ensure proper extension and retraction of the cover as the carriage17translates. The column14may internally comprise mechanisms, such as gears and motors, that are designed to use a vertically aligned lead screw to translate the carriage17in a mechanized fashion in response to control signals generated in response to user inputs, e.g., inputs from the console16. The robotic arms12may generally comprise robotic arm bases21and end effectors22, separated by a series of linkages23that are connected by a series of joints24, each joint comprising an independent actuator, each actuator comprising an independently controllable motor. Each independently controllable joint represents an independent degree of freedom available to the robotic arm12. Each of the robotic arms12may have seven joints, and thus provide seven degrees of freedom. A multitude of joints result in a multitude of degrees of freedom, allowing for “redundant” degrees of freedom. Having redundant degrees of freedom allows the robotic arms12to position their respective end effectors22at a specific position, orientation, and trajectory in space using different linkage positions and joint angles. This allows for the system to position and direct a medical instrument from a desired point in space while allowing the physician to move the arm joints into a clinically advantageous position away from the patient to create greater access, while avoiding arm collisions. The cart base15balances the weight of the column14, carriage17, and robotic arms12over the floor. Accordingly, the cart base15houses heavier components, such as electronics, motors, power supply, as well as components that either enable movement and/or immobilize the cart11. For example, the cart base15includes rollable wheel-shaped casters25that allow for the cart11to easily move around the room prior to a procedure. After reaching the appropriate position, the casters25may be immobilized using wheel locks to hold the cart11in place during the procedure. Positioned at the vertical end of the column14, the console16allows for both a user interface for receiving user input and a display screen (or a dual-purpose device such as, for example, a touchscreen26) to provide the physician user with both preoperative and intraoperative data. Potential preoperative data on the touchscreen26may include preoperative plans, navigation and mapping data derived from preoperative computerized tomography (CT) scans, and/or notes from preoperative patient interviews. Intraoperative data on display may include optical information provided from the tool, sensor and coordinate information from sensors, as well as vital patient statistics, such as respiration, heart rate, and/or pulse. The console16may be positioned and tilted to allow a physician to access the console16from the side of the column14opposite the carriage17. From this position, the physician may view the console16, robotic arms12, and patient while operating the console16from behind the cart11. As shown, the console16also includes a handle27to assist with maneuvering and stabilizing the cart11. FIG.3illustrates an embodiment of a robotically-enabled system10arranged for ureteroscopy. In a ureteroscopic procedure, the cart11may be positioned to deliver a ureteroscope32, a procedure-specific endoscope designed to traverse a patient's urethra and ureter, to the lower abdominal area of the patient. In a ureteroscopy, it may be desirable for the ureteroscope32to be directly aligned with the patient's urethra to reduce friction and forces on the sensitive anatomy in the area. As shown, the cart11may be aligned at the foot of the table to allow the robotic arms12to position the ureteroscope32for direct linear access to the patient's urethra. From the foot of the table, the robotic arms12may insert the ureteroscope32along the virtual rail33directly into the patient's lower abdomen through the urethra. After insertion into the urethra, using similar control techniques as in bronchoscopy, the ureteroscope32may be navigated into the bladder, ureters, and/or kidneys for diagnostic and/or therapeutic applications. For example, the ureteroscope32may be directed into the ureter and kidneys to break up kidney stone build up using a laser or ultrasonic lithotripsy device deployed down the working channel of the ureteroscope32. After lithotripsy is complete, the resulting stone fragments may be removed using baskets deployed down the ureteroscope32. FIG.4illustrates an embodiment of a robotically-enabled system10similarly arranged for a vascular procedure. In a vascular procedure, the system10may be configured such that the cart11may deliver a medical instrument34, such as a steerable catheter, to an access point in the femoral artery in the patient's leg. The femoral artery presents both a larger diameter for navigation as well as a relatively less circuitous and tortuous path to the patient's heart, which simplifies navigation. As in a ureteroscopic procedure, the cart11may be positioned towards the patient's legs and lower abdomen to allow the robotic arms12to provide a virtual rail35with direct linear access to the femoral artery access point in the patient's thigh/hip region. After insertion into the artery, the medical instrument34may be directed and inserted by translating the instrument drivers28. Alternatively, the cart may be positioned around the patient's upper abdomen in order to reach alternative vascular access points, such as, for example, the carotid and brachial arteries near the shoulder and wrist. B. Robotic System—Table. Embodiments of the robotically-enabled medical system may also incorporate the patient's table. Incorporation of the table reduces the amount of capital equipment within the operating room by removing the cart, which allows greater access to the patient.FIG.5illustrates an embodiment of such a robotically-enabled system arranged for a bronchoscopic procedure. System36includes a support structure or column37for supporting platform38(shown as a “table” or “bed”) over the floor. Much like in the cart-based systems, the end effectors of the robotic arms39of the system36comprise instrument drivers42that are designed to manipulate an elongated medical instrument, such as a bronchoscope40inFIG.5, through or along a virtual rail41formed from the linear alignment of the instrument drivers42. In practice, a C-arm for providing fluoroscopic imaging may be positioned over the patient's upper abdominal area by placing the emitter and detector around the table38. FIG.6provides an alternative view of the system36without the patient and medical instrument for discussion purposes. As shown, the column37may include one or more carriages43shown as ring-shaped in the system36, from which the one or more robotic arms39may be based. The carriages43may translate along a vertical column interface44that runs the length of the column37to provide different vantage points from which the robotic arms39may be positioned to reach the patient. The carriage(s)43may rotate around the column37using a mechanical motor positioned within the column37to allow the robotic arms39to have access to multiples sides of the table38, such as, for example, both sides of the patient. In embodiments with multiple carriages, the carriages may be individually positioned on the column and may translate and/or rotate independently of the other carriages. While the carriages43need not surround the column37or even be circular, the ring-shape as shown facilitates rotation of the carriages43around the column37while maintaining structural balance. Rotation and translation of the carriages43allows the system36to align the medical instruments, such as endoscopes and laparoscopes, into different access points on the patient. In other embodiments (not shown), the system36can include a patient table or bed with adjustable arm supports in the form of bars or rails extending alongside it. One or more robotic arms39(e.g., via a shoulder with an elbow joint) can be attached to the adjustable arm supports, which can be vertically adjusted. By providing vertical adjustment, the robotic arms39are advantageously capable of being stowed compactly beneath the patient table or bed, and subsequently raised during a procedure. The robotic arms39may be mounted on the carriages43through a set of arm mounts45comprising a series of joints that may individually rotate and/or telescopically extend to provide additional configurability to the robotic arms39. Additionally, the arm mounts45may be positioned on the carriages43such that, when the carriages43are appropriately rotated, the arm mounts45may be positioned on either the same side of the table38(as shown inFIG.6), on opposite sides of the table38(as shown inFIG.9), or on adjacent sides of the table38(not shown). The column37structurally provides support for the table38, and a path for vertical translation of the carriages43. Internally, the column37may be equipped with lead screws for guiding vertical translation of the carriages, and motors to mechanize the translation of the carriages43based the lead screws. The column37may also convey power and control signals to the carriages43and the robotic arms39mounted thereon. The table base46serves a similar function as the cart base15in the cart11shown inFIG.2, housing heavier components to balance the table/bed38, the column37, the carriages43, and the robotic arms39. The table base46may also incorporate rigid casters to provide stability during procedures. Deployed from the bottom of the table base46, the casters may extend in opposite directions on both sides of the base46and retract when the system36needs to be moved. With continued reference toFIG.6, the system36may also include a tower (not shown) that divides the functionality of the system36between the table and the tower to reduce the form factor and bulk of the table. As in earlier disclosed embodiments, the tower may provide a variety of support functionalities to the table, such as processing, computing, and control capabilities, power, fluidics, and/or optical and sensor processing. The tower may also be movable to be positioned away from the patient to improve physician access and de-clutter the operating room. Additionally, placing components in the tower allows for more storage space in the table base46for potential stowage of the robotic arms39. The tower may also include a master controller or console that provides both a user interface for user input, such as keyboard and/or pendant, as well as a display screen (or touchscreen) for preoperative and intraoperative information, such as real-time imaging, navigation, and tracking information. In some embodiments, the tower may also contain holders for gas tanks to be used for insufflation. In some embodiments, a table base may stow and store the robotic arms when not in use.FIG.7illustrates a system47that stows robotic arms in an embodiment of the table-based system. In the system47, carriages48may be vertically translated into base49to stow robotic arms50, arm mounts51, and the carriages48within the base49. Base covers52may be translated and retracted open to deploy the carriages48, arm mounts51, and robotic arms50around column53, and closed to stow to protect them when not in use. The base covers52may be sealed with a membrane54along the edges of its opening to prevent dirt and fluid ingress when closed. FIG.8illustrates an embodiment of a robotically-enabled table-based system configured for a ureteroscopic procedure. In a ureteroscopy, the table38may include a swivel portion55for positioning a patient off-angle from the column37and table base46. The swivel portion55may rotate or pivot around a pivot point (e.g., located below the patient's head) in order to position the bottom portion of the swivel portion55away from the column37. For example, the pivoting of the swivel portion55allows a C-arm (not shown) to be positioned over the patient's lower abdomen without competing for space with the column (not shown) below table38. By rotating the carriage35(not shown) around the column37, the robotic arms39may directly insert a ureteroscope56along a virtual rail57into the patient's groin area to reach the urethra. In a ureteroscopy, stirrups58may also be fixed to the swivel portion55of the table38to support the position of the patient's legs during the procedure and allow clear access to the patient's groin area. In a laparoscopic procedure, through small incision(s) in the patient's abdominal wall, minimally invasive instruments may be inserted into the patient's anatomy. In some embodiments, the minimally invasive instruments comprise an elongated rigid member, such as a shaft, which is used to access anatomy within the patient. After inflation of the patient's abdominal cavity, the instruments may be directed to perform surgical or medical tasks, such as grasping, cutting, ablating, suturing, etc. In some embodiments, the instruments can comprise a scope, such as a laparoscope.FIG.9illustrates an embodiment of a robotically-enabled table-based system configured for a laparoscopic procedure. As shown inFIG.9, the carriages43of the system36may be rotated and vertically adjusted to position pairs of the robotic arms39on opposite sides of the table38, such that instrument59may be positioned using the arm mounts45to be passed through minimal incisions on both sides of the patient to reach his/her abdominal cavity. To accommodate laparoscopic procedures, the robotically-enabled table system may also tilt the platform to a desired angle.FIG.10illustrates an embodiment of the robotically-enabled medical system with pitch or tilt adjustment. As shown inFIG.10, the system36may accommodate tilt of the table38to position one portion of the table at a greater distance from the floor than the other. Additionally, the arm mounts45may rotate to match the tilt such that the robotic arms39maintain the same planar relationship with the table38. To accommodate steeper angles, the column37may also include telescoping portions60that allow vertical extension of the column37to keep the table38from touching the floor or colliding with the table base46. FIG.11provides a detailed illustration of the interface between the table38and the column37. Pitch rotation mechanism61may be configured to alter the pitch angle of the table38relative to the column37in multiple degrees of freedom. The pitch rotation mechanism61may be enabled by the positioning of orthogonal axes1,2at the column-table interface, each axis actuated by a separate motor3,4responsive to an electrical pitch angle command. Rotation along one screw5would enable tilt adjustments in one axis1, while rotation along the other screw6would enable tilt adjustments along the other axis2. In some embodiments, a ball joint can be used to alter the pitch angle of the table38relative to the column37in multiple degrees of freedom. For example, pitch adjustments are particularly useful when trying to position the table in a Trendelenburg position, i.e., position the patient's lower abdomen at a higher position from the floor than the patient's upper abdomen, for lower abdominal surgery. The Trendelenburg position causes the patient's internal organs to slide towards his/her upper abdomen through the force of gravity, clearing out the abdominal cavity for minimally invasive tools to enter and perform lower abdominal surgical or medical procedures, such as laparoscopic prostatectomy. FIGS.12and13illustrate isometric and end views of an alternative embodiment of a table-based surgical robotics system100. The surgical robotics system100includes one or more adjustable arm supports105that can be configured to support one or more robotic arms (see, for example,FIG.14) relative to a table101. In the illustrated embodiment, a single adjustable arm support105is shown, though an additional arm support can be provided on an opposite side of the table101. The adjustable arm support105can be configured so that it can move relative to the table101to adjust and/or vary the position of the adjustable arm support105and/or any robotic arms mounted thereto relative to the table101. For example, the adjustable arm support105may be adjusted one or more degrees of freedom relative to the table101. The adjustable arm support105provides high versatility to the system100, including the ability to easily stow the one or more adjustable arm supports105and any robotics arms attached thereto beneath the table101. The adjustable arm support105can be elevated from the stowed position to a position below an upper surface of the table101. In other embodiments, the adjustable arm support105can be elevated from the stowed position to a position above an upper surface of the table101. The adjustable arm support105can provide several degrees of freedom, including lift, lateral translation, tilt, etc. In the illustrated embodiment ofFIGS.12and13, the arm support105is configured with four degrees of freedom, which are illustrated with arrows inFIG.12. A first degree of freedom allows for adjustment of the adjustable arm support105in the z-direction (“Z-lift”). For example, the adjustable arm support105can include a carriage109configured to move up or down along or relative to a column102supporting the table101. A second degree of freedom can allow the adjustable arm support105to tilt. For example, the adjustable arm support105can include a rotary joint, which can allow the adjustable arm support105to be aligned with the bed in a Trendelenburg position. A third degree of freedom can allow the adjustable arm support105to “pivot up,” which can be used to adjust a distance between a side of the table101and the adjustable arm support105. A fourth degree of freedom can permit translation of the adjustable arm support105along a longitudinal length of the table. The surgical robotics system100inFIGS.12and13can comprise a table supported by a column102that is mounted to a base103. The base103and the column102support the table101relative to a support surface. A floor axis131and a support axis133are shown inFIG.13. The adjustable arm support105can be mounted to the column102. In other embodiments, the arm support105can be mounted to the table101or base103. The adjustable arm support105can include a carriage109, a bar or rail connector111and a bar or rail107. In some embodiments, one or more robotic arms mounted to the rail107can translate and move relative to one another. The carriage109can be attached to the column102by a first joint113, which allows the carriage109to move relative to the column102(e.g., such as up and down a first or vertical axis123). The first joint113can provide the first degree of freedom (“Z-lift”) to the adjustable arm support105. The adjustable arm support105can include a second joint115, which provides the second degree of freedom (tilt) for the adjustable arm support105. The adjustable arm support105can include a third joint117, which can provide the third degree of freedom (“pivot up”) for the adjustable arm support105. An additional joint119(shown inFIG.13) can be provided that mechanically constrains the third joint117to maintain an orientation of the rail107as the rail connector111is rotated about a third axis127. The adjustable arm support105can include a fourth joint121, which can provide a fourth degree of freedom (translation) for the adjustable arm support105along a fourth axis129. FIG.14illustrates an end view of the surgical robotics system140A with two adjustable arm supports105A,105B mounted on opposite sides of a table101. A first robotic arm142A is attached to the bar or rail107A of the first adjustable arm support105B. The first robotic arm142A includes a base144A attached to the rail107A. The distal end of the first robotic arm142A includes an instrument drive mechanism146A that can attach to one or more robotic medical instruments or tools. Similarly, the second robotic arm142B includes a base144B attached to the rail107B. The distal end of the second robotic arm142B includes an instrument drive mechanism146B. The instrument drive mechanism146B can be configured to attach to one or more robotic medical instruments or tools. In some embodiments, one or more of the robotic arms142A,142B comprises an arm with seven or more degrees of freedom. In some embodiments, one or more of the robotic arms142A,142B can include eight degrees of freedom, including an insertion axis (1-degree of freedom including insertion), a wrist (3-degrees of freedom including wrist pitch, yaw and roll), an elbow (1-degree of freedom including elbow pitch), a shoulder (2-degrees of freedom including shoulder pitch and yaw), and base144A,144B (1-degree of freedom including translation). In some embodiments, the insertion degree of freedom can be provided by the robotic arm142A,142B, while in other embodiments, the instrument itself provides insertion via an instrument-based insertion architecture. C. Instrument Driver & Interface. The end effectors of the system's robotic arms may comprise (i) an instrument driver (alternatively referred to as “instrument drive mechanism” or “instrument device manipulator”) that incorporates electro-mechanical means for actuating the medical instrument and (ii) a removable or detachable medical instrument, which may be devoid of any electro-mechanical components, such as motors. This dichotomy may be driven by the need to sterilize medical instruments used in medical procedures, and the inability to adequately sterilize expensive capital equipment due to their intricate mechanical assemblies and sensitive electronics. Accordingly, the medical instruments may be designed to be detached, removed, and interchanged from the instrument driver (and thus the system) for individual sterilization or disposal by the physician or the physician's staff. In contrast, the instrument drivers need not be changed or sterilized, and may be draped for protection. FIG.15illustrates an example instrument driver. Positioned at the distal end of a robotic arm, instrument driver62comprises one or more drive units63arranged with parallel axes to provide controlled torque to a medical instrument via drive shafts64. Each drive unit63comprises an individual drive shaft64for interacting with the instrument, a gear head65for converting the motor shaft rotation to a desired torque, a motor66for generating the drive torque, an encoder67to measure the speed of the motor shaft and provide feedback to the control circuitry, and control circuitry68for receiving control signals and actuating the drive unit. Each drive unit63being independently controlled and motorized, the instrument driver62may provide multiple (four as shown inFIG.15) independent drive outputs to the medical instrument. In operation, the control circuitry68would receive a control signal, transmit a motor signal to the motor66, compare the resulting motor speed as measured by the encoder67with the desired speed, and modulate the motor signal to generate the desired torque. For procedures that require a sterile environment, the robotic system may incorporate a drive interface, such as a sterile adapter connected to a sterile drape, that sits between the instrument driver and the medical instrument. The chief purpose of the sterile adapter is to transfer angular motion from the drive shafts of the instrument driver to the drive inputs of the instrument while maintaining physical separation, and thus sterility, between the drive shafts and drive inputs. Accordingly, an example sterile adapter may comprise a series of rotational inputs and outputs intended to be mated with the drive shafts of the instrument driver and drive inputs on the instrument. Connected to the sterile adapter, the sterile drape, comprised of a thin, flexible material such as transparent or translucent plastic, is designed to cover the capital equipment, such as the instrument driver, robotic arm, and cart (in a cart-based system) or table (in a table-based system). Use of the drape would allow the capital equipment to be positioned proximate to the patient while still being located in an area not requiring sterilization (i.e., non-sterile field). On the other side of the sterile drape, the medical instrument may interface with the patient in an area requiring sterilization (i.e., sterile field). D. Medical Instrument. FIG.16illustrates an example medical instrument with a paired instrument driver. Like other instruments designed for use with a robotic system, medical instrument70comprises an elongated shaft71(or elongate body) and an instrument base72. The instrument base72, also referred to as an “instrument handle” due to its intended design for manual interaction by the physician, may generally comprise rotatable drive inputs73, e.g., receptacles, pulleys or spools, that are designed to be mated with drive outputs74that extend through a drive interface on instrument driver75at the distal end of robotic arm76. When physically connected, latched, and/or coupled, the mated drive inputs73of the instrument base72may share axes of rotation with the drive outputs74in the instrument driver75to allow the transfer of torque from the drive outputs74to the drive inputs73. In some embodiments, the drive outputs74may comprise splines that are designed to mate with receptacles on the drive inputs73. The elongated shaft71is designed to be delivered through either an anatomical opening or lumen, e.g., as in endoscopy, or a minimally invasive incision, e.g., as in laparoscopy. The elongated shaft71may be either flexible (e.g., having properties similar to an endoscope) or rigid (e.g., having properties similar to a laparoscope) or contain a customized combination of both flexible and rigid portions. When designed for laparoscopy, the distal end of a rigid elongated shaft may be connected to an end effector extending from a jointed wrist formed from a clevis with at least one degree of freedom and a surgical tool or medical instrument, such as, for example, a grasper or scissors, that may be actuated based on force from the tendons as the drive inputs rotate in response to torque received from the drive outputs74of the instrument driver75. When designed for endoscopy, the distal end of a flexible elongated shaft may include a steerable or controllable bending section that may be articulated and bent based on torque received from the drive outputs74of the instrument driver75. Torque from the instrument driver75is transmitted down the elongated shaft71using tendons along the elongated shaft71. These individual tendons, such as pull wires, may be individually anchored to individual drive inputs73within the instrument handle72. From the handle72, the tendons are directed down one or more pull lumens along the elongated shaft71and anchored at the distal portion of the elongated shaft71, or in the wrist at the distal portion of the elongated shaft. During a surgical procedure, such as a laparoscopic, endoscopic or hybrid procedure, these tendons may be coupled to a distally mounted end effector, such as a wrist, grasper, or scissor. Under such an arrangement, torque exerted on drive inputs73would transfer tension to the tendon, thereby causing the end effector to actuate in some way. In some embodiments, during a surgical procedure, the tendon may cause a joint to rotate about an axis, thereby causing the end effector to move in one direction or another. Alternatively, the tendon may be connected to one or more jaws of a grasper at the distal end of the elongated shaft71, where tension from the tendon causes the grasper to close. In endoscopy, the tendons may be coupled to a bending or articulating section positioned along the elongated shaft71(e.g., at the distal end) via adhesive, control ring, or other mechanical fixation. When fixedly attached to the distal end of a bending section, torque exerted on the drive inputs73would be transmitted down the tendons, causing the softer, bending section (sometimes referred to as the articulable section or region) to bend or articulate. Along the non-bending sections, it may be advantageous to spiral or helix the individual pull lumens that direct the individual tendons along (or inside) the walls of the endoscope shaft to balance the radial forces that result from tension in the pull wires. The angle of the spiraling and/or spacing therebetween may be altered or engineered for specific purposes, wherein tighter spiraling exhibits lesser shaft compression under load forces, while lower amounts of spiraling results in greater shaft compression under load forces, but limits bending. On the other end of the spectrum, the pull lumens may be directed parallel to the longitudinal axis of the elongated shaft71to allow for controlled articulation in the desired bending or articulable sections. In endoscopy, the elongated shaft71houses a number of components to assist with the robotic procedure. The shaft71may comprise a working channel for deploying surgical tools (or medical instruments), irrigation, and/or aspiration to the operative region at the distal end of the shaft71. The shaft71may also accommodate wires and/or optical fibers to transfer signals to/from an optical assembly at the distal tip, which may include an optical camera. The shaft71may also accommodate optical fibers to carry light from proximally-located light sources, such as light emitting diodes, to the distal end of the shaft71. At the distal end of the instrument70, the distal tip may also comprise the opening of a working channel for delivering tools for diagnostic and/or therapy, irrigation, and aspiration to an operative site. The distal tip may also include a port for a camera, such as a fiberscope or a digital camera, to capture images of an internal anatomical space. Relatedly, the distal tip may also include ports for light sources for illuminating the anatomical space when using the camera. In the example ofFIG.16, the drive shaft axes, and thus the drive input axes, are orthogonal to the axis of the elongated shaft71. This arrangement, however, complicates roll capabilities for the elongated shaft71. Rolling the elongated shaft71along its axis while keeping the drive inputs73static results in undesirable tangling of the tendons as they extend off the drive inputs73and enter pull lumens within the elongated shaft71. The resulting entanglement of such tendons may disrupt any control algorithms intended to predict movement of the flexible elongated shaft71during an endoscopic procedure. FIG.17illustrates an alternative design for an instrument driver and instrument where the axes of the drive units are parallel to the axis of the elongated shaft of the instrument. As shown, a circular instrument driver80comprises four drive units with their drive outputs81aligned in parallel at the end of a robotic arm82. The drive units, and their respective drive outputs81, are housed in a rotational assembly83of the instrument driver80that is driven by one of the drive units within the assembly83. In response to torque provided by the rotational drive unit, the rotational assembly83rotates along a circular bearing that connects the rotational assembly83to the non-rotational portion84of the instrument driver80. Power and controls signals may be communicated from the non-rotational portion84of the instrument driver80to the rotational assembly83through electrical contacts that may be maintained through rotation by a brushed slip ring connection (not shown). In other embodiments, the rotational assembly83may be responsive to a separate drive unit that is integrated into the non-rotatable portion84, and thus not in parallel to the other drive units. The rotational mechanism83allows the instrument driver80to rotate the drive units, and their respective drive outputs81, as a single unit around an instrument driver axis85. Like earlier disclosed embodiments, an instrument86may comprise an elongated shaft portion88and an instrument base87(shown with a transparent external skin for discussion purposes) comprising a plurality of drive inputs89(such as receptacles, pulleys, and spools) that are configured to receive the drive outputs81in the instrument driver80. Unlike prior disclosed embodiments, the instrument shaft88extends from the center of the instrument base87with an axis substantially parallel to the axes of the drive inputs89, rather than orthogonal as in the design ofFIG.16. When coupled to the rotational assembly83of the instrument driver80, the medical instrument86, comprising instrument base87and instrument shaft88, rotates in combination with the rotational assembly83about the instrument driver axis85. Since the instrument shaft88is positioned at the center of instrument base87, the instrument shaft88is coaxial with instrument driver axis85when attached. Thus, rotation of the rotational assembly83causes the instrument shaft88to rotate about its own longitudinal axis. Moreover, as the instrument base87rotates with the instrument shaft88, any tendons connected to the drive inputs89in the instrument base87are not tangled during rotation. Accordingly, the parallelism of the axes of the drive outputs81, drive inputs89, and instrument shaft88allows for the shaft rotation without tangling any control tendons. FIG.18illustrates an instrument having an instrument based insertion architecture in accordance with some embodiments. The instrument150can be coupled to any of the instrument drivers discussed above. The instrument150comprises an elongated shaft152, an end effector162connected to the shaft152, and a handle170coupled to the shaft152. The elongated shaft152comprises a tubular member having a proximal portion154and a distal portion156. The elongated shaft152comprises one or more channels or grooves158along its outer surface. The grooves158are configured to receive one or more wires or cables180therethrough. One or more cables180thus run along an outer surface of the elongated shaft152. In other embodiments, cables180can also run through the elongated shaft152. Manipulation of the one or more cables180(e.g., via an instrument driver) results in actuation of the end effector162. The instrument handle170, which may also be referred to as an instrument base, may generally comprise an attachment interface172having one or more mechanical inputs174, e.g., receptacles, pulleys or spools, that are designed to be reciprocally mated with one or more torque couplers on an attachment surface of an instrument driver. In some embodiments, the instrument150comprises a series of pulleys or cables that enable the elongated shaft152to translate relative to the handle170. In other words, the instrument150itself comprises an instrument-based insertion architecture that accommodates insertion of the instrument, thereby minimizing the reliance on a robot arm to provide insertion of the instrument150. In other embodiments, a robotic arm can be largely responsible for instrument insertion. E. Controller. Any of the robotic systems described herein can include an input device or controller for manipulating an instrument attached to a robotic arm. In some embodiments, the controller can be coupled (e.g., communicatively, electronically, electrically, wirelessly and/or mechanically) with an instrument such that manipulation of the controller causes a corresponding manipulation of the instrument e.g., via master slave control. FIG.19is a perspective view of an embodiment of a controller182. In the present embodiment, the controller182comprises a hybrid controller that can have both impedance and admittance control. In other embodiments, the controller182can utilize just impedance or passive control. In other embodiments, the controller182can utilize just admittance control. By being a hybrid controller, the controller182advantageously can have a lower perceived inertia while in use. In the illustrated embodiment, the controller182is configured to allow manipulation of two medical instruments, and includes two handles184. Each of the handles184is connected to a gimbal186. Each gimbal186is connected to a positioning platform188. As shown inFIG.19, each positioning platform188includes a SCARA arm (selective compliance assembly robot arm)198coupled to a column194by a prismatic joint196. The prismatic joints196are configured to translate along the column194(e.g., along rails197) to allow each of the handles184to be translated in the z-direction, providing a first degree of freedom. The SCARA arm198is configured to allow motion of the handle184in an x-y plane, providing two additional degrees of freedom. In some embodiments, one or more load cells are positioned in the controller. For example, in some embodiments, a load cell (not shown) is positioned in the body of each of the gimbals186. By providing a load cell, portions of the controller182are capable of operating under admittance control, thereby advantageously reducing the perceived inertia of the controller while in use. In some embodiments, the positioning platform188is configured for admittance control, while the gimbal186is configured for impedance control. In other embodiments, the gimbal186is configured for admittance control, while the positioning platform188is configured for impedance control. Accordingly, for some embodiments, the translational or positional degrees of freedom of the positioning platform188can rely on admittance control, while the rotational degrees of freedom of the gimbal186rely on impedance control. F. Navigation and Control. Traditional endoscopy may involve the use of fluoroscopy (e.g., as may be delivered through a C-arm) and other forms of radiation-based imaging modalities to provide endoluminal guidance to an operator physician. In contrast, the robotic systems contemplated by this disclosure can provide for non-radiation-based navigational and localization means to reduce physician exposure to radiation and reduce the amount of equipment within the operating room. As used herein, the term “localization” may refer to determining and/or monitoring the position of objects in a reference coordinate system. Technologies such as preoperative mapping, computer vision, real-time EM tracking, and robot command data may be used individually or in combination to achieve a radiation-free operating environment. In other cases, where radiation-based imaging modalities are still used, the preoperative mapping, computer vision, real-time EM tracking, and robot command data may be used individually or in combination to improve upon the information obtained solely through radiation-based imaging modalities. FIG.20is a block diagram illustrating a localization system90that estimates a location of one or more elements of the robotic system, such as the location of the instrument, in accordance to an example embodiment. The localization system90may be a set of one or more computer devices configured to execute one or more instructions. The computer devices may be embodied by a processor (or processors) and computer-readable memory in one or more components discussed above. By way of example and not limitation, the computer devices may be in the tower30shown inFIG.1, the cart11shown inFIGS.1-4, the beds shown inFIGS.5-14, etc. As shown inFIG.20, the localization system90may include a localization module95that processes input data91-94to generate location data96for the distal tip of a medical instrument. The location data96may be data or logic that represents a location and/or orientation of the distal end of the instrument relative to a frame of reference. The frame of reference can be a frame of reference relative to the anatomy of the patient or to a known object, such as an EM field generator (see discussion below for the EM field generator). The various input data91-94are now described in greater detail. Preoperative mapping may be accomplished through the use of the collection of low dose CT scans. Preoperative CT scans are reconstructed into three-dimensional images, which are visualized, e.g. as “slices” of a cutaway view of the patient's internal anatomy. When analyzed in the aggregate, image-based models for anatomical cavities, spaces and structures of the patient's anatomy, such as a patient lung network, may be generated. Techniques such as center-line geometry may be determined and approximated from the CT images to develop a three-dimensional volume of the patient's anatomy, referred to as model data91(also referred to as “preoperative model data” when generated using only preoperative CT scans). The use of center-line geometry is discussed in U.S. patent application Ser. No. 14/523,760, published as U.S. Pub. No. 2014/0336747 on Nov. 13, 2014, the contents of which are herein incorporated in its entirety. Network topological models may also be derived from the CT-images, and are particularly appropriate for bronchoscopy. In some embodiments, the instrument may be equipped with a camera to provide vision data (or image data)92. The localization module95may process the vision data92to enable one or more vision-based (or image-based) location tracking modules or features. For example, the preoperative model data91may be used in conjunction with the vision data92to enable computer vision-based tracking of the medical instrument (e.g., an endoscope or an instrument advance through a working channel of the endoscope). For example, using the preoperative model data91, the robotic system may generate a library of expected endoscopic images from the model based on the expected path of travel of the endoscope, each image linked to a location within the model. Intraoperatively, this library may be referenced by the robotic system in order to compare real-time images captured at the camera (e.g., a camera at a distal end of the endoscope) to those in the image library to assist localization. Other computer vision-based tracking techniques use feature tracking to determine motion of the camera, and thus the endoscope. Some features of the localization module95may identify circular geometries in the preoperative model data91that correspond to anatomical lumens and track the change of those geometries to determine which anatomical lumen was selected, as well as the relative rotational and/or translational motion of the camera. Use of a topological map may further enhance vision-based algorithms or techniques. Optical flow, another computer vision-based technique, may analyze the displacement and translation of image pixels in a video sequence in the vision data92to infer camera movement. Examples of optical flow techniques may include motion detection, object segmentation calculations, luminance, motion compensated encoding, stereo disparity measurement, etc. Through the comparison of multiple frames over multiple iterations, movement and location of the camera (and thus the endoscope) may be determined. The localization module95may use real-time EM tracking to generate a real-time location of the endoscope in a global coordinate system that may be registered to the patient's anatomy, represented by the preoperative model. In EM tracking, an EM sensor (or tracker) comprising one or more sensor coils embedded in one or more locations and orientations in a medical instrument (e.g., an endoscopic tool) measures the variation in the EM field created by one or more static EM field generators positioned at a known location. The location information detected by the EM sensors is stored as EM data93. The EM field generator (or transmitter), may be placed close to the patient to create a low intensity magnetic field that the embedded sensor may detect. The magnetic field induces small currents in the sensor coils of the EM sensor, which may be analyzed to determine the distance and angle between the EM sensor and the EM field generator. These distances and orientations may be intraoperatively “registered” to the patient anatomy (e.g., the preoperative model) in order to determine the geometric transformation that aligns a single location in the coordinate system with a position in the preoperative model of the patient's anatomy. Once registered, an embedded EM tracker in one or more positions of the medical instrument (e.g., the distal tip of an endoscope) may provide real-time indications of the progression of the medical instrument through the patient's anatomy. Robotic command and kinematics data94may also be used by the localization module95to provide localization data96for the robotic system. Device pitch and yaw resulting from articulation commands may be determined during preoperative calibration. Intraoperatively, these calibration measurements may be used in combination with known insertion depth information to estimate the position of the instrument. Alternatively, these calculations may be analyzed in combination with EM, vision, and/or topological modeling to estimate the position of the medical instrument within the network. AsFIG.20shows, a number of other input data can be used by the localization module95. For example, although not shown inFIG.20, an instrument utilizing shape-sensing fiber can provide shape data that the localization module95can use to determine the location and shape of the instrument. The localization module95may use the input data91-94in combination(s). In some cases, such a combination may use a probabilistic approach where the localization module95assigns a confidence weight to the location determined from each of the input data91-94. Thus, where the EM data may not be reliable (as may be the case where there is EM interference) the confidence of the location determined by the EM data93can be decrease and the localization module95may rely more heavily on the vision data92and/or the robotic command and kinematics data94. As discussed above, the robotic systems discussed herein may be designed to incorporate a combination of one or more of the technologies above. The robotic system's computer-based control system, based in the tower, bed and/or cart, may store computer program instructions, for example, within a non-transitory computer-readable storage medium such as a persistent magnetic storage drive, solid state drive, or the like, that, upon execution, cause the system to receive and analyze sensor data and user commands, generate control signals throughout the system, and display the navigational and localization data, such as the position of the instrument within the global coordinate system, anatomical map, etc. 2. Introduction to Bipolar Medical Instruments. Embodiments of the disclosure relate to a bipolar medical instrument which can be used to cauterize tissue. The bipolar medical instrument can be attached to an IDM at a distal end or portion of a robotic arm such that the bipolar medical instrument can be controlled by a robotic system. A pair of end effectors located at the distal end of the bipolar medical instrument may be embodied as a pair of forceps or a grasper. The end effectors can cauterize (e.g., burn) or seal patient tissue positioned between them in a controlled manner by applying electrical energy to the end effectors (e.g., jaws of the grasper). For example, a voltage difference can be applied between a first end effector (e.g., a first jaw of a grasper) and a second end effector (e.g., a second jaw of the grasper), thereby causing current to flow from the first end effector to the second end effector. The heated area can therefore be confined to the patient's tissue in the region between the first and second end effectors (e.g., the first and second jaws of the grasper). The use of such a bipolar medical instrument for cauterization may facilitate better control of current and heat near the target area, resulting in fewer inadvertent patient burns. The bipolar medical instrument may be electrically coupled to a generator (e.g., an electrosurgical unit (ESU)) configured to apply a voltage difference between two end effectors, thereby causing an electric current to flow between the end effectors. To ensure that the current flows between the end effectors, rather than through a short in another location within the bipolar medical instrument, the two electrical paths supplying the voltage difference to the end effectors are electrically isolated from each other. One technique for electrically isolating the end effects is to utilize distal pulleys that are formed of an electrically insulating material, which are mechanically fixed to the end effectors. However, due to the material properties of such electrically insulating material, the distal pulleys may occupy a larger area than distal pulleys formed of metal that provide similar functionality. As using distal pulleys formed of metal can reduce distal pulley size, the overall diameter of the bipolar medical instrument can be decreased, thereby allowing the distal pulleys to fit in a smaller diameter wrist (e.g., a 5-5.5 mm outer diameter wrist). By having a smaller diameter wrist, this can result in a smaller incision formed in a patient during surgery. Thus, aspects of this disclosure relate to systems and techniques for electrically isolating the electrical paths providing the voltage difference to the end effectors of a bipolar medical instrument, while maintaining an instrument of relatively small diameter. A. Bipolar Medical Instruments Including a Single Isolated Grip FIGS.21A-21Dillustrate a plurality of views of an embodiment of a bipolar medical instrument having a single isolated grip in accordance with aspects of this disclosure. In particular,FIG.21Aillustrates a view of the bipolar medical instrument200in which a wrist201is visible.FIGS.21B and21Cillustrate additional views of the bipolar medical instrument200in which the wrist201is illustrated as transparent to provide a view of the internals of the wrist201.FIG.21Dillustrates another view of the bipolar medical instrument200in which the wrist201is not shown to provide a view of cable paths within the wrist201. With reference toFIGS.21A and21B, the bipolar medical instrument200includes the wrist201and an end effector220. The wrist201includes a distal clevis205and a proximal clevis210. The end effector220may comprise a first end effector221and a second end effector223. In some embodiments, the end effector220may be a grasping device, wherein the first end effector221may include a first jaw and the second end effector223may include a second jaw. The bipolar medical instrument200may further include an insulating member (also referred to as an insulating skirt)225, a first electrical cable230, a second electrical cable235, a set of one or more distal pulleys240, a distal axle241, a set of one or more proximal pulleys245, a proximal axle246, a set of one or more proximal redirect pulleys250, and a proximal redirect axle251. Further, as illustrated inFIG.21D, the bipolar medical instrument200further includes a first drive cable260including two first cable segments261and263, and a second drive cable265including two second cable segments267and269. Referring to the cable paths illustrated inFIG.21D, the bipolar medical instrument200may be configured to be actuated in accordance with an N+1 actuation technique, where N is a number of degrees of freedom (DOF) in which the wrist201is configured to be actuated and N+1 is a number of cable segments configured to control actuation of the wrist201. For example, the first end effector221may be actuated in a first DOF with respect to the distal axle241(e.g., defining a yaw axis) by the two first cable segments261and263(e.g., by advancing one of the first cable segments261,263while retracting the other of the first cable segments261,263). Similarly, the second end effector223may be actuated in a second DOF with respect to the distal axle241by the two second cable segments267and269(e.g., by advancing one of the second cable segments267,269while retracting the other of the second cable segments267,269). The distal clevis205may be actuated in a third DOF with respect to the proximal axle246(e.g., defining a pitch axis) by advancing both of the first cable segments261and263while retracting both of the second cable segments267and269, or vice versa. In the embodiment ofFIGS.21A-21D, since there are four cable segments261,263,267, and269(e.g., N+1=4), the bipolar medical instrument200may be configured for actuation in three DOF (e.g., N=3). By coordinating the control of the actuation of both the first and second end effectors221and223(e.g., by a processor of the robotic system10ofFIG.1), the system may be able to provide three DOF control to a user, including yaw control (movement of both end effectors221and223in the same direction), pitch control (movement of the distal clevis205), and grip control (contracting or separating the end effectors221and223) of the bipolar medical instrument200. As shown in the cable path ofFIG.21D, in one embodiment, there may be pulleys that are not shared by the first cable segments261and263and the second cable segments267and269(e.g., each cable segment may be engaged with its own one of the proximal pulleys245and proximal redirect pulleys250). However, the first electrical cable230and the second electrical cable235may share one of each of the proximal pulleys245and proximal redirect pulleys250. For example, with respect to the shared proximal pulley245, the first electrical cable230may run on one side of the shared proximal pulley245and the second electrical cable235may run on the other side of the shared proximal pulley245. The distal ends of the first and second end effectors221and223may have a plurality of teeth arranged facing each other in a complimentary fashion. However, this disclosure is not limited thereto, and in some embodiments, the distal ends of the first and second end effectors221and223may be smooth. In other embodiments, the distal ends of the first and second end effectors221and223can have other types of protrusions, including saw-tooth, ridges, or any other surface facing each other. As discussed above, the bipolar medical instrument200may be electrically coupled to a generator that is configured to apply a voltage difference between the first and second end effectors221and223, thereby causing an electric current to flow between the first and second end effectors221and223. Thus, the first and second end effectors221and223may be formed of electrically conductive material(s). In the embodiment ofFIGS.21A-21D, the instrument comprises a single insulating member225. The insulating member225is formed between the first end effector221and the distal pulley240and is configured to electrically insulate the first end effector221from the distal pulley240. This is advantageous as both the first end effector221and the distal pulley240can be formed at least in part of a conductive material, such as a metal, which can provide other benefits such as space conservation and less wear. Thus, the first end effector221and the distal pulley240may be electrically decoupled from one another. The insulating member225may be formed of an electrically insulating material, such as, for example a material with a high dielectric strength (e.g., urethane, peek, ultem, epoxy resin, ceramic, one or more plastics, etc.). The insulating member225may be molded between the first end effector221and the distal pulley240. In some embodiments, the insulating member225may be injection molded into a pocket that is formed between the first end effector221and the distal pulley240. The insulating member225may also be designed to occupy as much area within the distal clevis205as possible to prevent stray currents from flowing between the first end effector221and other electrically charged conductors within the wrist201, thereby preventing inadvertently damaging tissue. In some embodiments, the insulating member225may occupy at least 25% of a surface defined by the outer face of the insulating member225and the distal pulley240. In other embodiments, the insulating member225may occupy 40% or more of the outer face of the insulating member225and the distal pulley240. The second end effector223may be formed as a single component with a corresponding distal pulley242(as shown inFIG.23). In some embodiments, both the second end effector223and the distal pulley242can be formed at least in part of a conductive material, such as a metal. Thus, the second end effector223and the corresponding distal pulley may be electrically coupled to one another. Due to the electrical insulation between at least the first end effector221and the distal pulley240, one or more of the distal clevis205, the proximal clevis210, the distal pulleys240, the distal axle241, the proximal pulleys245, the proximal axle245, the proximal redirect pulleys250, proximal redirect axle251, the first drive cable260, and the second drive cable265may be formed of a metal, such as, for example, tungsten, stainless steel, etc. The use of metal for one or more of the above-listed components may improve the durability of the bipolar medical instrument200as compared with the use of less wear-resistant materials. The use of metal can also increase the strength of the distal end of the bipolar medical instrument200without a corresponding increase in the overall diameter of the bipolar medical instrument200. FIGS.22A and22Billustrate a plurality of views of an embodiment of an end effector assembly in accordance with aspects of this disclosure. Specifically,FIGS.22A and22Bprovide a more detailed view of an end effector assembly222including the first end effector221, the insulating member225, and the distal pulley240ofFIGS.21A-21D.FIG.22Aillustrates the first end effector221when coupled to the distal pulley240via the insulating member225whileFIG.22Aprovides an illustration with the insulating member225absent to show the relative positions or arrangement of the first end effector221and the distal pulley240with respect to each other. The insulating member225may couple the first end effector221to the distal pulley240. In some embodiments, the insulating member225may be coupled to each of the distal pulley240and the first end effector221via a mechanical interlock including a pin270formed between the first end effector221and the distal pulley240. The pin270may be formed in the first distal pulley240and may be received in a first opening275formed in the first end effector221. The pin270may extend from a surface of the first distal pulley240and into the first opening275. A second opening or pocket280may be formed between the first end effector221and the distal pulley240. The insulating member225may be shaped to fill each of the first opening275and the second opening280to electrically insulate the first end effector221from the distal pulley240. The insulating member225may further mechanically couple the first end effector221to the distal pulley240such that forces applied to the distal pulley240via the first drive cable260are transmitted to the first end effector221. Additionally, the first electrical cable230may run through a third opening285in the distal pulley240to be electrically connected to the first end effector221. The first electrical cable230may be electrically insulated from the distal pulley240. One advantage to the mechanical interlock ofFIGS.22A and22Bincluding the pin270is that it serves as a safety feature that prevents the first end effector221from being inadvertently left behind as the bipolar medical instrument200is removed from the patient in the event that there is a connection failure of the insulating member225(e.g. resulting from damage to the insulating member225). In some circumstances, if one or more of the end effectors221,223are subjected to higher forces than under normal use, the insulating member225may break under the increased stress. If the insulating member225is broken while the bipolar medical instrument200is inside a patient's anatomy, the first opening275of the first end effector221will advantageously remain engaged with the pin270of the distal pulley240. Thus, as the bipolar medical instrument200is removed from the patient, the pin275may hold the proximal portion of the first end effector221within the distal clevis205, such that the first end effector221can be removed from the patient along with the bipolar medical instrument200. WhileFIGS.22A and22Billustrate a first end effector assembly including the first end effector221coupled to the distal pulley240,FIG.23illustrates a second end effector assembly including the second end effector223coupled to the distal pulley242. In this embodiment, the second end effector223is formed as a single component with the distal pulley242. The second end effector223is electrically connected to the second electrical cable235. Since the second end effector223is not electrically insulated from the distal pulley242, the distal pulley242and the distal axle241may all be electrically connected to the second electrical cable235. Since the distal axle241may be electrically connected to the wrist201, the wrist201may also be electrically connected to the second electrical cable235. In contrast, as the first end effector221is electrically insulated from the distal pulley240via the insulating member225, the first end effector221can be effectively electrically insulated from the wrist201and other electrically conductive components of the bipolar medical instrument200. Although not illustrated, in some embodiments, the second end effector223may be static such that the second end effector223is not configured to move with respect to the distal clevis205. The first end effector221may be configured to move relative to the second end effector223in a manner similar to the embodiment ofFIGS.21A-21D. The use of a static second end effector223may simplify the cable path design by removing the requirement for one of the DOF of movement and may also allow for a more compact design of the wrist201(e.g., by eliminating the need for a corresponding distal pulley mechanically coupled to the second end effector223). In another embodiment, the bipolar medical instrument200may not include the second electrical cable235and may instead provide a voltage potential to the second end effector223via an electrical path formed by the wrist201and/or the distal axle241. For example, the second end effector223may be electrically coupled to the corresponding distal pulley, which in turn, may be electrically coupled to the wrist201. Thus, the wrist201may be configured to provide an electric current to the second end effector223. In this embodiment, the overall size of the bipolar medical instrument may be reduced by removing the spatial and cable routing requirements for the second electrical cable235. FIGS.24A-24Cillustrate a plurality of views of another embodiment of an end effector and distal pulley assembly in accordance with aspects of this disclosure. For example, the end effector assembly300illustrated inFIGS.24A-24Cmay be used in place of the first end effector221and distal pulley240ofFIGS.21A-21D, or any other end effector and distal pulley assembly described herein. The end effector assembly300includes an end effector305, a distal pulley315, and an insulating member320. In particular,FIG.24Aillustrates the end effector assembly300with the insulating member320illustrated as transparent to show the opening or pocket310formed between the end effector305and the distal pulley315. An electrical cable230may also be electrically connected to the end effector305.FIG.24Billustrates the end effector assembly300with the insulating member320coupled between the end effector305and the distal pulley315.FIG.24Cprovides an illustration without the insulating member320to show the relative positions of the end effector305and the distal pulley315. As shown inFIGS.24A-24C, the end effector305is separate from the distal pulley315via the opening310. The end effector305and insulating member320may form a channel325into which a distal axle (e.g., the distal axle241ofFIG.21B) can be inserted. The end effector305may form a ring at the proximal end which is concentric with the channel325, and thus, with the distal axle when assembled to form a bipolar medical instrument. The insulating member320may fill the opening310to surround the ring at the proximal end of the end effector305and electrically insulate the end effector305from the distal pulley315. In comparison to the embodiment ofFIGS.22A and22B, the insulating member320of the embodiment ofFIG.24A-24Cmay occupy a larger portion of the face formed at the proximal end the end effector assembly300formed by the insulating member320and distal pulley310. In some embodiments, the insulating member320may occupy about 70% or more of the face formed at the proximal end the end effector assembly300. B. Bipolar Medical Instruments Including Dual Isolated Grips. FIG.25illustrates an embodiment of a bipolar medical instrument including dual isolated grips in accordance with aspects of this disclosure. Specifically,FIG.25illustrates a bipolar medical instrument400with a pair of end effectors415and420.FIGS.26A-26Dillustrate a plurality of views of the end effector and distal pulley assembly of the instrument inFIG.25in accordance with aspects of this disclosure. In particular,FIGS.26A-26Dillustrate side views of: a first end effector assembly411, the first end effector assembly411with the insulating member417absent, a cross-sectional view of the first end effector assembly411, and a perspective review of the first end effector assembly411with the insulating member417absent, respectively. Referring toFIG.25, the bipolar medical instrument400includes a wrist401including a distal clevis405and a proximal clevis410, a first end effector415, a first insulating member417, and a first distal pulley419, a second end effector420, a second insulating member421, and a second distal pulley423. The first end effector415, the first insulating member417, and the first distal pulley419together form a first end effector assembly411, which is illustrated inFIGS.26A-26C. Certain components of the bipolar medical instrument400are similar to those of the bipolar medical instrument200illustrated inFIGS.21A-21D, and thus, may function in a similar fashion to the previous description thereof. In the embodiment ofFIG.25, each of the first and second end effectors415and420is electrically insulated from the wrist401by the first and second insulating members417and421, respectively. Thus, each of the first and second end effectors415and420may be electrically connected to a separate electrical cable such that a voltage difference can be applied to the first and second end effectors415and420. Each of the first and second end effectors415and420may have a substantially similar construction, and thus the first end effector assembly411will be described in connection withFIGS.26A-26C. The first end effector415may be separated from the first distal pulley419by the first insulating member417. A proximal portion of the first end effector415may overlap a distal portion of the first distal pulley419along a longitudinal axis and transverse axis of the first end effector415to form a tortuous void425between the first end effector415and the first distal pulley419. The first insulating member417may be shaped to fill the tortuous void425, thereby mechanically coupling the first distal pulley419to the first end effector415such that forces applied to the first distal pulley419are transmitted to the first end effector415. As shown inFIG.26B, the tortuous void425may be S-shaped when viewed from the side. Additionally, the tortuous void425may include channels formed in each of the protrusions forming the S-shape on the distal end of the first distal pulley419and the proximal end of the first end effector415as shown inFIG.26D. The first end effector415may further include a receptacle425for an electrical cable to receive a voltage from a generator via the electrical cable. The insulating member417, which is formed through the tortuous void, can be applied to any of the embodiments described herein. FIGS.27A and27Billustrate yet another embodiment of a bipolar medical instrument including dual isolated grips in accordance with aspects of this disclosure. The bipolar medical instrument500may include: a wrist501; a first end effector assembly505including a first end effector507, a first insulating member509, and a first distal pulley511; and a second end effector assembly515including a second end effector517, a second insulating member519, and a second distal pulley521. Similar to the embodiment ofFIG.25, in the bipolar medical instrument500ofFIGS.27A and27B, each of a first end effector507and a second end effector517may be electrically insulated from the wrist501. Further, the design of each of the first end effector assembly505and the second end effector assembly515is similar to that of the end effector assembly222ofFIGS.22A and22B. In addition, the bipolar medical instrument500of the embodiment ofFIGS.27A and27Bmay employ pulley sharing where each of the first cable segments shares one of the proximal pulleys and one of the proximal redirect pulleys with one of the second cable segments. Further, the electrical cable in the embodiment of embodimentFIGS.27A and27Bmay be routed through a center of the wrist such that only one electrical cable is present in the wrist. In other embodiments, a pair of electrical cables can be present in the wrist. The embodiments inFIGS.21A-24C(e.g., single isolated grip embodiments) andFIGS.25-27B(e.g., dual isolated grip embodiments) are particularly useful for insulation when the distal pulleys that are coupled to the grips are formed of a conductive material such as metal. As an alternative to embodiments wherein the distal pulleys are formed of metal, it is possible for at least one distal pulley to be formed of a non-conductive material of a high dielectric strength. In some embodiments, the one or more non-conductive distal pulleys can then be used with or without the insulative skirts. Such embodiments are described below inFIGS.28-29B. C. Bipolar Medical Instruments Including One or More Non-Conductive Pulleys. FIG.28illustrates yet another embodiment of a bipolar medical instrument in accordance with aspects of this disclosure. Specifically,FIG.28illustrates a bipolar medical instrument600having a wrist601, a first end effector assembly610including a first end effector611, and a second end effector assembly620including a second end effector621. In the embodiment ofFIG.28, the first end effector611may be electrically insulated from portions of the wrist601via a distal pulley that is formed of a non-conductive material, while the second end effector assembly620may not be electrically insulated from the wrist601. In particular, in some embodiments, the second end effector assembly620may be electrically connected to the wrist601and may receive a voltage potential via the wrist601forming a portion of the electrical path. FIG.29Aillustrates an embodiment of a first end effector assembly610in accordance with aspects of this disclosure andFIG.29Billustrates an embodiment of a second end effector assembly620in accordance with aspects of this disclosure. As shown inFIG.29A, the first end effector assembly610includes the first end effector611and a first distal pulley613. In more detail, the first distal pulley613may be formed of an electrically insulating material with a high dielectric strength (e.g., urethane, peek, ultem, epoxy resin, ceramic, one or more plastics, etc.). Since the distal pulley613is formed of an electrically insulating material, the first end effector611is electrically insulated from portions of the wrist601. In other embodiments, the first end effector assembly610further includes an insulating member (not illustrated) coupled between the first end effector611and the distal pulley613, where each of the insulating member and the distal pulley613is formed of an electrically insulating material. With reference toFIG.29B, the second end effector assembly620may be similar to the second end effector223ofFIG.23. For example, the second end effector621and the second distal pulley623may be formed as a single component or may be formed of two separate components with are electrically connected to each other. D. Example Method for Actuating an End Effector in Multiple Degrees of Movement. FIG.30is a flowchart illustrating an example method operable by a robotic system, or component(s) thereof, for actuating an end effector in multiple degrees of movement in accordance with aspects of this disclosure. For example, the steps of method700illustrated inFIG.30may be performed by processor(s) and/or other component(s) of a medical robotic system (e.g., robotically-enabled system10) or associated system(s). For convenience, the method700is described as performed by the “system” in connection with the description of the method700. The method700begins at block701. At block705, the system may advance or retract a first set of one or more cable segments engaged with a first distal pulley. The instrument may be implemented as shown inFIGS.21A-21D,FIG.25,FIG.27, orFIG.28, and include the first distal pulley coupled to a first end effector and configured to actuate the first end effector in a first degree of movement. The first end effector may be electrically insulated from the first distal pulley via a first insulating member. At block710, the system may advance or retract a second set of one or more cable segments engaged with a second distal pulley. The second distal pulley may be coupled to a second end effector and configured to actuate the second end effector in a second degree of movement. In certain implementations, the method700may further include the system advancing or retracting the first set of one or more cable segments and the second set of one or more cable segments to rotate the first end effector and the second end effector in a third degree of movement. The first set of one or more cable segments and the second set of one or more cable segments may be engaged with a first proximal pulley and a second proximal pulley, respectively. In some embodiments, the steps in blocks705and710can be performed sequentially, while in other embodiments, the steps in blocks705and710can be performed in concert. The method700ends at block715. E. Example Method for Manufacturing a Bipolar Medical Instrument. FIG.31is a flowchart illustrating an example method for manufacturing a bipolar medical instrument in accordance with aspects of this disclosure. The bipolar medical instrument manufactured according to the method800may be implemented as shown inFIGS.21A-21D,FIG.25,FIG.27, orFIG.28. The method800begins at block801. At block805, the method800includes providing an instrument including: a first end effector and a first set of one or more distal pulleys. At block810, the method800includes molding a first insulating member between the first end effector and the first set of distal pulleys. The first insulating member electrically isolates the first end effector from the first set of one or more distal pulleys. In certain implementations, molding the first insulating member includes insert molding. The method800ends at block815. In some embodiments, the assembly including the first end effector, the first set of distal pulleys and the first insulating member can then be coupled to an instrument wrist. In other embodiments, the first set of distal pulleys can already be coupled to an instrument wrist before insert molding the first insulating member. 3. Implementing Systems and Terminology. Implementations disclosed herein provide systems, methods and apparatus for an articulating medical instrument which may include a bipolar end effector. It should be noted that the terms “couple,” “coupling,” “coupled” or other variations of the word couple as used herein may indicate either an indirect connection or a direct connection. For example, if a first component is “coupled” to a second component, the first component may be either indirectly connected to the second component via another component or directly connected to the second component. The functions associated with the articulating medical instrument described herein may be stored as one or more instructions on a processor-readable or computer-readable medium. The term “computer-readable medium” refers to any available medium that can be accessed by a computer or processor. By way of example, and not limitation, such a medium may comprise random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory, compact disc read-only memory (CD-ROM) or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer. It should be noted that a computer-readable medium may be tangible and non-transitory. As used herein, the term “code” may refer to software, instructions, code or data that is/are executable by a computing device or processor. The methods disclosed herein comprise one or more steps or actions for achieving the described method. The method steps and/or actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is required for proper operation of the method that is being described, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims. As used herein, the term “plurality” denotes two or more. For example, a plurality of components indicates two or more components. The term “determining” encompasses a wide variety of actions and, therefore, “determining” can include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, a database or another data structure), ascertaining and the like. Also, “determining” can include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory) and the like. Also, “determining” can include resolving, selecting, choosing, establishing and the like. The phrase “based on” does not mean “based only on,” unless expressly specified otherwise. In other words, the phrase “based on” describes both “based only on” and “based at least on.” The previous description of the disclosed implementations is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these implementations will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other implementations without departing from the scope of the invention. For example, it will be appreciated that one of ordinary skill in the art will be able to employ a number corresponding alternative and equivalent structural details, such as equivalent ways of fastening, mounting, coupling, or engaging tool components, equivalent mechanisms for producing particular actuation motions, and equivalent mechanisms for delivering electrical energy. Thus, the present invention is not intended to be limited to the implementations shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

11857280

DETAILED DESCRIPTION This description and the accompanying drawings that illustrate inventive aspects, embodiments, implementations, or applications should not be taken as limiting—the claims define the protected invention. Various mechanical, compositional, structural, electrical, and operational changes may be made without departing from the spirit and scope of this description and the claims. In some instances, well-known circuits, structures, or techniques have not been shown or described in detail in order not to obscure the invention. Like numbers in two or more figures represent the same or similar elements. Further, specific words chosen to describe one or more embodiments and optional elements or features are not intended to limit the invention. For example, spatially relative terms—such as “beneath”, “below”, “lower”, “above”, “upper”, “proximal”, “distal”, and the like—may be used to describe one element's or feature's relationship to another element or feature as illustrated in the figures. These spatially relative terms are intended to encompass different positions (i.e., translational placements) and orientations (i.e., rotational placements) of a device in use or operation in addition to the position and orientation shown in the figures. For example, if a device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be “above” or “over” the other elements or features. Thus, the exemplary term “below” can encompass both positions and orientations of above and below. A device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Likewise, descriptions of movement along (translation) and around (rotation) various axes includes various special device positions and orientations. The combination of a body's position and orientation define the body's “pose.” Similarly, geometric terms, such as “parallel”, “perpendicular”, “round”, or “square”, are not intended to require absolute mathematical precision, unless the context indicates otherwise. Instead, such geometric terms allow for variations due to manufacturing or equivalent functions. For example, if an element is described as “round” or “generally round”, a component that is not precisely circular (e.g., one that is slightly oblong or is a many-sided polygon) is still encompassed by this description. The words “including” or “having” mean including but not limited to. It should be understood that although this description is made to be sufficiently clear, concise, and exact, scrupulous and exhaustive linguistic precision is not always possible or desirable. For example, considering a video signal, a skilled reader will understand that an oscilloscope described as displaying the signal does not display the signal itself but a representation of the signal, and that a video monitor described as displaying a signal does not display the signal itself but the video information the signal carries. In addition, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context indicates otherwise. And, the terms “comprises”, “includes”, “has”, and the like specify the presence of stated features, steps, operations, elements, and/or components but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups. And, the or each of the one or more individual listed items should be considered optional unless otherwise stated, so that various combinations of items are described without an exhaustive list of each possible combination. The auxiliary verb may likewise imply that a feature, step, operation, element, or component is optional. Elements described in detail with reference to one embodiment, implementation, or application optionally may be included, whenever practical, in other embodiments, implementations, or applications in which they are not specifically shown or described. For example, if an element is described in detail with reference to one embodiment and is not described with reference to a second embodiment, the element may nevertheless be claimed as included in the second embodiment. Thus, to avoid unnecessary repetition in the following description, one or more elements shown and described in association with one embodiment, implementation, or application may be incorporated into other embodiments, implementations, or aspects unless specifically described otherwise, unless the one or more elements would make an embodiment or implementation non-functional, or unless two or more of the elements provide conflicting functions. Elements described as coupled (e.g., mechanically, electrically, in communication, and the like) may be directly coupled, or they may be indirectly coupled via one or more intermediate components unless otherwise specified. Inventive aspects are described in part in terms of an implementation using a da Vinci® Surgical System, commercialized by Intuitive Surgical, Inc. of Sunnyvale, California Examples of such surgical systems are the da Vinci X® Surgical System (Model IS4200), the da Vinci Xi® Surgical System (Model IS4000), and the da Vinci Si® Surgical System (Model IS3000). Knowledgeable persons will understand, however, that inventive aspects disclosed herein may be embodied and implemented in various ways, including computer-assisted and hybrid combinations of manual and computer-assisted embodiments and implementations. Implementations on da Vinci® Surgical Systems are merely exemplary and are not to be considered as limiting the scope of the inventive aspects. For example, the techniques disclosed apply to medical and non-medical procedures, and to medical and non-medical tools (e.g., manipulation tools or cameras). For example, the tools (e.g., manipulation tools or cameras), systems, and methods of any of the embodiments described herein may be used for non-medical purposes including industrial uses, general robotic uses, and sensing or manipulating non-tissue work pieces. Other example applications involve cosmetic improvements, imaging of human or animal anatomy, gathering data from human or animal anatomy, setting up or taking down the system, and training medical or non-medical personnel. Additional example applications include use for procedures on tissue removed from human or animal anatomies (without return to a human or animal anatomy), and performing procedures on human or animal cadavers. Further, these techniques can also be used for medical treatment or diagnosis procedures that do, or do not, include surgical aspects. Persons of skill in the art will understand that a computer is a machine that follows programmed instructions to perform mathematical or logical functions on input information to produce processed output information. A computer includes a logical calculation unit that performs the mathematical or logical functions, and a memory system that stores the programmed instructions, the input information, and the output information. The term “computer” and similar terms, such as “processor” or “controller” or “control system”, should be considered synonymous. Persons of skill in the art will understand that a computer's function may be centralized or distributed among two or more locations, and it may be implemented in various combinations of hardware, firmware, and software. Teleoperated medical systems have been developed that increase an operator's dexterity or ability, to improve ergonomics, etc. For example, minimally invasive teleoperated surgical systems that operate at least in part with computer assistance (“telesurgical systems”) have been developed and operate using a master/slave model in which a user-operated master input device controls a motor-driven slave surgical tool. The user grasps and moves the master input device to operate a slave surgical tool by remote control, rather than directly holding and moving the tool by hand. The slave surgical tool follows the motion of the master input device. During minimally invasive telesurgery, an imaging device such as an endoscopic camera at the surgical site captures a moving image of tissue and a slave surgical tool's working end. For convenience, “camera” is used herein to refer generally to imaging devices used to capture one or more images. Examples of image devices include those based on optical, ultrasound technology, magnetic resonance imaging (MRI), CT (computed tomography), X-ray, etc. Examples of endoscopic cameras include monoscopic, stereoscopic, and 3D cameras, as well as cameras that image inside the visible spectrum, in the infrared, in the ultraviolet, some other part of the spectrum, or a combination of the foregoing. “Tool” is used herein to include imaging and non-imaging instruments. The term “end effector” as used herein refers to any distal end component or portion of a tool, such as a tip of a manipulation, suction, irrigation, or cautery tool or a tip of an imaging device such as an endoscopic camera (e.g., examples of end effectors include a grasper, scissors, a cautery hook, a suction/irrigation nozzle, a blunt tip, a distal tip of a catheter or other flexible device, lenses for an optical imaging device, a probe tip for an ultrasonic imaging device, etc.). The user views the image while operating the master device and sees the slave end effector movement that corresponds to the master device movement. A computer control system provides the control interface between the master device and the slave surgical tool. The user typically operates the master device from a position that is remote from the patient (e.g., across the operating room, in a different room, or in a completely different building from the patient). In many telesurgical situations, the user is outside the sterile field and so does not directly interact with the patient. In some telesurgical situations, however, the user operating a master device is close enough to the patient to directly interact with the patient, optionally within the sterile field. The master device is typically free to move in all six Cartesian degrees of freedom (DOFs), so that changes in master device position (translations along the Cartesian axes) and changes in master device orientation (rotations around the Cartesian axes) result in corresponding slave tool translations and rotations. This description is in the context of Cartesian reference frames, and persons of skill in the art will understand that other suitable three-dimensional reference systems (e.g., cylindrical, spherical) may be used. The master device may be in various forms. For example, the master device may be the distal-most link in a kinematic chain with redundant mechanical DOFs, a joy-stick, an exoskeletal glove, or the like. In some instances the master device tracks hand gestures, so that the user's hand alone, or part of the user's hand, functions as a virtual master device if the hand's translations and rotations are tracked with sufficient accuracy for surgery. Master devices may optionally have one or more mechanical DOFs to control corresponding end effector mechanical DOFs, such as a pincer mechanism for end effector jaw grip, or a switch (e.g., push button or slider) for end effector knife movement between jaws. And, master devices may optionally have one or more inputs such as switches to control additional end effector or surgical system features, such as electrosurgical energy application, stapler control, engaging and disengaging the master/slave control relationship between the master device and the slave tool (“clutching”), changing system operating modes, changing master device control from one slave surgical tool to a second slave surgical tool, display menu selection, and the like. Surgical tools are in various forms, and they include tools for both therapeutic and diagnostic functions. Example surgical tools include tissue graspers, needle drivers, scissors, retractors, electrosurgical cautery tools, staplers, surgical clip appliers, ultrasonic cutters, suction/irrigation tools, catheters, ultrasound probes, etc. In some situations a camera, such as an endoscopic camera or other image capture technology, may be considered a surgical tool. Cameras and associated image processing technology may be used for specialized functions, such as near infra-red image capture, fluorescent energy capture, hyperspectral imaging, and the like. These special imaging functions increase the effectiveness of an intervention. Many telesurgical systems incorporate robotic technology (they are often referred to as “surgical robots” even though they may undertake no autonomous action). Example telesurgical systems are illustrated in U.S. Pat. No. 6,331,181 B1 (filed Oct. 15, 1999)(describing a multi-port system in which a camera and other surgical tools enter the body via separate ports), U.S. Pat. No. 8,784,435 B2 (filed Aug. 12, 2010)(describing a single-port system in which a camera and other surgical tools enter the body via a single common port), and U.S. Pat. No. 8,801,661 B2 (filed Nov. 7, 2013)(describing a system that uses a flexible surgical tool). The full disclosures of U.S. Pat. Nos. 6,331,181, 8,784,435, and 8,801,661 are incorporated herein by reference in their entireties. Telesurgical systems typically include one or more motor-driven teleoperated manipulators. A surgical tool is removably mounted on a manipulator, and the manipulator typically moves both the tool as a whole and component parts of the tool, including the tool's end effector. The manipulator's movements correspond to the user's master device movements so that the end effector movements precisely follow the master device movements. Various telesurgical manipulator architectures are known, such as serial kinematic chains, spherical linkages, orthogonal prismatic joints (both linear and circular curvilinear), and the like. The surgical tool itself may be a single rigid body or a kinematic chain, and so the tool's kinematic pose determines its end effector's pose in space. Likewise, the manipulator's kinematic pose determines the surgical tool's pose in space. The manipulator is typically held in a fixed position and orientation by a non-teleoperated setup structure, such as a kinematic arm. The setup structure typically includes at least one kinematic pair of links coupled by a movable and lockable joint, so that the manipulator may be repositioned in space and then held in the new pose. The lockable joint(s) may be powered (motorized) or unpowered. And the lockable joint(s) may be locked in various ways, such as by using manually or electrically controlled brakes, or by controlling a powered joint to maintain a fixed relationship between links in a kinematic pair. The setup structure's kinematic pose determines the manipulator's pose in space by holding the manipulator's proximal-most (“base”) link stationary. In turn, the setup structure may have a proximal-most link (“base”) optionally fixed to a mechanical ground (e.g., floor, wall, ceiling, or structure fixed to floor, wall, or ceiling) or optionally movable with reference to a mechanical ground (e.g., a cart that rolls on the floor, moves along one or more rails on a wall, ceiling, or operating table, etc.). A movable setup structure base also functions to pose the manipulator in space. The manipulator, the optional setup structure (fixed or movable), and the optional base (fixed or movable) function together as a support structure for the surgical tool mounted on the manipulator with reference to the mechanical ground. Any structure that holds a manipulator, an imaging device such as a camera, or another tool fixed in space with reference to a mechanical ground may function as a support structure. For example, a motorized or no-motorized fixture holding an endoscopic camera steady in space may function as camera support structure as the camera captures images of the surgical site. As another example, an endoscopic camera may be held in place by support structure comprising a kinematic chain; the kinematic chain may be a passive kinematic chain, or include one or more driven joints. Additional examples of mechanical support structures are described below. FIG.1is a diagrammatic plan view that shows components of an exemplary teleoperated system, specifically a multi-port telesurgical system100for performing minimally invasive surgery. System100is similar to that described in more detail in U.S. Pat. No. 6,246,200 B1 (filed Aug. 3, 1999) (disclosing “Manipulator Positioning Linkage for Robotic Surgery), the full disclosure of which is incorporated herein by reference. Further related details are described in U.S. Pat. No. 8,529,582 B2 (filed May 20, 2011) (disclosing “Instrument Interface of a Robotic Surgical System”) and U.S. Pat. No. 8,823,308 B2 (filed Jul. 1, 2011) (disclosing “Software Center and Highly Configurable Robotic Systems for Surgery and Other Uses”), the full disclosures of which are likewise incorporated herein by reference. A system user102(typically a surgeon or other skilled clinician when system100is used for surgery) performs a minimally invasive surgical procedure on a patient104lying on an operating table106. The system user102sees moving images (monoscopic (2D) or stereoscopic (3D)) presented by display108and manipulates one or more master devices110at a user's control unit112. In response to the user's master device movements, a computer113acts as a specialized control system and directs movement of slave teleoperated tools114(the tool114being a surgical tool in this surgical example). As described in more detail below, master devices110are computationally aligned with tools114. Based on this alignment, computer113generates commands that correlate the movement of the master devices and the end effectors of tools114so that the motions of the end effectors follow the movements of the master devices in the hands of the system user102in a way that is intuitive to the user. As described above, computer113typically includes data processing hardware and machine-readable code that embodies software programming instructions to implement methods described herein (e.g., including related control systems). And although computer113is shown as a single block in the simplified diagram ofFIG.1, the computer may comprise two or more centralized or distributed data processing units, with at least a portion of the processing optionally being performed adjacent an input device, a portion being performed adjacent a manipulator, and the like. Any of a wide variety of centralized or distributed data processing architectures may be employed. Similarly, the programming code may be implemented as a number of separate programs or subroutines, or it may be integrated into various other telesurgical system components. As shown inFIG.1, system100further includes a manipulator assembly116, which includes two teleoperated manipulators120for tools114and teleoperated manipulator124for a tool that comprises an imaging device. For convenience of explanation, the imaging device is shown and described below as a camera126, and camera126may be any appropriate imaging device. For example, camera126may be configured to image optically, ultrasonically, or using any other appropriate technology. In this surgical example, camera126is an endoscopic camera configured to image in the visible spectrum. Other numbers and combinations of manipulators are optional (e.g., one, three, or more manipulators for tools, two or more manipulators for cameras). Manipulator assembly116also includes manipulator setup structures118that support manipulators120during the procedure. And, manipulator assembly116includes an imaging device setup structure shown as a camera setup structure122; camera setup structure supports manipulator124. The tool setup structures and the camera setup structure each have a base link, and these base links are coupled to a single movable cart. For each tool114and for camera126, the associated manipulator, setup structure, and cart illustrate a support structure for the tool or camera. As shown, the image of the internal surgical site is displayed to user102by a display108in user's control unit112. The internal surgical site is optionally simultaneously shown to assistant128by an auxiliary display130(2D or 3D). As mentioned above and described in more detail below, however, in some teleoperated systems user102may be close to patient104during surgery (e.g., in a position similar to assistant128's position as shown). In these telesurgical system architectures the user may view the image of the surgical site on a 2D or 3D display mounted on the floor, wall, ceiling, or other equipment, as illustrated by display130's position. Sterile assistant128(e.g., a nurse, an assisting surgeon, or another skilled clinician) performs various optional tasks before, during, and after surgery. For example, assistant128may adjust the poses of manipulators120,124, adjust setup structures118,122, swap tools114with other tools132on a manipulator, operate non-teleoperated medical tools and equipment within the patient, hold an endoscopic camera, and perform other tasks related to teleoperated surgery and surgery in general. FIG.2is a front view that illustrates a manipulator assembly116. Specifically,FIG.2shows a telesurgical system patient-side unit that illustrates an embodiment of a multi-port telesurgical manipulator assembly, which is commercialized as a da Vinci® Surgical System by Intuitive Surgical, Inc. of Sunnyvale, California, U.S.A. In a multi-port telesurgical system, tools enter the body through two or more separate incisions or natural orifices. In this example, manipulator assembly116includes four teleoperated surgical tool and camera manipulators supported by a movable patient-side unit. In other embodiments of a multi-port telesurgical system, one or more of the manipulators120,124and associated setup structures118,122are individually or in combination mounted on one or more separate movable units or are fixed to a mechanical ground as described herein. It can be seen that various combinations of manipulators and their associated support structures may be used. In a single-port telesurgical system, all tools enter the body through a single incision or natural orifice. Examples of manipulator assemblies for single port telesurgical systems are shown and described in U.S. Pat. No. 8,784,435 B2 (filed Aug. 12, 2010) (disclosing “Surgical System Entry Guide”), and examples of telesurgical systems and flexible surgical tools are shown and described in U.S. Pat. No. 8,801,661 B2 (filed Nov. 7, 2013) (disclosing “Robotic Catheter System and Methods”). In accordance with an aspect of the invention, one or more master devices as described herein may be used to control two or more different telesurgical system configurations, be they two or more different multi-port systems, two or more multi-port, single-port systems, two or more flexible tool systems, or any combination of such multi-port, single-port, and flexible tool systems. FIG.3is a perspective view of a teleoperated tool114that may be used with a teleoperated system. Specifically, a teleoperated surgical tool is shown; this surgical tool that includes a distal end effector140, an optional wrist141, a proximal end chassis142, a housing143over chassis142(chassis142and housing143may optionally be combined), and an elongate shaft144coupled between end effector140and chassis142. End effector140is coupled to shaft144either directly or via optional wrist141. Various wrist141architectures allow end effector140's orientation to change with reference to shaft144in various combinations of pitch, yaw, and roll. Optionally, the end effector roll function is carried out by rolling shaft144. Various mechanisms (combinations of pulleys, cables, levers, gears, gimbals, motors, etc.) are mounted on chassis142and function to receive either mechanical or electrical inputs from tool114's associated manipulator. These inputs are used to orient and operate end effector140. Chassis142will typically include a mechanical or electrical interface146adapted for coupling to a manipulator120,124. As described in more detail in U.S. Pat. No. 6,331,181 B1, tool114will often include a memory148, with the memory typically being electrically coupled to a data interface (the data interface typically forming a portion of interface146). This data interface allows data communication between memory148and computer113(seeFIG.1) when the tool is mounted on the manipulator. End effector140is also illustrative of an endoscopic camera-type tool with an image capture component at an appropriate location (such as the camera-type tool's proximal end or distal end), and either with or without wrist141. And so, tool114by its structure also illustrates camera126for kinematic purposes, and subsequent reference to kinematic properties of, and control aspects associated with, tool114and its analogs apply as well to camera126and its analogs. A variety of alternative teleoperated surgical tools of different types and differing end effectors140may be used. The tools associated with at least some of the manipulators are configured to be removed from their associated manipulator and replaced with an alternate tool during a surgical procedure. Additional details are provided in U.S. Pat. No. 8,823,308 B2. In some operational environments, tools114and end effectors140optionally can be combined into combinations with multiple capabilities. Additional details related to these combinations are provided in U.S. Pat. No. 7,725,214 B2 (filed Jun. 13, 2007) (disclosing “Minimally Invasive Surgical System”), the disclosure of which is incorporated herein by reference in its entirety. Details related to interfaces between the tools114and the manipulators120are provided in U.S. Pat. No. 7,955,322 B2 (filed Dec. 20, 2006) (disclosing “Wireless Communication in a Robotic Surgical System”) and U.S. Pat. No. 8,666,544 B2 (filed Jul. 10, 2013)(disclosing “Cooperative Minimally Invasive Telesurgical System”), the disclosures of which are incorporated herein by reference in their entireties, and also in U.S. Pat. No. 8,529,582 B2. FIG.4is a front elevation view of a user control unit that shows an example of user control unit112ofFIG.1. The user control unit112includes a display108where an image of a work site (e.g. a surgical site in a surgical example) is displayed to a user102(e.g., a surgeon or other skilled clinician in the surgical example). A support111is provided on which the user102can rest the forearms while gripping two master devices110, one in each hand. The master devices110are positioned in a space behind support111and generally below and behind display108. When using control unit112, the user102typically sits in front of control unit112, positions the eyes in front of display108, and grips the master devices110, one in each hand, while resting the forearms on support111. The master devices are positioned so that images of the associated end effectors are between the master devices and the eyes, so that motion of the master devices intuitively moves the masters as the user sees the end effectors in place of the hands. The user control unit112optionally may include the computer113, or a portion of the computer113, that functions to establish and maintain a teleoperated control relationship between the master devices110and the associated tools114and their end effectors140. An effective teleoperated control relationship between a master device and its slave tool (e.g. a slave surgical tool in the surgical example) and end effector requires a spatial alignment between the master device and the end effector. The alignment must provide a reasonably accurate relationship between the user's perceived motion of the master device (e.g., a proprioceptive sense) and the user's perceived resulting motion of the end effector (e.g., a visual sense). For example, if the user moves a hand grasping a master device to the left, the user expects to perceive the associated slave manipulator move to the left. If the perceived spatial motions match, then the user can easily control the slave's movement by moving the master device. But if the perceived spatial motions do not match (e.g., a master device movement to the left results in a slave movement up and to the right), then slave control is difficult. The required alignment is done using known kinematic relationships and reference frame transforms in the teleoperated system (e.g. a telesurgical system in the surgical example). These relationships are described below in Cartesian terms, although other 3-dimensional coordinate systems may be used for systems that function in 3-dimensional space. 1. Architectures and Reference Frames FIG.5Ais a schematic view of teleoperated system components (e.g. telesurgical system components in surgical examples) and associated Cartesian reference frames. As shown inFIG.5A, camera126(e.g. an endoscopic camera in endoscopic surgery examples) has a field of view (FOV)127. A distal portion of tool114(e.g. a surgical tool in surgical examples) with a wrist141and end effector140, where its wrist141and its end effector140are within FOV127. End effector reference frame150is associated with end effector140, and tool reference frame151is associated with a proximal portion—the main body—of tool114, such as the portion outside the patient (chassis, housing, proximal shaft, etc.). If the tool does not have a wrist141, then reference frames150and151may be combined into a single reference frame sufficient to position and orient both the proximal portion and the end effector140of the tool114, or the reference frames150,151may be kept separate, each having an origin at a different position. Similarly, field of view reference frame152is associated with FOV127, and imaging device reference frame153is associated with a body portion of camera126, such as the proximal portion outside the patient. If camera126does not have a wrist141, then reference frames152and153may be combined into a single reference frame, or they may be kept separate, each having an origin at a different position. For systems in which the physical dimensions of all tools114(e.g. surgical tools in surgical examples) including camera126, and mechanical links are known, and in which all joint angles between these mechanical links can be determined (using direct rotation sensors, motor position sensors, optical fiber shape sensors, and the like), the kinematic relationship between reference frame150or151and a reference frame of any other link in tool114can be determined by using well-known kinematic calculations. Likewise, the kinematic relationship between reference frame152or153and any other link in camera126can be determined. And so, for such systems in which end effector140operates within FOV127, an alignment between reference frames150and152will allow the user to easily control end effector140in FOV127. FIG.5Afurther shows user102viewing display108and grasping master device110. Display108displays the images within FOV127. As shown, an image140aof end effector140is displayed on display108. A display reference frame154is associated with display108, and a master device reference frame156is associated with master device110. As master device110is translated and rotated in 3D space, its associated reference frame156translates and rotates correspondingly. These reference frame156translations and rotations (pose changes) can be sensed using known methods, and they are mathematically transformed to end effector140's reference frame150to provide a control relationship between master device110and end effector140by using well-known kinematic calculations. As master device110's frame156position and orientation is changed, end effector140's reference frame150position and orientation is changed correspondingly, so that end effector140's movement is slaved to master device110's movement and follows master device110's movement. User102views end effector140's position and orientation changes on display108. In order to establish the desired easy and intuitive control relationship between master device movement and end effector image movement, relationships are established between reference frames150and152, and between reference frames154and156. Once these reference frame relationships are established, movement of reference frame150with respect to reference frame152can be controlled to exactly or acceptably match movement of reference frame156with respect to reference frame154. FIG.5Bis another schematic view of teleoperated system components and associated Cartesian reference frames.FIG.5Billustrates the various components shown inFIG.5Asupported by mechanical support structures with reference to mechanical ground.FIG.5Balso illustrates reference frames associated with these support structures. For simplicity in this and the following figures, each support structure is depicted as a kinematic pair—two links coupled by a movable joint. It should be understood, however, that the support structures may be various optional configurations, such as a single link with zero DOF, a single kinematic pair with 1 or more DOFs, or combinations of kinematic pairs with 2 or more DOFs. And, support structures with 2 or more DOFs may optionally have joints that give the support structure redundant DOFs. Any of various kinematic joints (rotational as shown, prismatic, spherical, etc.) may be used. As shown inFIG.5B, master device110is supported by master device support structure160that begins at a mechanically grounded portion160a(also called “base160a”) and extends distally until coupled with master device110. Reference frame161is associated with one link of master device support structure160. Similarly, display108is supported by display device support structure162that begins at a mechanically grounded base162aand extends distally until coupled with display108. Reference frame163is associated with one link of display device support structure162. Similarly, camera126is supported by an imaging device support structure (shown as camera support structure164) that begins at a mechanically grounded base164aand extends distally until coupled with camera126. Camera support structure reference frame165is associated with one link of camera support structure164. And similarly, tool114is supported by tool support structure166that begins at a mechanically grounded base166aand extends distally until coupled with tool114. Reference frame167is associated with one link of tool support structure166. FIG.5Balso shows that master device support structure160may optionally be configured as a support structure when there is a break in the kinematic chain between master device110aand the grounded portion160aof the master device support structure. This configuration exists when master device110is not mechanically grounded (i.e., master device110ais an “ungrounded” master device). For communication to or from master device110a, tether that includes a communication line or a wireless connection may be used. It will be recalled that the master device may be the user102's unaugmented hand or hands, and so spatial sensing of the hand pose is a wireless implementation of an ungrounded master. Control commands160bfrom master device110—position and orientation changes with reference to the master device reference frame156and any additional control inputs (buttons, levers, finger movements, hand poses, etc.) from the master device itself—are received via master device control input receiver160cvia the tether, via a wireless signal from the master device, or by free space pose sensing. The control commands are then routed to computer113for processing and corresponding slave control actions. Examples of ungrounded master devices are given in U.S. Pat. No. 8,521,331 B2 (filed Nov. 13, 2009)(disclosing “Patient-side Surgeon Interface for a Minimally Invasive, Teleoperated Surgical Instrument”), U.S. Pat. No. 8,935,003 B2 (filed Sep. 21, 2010)(disclosing “Method and System for Hand Presence Detection in a Minimally Invasive Surgical System”), and U.S. Pat. No. 8,996,173 B2 (filed Sep. 21, 2010)(disclosing “Method and Apparatus for Hand Gesture Control in a Minimally Invasive Surgical System”), which are incorporated herein by reference. When joint positions are determined, well-known forward or inverse kinematic calculations are used to transform between master device reference frame156and master device support structure reference frame161; between display reference frame154and display support structure reference frame163; between the imaging device field-of-view reference frame (referred to as the camera FOV reference frame152), the imaging device reference frame (camera reference frame153), and the imaging device support structure reference frame (camera support structure reference frame165); and between end effector reference frame150, tool reference frame151, and tool support structure reference frame167. See e.g., U.S. Pat. No. 5,631,973 (filed May 5, 1994) (disclosing “Method for Telemanipulation with Telepresence”), U.S. Pat. No. 5,808,665 (filed Sep. 9, 1996)(disclosing “Endoscopic Surgical Instrument and Method for Use”), and U.S. Pat. No. 6,424,885 B1 (filed Aug. 13, 1999)(disclosing “Camera Referenced Control in a Minimally Invasive Surgical Apparatus”), the disclosures of which are incorporated herein by reference in their entireties. FIG.5Bfurther shows a world reference frame168that is stationary with respect to the depicted mechanical grounds. Reference frame168may be directly associated with the mechanical grounds, or it may be associated with some other structure that remains stationary with respect to the mechanical grounds. And, gravity vector (g)169is illustrated with reference to world reference frame168, arbitrarily aligned with frame168's z-axis, although it should be understood that world reference frame may optionally be at any orientation in relation to the gravity vector. Magnetic north is another example of a reference axis that can be associated with a stationary world reference frame. FIG.5Cis another schematic view of teleoperated system components and associated Cartesian reference frames.FIG.5Cillustrates that support structures for the system components may optionally be combined in various ways, and reference frames may be associated with the combined support structures. For example, the master device support structure160and the display device support structure162may be combined into a common control support structure170as shown. Control support structure170extends from a proximal base170aat a mechanical ground and then branches distally to support display108and master device110. An example of such a control support structure common to both a master device and a display is user control unit112shown inFIG.4. Control support structure170may also be configured to support ungrounded master device110aconfigurations, as described above and as shown inFIG.5C. A control support structure reference frame171is associated with control support structure170. Well-known forward or inverse kinematic calculations are used to transform between display reference frame154, master device reference frame156, and control support reference frame171. And, control support reference frame171may be used in ungrounded master configurations as shown. As another example that illustrates how support structures may optionally be combined,FIG.5Cshows camera support structure164and tool support structure166combined into a single device support structure172(e.g. a surgical device support structure in surgical examples). Device support structure172extends from a proximal base172aat a mechanical ground and then branches distally to support tool114and camera126. An example of such a device support structure is manipulator assembly116shown inFIG.2. A device support reference frame173is associated with device support structure172. Well-known forward or inverse kinematic calculations are used to transform between end effector reference frame150, tool reference frame151, FOV reference frame152, camera reference frame153, and device support reference frame173as necessary. It will be recalled that in some cases a person may hold camera126and so act as a camera support structure. FIG.5Calso shows world reference frame168and gravity vector (g)169in relation to control support structure170and device support structure172, and also in relation to their associated reference frames. World reference frame168and gravity vector169are shown to illustrate they may be used as needed in relation to reference frames171or173, as well as the various reference frames shown inFIG.5B. Additional description is included below. Persons of skill in the art will understand the various support structures may support a single object as shown, or optionally they may support two or more similar or dissimilar objects. For example, master device support structure160may support two master devices110(e.g., one master device110for each left and right hand to control corresponding individual tools114, as illustrated by user control unit112). Or, master device support structure160may support three or more master devices (e.g., two master devices110to control corresponding individual tools114, and a third master device to control a third tool114or a camera126). Combinations of one or more kinematically grounded master devices and one or more ungrounded master devices may be supported. And, if two or more master devices110are supported, display108may or may not be supported. Similarly, tool support structure166and device support structure172may support two or more tools114, either with or without supporting camera126(e.g., the manipulator assembly116). In addition, teleoperated systems may optionally include combinations of two or more master device support structures160, display device support structures162, camera support structures164, tool support structures166, control support structures170, and device support structures172. For example, a da Vinci® Xi Surgical System has one control support structure170that supports a single display108and two master devices110, and it has one device support structure that supports one endoscopic camera126and up to three tools114. The da Vinci® Xi Surgical System optionally includes a second control support structure170that supports a second single display108and a second set of two master devices110, and this second support structure may be used for example in training situations. Persons of skill in the art will understand the various reference frames illustrated may optionally be combined in various ways to be a single reference frame when kinematically possible. For example, master device support reference frame161or control support reference frame171may be used as master device reference frame156. Likewise, display reference frame154may be used as master device reference frame156. Similarly, camera body reference frame153(the imaging device body reference frame) may be used as the FOV reference frame. To avoid needless description, all the various combinations are not listed, but all such combinations are within inventive aspects. In general, a reference frame associated with any link, including the distal-most link, in one kinematic chain may be used as a reference frame associated with any link, including the distal-most link, in a second kinematic chain. The kinematic relationship between the two reference frames is established as necessary in accordance with inventive aspects. As described above, when display108and one or more master devices110are supported in a common control support structure170, and when kinematic pose information about display and the master devices is determined, well-known kinematic calculations can be used to establish the required control alignment between reference frames associated with the display and one or more masters. This is because the position and orientation relationship between display108, the one or more master devices110, and the control support structure170is known. Similarly, when camera126and one or more tools114are supported in a common device support structure172, well-known kinematic calculations can be used to establish the required control alignment between reference frames associated with the camera and its FOV, the one or more individual end effectors140corresponding to one or more individual tools114, and the device control structure because the position and orientation relationship between these objects is known. To establish the control alignment required for teleoperation (e.g. for telesurgery in surgical examples), the control support reference frame171is transformed to the device support reference frame173, and so the master/display and camera end effector/FOV reference frame alignment is established. For example, new teleoperated system architectures may lack a single mechanical base common to the tools that can be used in determining the kinematic relationships among the tools. Similarly, new teleoperated system architectures may lack a mechanical base common to the master input devices that can be used to determine the kinematic relationships among the master input devices, or between the master input device(s) and other equipment such as a display. Thus, there is a need to for improved spatial registration and control in teleoperated systems. For example, a teleoperated system may comprise two or more units that carry tools, where the units are moveable with reference to each other such that the kinematic relationship between units is not readily defined by being mounted to the same mechanical base. Further, a tool (such as a manipulation tool or a camera) may be supported by a passive support structure that is not instrumented with any sensors, or the tool may be held by a human, and so a computer control system is unable to determine the tool's kinematic information from the tool's support structure. Consequently, there is no single mechanical base common to these units that can be used to determine the kinematic relationships among the tools held by different units (e.g. among an endoscopic camera and one or more other medical tools, in a medical embodiment). In addition, one or more units may be added or removed as needed during a procedure (e.g. during a surgical procedure in surgical examples). A similar situation may exist with master control devices used to control motion of the tools in these new systems. Master control devices may not share a common mechanical base, and the kinematic relationship between a display (e.g. one showing an image of a work site captured by an imaging device) and one or more master control devices (e.g. master input devices used to control the pose of one or more tools, such as one or more manipulation or imaging tools) may not be determinable from kinematic data alone. In addition, one or more master input devices may be added or removed as needed during a procedure. Thus, in a situation in which one or more individual master device, display, imaging device, and tool support structures is used, however, the position and orientation relationship between the masters and the display, and between the imaging device and the other tools, is more difficult to establish. If position and orientation are to be used to establish the required control alignment, then both the position and the orientation of each separate support structure must be determined. And further, if the position or orientation of a separate support structure changes during use (e.g. for surgery in surgical examples), the new position and orientation of the changed support structure must be determined to again establish the required control alignment. But, it is often difficult to determine the position and orientation of the separate support structures with sufficient accuracy. FIG.5Dis a schematic plan view of a medical example, showing a patient and two patient-side units that illustrates an example situation in which separate camera and tool support structures are used during a medical procedure. A patient200is shown on an operating table202. An illustrative camera support structure204is shown as a mobile unit that can be moved across the operating room floor. As described above, camera support structure204supports endoscopic camera206, which has an FOV posed toward work site208(a medical site such as a surgical site in this example) within the patient. An illustrative tool support structure210is included, also shown as a mobile unit that can be moved across the operating room floor. Tool support structure210supports tool212, which is posed to locate its end effector214at the surgical site within the patient and the FOV. Camera support structure204represents a single camera support structure supporting a single camera, a single camera support structure supporting two or more cameras, and two or more individual camera support structures each supporting one or more cameras. Likewise, tool support structure210represents a single tool support structure supporting a single tool, a single tool support structure supporting two or more tools, and two or more individual tool support structures each supporting one or more tools. Further, camera support structure204and tool support structure210optionally represent combined device support structures as described above. Thus, to avoid a needlessly long description of all the possible variations, persons of skill in the art will understand the description that follows about camera support structure204and tool support structure210also applies to the various other support structures each may represent. As shown, camera support structure204is at a certain pose204awith reference to a mechanical ground (in this example, the floor216). Camera support structure reference frame218is associated with an individual link of the camera support structure's kinematic chain (e.g., the base link at the mechanical ground, a link of a setup structure, a link of the manipulator, a link of the camera itself; the pose of the camera's distal-most link, which may be the camera body itself, is used also define the camera FOV's reference frame). The camera support structure reference frame218orientation changes as the associated individual link orientation changes, and kinematic calculation is then used to determine the orientation of any other link in the camera support structure. This changing orientation aspect is further shown inFIG.5Dfor tool support structure210, which is shown at a first pose210awith reference to the mechanical ground (floor216). Tool support structure reference frame220is associated with an individual link of the tool support structure's kinematic chain (e.g., the base link at the mechanical ground, a link of a setup structure, a link of the manipulator, a link of the tool itself, including the end effector).FIG.5Dfurther shows tool support structure210at a second optional pose210bwith reference to the mechanical ground, which illustrates that the tool support structure may be placed at various positions and orientations for and during teleoperation (e.g. during telesurgery in surgical examples). Reference frame220changes as its associated link on the tool support structure changes, as shown by arrow222. Persons of skill in the art will understand that the various poses of tool support structure210as shown also represent various poses of one or more additional individual or combined tool structures, as well as optional poses of camera support structure204and optionally one or more additional individual or combined camera support structures, as well as one or more camera and tool support structures combined into one or more separate individual device support structures. But, for all these optional combinations, the support structure that supports the camera is separate from the support structure that holds the tool that requires registration in the camera's FOV reference frame. FIG.5Eis another schematic plan view of a patient and two patient-side units that shows a second example of changing orientation for separate camera and tool support structures. InFIG.5E, the camera and tool support structures are mounted on the table202(e.g., medical table in medical examples, such as surgical tables in surgical examples). For example, the camera and tool support structures may be mounted at various positions along the table's side rail(s)), which serves as a mechanical ground. Camera support structure224for camera206is mounted to table202at base position224a. Similarly, tool support structure226for tool114is mounted to table202at a first base position226a. Tool support structure226is optionally mounted to table202at a second base position226b, which again illustrates that the tool support structure may be placed at various positions and orientations for and during teleoperation (e.g. during telesurgery in surgical examples). InFIG.5Dboth the position and orientation of the tool support structure's base was shown changed, and inFIG.5Eonly the position of the tool support structure's base is shown changed, since the base orientation does not change as it is at various positions along the table rail. But, the tool support structure base position and orientation may change in other configurations, such as when the tool support structure is moved from one side of the table to the opposite side of the table. In addition, the table pose may change, which correspondingly changes the base orientation and position. Again, as discussed above, various combinations of camera and tool support structures are possible. And again, for all these optional combinations, the support structure that supports the camera is either completely physically separate from the support structure that holds the tool that requires registration in the camera's FOV reference frame, or is mechanically coupled via a shared support structure that also holds the tool but without shared kinematic information and is therefore effectively kinematically separate. 2. Alignment for Control In order to effectively move the distal end of the tool in relation to the camera FOV reference frame, an alignment relationship is determined between the camera FOV and the end effector of the tool—that is, between the reference frame associated with the camera FOV and the reference frame associated with the end effector. In addition, an alignment relationship is determined between the master device and the display that outputs an image from the camera that shows the end effector—between the frame associated with the master control and the frame associated with the display. An example of establishing such an alignment relationship and forcing a master device to a pose that corresponds to a displayed end effector pose is found U.S. Pat. No. 6,424,885 B1 and in U.S. Pat. No. 6,459,926 (filed Sep. 17, 1999), the disclosure of which is incorporated by reference in its entirety. In these examples, a master device is mounted at the end of a robotic master manipulator arm. To establish the necessary master/slave control relationship, the master manipulator arm moves the master device to a pose in the display reference frame that corresponds to the pose of the slave end effector in the camera FOV reference frame. This movement aligns the master device pose with the displayed end effector pose, and so a visually and proprioceptively intuitive control relationship between the master device and the end effector is established. Thus, in various embodiments, the relationships between the end effector reference frame and the FOV reference frame, and between the display reference frame and the master device reference frame, are determined. In implementations, a user's perception of intuitive master/slave control depends on at least two major perceived correlations between master and slave. First, it depends on the user's perception of the correlation between the master's (the master device) orientation in space and the slave's (end effector) orientation in space—perceived orientation correlation. Second, it depends on the user's perception of the correlation of the master's (master device) direction of movement with the slave's (end effector) direction of movement—perceived direction of movement correlation. Therefore, the user's proprioceptive sense of the master device's orientation should be within an acceptable tolerance of the user's visual sense of the corresponding end effector image's orientation in the display. For many tools and/or master devices, the long axis of the master device should be perceived as oriented in the direction of the long axis of the end effector in the display. For other tools and/or master devices, however, the master device and/or end effector orientation axes used for control may be other than the long axis. As an example, a pistol grip style master device may not have a long axis perceived as aligned with an end effector's long axis, but the user still perceives an orientation correlation between the pistol grip master and the end effector. Further, if the end effector has a grip function that intuitively corresponds to a master device's grip motion, the orientation of the plane of the master device's grip motion should be perceived as corresponding to the orientation of the plane of the end effector's grip motion in the display. (This is a match between the master device's roll angle around its actual or perceived long axis and the end effector's roll angle around the end effector's long axis.) Likewise, the user's proprioceptive sense of the master device's direction of movement should be within an acceptable tolerance of the user's visual sense of the corresponding end effector image's direction of movement. Individual users will have different personal tolerances for perceived orientation and direction of movement correlations. For example, some users may tolerate a perceived orientation correlation mismatch of 20-40 degrees. And, some users are affected by a perceived direction of motion correlation mismatch as low as 5 degrees. We have found that when a telesurgical system first establishes a control relationship between master device and end effector to begin master/slave operation, and as the system continues to update and maintain the control relationship between master device and end effector during master/slave operation, the perceived master/slave orientation and direction of movement correlations are more important than the perceived position correlation for adequate performance. Referring toFIG.5F, an orientation alignment axis ZELis associated with the displayed image of the left end effector, and an orientation alignment axis ZERis associated with the displayed image of the right end effector. Likewise, an orientation alignment axis ZMLis associated with the left master device, and an orientation alignment axis ZMRis associated with the right master device. The master devices with their orientation axes at ZML1and ZMR1are at positions spaced apart in a way generally corresponding to the way the end effector orientation axes ZELand ZERare spaced apart. The master device orientation axes ZML2and ZMR2, however, are spaced apart farther than the way the end effector orientation axes ZELand ZERare spaced apart. Nevertheless, the positions of master device orientation axes ZML2and ZMR2provide effective intuitive control. In a similar way, differences in vertical (e.g., left higher than right) or depth (e.g., left farther away than right) positions of master device orientation axes ZML2and ZMR2also provide effective intuitive control. For example, effective control can be established and maintained with the position of the right master device orientation axes at ZML1and the left master device orientation axis at ZMR2. Still referring toFIG.5F, a 3D spatial movement VMR1is associated with the right master device at the first master device position, and a parallel 3D spatial movement VMR2is associated with the right master device at the second master device position. Both of these movements VMR1and VMR2are perceived as correlated to the right end effector's 3D spatial movement VERfor effective intuitive control, despite the right master device being at positions spaced apart in 3D space. 3. Orientation Alignment and Orientation-Only Alignment In order to provide the required perceived correlation in orientation and direction of movement between master device and end effector for the user's effective intuitive control, the control system determines and aligns the relationships between associated frames, both to begin master/slave control for teleoperation (e.g. for telesurgery in surgical examples) and to maintain and update master/slave control during teleoperation (e.g. for telesurgery in surgical examples). In accordance with an inventive aspect, the required alignment relationships between the camera FOV and the end effector, and between the master device and the display are established with reference to only the orientations of these objects and not with reference to their positions—that is, with reference to the orientations of the reference frames associated with these objects and not with reference to the positions of the reference frames associated with these objects. For control, absolute orientation is determined between an end effector alignment orientation axis and a camera FOV alignment orientation axis, and absolute orientation is established between a master device alignment orientation axis and a display alignment orientation axis. When the orientation relationships are determined for control, the end effector may be located within or outside the camera FOV. In accordance with an inventive aspect, the required alignment relationships between the camera FOV and the end effector, and between the master device and the display, are established with reference to the full orientations of these objects but with reference to less than their full positions. The full orientation is also called “complete orientation”, and the full position is also called “complete position”. Examples of less than full position information include no position information, and partial position information such as position information along only one or two axes. Thus, in an example utilizing Cartesian coordinates, the required alignment are established with reference to the orientations of the reference frames associated with these objects around all three Cartesian axes (e.g. rotation around the X, Y, and Z axes), and with reference to the positions of the reference frames associated with these objects along zero, one, or two Cartesian axes (e.g. along none of the X, Y, or Z axes, or along only one or two of the X, Y, and Z axes). Control is then established by using the full orientation information and less than the full position information. The following description concentrates on using orientation information, and it should be understood that in addition, less than full position information (i.e., along zero, one, or two Cartesian axes) may be optionally combined with full orientation information to establish and maintain control as described. A full homogeneous transformation may be used but is not necessary to establish and maintain effective alignment between reference frames for intuitive control. Once the orientation of any individual link in the kinematic chain for these objects (which may be the object itself) is known, an effective control relationship can be established with less than full position information for that individual link. Less than full position information for a link may mean no position information for that link, and some embodiments use only orientation information for establishing the control relationship. Using only orientation for alignment simplifies the alignment task because it eliminates the need either to determine the absolute or relative position of these objects or of their support structures, or to construct combined support structures that establish a common reference frame for these objects or support structures. Less than full position information may also mean partial position information, and some embodiments use orientation information and partial position information in establishing the control relationship. Using partial but not full position information also simplifies the alignment task by reducing the amount of position information that is determined. Thus, various separate individual objects and their support structures, as illustrated inFIGS.5B-5E, may be properly aligned for control. The required alignment relationships to establish effective control are carried out by well-known kinematic transforms from one reference frame to another reference frame. Once the initial orientation alignment relationships (e.g. orientation-only alignment relationships, or complete-orientation-with-partial-position alignment relationships) required for effective teleoperation control are established among the various reference frames, then changes in both position and orientation with respect to these reference frames are used to carry out teleoperation (e.g. telesurgery in surgical examples). For example, a change in position of a master device is carried out as a corresponding 1:1 or scaled change in position of a tool's end effector, a change in orientation of a master device is carried out as a corresponding change in and orientation of a tool's end effector, and a change in pose of a master device is carried out as a corresponding change in pose of a tool's end effector. But while these control relationships function during teleoperation, the alignments between the frames may be maintained by using only the orientations of the frames and not with reference to their positions, or by using the orientations with reference to less than their full position information. In one aspect, the end effector orientation is determined in relation to the tool's shaft orientation in accordance with the wrist function. In some instances, all three end effector orientation DOFs with respect to the shaft are independent of the shaft to which the end effector is coupled. In other instances, fewer than the three end effector orientation DOFs with respect to the shaft are independent of the shaft. For example, the end effector pitch and yaw DOFs may be independent of the shaft, and end effector roll orientation around the z-axis is determined by a shaft roll DOF. As another example, the end effector yaw DOF may be independent of the shaft, but end effector pitch and roll is determined by corresponding shaft pitch and roll DOFs. Thus in some instances in which a transform from a tool reference frame to an end effector reference frame occurs to establish the alignment required for control, three, two, or one rotation may be required, depending on the tool's distal end configuration. In one aspect, the orientation of the end effector reference frame is determined in relation to a reference frame other than the tool's reference frame. For example, as described in more detail below, the orientation of the end effector reference frame is determined with reference to the orientation of a reference frame of a field of view (FOV). For example, in an endoscopic surgery example, the orientation of the end effector reference frame (for a tool in the surgical site) is determined relative to the orientation of a field of view reference frame (for an endoscopic camera having a FOV covering the surgical site in part or whole, also called a camera FOV). In this example, the end effector may be located inside or outside of the field of view associated with the field-of-view reference frame. In one aspect, the orientation of the input device frame is determined in relation to a reference frame of an image displayed by a display, and viewable by a user interacting with the input device. In accordance with another inventive aspect, the initial orientation alignment relationship (e.g. orientation-only alignment relationship, or complete-orientation-with-partial-position alignment relationships) required for control is established when an event in the teleoperated system occurs, such as the teleoperated system's computer receiving a signal that indicates the user wishes to begin teleoperation control. Such an event may be a button press or other actively controlled event so that teleoperation is not begun by mistake. Examples of such system events may be at a transition between teleoperation of one or more tools and teleoperation of one or more endoscopic cameras, exchanging a first tool for a second tool on a teleoperated manipulator, and other actions that are expected to occur throughout a procedure (e.g. through a surgical procedure in surgical examples). As a specific example, one event that optionally may be used to trigger the request to establish the control relationship is an exit from a “clutch” mode in which the master/slave relation between the master control device and the end effector is temporarily suspended. The clutch mode is analogous to the use of a mechanical clutch that engages and disengages a coupling between objects. As shown inFIG.5G, at a first time t1 a master device orientation axis ZM is at a first position as shown and is perceived as correlated in orientation and direction of movement with the orientation axis ZE of the image of the corresponding slave end effector. That is, the user teleoperates the end effector and senses that the z-axis ZM of master device at time t1 is aligned with the z-axis ZE of the image of the end effector as shown. The user then enters the clutch mode, moves master device to a second position as shown by the arrow, and exits the clutch mode at time t2. At t2 the user again perceives that the orientation axis ZM of master device correlated in orientation and direction of movement with the orientation axis ZE of the image of the end effector as shown, although at t2 the orientation axis ZM is at a different position that at t1. In accordance with another inventive aspect, the initial orientation alignment relationship (e.g. orientation-only alignment relationship, or complete-orientation-with-partial-position alignment relationships) required to establish control is updated during teleoperation to further refine the relationship, to correct for possible drift in various sensors and other system components, etc. These updates are optionally carried out using only orientation information and not position information. Updates may optionally occur at various times, such as at a predetermined time interval or at one or more system events. As an example of an update at a predetermined time interval, end effector pose is updated approximately every 1 ms (millisecond) to correspond to the master pose, and so the alignment relationship is updated each 100 cycles (approximately every 100 ms). Further, updates may be made at a combination of system events and predetermined time intervals, such when teleoperation is reestablished after a master device clutch movement, and then at a predetermined number of clock cycles after that. As an alternative, the alignment relationship between frames may be refined by a ratcheting procedure, for example as described in U.S. Pat. No. 8,423,186 B2 (filed Jun. 30, 2009), which is incorporated herein by reference, to converge on master device and end effector perceived alignment in orientation after an event such as clutching. For example, where the orientation of the input-device reference frame relative to the display frame is a first relative orientation and the orientation of the end-effector reference frame relative to the field-of-view reference frame is a second relative orientation, and the first relative orientation differs from the second relative orientation by a difference, the system can update the second alignment relationship multiple times to gradually reduce the difference. As another example, the system can integrate the orientation difference, and apply a portion of the integrated difference to commanded motion. In this alternative, the end-effector reference frame changes with commanded motion, and the commanded motion dynamically reduces the orientation difference. In an implementation, the system determines: a commanded change in orientation of the end effector, a residual orientation difference, a maximum reduction of the difference (such as a percentage of commanded change in orientation that still maintains orientation intuitiveness, in some cases being limited to a maximum of +/−20% of commanded motion). Then, the system modifies the commanded motion by adding an amount based on the residual orientation difference (such as the residual orientation difference scaled by a scale factor). Such a scale factor can be limited by a maximum scale factor. In accordance with another inventive aspect where only orientation is used in the alignment relationship, the orientations of various objects and links in kinematic chains may be determined in various ways, as illustrated below. And, even though position information for these objects and links may also be determined, in these aspects it is the orientation information alone that is used to initially establish the alignment relationship required for control, and then to maintain and update the alignment relationship. FIG.5His a schematic view of teleoperated (e.g. telesurgical in surgical examples) system components and reference frames associated with these components. Where applicable, components are analogous to components illustrated inFIGS.5A-5F. As shown, camera tool502(also “camera502”) has an associated camera tool reference frame503. Camera tool502has an FOV504(2D or 3D), which has an associated FOV reference frame505. If the distal objective end506of camera tool502is not steerable with reference to the body of the camera tool, then camera tool reference frame503and FOV reference frame505may be combined. Camera support structure508supports camera tool502at a distal end. In some implementations camera support structure has a single link, and in other implementations it has two or more links with each pair of links coupled by a joint. As shown, one link of camera support structure508is identified as a camera support target link510, and a dedicated spatial indicator target512is optionally fixed to target link510. Camera tool support structure reference frame513is associated with target link510or target512as appropriate. Camera support structure508further includes a proximal base link514at a mechanical ground516(e.g., coupled to floor516a, to wall516b, to ceiling516c, or to a structure itself at a mechanical ground, such as a table (fixed or movable) or movable cart). Base link514is optionally movable with reference to ground, as indicated by the directional arrows, but is otherwise in a fixed relationship to ground during initial alignment and operation. In some optional implementations, camera support structure508is omitted and camera502is supported by a person during a procedure. In such an optional implementation, target512is optionally fixed to camera tool502, and camera tool reference frame503and camera tool support structure reference frame513are combined. Tool520has an associated tool reference frame521. Tool520has a distal end effector522, which if applicable has an associated end effector reference frame523because it is movable with respect to the body of tool520. Tool support structure524supports tool520at a distal end. In some implementations tool support structure has a single link, and in other implementations it has two or more links with each pair of links coupled by a movable joint. As shown, one link of tool support structure524is identified as a tool support target link526, and a dedicated target528is optionally fixed to target link526. Tool support structure reference frame529is associated with target link526or target528as appropriate. Tool support structure524further includes a proximal base link530at mechanical ground516(e.g., coupled to floor516a, to wall516b, to ceiling516c, or to a structure itself at a mechanical ground, such as a table (fixed or movable) or cart). Base link530is optionally movable with reference to ground, but it is otherwise in a fixed relationship to ground during alignment and operation. Spatial orientation determining unit531determines the orientations of camera support target link510, camera support spatial indicator target512, tool support spatial indicator target link526, camera support spatial indicator target528, and camera502, or a subset of these depending on how the orientations are determined, as required for the system configuration. Orientation determining unit531optionally uses any of various known ways to determine the orientation, such as kinematics, electromagnetic localization and other RF-based methods, ultrasonic or acoustic localization, optical tracking based on dedicated targets or natural features, and optical fiber shape sensors. Details are described below. Orientation determining unit531is optionally centralized at a single location or distributed at two or more locations, may be optionally integrated into one or more teleoperated system units and support structures, and may be optionally worn by the user. In some implementations where only orientation information is used for an alignment relationship, the system is configured to sense only orientation information for such alignment relationship. For example, a kinematic support structure is instrumented to only sense joint orientation. Omitting sensors simplifies the design and saves cost. Therefore, in some optional implementations two mechanically-connected support structures are instrumented to sense only orientation and not position. For example, in a kinematic chain support structure for a tool manipulator or a master device, rotational sensors are used to sense rotational joint angles, but position sensors to sense prismatic joint positions are omitted. Likewise, for ungrounded devices, optionally only orientation and not position is sensed, since only orientation may be used to establish and maintain the intuitive control relationship between master and slave devices. In some other implementations that use only orientation information for an alignment relationship, position information is partially or fully sensed. Also shown is an optional world reference frame532and gravity vector (g), which may be used to define or determine one or more of the reference frames or to sense a change in orientations of one or more of the reference frames. World reference frame532is optionally used for the kinematic transformations between the various system component reference frames. FIG.5Hfurther shows a display534on which images from camera tool502are displayed. Display reference frame535is associated with display534. Display534is supported with reference to ground516. When the distal end of tool520is in FOV504, a corresponding image is displayed on display534and is viewed by the user540(e.g. a surgeon or skilled clinician or other personnel in medical examples). The user540holds master device536, which has an associated master device reference frame537. Master device536is optionally mechanically grounded or ungrounded, as symbolized by the dashed line to ground516. Whether grounded or ungrounded, the orientation of master device536—the orientation of master device reference frame537—is sensed and determined by master orientation determining unit538, which optionally uses any of various known ways to determine the orientation, such as kinematics, optical tracking, or other wireless tracking (e.g., technology supplied by Leap Motion, Inc., San Francisco, California, U.S.A.). For control purposes, an orientation of master device reference frame537may be determined with reference to a reference frame on a kinematic support structure (if applicable) or with reference a fixed reference frame, such as master orientation unit reference frame539or world reference frame532. FIG.5Halso shows the user540oriented (standing, seated) to ground516. An optional user reference frame542is associated with user540. User reference frame542is a body-centric reference frame defined with reference to a point on the user's body (e.g., the eye, another position on the body, clothes or equipment the user is wearing, etc.). A centralized or distributed computer control system550receives information about the orientations of the various teleoperated system components and performs the rotational transforms necessary to establish the initial alignment relationships required for effective teleoperation control and maintain the alignment relationships as required. When the alignment relationships are established and any other conditions necessary for entering a master/slave control mode are met, computer control system550outputs a command to operate in the teleoperated system in the master/slave control mode. Examples of optional required conditions to enter the master/slave control mode are a determination that the end effector is in the camera FOV, a determination that the user is looking at the display (see e.g., U.S. Provisional Patent Application No. 62/467,506 (filed Mar. 6, 2017), which is incorporated herein by reference), and other safety-related conditions. In general, computer control system550establishes the required initial orientation alignment relationships to enter the master/slave following mode between master device536and surgical tool520. Relative orientation transform relationships are established between the end effector frame and the FOV frame and between the master device frame and the display frame. A direct transform relationship between master device frame and end effector frame is not required. As described above, the transform relationships for the initial alignment do not account for position information of the end effector or master device. The chain of transforms varies depending on the system architecture and the various reference frames that may apply to the components in the system architecture. In some embodiments, the required initial orientation alignment relationship is an orientation-only alignment relationship, and the associated transform relationship is an orientation-only transform relationship that transforms only the orientation. In some embodiments, the required initial orientation alignment relationship is a complete-orientation-with-partial-position alignment relationship, and the associated transform relationship is a complete-orientation-with-partial-position transform relationship that transforms position only partially, such as only along one or two axes in a three-dimensional space. For example, with reference toFIG.5H, a transform relationship from master device reference frame537to end effector reference frame523may include a transform from master device reference frame537, to master orientation unit reference frame539, to tool support structure reference frame529, to tool reference frame521, to end effector reference frame523. Optionally a transform to and from world reference frame532is included, generally between reference frames associated with a control unit and a patient-side unit. In addition, computer control system550establishes an initial orientation transform relationship between master device reference frame537and display reference frame535. In some embodiments, the initial orientation transform relationship is an orientation-only transform relationship. In some embodiments, the initial orientation transform relationship is a complete-orientation-with-partial-position transform relationship. When establishing the initial master/slave relationship between master device and end effector, the reference frame transform chain between master device and end effector is established for the master device for any master device position and orientation in space at which the user is holding the master device. The user may choose to visually align the positions and orientations of the master device and the displayed end effector images, but the user is not required to do so in order to establish the control alignment. That is, the user may choose to hold the master device without visually aligning the positions and orientations of the master device and the displayed end effector image. For example, the user may hold the master device at the chest or abdominal level, out of the user's field of view, optionally placing the forearm on an armrest for stability and fatigue reduction. As another example, the user may be oriented at an oblique angle away from the display while holding the master device when initial control alignment is established. For example, a user's shoulders may be turned 45 degrees from the display so that the user can operate a master device in one hand and a manual tool (e.g. a laparoscopic tool in surgical examples) in the other hand. In an aspect of establishing the master/slave relationship between master device and end effector, master/slave teleoperation is optionally allowed on the condition that the master device is within a certain orientation tolerance. The tolerance may be based on the master device's orientation within the master orientation unit reference frame (FIG.5H, element539). Or, the tolerance may be based on the master device's orientation within the display reference frame (FIG.5H, element535), which in effect bases the tolerance on based on the orientation of the displayed image of the end effector. Or, the tolerance may be based on the master device's orientation within some other reference frame. The orientation tolerance may apply to one (e.g., roll), two (e.g., pitch and yaw), or all three rotations in Cartesian space. And, orientation tolerances for each of these rotations may be different. For example, if the master device includes a grip DOF within a plane, then the roll tolerance with reference to the end effector's corresponding grip DOF plane may be smaller (e.g., ±10°) or larger (e.g., ±20°) than the pitch or yaw tolerances (e.g., ±15°) with reference to the end effector's pitch and yaw. FIG.5Iis a diagrammatic view that illustrates the requirement for the master device orientation to be within a certain tolerance of the displayed end effector orientation in order to establish alignment for control. As depicted, an image522aof end effector522is shown on display534. From the established kinematic relationship between FOV reference frame505and end effector reference frame523, an orientation560of the end effector image522ain display reference frame535is determined. (For clarity, reference number560is shown twice in the figure—once in relation to the display, and once in relation to the display reference frame.) Then, an alignment tolerance562is determined with reference to the orientation560. InFIG.5Ithis tolerance is illustrated by a circular cone having orientation560as its central axis. Other alignment tolerance shapes may optionally be used, such as elliptical cones, pyramids, and similar shapes that can be defined with reference to the orientation axis. The kinematic relationship between the display reference frame and the master device reference frame is determined. Then as a first example, as shown inFIG.5Imaster device536ais determined to have an orientation564a. Orientation564ais determined to be within alignment tolerance562, and so master/slave control between master device536aand end effector522is permitted. As a second example, master device536bis determined to have an orientation564b. Orientation564bis not within alignment tolerance562, and so master/slave control between master device536band end effector522is not permitted until orientation564bis determined to be within alignment tolerance562. In some instances the control alignment is automatically established as soon as the master device orientation is within the alignment tolerance, and optionally a visual, audio, haptic, or similar indication is output to the user as a signal that the master/slave control relationship is in effect. A ratcheting function as described above may be used. For the required control relationship to be established in other instances, in addition to the master orientation being within the alignment tolerance, the system must receive another event, such as a button press, verbal command, or similar input that requests the control relationship be established. This approach to establish a master device orientation tolerance in order to begin master/slave control applies to situations in which the tolerance is based on other reference frames. In some instances in which a master control is at the distal end of a robotic arm, the control system550optionally commands the robotic arm to orient the master device's orientation alignment axis with reference to the master orientation unit reference frame (FIG.5H, element539), or the display reference frame (FIG.5H, element535), or some other reference frame. For example, control system550may command the arm to place the master device at an aligned orientation with reference to the displayed end effector image, and it commands the arm to place the master device at a defined default position with reference to the display, or at the current position with reference to the display, instead of at a position corresponding to the displayed image of the end effector. If two master devices are used to control a single object, the perceived orientation and direction of movement correlations between the master devices and the object may be perceived orientation and direction of movement correlations between the master devices acting together and the object. An example might be the two master devices acting as a handle bar with a straight connecting axis between them. As the master devices are moved together to change the position of the connecting axis, the position of the object correspondingly moves (e.g., a camera FOV moves up-down, left-right, in-out). As the master devices are moved together to change the orientation of the connecting axis, the orientation of the object correspondingly changes (e.g., a camera FOV tilts up-down, pans left-right, rolls clockwise-counterclockwise). Here again only orientation information need be used, and position information is not required. For example, the masters may be spaced close together or far apart on the connecting axis, and the spacing on the connecting axis may change as the object is controlled (e.g., farther apart provides finer orientation control; closer together provides increase range of motion). As shown inFIG.5J, for example, a connecting axis XML-MRis defined between left and right master devices. A normal axis ZML-MRmay also be defined for control. As axis XML-MRis moved to the left, a camera is either translated or rotated to move correspondingly, optionally either giving the user the sensation of moving the scene to the right (FOV moves right as shown) or the camera to the left (FOV moves left). The camera may translate or rotate as shown. Insertion and withdrawal is controlled by movements along axis ZML-MR. Changes in elevation along another mutually orthogonal axis YML-MRmay also be done. Similarly, the FOV position or orientation may be controlled by rolling around the connecting axis and its Cartesian orthogonals (e.g., FOV tilt by roll around XML-MR, FOV pan by roll around YML-MR, and FOV roll by roll around ZML-MR). Approaches similar to ones used to establish initial alignment relationships may be used to maintain alignment relationships during teleoperation as described herein. 4. Determining Spatial Relationships As discussed above, the operational environment of a teleoperated system may include two or more manipulators for various tool and camera combinations. For example, the patient-side environment of a telesurgical system may include two or more manipulators for various surgical tool and endoscopic camera combinations. And, one or more of these manipulators may not have a predetermined fixed spatial relationship with respect to the other manipulators. Similarly, there may not be a predetermined fixed spatial relationship among the one or more master devices and the display screen. In this situation, it is not possible to establish and maintain the control relationship necessary for teleoperation based only on sensing the angular relation between the various kinematic pairs (e.g., by using joint angle or similar sensors) and kinematic transformations for each individual unit. The spatial relationships between units are determined in order to establish and maintain effective intuitive control. FIG.6Ais a schematic view of a teleoperated system (specifically a telesurgical system is shown) that incorporates inventive aspects of determining spatial relationships. For simplicity, several aspects are illustrated as incorporated intoFIG.6A, and various optional telesurgical system configurations are described further below. Not all depicted and described aspects are required in a single embodiment. Objects depicted inFIG.6Aare analogous to objects depicted inFIGS.5A-5J, as applicable (e.g., tools, endoscopic camera, support structures, control system, spatial sensors, movable units, etc.). As shown, there are two teleoperated surgical tools602a,602b, each with a corresponding end effector603a,603b. Each tool602a,602bis actuated by a corresponding manipulator604a,604b, each mounted on a corresponding base606a,606bto make up a corresponding patient-side unit608a,608b. Likewise, an endoscopic camera610is shown, and it has a FOV612. Endoscopic camera610is actuated by a corresponding manipulator614, which is mounted on a base616, and together they make up a patient-side unit618. As shown, the patient-side units608a,608b, and618are movable with respect to one another—there is no mechanical support structure common to any of them that fully constrains their relative spatial relationships. Hence, the patient-side units608a,608b, and618are generally as described above. Each surgical tool602a,602benters the body via a corresponding optional cannula620a,620b. Likewise, endoscopic camera610enters the body via optional cannula622. The tool end effectors603a,603bare positioned within FOV612. Three optional vibration sensing/injecting units624a,624b, and624care shown, each attached to a corresponding one of the cannulas620a,620b, and622. Alternatively, vibration sensing/injecting units624a,624b, and624cmay be coupled to any position on a patient-side unit or other telesurgical system unit. Captured image data625travels from endoscopic camera610to optional machine vision processor626. Image data625also travels to display image processing unit628, which in turn processes the captured image data and outputs display image data630for display. Machine vision processor626outputs machine vision spatial data632for use as described below. FIG.6Aalso shows master devices634a,634bto be operated by a user. Each master device634a,634bis supported by a corresponding mechanical support structure636a,636b. As shown, support structures636a,636bare mechanically coupled in a fixed spatial relationship and are each mounted to a movable common base638. Optionally, each support structure636a,636bis mounted to a separate movable base. Also shown is an optional grounded or ungrounded master control device configuration640, in which the master device641poses are sensed by master device spatial sensing unit642(see alsoFIG.5H, orientation determining unit538;FIGS.5B and5C, control input receiver160c). Spatial sensing unit642may be fixed in space, or it may optionally be mounted to a movable base644. Display646is optionally mounted at a fixed position, mounted on movable support structure648, or worn by the user. Support structure648may have a base that is fixed in space, or the base may be mounted to a corresponding movable mechanical base650, or the base may be mounted on a base common to the base corresponding to the master control devices, such as base638or base644. Hence, the components associated with master control devices634a,634band display646are generally as described above. FIG.6Afurther shows a control system652for the telesurgical system (see alsoFIG.5H, control system550;FIG.4, computer113). Control system652executes programmed instructions to carry out the alignment and other system control functions as described herein. Control system652is in signal communication with patient-side units608a,608b, and618. It is also in signal communication with master devices634a,634b. By this signal communication, control system652receives spatial information654a,654bassociated with end effectors603a,603b, spatial information654cassociated with FOV612, and spatial information654d,654eassociated with master devices634a,634b. Optionally, control system652receives spatial information654fassociated with display646if it is not mechanically coupled to a master device. Optional spatial indicators656a-656fare mounted to bases606a,606b,616,638,644, and650. As shown, spatial detecting unit658(centralized or distributed sensing) is associated with spatial indicators656a-656c, and spatial detecting unit660(centralized or distributed sensing) is associated with spatial indicators656d-656f. Optionally, however, a single spatial detector unit may be associated with all spatial indicators in a telesurgical system. Referring toFIG.5H, targets512,528and orientation determining unit531are examples of spatial indicators and detectors. Therefore, inventive aspects determine the spatial relationships between telesurgical system units that are not in permanent, fixed mechanical relationships. The relationships are determined in order to establish, achieve, and maintain intuitive motion based on inputs from the user's master control devices, but with acceptable interference, or without interfering, with the operating room environment. For example, the spatial relationship between manipulators for the end effectors and the endoscopic camera, or directly between the end effectors and endoscopic camera themselves, is determined when there is no fixed mechanical relationship between them. The determined relationships are then used to establish the transformations necessary for the teleoperated control relationship. At a minimum, only the orientations are determined. In some implementations, however, some position information may be determined for one or two axes, or full pose information may be determined. In some aspects the spatial determination methods use external hardware, such as spatial indicators656a-656fand spatial detecting units658,660. But, this external hardware is sized and positioned so that it does not interfere with the operating room environment. In other aspects, the spatial determination methods do not require additional hardware and are contained within a telesurgical system's existing hardware. For example, an additional data processing unit such as a video data processor or machine vision processor may be added inside an existing unit. Various ways may be used to determine the spatial relationship between telesurgical system units that are movable with reference to one another by localizing the units to a common single reference frame as necessary. The single reference frame may be a world reference frame that is defined apart from the telesurgical system (see e.g.,FIG.5H, frame532). Or, the single reference frame may be associated with a device in the telesurgical system, such as the base of a teleoperated manipulator unit. In the disclosure that follows, reference is made to a “reference base” of a unit, which in some implementations is the actual physical base of a unit that rests on the floor or on another supporting structure that is fixed in the world reference frame. But, persons of skill in the art will understand that the “reference base” may be arbitrarily defined at any point on a patient-side unit that remains stationary in a world reference frame during telesurgery. Since each “reference base” is movable, the relationship of the reference base or bases is determined once the reference base is at a pose that will be stationary during telesurgery. Referring toFIG.6A, bases606a,606b,616,638,644, and650are examples of such movable reference bases and will be used as illustrations of reference bases. Operating principles are illustrated in terms of the patient-side units608a,608b, and618, and these principles apply to user control units as well as applicable for a particular system configuration. Features and functions associated with spatial indicators656d-656fand spatial detecting unit660are analogous to features and functions for spatial indicators656a-656cand spatial detecting unit658. One spatial relationship determining method is to establish a temporary, localized, mechanical relationship between a pair of units (e.g., two patient-side manipulator units) by affixing a temporary, kinematically instrumented, direct mechanical coupling (e.g., a jointed linkage with joint angle sensors) between units to determine the spatial relationship. The instrumented coupling allows the kinematic relationship to be determined once the units are posed for telesurgery and reposed during telesurgery. But in some situations such mechanical localization methods are not practical for the operating room. For example, the equipment used for these methods may interfere with sterile drapes and other operating room equipment. Or, sterile drapes and other operating room equipment may interfere with the equipment used for these methods. Further, the equipment used for these methods may consume excessive space in the patient-side environment, may be expensive, and may be difficult to operate because it requires frequent calibration and other maintenance. Another spatial relationship determining method is to adapt an indoor locator system approach for use with a telesurgical system in the operating room environment. (In this context, the term “locator system” may be configured to provide some or all of the parameters orientation, some or all of the parameters for position, or some or all of the parameters for both orientation and position.) These locating system approaches may find and track actively transmitting objects, or they may find and track an object's ambient presence. One aspect of a locator system approach is to position one or more sensors on each unit to detect one or more synthetic or natural features on one or more other units. Synthetic features may actively transmit energy (a “beacon”; e.g., infrared or visible light, RFID, ultrasound) or may be passive (e.g., dedicated spatial indicator targets). The one or more sensors are used to determine a spatial relationship between one or more pairs of units, which is then used for teleoperated control as described. In some situations, however, a line-of-sight method is not practical for the operating room because the line-of-sight may be blocked by operating room equipment, sterile drapes, etc. And, if three or more units are involved, multiple lines of sight must be clear between multiple pairs of units. But, in some situations a line of sight will be nearly always be clear, such as between a unit and the operating table (see e.g., U.S. patent application Ser. No. 15/522,180 (filed Apr. 26, 2017; U.S. national stage of International Application No. PCT/US2015/057664) (disclosing “System and Method for Registering to a Surgical Table”, which is incorporated herein by reference). Another aspect of a locator system approach is to place one or more sensors at corresponding fixed positions in the operating room environment at locations which allow lines-of-sight to units (e.g., high on a wall, or on the ceiling) and to track synthetic or natural features on the various movable units. Synthetic features may be beacons or passive as described above. Spatial indicators656a-656calso illustrate natural physical features that can be sensed. An advantage of using two or more sensors is that multiple possible lines-of-sight ensure that a unit will always be detected, and multiple lines-of-sight between two or more sensors and a single unit provides redundancy and possible refinement of the determination of the unit's pose. As an example implementation of this fixed-sensor approach, a single optical sensor is placed at a fixed pose in the operating room environment, and the single optical sensor detects passive dedicated synthetic optical targets or natural features on one or more patient-side units. Spatial indicators656a-656cinFIG.6Aillustrate such targets or natural features (see alsoFIG.5H, targets512and528). A calibration establishes the spatial relationship between the coordinate frame of each target and its corresponding unit base frame. For example, spatial detecting unit658acts as an optical tracker, and the spatial relationship between spatial indicators656aand656bis determined. Then, forward kinematic transformations are used to determine the pose of each end effector603a,603bwith respect to its corresponding target. Since all target frames can be expressed in a single optical tracker frame as a common base frame, or other designated common frame, the relative transformations between end effector frames can be calculated by using a combination of measured optical tracker data and forward kinematics of the patient-side units608a,608b. As another example implementation of the fixed-sensor approach, two or more optical sensors are placed at fixed poses in the operating room environment, and the optical sensors detect passive dedicated synthetic optical targets or natural features on one or more patient-side units. Control is then established as described above. As another example implementation of the fixed-sensor approach, one or more RFID or ultrasound beacons are placed on each unit, and one or more sensors are fixed in the operating room environment to detect the beacons. The pose or poses of the one or more units are determined from the sensed beacons, and control is then established as described above. As another example implementation of the fixed sensor approach, a combination of synthetic and/or natural features is sensed. Such a combined sensor type approach offers robustness and reliability over a single sensor type approach. For example, an explicit target pattern on one patient-side unit and natural features of a second patient-side unit are sensed, or a combination of explicit target patterns and natural features of each patient-side unit are sensed. A second aspect of a locator system approach is to place one or more sensors on each movable unit and track one or more synthetic or natural features fixed in the operating room environment at locations that are easily sensed by the units (e.g., high on a wall, or on the ceiling). As with the fixed-sensor aspect, in this fixed-feature aspect synthetic features may actively transmit energy (a “beacon”; e.g., light, RF, ultrasound) or may be passive (e.g., dedicated spatial indicator targets). In this fixed feature aspect, spatial indicators656a-656cinFIG.6Aillustrate such sensors (see alsoFIG.5H, elements512and528), and spatial detecting unit658illustrates the one or more fixed features in the operating room environment. The control system receives spatial information from the one or more units, and then control is established as described above. In a manner similar to the fixed-sensor and fixed-feature locator system approaches, another alternative is the use of simultaneous localization and mapping (SLAM) technology tailored for use with a telesurgical system in an operating room environment. Various SLAM methods exist. See e.g., U.S. Pat. No. 9,329,598 B2 (filed Apr. 13, 2015) (disclosing “Simultaneous Localization and Mapping for a Mobile Robot”) and U.S. Pat. No. 7,689,321 B2 (filed Feb. 10, 2010) (disclosing “Robust Sensor Fusion for Mapping and Localization in a Simultaneous Localization and Mapping (SLAM) system”), which are incorporated herein by reference. Detection and tracking of moving objects (DATMO) technology may be combined with SLAM. See e.g., U.S. Pat. No. 9,727,786 B2 (filed Nov. 14, 2014) (disclosing “Visual Object Tracking System with Model Validation and Management”), which is incorporated herein by reference. Multiple sensors ensure sufficient coverage and overlapping operating room reconstructions in consideration of other operating room equipment (surgical table, anesthesia station, etc.) and the need to move the patient-side units in relation to such equipment. SLAM and/or DATMO sensors may be fixed in the operating room environment, mounted on movable units, or both. The base frame orientations required for control are determined, and then control is established as described above. As an alternative to a modified indoor locator system approach, a machine vision approach may be used to track the tools directly in the stereoscopic images captured by the endoscopic camera. The tracking information is used to determine the pose of the end effector(s) directly in the reference frame associated with the camera's field of view. Referring toFIG.6A, machine vision processor626transmits spatial data632about the end effector to control system652. The tracked relationships are used to determine the relative pose of the manipulator bases, which are stationary during telesurgery. In one implementation, machine vision is in continuous use to track the poses of the end effectors. In an alternate implementation, once the relationship between the manipulator bases has been determined from machine vision and kinematic information, the alignment between the end effectors can be determined based on kinematic information alone, and there is no need for further machine vision tracking. Referring toFIG.6A, control system652receives such kinematic data as spatial information654a-654cfrom patient-side units608a,608b, and618. This use of kinematic data reduces the computational load considerably over continuous machine vision tracking. In yet another alternative implementation, machine vision tracking is used at intervals (e.g., every 100 ms, every 1 s, etc.) to update the pose information, and this periodic update implementation is still a considerably smaller computational load over continuous machine vision tracking. As another alternative, a spatial determining system is based on optical fiber shape sensors integrated with cables associated with each unit. A cable interconnection between units, or between two units and a common node such as the control system unit, includes an optical fiber shape sensor (e.g., one that incorporates fiber Bragg grating technology). The shape sensor technology is used to determine the spatial relationship between the interconnected units. Cables that transmit control or video data may be modified to include optical fiber shape sensors. The aspects above may be used to determine full pose information (full orientation and position information), or they may be used to determine less than full pose information (e.g., in a three-dimensional Cartesian space, partial orientation information around only one or two Cartesian axes and/or partial position information along only one or two Cartesian axes). As discussed above, in various embodiments including for many manipulator assembly implementations at the patient side, only the relative orientations between the camera and one or more tools is required for effective control alignment relating the tools to the camera. And so, only the relative orientations between these objects or individual links in kinematic chains that support these objects are required. Likewise, for user control in some embodiments, only the relative orientations between the displayed image of an end effector and a master device are required. Consequently, these aspects can be simplified or made more robust, because they need only estimate half the number of variables (i.e., orientation, and not position). If the need to determine and track full pose information is eliminated, and only orientation information is determined, then additional spatial determination methods are available. In one alternative orientation determining approach, spatial indicators656a-656fillustrate a 3-axis accelerometer and a 3-axis magnetometer combination. It will be recalled that the spatial indicators may be located at any link in a movable unit, or on an object itself, such as on an endoscopic camera. As shown inFIG.6B, for example, spatial indicators656a,656bare each a combination of a 3-axis accelerometer and a 3-axis magnetometer mounted to corresponding bases606a,606b. The combinations of both spatial indicators656a,656beach determine gravity vector g and bearing with respect to the earth's magnetic north N, and so they are constant for the two units. As shown, for the local magnetic field670, b is the local magnetic field vector, g is the gravity vector, and the bearing {circumflex over (b)} is the magnetic field projected onto a plane672perpendicular to g to indicate magnetic north. n=g×b {circumflex over (b)}=n×g From the magnetic north bearing, the gravity vector bearing, and kinematic information, the spatial orientations of the corresponding bases606a,606bare determined, and so the relative spatial orientations of the corresponding end effectors603a,603are determined for the initial alignment relationship. Likewise for FOV612and user control units. Then, once the initial control alignment is established, kinematic information may be used to provide full pose information for master/slave teleoperation. There may be a magnetic field disturbance in the operating room environment due to local magnetic materials, electric motors, electromagnetic field generators, nearby ferrous materials, etc. In general, the patient-side units should be placed so that the accelerometer/magnetometer combinations are away from these things. If the north bearing errors cause discrepancies in the north bearings for two or more patient-side units that are large enough to cause the initial alignment between the units to affect intuitive master/slave control, however, an alignment correction is necessary. For instance, identical motions of the left and right master input devices may result in different motions of their corresponding end effectors (e.g., the left end effector moves directly left as viewed in the display when the associated left master is moved directly to the left, but the right end effector moves up and to the left as viewed in the display when the associated right master is moved in the same direction directly left). Therefore, an alignment adjustment function is provided, and the user may adjust and fine tune the relation of the image of each tool with respect to the perceived orientation of the corresponding master device. Since the orientation misalignment is due only to different determined north bearings, this adjustment is a one DOF adjustment for each tool with respect to the FOV frame. As shown inFIG.6C, for example, a first bearingis determined for a first patient-side unit base reference frame674a, and a second bearingis determined for a second patient-side unit base reference frame674b. Since the bearings are different, the user may adjust the angle θ as shown between them in order to obtain an alignment for intuitive control. In this way, identical motions of the master input devices (e.g., directly to the left as perceived by the user) will result in identical motions of the corresponding tools (e.g., directly to the left as viewed in the display). This one DOF adjustment is much easier for the user to make as compared to adjusting an entire 3D rotation to make the correction, and it illustrates that this one DOF adjustment approach may be applied to any spatial determining approach for orientation in which one rotational alignment produces a non-intuitive control relationship. This may occur, for example, if a support structure base is moved or if a person holding the endoscopic camera moves. An alternative way of making the rotational correction is to use external tracking or machine vision approaches as described above to determine the misalignment, and the determined misalignment is used to make the correction. As described above, these correction approaches may be done at intervals to reduce computational load. Further, the combination of the accelerometer/magnetometer approach and a second spatial determining approach offers a more robust and computationally less demanding solution because the second approach is simplified as it determines orientation in a single DOF. For example, an accelerometer/magnetometer approach may be used to provide an initial estimation of a tool end effector orientation in an endoscopic camera field of view, and then by using this initial estimation a machine vision tracking task can be sped up or made computationally less demanding. As another alternative spatial determining approach, a 3-axis gyroscope is coupled in a fixed position to each unit. Each gyroscope is calibrated to a known orientation, and then the gyroscopes are used to determine subsequent orientations as the units are moved. Calibration may be accomplished in various ways, such as a known mechanical alignment (e.g., a fixture on the wall or table such as a surgical table) or by using the accelerometer/magnetometer approach as described above. Although gyroscopes may have a tendency to drift over an extended time, a gyroscopic approach may be combined with another spatial determining approach to provide a redundant incremental check on base orientations during use (e.g. during surgery in surgical examples). For example, accelerometer, magnetometer, and gyroscope measurements may be used together to determine relative orientations and transformations between base links. As another example, gyroscope measurements may be combined with other spatial determining methods to add robustness and redundancy, and to simplify or speed up estimations. In addition, gyroscopes may be used to detect transient disturbances in the magnetic field that cause a deflection of a bearing measurement that does not agree with the gyroscope data. In this aspect, gyroscope data is optionally more heavily weighted until the magnetometer signal stabilizes. Or, the detection of a transient magnetic field disturbance may be used to signal a problem or fault to the user. A single DOF adjustment to allow the user to fine tune the perceived alignment in a reduced parameter space as described above may be incorporated into implementations that incorporate gyroscopic information. As another alternative spatial determining approach, only acceleration sensors are used, and vibration sensors (see e.g.,FIG.6, sensors624a-624cincluding vibration sensing/injecting units) are used to determine relative spatial relationships between units. In one implementation, ambient common mode vibration (e.g., from the floor) is sensed at each patient side unit or cannula. Assuming the same ambient vibration is sensed by each unit, a common mode signal is identified by accelerometers associated with and fixed at known orientations to each unit. The gravity vector and sensed horizontal directions of the vibrations at each unit are used to determine relative orientation between units. In an alternative implementation, a common mode vibration is injected. For example, a cannula is vibrated so that its remote center of motion at the body wall vibrates in a known direction. The injected vibration directions are sensed by the units, and the relative spatial orientation is determined. In yet another implementation that uses vibration information, one or more beacons are placed (e.g., on the operating room floor) to inject periodic and time-synchronized common mode vibrations so that each unit can sense the vibrations. Accelerometers or matched resonators on the units sense the vibration. Time of flight measurement is used to establish distance to the vibrating beacon or beacons, and triangulation is used to determine the relative spatial orientation of the units. For example, assuming speed of sound in concrete is 3500 m/s, a 1 cm resolution requires ˜3 μs time resolution. This approach advantageously eliminates the need for a clear line-of-sight between beacon and sensor. In all approaches that incorporate vibration injection, vibration frequency may be selected outside the audible range. In another implementation, orientation degrees of freedom are optionally measured by using two or more different approaches. For example, an accelerometer may be used to determine orientation in two axes and machine vision is used to determine a bearing orientation in the remaining axis. The determinations are fused, and the fused result provides the complete 3-axis solution. Thus a spatial determining system is used to determine the relative orientations and required transformations between multiple teleoperated system units in order to establish and maintain the required user's intuitive perception of control alignment between hand-operated master control devices and corresponding tools. Advantageously, only orientation information is used to establish and maintain the alignments required for master/slave control, or orientation information combined with less than complete position information is used to establish and maintain the alignments required for master/slave control. 5. Further Implementations Many implementations have been described in terms of a telesurgical system, but it should be understood that inventive aspects are not limited to telesurgical systems. Implementations in various other teleoperated systems are contemplated. For example, aspects may be implemented in teleoperated systems with military applications (e.g., bomb disposal, reconnaissance, operations under enemy fire), research applications (e.g., marine submersibles, earth-orbiting satellites and manned stations), material handling applications (e.g., nuclear “hot cell” or other hazardous materials), emergency response (e.g., search and rescue, firefighting, nuclear reactor investigation), unmanned ground vehicles (e.g., agricultural, manufacturing, mining, construction), and the like.

11857281

DETAILED DESCRIPTION The foregoing is a summary, and thus, necessarily limited in detail. The above-mentioned aspects, as well as other aspects, features, and advantages of the present technology will now be described in connection with various embodiments. The inclusion of the following embodiments is not intended to limit the invention to these embodiments, but rather to enable any person skilled in the art to make and use this invention. Other embodiments may be utilized and modifications may be made without departing from the spirit or scope of the subject matter presented herein. Aspects of the disclosure, as described and illustrated herein, can be arranged, combined, modified, and designed in a variety of different formulations, all of which are explicitly contemplated and form part of this disclosure. Unless otherwise defined, each technical or scientific term used herein has the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. As used in the description and claims, the singular form “a”, “an” and “the” include both singular and plural references unless the context clearly dictates otherwise. For example, the term “an EM sensor” may include, and is contemplated to include, a plurality of EM sensors. At times, the claims and disclosure may include terms such as “a plurality,” “one or more,” or “at least one;” however, the absence of such terms is not intended to mean, and should not be interpreted to mean, that a plurality is not conceived. The term “about” or “approximately,” when used before a numerical designation or range, indicates approximations which may vary by (+) or (−) 5%, 1% or 0.1%. All numerical ranges provided herein are inclusive of the stated start and end numbers. The term “substantially” indicates mostly (i.e., greater than 50%) or essentially all of a substance, feature, or element. The terms “connected” and “coupled” are used herein to describe a relationship between two elements. The term “connected” indicates that the two elements are physically and directly joined to each other. The term “coupled” indicates that the two elements are physically linked, either directly or through one or more elements positioned therebetween. “Electrically coupled” or “communicatively coupled” indicates that two elements are in wired or wireless communication with one another such that signals can be transmitted and received between the elements. As used herein, the term “comprising” or “comprises” is intended to mean that the device, system, or method includes the recited elements, and may additionally include any other elements. “Consisting essentially of” shall mean that the device, system, or method includes the recited elements and excludes other elements of essential significance to the combination for the stated purpose. Thus, a device, system, or method consisting essentially of the elements as defined herein would not exclude other elements that do not materially affect the basic and novel characteristic(s) of the claimed invention. “Consisting of” shall mean that the device, system, or method includes the recited elements and excludes anything more than trivial or inconsequential elements. Embodiments defined by each of these transitional terms are within the scope of this disclosure. Disclosed herein are robot-assisted, image-guided instrument driving systems and methods for navigating a medical instrument through an anatomical three-dimensional space where no direct line of sight is available to a medical practitioner. As shown inFIG.1, in various embodiments, the instrument driving system10includes an imaging subsystem16, a tracking subsystem36, a user workstation31, an instrument driver22, and a controller34. Each of these elements and subsystems is discussed in detail below. With these elements and subsystems, the instrument driving system10is configured to assist in navigating a medical instrument18(not shown inFIG.1) to a target location in a three-dimensional anatomical space. In various embodiments, the medical instrument18is a flexible and/or elongate medical device or any other tool that may be inserted into a body lumen. As non-limiting examples, the instrument may be a catheter, sheath, leader, probe, biopsy needle, aspiration tool, endoscope, optical fiber, guidewire, tool for delivering or implanting a stent or valve, surgical tool, imaging tool, diagnostic tool, and/or therapeutic tool. In various embodiments, the medical instrument is robotically controlled. “Medical instrument,” “elongate instrument,” and “flexible instrument” are used interchangeably herein to refer generally to any robotically controlled instrument18configured for insertion into an anatomical lumen. In some embodiments, the medical instrument includes a flexible inner member and a tubular outer member. In some embodiments, the flexible inner member is a guidewire and the tubular outer member is a leader catheter. In other embodiments, the flexible inner member is a leader catheter and the tubular outer member is a sheath catheter. In still other embodiments, the flexible inner member is a guidewire and the tubular outer member is a sheath catheter. In some embodiments, a guidewire, leader catheter, and sheath catheter are provided. In various embodiments, the elongate instruments18have one or more controllable bending sections or articulation sections. The bending sections are manipulatable to change the direction of the tip of the flexible instruments as they are being advanced into the patient. The deflection or bending of the tip is sometimes referred to as the “articulation angle” and the corresponding tip direction is sometimes referred to as the “heading direction”. The bending section may be configured to bend directly in multiple planes relative to its non-articulated state, or it may be configured to first bend in one plane and be rotatable or rollable to reach another plane. The rotational orientation of the bending section is sometimes referred to as the “roll angle” or the “roll plane”. In various embodiments, the elongate instrument18has a proximal portion and a distal portion. The terms “proximal” and “distal” are relational terms defined from the frame of reference of a clinician or robot arm. The proximal portion is configured to be positioned closer to the clinician or robot arm and the distal portion is configured to be positioned closer to the patient or advanced further into the patient. In various embodiments, the anatomical space is a three-dimensional portion of a patient's vasculature, tracheobronchial airways, urinary tract, gastrointestinal tract, or any organ or space accessed via such lumens. Images of the anatomical space may be acquired using any suitable imaging subsystem16. Suitable imaging subsystems16include, for example, X-ray, fluoroscopy, CT, PET, PET-CT, CT angiography, Cone-Beam CT, 3DRA, single-photon emission computed tomography (SPECT), MRI, Optical Coherence Tomography (OCT), and ultrasound. One or both of pre-procedural and intra-procedural images may be acquired. In some embodiments, the pre-procedural and/or intra-procedural images are acquired using a C-arm fluoroscope, such as described in U.S. Pat. No. 8,929,631, the disclosure of which is herein incorporated by reference in its entirety. In the following discussion, the image and image acquiring device (i.e., the imager) are often referred to using the terms “fluoroscopy image” and “C-arm,” respectively, but the invention is not limited to use with fluoroscopy images; the same techniques apply to a variety of imaging subsystems. In various embodiments, the tracking subsystem36tracks the medical instrument18as the medical instrument18progresses through the anatomical space. As used herein, a tracking subsystem36may also be referred to as a position tracking system, a shape tracking system, or a localization subsystem. The term “localization” is used in the art in reference to systems and methods for determining and/or monitoring the position (i.e., location and/or orientation) of objects, such as medical instruments or tools in a reference coordinate system. Any suitable tracking system may be used. In many embodiments, the tracking subsystem36includes one or more sensors placed on or in the medical instrument18to enable tracking of the instrument18. The tracking subsystem36further includes a computerized tracking device configured to detect the one or more sensors and/or receive data from the one or more sensors. In some embodiments provided herein, an electromagnetic (EM) sensing coil system is used. In other embodiments, a fiber optic tracking system or other tracking or localization system is used. The tracking sensor or localization sensor is often referred to herein as an EM sensor to avoid listing numerous sensors for each embodiment, but it should be emphasized that any tracking or localization sensor, including a fiber optic sensor, may be used. A “sensed” medical instrument, as used at times herein, refers to an instrument that has a position tracking sensor embedded therein and is being tracked. A “localized” medical instrument, as used at times herein, refers to a sensed instrument that has been localized to a reference coordinate system. As described in more detail further below, in some embodiments, the reference coordinate system may be an image of the patient or a part of the patient anatomy. FIG.2provides one embodiment of an operating room setup that includes the robotically-assisted instrument driving system10. The depicted system10includes a table12upon which a patient14may be placed, a fluoroscopy system or other imaging subsystem16, and a catheter or other medical instrument18. The depicted fluoroscopy system16includes a C-arm28. A fluoroscopy panel30is mounted to the C-arm28. The C-arm28is selectively moveable during the procedure to permit various images of the patient to be taken by the fluoroscopy panel30. Attached to the table12is a robotic arm (also referred to as a setup joint)20to which a robotic instrument driver22is coupled. One or more splayers24may be mounted to the instrument driver22. In some embodiments, the splayers24are coupled to or form a portion of the medical instrument18. The medical instrument18of some embodiments also includes one or more pullwires disposed therein. The pullwires are attached to an articulation section of the medical instrument18and extend along a length of the instrument18to a proximal end. In such embodiments, the splayers24are positioned at the proximal end of the instrument18. Each of the splayers24may include a pulley about which one of the pullwires is wound and an interface for coupling with the robotic instrument driver22. In some embodiments, the components are configured such that a motor in the robotic instrument driver22rotationally drives an output shaft, which rotates the pulley of the splayer24and thereby adjusts tension in the pullwire to articulate the articulation section of the medical instrument18. The various components of the robotically-assisted instrument driving system10are further visible inFIG.3. One or both of the user workstation31and the controller34may be remotely positioned (i.e., free of a physical connection) with respect to the table12. In some embodiments, one or both of the user workstation31and the controller34are positioned in a separate room than the table12. The user workstation31includes a computer, a control console having a user input device33, and a visual display35. The visual display35may be a touch screen, LCD screen, or any other suitable display configured to present one or more images to a user. The user input device33may include, but is not limited to, a multi-degree of freedom device having multiple joints and associated encoders. The user input device33may additionally or alternatively include a keyboard, joystick, buttons, switches, knobs, trackballs, touchscreen, or any other input devices suitable for receiving commands from, and interfacing with, a user. The controller34is a computing device. As shown inFIG.4, the controller34includes electronics, including a processor50, and memory52having instructions stored thereon. The instructions, when executed by the processor50, cause the processor50to perform various controls methods and execute various algorithms described elsewhere herein. The processor50may be a general purpose microprocessor, a digital signal processor (DSP), a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), or other programmable logic device, or other discrete computer-executable components designed to perform the functions described herein. The processor50may also be formed of a combination of processing units, for example, a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other suitable configuration. The processor50is coupled, via one or more buses, to the memory52in order for the processor50to read information from and write information to the memory52. The processor50may additionally or alternatively contain memory52. The memory52can include, for example, processor cache. The memory52may be any suitable computer-readable medium that stores computer-readable instructions for execution by computer-executable components. For example, the computer-readable instructions may be stored on one or a combination of RAM, ROM, flash memory, EEPROM, hard disk drive, solid state drive, or any other suitable device. In various embodiments, the computer-readable instructions include application software stored in a non-transitory format. The software, when executed by the processor50, causes the processor50to perform one or more operations described elsewhere herein. The controller34further includes one or more interfaces54(e.g., communication databuses or network interfaces) for receiving user inputs from the user input device33, transmitting images to the visual display35, and transmitting commands to the robotic instrument driver22. In some embodiments, the controller34is configured for bidirectional communication with the robotic instrument driver22, enabling the controller34to receive torque data or other feedback from the instrument driver22. In some embodiments, the controller34is physically coupled to the user input device33and/or visual display35of the user workstation31. In some embodiments, the controller34is physically coupled to the robotic instrument driver22. In other embodiments, the controller34is physically separate from, but communicatively coupled to the user workstation31and the robotic instrument driver22via a wireless connection. A communication link32transfers signals between the user workstation31, the controller34, and the robotic instrument driver22. The communication link32may be a wired or wireless communication link. Each element of the robotic surgical system10positioned within the operating suite may define a separate reference frame to which localization sensors may be localized. More specifically, separate reference frames may be defined for each element of the robotic surgical system10. Such reference frames may include, for example, the following shown inFIG.2: a table reference frame TRF for the table12, a setup joint reference frame SJF for the setup joint or arm20, a robotic instrument driver reference frame RRF for the robotic instrument driver22, a splayer reference frame SRF for the splayer24, and a fluoroscopy reference frame FF for the fluoroscopy panel30. Additional reference frames that may be defined in the system include: a patient reference frame PRR for the patient14, a reference frame FRF for a tracking sensor disposed in or on the elongate instrument18, and a pre-operative 3-D anatomical model reference frame AMF for the model depicted on the visual display35. In various embodiments, the robotic surgical system10is designed to relate a coordinate system of the tracking sensor FRF of the elongate member18to either a fluoroscopy coordinate system FF or a pre-operative 3-D coordinate system AMF, as shown inFIG.5. The robotic surgical system10may employ a variety of registration techniques to register the FRF to the FF or AMF, such as those described below or those described in U.S. Pat. No. 9,014,851 to Wong et al., the disclosure of which is herein incorporated by reference in its entirety. In various embodiments, the position or shape tracking sensors incorporated into the medical instrument18allow for real-time sensing of the instrument's position (i.e., location, orientation, and/or shape). When the tracking sensor is integrated into the elongate instrument18and localized or registered to the anatomy or an image or model of the anatomy such that the position of the elongate instrument18is known relative to the anatomy, image, or model, a positionally-accurate representation of the instrument can be provided in the coordinate frame of the anatomical image or model. As the instrument18moves through the patient, the tracking information of the sensor can be used to update the position of the elongate instrument18relative to the anatomy, image, or model such that the representation of the elongate instrument can be displayed moving in real-time in an anatomical image or model. Additionally, with the instrument and the anatomical images provided in the same frame of reference, a target anatomy may be identified in multiple fluoroscopy views to localize the target's position in three dimensional (3-D) space relative to the elongate instrument. An aspect of the disclosure provided herein is to make use of this situation where the 3-D position of an instrument and a target are known in real-time relative to a user's view of the patient's anatomy in order to allow for novel navigation strategies not possible with traditional robotic or manual minimally-invasive instrument navigation. Robotic assisted driving, as provided herein, enhances the capabilities of an instrument control or tracking system by allowing a user to easily navigate the instrument through the complex anatomy to a target location without exposing the patient to excessive radiation during the procedure. One method of performing robotic-assisted navigation is provided inFIG.6. The method600is performed by a robotically-assisted instrument driving system, for example, the instrument driving system ofFIGS.1-4. In various embodiments, such a method600is performed by the robotically-assisted instrument driving system10in response to execution of the instructions stored in the memory52of the controller34. As shown in the depicted embodiment at S610, in some embodiments, the instrument driving system acquires and displays two images of a relevant anatomy at different viewing angles. The images are acquired by the imaging subsystem, and any suitable imaging modality may be used. As shown at S620, in some embodiments, the system localizes and displays the position of an elongate medical instrument relative to the images of the patient's anatomy. In some embodiments, this step includes acquiring localization information for the instrument from a tracking sensor disposed in or on the instrument, tracking the position of at least a portion of the medical instrument using a tracking subsystem, correlating the position of the instrument to the patient's anatomy, and superimposing a positionally-accurate representation of the instrument on the two displayed images of the anatomy. As shown at S630, in some embodiments, the system receives a user designation of an anatomical target in both images. The designation of the anatomical target in both images may be combined to compute a 3-D position (i.e., location, orientation, and/or shape) of an anatomical target. As shown at S640, in some embodiments, the system calculates one movement or a series of movements required for the instrument to move from its current position toward, to, or through the target. This calculation can be done continuously as the instrument moves through the anatomy or on-demand after a specific event or action is taken by the user. In some embodiments, these calculations are computed for multiple instrument components simultaneously (for example, for an inner member and an outer member). In various embodiments, the calculated movements include one or more of a magnitude and direction of articulation (e.g., a bend and a roll). In some embodiments, the calculated movements further include one or more of a magnitude and direction of axial translation of one or more instrument components (e.g., the inner member). As shown at S650, in some embodiments, the system utilizes the calculated movements to provide navigation assistance. The form of navigation assistance that is provided may vary widely between embodiments and/or modes. For example, the navigation assistance may include: providing step-by-step navigation instructions to the user, controlling navigation in one or more degrees of freedom, rejecting user-commanded movements that would navigate the instrument away from the target, driving the instrument towards the target while an auto-pilot indicator is actuated by the user, and/or driving the instrument to the target in a fully-automated manner. Each element of the assisted-driving method and the components that make it possible are described in more detail below. Tracking Sensors In various embodiments, at least one tracking sensor is incorporated into the medical instrument to enable detection of the position (i.e., location, orientation, and/or shape) of the medical instrument. In some embodiments, at least one tracking sensor is integrated into a flexible inner member of a medical instrument; in some embodiments, at least one tracking sensor is additionally or alternatively integrated into a tubular outer member of the medical instrument. For example, in the embodiment ofFIG.7, EM sensors are incorporated into the various components of the elongate instrument700. While numbered uniquely, one skilled in the art will appreciate that the medical instrument18ofFIG.1may be formed of any embodiment of an instrument described herein and may include any of or all the features of the instrument700shown inFIG.7. In the depicted embodiment, the medical instrument700includes an outer sheath catheter710, an inner leader catheter720, and a guidewire730. The sheath catheter710and leader catheter720each have a flexible distal portion, referred to herein as the articulation section716,726, and a stiffer proximal portion, referred to herein as the shaft712,722. Two five-degree of freedom (DOF) sensors714are located at the base of the sheath articulation section716, two 5-DOF sensors724are located at the base of the leader articulation section726, and a single 5-DOF sensor734is located at or near the tip of the guidewire730. The two EM sensors in each of the sheath and the leader form a pair of sensor coils in each instrument. These pairs of 5-DOF sensors enable tracking of each of the leader720and the sheath710in 6-DOF so that complete orientation, location, and heading are known. In the depicted embodiment of the guidewire730, there is only enough space for a single 5-DOF sensor734. In such embodiments, the guidewire position and direction are sensed, but not the roll. Combining two 5-DOF sensors into a single 6-DOF measurement (essentially calculating the roll angle of the instrument) can be accomplished in a number of ways. In one embodiment, two 5-DOF coils804are combined into a rigid assembly in a medical instrument800with known sensor locations and with the two coils804configured to have different orientations of their symmetric axes806, as shown, for example, inFIG.8A. This provides a strong or accurate 6-DOF measurement because the EM sensing technology is well-suited for sensing the heading, or symmetric axis, of the coils. There is, however, often inadequate space to place two nonparallel coils into an elongate instrument such as a catheter. In some embodiments, this limitation is overcome by spiraling the coils814around a perimeter of the tubular elongate instrument810, with a first coil spiral814atilted slightly relative to a second coil spiral814bwithin the wall of the instrument800, as shown, for example, in the cross-section ofFIG.8B. Such a configuration requires an elongate instrument with a relatively thick sidewall. An alternative embodiment places two coils824nominally parallel in the elongate instrument820to achieve the 6-DOF measurement, as shown inFIG.8C. In some embodiments, the coils824are positioned diametrically opposite each other across a cross-section of the elongate instrument820, because changes in the relative position of the coils can be more accurately determined with increased separation. In some embodiments, the coils are positioned off-center (i.e., less than 180 degrees away from each other) due to the design of the elongate instrument. For example, inFIG.8D, the placement of the central lumen832and pullwires833in the elongate instrument830creates a non-uniformly thick sidewall831, limiting placement of the coils834to thicker portions of the sidewall. In some embodiments, such as inFIG.8C, the coils824are parallel in both their orientation (e.g., axial alignment) and their position along the length of the elongate instrument820. With two parallel coils, combined sensor measurement and specifically the roll direction can be calculated by taking the difference in position between the two coil measurements. In some embodiments, the coils844may not be placed perfectly parallel along the length of the elongate instrument due to manufacturing tolerances, as shown, for example, inFIG.8E. In some embodiments, the math to generate the 6-DOF measurement includes the following, with reference made toFIG.8E. First, a primary sensor844ais used to find the point B′, which is axially in line with a secondary sensor844band directly perpendicular to the orientation of the primary sensor844a. The vector from A to B′ defines the roll direction of the sensor coordinate frame. A position of the “combined sensor” can be computed as the midpoint of vector A->B′ if the sensors are embedded in diametrically opposing locations of the instrument wall. If the sensors are not centered around the instrument shaft, as inFIG.8D, the relationship between the two sensors may be taken into consideration to adjust the position of the combined sensor. In some embodiments, the heading orientation of the combined sensor is determined either by taking the heading of the primary sensor (H A) or by averaging H A with the heading of the secondary sensor (H B). This method may cause a significant amount of roll error because the EM sensor measurements tend to have some error in their heading direction, and these errors are combined when producing the roll angle. Accordingly, to address this issue, in some embodiments, a low-pass filter is applied on the roll measurements. Elongate instruments in a body lumen generally do not roll very often or very quickly, so use of a low-pass filter does not significantly impact use of the elongate instrument or sensors. The low-pass filter does stabilize any display of sensor data that takes into consideration the roll information. In an alternative embodiment, a hybrid method is used in which both the slight variations in heading between the coils and the difference in position of the coils is used to calculate the roll direction independently and then combined. In some catheter embodiments, for example, inFIG.7, the EM sensor pairs provide position (x, y, z), heading (pitch and yaw), and roll orientation of the sheath and leader articulation sections. The EM sensor pairs may have any of the configurations described with regards toFIGS.8A-8E, or any other suitable configurations. Additional electromagnetic sensors may be added to different positions within the medical instrument to provide more information on the shape of the instrument. Registration Registration is a process that requires relating the reference frame of the sensor FRF to another reference frame of interest. If the positions of two or more objects are known in the same reference frame (i.e., are mapped to the same coordinate system), then the actual positions of each object relative to each other may be ascertained. Thus, with this information, a user can drive or manipulate one of the objects relative to the other objects. In various embodiments, the sensor reference frame FRF is registered to the fluoroscopy reference frame FF or to the fluoroscopic image or anatomical model AMF using a known registration technique. There are many ways this registration can be performed. In some embodiments, the sensor of the medical instrument is measured in relation to the fluoroscopy system frame of reference FF. For example, in some embodiments, a sensing probe is used, which has an EM sensor and a radiopaque marker located in the same physical location on the probe. The sensing probe is placed into the field of view. The 2-D position of the probe is designated by the user in the fluoroscopy field of view (FOV) in images obtained at two different C-arm roll angles. The position of the probe may be designated by the user in three or more different locations. These measurements are then used to sync the sensor location measurements with the selected fluoroscopy locations. In this way, the EM coordinate system is registered to the fluoroscopy coordinate system FF. In most interventional procedures, the reference frame of interest is the visualization frame. The visualization frame is the frame that the user (e.g., a physician) is viewing, and it may include a patient or a live 2-D or 3-D image. The live image may be acquired via fluoroscopy, ultrasound, digital subtraction angiography, live fluoroscopy with a contrast injection into the bloodstream, or other live imaging source. Using such techniques, the goal of registration is to determine the relationship of the frame of reference of the sensor FRF relative to the frame of reference of the patient PRF or to a 2-D or 3-D image or model of the patient. Virtual Instrument Various methods of tracking and registering the elongate flexible instrument are described above. In various embodiments, once an anatomical image is acquired, the sensor on the elongate instrument is tracked, and the sensor's frame of reference is registered to the anatomical image's frame of reference, a representation of the elongate instrument is displayed on the anatomical image to facilitate a user's ability to visually track progress of the elongate instrument in the anatomy. The process for displaying the elongate instrument on the image will now be described. The tracked instrument is simulated by rendering it with 3-D computer graphics and displaying, overlaying, or superimposing it on stored fluoroscopy images. One example of a simulated rendering of an elongate instrument920superimposed over the anatomy910captured in a stored fluoroscopy image900is provided inFIG.9. This simulated elongate instrument920is known as the virtual instrument or the virtual catheter. In some embodiments, the location, orientation, and shape of the virtual instrument920are estimated based on commanded data. In some embodiments, sensor measurements are used to improve the quality of the simulation and generate more accurate instrument shapes that are usable in clinical settings. In such embodiments, one or more of the location, orientation, and shape of the virtual instrument920is determined with the aid of tracking sensors. The current locations and orientations of the tracking sensors in an anatomical space are known from received sensor measurements. The fixed location and orientation of the sensors in each elongate instrument are also known. From these known data points, a virtual instrument920can be drawn that passes through these points. The total lengths and insertion distances of the various components of the elongate instrument are also known. Robotic movements of each component are tracked and this movement can be used to extrapolate the instrument shape between the sensor positions. The rotational orientation of the elongate instrument may also be determined from the sensors as described above to provide an entire 3-D reconstruction of the elongate instrument. One method for displaying the virtual instrument involves using spline curves to interpolate the shape of the elongate instrument between sensors. This method is purely geometric and therefore does not capture the characteristic behavior of a real instrument. Another method involves using a physics-based simulation to model an elongate instrument. In one embodiment, an instrument model comprises a series of points connected such that they maintain realistic positions relative to one another. The virtual instrument seen by the user is rendered as a 3-D object that follows a path through the series of points. In some embodiments, this virtual instrument information may be displayed to the user to help the user navigate. For example, instinctiveness indicators930such as the ring with colored cones shown inFIG.9may be added to the virtual instrument920and used to signal to the user which direction the instrument will bend when a specific user input command is activated. In the provided embodiment, the directional cones are on opposing sides of the ring (i.e., 180 degrees apart). Directional indicators of any distinguishing colors or shapes may be used. In some such embodiments, corresponding directional indicators may be placed on the user input device. The virtual directional indicators are continuously updated with the position of the elongate instrument to represent the direction the instrument would bend if the corresponding directional indicator on the user input device is activated. For example, in one embodiment, a ring is provided around the virtual instrument920with an orange cone and an opposing purple cone. On the user input device, a left button or left side of the joystick may be marked with the orange mark. Activation in this direction would bend the elongate instrument in the direction of the orange indicator on screen. On the user input device, a right button or right side of the joystick may be marked with the purple mark, and activation in this direction would bend the elongate instrument 180° from the first direction. Such an embodiment provides for more instinctive driving than simple “right” and “left” activation buttons, because the elongate instrument may rotate as it is advanced through the anatomy and the viewing angle of the C-arm may also rotate so it cannot be assured that bending the instrument to the left with the input device would result in the instrument bending to the left in the viewing plane. The presence of the 6-DOF position tracking sensors in the tip of the instrument may be used to communicate the actual roll orientation of the instrument tip in the given viewing plane. In some embodiments of robotic assisted driving (described in more detail below), the colored cones on the ring (or other instinctiveness indicators) are augmented to include another shape or other indicator to indicate which direction the system recommends that the instrument be articulated to aim towards the target. In simulating telescoping catheters using a physics model, it is often advantageous to treat multiple catheters as a single elongated object as it requires less computation. However, this model does not accurately capture the interaction between the catheters, introducing unrealistic constraints in the simulation. For example, the model would be subject to a large amount of torque if it were to match sensor measurements exactly, because real catheters have room to slightly roll relative to each other. This often leads to instability in simulation. In order to resolve the issue, in some embodiments, the model may use only a subset of sensor measurements to reduce the risk of over constraining the model. For example, the roll measurement at the instrument tip may not be rigidly enforced. In another embodiment, the accuracy of the virtual instrument920may be improved by tracking the elongate instrument via computer vision in a fluoroscopy image. Computer vision techniques to track catheters have been described, for example, in US Publ. No. US2016/0228032, issued as U.S. Pat. No. 11,426,095 on Aug. 30, 2022 the disclosure of which is herein incorporated by reference. The similarity of the fluoroscopic instrument and the virtual instrument can be used to generate bias forces to move the physics model closer to the real instrument shape. In another embodiment, fiber optic shape sensing sensors may be used to estimate the shape of the virtual instrument. In a further embodiment, the commanded robotic instrument insertion length or the commanded angle and heading orientation of an instrument may be tracked and compared to measured instrument position and heading based on sensor data and the delta may be used to update the physics model accordingly. In some embodiments, a 3-D model of the anatomy is generated from pre-operative imaging, such as from a pre-op CT scan, and the instrument model interacts with the anatomy model to simulate instrument shape during a procedure. For example, in one embodiment, the intersection of the instrument shape with the geometric model of the anatomy produces forces that are included in the simulation of the instrument. In addition, the time history of sensor locations provides insight as to the shape of the anatomy or the possible shape of the instrument. As an instrument passes through blood vessels, the instrument will often straighten or deform the anatomical shape. By tracking the path of the instrument through the anatomy over time, the relative shape of the deformed vessels may be determined and both the instrument model and the anatomical model may be updated. Interpolated instrument shapes become less accurate in parts of the instrument far away from sensors. When the virtual instrument shape deviates from the actual shape, physicians may inadvertently act on the incorrect information. Therefore, in some embodiments presented herein, a measure of confidence is displayed for each section of the virtual instrument shape so that physicians can make informed decisions. This measurement of confidence is guided by a few principles: the closer to a sensor, the higher the confidence; the higher the curvature between sensors, the lower the confidence; the greater the difference between the known and measured sensor-to-sensor distance, the lower the confidence; and the greater the difference in sensor orientations, the lower the confidence. In some embodiments, the confidence measure in part of the virtual instrument is shown non-numerically. For example, in one embodiment, the degree of transparency in the virtual instrument920corresponds to the measure of confidence. Part of the instrument may be made fully transparent if the confidence is sufficiently low so that the questionable portion of the instrument is hidden from the user. Alternatively, low-confidence may be represented by changing the color or texture of a part of the instrument or by adding animation, such as flashing or scrolling texture. In another embodiment, a flashing icon, such as a radiation icon, may be displayed beside the fluoroscopy image to urge the use of fluoroscopy when the confidence falls below a threshold value. It may start flashing when confidence drops as a way of suggesting that the user use fluoroscopy to acquire an updated image of the anatomy and the instrument. Low-confidence portions of the virtual instrument may flash in time with the radiation icon to better associate low confidence with the need for fluoroscopy. Virtual Biplane In various embodiments provided herein, a visualization mode called a “virtual biplane” is provided. In a virtual biplane, the virtual instrument is overlaid on the standard primary image and also on a secondary reference view. The concept of a virtual biplane is introduced in US Publ. No. 2015/0223902, now abandoned, to Walker et al., the disclosure of which is herein incorporated by reference in its entirety. Displaying a representation of the instrument updated in real-time, overlaid on two different views of the anatomy is analogous to what a user would see in a biplane fluoroscopy system. However, as contemplated herein, the biplane view is not an actual live biplane view, but rather, a simulation of the sensed instrument superimposed on the anatomical images. Therefore, it is known as a virtual biplane mode. The catheter or instrument that is displayed, overlaid, or superimposed on the anatomical image is referred to as the “virtual instrument” or “virtual catheter” as described above. In the virtual biplane, the virtual instrument is depicted in two different views of the anatomical background. In some embodiments, both provided views utilize fluoroscopy. In some embodiments, the virtual biplane includes a first fluoroscopic view with an image of the sensed medical instrument overlaid or superimposed on top of the fluoroscopic view. This may be a live fluoroscopic view or a previously acquired fluoroscopic view. The commercially available fluoroscopic systems have the capability of acquiring and storing images. These images may then be displayed as reference images at any point during the procedure. The virtual biplane embodiment presented here also includes a second view, which may be a reference view, for example, a previously-acquired view obtained via fluoroscopy at a different angulation of the C-arm. In one embodiment, the first and second view may be shown at different magnifications. For example, the first view may show an image at a lower magnification so that more of the instrument and anatomy is seen to help the user understand the global position in the patient whereas the second view may be a zoomed in or magnified view of an area of interest, usually in a different projection from the first view. As the medical instrument is moved or manipulated through the patient, the tracking sensor in the instrument tracks its movement and the virtual instrument is updated in both views. This provides live 3D tracking of the instrument displayed against images of the anatomy. The position sensor information is registered to each image so that as the image changes (for example, due to a movement in the C-arm), the system can calculate where the sensor measurements line up with the updated image. At any point during the procedure, the user may change the anatomical images used for the virtual biplane. For example, if a physician is attempting to target a first vessel pointing directly anteriorly (i.e., toward the front of the patient), a lateral fluoroscopic projection might be preferred for at least one of the views so that the vessel is perpendicular to the viewing plane, whereas if a second vessel is pointing partly anterior but partly to the side of the patient, than the physician may wish to change over to a more oblique fluoroscopic projection. A problem with said overlays is that the reference image shows the vessel anatomy at a specific instant in time. If the physician introduces a very inflexible or rigid instrument, the anatomy is deformed, and if the patient moves on the table, the overlay is no longer aligned. If said deformation or misalignment is not corrected in the overlaid reference image, an imprecision or a discrepancy arises when the reference image is superimposed. This can lead to uncertainties in navigation during an intervention in which the overlay serves as a navigation aid. Therefore, in various embodiments, the physician is provided with the option of refreshing the image by taking another live image at any point during the procedure. In some embodiments, the images are acquired using a C-arm fluoroscope, with one viewing angle acquired prior to the procedure and the other viewing angle acquired intra-procedurally. In some embodiments, both views are displayed simultaneously, for example, adjacent to each other. In other embodiments, one or more of the images are generated by an imaging system that overlays a registered pre-operative or intra-operative 3-D image (e.g., 3-D rotational angiography or cone beam CT) on a live image. In still other embodiments, a pre-operative or intra-operative 3-D image is acquired and displayed, which is not registered or overlaid onto live imaging. An example of a virtual biplane is provided inFIGS.10A-10C. In some embodiments, two views are displayed on a split screen. In other embodiments, two display screens are provided, each displaying a different view. In the example images captured inFIGS.10A-10C, the left view directly corresponds to the C-arm angle. If the C-arm is rotated, then this view, including the depicted EM sensing information will change; as the C-arm moves, the EM indicators and virtual instrument will update according to that new C-arm angle. In some embodiments, if the user steps on the fluoro pedal of a fluoroscopic imaging subsystem, the image directly related to the C-arm angle will update based on the live fluoro image. In some such embodiments, if the user releases the fluoro pedal, the last image will be used as a reference image when driving an EM sensed instrument. In such embodiments, the fluoro image may get out of sync with the EM sensor data if the C-arm is rotated but the user is not stepping on fluoro. In such embodiments, a visual indicator may be presented to the user to indicate that the fluoro image is no longer relevant. For example, in some embodiments, the outdated fluoro image may be blackened or given a hue or color or icon to show that it is old information. In other embodiments, a sequence of fluoro images at different angles can be acquired and stored, possibly using a predefined C-arm motion to acquire them, and the reference image can be updated based on C-arm motion even when the user is not stepping on fluoro. In some embodiments of the virtual biplane, the second image is always a stored image associated with a particular angulation of the C-arm. The particular C-arm angulation is provided and used to allow the sensed instrument information to update live according to that stored view. In the embodiment ofFIGS.10A-10C, the right image is the stored reference image. The stored reference image is a fixed snapshot of a fluoro image taken sometime in the past, which corresponds to the particular C-arm angle. The user can use this stored background image as a reference or roadmap as they are driving. Different visual indicators may be used to show that this is a stored image, such as colors, hues, or icons. At any time, a button or other user input device can be selected to store the live image and C-arm angulation for use as the stored reference in the future. In some embodiments, it is possible to store multiple reference images each associated with a different respective C-arm angulation. A user or the system may be able to select between the multiple reference images and use different ones at different times without using additional radiation. For example, in some embodiments, the stored image consists of a sequence of images at different C-arm angles. In such embodiments, the sequence of images may be sequentially displayed as the C-arm moves even if the imaging is not live. Alternatively, in such embodiments, the displayed image selected from the sequence of images at different C-arm angles may be chosen by the user through a user interface that allows the user to modify the viewing angle of the second image. In other embodiments, the second image may automatically change to display images from various C-arm angles in a cyclic or periodic fashion providing an animation of the live EM information that provides the user with more three-dimensional information about the shape of the medical instrument or anatomy. In various embodiments, the images stored in the virtual biplane are often views directly from the fluoroscopy system or other imaging system. In some embodiments, it may also be possible to include overlays from the fluoroscopy system or other imaging system. Such a feature may be helpful in certain workflows, for example, when the user wants to do a contrast injection and store the image during a contrast injection or digital subtraction angiography (DSA) to show the anatomy of interest. The fluoro system may also be used to play back a run of fluoro in the image stored during that playback. In some embodiments, this system may also be used to capture a sequence of frames over the respiration cycle or pulse cycle and play back a video as a stored image instead of a static image. Alternatively, in some embodiments, the virtual biplane may include one or more renderings of the three-dimensional imaging of the anatomy such as a segmented CT or MM image or intraoperative cone beam CT, IVUS, or ultrasound. In some such embodiments, an image of the sensed medical instrument is placed within the three-dimensional rendering of the anatomy based on the registration of the medical instrument to the anatomical model. Multiple different registration methods may be used as described above and in U.S. Pat. No. 9,014,851, the disclosure of which is herein incorporated by reference in its entirety. Such embodiments provide multiple views for the user during navigation of the medical instrument without requiring live imaging. For example, the embodiments ofFIGS.11A-Beach shows a cone beam CT outline overlaid on a fluoro image or alone on a black background. Similar imagery can additionally or alternatively be created using imaging gathered preoperatively, such as from a CT or MM. In these and other embodiments, overlaying a representation of the 3-D anatomy (be it an outline, filled solid area, 3-D rendering, or composite of a stored fluoro image with 3-D imagery) on the background allows for the use of the 3-D data for guidance without additional fluoroscopy. This data can be interfaced with the navigation system through either: a data connection between the navigation system and the imaging system, or displaying frame grabbed video directly or composited with other imaging within the system. In other embodiments, two display screens or two portions of the same display screen show, from different perspectives, views of the three-dimensional anatomical model with a simulation of the sensed medical instrument positioned therein. In some embodiments, one of the displayed views is a simulated endoscopic view (also known as an “Endo View”), which provides the perspective of looking along the instrument or from the front of the instrument within the three-dimensional model of the anatomy. These or other views may supplement or form some of or all the virtual biplane. Selection of Targets As described elsewhere herein, an object of the present disclosure is to provide systems and methods for robotic assisted driving of a medical instrument to a target within an anatomical space. In addition to acquiring images of the anatomical space, sensing and tracking the medical instrument, registering the coordinate system (i.e., reference frame) of the medical instrument to the coordinate system of the images, and overlaying a representation of the medical instrument on the images, various methods of robotically assisted driving also require identification of the target. Together, the sensed information of the medical instrument and the identified location of a target can be combined to provide robotically-assisted driving modes. Various modes and embodiments of identifying the target are discussed in more detail below. In the provided discussion, “targets” are referred to in a generic sense and may refer to a target position, a heading, an ostium shape, or other element or elements of interest to navigation. The target is generally the 3-D center of an anatomical feature that the user would like to access, such as the ostium of a blood vessel coming off the aorta. While a blood vessel is frequently mentioned herein, a target could also correspond to a feature of an implanted device such as an aorta aneurysm endograft or a fenestrated graft. In some embodiments, a target may refer to an anatomical feature such as an ablation site, the annulus of a coronary valve, a suspect nodule or a tumor and may be within any lumen of the body including the airway, gastrointestinal tract, or other lumen or within any organ accessed via a body lumen. When no additional context is provided, “target” in this discussion refers to the three-dimensional position at the center of the entrance of the feature to or through which the user wants to navigate. In various embodiments, a target is designated in three-dimensional space via one or more user selections of the target position on multiple imaging views. In some embodiments, selection (i.e., designation) of the targets involves a user interaction telling the system where the targets are and how they are oriented. In other embodiments, the system automatically calculates where the targets would be based on known information such as a three-dimensional CT or other target locations, or a combination of both. The three-dimensional imagery may be acquired from a preoperative CT or via imaging during the procedure, such as via cone beam CT. The user may designate the target within an image using a variety of user input devices such as a mouse, trackball, buttons, joystick, or touchscreen. In some embodiments, the user manipulates a user input device to navigate a pointing device icon to the target in the displayed images. The user may further manipulate a user input device (for example, with a button push, mouse click, or finger tap) to select the target. In one embodiment, a trackball and buttons are used by the user to designate targets of interest. In other embodiments, other interfaces are utilized that also provide a means to identify and select points in the images, such as, but not limited to, a computer mouse, touchscreen, gesture device such as Xbox Kinect, joystick, etc. In some such embodiments, an interface allows the user to designate a position on a three-dimensional CT or other three-dimensional image and the system computes the target position, heading, ostium shape, vessel centerline, or other information useful for navigation. This interface may be at an operator workstation or may be positioned bedside or in any convenient location and may be designed to operate in a sterile or non-sterile environment based on the location chosen. In some embodiments, there may be multiple operator interfaces so that, for example, an assistant can choose the target locations at a remote workstation and the physician can continue the navigation bedside. In other embodiments, the imagery video from an imaging system, as shown for example inFIG.11B, may be frame grabbed by the system and then processed using computer vision techniques to determine anatomical features of interest to create targets or provide additional guidance as the user is creating the targets. For example, the system may detect body lumen edges based on pixel density and automatically compute the diameters and centerlines of the lumens within the two views; such a system may then allow the user to designate a single point in one image to identify the target position, heading, and ostium size using the anatomical data reconstructed from the imagery. In addition to the position of the target, it is useful to know the direction or orientation of the lumen beyond the entrance or ostium (i.e., distal to the target). This direction, or “heading”, can help the robotically-assisted instrument driving system identify the best approach to enter the lumen. When a user needs to navigate through a target, it is more complex than when a user needs to navigate to a target. Navigation to a target often does not require a specific angle of approach whereas navigation through a target often requires the medical instrument to be lined up squarely with the target before advancing through it. It is easier to enter a lumen if axially aligned with the heading of the lumen rather than positioned perpendicular to it. Therefore, navigation through a target requires an understanding of the anatomy distal to the target and so requires more information, usually at least a second point. In some embodiments, the heading is a single vector direction; in other embodiments, the heading may be a designated or computed lumen centerline. In some embodiments, the user designates a position on the 3-D image and the imaging system computes the shape and orientation of the target opening or the direction of the target lumen based on the 3-D geometry. In other embodiments, a user is prompted to designate the shape of the lumen entrance so that this entrance can be better shown within the user interface. In one embodiment, the target position, heading direction, and radius of the lumen are identified by the user within at least one of the anatomical views and used to create a circle in space centered at the target position and perpendicular to the heading direction. It is also possible to use multiple points on the edge of the ostium or other element of interest to define a more complex shape such as an ellipse or any other closed shape. The user may designate these points on the display screen. Alternatively, multiple points or line segments may be sufficient to designate and define the shape of a vessel entrance. One embodiment of selecting the target is shown inFIGS.10A-10C. In the depicted example, a user is shown inFIG.10Aselecting a target in a first image. The user may manipulate a user input device to navigate a set of crosshairs over the target. The user may also be able to manipulate the user input device to change the size of the crosshairs so as to approximate the size of the target. As shown inFIG.10B, once the target is selected in the first image, the system may determine a plane along which target is located, and a line projection may appear in the second image depicting the plane to facilitate target selection for the user. The user is shown inFIG.10Bmoving the crosshairs along the line projection and selecting the location of the target in the second image. As shown inFIG.10C, following user identification of the target, the target (or a perimeter of the target) remains illuminated to facilitate visualization of the target during instrument navigation. Instrument navigation is then depicted inFIG.10D. It is also possible to designate more than one target position (or heading or shape). As one example, different target positions are typically required for the inner and outer members of a medical instrument. A first target may be designated by a user, and a second target may be calculated based on the location, heading, or shape of the first target. For example, if the user identifies a target for the inner member, the system may automatically compute a separate target for the outer member. In some embodiments, the position of the separate target for the outer member is selected such that when the outer member is aligned with the outer member target, the inner member may be automatically or semi-automatically positioned to align with the inner member target. In some embodiments, the heading of the inner member target relative to the heading of the outer member tip or other part of the virtual instrument may be used to determine the distance of the outer member target from the inner member target. In some embodiments, the system takes into consideration the known articulation length of the inner member to determine the outer member target position or heading. In some embodiments, anatomical information from 3-D imaging, such as a pre-op CT, allows the system to better compute the outer member target by taking into consideration lumen walls when computing the optimal outer member distance from the final target. In some embodiments, 2-D anatomical information from one or more images may be used to determine the position of the outer member target by creating constraints in three-dimensional space from the projection of the 2-D anatomical information. In some embodiments, the user determines the outer member target based on the center line path from the 3-D dataset. In some embodiments, the system is configured to perform a method to modify the target after it is initially specified. For example, instead of setting a new target, the user may be able to use a mouse or other input device to move an existing target in 2-D or 3-D space. In one embodiment, the input device is used to move the target in a single image to fine tune its location in relation to the image or anatomy during navigation. In other embodiments, the system automatically fine tunes the target location based on other information such as 3-D imaging or other live intraoperative imaging such as IVUS. Separate targets for both inner and outer members (e.g., the sheath and leader catheters) may be similarly reconstructed in this fashion taking into consideration the anatomical shape. As an example, for a sharp vessel takeoff at an angle greater than 90°, such as the right renal vessel1504shown inFIGS.15A-E, the system may determine the best target for the inner and outer members taking into consideration the angle of approach, the size of the lumen proximal to the target, the takeoff direction of the sharp vessel, and the size of the lumen distal to the target. In some embodiments, targets may be marked within the 3-D imaging system making use of a registered pre-op CT, cone beam CT, or other imaging system. For example, the ostia of vessels may be marked in a 3-D volume as described in U.S. Pat. No. 9,256,940, the disclosure of which is herein incorporated by reference in its entirety. These marks may be exported directly to a flexible instrument navigation system (e.g., the Magellan® system by Hansen Medical Inc.). In this manner, physicians may use their familiar registration, segmentation, and marking toolset, and the data needed to improve navigation is exported to the navigation system as target or waypoint data. In one example, a trackball or other user input device is used to designate targets via the following sequence: (a) a pair of clicks, one in each of the two views of a virtual biplane, designate the target position for the inner member, (b) a pair of clicks, one in each of the two views of the virtual biplane, designate the target heading direction for the inner member; (c) one click on the heading line designates an outer member target position; and (d) one click designates the radius of the ostium (or the size of any other target). In some embodiments, a pair of clicks is required to designate a 3-D position of the target. After the first click on the first view (shown inFIG.10A), that click (or 2-D position in the screen space) defines a line of possible positions in 3-D space based on the camera projection. As shown inFIG.10B, that line is shown in the second view to aid in identifying the corresponding position of that feature in the alternate C-arm angulation. Once the two clicks are processed, the lines based on the camera projection are calculated and the closest point between those two lines is used for the 3-D target position. In other embodiments, when the heading direction of a target or anatomical feature needs to be defined as well as its 3D position, a second point on the target (referred to as the “heading position”) is required and it may be designated in much the same way as the target 3-D position. Two clicks of the anatomical feature distal to the target from two different views are processed to find the heading position on the anatomical feature, and the designated heading position is then used with the target position to calculate the heading direction. In some embodiments, a line corresponding to the possible heading is drawn before each point is clicked to help the user understand the possible heading positions. In other embodiments, with a first click, the user input device position is used to calculate the two-dimensional heading in the first image, and with a second click, the user input device position in the second image is used to calculate the three-dimensional heading based on the first two-dimensional heading in the first image. In some embodiments, the size of the target (e.g., the ostium radius) is calculated by using the closest distance between the line defined by the 2-D clicked point and the target position. Many other interfaces may be used to set the target size or shape. For example, multiple clicks around the edges of a target, as seen within 2-D space, may be used to define a size and shape of the target in one view and to identify the target in the other view. In another embodiment, the target radius is traced, for example, using a mouse or trackball. In another embodiment, the size of the target radius is varied as the user input device is moved up and down or left and right and is shown on the screen with a dotted line until the user appropriately actuates the input device (for example, with a click) to set the target size. Once the targets are designated, multiple icons can be used to show that the target is designated. For example, in some embodiments, such as shown inFIGS.10A-D, crosshairs or partial crosshairs may show where the target is, a line from the center of that target may show the heading of the lumen, a circle or other shape corresponding to the perimeter of a target may be highlighted, and/or a radar screen showing the positioning of the target within the radar may be provided. When the user switches the selection between different components of the instrument, for example, between leader and sheath catheters, different targets may be displayed in different places corresponding to the different members. Robotic Assisted Driving Once the current location of the medical instrument and the location of the target are known, the robotic driving system can help the user navigate. Various embodiments of advanced driving modes are discussed in more detail below. In some embodiments, the instrument driving system is configured to perform one of the disclosed advanced driving modes. In other embodiments, the instrument driving system is configured to perform some of or all the disclosed advanced driving modes. In such embodiments, the user may select the level of assistance or control the user wishes to hand over to the robotic system. In various embodiments provided herein, the one or more advanced driving modes are encoded for in software saved to memory within the controller34. The advanced driving modes are referred to herein as “robotic assisted driving” or “robotic assisted navigation” modes. In various embodiments provided herein, user commands to the instrument driving system can be augmented with additional robot-determined movements to accomplish navigating the medical instrument to or through the target. In some embodiments, it is most desirable to allow the robotic medical system to automatically command the articulation direction and articulation magnitude of the medical instrument to arrive at or travel through the target. In other embodiments, it may be desirable to allow the user to maintain at least some control over these motions while the robot assists. Therefore, there are various degrees of implementation of robotic assisted driving which are presented herein. In some embodiments, a computer-augmented driving mode is available to the user. When such a mode is selected, the user may control instrument translation (e.g., insertion and retraction), and while translation is occurring, the robotic system may automatically control articulation magnitude and direction (i.e., bend and roll) and provide additional movements of the instrument tip to help track the instrument to the target location. The automatic selection of the optimal articulation amount and roll direction by the controller prevents the user from needing to both perceive in three dimensions where the target is in relation to the instrument and determine the amount of bend and articulation needed to aim the instrument in that position in three dimensions. In a sense, the robotic instrument driving system (and specifically, the controller or control algorithm of the robotic system) can assist the user in navigation even if the system does not know how to control all degrees of freedom of the instrument to achieve the user's goal. In another computer-augmented driving mode or embodiment, the user navigates translation and one of articulation and roll, and the robotic system navigates the other of articulation and roll, as needed, to ensure the user-commanded movements lead the medical instrument to the intended location. The exact amount of help or movement provided by the system may vary depending on the application. One example of computer-augmented driving is depicted inFIGS.12A-B.FIG.12Aprovides a 2-D representation of an elongate instrument, as it would appear to a user within a first view of a virtual biplane.FIG.12Bprovides a 2-D representation of the elongate instrument from a different point of view, for example, as it may appear within a second view of the virtual biplane. In the depicted embodiment, the user's goal is to bend the virtual instrument1200(and the corresponding real instrument) towards the target1210located at the 9 o'clock position in the second view. As shown inFIG.12B, in the user's first attempt to navigate towards the target1210, the user inadvertently commanded articulation of the instrument towards 10 o'clock. In some such embodiments of augmented driving, as the user commands roll or rotation of the instrument to find the target1210, the system automatically updates the mapping of the rotation input from the user to the desired rotation and automatically rotates the instrument tip from the 10 o'clock position to the 9 o'clock position. Alternatively, rather than mapping a user input to the desired motion, the robotic system may augment the user inputs with additional motions to accomplish the tasks. For example, with the target1210designated at the 9 o'clock position, when the user commands articulation of the instrument, the robotic system automatically supplements the commanded articulation with a roll command to achieve the desired motion or navigate toward the target. Robotic assisted driving has been explained above as helping or augmenting user commands. Robotic assisted driving may also include identifying or automatically choosing movements such as the heading direction of the instrument. The controller34may use the position and/or heading of the instrument's articulation section and the location, shape, and/or heading of the target to automatically choose the preferred roll plane and articulation magnitude, for example, in order to reach the target or cannulate a target vessel most effectively. As discussed above, the exact implementation may vary based on the application and the user commands. For example, if the user is commanding a roll motion as inFIG.12B, then the automatic choosing of the preferred roll plane involves mapping the user input to a desired motion or adding additional robot-commanded movements to the user-commanded movements to direct the instrument tip towards the target. If the user is commanding an insertion motion, then the automatic choosing of the preferred roll plane includes augmenting the insertion motion with rotational movement to direct the instrument tip towards the target. Likewise, the automatic choosing of a preferred articulation magnitude may consist of mapping an articulation user-input command to a robot-determined desired articulation movement to thereby direct the instrument tip towards the target when the user commands articulation. Additionally or alternatively, robotic assisted driving may include supplementing an insertion motion with appropriate robot-determined articulation movements to direct the instrument tip towards the target. Additionally or alternatively, in some embodiments of robot assisted driving, the controller34commands the system to display a recommended path or shape of the instrument to the user. One example is provided inFIG.13. As depicted, the recommended path1310through the anatomy1300may be denoted with a hidden or dashed line or other suitable marking. The recommended path1310depicts an optimal or suitable path within the anatomical image for getting the virtual instrument1320from its current position to the target. Such a display allows the user to see how the instrument should be oriented. In some embodiments, the user can then control the instrument, using the path1310as a guide. In some such embodiments, the controller34is configured to suspend movement of the instrument and notify the user automatically if the instrument deviates from the recommended path. In another embodiment, the system may automatically reduce the insertion speed if the instrument has deviated from the path1310or if articulation has not yet reached a desired amount in order to minimize force on the anatomy. In alternative embodiments, the controller34may ensure that the instrument follows the recommended path by supplementing or adjusting the user-commanded movements with robot-determined course-correcting movements. In other embodiments, the controller34computes one or more insertion, articulation, and/or rotation movements needed to keep the instrument tip on the path1310. In some embodiments, the controller34commands the instrument driver22to execute motor actuations needed to implement the one or more movements. In some such embodiments, the controller34and the instrument driver22work together to drive the instrument along the recommended path1310while an auto-pilot feature of the user input device is actuated. In some such embodiments, the user must activate an input device in order to continue progress. At any time, the user may disengage the input device to stop all motion. The recommended path1310may be derived from anatomical information provided by the imaging subsystem. The anatomical information may take the form of a 3-D model of the anatomy, and the recommended path may equal the centerline of a segmented body lumen. In other embodiments, the anatomical information may be in a two-dimensional form such as frame grabbed images from the imaging subsystem. In some embodiments, the anatomical information is used to adjust the computed movements of the instrument as it navigates the anatomy by choosing articulation and roll values that keep the instrument away from the lumen walls. In some embodiments, the anatomical information allows the controller34to better determine when to insert one or more members of the instrument to achieve the best shape, maintain a sufficiently large distance away from the lumen wall, and/or enable the instrument to move in the lumen with minimal resistance. It can be important to provide feedback to the user to let the user know that the instrument is progressing correctly. In some embodiments, visual indicators are provided to help the user understand the relationship between the instrument and the targets and improve control over the instrument. Visual indicators may be provided to show that the target algorithm is converging on a solution and aiming the instrument towards the target position. In some embodiments, this can be indicated using color on or around the target. For example, in one embodiment, a red border around the target is displayed when the instrument is far from the target, yellow is displayed when nearing the target, and green is displayed when the instrument is aligned with the target. Additionally or alternatively, in some embodiments, convergence on a solution that aims the instrument correctly on the target is depicted with a circle or other shape centered at the target position with a radius equal to the distance of the heading of the instrument from the target position. In other embodiments, such as depicted inFIG.9, a geometric shape such as a square or circle changes in size to indicate how well the desired path is achieved. In some embodiments, desirable paths for both the outer member924and the inner member922of an instrument920may be indicated on the screen with lines, dots, geometric shapes, or other imagery. For example, inFIG.9, the following are depicted: a rectangle940around the target915, a rectangle942adjacent the location of the articulation section of the inner member922, and a rectangle944adjacent the location of the articulation section of the outer member924. In one embodiment, the rectangle940around the target915changes in color or size to indicate the extent to which the instrument is following a suitable path to the target. In one embodiment, a dot representing a heading direction of each articulation section appears within the rectangles942,944when the articulation sections are in a suitable position in the anatomical space. In some embodiments, such asFIG.10D, the dot indicates the projection of a distal tip of the instrument onto the plane of the ostium circle or other target plane (similar to a laser targeting system on a rifle placing a dot wherever the rifle is aimed). The dot may be provided to show the relationship between the tip of an articulation section and the target. In some embodiments, shown for example inFIG.10D, a “target radar” is provided as a visual indicator to facilitate understanding of the instrument position relative to the target. In the image, the crosshairs and circles show the space of articulation for the instrument (including articulation magnitude and articulation direction or “roll”). This is similar to polar coordinates. The “x” within the “radar” corresponds to the location of the instrument. Its position relative to the center corresponds to the heading direction and the circle corresponds to the outline of the vessel ostium or other target plane. In such embodiments, when the instrument is rolled, the “x” moves around the circles; when the instrument is articulated more, the x moves toward the outside of the circle, and when the instrument is relaxed, the x moves toward the center. Using this indicator, a user can determine which way to articulate and roll the instrument to align it with the target. A user may also use the targeting radar to discern which direction the instrument is aiming within the target ostium. In a sense, this works as a simplified endoscopic view of the instrument direction and target. Alternatively, a 3-D version of the indicator may be used that draws the indicator in 3-D space; the version may additionally draw the ostium with a projected heading of the instrument on the ostium surface defined by the ostium circle. A user may also use the targeting radar to discern which direction the instrument is aiming within the target ostium. In a sense, this works as a simplified endoscopic view of the instrument direction and target. Alternatively, a 3-D version of the indicator may be used that draws the indicator in 3-D space; the version may additionally draw the ostium with a projected heading of the instrument on the ostium surface defined by the ostium circle. As also shown, for example, inFIG.10D, some embodiments may display a shadow instrument representing the position the instrument is expected to assume if a user-entered movement command or the next proposed robot-determined command is implemented. Such an embodiment effectively provides a verification feature and requires another click or other user input before the system proceeds with implementing the commanded movement. In some embodiments, shown inFIG.13, dotted lines or other indicators are provided to show the ideal instrument path or the boundary of suitable paths for the instrument, and the user is able to see the difference between the actual instrument shape and the ideal instrument path to identify if deviation is occurring. In some embodiments, once the target is set, the system may allow the user to navigate with limited robotic assistance but will display one or more visual indicators indicating whether the instrument is following a suitable path. Visual cues such as colors, geometric shapes, diagrams, and/or a series of lights (for example, similar to airplane landing lights) may be displayed to show the relationship between the instrument and the target or the recommended path and the current path. In some embodiments, visual feedback is additionally provided to show when the various advanced driving modes have been enabled for various components of the instrument. For example, when the system is in an inner member driving mode, the target for the inner member may be the only visible target or may be specially highlighted, and similarly, when the system is in an outer member driving mode, the target for the outer member may be the only visible target or may be specially highlighted. In some embodiments, icons to the side of the virtual instrument or lighting on the user input device may indicate when various assisted driving buttons are enabled. In another embodiment, the system may display an appropriate articulation magnitude and/or direction to the user for the user to follow, in effect, providing textual or graphical turn by turn directions or step-by-step instructions, for example, telling the user which user inputs to select and when. While in such a “Driving Wizard,” which may include a sequence of messages (or dialogues or text boxes or symbols) guiding the user towards the target, undesirable motions may also be blocked to ensure that the user drives the instrument correctly or consistently with the guidance. In a similar embodiment, once the target is identified, the system may allow the user to drive, but the controller may create an alert and/or automatically stop movement of the medical instrument if a user command would move the instrument in such a way that reaching the target would become difficult or impossible. In still another embodiment or driving mode, referred to as robot-controlled navigation, the system fully controls navigation of the medical instrument including one or more of the articulation, roll, and translation. This is considered automated navigation and is made possible once a target position, heading, and lumen size are set. In such a mode, the system may control all movement of the medical instrument once the target is identified; in some embodiments, the system may control all movement while the user is selecting an associated user input command. For example, in some embodiments, the controller may calculate the amount of instrument articulation, rotation, and translation needed to reach the target in an optimal way. The translation, articulation, and rotation may be optimized so that the tip of the instrument is aligned with the target position as well as the target heading. The translation, articulation, and roll may also be optimized so that the shape of the medical instrument does not collide with the anatomy, if the system is able to make use of three dimensional preoperative imaging, other three-dimensional imaging, or two-dimensional imaging showing the outline or projection of the 3-D anatomy. In some embodiments, motion stops when the user stops actuating an automated driving button or other user input device. In other embodiments, it may be possible for the system to drive the instrument automatically even though the user has released the user input device. Some embodiments may automatically alternate between translating the instrument and modifying the articulation of the instrument. Other embodiments may automatically modify the articulation of the instrument as it is translated or allow the combination of user-commanded translation motions with robot-commanded control over articulation and roll. Other embodiments of robotic controlled navigation allow the user to specify the shape of the anatomy in the region so that the system can better calculate the translation, articulation, and/or roll of the instrument to align with the target. Some embodiments may make use of many of these sensing and navigation modalities to automatically compute all articulation and translation of the instrument to achieve a system that is able to navigate the instrument along a prescribed trajectory or a centerline of a body lumen. Methods for extracting the centerline from an image volume are described, for example, in U.S. Pat. No. 9,129,417, the disclosure of which is herein incorporated by reference in its entirety. This centerline generated from the 3-D volume may be used as the target for the automated robotic driving algorithm. In some embodiments, the navigation system may analyze the 3-D data set imported from a pre-op CT, MRI, or cone beam CT directly to compute the sequence of targets in three dimensions. In other embodiments, the navigation system processes one or a small number of 2-D images from an imaging system to improve the targeting algorithms. For example, each single image provides a two-dimensional constraint on the lumen shape when the outline in the 2-D image is projected into three dimensions; such information can be used to inform the target shape, heading, or location. If many images are acquired, such as during a rotation of the C-arm, the navigation system can reconstruct the 3-D shape using 2-D to 3-D reconstruction techniques (similar to how a CT is reconstructed). Robotic assisted driving techniques may be used to access any anatomical target. One non-limiting example includes the crossing of an occlusion in a blood vessel. In an occluded blood vessel, there is no blood flowing so it is not possible to image the anatomy using an angiogram under fluoroscopy. However, recent developments in CT scanning can identify the thrombus or calcium making up the occlusion and can identify the centerline of the occluded vessel. This three-dimensional information of the centerline of vessels can then be used to generate a sequence of targets that comprise the catheter trajectory. The robotic assisted driving algorithm of some embodiments is configured to use these targets as a path and navigate from the beginning of the occlusion to the location where the vessel reconstitutes by following this centerline while crossing the occlusion. In some embodiments, the robotic control system may automatically extract the centerline data and follow it. In alternative embodiments, robot-controlled navigation can occur intermittently; for example, a user may begin driving the medical instrument and select the robot-controlled navigation on occasion in order to have the system make path corrections. At times, it is important to prevent the computed articulation or roll from articulating the medical instrument in a constrained situation, because it is important to prevent the instrument from pressing into the anatomy. Similarly, it is important to prevent a computed insertion from inserting the instrument into the anatomy. Some embodiments may include a subsystem that monitors the instrument motion in relation to instrument commands such as articulation and insertion. By modeling the commands and comparing them to the measured catheter shape, the system is able to determine whether it is likely that the medical instrument is contacting the anatomy. Some embodiments may also calculate, based on this difference between the commanded shape and the measured shape, an estimate of the force applied on the instrument by the anatomy (and likewise, the force of the instrument on the anatomy). If the computed force gets large, the system may prevent further motion or cause a relaxation of the instrument to reduce this force on the anatomy. Some embodiments may also provide a message to the user or prevent assisted navigation when the computed force becomes too large. Some embodiments may also compute this force even when the user is not using assisted navigation to prevent the user from inadvertently causing too much force on the anatomy during navigation. During navigation, the instrument commands are represented as an articulation magnitude, roll angle, and insertion length, and therefore the controller directly modifies the commands to facilitate the driving. The commands are modified to serve different tasks at different stages of driving. For example, in the beginning, the focus may be on cannulating a vessel, and the controller may focus on aiming at the target. As the procedure progresses, and the flexible instrument approaches the target, the controller may focus on bringing the instruments through the target, requiring a different strategy than aiming the instruments at the vessel. In both cases, the modifying commands must be defined in the same coordinate system as the commands issued by the physician. In various embodiments, the desired articulation and roll commands are defined in a frame of reference of the instrument sensors, often located at the base of the articulation section. In some embodiments, the frame of reference may be computed from the virtual instrument shape, which can be defined by a combination of one or more of the sensor data, the articulation command to the medical instrument, a simulation of the instrument dynamics, and a model of instrument behavior. Once the target is also identified in this frame of reference, the desired articulation and roll commands are generated to aim the instrument at the target. In some embodiments, a search algorithm is employed to find the optimal articulation and roll angle. In another embodiment, an optimization procedure can determine the best articulation, roll, and insertion. In another embodiment, the frame of reference of the instrument is no longer attached to the base of the instrument's articulation section, but is instead calculated based on the shape of the virtual instrument constructed from sensor measurements as well as commands to the instrument. The coordinate frame at the distal tip of the instrument is directly measured by the sensors, but the frame at the base of the articulation section is calculated from inverting the kinematics that describes the relationship between the articulation magnitude and the position of the distal tip. The resulting frame of reference is no longer placed at the base of the articulation section, but instead takes into consideration the shape of the instrument and the command that caused the instrument to take the shape. This may lead to faster convergence and improved targeting performance. In open loop control, calculations from the sensors are used with the target location data to compute a single direction to move the medical instrument. This approach has the advantage of control stability, but variations in instrument behavior may prevent the instrument from aiming directly at the target. In closed loop control, the system takes into consideration the sensed position of the instrument as it moves and adjusts the instrument command accordingly to make the aim of the instrument converge on the target. In one embodiment, a polar coordinate system such as the targeting radar indicator displayed inFIG.10Dis used to compute the difference between the center of the target and the current heading of the instrument. A change in articulation and roll angles can be identified and added to the current instrument command to better align the instrument with a target. In various embodiments, large commanded changes may need to be divided into a series of smaller steps to prevent overshooting the target. On the other hand, a miniscule change or step may be magnified to overcome non-linear characteristics of the instrument, such as friction, dead-zone, or slack in a pullwire, to ensure that the instrument exhibits noticeable motion during assisted driving. In addition to the setting time, a distance threshold may be implemented to stop further modifications to the command if the aim of the instrument is close enough to the target. The threshold prevents the instrument from unnecessarily overshooting the target and keeps the aim of the instrument from drifting away from the target once the target has been reached. In various embodiments, once a desired instrument articulation and roll are computed, the controller34breaks them into driving commands. In one embodiment, the instrument may be commanded to first relax if it needs to change roll direction more than 90 degrees instead of rotating the instrument. Once the instrument is fully relaxed, the roll angle can be set directly so that the instrument bends in the desired roll direction. This is similar to the adaptive catheter control strategies outlined in US Publ. No. 2016/0213884, now abandoned, the disclosure of which is herein incorporated by reference in its entirety. Robotic assisted driving may involve the task of advancing an instrument formed of a plurality of members towards or through a target. In some embodiments, one or more of the above systems and methods are used to robotically assist driving an inner member through the target. Once the leading, inner member is passed through the target, an enhanced robotic assisted driving algorithm and method may be implemented so that any coaxial outer members “follow” over the leading member. During navigation of the outer member, the shape of the inner member provides an ideal path for the outer member to follow. In some embodiments, “following” involves inserting the outer member towards the target while articulating the outer member in the direction of the target, thereby following a path similar to the ideal path. In other embodiments, additional steps are needed to ensure accurate following and to avoid prolapse or loss of wire or instrument position. There is a risk of prolapse any time a flexible instrument changes directions during insertion. Prolapse is a situation where insertion of the instrument causes a proximal portion of the instrument to continue moving in the direction of a previous insertion command and bulge away from a target instead of changing directions and advancing with the distal tip toward the target. InFIG.13, for example, a prolapse in the leader catheter1324is shown as a bulge above the level of the target ostium1302; in this situation, further insertion of the leader catheter1324would cause it to buckle further up into the aorta1304and ultimately pull the tip of the leader catheter1324and the guidewire1322out of the ostium. This situation is important to avoid because it can add significant delays to a procedure. The prolapse of the leader catheter1324or other inner member is often controlled by the orientation of the sheath catheter1326or other outer member. For example, inFIG.13, the likely cause of the prolapse in the leader catheter1324is the fact that the tip of the sheath1326is aimed significantly away from the ostium1302of the vessel and the change in direction was too great. If the sheath catheter1326were instead articulated to point more towards the ostium1302, the leader catheter1324would be directed more towards the target and would have more support as it is inserted. The additional support enables the insertion motion to move the leader catheter1324through the ostium1302and into the vessel instead of further up into the aorta1304. Additionally or alternatively, in some embodiments, avoiding prolapse involves retracting an inner member1324before articulating the outer member1326towards the bend or target. Because the controller34is aware of the shape of the instrument1320, some embodiments make use of this information to automatically avoid these prolapse situations or, if they are detected, to move the instrument1320in such a way that the prolapse is removed. In some embodiments, the controller34is programmed and the system configured to detect prolapse within the instrument and notify the user and/or stop motion. In some embodiments, avoiding prolapse involves relaxing the outer member1326articulation then articulating the outer member1326in the path direction of the guidewire1322or inner member1324. The path of the guidewire1322or inner member1324may be defined by the virtual instrument shape generated from the sensor data. The shape of the virtual instrument constructed from the sensor measurements is naturally smooth and closely mimics that of the real instrument. The virtual instrument provides sufficient information to generate proper commands for the real instruments. In some embodiments, instrument commands may be further refined based on the position and heading of the target as well as the shape of an instrument portion. In one embodiment, the controller34determines an appropriate articulation angle θcmdfor the outer member based, in part, on the shape of the inner member. As shown inFIG.14, to determine the appropriate articulation angle θcmd, the average inner member shape in a local area is calculated, and the controller solves for the articulation angle θcmdand that will make the outer member curvature match the average inner member shape the best. The controller may then command the instrument driver to achieve this articulation angle. For example, inFIG.14, a first heading value H1is sampled at a first location L1proximal to the tip of the outer member1404, and a second heading value H2is sampled at a second location L2distal to the tip of the outer member1404. The heading values are averaged to find the average shape of the inner member1402in the sampled region, denoted as θtrack. The length of the articulation section is denoted as d, and the length of the sampled portion (i.e., the length of the inner member1402between L1and L2) is denoted as d′. The appropriate articulation angle θcmdis then calculated using the following proportion equation: θcmd=θtrack(d/d′). In another embodiment, the curvature of the articulation section is determined from averaging the curvature across portions of the virtual instrument. In various embodiments, the algorithms used to calculate the articulation and roll of an instrument in assisted driving may need to take into consideration the pulsatile flow in the arteries as well as heart and breath motions. In some embodiments, biological motions of the patient may be predicted and used to improve the performance of assisted driving. For example, in the images, the target may appear to move in sync with the patient's motion. Motion of the target may be sensed based on the instrument motion, live imaging such as fluoroscopy, or user input. The systems and methods of some embodiments detect and compensate for this cyclic motion, stabilizing the algorithm to converge faster. Some embodiments use an adjusted or moving target during computations of the translation, articulation, and/or roll. One embodiment of robotic-assisted driving is provided inFIGS.15A-15E. In the provided illustrations, a virtual instrument1510is superimposed on the anatomical image1500. The virtual instrument1510includes a virtual guidewire1512, a virtual inner member1514, and a virtual outer member1516. In the provided example, the anatomy is representative of a patient's left renal artery branching from the aorta when viewed from an anterior/posterior projection, but similar branches are present in other lumens within the body. The dashed line1520is provided in the visual display of some embodiments to show the desired target path of the instrument1510from its current position to the user-set target1530. The dashed line1520(i.e., the desired path) may be positioned at the centerline of the body lumen when within a relatively large or straight lumen1502and may follow a lowest energy curve or optimal path based on the bending radius of the instrument as it navigates lumen branches1504. The end target1530for the instrument1510is in the side branch vessel1504. If this target endpoint were established as the first target for both the inner member1514and the outer member1516, then both members would bend towards the target as shown by the solid arrows ofFIG.15Aand deviate from the desired path. This would lead to both members colliding with the wall of the aorta1502. To prevent such an outcome, in various embodiments of robotic-assisted driving, the controller34is configured to determine and set one or more intermediate targets that the instrument components aim for along their path to the final user-designated target. For example, as shown inFIG.15B, in the depicted progression, the controller34has set a first target point1532at the ostium of the vessel. This is a suitable target point for the inner member1514in this configuration but not for the outer member1516. If the outer member1516were bent towards the target1532, then the inner member1514would need to make a very sharp bend as shown by the dashed line1522. Instead, it is preferred to set up an additional target point for the outer member, as shown by the visual indicator1534inFIG.15C. The target point1532for the inner member remains unchanged. Both the target points1534and1532are located approximately on the preferred trajectory or desired target path1520of the instrument. Once the target1534for the outer member is set, any movements of the outer member1516determined and commanded by the robot will be selected to direct the tip of the outer member1516towards the target as shown by the long arrow. Similarly, once the target1532is set for the inner member1514, any movements of the inner member1514determined and commanded by the robot will be selected to direct the inner member1514towards that target1532as shown by the short arrow. It is worth noting thatFIGS.15A-Edepict a single 2D image of the target and the instrument for simplicity. In various embodiments of the surgical environment, a second image of a different projection is also provided. The concepts described here for a single 2D image also hold true in 3D. The inner and outer members are both assigned a target in 3D space and are commanded to move towards those targets. As shown inFIG.15C, once the inner member1514and the outer member1516are aligned towards their targets and are close to the targets, the guidewire1512may be advanced through the inner member target1532. Once the guidewire1512is advanced through the target1532, further forward motion of the instrument may be programmed to follow the guidewire. The inner member1514may need to be relaxed or straightened as it advances beyond the apex of the bend to follow the guidewire1512; however, in some embodiments, it may not be necessary to set new targets for the instrument. In other embodiments, if further navigation into complex anatomy is required, the inner member target may be relocated, as shown inFIG.15D. In the illustration, the new target1536is set at the distal end of the branch lumen while the outer member target1534remains outside the ostium of the vessel so that the outer member1516provides adequate support on the desired dashed line. The outer member1516eventually is commanded by the controller34to “follow” the inner member1514, as shown inFIG.15E. As with the inner member1514, once the outer member1516advances beyond its target1534, the controller34may direct the outer member1516to follow the inner member1514or the guidewire1512. Alternatively, a new target point may be set for the outer member1516. In other embodiments, such as ablation procedures, the control algorithm of the controller34may be set up such that the instrument1510never advances passed the target. In ablation procedures, the goal is to get a catheter tip to a target and it might be desirable as a safety measure to never allow the catheter or other instrument to extend beyond the target point. This would reduce the risk of inadvertent vessel perforation. As discussed above, the degree of operator involvement in the setting of the targets and the driving towards or through the targets may vary. In one preferred embodiment, the operator identifies the end target, the robotic system identifies a centerline or lowest energy path, the operator control insertion of the guidewire and insertion and bend of the inner member, and the controller34automatically determines and controls the roll of the inner member and all movement (i.e., insertion, bend, and roll) of the outer member. While multiple embodiments and variations of the many aspects of the invention have been disclosed and described herein, such disclosure is provided for purposes of illustration only. Many combinations and permutations of the disclosed systems and methods are useful in minimally invasive medical intervention and diagnosis, and the systems and methods are configured to be flexible. The foregoing illustrated and described embodiments are susceptible to various modifications and alternative forms, and it should be understood that the invention generally, as well as the specific embodiments described herein, are not limited to the particular forms or methods disclosed, but also cover all modifications, equivalents, and alternatives falling within the scope of the appended claims.

11857282

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT According to the present invention, the operating procedures and parameter conditions of a joint are within the professional literacy and routine techniques of those having ordinary skill in the art. According to the present invention, the operating procedures and parameter conditions of a motor are within the professional literacy and routine techniques of those having ordinary skill in the art; and the motor used in the present invention can be any of the conventionally used motor types in the technical art of the present invention. According to the embodiment of the present invention, the materials of the robotic arm, the sleeve of the robotic arm, or an outer protective film of the robotic arm is, but not limited to, a bio-compatible rubber, a silicone, a latex, a plastic (e.g. PVC, PU, PP, PE, PTFE, etc.), a stainless steel, a plastic steel, a metal (e.g. Titanium alloy or Titanium six aluminum four vanadium (Ti6Al4V)), a composite material, a wood, or other materials. According to the embodiments of the present invention, the operating procedures and parameter conditions related to the wireless connection are within the professional literacy and routine techniques of those having ordinary skill in the art; and the wireless connection used in the present invention can be any of the conventionally used types in the art of the present invention, which can be but not limited to infrared, Bluetooth, ZigBee, ANT, Wi-Fi, etc. Please refer toFIG.1, which is the schematic view of the multi-segment rotation robotic arm1of the present invention. The multi-segment rotation robotic arm1comprises a plurality of concatenated robotic arm segments11and a terminal robotic arm segment12located at a terminal of the multi-segment rotation robotic arm1. Wherein, the concatenated robotic arm segment11has a front end and a rear end, and the two of the serially concatenated robotic arm segments11or the terminal robotic arm segment12can rotate along the adjacent oblique section; and the front end of the terminal robotic arm segment12can be further disposed with a clamp or a lighting source device. Please refer toFIGS.2A and2B, which show the cross-sectional view of the different sleeves of the multi-segment rotation robotic arm of the present invention, respectively.FIG.2Ais the sleeve of one embodiment of the present invention, and the sleeve111is applied to the concatenated robotic arm segment11. The sleeve111is an elliptical cylinder, as shown in the section A-A′, and the two ends of the sleeve111are a front end oblique section1111near the front end and a rear end oblique section1112near the rear end respectively. The internal structure of the sleeve111has a hollow structure penetrating the front end oblique section1111and the rear end oblique section1112; wherein, the front end oblique section1111and the rear end oblique section1112are both a circle (as shown in section B-B′), and the front end oblique section1111and the rear end oblique section1112respectively form an acute angle of 20-85 degrees with the longitudinal axis of the elliptical cylinder of the sleeve111, and the acute angle is preferably 40-80 degrees. FIG.2Bis the sleeve of another embodiment of the present invention, and the sleeve111′ is applied to the terminal robotic arm segment12. The sleeve111′ is also an elliptical cylinder, as shown in the section C-C′, and the two ends of the sleeve111′ are a front end oblique section1111near the front end and a vertical oblique section1113near the rear end respectively; wherein, the front end oblique section1111is a circle (as shown in section D-D′), which forms an acute angle of 20-85 degrees with the longitudinal axis of the elliptical cylinder of the sleeve111′, and the acute angle is preferably 40-80 degrees. The vertical oblique section1113at the rear end (as shown in section C-C′) forms a vertical angle with the longitudinal axis, so that the vertical oblique section1113forms a platform for further disposition and/or connection of other instruments or devices on the platform. In one embodiment of the multi-segment rotation robotic arm of the present invention, referring toFIGS.3A and3B, the hollow structure penetrates both ends of the sleeve111, and a supporting device110, a pivoting structure112, and a driving device113for driving the pivoting structure are disposed in the hollow structure. The supporting device110is fixed in the sleeve111to fix and support the pivoting structure112, the driving device113, the signal receiving module114, and the signal processing module115in the concatenated robotic arm segment11. The supporting device110comprises a supporting frame1101and a supporting base1102, wherein the supporting frame1101penetrates the front and rear ends of the concatenated robotic arm segment11, and the supporting base1102is fixed at the rear end oblique section1112of the sleeve111. The pivoting structure112is located between the front end oblique section1111and the rear end oblique section1112adjacent to the two serially concatenated robotic arm segments11, and the driving device113is disposed inside the hollow structure of the sleeve111of the concatenated robotic arm segment11to drive the pivoting structure112, so that the two serially concatenated robotic arm segments11move relatively to each other along the adjacent oblique sections; wherein a circular flange1114is formed on the rear end oblique section1112, and a circular groove1115is formed on the front end oblique section1111. When the front end oblique section1111and the rear end oblique section1112are adjacent to each other, the circular flange1114and the circular groove1115cooperate with each other to keep the adjacent oblique sections rotating relatively to each other, and to prevent the deviation between the two oblique sections. The driving device113in the concatenated robotic arm segment11of the present invention further comprises a signal receiving module114and a signal processing module115; wherein the signal receiving module114is wirelessly connected to a remote control device, and the signal processing module115is electrically connected to the signal receiving module114and the motor1131; wherein the signal receiving module114wirelessly receives a motor control signal from the remote control device, and then sends the motor control signal1141to the signal processing module115; and after receiving the motor control signal1141, the signal processing module115calculates a rotation angle; and then, the signal processing module115controls the motor1131to perform a corresponding rotation according to the rotation angle, and drives the two serially concatenated robotic arm segments11to perform relative rotation at the rotation angle along the adjacent oblique sections. Please continue to refer toFIG.4, the pivoting structure112comprises: a front end joint1121, which is near the front end oblique section1111; a rear end joint1122, which is near the rear end oblique section1112of the next concatenated robotic arm segment11; and a T-shaped structure1123, which is extending from the rear end joint1122; wherein the front end joint1121and the rear end joint1122are pivotally coupled by a universal joint, and a pivoting angle maintained by the front end joint1121and the rear end joint1122is the angle maintained along the two oblique sections of the two serially concatenated robotic arm segments11. The motor1131is installed in the hollow structure near the front end of the concatenated robotic arm segment11, and a rotating shaft of the motor1131is coupled to the front end joint1121to rotate the front end joint1121to drive the rotation of the rear end joint1122. In addition, the T-shaped structure1123extended from the rear end joint1122is connected to the supporting base1102which is at the rear end of the concatenated robotic arm segment11, so that the concatenated robotic arm segment11concatenated in series follows the rotation of the pivoting structure112to rotate. In another embodiment of the present invention, the terminal robotic arm segment12is the first robotic arm segment of the multi-segment rotation robotic arm1, and the front end oblique section1111of the terminal robotic arm segment12and the rear end oblique section1112of the concatenated robotic arm segment11are adjacent to each other in the aforementioned manner, and the hollow structure of the sleeve111′ and the hollow structure of the sleeve111communicate with each other. In another embodiment of the present invention, the terminal robotic arm segment12is the last robotic arm segment of the multi-segment rotation robotic arm1, and the front end oblique section1111of the terminal robotic arm segment12and the front end oblique section1111of the concatenated robotic arm segment11are adjacent to each other in the aforementioned manner, and the hollow structure of the sleeve111′ and the hollow structure of the sleeve111communicate with each other; wherein, the front end oblique section1113of the terminal robotic arm segment12can be, but not limited to, a structure which has installed a specific instrument device, such as a clamp, so that the terminal robotic arm segment12forms a specific unit body, which can be replace according to the use requirements. In other embodiments of the present invention, the entire combination of pivoting structure112and the driving device113may be a piezoelectric motor, more specifically, may be an ultrasonic piezoelectric motor. For example, the driving device113is a driving part of the piezoelectric motor and is arranged in the concatenated robotic arm segment11, and the pivoting structure112is a sliding rail part of the piezoelectric motor and is arranged in the next concatenated robotic arm segment11. In this way, when the driving part of the concatenated robotic arm segment11is operating, the slide rail part of the next concatenated robotic arm segment11can be driven to rotate. Please refer toFIG.5, the multi-segment rotation robotic arm1of the present invention can arbitrarily concatenate a plurality of the concatenated robotic arm segments11of the present invention in series according to the use requirements, and the concatenating way of the concatenated robotic arm segments11enables themselves to rotate 360 degrees along the oblique section of each other when they rotate relatively to each other, and the electric supply will not be affected by the rotation at all, so as to reduce the volume increase by rotated joints, so the multi-segment rotation robotic arm1of the present invention can be more effectively adapt to the complex and tortuous space in the body cavity to reduce the possibility of expanding the opening of the minimally invasive surgery and causing damage to organs or tissues in the body cavity, and because each concatenated robotic arm segment11of the multi-segment rotation robotic arm1of the present invention can be independently controlled, the multi-segment rotation robotic arm1of the present invention to adapt to the environment in terms of mobility and accuracy. Referring toFIG.6, in another embodiment of the present invention, the driving device113comprises: an electric motor1131, and an electrical conductive element1132electrically connected to the motor1131. The electrical conductive element1132is a conductive ring combination11321and a conductive wire combination11322, wherein the conductive wire combination11322electrically connects the conductive ring combination11321with the driving device113, the signal receiving module114, and the signal processing module115respectively; and the conductive ring combination11321is arranged on the circular flange1114and the circular groove1115of the concatenated robotic arm segment11respectively; thus, when the concatenated robotic arm segment11is concatenated in series, the two of the concatenated robotic arm segments11are electrically connected by the conductive ring combination11321to conduct electricity; wherein the conductive ring combination11321is a circular metal ring, so that the rotation of the robotic arm segments concatenated in series would not affect the conduction of electricity. In another embodiment of the present invention, not shown in the FIGs, the electrical conductive element1132is a battery, and the battery is disposed in the driving device113and electrically connected to the electric motor1131to independently provide electricity for the driving device113of a single concatenated robotic arm segment11, so that the rotation of the robotic arm segments concatenated in series would not affect the conduction of electricity. In an embodiment of the present invention, the driving device113further comprises a receiving module114, an electric motor1131/an instrument device116, and a signal processing module115, wherein the signal receiving module114receives a control signal and sends the control signal to the signal processing module115, and the signal processing module115receives the control signal to calculate a rotation angle/an operation instruction; please refer toFIG.7for the transmission and reception methods of electricity and signals, including, but not limited to, any of the4methods mentioned below:(1) The conductive ring combination11321transmits electricity to the signal receiving module114, the signal processing module115, and the electric motor1131/the instrument device116, wherein the signal receiving module114wirelessly receives the control signal and sends it to the signal processing module115to control the electric motor1131/the instrument device116without using batteries;(2) The conductive ring combination11321transmits electricity and carrier control signals, and the electricity is transmitted to the signal receiving module114, the signal processing module115, and the electric motor1131/the instrument device116, wherein the signal receiving module114receives and carries the control signal by wire, and transmits it to the signal processing module115to control the electric motor1131/the instrument device116without using batteries. In addition, the number of the rings of the conductive ring combination11321and the conductive wire combination11322is not limited to two. In other embodiments of the present invention, the number of the rings may be more than two, such as four rings, six rings, etc., and each ring can be electrically connected to the signal receiving module114, the signal processing module115and the electric motor1131/the instrument device116, so that different signals can be transmitted to the electric motor1131/the instrument device116through different rings, and then the electric motor1131rotates a predetermined angle or the instrument device116performs an action;(3) The conductive ring combination11321transmits the control signal, and further comprises the battery to provide electricity to the signal receiving module114, the signal processing module115, and the electric motor1131/the instrument device116; wherein the signal receiving module114receives the control signal by wire and transmits it to the signal processing module115to control the electric motor1131/the instrument device116;(4) The battery provides electricity to the signal receiving module114, the signal processing module115, and the electric motor1131/the instrument device116; wherein, the signal receiving module114wirelessly receives the control signal and transmits it to the signal processing module115to control the electric motor1131/the instrument device116. The robotic arm of the present invention can be further equipped with an instrument device for microsurgery, wherein the accessory instrument for surgery is a commonly used instrument for those with ordinary skill in the art of the present invention, which can be, but not limited to, a scissors, a clamp, a hemostat, a hook, an electrosurgical unit, or a harmonic scalpel, etc. Referring toFIG.8, in an embodiment of the present invention, the terminal robotic arm segment12of the multi-segment rotation robotic arm1further comprises an instrument device116; wherein the signal receiving module114is wirelessly connected to a remote control device, and the signal processing module115is electrically connected to the signal receiving module114and the instrument device116; wherein the signal receiving module114wirelessly receives an instrument device control signal from the remote control device, and then transmits the instrument device control signal to the signal processing module115; and after receiving the instrument device control signal, the signal processing module115calculates an operation instruction, and then the signal processing module115controls the operation of the instrument device116according to the operation instruction. In one embodiment of the present invention, the robotic arm may further comprise a magnet, or the concatenated robotic arm segment11itself is made of magnetic material, so that when performing surgical operations with the robotic arm of the present invention, the positioning of the robotic arm extending into the affected area can be controlled by magnetic force outside or inside of the body, or the weight-bearing capacity of the robotic arm can be increased Referring toFIG.9, the robotic arm of the present invention may further comprise an image transmission device, a lighting source device, or any combination thereof, which is directly arranged at the front end of the end robotic arm segment of the multi-segment rotation robotic arm1of the present invention, i.e. the rear end oblique section1113of the terminal robotic arm segment12, or is arranged in the hollow structure penetrating the concatenated robotic arm segment11and the terminal robotic arm segment12and extends to the front end of the last robotic arm segment. As shown inFIG.9, the concatenated robotic arm segment11and the terminal robotic arm segment12of the present invention can adapt to the complex and tortuous space in the body cavity through multiple different rotation angles to reduce the possibility of expanding the wound and reduce the risk of causing organ and tissue damage in the body cavity. In addition to being directly used, the multi-segment rotation robotic arm1of the present invention can also be used after being coated with a protective film on the outer surface of the multi-segment rotation robotic arm1, so as to reduce the cleaning burden and failure of the multi-segment rotation robotic arm1, and can improve safety. The robotic arm of the present invention can be applied to throat endoscopes, gastrointestinal endoscopes, abdominal endoscopes, thoracic endoscopes, pelvic gun endoscopes and other operations based on common skill in the art of the present invention. It is worth mentioning that the present invention uses a multi-segment rotation robotic arm which belongs to a flexible tube to replace the conventional optical fiber and can be operated by automatic mechanization. In this way, the robotic arm of the present invention can easily apply force and transmit force to move and rotate in places such as the throat and intestines, and adapt to the complex and tortuous space in the body cavity through multiple rotation angles; in addition, the robotic arm of the present invention1can also be covered with a layer of intestinal cleansing devices commonly used in the art of the present invention to improve the accuracy and efficiency of cleaning the intestines. The application of the multi-segment rotation robotic arm1of the present invention in laparoscopic endoscopic surgery will be described in detail below; however, those with ordinary skill in the art of the present invention should be able to understand that such detailed descriptions and specific examples for implementing the present invention are only used to illustrate the present invention, and are not intended to limit the scope of the claims of the present invention. EXAMPLE The application of the multi-segment rotation robotic arm of the present invention in abdominal endoscopic surgery One embodiment of the present invention is the application of the multi-segment rotation robotic arm1in peritoneal endoscopic surgery. After using the conventional art in the art of the present invention to have wounds of abdominal endoscopic surgery and infuse carbon dioxide into the abdominal cavity to open up the space, (1) the multi-segment rotation robotic arm1of the present invention in which the instrument device116is a clamp, (2) the multi-segment rotation robotic arm1of the present invention in which the instrument device116is another clamp, and (3) the multi-segment rotation robotic arm1of the present invention comprising an image transmission device and a lighting source device are respectively inserted into the body through the open wound. Because the multi-segment rotation robotic arm1of the present invention is small in size and has multiple joints which can rotate 360 degrees without affecting the volume of the multi-segment rotation robotic arm1, so that when the aforementioned (1) to (3) are placed into the abdominal cavity of the patient, the multi-segment rotation robotic arm1can adapt to the complex and tortuous space in the body cavity to reduce the possibility of expanding the opening of the minimally invasive surgery and causing damage to organs or tissues in the body cavity. Then, an erecting platform which can be folded into a small volume can also be placed in the abdominal cavity of the patient through the wound, and because the multi-segment rotation robotic arm1of the present invention can further comprise a magnet or have polarity itself, a magnet could be used to properly adjust the position of the above-mentioned (1) to (3) and the erecting platform in the abdominal cavity of the patient on the outside of the body, and after the relative distance of the objects is shortened, the erecting platform is spread out and the aforementioned (1) to (3) are combined on the erecting platform to form a complete minimally invasive surgery operation assembly, and, the electric motor control signal or the instrument device control signal is transmitted to the robot arm1of the present invention through the remote control device to control the multi-segment rotation robotic arm1of the present invention for minimally invasive surgery. In summary, in the multi-segment rotation robotic arm1of the present invention, the both end oblique sections of the sleeve111of the concatenated robotic arm segment11and the front end oblique section1111of the sleeve111′ of the terminal robotic arm segment12are a circle with the same diameter, so that after the concatenated robotic arm segment11and/or the terminal robotic arm segment12of the present invention is concatenated in series, the concatenated robotic arm segments11and/or the terminal robotic arm segments12concatenated in series can completely perform relative rotations of up to 360 degrees along the adjacent oblique sections of the two concatenated of the robotic arm segments without extra volume. In addition, since the hollow structure penetrating both ends of the concatenated robotic arm segment11and/or the terminal robotic arm segment12takes the rotation center of the pivoting structure as the center point of itself, objects placed in the hollow structure would not be affected when the concatenated robotic arm segment11and/or the terminal robotic arm segment12concatenated in series perform relative rotational movement. Furthermore, in the multi-segment rotation robotic arm1of the present invention, each concatenated robotic arm segment11and/or the terminal robotic arm segment12of the robotic arm is concatenated in series with the conductive ring combination11321, so that it is only necessary to connect an external electric supply to the terminal robotic arm segment12of the multi-segment rotation robotic arm1of the present invention for supplying electricity to the entire multi-segment rotation robotic arm1; and since the conductive ring combination11321is a circular metal ring, after the concatenated robotic arm segments11and/or the terminal robotic arm segments12are concatenated in series, the two robotic arm segments connected in series can freely rotate 360 degrees without affecting the conduction of electricity; or, each of the concatenated robotic arm segments11and/or the terminal robotic arm segments12concatenated in series has a battery to independently provide electricity for a single concatenated robotic arm segment11and/or the terminal robotic arm segment12, so that the rotation of the concatenated robotic arm segment11would not affect the conduction of electricity. In addition, in the multi-segment rotation robotic arm1of the present invention, each concatenated robotic arm segment11and/or the terminal robotic arm segment12comprises the independent signal receiving module114and the signal processing module115, and terminal the robotic arm segment12can further comprises the instrument device116, so that each concatenated robotic arm segment11and/or the terminal robotic arm segment12can be independently controlled to reduce each controlled unit and to improve the overall mobility and accuracy of the multi-segment rotation robotic arm1of the present invention. Therefore, the multi-segment rotation robotic arm1of the present invention can arbitrarily concatenate a plurality of the concatenated robotic arm segments11of the present invention in series according to the use requirements, and the concatenating way of the concatenated robotic arm segments11and/or the terminal robotic arm segments12enables them to rotate 360 degrees along the oblique section of each other when they rotate relatively to each other, and the electric supply will not be affected by the rotation at all, so as to overcome the limitation of the joint rotation angle of the conventional robotic arm in the art of the present invention, and to reduce the volume increase by rotated joints, so the multi-segment rotation robotic arm1of the present invention can be more effectively used in minimally invasive surgery with limited space configuration. Specifically, the multi-segment rotation robotic arm1of the present invention can effectively adapt to the complex and tortuous space in the body cavity to reduce the possibility of expanding the opening of the minimally invasive surgery and causing damage to organs or tissues in the body cavity. Moreover, because each concatenated robotic arm segment11and/or the terminal robotic arm segment12of the multi-segment rotation robotic arm of the present invention can be independently controlled, this method of reducing the control unit enables the multi-segment rotation robotic arm1of the present invention to adapt to the environment in terms of mobility and accuracy.

11857283

The drawings are not intended to be limiting in any way, and it is contemplated that various embodiments of the technology may be carried out in a variety of other ways, including those not necessarily depicted in the drawings. The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present technology, and together with the description serve to explain the principles of the technology; it being understood, however, that this technology is not limited to the precise arrangements shown. DETAILED DESCRIPTION The following description of certain examples of the technology should not be used to limit its scope. Other examples, features, aspects, embodiments, and advantages of the technology will become apparent to those skilled in the art from the following description, which is by way of illustration, one of the best modes contemplated for carrying out the technology. As will be realized, the technology described herein is capable of other different and obvious aspects, all without departing from the technology. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not restrictive. It is further understood that any one or more of the teachings, expressions, embodiments, examples, etc. described herein may be combined with any one or more of the other teachings, expressions, embodiments, examples, etc. that are described herein. The following-described teachings, expressions, embodiments, examples, etc. should therefore not be viewed in isolation relative to each other. Various suitable ways in which the teachings herein may be combined will be readily apparent to those of ordinary skill in the art in view of the teachings herein. Such modifications and variations are intended to be included within the scope of the claims. For clarity of disclosure, the terms “proximal” and “distal” are defined herein relative to a human or robotic operator of the surgical instrument. The term “proximal” refers the position of an element closer to the human or robotic operator of the surgical instrument and further away from the surgical end effector of the surgical instrument. The term “distal” refers to the position of an element closer to the surgical end effector of the surgical instrument and further away from the human or robotic operator of the surgical instrument. It will be further appreciated that, for convenience and clarity, spatial terms such as “front,” “side,” “top,” “bottom,” “rear,” “horizontally,” “vertically,” “clockwise,” “counterclockwise,” “longitudinal,” “oblique,” and “transverse” also are used herein for reference to relative positions and directions. Such terms are used below with reference to views as illustrated for clarity and are not intended to limit the invention described herein. I. Exemplary Surgical Instrument FIG.1shows an exemplary surgical instrument (10). Surgical instrument (10) of the present example comprises a body assembly, such as a base assembly (12), a shaft assembly (14), and an end effector (16). At least part of surgical instrument (10) may be constructed and operable in accordance with at least some of the teachings of any of the various patents, patent application publications, and patent applications that are cited herein. As described therein and as will be described in greater detail below, surgical instrument (10) is operable to perform a function, such as clamping tissue, cutting tissue, coagulating tissue, holding or driving a needle, grasping a blood vessel, dissecting tissue, or cauterizing tissue. A. Exemplary Base Assembly Referring toFIGS.1-2, base assembly (12) includes a housing (18), a button (22), and a pair of latch clasps (24). Button (22) is operatively connected to an electrical base power controller (not shown) and configured to selectively power surgical instrument (10) for use. In addition, housing (18) of the present example includes a front housing cover (26) and a rear housing cover (28) removably secured together via latch clasps (24). More particularly, latch clasps (24) removably secure front housing cover (26) to rear housing cover (28) such that front housing cover (26) may be removed for accessing an interior space (not shown) within base assembly (12). Shaft assembly (14) distally extends from base assembly (12) to end effector (16) to thereby communicate mechanical and/or electrical forces therebetween for use as will be discussed below in greater detail. As shown in the present example, base assembly (12) is configured to operatively connect to a robotic drive (not shown) for driving various features of shaft assembly (14) and/or end effector (16). However, in another example, body assembly may alternatively include a handle assembly (not shown), which may include a pistol grip (not shown) in one example, configured to be directly gripped and manipulated by the surgeon for driving various features of shaft assembly (14) and/or end effector (16). The invention is thus not intended to be unnecessarily limited to use with base assembly (12) and the robotic drive (not shown). To this end, with respect toFIG.2, base assembly (12) includes a robotic driven interface (32) extending through a base plate (34) of rear housing cover (28) and configured to mechanically couple with the robotic drive (not shown). Robotic driven interface (32) of the present example includes a plurality of instrument actuators (36a,36b,36c,36d,36e,36f) having a plurality of input bodies (38a,38b,38c,38d,38e,38f), respectively. Each input body (38a,38b,38c,38d,38e,38f), which may also be referred to herein as a “puck,” is configured to removably connect with the robotic drive (not shown) and, in the present example, is generally cylindrical and rotatable about an axis. Input bodies (38a,38b,38c,38d,38e,38f) have a plurality of slots (40) configured to receive portions of the robotic drive (not shown) for gripping and rotatably driving input bodies (38a,38b,38c,38d,38e,38f) in order to direct operation of shaft assembly (14) and/or end effector (16) as will be discussed below in greater detail. Base assembly (12) also receives an electrical plug (42) operatively connected to an electrical power source (not shown) to provide electrical power to base assembly (12) for operation as desired, such as powering electrical base power controller (not shown) and directing electrical energy to various features of shaft assembly (14) or end effector (16) associated with cutting, sealing, or welding tissue. By way of example only, base assembly (12) may alternatively or additionally be configured in accordance with one or more teachings described in U.S. patent application Ser. No. 16/556,661, entitled “Ultrasonic Surgical Instrument with a Multi-Planar Articulating Shaft Assembly,” filed on Aug. 30, 2019, published as U.S. Pat. Pub. No. 2021/0059709 on Mar. 4, 2021, issued as U.S. Pat. No. 11,690,642 on Jul. 4, 2023; U.S. patent application Ser. No. 16/556,667, entitled “Ultrasonic Transducer Alignment of an Articulating Ultrasonic Surgical Instrument,” filed on Aug. 30, 2019, published as U.S. Pat. Pub. No. 2021/0059710 on Mar. 4, 2021, issued as U.S. Pat. No. 11,612,409; U.S. patent application Ser. No. 16/556,625, entitled “Ultrasonic Surgical Instrument with Axisymmetric Clamping,” filed on Aug. 30, 2019, published as U.S. Pat. Pub. No. 2021/0059707 on Mar. 4, 2021, issued as U.S. Pat. No. 11,471,181 on Oct. 18, 2022; U.S. patent application Ser. No. 16/556,635, entitled “Ultrasonic Blade and Clamp Arm Alignment Features,” filed on Aug. 30, 2019, U.S. Pat. Pub. No. 2021/0059708 on Mar. 4, 2021, issued as U.S. Pat. No. 11,457,945 on Oct. 4, 2022; and/or U.S. patent application Ser. No. 16/556,727, entitled “Rotatable Linear Actuation Mechanism,” filed on Aug. 30, 2019, published as U.S. Pat. Pub. No. 2021/0059711 on Mar. 4, 2021, issued as U.S. Pat. No. 11,712,261 on Aug. 1, 2023. The disclosure of each of these applications is incorporated by reference herein. Alternatively, base assembly (12) may be constructed and/or operable in any other suitable fashion. B. Exemplary End Effector As best seen inFIGS.3A-3B, end effector (16) of the present example includes an upper jaw (44) and a lower jaw (46) for clamping tissue. In the illustrated embodiment, upper jaw (44) is pivotally secured to a distally projecting tongue (50) of shaft assembly (14). Upper jaw (44) is operable to selectively pivot toward and away from lower jaw (46) to selectively clamp tissue between upper jaw (44) and lower jaw (46). A pair of arms (51) extend transversely from upper jaw (44) and are pivotally secured to another portion of shaft assembly (14) configured to longitudinally slide to pivot upper jaw (44) as indicated by an arrow (52) between a closed position shown inFIG.3Aand an open position shown inFIG.3B. While the present example of end effector (16) includes jaws (44,46) configured to grip tissue for manipulation thereof, it will be appreciated that any such end effector for use with tissue in a surgical procedure may be similarly incorporated into surgical instrument (10). Indeed, other suitable configurations for end effector will be apparent to one with ordinary skill in the art in view of the teachings herein, including, but not limited to, an endocutter, grasper, cutter, stapler, clip applier, access device, needle driver, scissors, retractor, spatula, hook, and energy delivery device using ultrasonic vibration, RF, laser, etc. The invention is thus not intended to be limited to end effector (16) shown in the present example. More particularly, and by way of example only, end effector (16) may alternatively or additionally be configured in accordance with one or more teachings described in U.S. Pat. Pub. No. 2019/0125464, entitled “Robotic Surgical Tool with Manual Release Lever,” published on May 2, 2019, issued as U.S. Pat. No. 10,624,709; U.S. Pat. Pub. No. 2012/0292367, entitled “Robotically-Controlled End Effector,” published on Nov. 11, 2012, now abandoned; U.S. Pat. No. 9,314,308, entitled “Robotic Ultrasonic Surgical Device With Articulating End Effector,” issued on Apr. 19, 2016; and U.S. Pat. No. 10,039,548, entitled “Clip Applier Adapted for Use with a Surgical Robot,” issued on Aug. 7, 2018. C. Exemplary Shaft Assembly and Articulation Section Having a First Exemplary Multi-Planar Articulation Joint As shown inFIGS.3A-3B, shaft assembly (14) includes a proximal shaft portion (60) extending along a longitudinal axis (61), a distal shaft portion (62) distally projecting relative to the proximal shaft portion (60) along a distal shaft axis (63), and an articulation section (70) extending between proximal and distal shaft portions (60,62). Shaft assembly (14) is configured to rotate about longitudinal axis (61) as indicated by an arrow (66). In one example, shaft assembly (14) rotates in the clockwise or counterclockwise directions completely around longitudinal axis (61) and may be selectively fixed in any rotational position about longitudinal axis (61) for positioning articulation section (70) and/or end effector (16) about longitudinal axis (61). Articulation section (70) is configured to selectively position end effector (16) at various lateral deflection angles relative to longitudinal axis (61) defined by proximal shaft portion (60). Referring toFIG.4, articulation section (70) comprises a first exemplary multi-planar articulation joint (65) configured to deflect end effector (16) (seeFIG.3A) through a plurality of planes. Multi-planar articulation joint (65) of the present example includes a proximal articulation joint interface (72a) extending distally from proximal shaft portion (60) (seeFIG.3A), a distal articulation joint interface (72b) extending proximally from distal shaft portion (62) (seeFIG.3A), and an articulation joint core (80) positioned between proximal and distal articulation joint interfaces (72a,72b). Articulation joint core (80) includes a first articulation joint member (82a) assembled with a second articulation joint member (82b) such that second articulation joint member (82b) is oriented about 90 degrees clockwise relative to first articulation joint member (82a) about longitudinal axis (61). Each of first and second articulation joint members (82a,82b) are thereby assembled to form articulation joint core (80), which is pivotable relative to longitudinal axis (61) of proximal shaft portion (60) (seeFIG.3A) to position end effector (16) (seeFIG.3A) in various positions about longitudinal axis (61). Referring toFIGS.4-5B, articulation joint core (80) is pivotable relative to proximal articulation joint interface (72a) about a first articulation axis (55) extending transverse to longitudinal axis (61). Articulation joint core (80) is thereby pivotable about first articulation axis (55) to deflect end effector (16) upwardly along a first plane relative to longitudinal axis (61), as shown by arrow (64) inFIG.5A, and/or downwardly along the first plane relative to longitudinal axis (61), as shown by arrow (66) inFIG.5B. Referring toFIG.4andFIGS.6A-6B, distal articulation joint interface (72b) is pivotable relative to articulation joint core (80) about a second articulation axis (57) extending transverse to both longitudinal axis (61) and first articulation axis (55). Distal articulation joint interface (72b) is thereby pivotable about second articulation axis (57) to deflect end effector (16) outwardly along a second plane relative to longitudinal axis (61), as shown by arrow (68) inFIG.6A, and/or inwardly along the second plane relative to longitudinal axis (69), as shown by arrow (59) inFIG.6B. Articulation joint core (80) and distal articulation joint interface (72b) may be articulated simultaneously or individually to deflect end effector (16) along the first and/or second planes as desired. Still other suitable articulation configurations for operating articulation section (70) will be apparent to one with ordinary skill in the art in view of the teachings herein. Articulation section (70) defines a centerline therethrough that similarly deflects to remain radially central within articulation section (70). In the present example, the centerline through articulation section (70) thus has a proximal portion that remains coaxial with longitudinal axis (61) and a distal portion that remains coaxial with distal shaft axis (65) regardless of the deflected or straight configurations available to multi-planar articulation joint (65). In order to selectively drive such articulation about the first and second articulation axes (55,57), a plurality of cables (96) extend from base assembly (12) (seeFIG.1) to multi-planar articulation joint (65). In the present example, proximal articulation joint interface (72a) is coupled with proximal shaft portion (60) and distal articulation joint interface (72b) is coupled with distal shaft portion (62). Four such cables (96) extend through openings (71a) of proximal articulation joint interface (72a), through corresponding channels (96a,98a,96b,98b) and openings (97a,97b) of articulation joint core (80), and through openings (71b) of distal articulation joint interface (72b). Cables (96) thereby connect to distal articulation joint interface (72b) such that pulling on cables (96) on one side of either first or second axes (55,57) will selectively articulate multi-planar articulation joint (65). It will be appreciated that such cables (96) may be pulled in various combinations to achieve any desired articulation about first and second axes (55,57). Still other suitable configurations for articulating multi-planar articulation joint (65) will be apparent to one with ordinary skill in the art in view of the teachings herein. Referring back toFIG.4, multi-planar articulation joint (65) further provides support and guidance for elongate members (90,92,94) extending through articulation section (70) that may couple components of base assembly (12) (seeFIG.1) and/or shaft assembly (14) (seeFIG.1) with end effector (16) (seeFIG.1) for operation of end effector (16) (seeFIG.1). For instance, one or more elongate members (90,92) may include cables acting in tension such that elongate member (90) may be used for pivoting upper jaw (44) into the closed position (seeFIG.3A) and elongate member (92) may be used for pivoting upper jaw (44) into the open position (seeFIG.3B). Accordingly, as shown inFIG.7, articulation joint core (80) may be assembled to support such elongate members (90,92) (seeFIG.4) in a lobe style configuration, as will be discussed in more detail below. Additionally or alternatively, one or more elongate members (94) may include a flexible control rod acting in compression and/or tension for pushing and/or pulling features within end effector (16) (seeFIG.3A). Accordingly, as shown inFIG.8, multi-planar articulation joint (65) may be assembled to support such elongate members (94) in a wedge style configuration, as will be discussed in more detail below. As shown inFIGS.4and9-11, multi-planar articulation joint (65) supports each of elongate members (90,94) along a continuous helical path to provide smooth control of elongate members (90,94) that inhibits catching, kinking, over-extension, and/or over-compression of such elongate members (90,94) during articulation of articulation section (70), particularly when simultaneously deflecting end effector (16) (seeFIGS.5A-6B) through multiple planes. In contrast, elongate member (92) extends along the centerline through proximal articulation joint interface (72a), articulation joint core (80), and distal articulation joint interface (72b) to be coaxial with axes (61,63) while straight and deflected, such that elongate members (90,94) are spirally positioned thereabout. To this end, multi-planar articulation joint (65) defines a plurality of lumens (91,93,95) for receiving and supporting elongate members (90,92,94). In the illustrated embodiment, elongate member (90) is positioned within lumen (91), elongate member (92) is positioned within lumen (93), and elongate member (94) is positioned within lumen (95). As with elongate members (90,92,94), each of lumens (91,95) extend along a continuous helical path, whereas lumen (93) extends along the centerline through articulation joint core (80) such that lumens (91,93,95) are spirally positioned thereabout. While three elongate members (90,92,94) are shown in the present example, any other suitable number and/or configurations for elongate members (90,92,94) may be used. Referring toFIG.9, a proximal portion of multi-planar articulation joint (65) is configured to laterally align lumens (91,93,95) to be offset from each other along and intersect with first articulation axis (55). Accordingly, as multi-planar articulation joint (65) pivots about first articulation axis (55), elongate members (90,92,94) are positioned along first articulation axis (55) such that elongate members (90,92,94) may articulate about first articulation axis (55) with multi-planar articulation joint (65). Referring toFIG.10, as elongate members (90,92,94) extend distally, lumens (91,93,95) support elongate members (90,92,94) within articulation section (70) to thereby laterally align elongate members (90,92,94) obliquely between first articulation axis (55) and second articulation axis (57). As elongate members (90,92,94) continue to extend distally, a distal portion of multi-planar articulation joint (65) is configured to laterally align lumens (91,93,95) to be offset from each other along second articulation axis (57), as shown inFIG.11. Thus, as distal articulation joint interface (72b) pivots about second articulation axis (57), elongate members (90,92,94) are positioned along and intersect with second articulation axis (57) such that elongate members (90,92,94) may articulate about second articulation axis (57) with distal articulation joint interface (72b) (seeFIG.12). Multi-planar articulation joint (65) thereby supports elongate members (90,92,94) in a collective helical configuration to align elongate members (90,92,94) along the select articulation axis (55,57) for supporting and guiding translation of elongate members (90,92,94) during articulation. In some versions, multi-planar articulation joint (65) is configured to inhibit elongate members (90,92,94) from translating within multi-planar articulation joint (65). Referring toFIGS.9and11, multi-planar articulation joint (65) is configured to maintain the spaced relationship between elongate members (90,94) (seeFIG.4) at each articulation axis (55,57) during articulation of articulation section (70). As shown inFIG.9, multi-planar articulation joint (65) is positioned to align lumens (91,93,95) along first articulation axis (55) such that first articulation axis (55) intersects longitudinal axis (61) at first point (P1) at a central lumen (93). One or more lumens (91,95) are then each radially offset from first point (P1) at a predetermined distance. Accordingly, multi-planar articulation joint (65) maintains this radial space between the one or more lumens (91,95) and first point (P1) at the predetermined distance as articulation section (70) is deflected from a straight configuration with articulation section (70) aligned along longitudinal axis (61) to a deflected configuration with articulation section (70) pivoted about first articulation axis (55) to deflect end effector (16) upwardly and/or downwardly along the first plane relative to longitudinal axis (61) (seeFIGS.5A-5B). As shown inFIG.11, multi-planar articulation joint (65) is positioned to align lumens (91,93,95) along second articulation axis (57) such that second articulation axis (57) intersects longitudinal axis (61) at second point (P2) at central lumen (93). One or more lumens (91,95) are then each radially offset from second point (P2) at a predetermined distance. Accordingly, multi-planar articulation joint (65) maintains this radial space between the one or more lumens (91,95) and second point (P2) at the predetermined distance as articulation section (70) is deflected from a straight configuration with articulation section (70) aligned along longitudinal axis (61) to a deflected configuration with articulation section (70) pivoted about second articulation axis (57) to deflect end effector (16) outwardly and/or inwardly along the second plane relative to longitudinal axis (61) (seeFIGS.6A-6B). With elongate members (90.92,94) (seeFIG.4) positioned through lumens (91,93,95), multi-planar articulation joint (65) is thereby configured to maintain the radially spaced relationship between elongate members (90,92,94) (seeFIG.30) at each articulation axis (55,57) during articulation of articulation section (70). FIG.12shows multi-planar articulation joint (65) in more detail. As shown in the present example, distal articulation joint interface (72b) is similar to proximal articulation joint interface (72a), but is positioned in a reversed direction and orientated about 90 degrees clockwise relative to proximal articulation joint interface (72a). Second articulation joint member (82b) is also similar to first articulation joint member (82a), but is positioned in a reversed direction and oriented about 90 degrees clockwise relative to first articulation joint member (82a). Accordingly, multi-planar articulation joint (65) is configured to support elongate members (90,92,94) to spiral in shape about 90 degrees in the collective helical configuration from a relatively horizontal orientation to a relatively vertical orientation through multi-planar articulation joint (65), but any other suitable angles for accommodating various deflections may be similarly used. While proximal articulation joint interface (72a) and first articulation joint member (82a) are discussed in more detail below, it should be noted that the discussion also applies to distal articulation joint interface (72b) and second articulation joint member (82b) respectively such that a like number with a differing letter indicates a like feature. FIGS.13-16show proximal articulation joint interface (72a) comprising a generally cylindrical body (74a) having a pair of arms (76a) extending outwardly from body (74a) on opposing sides of body (74a). Each arm (76a) includes an arcuate recess (75a) extending inwardly within arm (76a). Body (74a) further includes a pair of channels (73a) extending inwardly within body (74a) adjacent to each arm (76a) on opposing sides of body (74a). Each channel (73a) is curved and includes an opening (71a) extending through a top and bottom portion of each channel (73a). Body (74a) further comprises a protrusion (78a) extending outwardly from body (74a) adjacent to respective channel (73a). In the present example, protrusion (78a) has a generally triangular shape, but any other suitable shape may be used. A curved indentation (79a) is then positioned between protrusion (78a) and the opposing channel (73a) on body (74a). A plurality of conduits (77a) extend longitudinally through a central portion of body (74a) such that conduits (77a) are aligned with recesses (75a) of arms (76a). As shown in the present example, one conduit (77a) is positioned through protrusion (78a) and the remaining two conduits (77a) are positioned through indentation (79a). FIGS.17-24show first articulation joint member (82a) comprising a body (84a) having a collar (99a) positioned about a central portion of body (84a). Body (84a) comprises a first plate (86a) extending outwardly from collar (99a) and a second plate (88a) extending outwardly from collar (99a) in an opposing direction from first plate (86a). First plate (86a) is generally elliptical and defines a channel (96a) extending within first plate (86a) about a circumference of first plate (86a). A generally cylindrical knob (81a) extends outwardly from an exterior surface of first plate (86a). Second plate (88a) is generally elliptical and defines a channel (98a) extending within second plate (88a) about a circumference of second plate (88a). A generally cylindrical knob (83a) extends outwardly from an exterior surface of second plate (88a). Second plate (88a) is oriented about 90 degrees clockwise relative to first plate (86a) such that an end of channel (98a) of second plate (88a) is aligned with an end of channel (96a) of first plate (86a). An opening (97a) is then positioned through collar (99a) to connect channel (98a) of second plate (88a) with channel (96a) of first plate (98a). Body (84a) of first articulation joint member (82a) further comprises a first protrusion (85a) extending inwardly from an interior surface of first plate (86a) and a second protrusion (87a) extending inwardly from an interior surface of second plate (88a). Second protrusion (87a) is oriented about 90 degrees clockwise relative to first protrusion (85a) such that second protrusion (87a) is connected with first protrusion (85a) at a central portion of body (84a). Each protrusion (85a,87a) has a curved end portion. Collar (99a) defines a wedge portion between first protrusion (85a) and first plate (86a). A plurality of channels (91a,93a,95a) extend continuously from the end portion of first protrusion (85a) to the end portion of second protrusion (87a). As each channel (91a,93a,95a) extends from first protrusion (85a) to second protrusion (87a), each channel (91a,95a) spirals around channel (93a) along the centerline therethrough about 90 degrees. Accordingly, channels (91a,93a,95a) are aligned horizontally relative to each other on first protrusion (85a) and are aligned vertically relative to each other on second protrusion (87a). Channels (91a,93a,95a) of articulation joint member (82a) are thereby configured to receive elongate members (90,92,94), as shown inFIGS.25-26. Each channel (91a,93a,95a) receives an elongate member (90,92,94). Elongate members (90,94) thereby spiral about 90 degrees around elongate member (92) through channels (91a,93a,95a) such that elongate members (90,92,94) are aligned horizontally relative to each other on first protrusion (85a) and are aligned vertically relative to each other on second protrusion (87a). FIGS.27-28show first articulation joint member (82a) assembled with second articulation joint member (82b) to form articulation joint core (80). As shown, second articulation joint member (82b) is oriented in an opposing direction and reoriented about 90 degrees clockwise relative to first articulation joint member (82a). This aligns first protrusion (85b) of second articulation joint member (82b) with second protrusion (87a) of first articulation joint member (82a). Accordingly, channel (91a) of first articulation joint member (82a) is aligned with channel (91b) of second articulation joint member (82b) to form lumen (91). Channel (93a) of first articulation joint member (82a) is aligned with channel (93b) of second articulation joint member (82b) to form lumen (93). Channel (95a) of first articulation joint member (82a) is aligned with channel (95b) of second articulation joint member (82b) to form lumen (95). Channel (96a) of first articulation joint member (82a) is also aligned with channel (96b) of second articulation joint member (82b) and channel (98a) of first articulation joint member (82a) is also aligned with channel (98b) of second articulation joint member (82b) such that channels (96a,96b,98a,98b) extend continuously about a perimeter of articulation joint core (80). Referring toFIGS.4-28, articulation joint core (80) is assembled with proximal and distal articulation joint interfaces (72a,72b) such that proximal articulation joint interface (72a) is coupled proximally to articulation joint core (80) and distal articulation joint interface (72b) is coupled distally to distal articulation joint core (80). For instance, a knob (81a) of first articulation joint member (82a) is inserted within recess (75a) of proximal articulation joint interface (72a) and knob (83b) of second articulation joint member (82b) is inserted within the opposing recess (75a) of proximal articulation joint interface (72a). Knobs (81a,83b) are rotatable within recesses (75a) to thereby allow articulation joint core (80) to pivot relative to proximal articulation joint interface (72a) about first articulation axis (55). First plate (86a) of first articulation joint member (82a) is inserted within channel (73a) of proximal articulation joint interface (72a) and second plate (88b) of second articulation joint member (82b) within the opposing channel (73a) of proximal articulation joint interface (72a). Openings (71a) of proximal articulation joint interface (72a) are thereby aligned with channel (96a) of first articulation joint member (82a) and channel (98b) of second articulation joint member (82b). The curved configurations of plates (86a,88b) and channels (73a) allow plates (86a,88b) of articulation joint core (80) to rotate smoothly within channels (73a) as articulation joint core (80) is pivoted about first articulation axis (55). First protrusion (85a) of first articulation joint member (82a) and second protrusion (87b) of second articulation joint member (82b) are inserted within indentation (79a) of proximal articulation joint interface (72a) and protrusion (78a) of proximal articulation joint interface (72a) is inserted between first protrusion (85a) and first plate (86a) of first articulation joint member (82a). Accordingly, conduits (77a) of proximal articulation joint interface (72a) are aligned to further define lumens (91,93,95) extending through articulation joint core (80). On the distal end portion of articulation joint core (80), knob (83a) of first articulation joint member (82a) is inserted within recess (75b) of distal articulation joint interface (72b) and knob (81b) of second articulation joint member (82b) is inserted within the opposing recess (75b) of distal articulation joint interface (72b). Knobs (81b,83a) are rotatable within recesses (75b) to thereby allow distal articulation joint interface (72b) to pivot relative to articulation joint core (80) about second articulation axis (57). Second plate (88a) of first articulation joint member (82a) is inserted within channel (73b) of distal articulation joint interface (72b) and first plate (86b) of second articulation joint member (82b) within the opposing channel (73b) of distal articulation joint interface (72b). Openings (71b) of distal articulation joint interface (72b) are thereby aligned with channel (98a) of first articulation joint member (82a) and channel (96b) of second articulation joint member (82b). The curved configurations of plates (86b,88a) and channels (73b) allow plates (86b,88a) of articulation joint core (80) to rotate smoothly within channels (73b) as distal articulation joint interface (72b) is pivoted about second articulation axis (57). First protrusion (85b) of second articulation joint member (82b) and second protrusion (87a) of first articulation joint member (82a) are inserted within indentation (79b) of distal articulation joint interface (72b) and protrusion (78b) of distal articulation joint interface (72b) is inserted between first protrusion (85b) and first plate (86b) of second articulation joint member (82b). Accordingly, conduits (77b) of distal articulation joint interface (72b) are aligned to further define lumens (91,93,95) extending through articulation joint core (80). Elongate members (90,92,94) are respectively positioned through conduits (77a) of proximal articulation joint interface (72a), through lumens (91,93,95) of articulation joint core (80), and through conduits (77b) of distal articulation joint interface (72b) to operatively connect elongate members (90,92,94) with end effector (16) for operation of end effector (16). As elongate members (90,92,94) distally extend through articulation joint core (80), elongate members (90,92,94) are oriented along first articulation axis (55) and elongate members (90,94) spiral around elongate member (92) to be collectively oriented along second articulation axis (57) via the collective helical configuration of lumens (91,93,95). Referring toFIG.7, the curved end portions of first protrusion (85b) of second articulation joint member (82b) and second protrusion (87a) of first articulation joint member (82a) are aligned at elongate members (90,92) proximal to distal articulation joint interface (72b) to support such elongate members (90,92) in a lobe style configuration. This may allow for distributed articulation of elongate members (90,92) between articulation joint core (80) and distal articulation joint interface (72b). The curved end portions of first protrusion (85a) of first articulation joint member (82a) and second protrusion (87b) of second articulation joint member (82b) may also be aligned at elongate members (90,92) distal to proximal articulation joint interface (72a) to support such elongate members (90,92) in a lobe style configuration. Referring toFIG.8, the wedge portions of collars (99a,99b) of first and second articulation joint members (82a,82b) are aligned at elongate member (94) proximal to distal articulation joint interface (72b) to support such elongate member (94) in a wedge style configuration. This may allow for a more concentrated articulation of elongate member (94) between articulation joint core (80) and distal articulation joint interface (72b). The wedge end portions of collars (99a,99b) may also be aligned at elongate member (94) distal to proximal articulation joint interface (72a) to support such elongate member (94) in a wedge style configuration. By way of example only, articulation section (64) may alternatively or additionally be configured in accordance with one or more teachings of U.S. Pat. No. 9,402,682, entitled “Articulation Joint Features for Articulating Surgical Device,” issued Aug. 2, 2016, the disclosure of which is incorporated by reference herein. As another merely illustrative example, articulation section (64) may alternatively or additionally be configured in accordance with one or more teachings of U.S. Pat. No. 9,393,037, issued Jul. 19, 2016, entitled “Surgical Instruments with Articulating Shafts,” the disclosure of which is incorporated by reference herein and U.S. Pat. No. 9,095,367, issued Aug. 4, 2015, entitled “Flexible Harmonic Waveguides/Blades for Surgical Instruments,” the disclosure of which is incorporated by reference herein. In addition to or in lieu of the foregoing, articulation section (64) and/or may be constructed and/or operable in accordance with at least some of the teachings of U.S. Pat. No. 10,034,683, entitled “Ultrasonic Surgical Instrument with Rigidizing Articulation Drive Members,” issued on Jul. 31, 2018. Alternatively, articulation section (64) may be constructed and/or operable in any other suitable fashion. D. Alternative Exemplary End Effector and Shaft Assembly Having an Articulation Section with a Second Exemplary Multi-Planar Articulation Joint FIG.29shows an alternative end effector (116) and shaft assembly (114) for use with base assembly (12) (seeFIG.1) described above such that like numbers below indicate like features described above in greater detail. End effector (116) of the present example is similar to end effector (16) (seeFIG.1) described above in that end effector (116) includes an upper jaw (124) and a lower jaw (126) for clamping tissue. In the illustrated embodiment, upper jaw (124) is operable to selectively pivot toward and away from lower jaw (126) to selectively clamp tissue between upper jaw (124) and lower jaw (126). A pair of arms (121) extend transversely from upper jaw (124) and are pivotally secured to another portion of shaft assembly (114) configured to longitudinally slide to pivot upper jaw (124) between a closed position and an open position. End effector (116) of the present example is operable to seal tissue by applying radiofrequency (RF) electrosurgical energy to the tissue. An example of a surgical instrument that is operable to seal tissue by applying RF energy to the tissue is the ENSEAL® Tissue Sealing Device by Ethicon Endo-Surgery, Inc., of Cincinnati, Ohio. Further examples of such devices and related concepts are disclosed in U.S. Pat. No. 6,500,176 entitled “Electrosurgical Systems and Techniques for Sealing Tissue,” issued Dec. 31, 2002, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 7,112,201 entitled “Electrosurgical Instrument and Method of Use,” issued Sep. 26, 2006, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 7,125,409, entitled “Electrosurgical Working End for Controlled Energy Delivery,” issued Oct. 24, 2006, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 7,169,146 entitled “Electrosurgical Probe and Method of Use,” issued Jan. 30, 2007, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 7,186,253, entitled “Electrosurgical Jaw Structure for Controlled Energy Delivery,” issued Mar. 6, 2007, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 7,189,233, entitled “Electrosurgical Instrument,” issued Mar. 13, 2007, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 7,220,951, entitled “Surgical Sealing Surfaces and Methods of Use,” issued May 22, 2007, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 7,309,849, entitled “Polymer Compositions Exhibiting a PTC Property and Methods of Fabrication,” issued Dec. 18, 2007, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 7,311,709, entitled “Electrosurgical Instrument and Method of Use,” issued Dec. 25, 2007, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 7,354,440, entitled “Electrosurgical Instrument and Method of Use,” issued Apr. 8, 2008, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 7,381,209, entitled “Electrosurgical Instrument,” issued Jun. 3, 2008, the disclosure of which is incorporated by reference herein. While the present example of end effector (116) includes jaws (124,126) configured to grip tissue for manipulation thereof, it will be appreciated that any such end effector for use with tissue in a surgical procedure may be similarly incorporated into surgical instrument (10) (seeFIG.1). Indeed, other suitable configurations for end effector will be apparent to one with ordinary skill in the art in view of the teachings herein, including, but not limited to, an endocutter, grasper, cutter, stapler, clip applier, access device, needle driver, scissors, retractor, spatula, hook, and energy delivery device using ultrasonic vibration, RF, laser, etc. The invention is thus not intended to be limited to end effector (116) shown in the present example. More particularly, and by way of example only, end effector (116) may alternatively or additionally be configured in accordance with one or more teachings described in U.S. Pat. Pub. No. 2019/0125464, entitled “Robotic Surgical Tool with Manual Release Lever,” published on May 2, 2019, issued as U.S. Pat. No. 10,624,709; U.S. Pat. Pub. No. 2012/0292367, entitled “Robotically-Controlled End Effector,” published on Nov. 11, 2012, now abandoned; U.S. Pat. No. 9,314,308, entitled “Robotic Ultrasonic Surgical Device With Articulating End Effector,” issued on Apr. 19, 2016; and U.S. Pat. No. 10,039,548, entitled “Clip Applier Adapted for Use with a Surgical Robot,” issued on Aug. 7, 2018. Shaft assembly (114) of the present example includes an alternative exemplary articulation section (170) having a second exemplary multi-planar articulation joint (165) configured to deflect end effector (116) through a plurality of planes. Referring toFIGS.29-30, multi-planar articulation joint (165) includes a proximal articulation joint interface (172a) extending distally from proximal shaft portion (60) a distal articulation joint interface (172b) extending proximally from distal shaft portion (62), and an articulation joint core (180) positioned between proximal and distal articulation joint interfaces (172a,172b). Articulation joint core (180) includes a first articulation joint member (182a) assembled with a second articulation joint member (182b) such that second articulation joint member (182b) is oriented about 90 degrees clockwise relative to first articulation joint member (182a) about longitudinal axis (61). Each of first and second articulation joint members (182a,182b) are thereby assembled to form articulation joint core (180), which is pivotable relative to longitudinal axis (61) of proximal shaft portion (60) to position end effector (116) in various positions about longitudinal axis (61) similar to articulation joint core (80) described above. In order to selectively drive multi-planar articulation joint (165), a plurality of cables (96) extend from base assembly (12) (seeFIG.1) to multi-planar articulation joint (165). In the present example, proximal articulation joint interface (172a) is coupled with proximal shaft portion (60) and distal articulation joint interface (172b) is coupled with distal shaft portion (62). Four such cables (96) extend through openings (171a) of proximal articulation joint interface (172a), through corresponding channels (196a,198a,196b,198b) (seeFIGS.47-48) and openings (197a,197b) (seeFIGS.47-48) of articulation joint core (180), and through openings (171b) of distal articulation joint interface (172b). Cables (96) thereby connect to distal articulation joint interface (172b) such that pulling on cables (96) on one side of multi-planar articulation joint (165) will selectively articulate multi-planar articulation joint (165). It will be appreciated that such cables (96) may be pulled in various combinations to achieve any desired articulation. Still other suitable configurations for articulating multi-planar articulation joint (165) will be apparent to one with ordinary skill in the art in view of the teachings herein. With respect toFIG.30, multi-planar articulation joint (165) further provides support and guidance for elongate members (202,204,206,208) extending through articulation section (170) that may couple components of base assembly (12) (seeFIG.1) and/or shaft assembly (114) (seeFIG.29) with end effector (116) (seeFIG.29) for operation of end effector (116) (seeFIG.29). For instance, one or more elongate members (202,204) may include cables acting in tension such that elongate member (202) may be used for pivoting upper jaw (124) into the closed position and elongate member (204) may be used for pivoting upper jaw (124) into the open position. Additionally, elongate member (206) may be configured to provide RF energy to end effector (116) and elongate member (208) may be configured as a knife rod for cutting tissue grasped within end effector (116). Still other suitable configurations for elongate members (202,204,206,208) will be apparent to one with ordinary skill in the art in view of the teachings herein. As shown inFIGS.30-31, multi-planar articulation joint (165) supports each of elongate members (202,204,206,208) along a continuous path offset relative to longitudinal axis (61) to provide smooth control of elongate members (202,204,206,208) that inhibits catching, kinking, over-extension, and/or over-compression of such elongate members (202,204,206,208) during articulation of articulation section (170), particularly when simultaneously deflecting end effector (116) (seeFIG.29) through multiple planes. Multi-planar articulation joint (165) may further help to inhibit wear of articulation section (170). To this end, multi-planar articulation joint (165) includes a proximal plate (130) positioned within a proximal portion of articulation joint core (180), a distal plate (140) positioned within a distal portion of articulation joint core (180), and a cap (150) positioned within distal articulation joint interface (172b) for receiving and supporting elongate members (202,204,206,208). In the illustrated embodiment, elongate members (206,208) are positioned within a multi-lumen assembly (200) to support elongate members (206,208) within plates (130,140) and cap (150). Multi-lumen assembly (200) in the present example has an elliptical body extending proximally from cap (150) through plates (130,140). Multi-lumen assembly (200) defines a pair of lumens (201,203) (seeFIG.32) extending through multi-lumen assembly (200) to receive elongate members (206,208). While multi-lumen assembly (200) is of a single, unitary construction and shown having two lumens to respectively receive two elongate members, any other suitable number of lumens can be used to receive any suitable number of elongate members within multi-lumen assembly (200). Plates (130,140), cap (150), and/or multi-lumen assembly (200) thereby support elongate members (202,204,206,208) to extend along a continuous path to maintain the spacing of elongate members (202,204,206,208) relative to each other throughout multi-planar articulation joint (165). While four elongate members (202,204,206,208) are shown in the present example, any other suitable number and/or configurations for elongate members (202,204,206,208) may be used. FIG.32shows multi-planar articulation joint (165) in more detail. As shown in the present example, distal articulation joint interface (172b) is substantially similar to proximal articulation joint interface (172a), but is positioned in a reversed direction and orientated about 90 degrees clockwise relative to proximal articulation joint interface (172a). Second articulation joint member (182b) is also substantially similar to first articulation joint member (182a), but is positioned in a reversed direction and oriented about 90 degrees clockwise relative to first articulation joint member (182a). Accordingly, multi-planar articulation joint (165) is configured to support elongate members (202,204,206,208) to maintain the spacing of elongate members (202,204,206,208) relative to each other through multi-planar articulation joint (165). While first articulation joint member (182a) is discussed in more detail below, it should be noted that the discussion also applies to second articulation joint member (182b) respectively such that a like number with a differing letter indicates a like feature. FIGS.33-34show proximal articulation joint interface (172a) comprising a generally cylindrical body (174a) having a pair of arms (176a) extending outwardly from body (174a) on opposing sides of body (174a). Each arm (176a) includes an arcuate recess (175a) extending inwardly within arm (176a). Body (174a) further includes a pair of channels (173a) extending inwardly within body (174a) adjacent to each arm (176a) on opposing sides of body (174a). Each channel (173a) is curved and includes an opening (171a) extending through top and bottom portions of each channel (173a). A curved protrusion (179a) is then positioned between the opposing channels (173a) on body (174a) and defines a conduit (177a) centrally therethrough. FIGS.35-36show first articulation joint member (182a) comprising a body (184a) having a collar (199a) positioned about a central portion of body (184a). Body (184a) comprises a first plate (186a) extending outwardly from collar (199a) and a second plate (188a) extending outwardly from collar (199a) in an opposing direction from first plate (186a). First plate (186a) is generally elliptical and defines a channel (196a) extending within first plate (186a) about a circumference of first plate (186a). A generally cylindrical knob (181a) extends outwardly from an exterior surface of first plate (186a) and a generally cylindrical recess (194a) extends inwardly from an interior surface of first plate (186a). Second plate (188a) is generally elliptical and defines a channel (198a) extending within second plate (188a) about a circumference of second plate (188a). A generally cylindrical knob (183a) extends outwardly from an exterior surface of second plate (188a) and a generally cylindrical recess (192a) extends inwardly from an interior surface of second plate (188a). Second plate (188a) is oriented about 90 degrees clockwise relative to first plate (186a) such that an end of channel (198a) of second plate (188a) is aligned with an end of channel (196a) of first plate (186a). An opening (197a) is then positioned through collar (199a) to connect channel (198a) of second plate (188a) with channel (196a) of first plate (198a). Body (184a) of first articulation joint member (182a) further comprises an arcuate surface (190a) extending along an interior surface of body (184a) between first and second plates (186a,188a). FIGS.37-38show proximal plate (130) comprising a generally circular body (132) and a pair of generally circular end plates (134,136) positioned on each side of body (132) transverse to body (132). Body (132) further defines a plurality of lumens (131,133,135) extending therethrough. As best seen inFIG.38, first lumen (131) and second lumen (133) are substantially circular with first lumen (131) being positioned downward and outward relative to second lumen (133). Third lumen (135) is substantially elliptical and positioned obliquely within body (132) adjacent to first and second lumens (131,133). FIGS.39-40show distal plate (140) comprising a generally circular body (142) and a pair of generally circular end plates (144,146) positioned on a top and bottom surface of body (142) transverse to body (142). Body (142) further defines a plurality of lumens (141,143,145) extending therethrough. As best seen inFIG.40, first lumen (141) and second lumen (143) are substantially circular with first lumen (141) being positioned downward and outward relative to second lumen (143). Third lumen (145) is substantially elliptical and positioned obliquely within body (142) adjacent to first and second lumens (141,143). Accordingly, lumens (141,143,145) of distal plate (140) are positioned to align with lumens (131,133,135) of proximal plate (130). FIGS.41-44show cap (150) comprising a generally circular body (152). Body (152) defines a plurality of lumens (151,153,155) extending therethrough. As best seen inFIG.43, first lumen (151) and second lumen (153) are substantially circular with first lumen (151) being positioned downward and outward relative to second lumen (153). Third lumen (155) is substantially elliptical and positioned obliquely within body (152) adjacent to first and second lumens (151,153). Accordingly, lumens (151,153,155) of cap (150) are positioned to align with lumens (131,133,135) of proximal plate (130) and lumens (141,143,145) of distal plate (140). Cap (150) further comprises a generally cylindrical protrusion (154) extending proximally from body (152) that has a smaller outer diameter than body (152). A pair of flanges (156) then extend radially outward from opposing surfaces of protrusion (154) to the outer diameter of body (152). A generally elliptical recess (157) extends through protrusion (154) to body (152) to position first and second lumens (151,153) within recess (157). Third lumen (153) extends continuously through body (152) and protrusion (154) adjacent to recess (157). FIGS.45-46show distal articulation joint interface (172b) comprising a generally cylindrical body (174b) having a pair of arms (176b) extending outwardly from body (174b) on opposing sides of body (174b). Each arm (176b) includes an arcuate recess (175b) extending inwardly within arm (176b). Body (174b) further includes a channel (173b) extending inwardly within body (174b) between each arm (176b). Channel (173b) includes a plurality of openings (171b) extending through a top and bottom portion of each side portion of channel (173b). A conduit (177b) extends through a central portion of channel (173b), and a pair of cut-outs (179b) extend radially outward from conduit (177b) within channel (173b). FIGS.47-48show first articulation joint member (182a) assembled with second articulation joint member (182b) to form articulation joint core (180). As shown, second articulation joint member (182b) is oriented in an opposing longitudinal direction and reoriented about 90 degrees clockwise relative to first articulation joint member (182a). This aligns arcuate surface (190a) of first articulation joint member (182a) with arcuate surface (190b) of second articulation joint member (182b) to form lumen (190). As shown inFIG.49, proximal plate (130) is positioned within a proximal portion of articulation joint core (180) such that end plate (136) of proximal plate (130) is received within recess (192b) of second plate (188b) of second articulation joint member (182b) and end plate (134) (seeFIG.37) of proximal plate (130) is received within recess (194a) (seeFIG.36) of first plate (186a) of first articulation joint member (182a). This positions body (132) of proximal plate (130) between first plate (186a) of first articulation joint member (182a) and second plate (188b) of second articulation joint member (182b) to align lumens (131,133,135) (seeFIG.38) of body (132) with lumen (190) of articulation joint core (180). Distal plate (140) is positioned within a distal portion of articulation joint core (180) such that end plate (144) (seeFIG.39) of distal plate (140) is received within recess (192a) (seeFIG.36) of second plate (188a) of first articulation joint member (182a) and end plate (146) of distal plate (140) is received within recess (194b) of first plate (186b) of second articulation joint member (182b). This positions body (142) of distal plate (140) between first plate (186b) of second articulation joint member (182b) and second plate (188a) of first articulation joint member (182a) to align lumens (141,143,145) (seeFIG.40) of body (142) with lumen (190) of articulation joint core (180). Accordingly, articulation joint core (180) is configured to position body (132) of proximal plate (130) at the first articulation axis (55) with end plates (134,136) (seeFIG.38) positioned along first articulation axis (55) and body (142) of distal plate (140) at the second articulation axis (57) with end plates (144,146) (seeFIG.40) of distal plate (140) along second articulation axis (57). FIGS.50-51show cap (150) inserted within conduit (177b) of distal articulation joint interface (172b) to form distal articulation joint assembly (167). Cap (150) is positioned within conduit (177b) such that each protrusion (156) of cap (150) is inserted within a cut-out (179b) of distal articulation joint interface (172b) to maintain the rotational position of cap (150) relative to distal articulation joint interface (172b). In use, referring toFIGS.30-32, articulation joint core (180) with proximal and distal plates (130,140) is assembled with proximal joint interface (172a) and distal articulation joint assembly (167). Accordingly, proximal articulation joint interface (172a) is coupled proximally to articulation joint core (180) and distal articulation joint assembly (167) is coupled distally to distal articulation joint core (180). For instance, a knob (181a) of first articulation joint member (182a) is inserted within recess (175a) of proximal articulation joint interface (172a) and knob (183b) (seeFIG.48) of second articulation joint member (182b) is inserted within the opposing recess (175a) of proximal articulation joint interface (172a). Knobs (181a,183b) (seeFIG.48) are rotatable within respective recesses (175a) to thereby allow articulation joint core (180) to pivot relative to proximal articulation joint interface (172a) about first articulation axis (55). First plate (186a) of first articulation joint member (182a) is inserted within channel (173a) of proximal articulation joint interface (172a) and second plate (188b) of second articulation joint member (182b) within the opposing channel (173a) of proximal articulation joint interface (172a). Opening (177a) (seeFIG.34) of proximal articulation joint interface (172a) is thereby aligned with lumen (190) (seeFIG.48) of articulation joint core (180). The curved configurations of plates (186a,188b) and respective channels (173a) allow plates (186a,188b) of articulation joint core (180) to rotate smoothly within channels (173a) as articulation joint core (180) is pivoted about first articulation axis (55). On the distal end portion of articulation joint core (180), knob (183a) of first articulation joint member (182a) is inserted within recess (175b) of distal articulation joint interface (172b) and knob (181b) of second articulation joint member (182b) is inserted within the opposing recess (175b) of distal articulation joint interface (172b). Knobs (181b,183a) are rotatable within respective recesses (175b) to thereby allow distal articulation joint interface (172b) to pivot relative to articulation joint core (180) about second articulation axis (57). Second plate (188a) of first articulation joint member (182a) and first plate (186b) of second articulation joint member (182b) are inserted within respective channels (173b) of distal articulation joint interface (172b). Opening (177b) of distal articulation joint interface (172b) is thereby aligned with lumen (190) (seeFIG.48) of articulation joint core (180). The curved configurations of plates (186b,188a) and respective channels (173b) allow plates (186b,188a) of articulation joint core (180) to rotate smoothly within channels (173b) as distal articulation joint interface (172b) is pivoted about second articulation axis (57). With continued reference toFIGS.30-32as well asFIGS.34,38,40,44, and48, elongate members (202,204,206,208) are respectively positioned through conduits (177a) of proximal articulation joint interface (172a), through lumens (131,133,135) of proximal plate (130), through lumen (190) of articulation joint core (180), through lumens (141,143,145) of distal plate (140), and through lumens (151,153,155) of cap (150) within conduit (177b) of distal articulation joint interface (172b). Thereby, elongate members (202,204,206,208) operatively extend from base assembly (12) (seeFIG.1) and connect with end effector (116) (seeFIG.29) for operation of end effector (116) (seeFIG.29). In the illustrated embodiment, elongate member (202) is configured to extend through lumen (131) of proximal plate (130), lumen (141) of distal plate (140), and lumen (151) of cap (150) such that elongate member (202) extends continuously through articulation joint core (180) along an axis that is substantially parallel with and offset from longitudinal axis (61) in the straight configuration. Elongate member (204) is configured to extend through lumen (133) of proximal plate (130), lumen (143) of distal plate (140), and lumen (153) of cap (150) such that elongate member (204) extends continuously through articulation joint core (180) along an axis that is substantially parallel with and offset from longitudinal axis (61) and elongate member (202) in the straight configuration. Elongate member (206) is configured to extend through lumen (203) of multi-lumen assembly (200) and elongate member (208) is configured to extend through lumen (201) of multi-lumen assembly (200) respectively. Multi-lumen assembly (200) is then sized to be inserted within lumen (135) of proximal plate (130), lumen (145) of distal plate (140), and lumen (155) of cap (150) such that elongate members (206,208) extend continuously through articulation joint core (180) along an axis that is substantially parallel with and offset from longitudinal axis (61) and elongate members (202,204) in the straight configuration. In some versions, multi-planar articulation joint (165) is configured to inhibit elongate members (206,208) from translating within multi-planar articulation joint (165). Referring toFIGS.52-53, multi-planar articulation joint (165) is configured to maintain the spaced relationship between elongate members (202,204,206,208) (seeFIG.30) at each articulation axis (55,57) during articulation of articulation section (170). As shown inFIG.52, proximal plate (130) is positioned along first articulation axis (55) such that first articulation axis (55) intersects longitudinal axis (61) at first point (P1) at a central portion of proximal plate (130). One or more lumens (131,133,135) of proximal plate (130) are each radially offset from first point (P1) at a predetermined distance. Accordingly, proximal plate (130) maintains this radial space between the one or more lumens (131,133,135) and first point (P1) at the predetermined distance as articulation section (170) is deflected from a straight configuration with articulation section (170) aligned along longitudinal axis (61) to a deflected configuration with articulation section (170) pivoted about first articulation axis (55) to deflect end effector (116) upwardly and/or downwardly along the first plane relative to longitudinal axis (61). As shown inFIG.53, distal plate (140) is positioned along second articulation axis (57) such that second articulation axis (57) intersects longitudinal axis (61) at second point (P2) at a central portion of distal plate (140). One or more lumens (141,143,145) of distal plate (140) are each radially offset from second point (P2) at a predetermined distance. Accordingly, distal plate (140) maintains this radial space between the one or more lumens (141,143,145) and second point (P2) at the predetermined distance as articulation section (170) is deflected from a straight configuration with articulation section (170) aligned along longitudinal axis (61) to a deflected configuration with articulation section (170) pivoted about second articulation axis (57) to deflect end effector (116) outwardly and/or inwardly along the second plane relative to longitudinal axis (61). With (202,204,206,208) (seeFIG.30) positioned through lumens (131,133,135,141,143,145), multi-planar articulation joint (165) is thereby configured to maintain the radially spaced relationship between elongate members (202,204,206,208) (seeFIG.30) at each articulation axis (55,57) during articulation of articulation section (170). Still other suitable configurations for multi-planar articulation joint (165) will be apparent to one with ordinary skill in the art in view of the teachings herein. E. Alternative Exemplary Shaft Assembly Having an Articulation Section with a Third Exemplary Multi-Planar Articulation Joint FIG.54shows an alternative shaft assembly (214) for use with base assembly (12) (seeFIG.1) described above such that like numbers below indicate like features described above in greater detail. Shaft assembly (214) of the present example includes an alternative exemplary articulation section (270) having a third exemplary multi-planar articulation joint (265) configured to deflect end effector (116) through a plurality of planes. Referring toFIGS.54-55, multi-planar articulation joint (265) includes a proximal articulation joint interface (272a) extending distally from proximal shaft portion (60), a distal articulation joint interface (272b) extending proximally from distal shaft portion (62), and articulation joint core (180) positioned between proximal and distal articulation joint interfaces (272a,272b). As discussed above, articulation joint core (180) includes first articulation joint member (182a) assembled with second articulation joint member (182b) such that second articulation joint member (182b) is oriented about 90 degrees clockwise relative to first articulation joint member (182a) about longitudinal axis (61). Each of first and second articulation joint members (182a,182b) are thereby assembled to form articulation joint core (180), which is pivotable relative to longitudinal axis (61) of proximal shaft portion (60) to position end effector (116) in various positions about longitudinal axis (61) similar to articulation joint core (80) described above. In order to selectively drive multi-planar articulation joint (265), cables (96) extend from base assembly (12) (seeFIG.1) to multi-planar articulation joint (265). In the present example, proximal articulation joint interface (272a) is coupled with proximal shaft portion (60) and distal articulation joint interface (272b) is coupled with distal shaft portion (62). Four such cables (96) extend through openings (271a) of proximal articulation joint interface (272a), through corresponding channels (196a,198a,196b,198b) (seeFIGS.47-48) and openings (197a,197b) (seeFIGS.47-48) of articulation joint core (180), and through openings (271b) of distal articulation joint interface (272b). Cables (96) thereby connect to distal articulation joint interface (272b) such that pulling on cables (96) on one side of multi-planar articulation joint (265) will selectively articulate multi-planar articulation joint (265). It will be appreciated that such cables (96) may be pulled in various combinations to achieve any desired articulation. Still other suitable configurations for articulating multi-planar articulation joint (265) will be apparent to one with ordinary skill in the art in view of the teachings herein. With respect toFIGS.54-55, multi-planar articulation joint (265) further provides support and guidance for elongate members (302,304,306,308) extending through articulation section (270) that may couple components of base assembly (12) (seeFIG.1) and/or shaft assembly (214) with end effector (116) for operation of end effector (116). For instance, one or more elongate members (302,304) may include cables acting in tension such that elongate member (302) may be used for pivoting upper jaw (124) into the closed position and elongate member (304) may be used for pivoting upper jaw (124) into the open position. Additionally, elongate member (306) may be configured to provide RF energy to end effector (116) and elongate member (308) may be configured as a knife rod for cutting tissue grasped within end effector (116). Still other suitable configurations for elongate members (302,304,306,308) will be apparent to one with ordinary skill in the art in view of the teachings herein. As shown inFIGS.55-56, multi-planar articulation joint (265) supports each of elongate members (302,304,306,308) along a continuous path offset relative to longitudinal axis (61) (seeFIG.54) to provide smooth control of elongate members (302,304,306,308) that inhibits catching, kinking, over-extension, and/or over-compression of such elongate members (302,304,306,308) during articulation of articulation section (270), particularly when simultaneously deflecting end effector (116) (seeFIG.54) through multiple planes. In addition, this continuous path followed by elongate members (302,304,306,308) is helical such that multi-planar articulation joint (265) of the present example supports a pair of elongate members (304,308) to further inhibit over-extension and/or over-compression as will be discussed below in greater detail. Multi-planar articulation joint (265) may further help to inhibit wear of articulation section (270). To this end, multi-planar articulation joint (265) includes a proximal plate (230) positioned within a proximal portion of articulation joint core (180), a distal plate (240) positioned within a distal portion of articulation joint core (180), and a support sleeve (241) having multi-lumen assembly (258) and a cap (250) positioned within distal articulation joint interface (272b) for receiving and supporting elongate members (302,304,306,308). In the illustrated embodiment, elongate members (302,304,306,308) are supported by multi-lumen assembly (258) through plates (230,240) such that plates (230,240) and cap (250) support elongate members (302,304,306,308) along a continuous path to maintain the spacing of elongate members (302,304,306,308) relative to each other throughout multi-planar articulation joint (265). While four elongate members (302,304,306,308) are shown in the present example, any other suitable number and/or configurations for elongate members (302,304,306,308) may be used. FIG.57shows multi-planar articulation joint (265) in more detail. As shown in the present example, distal articulation joint interface (272b) is substantially similar to proximal articulation joint interface (272a), but is positioned in a reversed direction and orientated about 90 degrees clockwise relative to proximal articulation joint interface (272a). Second articulation joint member (182b) is also substantially similar to first articulation joint member (182a), but is positioned in a reversed direction and oriented about 90 degrees clockwise relative to first articulation joint member (182a). Accordingly, multi-planar articulation joint (265) is configured to support elongate members (302,304,306,308) to maintain the spacing of elongate members (302,304,306,308) relative to each other through multi-planar articulation joint (265). FIGS.58-59show proximal articulation joint interface (272a) comprising a generally cylindrical body (274a) having a pair of arms (276a) extending outwardly from body (274a) on opposing sides of body (274a). Each arm (276a) includes an arcuate recess (275a) extending inwardly within arm (276a). Body (274a) further includes a pair of channels (273a) extending inwardly within body (274a) adjacent to each arm (276a) on opposing sides of body (274a). Each channel (273a) is curved and includes an opening (271a) extending through top and bottom portions of each channel (273a). A curved protrusion (279a) is then positioned between the opposing channels (273a) on body (274a) and defines a conduit (277a) centrally therethrough. A pair of recesses (278a) extend through a top and bottom portion of conduit (277a). FIGS.60-61show proximal plate (230) comprising a generally circular body (232) and a pair of generally circular end plates (234,236) positioned on each side of body (232) transverse to body (232). Body (232) further defines a lumen (237) extending therethrough and having a pair of recesses (238) extending from a top and bottom portion of lumen (237). As best seen inFIG.61, lumen (237) has a generally cross-shaped configuration. FIGS.62-63show distal plate (240) comprising a generally circular body (242) and a pair of generally circular end plates (244,246) positioned on a top and bottom surface of body (242) transverse to body (242). Body (242) further defines a lumen (247) extending therethrough and having a pair of recesses (248) extending from each side portion of lumen (247). As best seen inFIG.63, lumen (247) has a generally cross-shaped configuration. FIGS.64-67show support sleeve (241) having a cap (250) comprising a generally circular body (252). Body (152) defines a plurality of lumens (261,263,266,268) (seeFIG.57) extending therethrough. Cap (250) further comprises a generally cylindrical protrusion (254) extending proximally from body (252) that has a smaller outer diameter than body (252). A pair of flanges (256) then extend radially outward from opposing surfaces of protrusion (254) to the outer diameter of body (252). Support sleeve (241) further comprises multi-lumen assembly (258) extending proximally from protrusion (254). Two of lumens (266,268) continuously extend from circular body (252) through multi-lumen assembly (258). Multi-lumen assembly (258) then defines a pair of recesses (262,264) extending along an outer surface of multi-lumen assembly (258) such that each recess (262,264) respectively aligns with the other two lumens (261,263) of circular body (252). While multi-lumen assembly (258) has a single, unitary construction defining two lumens (266,268) and two recesses (262,264) as shown, any other suitable number of lumens (266,268) and recesses (262,264) or alternative, multi-component assemblies may be used. Multi-lumen assembly (258) includes a distal portion (251), an intermediate portion (253), and a proximal portion (255). Distal portion (251) is positioned to orient lumens (266,268) generally horizontally relative to each other. Intermediate portion (253) then rotates lumens (266,268) about 90 degrees such that proximal portion (255) is positioned to orient lumens (266,268) generally vertically relative to each other. Accordingly, recesses (262,264) are oriented generally vertically relative to each other at distal portion (255) and generally horizontally relative to each other at proximal portion (251). FIGS.68-69show distal articulation joint interface (272b) comprising a generally cylindrical body (274b) having a pair of arms (276b) extending outwardly from body (274b) on opposing sides of body (274b). Each arm (276b) includes an arcuate recess (275b) extending inwardly within arm (276b). Body (274b) further includes a channel (273b) extending inwardly within body (274b) between each arm (276b). Channel (273b) includes a plurality of openings (271b) extending through a top and bottom portion of each side portion of channel (273b). A conduit (277b) extends through a central portion of channel (273b), and a pair of cut-outs (279b) extend radially outward from conduit (277b) within channel (273b).FIGS.70-71show cap (250) inserted within conduit (277b) (seeFIG.69) of distal articulation joint interface (272b) to form distal articulation joint assembly (267). Cap (250) is positioned within conduit (277b) (seeFIG.69) such that each protrusion (256) of cap (250) is inserted within a cut-out (279b) of distal articulation joint interface (272b) to maintain the rotational position of cap (250) relative to distal articulation joint interface (272b). As briefly above with respect toFIG.55with particular reference toFIGS.72-73, multi-planar articulation joint (265) supports the pair of elongate members (304,308) along a continuous helical path to provide smooth control of elongate members (304,308) that inhibits catching, kinking, over-extension, and/or over-compression of such elongate members (304,308) during articulation of articulation section (270), particularly when simultaneously deflecting end effector (116) (seeFIG.54) through multiple planes. Elongate members (304,308) of the present example are thus positioned on each articulation axis (55,57). In contrast, another pair of elongate member (302,306) of the present example are neither positioned on articulation axis (55) nor on articulation axis (57). Still, both pairs of elongate members (302,304,306,308) spiral thereabout within spiraling lumens (266,268) and recesses (262,264) as applicable. While two pairs of elongate members (302,304,306,308) are shown in the present example, any other suitable number and/or configurations for elongate members (302,304,306,308) may be used. Referring toFIG.72, a proximal portion of multi-planar articulation joint (65) is configured to laterally align lumens (266,268) to be offset from each other along and intersect with first articulation axis (55). Accordingly, as multi-planar articulation joint (265) pivots about first articulation axis (55), elongate members (304,308) are positioned along first articulation axis (55) such that elongate members (304,308) may articulate about first articulation axis (55) with multi-planar articulation joint (265). As elongate members (304,308) extend distally, lumens (266,268) support elongate members (304,308) within articulation section (270) to thereby laterally align elongate members (304,308) obliquely between first articulation axis (55) and second articulation axis (57). As elongate members (304,308) continue to extend distally, a distal portion of multi-planar articulation joint (265) is configured to laterally align lumens (266,268) to be offset from each other along second articulation axis (57), as shown inFIG.73. Thus, as multi-planar articulation joint (65) pivots about second articulation axis (57), elongate members (304,308) are positioned along and intersect with second articulation axis (57) such that elongate members (304,308) may articulate about second articulation axis (57). Multi-planar articulation joint (265) thereby supports elongate members (304,308) in a collective helical configuration to align elongate members (304,308) along the select articulation axis (55,57) for supporting and guiding translation of elongate members (304,308) during articulation while maintaining the spaced of each of elongate members (302,304,306,308) as discussed below in greater detail. In use, referring toFIGS.55-57, articulation joint core (180) with proximal and distal plates (230,240) is assembled with proximal joint interface (272a) and distal articulation joint assembly (267). Accordingly, proximal articulation joint interface (272a) is coupled proximally to articulation joint core (180) and distal articulation joint assembly (267) is coupled distally to distal articulation joint core (180). For instance, knob (181a) of first articulation joint member (182a) is inserted within recess (275a) of proximal articulation joint interface (272a) and knob (183b) (seeFIG.48) of second articulation joint member (182b) is inserted within the opposing recess (275a) of proximal articulation joint interface (272a). Knobs (181a,183b) (seeFIG.48) are rotatable within respective recesses (275a) to thereby allow articulation joint core (180) to pivot relative to proximal articulation joint interface (272a) about first articulation axis (55). First plate (186a) of first articulation joint member (182a) is inserted within channel (273a) of proximal articulation joint interface (272a) and second plate (188b) of second articulation joint member (182b) within the opposing channel (273a) of proximal articulation joint interface (272a). Opening (277a) (seeFIG.59) of proximal articulation joint interface (272a) is thereby aligned with lumen (190) (seeFIG.48) of articulation joint core (180). The curved configurations of plates (186a,188b) and respective channels (273a) allow plates (186a,188b) of articulation joint core (180) to rotate smoothly within channels (273a) as articulation joint core (180) is pivoted about first articulation axis (55). On the distal end portion of articulation joint core (180), knob (183a) of first articulation joint member (182a) is inserted within recess (275b) of distal articulation joint interface (272b) and knob (181b) (seeFIG.48) of second articulation joint member (182b) is inserted within the opposing recess (275b) of distal articulation joint interface (272b). Knobs (181b,183a) are rotatable within respective recesses (275b) to thereby allow distal articulation joint interface (272b) to pivot relative to articulation joint core (180) about second articulation axis (57). Second plate (188a) of first articulation joint member (182a) and first plate (186b) of second articulation joint member (182b) are inserted within channel (273b) (seeFIG.68) of distal articulation joint interface (272b). Opening (277b) (seeFIG.69) of distal articulation joint interface (272b) is thereby aligned with lumen (190) (seeFIG.48) of articulation joint core (180). The curved configurations of plates (186b,188a) and respective channel (273b) (seeFIG.68) allow plates (186b,188a) of articulation joint core (180) to rotate smoothly within channels (273b) (seeFIG.68) as distal articulation joint interface (272b) is pivoted about second articulation axis (57). With continued reference toFIGS.54-57as well asFIGS.48,59,61, and63-65, elongate members (302,304,306,308) are respectively positioned through conduit (277a) of proximal articulation joint interface (272a), through lumen (237) of proximal plate (230), through lumen (190) of articulation joint core (180), through lumen (247) of distal plate (240), and through lumens (261,263,266,268) of cap (250) within conduit (277b) of distal articulation joint interface (272b). Thereby, elongate members (302,304,306,308) operatively extend from base assembly (12) (seeFIG.1) and connect with end effector (116) for operation of end effector (116). In the illustrated embodiment, elongate member (302) is configured to extend along recess (264) of multi-lumen assembly (258) through bottom recess (238) of proximal plate (230), recess (248) of distal plate (240), and lumen (263) of cap (250) such that elongate member (302) extends continuously through articulation joint core (180) along an axis that is substantially parallel with and offset from longitudinal axis (61) in the straight configuration. Elongate member (304) is configured to extend through lumen (268) of multi-lumen assembly (258), through lumen (237) of proximal plate (230), lumen (247) of distal plate (240), and lumen (268) of cap (250) such that elongate member (304) extends continuously through articulation joint core (180) along an axis that is substantially parallel with and offset from longitudinal axis (61) and elongate member (302) in the straight configuration. Elongate member (306) is configured to extend along recess (262) of multi-lumen assembly (258) through top recess (238) of proximal plate (230), recess (248) of distal plate (240), and lumen (261) of cap (250) such that elongate member (306) extends continuously through articulation joint core (180) along an axis that is substantially parallel with and offset from longitudinal axis (61) and elongate members (302,304) in the straight configuration. Elongate member (308) is configured to extend through lumen (266) of multi-lumen assembly (258), through lumen (237) of proximal plate (230), lumen (247) of distal plate (240), and lumen (266) of cap (250) such that elongate member (308) extends continuously through articulation joint core (180) along an axis that is substantially parallel with and offset from longitudinal axis (61) and elongate members (302,304,306) in the straight configuration. In some versions, multi-planar articulation joint (265) is configured to inhibit one or more elongate members (302,304,306,308) from translating within multi-planar articulation joint (265). Referring toFIGS.72-73, multi-planar articulation joint (265) is configured to maintain the spaced relationship between elongate members (302,304,306,308) (seeFIG.55) at each articulation axis (55,57) during articulation of articulation section (270). As shown inFIG.72, proximal plate (230) is positioned along first articulation axis (55) such that first articulation axis (55) intersects longitudinal axis (61) at first point (P1) at a central portion of proximal plate (230). Recesses (262,264) and lumens (266,268) of multi-lumen assembly (258) (seeFIG.64) that support elongate members (302,304,306,308) are each radially offset from first point (P1) at a predetermined distance. Accordingly, proximal plate (230) and multi-lumen assembly (258) (seeFIG.64) maintain this radial space at first point (P1) at the predetermined distance as articulation section (270) is deflected from a straight configuration with articulation section (270) aligned along longitudinal axis (61) to a deflected configuration with articulation section (270) pivoted about first articulation axis (55) to deflect end effector (116) (seeFIG.54) upwardly and/or downwardly along the first plane relative to longitudinal axis (61). As shown inFIG.73, distal plate (240) is positioned along second articulation axis (57) such that second articulation axis (57) intersects longitudinal axis (61) at second point (P2) at a central portion of distal plate (240). Recesses (262,264) and lumens (266,268) of multi-lumen assembly (258) that support elongate members (302,304,306,308) are each radially offset from second point (P2) at a predetermined distance. Accordingly, distal plate (240) and multi-lumen assembly (258) (seeFIG.64) maintain this radial space at second point (P2) at the predetermined distance as articulation section (270) is deflected from a straight configuration with articulation section (270) aligned along longitudinal axis (61) to a deflected configuration with articulation section (270) pivoted about second articulation axis (57) to deflect end effector (116) (seeFIG.54) outwardly and/or inwardly along the second plane relative to longitudinal axis (61). With elongate members (302,304,306,308) positioned through recesses (262,264) and lumens (266,268), multi-planar articulation joint (265) is thereby configured to maintain the radially spaced relationship between elongate members (302,304,306,308) at each articulation axis (55,57) during articulation of articulation section (270). Still other suitable configurations for multi-planar articulation joint (265) will be apparent to one with ordinary skill in the art in view of the teachings herein. II. Exemplary Combinations The following examples relate to various non-exhaustive ways in which the teachings herein may be combined or applied. It should be understood that the following examples are not intended to restrict the coverage of any claims that may be presented at any time in this application or in subsequent filings of this application. No disclaimer is intended. The following examples are being provided for nothing more than merely illustrative purposes. It is contemplated that the various teachings herein may be arranged and applied in numerous other ways. It is also contemplated that some variations may omit certain features referred to in the below examples. Therefore, none of the aspects or features referred to below should be deemed critical unless otherwise explicitly indicated as such at a later date by the inventors or by a successor in interest to the inventors. If any claims are presented in this application or in subsequent filings related to this application that include additional features beyond those referred to below, those additional features shall not be presumed to have been added for any reason relating to patentability. Example 1 A surgical instrument, comprising: (a) an end effector; and (b) a shaft assembly, including: (i) a proximal shaft portion longitudinally extending along a proximal axis, (ii) a distal shaft portion longitudinally extending along a distal axis, wherein the end effector distally extends from the distal shaft portion, (iii) a first elongate member extending from the proximal shaft portion and toward the end effector, wherein the first elongate member is operatively connected to at least one of the distal shaft portion or the end effector and configured to be selectively moved, and (iv) an articulation section extending between the proximal and distal shaft portions and configured to articulate about a first articulation axis and about a second articulation axis distal of the first articulation axis to thereby respectively deflect the end effector along a first plane and a second plane; wherein the first articulation axis intersects the proximal axis at a first intersection point, wherein the second articulation axis intersects the distal axis at a second intersection point, and wherein the articulation section includes a first lumen radially offset at a predetermined distance from each of the proximal and distal axes at each of the first and second intersection points when the end effector is in a straight configuration with the distal axis longitudinally aligned with the proximal axis; wherein the first lumen movably supports the first elongate member therethrough such that the radial spacing of the first elongate member is maintained at the predetermined distance at each of the first and second intersection points when the end effector is deflected to a deflected configuration along at least one of the first and second planes. Example 2 The surgical instrument of Example 1, wherein the first elongate member intersects each of the first and second articulation axes for deflection of the end effector. Example 3 The surgical instrument of any one or more of Examples 1 through 2, wherein the first lumen spirals from the first articulation axis to the second articulation axis to define a helical lumen. Example 4 The surgical instrument of any one or more of Examples 1 through 3, wherein the shaft assembly further includes a second elongate member extending from the proximal shaft portion and toward the end effector, wherein the second elongate member is operatively connected to at least one of the distal shaft portion or the end effector and configured to be selectively moved, wherein the articulation section further includes a second lumen radially offset at a predetermined distance from each of the proximal and distal axes at each of the first and second intersection points when the end effector is in the straight configuration, wherein the second lumen movably supports the second elongate member therethrough such that the radial spacing of the second elongate member is maintained at the predetermined distance at each of the first and second intersection points when the end effector is deflected to the deflected configuration. Example 5 The surgical instrument of Example 4, wherein the second elongate member intersects each of the first and second articulation axes for deflection of the end effector. Example 6 The surgical instrument of any or more of Examples 4 through 5, wherein the first and second lumens are radially offset from each other. Example 7 The surgical instrument of any one or more of Examples 4 through 6, wherein the shaft assembly further includes a central elongate member extending from the proximal shaft portion and toward the end effector, wherein the central elongate member is operatively connected to at least one of the distal shaft portion or the end effector and configured to be selectively moved, wherein the articulation section further includes a central lumen aligned with each of the proximal and distal axes that longitudinally intersects each of the proximal and distal articulation axes, wherein the central lumen movably supports the central elongate member therethrough such that the central elongate member intersects each of the first and second articulation axes for deflection of the end effector. Example 8 The surgical instrument of Example 7, wherein each of the first and second lumens spirals around the central lumen from the first articulation axis to the second articulation axis to define a collective helical configuration. Example 9 The surgical instrument of Example 1, wherein the shaft assembly further includes a central elongate member extending from the proximal shaft portion and toward the end effector, wherein the central elongate member is operatively connected to at least one of the distal shaft portion or the end effector and configured to be selectively moved, wherein the articulation section further includes a central lumen aligned with each of the proximal and distal axes that longitudinally intersects each of the first and second articulation axes, wherein the central lumen movably supports the central elongate member therethrough such that the central elongate member intersects each of the distal and proximal articulation axes for deflection of the end effector, wherein the first lumen spirals around the central lumen from the proximal articulation axis to the distal articulation axis to define a collective helical configuration. Example 10 The surgical instrument of any one or more of Examples 1 through 9, wherein the articulation section includes multi-planar articulation joint including a proximal articulation joint interface coupled with the proximal shaft portion, a distal articulation joint interface coupled with the distal shaft portion, and an articulation joint core pivotally coupled between each of the proximal and distal joint interfaces respectively at the proximal articulation axis and the distal articulation axis. Example 11 The surgical instrument of Example 10, wherein the articulation joint core has a first articulation joint member and a second articulation joint member, and wherein the first and second articulation joint members collectively define the first lumen therebetween. Example 12 The surgical instrument of any one or more of Examples 10 through 11, wherein each of the proximal and distal articulation joint interfaces includes a body having a protrusion extending outwardly from the body, wherein the articulation joint core has a wedge portion, and wherein the protrusion aligns with the wedge portion to support the first elongate member in a wedge style configuration. Example 13 The surgical instrument of any one or more of Examples 10 through 11, wherein each of the proximal and distal articulation joint interfaces includes a body having an indentation extending inwardly within the body, wherein the articulation joint core has a protrusion, and wherein the indentation aligns with the protrusion to support the first elongate member in a lobe style configuration. Example 14 The surgical instrument of Example 1, wherein the articulation section includes a proximal plate defining the first lumen, wherein the proximal plate intersects the first articulation axis, wherein the articulation section further includes a distal plate defining a second lumen longitudinally aligned with the first lumen for movably supporting the first elongate member therethrough, wherein the distal plate intersects the second articulation axis. Example 15 The surgical instrument of Example 14, wherein the shaft assembly further includes a second elongate member extending from the proximal shaft portion and toward the end effector, wherein the second elongate member is operatively connected to at least one of the distal shaft portion or the end effector and configured to be selectively moved, wherein the proximal plate further includes a third lumen radially offset at a predetermined distance from each of the proximal and distal axes at each of the first and second intersection points when the end effector is in the straight configuration, wherein the third lumen movably supports the second elongate member therethrough such that the radial spacing of the second elongate member is maintained at the predetermined distance at each of the first and second intersection points when the end effector is in the deflected position, wherein the distal plate further includes a fourth lumen longitudinally aligned with the third lumen, wherein the fourth lumen movably supports the second elongate member therethrough such that the radial spacing of the second elongate member is maintained at the predetermined distance at each of the first and second intersection points when the end effector is in the deflected position. Example 16 The surgical instrument of Example 14, wherein the shaft assembly further includes a second elongate member extending from the proximal shaft portion and toward the end effector, wherein the second elongate member is operatively connected to at least one of the distal shaft portion or the end effector and configured to be selectively moved, wherein the articulation section further includes a multi-lumen assembly extending through the first lumen of the proximal plate and the second lumen of the distal plate, wherein the multi-lumen assembly defines a third lumen radially offset at a predetermined distance from each of the proximal and distal axes at each of the first and second intersection points when the end effector is in the straight configuration, wherein the third lumen movably supports the first elongate member therethrough such that the radial spacing of the first elongate member is maintained at the predetermined distance at each of the first and second intersection points when the end effector is in the deflected position, wherein the multi-lumen assembly defines a fourth lumen radially offset at a predetermined distance from each of the proximal and distal axes at each of the first and second intersection points when the end effector is in the straight configuration, wherein the fourth lumen movably supports the second elongate member therethrough such that the radial spacing of the second elongate member is maintained at the predetermined distance at each of the first and second intersection points when the end effector is in the deflected position. Example 17 A surgical instrument, comprising: (a) an end effector; and (b) a shaft assembly, including: (i) a proximal shaft portion longitudinally extending along a proximal axis, (ii) a distal shaft portion longitudinally extending along a distal axis, wherein the end effector distally extends from the distal shaft portion, (iii) a first elongate member extending from the proximal shaft portion and toward the end effector, wherein the first elongate member is operatively connected to at least one of the distal shaft portion or the end effector and configured to be selectively moved, and (iv) an articulation section extending between the proximal and distal shaft portions and configured to articulate about a first articulation axis and about a second articulation axis distal of the first articulation axis to thereby respectively deflect the end effector along a first plane and a second plane, and wherein the articulation section includes a first lumen radially offset from each of the proximal and distal axes that longitudinally intersects each of the first and second articulation axes, wherein the first lumen movably supports the first elongate member therethrough such that the first elongate member intersects each of the first and second articulation axes for deflection of the end effector. Example 18 The surgical instrument of Example 17, wherein the first lumen spirals from the first articulation axis to the second articulation axis to define a helical lumen. Example 19 The surgical instrument of any one or more of Examples 17 through 18, wherein the first articulation axis is longitudinally offset from the second articulation axis and perpendicular to the second articulation axis. Example 20 A method of operating a surgical instrument, the surgical instrument having (a) an end effector and (b) a shaft assembly, including (i) a proximal shaft portion longitudinally extending along a proximal axis, (ii) a distal shaft portion longitudinally extending along a distal axis, wherein the end effector distally extends from the distal shaft portion, (iii) a first elongate member extending from the proximal shaft portion and toward the end effector, wherein the first elongate member is operatively connected to at least one of the distal shaft portion or the end effector and configured to be selectively moved, and (iv) an articulation section extending between the proximal and distal shaft portions and configured to articulate about a first articulation axis and about a second articulation axis distal of the first articulation axis to thereby respectively deflect the end effector along a first plane and a second plane, wherein the first articulation axis intersects the proximal axis at a first intersection point, wherein the second articulation axis intersects the distal axis at a second intersection point, and wherein the articulation section includes a first lumen radially offset at a predetermined distance from each of the proximal and distal axes at each of the first and second intersection points when the end effector is in a straight configuration with the distal axis longitudinally aligned with the proximal axis, wherein the first lumen movably supports the first elongate member therethrough such that the radial spacing of the first elongate member is maintained at the predetermined distance at each of the first and second intersection points when the end effector is deflected to a deflected configuration along at least one of the first and second planes, the method comprising: (a) actuating the first elongate member through each of the first articulation axis and the second articulation axis thereby operating the surgical instrument. III. Miscellaneous Any one or more of the teaching, expressions, embodiments, examples, etc. described herein may be combined with any one or more of the teachings, expressions, embodiments, examples, etc. described in U.S. patent application Ser. No. 16/556,661, entitled “Ultrasonic Surgical Instrument with a Multi-Planar Articulating Shaft Assembly,” filed on Aug. 30, 2019, published as U.S. Pat. Pub. No. 2021/0059709 on Mar. 4, 2021, issued as U.S. Pat. No. 11,690,642 on Jul. 4, 2023; U.S. patent application Ser. No. 16/556,667, entitled “Ultrasonic Transducer Alignment of an Articulating Ultrasonic Surgical Instrument,” filed on Aug. 30, 2019, published as U.S. Pat. Pub. No. 2021/0059710 on Mar. 4, 2021, issued as U.S. Pat. No. 11,612,409; U.S. patent application Ser. No. 16/556,625, entitled “Ultrasonic Surgical Instrument with Axisymmetric Clamping,” filed on Aug. 30, 2019, published as U.S. Pat. Pub. No. 2021/0059707 on Mar. 4, 2021, issued as U.S. Pat. No. 11,471,181 on Oct. 18, 2022; U.S. patent application Ser. No. 16/556,635, entitled “Ultrasonic Blade and Clamp Arm Alignment Features,” filed on Aug. 30, 2019, U.S. Pat. Pub. No. 2021/0059708 on Mar. 4, 2021, issued as U.S. Pat. No. 11,457,945 on Oct. 4, 2022; and/or U.S. patent application Ser. No. 16/556,727, entitled “Rotatable Linear Actuation Mechanism,” filed on Aug. 30, 2019, published as U.S. Pat. Pub. No. 2021/0059711 on Mar. 4, 2021, issued as U.S. Pat. No. 11,712,261 on Aug. 1, 2023. The disclosure of each of these applications is incorporated by reference herein. It should be understood that any of the versions of instruments described herein may include various other features in addition to or in lieu of those described above. By way of example only, in addition to the teachings above, it should be understood that the instruments described herein may be constructed and operable in accordance with at least some of the teachings of U.S. Pat. Nos. 5,322,055; 5,873,873; 5,980,510; 6,325,811; 6,773,444; 6,783,524; 9,095,367; U.S. Pub. No. 2006/0079874, now abandoned; U.S. Pub. No. 2007/0191713, now abandoned; U.S. Pub. No. 2007/0282333, now abandoned; U.S. Pub. No. 2008/0200940, now abandoned; U.S. Pat. No. 8,623,027, issued Jan. 7, 2014; U.S. Pat. No. 9,023,071, issued May 5, 2015; U.S. Pat. No. 8,461,744, issued Jun. 11, 2013; U.S. Pat. No. 9,381,058, issued Jul. 5, 2016; U.S. Pub. No. 2012/0116265, now abandoned; U.S. Pat. No. 9,393,037, issued Jul. 19, 2016; U.S. Pat. No. 10,172,636, issued Jan. 8, 2019; and/or U.S. Pat. App. No. 61/410,603. The disclosures of each of the foregoing patents, publications, and applications are incorporated by reference herein. It should also be understood that the instruments described herein may have various structural and functional similarities with the HARMONIC ACE® Ultrasonic Shears, the HARMONIC WAVE® Ultrasonic Shears, the HARMONIC FOCUS® Ultrasonic Shears, and/or the HARMONIC SYNERGY® Ultrasonic Blades. Furthermore, the instruments described herein may have various structural and functional similarities with the devices taught in any of the other references that are cited and incorporated by reference herein. To the extent that there is some degree of overlap between the teachings of the references cited herein, the HARMONIC ACE® Ultrasonic Shears, the HARMONIC WAVE® Ultrasonic Shears, the HARMONIC FOCUS® Ultrasonic Shears, and/or the HARMONIC SYNERGY® Ultrasonic Blades, and the teachings herein relating to the instruments described herein, there is no intent for any of the description herein to be presumed as admitted prior art. Several teachings herein will in fact go beyond the scope of the teachings of the references cited herein and the HARMONIC ACE® Ultrasonic Shears, the HARMONIC WAVE® Ultrasonic Shears, the HARMONIC FOCUS® Ultrasonic Shears, and the HARMONIC SYNERGY® Ultrasonic Blades. It should be appreciated that any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material. Versions of the devices described above may have application in conventional medical treatments and procedures conducted by a medical professional, as well as application in robotic-assisted medical treatments and procedures. By way of example only, various teachings herein may be readily incorporated into another example of a robotic surgical system, and those of ordinary skill in the art will recognize that various teachings herein may be readily combined with various teachings of any of the following: U.S. Pat. No. 8,844,789, entitled “Automated End Effector Component Reloading System for Use with a Robotic System,” issued Sep. 30, 2014, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 8,820,605, entitled “Robotically-Controlled Surgical Instruments,” issued Sep. 2, 2014, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 8,616,431, entitled “Shiftable Drive Interface for Robotically-Controlled Surgical Tool,” issued Dec. 31, 2013, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 8,573,461, entitled “Surgical Stapling Instruments with Cam-Driven Staple Deployment Arrangements,” issued Nov. 5, 2013, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 8,602,288, entitled “Robotically-Controlled Motorized Surgical End Effector System with Rotary Actuated Closure Systems Having Variable Actuation Speeds,” issued Dec. 10, 2013, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 9,301,759, entitled “Robotically-Controlled Surgical Instrument with Selectively Articulatable End Effector,” issued Apr. 5, 2016, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 8,783,541, entitled “Robotically-Controlled Surgical End Effector System,” issued Jul. 22, 2014, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 8,479,969, entitled “Drive Interface for Operably Coupling a Manipulatable Surgical Tool to a Robot,” issued Jul. 9, 2013; U.S. Pat. No. 8,800,838, entitled “Robotically-Controlled Cable-Based Surgical End Effectors,” issued Aug. 12, 2014, the disclosure of which is incorporated by reference herein; and/or U.S. Pat. No. 8,573,465, entitled “Robotically-Controlled Surgical End Effector System with Rotary Actuated Closure Systems,” issued Nov. 5, 2013, the disclosure of which is incorporated by reference herein. Versions described above may be designed to be disposed of after a single use, or they can be designed to be used multiple times. Versions may, in either or both cases, be reconditioned for reuse after at least one use. Reconditioning may include any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, some versions of the device may be disassembled, and any number of the particular pieces or parts of the device may be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, some versions of the device may be reassembled for subsequent use either at a reconditioning facility, or by an operator immediately prior to a procedure. Those skilled in the art will appreciate that reconditioning of a device may utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application. By way of example only, versions described herein may be sterilized before and/or after a procedure. In one sterilization technique, the device is placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and device may then be placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation may kill bacteria on the device and in the container. The sterilized device may then be stored in the sterile container for later use. A device may also be sterilized using any other technique known in the art, including but not limited to beta or gamma radiation, ethylene oxide, or steam. Having shown and described various embodiments of the present invention, further adaptations of the methods and systems described herein may be accomplished by appropriate modifications by one of ordinary skill in the art without departing from the scope of the present invention. Several of such potential modifications have been mentioned, and others will be apparent to those skilled in the art. For instance, the examples, embodiments, geometrics, materials, dimensions, ratios, steps, and the like discussed above are illustrative and are not required. Accordingly, the scope of the present invention should be considered in terms of the following claims and is understood not to be limited to the details of structure and operation shown and described in the specification and drawings.